Chemical Engineering Research and Design, Available
online 20 March 2012, In Press, Corrected Proof
Kinetic
modeling of heavy reformate conversion into xylenes over mordenite-ZSM5 based
catalysts
U.A. Al-Mubaiyedh a, b, S.A. Ali a, S.S. Al-Khattaf a, b, ,
a Center of Research Excellence in Petroleum Refining and Petrochemicals, King
Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
b Chemical Engineering Department, King Fahd University of Petroleum &
Minerals, Dhahran 31261, Saudi Arabia
Abstract
Authors investigated conversion
of commercial heavy reformate into
xylenes in a fluidized-bed batch reactor to develop a kinetic model.
Results of the mathematical
model closely match the experimental data, based on statistically significant
estimate of the kinetic parameters, which indicates that the set of assumptions
made for kinetic modeling are valid. The order of apparent activation energies,
Eparing ≫ Edealkylation = Edisproportionation > Etransalkylation, can be ascribed to the relative size
of the reactant molecules involved in these reactions.
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Saturday, April 28, 2012
Soft Sensor Development for the Estimation of Benzene Content in Catalytic Reformate
Ind. Eng. Chem. Res., 2012, 51 (7), pp 3007–3014
Soft Sensor Development for the Estimation of Benzene Content in Catalytic Reformate
Željka Ujević Andrijić*†, Tomislav Rolich‡, and Nenad Bolf†
zujevic@fkit.hr
† Department of Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska c. 16/5A, 10000 Zagreb, Croatia
‡ Department of Fundamental Natural and Engineering Sciences, Faculty of Textile Technology, University of Zagreb, Prilaz baruna Filipovića 28a, 10000 Zagreb, Croatia
Abstract
Researchers developed soft sensors for the estimation of benzene content of light reformate to compensate for the fact that on-line analyzers are often unavailable, and laboratory analyses are infrequently obtained.
They used linear and nonlinear identification methods to develop the sensors. They produced experimental data from the refinery distributed control system (DCS), including continuously measured variables and analyzer assays available on-line. They describe development of a finite impulse response (FIR) model, an output error (OE) model, and a Hammerstein–Wiener (HW) model.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/ie202362d
Soft Sensor Development for the Estimation of Benzene Content in Catalytic Reformate
Željka Ujević Andrijić*†, Tomislav Rolich‡, and Nenad Bolf†
zujevic@fkit.hr
† Department of Measurements and Process Control, Faculty of Chemical Engineering and Technology, University of Zagreb, Savska c. 16/5A, 10000 Zagreb, Croatia
‡ Department of Fundamental Natural and Engineering Sciences, Faculty of Textile Technology, University of Zagreb, Prilaz baruna Filipovića 28a, 10000 Zagreb, Croatia
Abstract
Researchers developed soft sensors for the estimation of benzene content of light reformate to compensate for the fact that on-line analyzers are often unavailable, and laboratory analyses are infrequently obtained.
They used linear and nonlinear identification methods to develop the sensors. They produced experimental data from the refinery distributed control system (DCS), including continuously measured variables and analyzer assays available on-line. They describe development of a finite impulse response (FIR) model, an output error (OE) model, and a Hammerstein–Wiener (HW) model.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/ie202362d
Process For The Production Of Para-Xylene
CATEGORY: PARAXYLENE
PATENT
Process For The Production Of Para-Xylene
United States Patent Application 20120029257
Inventors:
Chen, Cong-yan (Alameda, CA, US)
Miller, Stephen J. (San Francisco, CA, US)
Ziemer, James N. (Martinez, CA, US)
Liang, Ann J. (Walnut Creek, CA, US)
Application Number: 12/845618
Publication Date:02/02/2012
Assignee: Chevron U.S.A. Inc.
Abstract:
A reforming process using a medium pore zeolite under conditions to facilitate the conversion of C8 paraffinic compounds to para-xylene is provided. Para-xylene is produced at greater than thermodynamic equilibrium concentrations using the process.
Description:FIELD OF THE INVENTION
The present invention provides a process for the production of para-xylene from a C8 containing paraffinic feedstock. A shape selective catalyst comprising a medium pore zeolite with a silica to alumina ratio of at least 40:1 is used during the catalytic reaction.
BACKGROUND
Catalytic reforming is one of the basic petroleum refining processes for upgrading light hydrocarbon feedstocks, frequently referred to as naphtha feedstocks. Products from catalytic reforming can include high octane gasoline useful as automobile fuel, aromatics (for example benzene, toluene, xylenes and ethylbenzene), and/or hydrogen. Reactions typically involved in catalytic reforming include dehydrocylization, isomerization and dehydrogenation of naphtha range hydrocarbons, with dehydrocyclization and dehydrogenation of linear and slightly branched alkanes and dehydrogenation of cycloparaffins leading to the production of aromatics. Dealkylation and hydrocracking during catalytic reforming are generally undesirable due to the low value of the resulting light hydrocarbon products.
Xylene is composed of three different isomers, para-xylene (PX), meta-xylene (MX), and ortho-xylene (OX). Of the xylene isomers, para-xylene (PX) is of particular value since it is useful in the manufacture of terephthalic acid which is an intermediate in the manufacture of synthetic fibers. One current method for producing para-xylene is using naphtha reforming where mixed aromatics are produced. An aromatic containing stream can be separated and the stream used as a feedstock for the production of para-xylene. Generally, para-xylene is produced along with other xylene isomers and toluene. Purified toluene may be selectively or non-selectively disproportionated to produce para-xylene and benzene. Para-xylene may also be produced from mixed xylenes by isomerization followed by separation of the para-xylene from the meta and ortho isomers.
One known method for producing xylenes involves the alkylation of toluene with methanol over a solid acid catalyst. The alkylation of toluene with methanol over cation-exchanged zeolite Y has been described by, for example, Yashima et al. in the Journal of Catalysis 16, 273-280 (1970). Under optimized reaction conditions, the amount of para-xylene produced was approximately 50 wt % of the xylene product mixture.
U.S. Pat. No. 7,119,239 and U.S. Pat. No. 7,176,339 disclose a process for the production of xylenes from reformate. The process is carried out by methylating, under conditions effective for the methylation, the benzene/toluene present in the reformate, to produce a resulting product having a higher xylenes content than the reformate. Greater than equilibrium amounts of para-xylene can be produced by the process. U.S. Pat. No. 7,186,873 discloses a process for the production of xylenes from reformate by reactive distillation. The process is carried out by methylating the benzene/toluene present in the reformate in a reactive distillation zone and under reactive distillation conditions to produce a resulting product having a higher xylenes content than the reformate. Greater than equilibrium amounts of para-xylene can be produced by the process.
Given the higher demand for para-xylene as compared with other xylene isomers, there is significant commercial interest in maximizing para-xylene production from any given source of C8 feedstocks. However, there are two major technical challenges in achieving this goal of maximizing para-xylene yield. Firstly, the four C8 aromatic compounds, para-xylene, meta-xylene, ortho-xylene, and ethylbenzene, are usually present in concentrations dictated by thermodynamic equilibria, where meta-xylene comprises about 60 wt. %, para-xylene about 14 wt. %, ortho-xylene about 9 wt. %, and ethylbenzene about 17 wt. % of the C8 aromatic compounds. As a result, the para-xylene yield is limited from any refinery C8 stream unless additional processing steps are used to increase the amount of para-xylene and/or to improve the para-xylene recovery efficiency. Secondly, the C8 aromatics are difficult to separate due to their similar chemical structures and physical properties and identical molecular weights.
A variety of methods are known to increase the concentration of para-xylene in a C8 aromatics product stream. These methods normally involve recycling the product stream between a separation step, in which at least part of the para-xylene is recovered to produce a para-xylene-depleted stream, and a xylene isomerization step, in which the para-xylene content of the para-xylene-depleted stream is returned back towards equilibrium concentration, typically by contact with a molecular sieve catalyst. However, the commercial utility of these methods depends on the efficiency, cost effectiveness and rapidity of the separation step which, as discussed above, is complicated by the chemical and physical similarity of the different C8 isomers.
A variety of methods are known in the art to purify para-xylene from less valuable xylene isomers and ethylbenzene. Fractional distillation is a commonly used method for separating different components in chemical mixtures. However, it is difficult to use conventional fractional distillation technologies to separate ethylbenzene (EB) and the different xylene isomers because the boiling points of the four C8 aromatics fall within a very narrow range, namely from about 136° C. to about 144° C. In particular, the boiling points of para-xylene and EB are about 2° C. apart, whereas the boiling points of para-xylene and meta-xylene are only about 1° C. apart. As a result, large equipment, significant energy consumption, and/or substantial recycles would be required for fractional distillation to provide effective C8 aromatic separation. Another method for separating the para-xylene from other xylene isomers and ethylbenzene involves crystallizing the para-xylene. U.S. Pat. No. 5,811,629 discloses a process for purifying para-xylene from C8 aromatics involving at least two crystallization stages as well as at least one recycle step and at least one additional separation step. The above described methods are time consuming and costly. It is desirable to increase the amount of para-xylene in the product stream so as to minimize the number of recycle and purification steps needed to obtain pure para-xylene product.
It has been found that the use of a low acidity medium pore zeolite catalyst with a silica to alumina ratio of at least about 40 to 1, increases the yield of para-xylene from a given C8 paraffinic feedstock.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0029257.html
PATENT
Process For The Production Of Para-Xylene
United States Patent Application 20120029257
Inventors:
Chen, Cong-yan (Alameda, CA, US)
Miller, Stephen J. (San Francisco, CA, US)
Ziemer, James N. (Martinez, CA, US)
Liang, Ann J. (Walnut Creek, CA, US)
Application Number: 12/845618
Publication Date:02/02/2012
Assignee: Chevron U.S.A. Inc.
Abstract:
A reforming process using a medium pore zeolite under conditions to facilitate the conversion of C8 paraffinic compounds to para-xylene is provided. Para-xylene is produced at greater than thermodynamic equilibrium concentrations using the process.
Description:FIELD OF THE INVENTION
The present invention provides a process for the production of para-xylene from a C8 containing paraffinic feedstock. A shape selective catalyst comprising a medium pore zeolite with a silica to alumina ratio of at least 40:1 is used during the catalytic reaction.
BACKGROUND
Catalytic reforming is one of the basic petroleum refining processes for upgrading light hydrocarbon feedstocks, frequently referred to as naphtha feedstocks. Products from catalytic reforming can include high octane gasoline useful as automobile fuel, aromatics (for example benzene, toluene, xylenes and ethylbenzene), and/or hydrogen. Reactions typically involved in catalytic reforming include dehydrocylization, isomerization and dehydrogenation of naphtha range hydrocarbons, with dehydrocyclization and dehydrogenation of linear and slightly branched alkanes and dehydrogenation of cycloparaffins leading to the production of aromatics. Dealkylation and hydrocracking during catalytic reforming are generally undesirable due to the low value of the resulting light hydrocarbon products.
Xylene is composed of three different isomers, para-xylene (PX), meta-xylene (MX), and ortho-xylene (OX). Of the xylene isomers, para-xylene (PX) is of particular value since it is useful in the manufacture of terephthalic acid which is an intermediate in the manufacture of synthetic fibers. One current method for producing para-xylene is using naphtha reforming where mixed aromatics are produced. An aromatic containing stream can be separated and the stream used as a feedstock for the production of para-xylene. Generally, para-xylene is produced along with other xylene isomers and toluene. Purified toluene may be selectively or non-selectively disproportionated to produce para-xylene and benzene. Para-xylene may also be produced from mixed xylenes by isomerization followed by separation of the para-xylene from the meta and ortho isomers.
One known method for producing xylenes involves the alkylation of toluene with methanol over a solid acid catalyst. The alkylation of toluene with methanol over cation-exchanged zeolite Y has been described by, for example, Yashima et al. in the Journal of Catalysis 16, 273-280 (1970). Under optimized reaction conditions, the amount of para-xylene produced was approximately 50 wt % of the xylene product mixture.
U.S. Pat. No. 7,119,239 and U.S. Pat. No. 7,176,339 disclose a process for the production of xylenes from reformate. The process is carried out by methylating, under conditions effective for the methylation, the benzene/toluene present in the reformate, to produce a resulting product having a higher xylenes content than the reformate. Greater than equilibrium amounts of para-xylene can be produced by the process. U.S. Pat. No. 7,186,873 discloses a process for the production of xylenes from reformate by reactive distillation. The process is carried out by methylating the benzene/toluene present in the reformate in a reactive distillation zone and under reactive distillation conditions to produce a resulting product having a higher xylenes content than the reformate. Greater than equilibrium amounts of para-xylene can be produced by the process.
Given the higher demand for para-xylene as compared with other xylene isomers, there is significant commercial interest in maximizing para-xylene production from any given source of C8 feedstocks. However, there are two major technical challenges in achieving this goal of maximizing para-xylene yield. Firstly, the four C8 aromatic compounds, para-xylene, meta-xylene, ortho-xylene, and ethylbenzene, are usually present in concentrations dictated by thermodynamic equilibria, where meta-xylene comprises about 60 wt. %, para-xylene about 14 wt. %, ortho-xylene about 9 wt. %, and ethylbenzene about 17 wt. % of the C8 aromatic compounds. As a result, the para-xylene yield is limited from any refinery C8 stream unless additional processing steps are used to increase the amount of para-xylene and/or to improve the para-xylene recovery efficiency. Secondly, the C8 aromatics are difficult to separate due to their similar chemical structures and physical properties and identical molecular weights.
A variety of methods are known to increase the concentration of para-xylene in a C8 aromatics product stream. These methods normally involve recycling the product stream between a separation step, in which at least part of the para-xylene is recovered to produce a para-xylene-depleted stream, and a xylene isomerization step, in which the para-xylene content of the para-xylene-depleted stream is returned back towards equilibrium concentration, typically by contact with a molecular sieve catalyst. However, the commercial utility of these methods depends on the efficiency, cost effectiveness and rapidity of the separation step which, as discussed above, is complicated by the chemical and physical similarity of the different C8 isomers.
A variety of methods are known in the art to purify para-xylene from less valuable xylene isomers and ethylbenzene. Fractional distillation is a commonly used method for separating different components in chemical mixtures. However, it is difficult to use conventional fractional distillation technologies to separate ethylbenzene (EB) and the different xylene isomers because the boiling points of the four C8 aromatics fall within a very narrow range, namely from about 136° C. to about 144° C. In particular, the boiling points of para-xylene and EB are about 2° C. apart, whereas the boiling points of para-xylene and meta-xylene are only about 1° C. apart. As a result, large equipment, significant energy consumption, and/or substantial recycles would be required for fractional distillation to provide effective C8 aromatic separation. Another method for separating the para-xylene from other xylene isomers and ethylbenzene involves crystallizing the para-xylene. U.S. Pat. No. 5,811,629 discloses a process for purifying para-xylene from C8 aromatics involving at least two crystallization stages as well as at least one recycle step and at least one additional separation step. The above described methods are time consuming and costly. It is desirable to increase the amount of para-xylene in the product stream so as to minimize the number of recycle and purification steps needed to obtain pure para-xylene product.
It has been found that the use of a low acidity medium pore zeolite catalyst with a silica to alumina ratio of at least about 40 to 1, increases the yield of para-xylene from a given C8 paraffinic feedstock.
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Integration of Cyclic Dehydrogenation Process with FCC for Dehydrogenation of Refinery Paraffins
PATENT
Integration of Cyclic Dehydrogenation Process with FCC for Dehydrogenation of Refinery Paraffins
United States Patent Application 20120071701
Inventors: Glover, Bryan K. (Algonquin, IL, US)
Application Number: 12/886966
Publication Date: 03/22/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
A process for increasing light olefin yields from the fluidized catalytic cracking process. The process combines small units to treat the paraffinic components in the product streams from the fluidized cracking process. The paraffins are dehydrogenated and light olefins are separated. Heavier olefins are passed to an olefin cracking unit for increasing the yields of ethylene and propylene.
Description:
FIELD OF THE INVENTION
The field of the invention is the production of light olefins. In particular, the field is the production of light olefins using the cracking of heavier hydrocarbons, and the processing of intermediate streams from the cracking process.
BACKGROUND OF THE INVENTION
Ethylene and propylene, light olefin hydrocarbons with two or three atoms per molecule, respectively, are important chemicals for use in the production of other useful materials, such as polyethylene and polypropylene.
Polyethylene and polypropylene are two of the
most common plastics found in use today and have a wide variety of uses both as
a material fabrication and as a material for packaging. Other uses for ethylene
and propylene include the production of vinyl chloride, ethylene oxide,
ethylbenzene and alcohol. Steam cracking or pyrolysis of hydrocarbons produces
most of the ethylene and some propylene. One of the disadvantages of steam
cracking is the low ratio of propylene to ethylene. Hydrocarbons used as
feedstock for light olefin production include natural gas, petroleum liquids,
and carbonaceous materials including coal, recycled plastics or any organic
material.
An ethylene plant is a very complex combination of reaction and gas recovery systems. The feedstock is charged to a cracking zone in the presence of steam at effective thermal conditions to produce a pyrolysis reactor effluent gas mixture. The pyrolysis reactor effluent gas mixture is stabilized and separated into purified components through a sequence of cryogenic and conventional fractionation steps. A typical ethylene separation section of an ethylene plant containing both cryogenic and conventional fractionation steps to recover an ethylene product with a purity exceeding 99.5% ethylene is described in an article by V. Kaiser and M. Picciotti, entitled, “Better Ethylene Separation Unit.” The article appeared in HYDROCARBON PROCESSING MAGAZINE, November 1988, pages 57-61 and is hereby incorporated by reference.
Methods are known for increasing the conversion of portions of the products of the ethylene production from a zeolitic cracking process to produce more propylene by a disproportionation or metathesis of olefins. Such processes are disclosed in U.S. Pat. No. 5,026,935 and U.S. Pat. No. 5,026,936 wherein a metathesis reaction step is employed in combination with a catalytic cracking step to produce more propylene by the metathesis of C2 and C4 olefins obtained from cracking. The catalytic cracking step employs a zeolitic catalyst to convert a hydrocarbon stream having 4 or more carbon atoms per molecule to produce olefins having fewer carbon atoms per molecule. The hydrocarbon feedstream to the zeolitic catalyst typically contains a mixture of 40 to 100 wt-% paraffins having 4 or more carbon atoms per molecule and 0 to 60 wt-% olefins having 4 or more carbon atoms per molecule. In U.S. Pat. No. 5,043,522, it is disclosed that the preferred catalyst for such a zeolitic cracking process is an acid zeolite, examples includes several of the ZSM-type zeolites or the borosilicates. Of the ZSM-type zeolites, ZSM-5 was preferred.
SUMMARY OF THE INVENTION
The present invention is a process for improving the light olefin yields associated with fluidized catalytic cracking. The fluidized catalytic cracking (FCC) process is used to convert larger hydrocarbons that are typically above the naphtha boiling range to light olefins. However, there are significant amounts of by-products that are passed to other processing units. The light olefin yields can be increased by adding small units to process some of the by-products, while utilizing the equipment associated with the FCC process for product recovery and heat exchange. The process includes separating the effluent stream from an FCC unit to create a first process stream having light olefins and a second process stream having olefins and paraffins in the C4 to C12 range. The second process stream is passed to an olefin conversion reactor to generate ethylene and propylene from the C4 to C12 process stream. The light olefins are separated and an olefin depleted stream is generated. The olefin depleted stream has a relative increased paraffinic content, and is passed to a dehydrogenation reactor to generate a third process stream with an increased olefin content. The third process stream is then passed to the olefin conversion reactor.
In one embodiment, the olefin conversion reactor is an olefin cracking reactor to convert the larger olefins to light olefins. The process can also use a first olefin conversion reactor that is either an olefin cracking reactor, alkylation reactor, or an etherification reactor, and a second olefin conversion reactor which can be the same as the first olefin conversion reactor or different type of reactor from those listed above for the conversion of olefins.
Additional objects, embodiments and details of this invention can be obtained from the following detailed description of the invention.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0071701.html
Integration of Cyclic Dehydrogenation Process with FCC for Dehydrogenation of Refinery Paraffins
United States Patent Application 20120071701
Inventors: Glover, Bryan K. (Algonquin, IL, US)
Application Number: 12/886966
Publication Date: 03/22/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
A process for increasing light olefin yields from the fluidized catalytic cracking process. The process combines small units to treat the paraffinic components in the product streams from the fluidized cracking process. The paraffins are dehydrogenated and light olefins are separated. Heavier olefins are passed to an olefin cracking unit for increasing the yields of ethylene and propylene.
Description:
FIELD OF THE INVENTION
The field of the invention is the production of light olefins. In particular, the field is the production of light olefins using the cracking of heavier hydrocarbons, and the processing of intermediate streams from the cracking process.
BACKGROUND OF THE INVENTION
Ethylene and propylene, light olefin hydrocarbons with two or three atoms per molecule, respectively, are important chemicals for use in the production of other useful materials, such as polyethylene and polypropylene.
An ethylene plant is a very complex combination of reaction and gas recovery systems. The feedstock is charged to a cracking zone in the presence of steam at effective thermal conditions to produce a pyrolysis reactor effluent gas mixture. The pyrolysis reactor effluent gas mixture is stabilized and separated into purified components through a sequence of cryogenic and conventional fractionation steps. A typical ethylene separation section of an ethylene plant containing both cryogenic and conventional fractionation steps to recover an ethylene product with a purity exceeding 99.5% ethylene is described in an article by V. Kaiser and M. Picciotti, entitled, “Better Ethylene Separation Unit.” The article appeared in HYDROCARBON PROCESSING MAGAZINE, November 1988, pages 57-61 and is hereby incorporated by reference.
Methods are known for increasing the conversion of portions of the products of the ethylene production from a zeolitic cracking process to produce more propylene by a disproportionation or metathesis of olefins. Such processes are disclosed in U.S. Pat. No. 5,026,935 and U.S. Pat. No. 5,026,936 wherein a metathesis reaction step is employed in combination with a catalytic cracking step to produce more propylene by the metathesis of C2 and C4 olefins obtained from cracking. The catalytic cracking step employs a zeolitic catalyst to convert a hydrocarbon stream having 4 or more carbon atoms per molecule to produce olefins having fewer carbon atoms per molecule. The hydrocarbon feedstream to the zeolitic catalyst typically contains a mixture of 40 to 100 wt-% paraffins having 4 or more carbon atoms per molecule and 0 to 60 wt-% olefins having 4 or more carbon atoms per molecule. In U.S. Pat. No. 5,043,522, it is disclosed that the preferred catalyst for such a zeolitic cracking process is an acid zeolite, examples includes several of the ZSM-type zeolites or the borosilicates. Of the ZSM-type zeolites, ZSM-5 was preferred.
The present invention is a process for improving the light olefin yields associated with fluidized catalytic cracking. The fluidized catalytic cracking (FCC) process is used to convert larger hydrocarbons that are typically above the naphtha boiling range to light olefins. However, there are significant amounts of by-products that are passed to other processing units. The light olefin yields can be increased by adding small units to process some of the by-products, while utilizing the equipment associated with the FCC process for product recovery and heat exchange. The process includes separating the effluent stream from an FCC unit to create a first process stream having light olefins and a second process stream having olefins and paraffins in the C4 to C12 range. The second process stream is passed to an olefin conversion reactor to generate ethylene and propylene from the C4 to C12 process stream. The light olefins are separated and an olefin depleted stream is generated. The olefin depleted stream has a relative increased paraffinic content, and is passed to a dehydrogenation reactor to generate a third process stream with an increased olefin content. The third process stream is then passed to the olefin conversion reactor.
In one embodiment, the olefin conversion reactor is an olefin cracking reactor to convert the larger olefins to light olefins. The process can also use a first olefin conversion reactor that is either an olefin cracking reactor, alkylation reactor, or an etherification reactor, and a second olefin conversion reactor which can be the same as the first olefin conversion reactor or different type of reactor from those listed above for the conversion of olefins.
Additional objects, embodiments and details of this invention can be obtained from the following detailed description of the invention.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0071701.html
SMSI-like behavior and Ni promotion effect on NiZnAl catalysts in steam reforming of methanol
CATEGORY: METHANOL
Catalysis Communications, Volume 22, 10 May 2012, Pages 68–73
SMSI-like behavior and Ni promotion effect on NiZnAl catalysts in steam reforming of methanol
Yong Men, , Mei Yang
Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023, Dalian, PR China
Abstract
Researchers developed a series of NiZnAl catalysts for hydrogen production by methanol steam reforming within microchannel reactor. Results indicate that the coexistence of Ni and Zn in bimetallic catalysts results in superior catalytic performance for hydrogen production compared with monometallic catalysts
This is in spite of the fact the former possesses the lower surface area. The difference between the catalytic performances could mainly be attributed to the Ni promotion effect associated with SMSI-like geometric effects and interpreted by a hypothesized encapsulation model corroborated by the characterizations.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S1566736712000696
Catalysis Communications, Volume 22, 10 May 2012, Pages 68–73
SMSI-like behavior and Ni promotion effect on NiZnAl catalysts in steam reforming of methanol
Yong Men, , Mei Yang
Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023, Dalian, PR China
Abstract
Researchers developed a series of NiZnAl catalysts for hydrogen production by methanol steam reforming within microchannel reactor. Results indicate that the coexistence of Ni and Zn in bimetallic catalysts results in superior catalytic performance for hydrogen production compared with monometallic catalysts
This is in spite of the fact the former possesses the lower surface area. The difference between the catalytic performances could mainly be attributed to the Ni promotion effect associated with SMSI-like geometric effects and interpreted by a hypothesized encapsulation model corroborated by the characterizations.
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High Octane Aviation Fuel Composition
PATENT
High Octane Aviation Fuel Composition
United States Patent Application 20120029251
Inventors:
Hemighaus, Gregory (Richmond, CA, US)
Cannella, William (Orinda, CA, US)
Application Number: 12/970685
Publication Date:02/02/2012
Assignee: Chevron U.S.A. Inc.
Abstract:
An unleaded aviation fuel composition, containing at least one saturated branched aliphatic hydrocarbon having a carbon number in the C4 to C10 range, further contains sufficient m-xylene to yield a fuel having a MON of at least 98. A process is further provided for producing the unleaded aviation fuel composition by admixing a m-xylene enriched liquid with alkylate.
FIELD OF THE INVENTION
The present invention relates to fuels, particularly aviation gasoline (aviation fuel) formulations, which contain reduced amounts of tetraethyl lead.
BACKGROUND
Aviation gasoline (aviation fuel) generally contains an aviation alkylate base fuel and a lead-based additive package. A conventional aviation fuel formulation contains light alkylate, toluene, C4 to C5 paraffins and tetraethyl lead. Current formulations comprise 75-92 vol. % light alkylate, 5-18 vol. % toluene, 3-20 vol. % C4 to C5 paraffins and 2-4 ml/gallon tetraethyl lead (TEL). The industry standard Grade 100 aviation gasoline contains up to 4 ml of TEL/gallon of fuel while Grade 100LL (low lead) aviation gasoline contains up to 2 ml TEL/gallon of fuel. Tetraethyl lead is conventionally added as an octane booster to improve the anti-knock properties of the aviation fuel over the anti-knock properties of the aviation alkylate base fuel. Specifications for aviation gasoline are detailed in ASTM D910-07a. Grade 100 aviation gasoline and Grade 100LL aviation gasoline are two grades of aviation gasoline having properties described by the specification.
The use of tetraethyl lead in fuels, particularly in automotive gasolines, has been restricted for many years due, in part, to health and environmental concerns as well as catalyst poisoning effects in automobile catalytic converters. Aviation gasolines have been allowed to contain tetraethyl lead since no suitable substitute has been found with adequate knock resistance to allow the current fleet of aircraft engines to operate properly. Current U.S. regulations set a maximum amount of tetraethyl lead in aviation fuels at 4.0 ml TEL/gallon. The continued use of tetraethyl lead nonetheless remains an environmental and health concern which has not been completely resolved. The possibility of further restrictions, or a prohibition, on the use of tetraethyl lead in aviation gasolines therefore exists.
Alternatives to the use of tetraethyl lead are known. For example, methylcyclopentadienyl manganese tricarbonyl (MMT) has been used as an antiknock agent in motor fuels since around 1975, first as a supplement to leaded agents, and then as a replacement to produce lead-free gasoline. However, questions have also been raised concerning the production of undesirable emissions using MMT.
One possible option is to hydrogenate di-isobutylene to form a mixture of isoparaffins, predominately 2,2,4-trimethylpentane or “iso-octane.” Iso-octane derived from such a process may then be used to form a suitable aviation gasoline composition.
Aromatic amines and alkyl ethers have been proposed as substitutes for tetraethyl lead. These also have been found to have environmental and performance limitations as aviation gasoline additives.
In view of the current limitations placed on the use of tetraethyl lead it is desirable to produce aviation fuel compositions which contain reduced levels of lead, or do not require the presence of lead-based additives.
SUMMARY OF THE INVENTION
Accordingly, an aviation fuel composition is provided which is free of added lead and has a MON of at least 98 and which includes a m-xylene admixture with at least one saturated branched aliphatic hydrocarbon having a carbon number in the C4 to C10 range.
In addition, a process is provided for producing an unleaded aviation fuel composition comprising admixing m-xylene with at least one saturated branched aliphatic hydrocarbon having a carbon number in the C4 to C10 range to yield an aviation fuel having an MON of at least 98.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0029251.html
High Octane Aviation Fuel Composition
United States Patent Application 20120029251
Inventors:
Hemighaus, Gregory (Richmond, CA, US)
Cannella, William (Orinda, CA, US)
Application Number: 12/970685
Publication Date:02/02/2012
Assignee: Chevron U.S.A. Inc.
Abstract:
An unleaded aviation fuel composition, containing at least one saturated branched aliphatic hydrocarbon having a carbon number in the C4 to C10 range, further contains sufficient m-xylene to yield a fuel having a MON of at least 98. A process is further provided for producing the unleaded aviation fuel composition by admixing a m-xylene enriched liquid with alkylate.
FIELD OF THE INVENTION
The present invention relates to fuels, particularly aviation gasoline (aviation fuel) formulations, which contain reduced amounts of tetraethyl lead.
BACKGROUND
Aviation gasoline (aviation fuel) generally contains an aviation alkylate base fuel and a lead-based additive package. A conventional aviation fuel formulation contains light alkylate, toluene, C4 to C5 paraffins and tetraethyl lead. Current formulations comprise 75-92 vol. % light alkylate, 5-18 vol. % toluene, 3-20 vol. % C4 to C5 paraffins and 2-4 ml/gallon tetraethyl lead (TEL). The industry standard Grade 100 aviation gasoline contains up to 4 ml of TEL/gallon of fuel while Grade 100LL (low lead) aviation gasoline contains up to 2 ml TEL/gallon of fuel. Tetraethyl lead is conventionally added as an octane booster to improve the anti-knock properties of the aviation fuel over the anti-knock properties of the aviation alkylate base fuel. Specifications for aviation gasoline are detailed in ASTM D910-07a. Grade 100 aviation gasoline and Grade 100LL aviation gasoline are two grades of aviation gasoline having properties described by the specification.
The use of tetraethyl lead in fuels, particularly in automotive gasolines, has been restricted for many years due, in part, to health and environmental concerns as well as catalyst poisoning effects in automobile catalytic converters. Aviation gasolines have been allowed to contain tetraethyl lead since no suitable substitute has been found with adequate knock resistance to allow the current fleet of aircraft engines to operate properly. Current U.S. regulations set a maximum amount of tetraethyl lead in aviation fuels at 4.0 ml TEL/gallon. The continued use of tetraethyl lead nonetheless remains an environmental and health concern which has not been completely resolved. The possibility of further restrictions, or a prohibition, on the use of tetraethyl lead in aviation gasolines therefore exists.
Alternatives to the use of tetraethyl lead are known. For example, methylcyclopentadienyl manganese tricarbonyl (MMT) has been used as an antiknock agent in motor fuels since around 1975, first as a supplement to leaded agents, and then as a replacement to produce lead-free gasoline. However, questions have also been raised concerning the production of undesirable emissions using MMT.
One possible option is to hydrogenate di-isobutylene to form a mixture of isoparaffins, predominately 2,2,4-trimethylpentane or “iso-octane.” Iso-octane derived from such a process may then be used to form a suitable aviation gasoline composition.
Aromatic amines and alkyl ethers have been proposed as substitutes for tetraethyl lead. These also have been found to have environmental and performance limitations as aviation gasoline additives.
In view of the current limitations placed on the use of tetraethyl lead it is desirable to produce aviation fuel compositions which contain reduced levels of lead, or do not require the presence of lead-based additives.
SUMMARY OF THE INVENTION
Accordingly, an aviation fuel composition is provided which is free of added lead and has a MON of at least 98 and which includes a m-xylene admixture with at least one saturated branched aliphatic hydrocarbon having a carbon number in the C4 to C10 range.
In addition, a process is provided for producing an unleaded aviation fuel composition comprising admixing m-xylene with at least one saturated branched aliphatic hydrocarbon having a carbon number in the C4 to C10 range to yield an aviation fuel having an MON of at least 98.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0029251.html
Improving middle distillate yields via the direct hydrotreating of full crude oil
Improving middle distillate yields via the direct hydrotreating of
full crude oil
16 January 2011
Researchers at the University of Bradford (UK) are proposing a method for increasing the yield of middle distillates (such as car fuel, jet fuel, and diesel fuel) from the refinery by applying catalytic hydrotreating (HDT) to the full crude oil, rather than the now common application of hydrotreating processes to oil fractions a (i.e., after the separation of crude oil into its fractions, such as gasoline, kerosene, and light and heavy gas oils).
In a study reported in a paper in the ACS journal Energy & Fuels, the team found that their process showed greater yield of desirable middle distillates compared to the yield produced by conventional methods and, consequently, a decrease in the yield of less-desirable reduced crude residue (RCR). They also noted that the specifications of RCR produced by the direct hydrotreating of crude oil are better than the specifications of RCR produced by conventional processes; levels of sulfur, nitrogen, metals, and asphaltene are much lower in comparison to the contents of RCR produced by conventional methods, allowing for the production of good fuel oils.
Free Full Text Source: http://www.greencarcongress.com/2011/01/jarullah-20110115.html
16 January 2011
Researchers at the University of Bradford (UK) are proposing a method for increasing the yield of middle distillates (such as car fuel, jet fuel, and diesel fuel) from the refinery by applying catalytic hydrotreating (HDT) to the full crude oil, rather than the now common application of hydrotreating processes to oil fractions a (i.e., after the separation of crude oil into its fractions, such as gasoline, kerosene, and light and heavy gas oils).
In a study reported in a paper in the ACS journal Energy & Fuels, the team found that their process showed greater yield of desirable middle distillates compared to the yield produced by conventional methods and, consequently, a decrease in the yield of less-desirable reduced crude residue (RCR). They also noted that the specifications of RCR produced by the direct hydrotreating of crude oil are better than the specifications of RCR produced by conventional processes; levels of sulfur, nitrogen, metals, and asphaltene are much lower in comparison to the contents of RCR produced by conventional methods, allowing for the production of good fuel oils.
Free Full Text Source: http://www.greencarcongress.com/2011/01/jarullah-20110115.html
Simulation And Modeling Of Catalytic Reformingprocess
Petroleum & Coal 54 (1) 76-84, 2012
Simulation And Modeling Of Catalytic Reformingprocess
Aboalfazl Askari*, Hajir Karimi, M.Reza Rahimi, Mehdi Ghanbari
aboalfazl_askari@yahoo.com
Chemical engineering department, School of engineering,Yasouj University,Yasouj
Abstract
One of the most important processes in oil refineries is catalytic reforming unit in which high octane gasoline is produced. The catalytic reforming unit by using Hysys-refinery software was simulated. The results are validated by operating data, which is taken from the Esfahan oil refinery catalytic reforming unit.
Usually, in oil refineries, flow instability in composition of feedstock can affect the product quality. The attention of this paper was focused on changes of the final product flow rate and product’s octane number with respect to the changes in the feedstock composition. The results showed that if the feed stream of catalytic reforming unit supplied with the Heavy Isomax Naphtha can be increased, more than 20% of the current value, the flow rate and octane number of the final product will be increased. Also, we found that the variations of temperature and pressure, under operating condition of the reactors of this unit, has no effect on octane number and final product flow rate. Free Full Text Source: http://vurup.sk.tapir.brain.sk/sites/default/files/downloads/pc_1_2012_askari_148.pdf
Simulation And Modeling Of Catalytic Reformingprocess
Aboalfazl Askari*, Hajir Karimi, M.Reza Rahimi, Mehdi Ghanbari
aboalfazl_askari@yahoo.com
Chemical engineering department, School of engineering,Yasouj University,Yasouj
Abstract
One of the most important processes in oil refineries is catalytic reforming unit in which high octane gasoline is produced. The catalytic reforming unit by using Hysys-refinery software was simulated. The results are validated by operating data, which is taken from the Esfahan oil refinery catalytic reforming unit.
Usually, in oil refineries, flow instability in composition of feedstock can affect the product quality. The attention of this paper was focused on changes of the final product flow rate and product’s octane number with respect to the changes in the feedstock composition. The results showed that if the feed stream of catalytic reforming unit supplied with the Heavy Isomax Naphtha can be increased, more than 20% of the current value, the flow rate and octane number of the final product will be increased. Also, we found that the variations of temperature and pressure, under operating condition of the reactors of this unit, has no effect on octane number and final product flow rate. Free Full Text Source: http://vurup.sk.tapir.brain.sk/sites/default/files/downloads/pc_1_2012_askari_148.pdf
Energy Conservation in Heavy-Hydrocabon Distillation
PATENT
Energy Conservation in Heavy-Hydrocabon Distillation
United States Patent Application 20120048711
Inventors:
Werba, Gregory R. (Arlington Heights, IL, US)
Corradi, Jason T. (Arlington Heights, IL, US)
Ablin, David W. (Arlington Heights, IL, US)
Application Number: 12/868223
Publication Date: 03/01/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex.
FIELD OF THE INVENTION
This invention relates to an improved apparatus suitable for energy savings in the distillation of hydrocarbons. More specifically, the present invention concerns an apparatus providing energy conservation within an aromatics-processing complex producing xylene isomers.
BACKGROUND OF THE INVENTION
The xylene isomers are feedstocks for a variety of important industrial chemicals. The most widely produced and used of the xylene isomers is para-xylene, the principal feedstock for polyester, which continues to enjoy a high growth rate from large base demand. Ortho-xylene is used to produce phthalic anhydride, which supplies high-volume but relatively mature markets. Meta-xylene is used in lesser but growing volumes for such products as plasticizers, azo dyes and wood preservers. Ethylbenzene generally is present in xylene mixtures and is occasionally recovered for styrene production, but is usually considered a less-desirable component of C8 aromatics.
Among the aromatic hydrocarbons, the overall importance of xylenes rivals that of benzene as a feedstock for industrial chemicals. Xylenes and benzene are produced from petroleum by reforming naphtha but not in sufficient volume to meet demand, thus conversion of other hydrocarbons is necessary to increase the yield of xylenes and benzene. Often toluene is de-alkylated to produce benzene or selectively disproportionated to yield benzene and C8 aromatics from which the individual xylene isomers are recovered.
An aromatics complex flow scheme has been disclosed by Meyers in the Handbook of Petroleum Refining Processes, 2d. Edition in 1997 by McGraw-Hill, and is incorporated herein by reference.
Aromatics complexes producing xylenes are substantial consumers of energy, notably in distillation operations to prepare feedstocks and separate products from conversion processes. The separation of xylenes from heavy aromatics in particular offers substantial potential for energy savings. Energy conservation in such processes would not only reduce processing costs but also would address current concerns about carbon emissions.
SUMMARY OF THE INVENTION
A broad embodiment of the present invention is a distillation apparatus comprising two distillation columns for separating C8-aromatic components from C9-and-heavier aromatic components, comprising a first distillation column adapted to operate at a first pressure and having a bottom portion in fluid communication with a reboiler, a second distillation column adapted to operate at a second pressure and having a top portion in fluid communication with an overhead conduit, the overhead conduit from the second column providing fluid communication to the reboiler of the first column.
A more specific embodiment is a distillation apparatus comprising two distillation columns for separating C8-aromatic components from C9-and-heavier aromatic components, comprising a first distillation column adapted to operate at a first pressure and having a bottom portion in fluid communication with a reboiler, a second distillation column adapted to operate at a second pressure and having a top portion in fluid communication with an overhead conduit, the overhead conduit from the second column providing fluid communication to the reboiler of the first column and the overhead conduit adapted to supply a heat source to the reboiler.
More preferably, the second pressure is at least 400 kPa higher than the first pressure.
Additional objects, embodiments and details of this invention can be obtained and inferred from the following detailed description of the invention.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0048711.html
Energy Conservation in Heavy-Hydrocabon Distillation
United States Patent Application 20120048711
Inventors:
Werba, Gregory R. (Arlington Heights, IL, US)
Corradi, Jason T. (Arlington Heights, IL, US)
Ablin, David W. (Arlington Heights, IL, US)
Application Number: 12/868223
Publication Date: 03/01/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex.
FIELD OF THE INVENTION
This invention relates to an improved apparatus suitable for energy savings in the distillation of hydrocarbons. More specifically, the present invention concerns an apparatus providing energy conservation within an aromatics-processing complex producing xylene isomers.
BACKGROUND OF THE INVENTION
The xylene isomers are feedstocks for a variety of important industrial chemicals. The most widely produced and used of the xylene isomers is para-xylene, the principal feedstock for polyester, which continues to enjoy a high growth rate from large base demand. Ortho-xylene is used to produce phthalic anhydride, which supplies high-volume but relatively mature markets. Meta-xylene is used in lesser but growing volumes for such products as plasticizers, azo dyes and wood preservers. Ethylbenzene generally is present in xylene mixtures and is occasionally recovered for styrene production, but is usually considered a less-desirable component of C8 aromatics.
Among the aromatic hydrocarbons, the overall importance of xylenes rivals that of benzene as a feedstock for industrial chemicals. Xylenes and benzene are produced from petroleum by reforming naphtha but not in sufficient volume to meet demand, thus conversion of other hydrocarbons is necessary to increase the yield of xylenes and benzene. Often toluene is de-alkylated to produce benzene or selectively disproportionated to yield benzene and C8 aromatics from which the individual xylene isomers are recovered.
An aromatics complex flow scheme has been disclosed by Meyers in the Handbook of Petroleum Refining Processes, 2d. Edition in 1997 by McGraw-Hill, and is incorporated herein by reference.
Aromatics complexes producing xylenes are substantial consumers of energy, notably in distillation operations to prepare feedstocks and separate products from conversion processes. The separation of xylenes from heavy aromatics in particular offers substantial potential for energy savings. Energy conservation in such processes would not only reduce processing costs but also would address current concerns about carbon emissions.
SUMMARY OF THE INVENTION
A broad embodiment of the present invention is a distillation apparatus comprising two distillation columns for separating C8-aromatic components from C9-and-heavier aromatic components, comprising a first distillation column adapted to operate at a first pressure and having a bottom portion in fluid communication with a reboiler, a second distillation column adapted to operate at a second pressure and having a top portion in fluid communication with an overhead conduit, the overhead conduit from the second column providing fluid communication to the reboiler of the first column.
A more specific embodiment is a distillation apparatus comprising two distillation columns for separating C8-aromatic components from C9-and-heavier aromatic components, comprising a first distillation column adapted to operate at a first pressure and having a bottom portion in fluid communication with a reboiler, a second distillation column adapted to operate at a second pressure and having a top portion in fluid communication with an overhead conduit, the overhead conduit from the second column providing fluid communication to the reboiler of the first column and the overhead conduit adapted to supply a heat source to the reboiler.
More preferably, the second pressure is at least 400 kPa higher than the first pressure.
Additional objects, embodiments and details of this invention can be obtained and inferred from the following detailed description of the invention.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0048711.html
Structural and Functional Microbial Ecology of Denitrifying Bacteria Using Different Organic Carbon Sources
THESIS
Structural and Functional Microbial Ecology of Denitrifying Bacteria Using Different Organic Carbon Sources
Huijie Lu
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY, 2011
This dissertation research represents one of the first attempts to investigate the structural and functional microbial ecology of methanol, ethanol and glycerol fostered denitrification. The overarching goal of this research was to elucidate the link between the structure and function of denitrifying microbial populations grown on different carbon sources.
Specific objectives were to:
1) diagnose bacteria specifically assimilating methanol and ethanol and determine denitrification kinetics induced by the two carbon sources;
2) investigate factors leading to nitrous oxide (N2O) and nitric oxide (NO) emissions from methanol and ethanol feeding denitrification reactors;
3) characterize glycerol assimilating populations that perform suspended- and biofilm-growth denitrification;
4) examine the potential of using alcohol dehydrogenase gene as a biomarker for methanol and glycerol induced denitrification activity;
5) evaluate the impact of different carbon sources (methanol and ethanol) on the transcript and proteome of a model facultative methylotroph, Methyloversatilis universalis FAM5.
Free Full Text Source: http://academiccommons.columbia.edu/download/fedora_content/download/ac:141647/CONTENT/Lu_columbia_0054D_10426.pdf
Structural and Functional Microbial Ecology of Denitrifying Bacteria Using Different Organic Carbon Sources
Huijie Lu
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY, 2011
This dissertation research represents one of the first attempts to investigate the structural and functional microbial ecology of methanol, ethanol and glycerol fostered denitrification. The overarching goal of this research was to elucidate the link between the structure and function of denitrifying microbial populations grown on different carbon sources.
Specific objectives were to:
1) diagnose bacteria specifically assimilating methanol and ethanol and determine denitrification kinetics induced by the two carbon sources;
2) investigate factors leading to nitrous oxide (N2O) and nitric oxide (NO) emissions from methanol and ethanol feeding denitrification reactors;
3) characterize glycerol assimilating populations that perform suspended- and biofilm-growth denitrification;
4) examine the potential of using alcohol dehydrogenase gene as a biomarker for methanol and glycerol induced denitrification activity;
5) evaluate the impact of different carbon sources (methanol and ethanol) on the transcript and proteome of a model facultative methylotroph, Methyloversatilis universalis FAM5.
Free Full Text Source: http://academiccommons.columbia.edu/download/fedora_content/download/ac:141647/CONTENT/Lu_columbia_0054D_10426.pdf
The Economic Benefits, Applications And Innovations For Battery-Powered Remote Monitoring
CORROSION 2011, March 13 - 17, 2011 , Houston,
Texas
NACE International
The Economic Benefits, Applications And Innovations For Battery-Powered Remote Monitoring
Craig Held, FreeWave Technologies, Inc.
ABSTRACT
New wireless options have begun to emerge. Battery-powered remote monitoring is a new solution that is available for pipe-to-soil measurement. Unlike a traditional wireless system, this automated remote monitoring system option can be submersed and installed underground.
Battery-powered remote monitoring eliminates the need for manual measurements and provides real-time data from the field directly to the user's fingertips. The remote monitoring option eliminates the need for solar panels. Because it resides underground, it decreases the chance of theft and vandalism.
Full Text Source (Subscription or Fee): http://www.onepetro.org/mslib/servlet/onepetropreview?id=NACE-11048
NACE International
The Economic Benefits, Applications And Innovations For Battery-Powered Remote Monitoring
Craig Held, FreeWave Technologies, Inc.
ABSTRACT
New wireless options have begun to emerge. Battery-powered remote monitoring is a new solution that is available for pipe-to-soil measurement. Unlike a traditional wireless system, this automated remote monitoring system option can be submersed and installed underground.
Battery-powered remote monitoring eliminates the need for manual measurements and provides real-time data from the field directly to the user's fingertips. The remote monitoring option eliminates the need for solar panels. Because it resides underground, it decreases the chance of theft and vandalism.
Full Text Source (Subscription or Fee): http://www.onepetro.org/mslib/servlet/onepetropreview?id=NACE-11048
Applications for Battery-Powered CP Remote Monitoring
NACE International, Vol. 50, No. 5 (May 2011)
Applications for Battery-Powered CP Remote Monitoring
Automated remote monitoring with wireless data communication radios is becoming increasingly popular for many pipeline, energy, and utility operators.
Battery-powered remote monitoring is a new solution that is available for pipe-to-soil measurement. This system can be submersed or installed underground, making it less conspicuous and reducing the chance of damage or vandalism
Free Full Text Source: ftp://ftp.asm-intl.org/uploads/Production/MP_May_2011/nacemp5005p033.pdf
Applications for Battery-Powered CP Remote Monitoring
Automated remote monitoring with wireless data communication radios is becoming increasingly popular for many pipeline, energy, and utility operators.
Battery-powered remote monitoring is a new solution that is available for pipe-to-soil measurement. This system can be submersed or installed underground, making it less conspicuous and reducing the chance of damage or vandalism
Free Full Text Source: ftp://ftp.asm-intl.org/uploads/Production/MP_May_2011/nacemp5005p033.pdf
CO2 capture for refineries, a practical approach
International Journal of Greenhouse Gas Control,
Volume 4, Issue 2, March 2010, Pages 316–320
The Ninth International Conference on Greenhouse Gas Control Technologies
CO2 capture for refineries, a practical approach
Jiri van Straelena,
Frank Geuzebroeka,
Nicholas Goodchildb,
Georgios Protopapasa,
Liam Mahonyc
a Shell Global Solutions, Badhuisweg 3, 1031CM Amsterdam, The Netherlands
b Shell Canada Limited, 400 4th Avenue SW, Station M, Calgary, Alberta T2PH2, 5 Canada
c Shell Global Solutions, Stichthage Building, Koningin Julianaplein 15, 2501 CH The Hague, The Netherlands
Abstract
Evaluates the opportunities and associated costs for post-combustion capture at a world-scale complex refinery.
Results indicate that it is technically feasible to apply post-combustion capture at such a refinery.
However, cost considerations indicate that justification of the implementation of post-combustion capture at refineries requires, either a significant increase in carbon trading values, mandatory regulations, or a major technological break-through.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S175058360900111X
The Ninth International Conference on Greenhouse Gas Control Technologies
CO2 capture for refineries, a practical approach
Jiri van Straelena,
Frank Geuzebroeka,
Nicholas Goodchildb,
Georgios Protopapasa,
Liam Mahonyc
a Shell Global Solutions, Badhuisweg 3, 1031CM Amsterdam, The Netherlands
b Shell Canada Limited, 400 4th Avenue SW, Station M, Calgary, Alberta T2PH2, 5 Canada
c Shell Global Solutions, Stichthage Building, Koningin Julianaplein 15, 2501 CH The Hague, The Netherlands
Abstract
Evaluates the opportunities and associated costs for post-combustion capture at a world-scale complex refinery.
Results indicate that it is technically feasible to apply post-combustion capture at such a refinery.
However, cost considerations indicate that justification of the implementation of post-combustion capture at refineries requires, either a significant increase in carbon trading values, mandatory regulations, or a major technological break-through.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S175058360900111X
Adsorbent For Feed And Products Purification In Benzene Saturation Process
PATENT
Adsorbent For Feed And Products Purification In Benzene Saturation Process
United States Patent Application 20120004480
Inventors:
Kanazirev, Vladislav I. (Arlington Heights, IL, US)
Gorawara, Jayant K. (Buffalo Grove, IL, US)
Sullivan, Dana K. (Mount Prospect, IL, US)
Rosin, Richard R. (Glencoe, IL, US)
Application Number: 13/151449
Publication Date:01/05/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
The service life and deactivation rate of a benzene saturation catalyst is improved through use of a new sulfur guard bed containing a chloride additive. This sulfur guard bed, which contains supported CuO material having an increased resistance to reduction, shows such improvement. Thus, the danger of run-away reduction followed by a massive release of water and deactivation of an isomerization catalyst is practically eliminated. The fact that the guard bed material preserves the active metal phase-copper in an active (oxide) form is an important advantage leading to very low sulfur content in the product stream. The sulfur capacity per unit weight of sorbent is also significantly increased, making this sorbent a superior cost effective sulfur guard product. The guard bed is effective in treating mixed phase feed streams.
BACKGROUND OF THE INVENTION
The present invention involves an improvement to the feed and product in a benzene saturation process. In particular the present invention provides an adsorbent that is effective for trace sulfur removal for feeds that comprise a mixture of phases to benzene saturation units as well as product streams to such units.
For most refiners, the issue of benzene in the gasoline pool is one of managing benzene production from the catalytic reformer. The two primary strategies to accomplish this goal include the minimization of benzene and benzene precursors in the catalytic reformer feed, or the elimination of the benzene from the reformate after it is formed. A benzene saturation unit can be applied in either of these strategies. For example, a benzene saturation unit can be located on the overhead stream of a naphtha splitter, to remove the natural benzene concentrated by aggressive reformer feed prefractionation. Alternatively, a benzene saturation unit can be used on a light reformate stream to remove the benzene that has been produced in the reformer.
The benzene saturation process was developed as a low-cost, stand-alone option to treat C5-C6 feedstocks that are high in benzene. Benzene is saturated with hydrogen to make C6 naphthenes. The catalyst used in this process is highly selective for benzene saturation to C6 naphthenes. Makeup hydrogen is provided in an amount slightly above the stoichiometric level required for benzene saturation. The heat of reaction associated with benzene saturation is carefully managed to control the temperature rise across the reactor. Use of a relatively high space velocity in the reactor contributes to the unit's cost-effectiveness. A benzene saturation unit can be located on a light reformate or light straight-run naphtha stream.
The operation of a benzene saturation unit is very sensitive to the presence of sulfur-containing compounds. The specification and catalyst sensitivity requires extremely low levels of sulfur with preferably less than 50 parts per billion weight of sulfur. It has been found that copper oxides are more effective than other oxides such as zinc oxide and nickel oxide in removing sulfur. Prior art copper oxides had the disadvantage of being reduced to copper metal during operation. This not only decreased their effectiveness in removing sulfur compounds, but since the reduction process is highly exothermic, when used in connection with gases that have a low specific heat, the temperature exotherm can result in unsafe conditions, especially on start-up.
In a prior art design for a benzene saturation unit there has been a separate sulfur guard bed on the naphtha feed, and if warranted by the sulfur content, a second one on the makeup hydrogen stream as well. Separate guard beds have been required due to previous sulfur adsorbents needing to operate in single phase, either vapor or liquid, to achieve the required outlet sulfur level. If a sulfur adsorbent could achieve the required degree of sulfur removal in a mixed phase stream comprising vapor and liquid, it would be possible to instead have a compound bed, with the sulfur adsorbent on top, and the Pt on alumina benzene saturation catalyst below it. This would save capital cost as no separate sulfur guard beds or the related heat exchangers would be needed.
Guard beds with supported copper oxide (CuO) are often used for feed purification in benzene saturation units. Unfortunately, the CuO reduces to a lower valence state, at the typical operating temperatures in the range of ambient temperature for a make-up hydrogen treater and 120° to 150° C. for liquids being treated. Typically in prior art systems, the reduction of CuO occurs rapidly, and large amounts of water are produced. The excessive moisture is disadvantageous to the operation of the benzene saturation catalyst. In addition, there is the undesired exotherm.
Copper containing materials are widely used in industry as catalysts and sorbents. The water shift reaction in which carbon monoxide is reacted in presence of steam to make carbon dioxide and hydrogen as well as the synthesis of methanol and higher alcohols are among the most practiced catalytic processes nowadays. Both processes employ copper oxide based mixed oxide catalysts.
Copper-containing sorbents play a major role in the removal of contaminants, such as sulfur compounds and metal hydrides, from gas and liquid streams. One new use for such sorbents involve the on-board reforming of gasoline to produce hydrogen for polymer electrolyte fuel cells (PEFC). The hydrogen feed to a PEFC must be purified to less than 50 parts per billion parts volume of hydrogen sulfide due to the deleterious effects to the fuel cell of exposure to sulfur compounds.
Copper oxide (CuO) normally is subject to reduction reactions upon being heated but it also can be reduced even at ambient temperatures in ultraviolet light or in the presence of photochemically generated atomic hydrogen.
The use of CuO on a support that can be reduced at relatively low temperatures is considered to be an asset for some applications where it is important to preserve high dispersion of the copper metal. According to U.S. Pat. No. 4,863,894, highly dispersed copper metal particles are produced when co-precipitated copper-zinc-aluminum basic carbonates are reduced with molecular hydrogen without preliminary heating of the carbonates to temperatures above 200° C. to produce the mixed oxides. However, easily reducible CuO is disadvantageous in some important applications, such as the removal of hydrogen sulfide from gas and liquid streams when very low residual concentration of H2S in the product is required
The residual H25 concentration in the product gas is much higher by the laws of thermodynamics (which is undesirable) when the CuO reduces to Cu metal. in the course of the process since reaction (1) is less favored than the CuO sulfidation to CuS.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0004480.html
Adsorbent For Feed And Products Purification In Benzene Saturation Process
United States Patent Application 20120004480
Inventors:
Kanazirev, Vladislav I. (Arlington Heights, IL, US)
Gorawara, Jayant K. (Buffalo Grove, IL, US)
Sullivan, Dana K. (Mount Prospect, IL, US)
Rosin, Richard R. (Glencoe, IL, US)
Application Number: 13/151449
Publication Date:01/05/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
The service life and deactivation rate of a benzene saturation catalyst is improved through use of a new sulfur guard bed containing a chloride additive. This sulfur guard bed, which contains supported CuO material having an increased resistance to reduction, shows such improvement. Thus, the danger of run-away reduction followed by a massive release of water and deactivation of an isomerization catalyst is practically eliminated. The fact that the guard bed material preserves the active metal phase-copper in an active (oxide) form is an important advantage leading to very low sulfur content in the product stream. The sulfur capacity per unit weight of sorbent is also significantly increased, making this sorbent a superior cost effective sulfur guard product. The guard bed is effective in treating mixed phase feed streams.
BACKGROUND OF THE INVENTION
The present invention involves an improvement to the feed and product in a benzene saturation process. In particular the present invention provides an adsorbent that is effective for trace sulfur removal for feeds that comprise a mixture of phases to benzene saturation units as well as product streams to such units.
For most refiners, the issue of benzene in the gasoline pool is one of managing benzene production from the catalytic reformer. The two primary strategies to accomplish this goal include the minimization of benzene and benzene precursors in the catalytic reformer feed, or the elimination of the benzene from the reformate after it is formed. A benzene saturation unit can be applied in either of these strategies. For example, a benzene saturation unit can be located on the overhead stream of a naphtha splitter, to remove the natural benzene concentrated by aggressive reformer feed prefractionation. Alternatively, a benzene saturation unit can be used on a light reformate stream to remove the benzene that has been produced in the reformer.
The benzene saturation process was developed as a low-cost, stand-alone option to treat C5-C6 feedstocks that are high in benzene. Benzene is saturated with hydrogen to make C6 naphthenes. The catalyst used in this process is highly selective for benzene saturation to C6 naphthenes. Makeup hydrogen is provided in an amount slightly above the stoichiometric level required for benzene saturation. The heat of reaction associated with benzene saturation is carefully managed to control the temperature rise across the reactor. Use of a relatively high space velocity in the reactor contributes to the unit's cost-effectiveness. A benzene saturation unit can be located on a light reformate or light straight-run naphtha stream.
The operation of a benzene saturation unit is very sensitive to the presence of sulfur-containing compounds. The specification and catalyst sensitivity requires extremely low levels of sulfur with preferably less than 50 parts per billion weight of sulfur. It has been found that copper oxides are more effective than other oxides such as zinc oxide and nickel oxide in removing sulfur. Prior art copper oxides had the disadvantage of being reduced to copper metal during operation. This not only decreased their effectiveness in removing sulfur compounds, but since the reduction process is highly exothermic, when used in connection with gases that have a low specific heat, the temperature exotherm can result in unsafe conditions, especially on start-up.
In a prior art design for a benzene saturation unit there has been a separate sulfur guard bed on the naphtha feed, and if warranted by the sulfur content, a second one on the makeup hydrogen stream as well. Separate guard beds have been required due to previous sulfur adsorbents needing to operate in single phase, either vapor or liquid, to achieve the required outlet sulfur level. If a sulfur adsorbent could achieve the required degree of sulfur removal in a mixed phase stream comprising vapor and liquid, it would be possible to instead have a compound bed, with the sulfur adsorbent on top, and the Pt on alumina benzene saturation catalyst below it. This would save capital cost as no separate sulfur guard beds or the related heat exchangers would be needed.
Guard beds with supported copper oxide (CuO) are often used for feed purification in benzene saturation units. Unfortunately, the CuO reduces to a lower valence state, at the typical operating temperatures in the range of ambient temperature for a make-up hydrogen treater and 120° to 150° C. for liquids being treated. Typically in prior art systems, the reduction of CuO occurs rapidly, and large amounts of water are produced. The excessive moisture is disadvantageous to the operation of the benzene saturation catalyst. In addition, there is the undesired exotherm.
Copper containing materials are widely used in industry as catalysts and sorbents. The water shift reaction in which carbon monoxide is reacted in presence of steam to make carbon dioxide and hydrogen as well as the synthesis of methanol and higher alcohols are among the most practiced catalytic processes nowadays. Both processes employ copper oxide based mixed oxide catalysts.
Copper-containing sorbents play a major role in the removal of contaminants, such as sulfur compounds and metal hydrides, from gas and liquid streams. One new use for such sorbents involve the on-board reforming of gasoline to produce hydrogen for polymer electrolyte fuel cells (PEFC). The hydrogen feed to a PEFC must be purified to less than 50 parts per billion parts volume of hydrogen sulfide due to the deleterious effects to the fuel cell of exposure to sulfur compounds.
Copper oxide (CuO) normally is subject to reduction reactions upon being heated but it also can be reduced even at ambient temperatures in ultraviolet light or in the presence of photochemically generated atomic hydrogen.
The use of CuO on a support that can be reduced at relatively low temperatures is considered to be an asset for some applications where it is important to preserve high dispersion of the copper metal. According to U.S. Pat. No. 4,863,894, highly dispersed copper metal particles are produced when co-precipitated copper-zinc-aluminum basic carbonates are reduced with molecular hydrogen without preliminary heating of the carbonates to temperatures above 200° C. to produce the mixed oxides. However, easily reducible CuO is disadvantageous in some important applications, such as the removal of hydrogen sulfide from gas and liquid streams when very low residual concentration of H2S in the product is required
The residual H25 concentration in the product gas is much higher by the laws of thermodynamics (which is undesirable) when the CuO reduces to Cu metal. in the course of the process since reaction (1) is less favored than the CuO sulfidation to CuS.
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Separation Of Aromatics With Pervaporation Membrane
PATENT
Separation Of Aromatics With Pervaporation Membrane
United States Patent Application 20120074043
Inventors:
Kalakkunnath, Sumod (Bartlesville, OK, US)
Anderson, Richard L. (Bartlesville, OK, US)
Anderson, James A. (Prud'homme, CA)
Sadok, Richard D. (Bartlesville, OK, US)
Karpe, Prakash A. (Walnut Creek, CA, US)
Application Number: 13/238974
Publication Date:03/29/2012 Filing Date:09/21/2011
Assignee: CONOCOPHILLIPS COMPANY (Houston, TX, US)
Abstract:
Methods and apparatus relate to separating and removing aromatic compounds from a hydrocarbon stream. Splitting of the hydrocarbon stream into constituents as desired relies on a membrane and distillation columns that supply feed into the membrane and receive retentate and permeate streams output from the membrane. Configurations employing the membrane and the distillation columns enable benzene recovery and facilitate efficient separation.
FIELD OF THE INVENTION
Embodiments of the invention relate to splitting of aromatic-containing streams based on constituents therein.
BACKGROUND OF THE INVENTION
Petroleum refineries produce hydrocarbon streams that contain aromatics such as benzene. However, government regulations limit quantity of the benzene in products including gasoline. Benzene content comes from both synthesis of the benzene during refining and natural occurrence of the benzene in production.
Techniques used to reduce amount of the benzene synthesized fail to provide the benzene content as low as desired. Therefore, benzene, toluene, and xylene (BTX) splitters provide for removal of the benzene, which may then be converted or used as an intermediary to make other chemicals. Commercial application of any process associated with recovery of the benzene depends on costs. Prior BTX splitters utilize procedures with undesirable costs due to being complex, energy intensive and capital intensive.
Therefore, a need exists for methods and systems for splitting of aromatic-containing streams based on constituents therein.
BRIEF SUMMARY OF THE DISCLOSURE
In one embodiment, a method includes passing a hydrocarbon stream through a first distillation column to separate a first fraction containing aromatics from a second fraction and passing the first fraction through a membrane unit to generate a retentate stream and a permeate stream with higher benzene content than the retentate stream. Passing the retentate stream through a second distillation column provides first fractionated outputs with one further concentrated in toluene relative to the retentate stream. Further, passing the permeate stream through a third distillation column provides second fractionated outputs with one further concentrated in benzene relative to the permeate stream.
According to one embodiment, a method includes passing a hydrocarbon stream through a first distillation column to separate a top fraction containing aromatics from a bottom fraction and passing the top fraction through a membrane unit to generate a retentate stream and a permeate stream with higher benzene content than the retentate stream. The method further includes passing the retentate stream through a second distillation column for overhead removal of benzene such that remaining output of the second distillation column is further concentrated in toluene relative to the retentate stream. In addition, the method includes passing the permeate stream through a third distillation column for overhead removal of components lighter than benzene such that remaining output of the third distillation column is further concentrated in benzene relative to the permeate stream.
For one embodiment, a method includes passing a hydrocarbon stream through a first distillation column to separate a bottom fraction containing aromatics from a top fraction and passing the bottom fraction through a membrane unit to generate a retentate stream and a permeate stream with higher benzene content than the retentate stream. The method also includes passing the retentate stream through a second distillation column for overhead removal of toluene concentrated relative to the retentate stream due to separation from remaining output of the second distillation column. Further, the method includes passing the permeate stream through a third distillation column for overhead removal of benzene concentrated relative to the permeate stream due to separation from remaining output of the second distillation column.
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Separation Of Aromatics With Pervaporation Membrane
United States Patent Application 20120074043
Inventors:
Kalakkunnath, Sumod (Bartlesville, OK, US)
Anderson, Richard L. (Bartlesville, OK, US)
Anderson, James A. (Prud'homme, CA)
Sadok, Richard D. (Bartlesville, OK, US)
Karpe, Prakash A. (Walnut Creek, CA, US)
Application Number: 13/238974
Publication Date:03/29/2012 Filing Date:09/21/2011
Assignee: CONOCOPHILLIPS COMPANY (Houston, TX, US)
Abstract:
Methods and apparatus relate to separating and removing aromatic compounds from a hydrocarbon stream. Splitting of the hydrocarbon stream into constituents as desired relies on a membrane and distillation columns that supply feed into the membrane and receive retentate and permeate streams output from the membrane. Configurations employing the membrane and the distillation columns enable benzene recovery and facilitate efficient separation.
FIELD OF THE INVENTION
Embodiments of the invention relate to splitting of aromatic-containing streams based on constituents therein.
BACKGROUND OF THE INVENTION
Petroleum refineries produce hydrocarbon streams that contain aromatics such as benzene. However, government regulations limit quantity of the benzene in products including gasoline. Benzene content comes from both synthesis of the benzene during refining and natural occurrence of the benzene in production.
Techniques used to reduce amount of the benzene synthesized fail to provide the benzene content as low as desired. Therefore, benzene, toluene, and xylene (BTX) splitters provide for removal of the benzene, which may then be converted or used as an intermediary to make other chemicals. Commercial application of any process associated with recovery of the benzene depends on costs. Prior BTX splitters utilize procedures with undesirable costs due to being complex, energy intensive and capital intensive.
Therefore, a need exists for methods and systems for splitting of aromatic-containing streams based on constituents therein.
BRIEF SUMMARY OF THE DISCLOSURE
In one embodiment, a method includes passing a hydrocarbon stream through a first distillation column to separate a first fraction containing aromatics from a second fraction and passing the first fraction through a membrane unit to generate a retentate stream and a permeate stream with higher benzene content than the retentate stream. Passing the retentate stream through a second distillation column provides first fractionated outputs with one further concentrated in toluene relative to the retentate stream. Further, passing the permeate stream through a third distillation column provides second fractionated outputs with one further concentrated in benzene relative to the permeate stream.
According to one embodiment, a method includes passing a hydrocarbon stream through a first distillation column to separate a top fraction containing aromatics from a bottom fraction and passing the top fraction through a membrane unit to generate a retentate stream and a permeate stream with higher benzene content than the retentate stream. The method further includes passing the retentate stream through a second distillation column for overhead removal of benzene such that remaining output of the second distillation column is further concentrated in toluene relative to the retentate stream. In addition, the method includes passing the permeate stream through a third distillation column for overhead removal of components lighter than benzene such that remaining output of the third distillation column is further concentrated in benzene relative to the permeate stream.
For one embodiment, a method includes passing a hydrocarbon stream through a first distillation column to separate a bottom fraction containing aromatics from a top fraction and passing the bottom fraction through a membrane unit to generate a retentate stream and a permeate stream with higher benzene content than the retentate stream. The method also includes passing the retentate stream through a second distillation column for overhead removal of toluene concentrated relative to the retentate stream due to separation from remaining output of the second distillation column. Further, the method includes passing the permeate stream through a third distillation column for overhead removal of benzene concentrated relative to the permeate stream due to separation from remaining output of the second distillation column.
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Processes For Increasing The Overall Aromatics And Xylenes Yield In An Aromatics Complex
PATENT
Processes For Increasing The Overall Aromatics And Xylenes Yield In An Aromatics Complex
United States Patent Application 20120067774
Inventors:
Frey, Stanley J. (Palatine, IL, US)
Corradi, Jason T. (Arlington Heights, IL, US)
Werba, Gregory (Arlington Heights, IL, US)
Application Number: 12/883977
Publication Date:03/22/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
Processes for increasing overall aromatics and xylenes yield in an aromatics complex are provided. A C8+ aromatics stream from an aromatics-rich reformate is separated into a C8 aromatics fraction and a C9+ aromatics fraction comprising higher alkyl group-substituted C9 and C10 aromatics. The C9+ aromatics fraction is separated into a lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction and a heavier boiling, C10+ or C11+ aromatics fraction. The lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction is isomerized to convert a portion of the higher alkyl group-substituted C9 or C9/C10 aromatics therein into methyl-enriched C9 aromatics or methyl-enriched C9/C10 aromatics. The methyl-enriched C9+ aromatics stream comprising the methyl-enriched C9+ aromatics stream or the methyl-enriched C9/C10 aromatics is transalkylated with a toluene-containing stream.
FIELD OF THE INVENTION
The present invention generally relates to aromatics production, and more particularly relates to processes for increasing the overall aromatics and xylenes yield in an aromatics complex.
DESCRIPTION OF RELATED ART
An aromatics complex is a combination of process units that are used to convert naphtha, from a variety of sources, and pyrolysis gasoline into the basic petrochemical intermediates, benzene, toluene, and mixed xylenes. In aromatics applications, the naphtha is generally restricted to C6+ compounds to maximize the production of benzene, toluene, and xylenes. The majority of the mixed xylenes are processed further within the aromatics complex, in a xylenes recovery section, to produce one or more individual aromatic isomers. As used herein, “mixed xylenes” contain four different C8 aromatic isomers, including para-xylene which is used for the production of polyester fibers, resins and films.
Additional mixed xylenes may be produced from toluene, which is of low value, and heavy aromatics (C9+ aromatics) (also referred to hereinafter as “heavies”) that are present in reformate from the naphtha feedstock. Reformate is produced by selectively reforming the naphtha feedstock, in the presence of a reforming catalyst, to aromatics and high purity hydrogen. The naphtha feedstock is first hydrotreated to remove sulfur and nitrogen compounds and then sent to a reforming unit. In the reforming unit, paraffins and naphthenes in the naphtha feedstock are converted to aromatics, with as little aromatic ring opening or cracking as possible, producing “catalytically reformed naphtha”.
To produce additional mixed xylenes from the low-value toluene and heavy aromatics (C9+ aromatics), the aromatics complex may include a transalkylation process unit that is integrated between an aromatics fractionation section and the xylenes recovery section of the aromatics complex. The two major reactions in the transalkylation process unit are disproportionation and transalkylation. The conversion of toluene into benzene and mixed xylenes is called toluene disproportionation. Transalkylation is the conversion of a mixture of toluene, C9 aromatics (A9s), and C10 aromatics (A10s) into benzene and mixed xylenes. The process reactions are conducted in a hydrogen atmosphere to minimize coke formation on a transalkylation catalyst. As there is negligible aromatic ring destruction during the process, there is very little hydrogen consumption as a result of these reactions.
The catalytically reformed naphtha and pyrolysis gasoline feedstocks contain a large amount of phenyl groups substituted with ethyl, propyl, and butyl groups (collectively referred to herein as “higher alkyl groups”). Unfortunately, alkyl groups larger than methyl are cracked off of the phenyl group during transalkylation. “Dealkylation” refers to the complete or partial removal of the alkyl group(s). The scission of these higher alkyl groups leads to higher fuel gas yield, and higher benzene rather than more valuable para-xylene yield relative to the equivalent carbon number aromatic that had greater methyl group substitution. In addition, most of the hydrogen that is consumed during disproportionation and transalkylation is attributable to the cracking of non-aromatic impurities in the feedstock and such dealkylation of the ethyl, propyl, and butyl groups from the C9 and C10 aromatics.
Accordingly, it is desirable to provide processes for increasing overall aromatics and xylenes yield in an aromatics complex. It is also desirable to provide processes that increase the overall aromatics and xylenes yield in an aromatics complex that also reduce the amount of mass lost to fuel gas, and that shift the chemical equilibrium from benzene production to xylenes production while consuming less hydrogen. It is additionally desirable to provide processes for increasing overall aromatics and xylenes yield, while increasing conversion of toluene into mixed xylenes. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.
SUMMARY OF THE INVENTION
Processes are provided for increasing overall aromatics and xylenes yield in an aromatics complex. In accordance with one exemplary embodiment, the process comprises separating a C8+ aromatics stream from an aromatics-rich reformate, into a C8 aromatics fraction and a C9+ aromatics fraction comprising higher alkyl group-substituted C9 and C10 aromatics. The C9+ aromatics fraction is separated into a lighter boiling, higher alkyl-substituted C9 or C9/C10 aromatics fraction and a heavier boiling, C10+ or C11+ aromatics fraction. The lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction are isomerized to convert a portion of the higher alkyl group-substituted C9 or C9/C10 aromatics therein into methyl-enriched C9 or C9/C10 aromatics. The methyl-enriched C9+ stream with the heavier boiling, C10+ aromatics fraction. The methyl-enriched C9+ aromatics stream comprising the methyl-enriched C9 aromatics or the methyl-enriched C9/C10 aromatics are transalkylated.
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Processes For Increasing The Overall Aromatics And Xylenes Yield In An Aromatics Complex
United States Patent Application 20120067774
Inventors:
Frey, Stanley J. (Palatine, IL, US)
Corradi, Jason T. (Arlington Heights, IL, US)
Werba, Gregory (Arlington Heights, IL, US)
Application Number: 12/883977
Publication Date:03/22/2012
Assignee: UOP LLC (Des Plaines, IL, US)
Abstract:
Processes for increasing overall aromatics and xylenes yield in an aromatics complex are provided. A C8+ aromatics stream from an aromatics-rich reformate is separated into a C8 aromatics fraction and a C9+ aromatics fraction comprising higher alkyl group-substituted C9 and C10 aromatics. The C9+ aromatics fraction is separated into a lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction and a heavier boiling, C10+ or C11+ aromatics fraction. The lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction is isomerized to convert a portion of the higher alkyl group-substituted C9 or C9/C10 aromatics therein into methyl-enriched C9 aromatics or methyl-enriched C9/C10 aromatics. The methyl-enriched C9+ aromatics stream comprising the methyl-enriched C9+ aromatics stream or the methyl-enriched C9/C10 aromatics is transalkylated with a toluene-containing stream.
FIELD OF THE INVENTION
The present invention generally relates to aromatics production, and more particularly relates to processes for increasing the overall aromatics and xylenes yield in an aromatics complex.
DESCRIPTION OF RELATED ART
An aromatics complex is a combination of process units that are used to convert naphtha, from a variety of sources, and pyrolysis gasoline into the basic petrochemical intermediates, benzene, toluene, and mixed xylenes. In aromatics applications, the naphtha is generally restricted to C6+ compounds to maximize the production of benzene, toluene, and xylenes. The majority of the mixed xylenes are processed further within the aromatics complex, in a xylenes recovery section, to produce one or more individual aromatic isomers. As used herein, “mixed xylenes” contain four different C8 aromatic isomers, including para-xylene which is used for the production of polyester fibers, resins and films.
Additional mixed xylenes may be produced from toluene, which is of low value, and heavy aromatics (C9+ aromatics) (also referred to hereinafter as “heavies”) that are present in reformate from the naphtha feedstock. Reformate is produced by selectively reforming the naphtha feedstock, in the presence of a reforming catalyst, to aromatics and high purity hydrogen. The naphtha feedstock is first hydrotreated to remove sulfur and nitrogen compounds and then sent to a reforming unit. In the reforming unit, paraffins and naphthenes in the naphtha feedstock are converted to aromatics, with as little aromatic ring opening or cracking as possible, producing “catalytically reformed naphtha”.
To produce additional mixed xylenes from the low-value toluene and heavy aromatics (C9+ aromatics), the aromatics complex may include a transalkylation process unit that is integrated between an aromatics fractionation section and the xylenes recovery section of the aromatics complex. The two major reactions in the transalkylation process unit are disproportionation and transalkylation. The conversion of toluene into benzene and mixed xylenes is called toluene disproportionation. Transalkylation is the conversion of a mixture of toluene, C9 aromatics (A9s), and C10 aromatics (A10s) into benzene and mixed xylenes. The process reactions are conducted in a hydrogen atmosphere to minimize coke formation on a transalkylation catalyst. As there is negligible aromatic ring destruction during the process, there is very little hydrogen consumption as a result of these reactions.
The catalytically reformed naphtha and pyrolysis gasoline feedstocks contain a large amount of phenyl groups substituted with ethyl, propyl, and butyl groups (collectively referred to herein as “higher alkyl groups”). Unfortunately, alkyl groups larger than methyl are cracked off of the phenyl group during transalkylation. “Dealkylation” refers to the complete or partial removal of the alkyl group(s). The scission of these higher alkyl groups leads to higher fuel gas yield, and higher benzene rather than more valuable para-xylene yield relative to the equivalent carbon number aromatic that had greater methyl group substitution. In addition, most of the hydrogen that is consumed during disproportionation and transalkylation is attributable to the cracking of non-aromatic impurities in the feedstock and such dealkylation of the ethyl, propyl, and butyl groups from the C9 and C10 aromatics.
Accordingly, it is desirable to provide processes for increasing overall aromatics and xylenes yield in an aromatics complex. It is also desirable to provide processes that increase the overall aromatics and xylenes yield in an aromatics complex that also reduce the amount of mass lost to fuel gas, and that shift the chemical equilibrium from benzene production to xylenes production while consuming less hydrogen. It is additionally desirable to provide processes for increasing overall aromatics and xylenes yield, while increasing conversion of toluene into mixed xylenes. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.
SUMMARY OF THE INVENTION
Processes are provided for increasing overall aromatics and xylenes yield in an aromatics complex. In accordance with one exemplary embodiment, the process comprises separating a C8+ aromatics stream from an aromatics-rich reformate, into a C8 aromatics fraction and a C9+ aromatics fraction comprising higher alkyl group-substituted C9 and C10 aromatics. The C9+ aromatics fraction is separated into a lighter boiling, higher alkyl-substituted C9 or C9/C10 aromatics fraction and a heavier boiling, C10+ or C11+ aromatics fraction. The lighter boiling, higher alkyl group-substituted C9 or C9/C10 aromatics fraction are isomerized to convert a portion of the higher alkyl group-substituted C9 or C9/C10 aromatics therein into methyl-enriched C9 or C9/C10 aromatics. The methyl-enriched C9+ stream with the heavier boiling, C10+ aromatics fraction. The methyl-enriched C9+ aromatics stream comprising the methyl-enriched C9 aromatics or the methyl-enriched C9/C10 aromatics are transalkylated.
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Process For The Recovery Of Pure Aromatics From Hydrocarbon Fractions Containing Aromatics
PATENT
Process For The Recovery Of Pure Aromatics From Hydrocarbon Fractions Containing Aromatics
United States Patent Application 20120067776
Inventors:
Diehl, Thomas (Frankfurt, DE)
Gehrke, Helmut (Bergkamen, DE)
Kolbe, Baerbel (Witten, DE)
Wilken, Dieter (Oelde, DE)
Application Number: 13/138587
Publication Date:03/22/2012
Assignee: UHDE GMBH (Dortmund, DE)
Abstract:
A process for the recovery of a pure aromatics-containing product is disclosed. This product is obtained by extractive distillation of a gasoline rich in aromatics, in which olefins, diolefins and polyolefins are separated, and this extractive distillation is followed by a hydrogenation of the recovered aromatics-rich, olefin-lean product stream, in which the alkylated aromatics, especially toluene and xylene, are dealkylated and the paraffinic dealkylation products further converted into methane so that a significant portion of hydrogen can be saved by carrying out the hydrogenation subsequent to the extractive distillation, as the aromatics mixture is then free of olefins and no hydrogen is required for an olefin hydrogenation, with extractive distillation and recovery of the extracting solvent taking place in one column. An apparatus for carrying out the process described is also disclosed. A column is preferably used for the extractive distillation which allows performing the extractive distillation with a solvent recycling system so that it is not required to provide an additional stripping column for removing the extracting solvent.
Description:The invention relates to a process for the recovery of pure aromatics from aromatics-containing hydrocarbon fractions and, in particular, from reformate gasoline, from fully hydrogenated pyrolysis gasoline, from coke-oven light oil refined under pressure or from mixtures thereof. The process according to the invention serves to provide aromatics and especially benzene, the alkylated benzene derivatives of the aromatics factions being converted by hydrodealkylation to give benzene or lower alkylated benzene derivatives. Depending on the design of the process high-purity products can be produced. By a novel process configuration it is possible to achieve a significant saving in expensive hydrogen used for the hydrodealkylation and in technical equipment. The invention also relates to an apparatus which serves to carry out this process.
Aromatics, particularly benzene, toluene and xylenes are important feedstocks used in the chemical industry, especially for the production of plastics and man-made fibres. In addition, aromatics are used to boost the octane number of Otto fuel. For the chemical industry application it is favourable to provide the required aromatics in the form of pure benzene as the demand for this chemical is especially high.
To recover benzene by hydrodealkylation, reformate gasoline, fully hydrogenated pyrolysis gasoline, coke-oven light oil refined under pressure or mixtures thereof may be used as hydrocarbon mixtures rich in aromatics. These feed products or mixtures thereof are hereinafter referred to as gasoline fractions. The used gasoline fractions contain major amounts of benzene derivatives, especially alkylaromatics. These can be converted by thermal or catalytic hydrogenation to give benzene, in which the alkyl substituents of the benzene are released and fully hydrogenated by reaction with hydrogen. This process of hydrodealkylation (“HDA”) serves to obtain the required benzene. Apart from the required benzene, the alkyl substituents are obtained in the form of alkanes.
The reformate gasoline is a benzene rich in aromatics, which is produced by reforming and especially catalytic reforming of naphtha. During the reforming process, the alkanes and cycloalkanes contained in the petroleum or crude oil are subject to isomerizations, rearrangements, cyclizations, dehydrogenations and similar reactions. The aromatics-rich reformate gasoline obtained from catalytic reforming serves as an important feedstock in the recovery of aromatics.
The fully hydrogenated pyrolysis gasoline is a gasoline rich in aromatics which is obtained from steam cracking of hydrocarbons. Steam cracking of hydrocarbons mainly serves to generate lower olefins, especially ethene. Depending on the boiling range of the hydrocarbon mixture used for steam cracking, a large amount of a by-product rich in aromatics is obtained, the so-called pyrolysis gasoline, which, for further processing, is yet to be freed from unsaturated compounds and hetero-atoms (sulphur, nitrogen, oxygen) in various hydrogenation steps (selective hydrogenation, full hydrogenation). The product obtained from the hydrogenation steps is an aromatics-rich fraction which is referred to as a fully hydrogenated pyrolysis gasoline.
The coke-oven light oil refined under pressure is also a product rich in aromatics. Coke-oven crude light oil is obtained from the coking of coal. Similar to the pyrolysis gasoline, this coke-oven crude light oil still contains unsaturated compounds and hetero-atomic compounds apart from aromatics. Similar to the treatment of the pyrolysis gasoline, the coke-oven crude light oil is also hydrogenated to convert the unsaturated compounds as well as the hetero-atomic compounds. One of the products of this conversion is an aromatics-rich product which is free of unsaturated compounds and hetero-atomic compounds and can be used in a subsequent process. This aromatics-rich product is also referred to as coke-oven light oil refined under pressure.
The aromatics-rich hydrocarbon mixtures used may contain major amounts of non-aromatic compounds such as especially paraffins and naphthenes or olefins which are also hydrogenated in the hydrodealkylation giving alkane as hydrogenation product. If the hydrogenation is continued, methane is obtained from the cracking of alkanes. Depending on the stoichiometric amount of hydrogen used, the hydrodealkylation can also give lower alkylated benzene derivatives which have not been dealkylated completely to benzene.
The presence of large amounts of non-aromatic compounds in the feed stream to the hydrodealkylation requires an adequately large amount of hydrogen to carry out the reaction since hydrogen is not only required to dealkylate the alkylaromatics by hydrogenation to give benzene or lower alkylated benzene derivatives but also to decompose the longer chain non-aromatic compounds to short chain non-aromatic compounds. If the longer chain compounds are decomposed completely, methane is obtained. Therefore it is an aim of the invention to provide a process for the hydrodealkylation which minimises the use of hydrogen.
Apart from the required benzene, the hydrodealkylation also gives a mixture of short-chain paraffins and/or methane. The amount of gas generated by the dealkylation of aromatics cannot be influenced by the process according to the invention. It is, however, also the aim of this invention to reduce the amount of gas generated by the hydrogenation of the non-aromatic compounds also entrained in the feed stream.
To achieve these aims it is advantageous to first purify the hydrocarbon fraction to be submitted to hydrodealkylation in an extractive distillation. By carrying out the extractive distillation it is possible to separate a major part of the non-aromatic compounds already. The aromatics concentrate obtained from the extractive distillation can then be passed to a hydrodealkylation. As no hydrogen is consumed by the chain-shortening hydrogenation of the non-aromatic compounds which have already been removed from the starting mixture by an extractive distillation, a reduction in the amount of hydrogen consumed by the hydrodealkylation is achieved. In addition, the substance mixture contains lower portions of gaseous paraffins owing to the upstream installation of the extractive distillation after the hydrodealkylation. In this way it is possible to design the whole process for a lower gas flow rate which is of advantageous effect.
EP 792928 B1 describes a process for the recovery of pure aromatics from reformate gasoline. The teaching discloses a process in which, in a first process step, a reformate cut with aromatics of a selected carbon number or with aromatics of several selected carbon numbers Cx, Cy is recovered from the reformate gasoline by fractionating distillation and the aromatics cut is hydrogenated selectively via a hydrogenating catalyst in a second process step, and, in a third process step, the selectively hydrogenated and aromatics-containing products from the second process step are then separated into aromatics and non-aromatic compounds by extractive distillation and/or liquid-liquid extraction. The hydrogenation conditions of the second process step are adjusted such that non-aromatic unsaturated hydrocarbons such as especially olefins, diolefins and triolefins are hydrogenated as well and conjugated diolefins and triolefins are hydrogenated as fully as possible.
DE 1568940 A1 describes a process for the separation of aromatics from hydrocarbon mixtures of any aromatics content, which may contain paraffins, cycloparaffins, olefins, diolefins and organic sulphur compounds as non-aromatic components, by extractive distillation. In the extractive distillation, especially N-substituted morpholines are used the substituents of which do not have more than seven C atoms. The aromatics fraction obtained can be submitted to a post-treatment, reference being made to a downstream sulphuric acid washing or a clay treatment. The impurities in the extracting agent, which especially consist of unsaturated hydrocarbons, gather in the bottom phase of the column and can be separated by bottom phase dehydrogenation and extractive distillation.
DE 10019196 C1 describes a process for the recovery of a high-purity aromatics product consisting of benzene and toluene or toluene and xylene from a close-boiling or azeotropic boiling intermediate product containing non-aromatic compounds and an apparatus for carrying out the process. The extractive distillation of non-aromatic compounds and the recovery of the extracting agent are performed in a single column consisting of a column main section comprising two parallel compartments, a rectifying section above the column main section, a stripping section below the column main section and a bottom with associated bottom heating. The starting gasoline is previously separated into at least two fractions by way of distillation, one of which is an aromatics fraction containing higher boiling non-aromatic compounds and a second is an aromatics fraction containing lower boiling non-aromatic compounds. The two fractions are introduced at separate feed points of the compartment of the column main section which is open at the upper and the lower end, the higher boiling aromatics fraction being introduced above the lower boiling aromatics fraction.
It is therefore the aim to provide a process in which an aromatics-rich starting gasoline is first depleted from the non-aromatic hydrocarbons by extractive distillation and the resulting aromatics concentrate is dealkylated by hydrogenation and converted into benzene or dealkylated aromatics as a product. After the hydrodealkylation the obtained aromatics concentrate should have such purity level that simple processing such as flashing, rectifying or both is enough to purify it. Depending on the design it should also be possible to add another hydrogenation treatment between the process steps of extractive distillation and hydrodealkylation in order to remove the residual olefins and polyunsaturated non-aromatic hydrocarbons.
Suitable feed gasolines for the extractive distillation, which have an adequately high content of aromatics, are, for instance, coke-oven light oil refined under pressure, fully hydrogenated pyrolysis gasoline or reformate gasoline which is usually obtained in large quantities in refineries. Depending on the starting gasoline it may be distilled into fractions before being used to increase the content in aromatics.
The invention achieves the aim by a process based on an aromatics-rich starting gasoline which is consecutively purified by extractive distillation first and finally dealkylated by hydrogenation. Depending on the amounts of hydrogen and gasoline cut used, benzene is obtained or alkylated aromatics. From an aromatics-rich starting gasoline an aromatics concentrate rich in benzene or alkylated benzene derivatives is obtained, which, depending on the starting mixture, mainly contains toluene, xylenes and mesitylenes. The alkyl side chains are converted into alkanes during hydrogenation. Higher alkanes resulting from the hydrodealkylation of the side chains may fully be converted into methane as a result of the hydrogenation. The aromatics fractions obtained may, for example, be purified by rectification. Depending on the hydrogenation type and the purification steps the aromatics concentrate may be obtained with any purity level and dealkylation degree.
Carrying out the hydrodealkylation after the extractive distillation saves a significant amount of hydrogen, as the non-aromatic compounds which are contained in the starting gasoline are separated by the extractive distillation before the hydrodealkylation. As the gas amount of hydrogen as well as that of alkanes produced during the hydrogenation of the olefins is lower than in conventional processes, it is also possible to achieve a higher throughput of aromatics product.
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Process For The Recovery Of Pure Aromatics From Hydrocarbon Fractions Containing Aromatics
United States Patent Application 20120067776
Inventors:
Diehl, Thomas (Frankfurt, DE)
Gehrke, Helmut (Bergkamen, DE)
Kolbe, Baerbel (Witten, DE)
Wilken, Dieter (Oelde, DE)
Application Number: 13/138587
Publication Date:03/22/2012
Assignee: UHDE GMBH (Dortmund, DE)
Abstract:
A process for the recovery of a pure aromatics-containing product is disclosed. This product is obtained by extractive distillation of a gasoline rich in aromatics, in which olefins, diolefins and polyolefins are separated, and this extractive distillation is followed by a hydrogenation of the recovered aromatics-rich, olefin-lean product stream, in which the alkylated aromatics, especially toluene and xylene, are dealkylated and the paraffinic dealkylation products further converted into methane so that a significant portion of hydrogen can be saved by carrying out the hydrogenation subsequent to the extractive distillation, as the aromatics mixture is then free of olefins and no hydrogen is required for an olefin hydrogenation, with extractive distillation and recovery of the extracting solvent taking place in one column. An apparatus for carrying out the process described is also disclosed. A column is preferably used for the extractive distillation which allows performing the extractive distillation with a solvent recycling system so that it is not required to provide an additional stripping column for removing the extracting solvent.
Description:The invention relates to a process for the recovery of pure aromatics from aromatics-containing hydrocarbon fractions and, in particular, from reformate gasoline, from fully hydrogenated pyrolysis gasoline, from coke-oven light oil refined under pressure or from mixtures thereof. The process according to the invention serves to provide aromatics and especially benzene, the alkylated benzene derivatives of the aromatics factions being converted by hydrodealkylation to give benzene or lower alkylated benzene derivatives. Depending on the design of the process high-purity products can be produced. By a novel process configuration it is possible to achieve a significant saving in expensive hydrogen used for the hydrodealkylation and in technical equipment. The invention also relates to an apparatus which serves to carry out this process.
Aromatics, particularly benzene, toluene and xylenes are important feedstocks used in the chemical industry, especially for the production of plastics and man-made fibres. In addition, aromatics are used to boost the octane number of Otto fuel. For the chemical industry application it is favourable to provide the required aromatics in the form of pure benzene as the demand for this chemical is especially high.
To recover benzene by hydrodealkylation, reformate gasoline, fully hydrogenated pyrolysis gasoline, coke-oven light oil refined under pressure or mixtures thereof may be used as hydrocarbon mixtures rich in aromatics. These feed products or mixtures thereof are hereinafter referred to as gasoline fractions. The used gasoline fractions contain major amounts of benzene derivatives, especially alkylaromatics. These can be converted by thermal or catalytic hydrogenation to give benzene, in which the alkyl substituents of the benzene are released and fully hydrogenated by reaction with hydrogen. This process of hydrodealkylation (“HDA”) serves to obtain the required benzene. Apart from the required benzene, the alkyl substituents are obtained in the form of alkanes.
The reformate gasoline is a benzene rich in aromatics, which is produced by reforming and especially catalytic reforming of naphtha. During the reforming process, the alkanes and cycloalkanes contained in the petroleum or crude oil are subject to isomerizations, rearrangements, cyclizations, dehydrogenations and similar reactions. The aromatics-rich reformate gasoline obtained from catalytic reforming serves as an important feedstock in the recovery of aromatics.
The fully hydrogenated pyrolysis gasoline is a gasoline rich in aromatics which is obtained from steam cracking of hydrocarbons. Steam cracking of hydrocarbons mainly serves to generate lower olefins, especially ethene. Depending on the boiling range of the hydrocarbon mixture used for steam cracking, a large amount of a by-product rich in aromatics is obtained, the so-called pyrolysis gasoline, which, for further processing, is yet to be freed from unsaturated compounds and hetero-atoms (sulphur, nitrogen, oxygen) in various hydrogenation steps (selective hydrogenation, full hydrogenation). The product obtained from the hydrogenation steps is an aromatics-rich fraction which is referred to as a fully hydrogenated pyrolysis gasoline.
The coke-oven light oil refined under pressure is also a product rich in aromatics. Coke-oven crude light oil is obtained from the coking of coal. Similar to the pyrolysis gasoline, this coke-oven crude light oil still contains unsaturated compounds and hetero-atomic compounds apart from aromatics. Similar to the treatment of the pyrolysis gasoline, the coke-oven crude light oil is also hydrogenated to convert the unsaturated compounds as well as the hetero-atomic compounds. One of the products of this conversion is an aromatics-rich product which is free of unsaturated compounds and hetero-atomic compounds and can be used in a subsequent process. This aromatics-rich product is also referred to as coke-oven light oil refined under pressure.
The aromatics-rich hydrocarbon mixtures used may contain major amounts of non-aromatic compounds such as especially paraffins and naphthenes or olefins which are also hydrogenated in the hydrodealkylation giving alkane as hydrogenation product. If the hydrogenation is continued, methane is obtained from the cracking of alkanes. Depending on the stoichiometric amount of hydrogen used, the hydrodealkylation can also give lower alkylated benzene derivatives which have not been dealkylated completely to benzene.
The presence of large amounts of non-aromatic compounds in the feed stream to the hydrodealkylation requires an adequately large amount of hydrogen to carry out the reaction since hydrogen is not only required to dealkylate the alkylaromatics by hydrogenation to give benzene or lower alkylated benzene derivatives but also to decompose the longer chain non-aromatic compounds to short chain non-aromatic compounds. If the longer chain compounds are decomposed completely, methane is obtained. Therefore it is an aim of the invention to provide a process for the hydrodealkylation which minimises the use of hydrogen.
Apart from the required benzene, the hydrodealkylation also gives a mixture of short-chain paraffins and/or methane. The amount of gas generated by the dealkylation of aromatics cannot be influenced by the process according to the invention. It is, however, also the aim of this invention to reduce the amount of gas generated by the hydrogenation of the non-aromatic compounds also entrained in the feed stream.
To achieve these aims it is advantageous to first purify the hydrocarbon fraction to be submitted to hydrodealkylation in an extractive distillation. By carrying out the extractive distillation it is possible to separate a major part of the non-aromatic compounds already. The aromatics concentrate obtained from the extractive distillation can then be passed to a hydrodealkylation. As no hydrogen is consumed by the chain-shortening hydrogenation of the non-aromatic compounds which have already been removed from the starting mixture by an extractive distillation, a reduction in the amount of hydrogen consumed by the hydrodealkylation is achieved. In addition, the substance mixture contains lower portions of gaseous paraffins owing to the upstream installation of the extractive distillation after the hydrodealkylation. In this way it is possible to design the whole process for a lower gas flow rate which is of advantageous effect.
EP 792928 B1 describes a process for the recovery of pure aromatics from reformate gasoline. The teaching discloses a process in which, in a first process step, a reformate cut with aromatics of a selected carbon number or with aromatics of several selected carbon numbers Cx, Cy is recovered from the reformate gasoline by fractionating distillation and the aromatics cut is hydrogenated selectively via a hydrogenating catalyst in a second process step, and, in a third process step, the selectively hydrogenated and aromatics-containing products from the second process step are then separated into aromatics and non-aromatic compounds by extractive distillation and/or liquid-liquid extraction. The hydrogenation conditions of the second process step are adjusted such that non-aromatic unsaturated hydrocarbons such as especially olefins, diolefins and triolefins are hydrogenated as well and conjugated diolefins and triolefins are hydrogenated as fully as possible.
DE 1568940 A1 describes a process for the separation of aromatics from hydrocarbon mixtures of any aromatics content, which may contain paraffins, cycloparaffins, olefins, diolefins and organic sulphur compounds as non-aromatic components, by extractive distillation. In the extractive distillation, especially N-substituted morpholines are used the substituents of which do not have more than seven C atoms. The aromatics fraction obtained can be submitted to a post-treatment, reference being made to a downstream sulphuric acid washing or a clay treatment. The impurities in the extracting agent, which especially consist of unsaturated hydrocarbons, gather in the bottom phase of the column and can be separated by bottom phase dehydrogenation and extractive distillation.
DE 10019196 C1 describes a process for the recovery of a high-purity aromatics product consisting of benzene and toluene or toluene and xylene from a close-boiling or azeotropic boiling intermediate product containing non-aromatic compounds and an apparatus for carrying out the process. The extractive distillation of non-aromatic compounds and the recovery of the extracting agent are performed in a single column consisting of a column main section comprising two parallel compartments, a rectifying section above the column main section, a stripping section below the column main section and a bottom with associated bottom heating. The starting gasoline is previously separated into at least two fractions by way of distillation, one of which is an aromatics fraction containing higher boiling non-aromatic compounds and a second is an aromatics fraction containing lower boiling non-aromatic compounds. The two fractions are introduced at separate feed points of the compartment of the column main section which is open at the upper and the lower end, the higher boiling aromatics fraction being introduced above the lower boiling aromatics fraction.
It is therefore the aim to provide a process in which an aromatics-rich starting gasoline is first depleted from the non-aromatic hydrocarbons by extractive distillation and the resulting aromatics concentrate is dealkylated by hydrogenation and converted into benzene or dealkylated aromatics as a product. After the hydrodealkylation the obtained aromatics concentrate should have such purity level that simple processing such as flashing, rectifying or both is enough to purify it. Depending on the design it should also be possible to add another hydrogenation treatment between the process steps of extractive distillation and hydrodealkylation in order to remove the residual olefins and polyunsaturated non-aromatic hydrocarbons.
Suitable feed gasolines for the extractive distillation, which have an adequately high content of aromatics, are, for instance, coke-oven light oil refined under pressure, fully hydrogenated pyrolysis gasoline or reformate gasoline which is usually obtained in large quantities in refineries. Depending on the starting gasoline it may be distilled into fractions before being used to increase the content in aromatics.
The invention achieves the aim by a process based on an aromatics-rich starting gasoline which is consecutively purified by extractive distillation first and finally dealkylated by hydrogenation. Depending on the amounts of hydrogen and gasoline cut used, benzene is obtained or alkylated aromatics. From an aromatics-rich starting gasoline an aromatics concentrate rich in benzene or alkylated benzene derivatives is obtained, which, depending on the starting mixture, mainly contains toluene, xylenes and mesitylenes. The alkyl side chains are converted into alkanes during hydrogenation. Higher alkanes resulting from the hydrodealkylation of the side chains may fully be converted into methane as a result of the hydrogenation. The aromatics fractions obtained may, for example, be purified by rectification. Depending on the hydrogenation type and the purification steps the aromatics concentrate may be obtained with any purity level and dealkylation degree.
Carrying out the hydrodealkylation after the extractive distillation saves a significant amount of hydrogen, as the non-aromatic compounds which are contained in the starting gasoline are separated by the extractive distillation before the hydrodealkylation. As the gas amount of hydrogen as well as that of alkanes produced during the hydrogenation of the olefins is lower than in conventional processes, it is also possible to achieve a higher throughput of aromatics product.
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Catalyst And Process For Producing Light Aromatic Hydrocarbons And Light Alkanes From Hydrocarbonaceous Feedstock
PATENT
Catalyst And Process For Producing Light Aromatic Hydrocarbons And Light Alkanes From Hydrocarbonaceous Feedstock
United States Patent Application 20120053382
Inventors:
Wang, Deju (Shanghai, CN)
Liu, Zhongneng (Shanghai, CN)
LI, Xueli (Shanghai, CN)
Hou, Minbo (Shanghai, CN)
Wang, Zheming (Shanghai, CN)
Wang, Jianqiang (Shanghai, CN)
Application Number: 13/290596
Publication Date: 03/01/2012
Assignee:
SHANGHAI RESEARCH INSTITUTE OF PETROCHEMICAL TECHNOLOGY SINOPEC (Shanghai, CN)
CHINA PETROLEUM & CHEMICAL CORPORATION (Beijing, CN)
Abstract:
The present invention provides a catalyst comprising metallic Pt and/or Pd supported on a binder-free zeolite for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock, wherein the amount of metallic Pt and/or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5 wt % on the basis of the total weight of the catalyst, and the binder-free zeolite is selected from the group consisting of mordenite, beta zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or cocrystal zeolite thereof. The present invention also provides a process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock using said catalyst.
TECHNICAL FIELD
The present invention relates to a catalyst as well as the corresponding process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock.
BACKGROUND ART
Regarding the separation of aromatic hydrocarbons BTX, i.e., benzene, toluene and xylene, from non-aromatic hydrocarbons, some catalytic conversion processes have been developed in the prior art. For example, U.S. Pat. No. 3,729,409 disclosed converting non-aromatic hydrocarbons to lower alkanes by hydrocracking reaction and then separating aromatic hydrocarbons from non-aromatic hydrocarbons through gas-liquid separation; U.S. Pat. No. 5,865,986 and U.S. Pat. No. 6,001,241 disclosed a process for upgrading naphtha fraction, wherein a zeolite-based catalyst is used in some reactors to improve the production of aromatic hydrocarbons; and CN1217892C disclosed a similar process, wherein reformate, pyrolysis gasoline and the like are upgrade to produce LPG and light aromatic hydrocarbons.
The acidic catalyst used in these catalytic conversion processes would deactivate quickly due to coke and/or carbon-deposition, although this can be alleviated by supporting the metals with high hydrogenation activity and the hydrogenation activity of the catalyst also can be adjusted by varying the amount and/or the distribution of the supported metals, however, too high hydrogenation activity on the metallic center may result in side reaction of saturation of aromatic rings. With this regard, U.S. Pat. No. 5,865,986 proposed to adjust the metallic activity with sulfur compounds. Furthermore, U.S. Pat. No. 6,001,241 proposed to use Pb or Bi to control the degree of hydrogenation.
On the other hand, the zeolite molecular sieve powder used for said catalysts are generally manufactured into shaped particles with certain mechanical strengths and shapes, and during this manufacture some binders e.g. oxides such as Al2O3, SiO2, TiO2 and the like as well as clay minerals are needed usually. This is because the shaped catalysts are widely used in industries and have to suffer from various stresses during its use, thus, sufficient mechanical strengths are necessary for ensuring the whole catalytic process to be conducted smoothly, otherwise if the shaped catalysts have poor mechanical strengths, some problems such as the lines being blocked by fine powders, the liquid being distributed unevenly, the pressure drop being increased and the like would be introduced, so as to lead to poor catalytic efficiency, and even a unexpected shut-down in worse case.
However, introduction of binders during shaping the zeolite powders would reduce the concentration of effective components in the zeolite particles, resulting in reduced effective surface area, and thus the adsorption value would be reduced. This is because some binders would enter into part of channels of the zeolite or block part of pores of the zeolite, thus limiting the diffusion, resulting in poor adsorption ability and adsorption selectivity as well as reduced rates of adsorption and desorption, further the reduced activity and selectivity in the catalytic reactions; furthermore, undesired side reactions may be initiated in the presence of binders.
Regarding the above-mentioned disadvantages in connection with the introduction of binders during shaping the zeolite powders, the inventors have tried to develop a process for producing a binder-free zeolite, c.f. CN1915820A, which is incorporated herein by reference. The binder-free zeolite means that the shaped zeolite particles do not comprise inert binders, thus having high concentration of zeolite and large available surface area; furthermore, better properties in adsorption separation and ion exchange as well as better catalytic properties in some reactions are shown.
Based on the above-mentioned finding, the inventors further tried to develop a catalyst using said binder-free zeolite particles as support. Said catalyst has higher catalytic activity and stability and can be used for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock.
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Catalyst And Process For Producing Light Aromatic Hydrocarbons And Light Alkanes From Hydrocarbonaceous Feedstock
United States Patent Application 20120053382
Inventors:
Wang, Deju (Shanghai, CN)
Liu, Zhongneng (Shanghai, CN)
LI, Xueli (Shanghai, CN)
Hou, Minbo (Shanghai, CN)
Wang, Zheming (Shanghai, CN)
Wang, Jianqiang (Shanghai, CN)
Application Number: 13/290596
Publication Date: 03/01/2012
Assignee:
SHANGHAI RESEARCH INSTITUTE OF PETROCHEMICAL TECHNOLOGY SINOPEC (Shanghai, CN)
CHINA PETROLEUM & CHEMICAL CORPORATION (Beijing, CN)
Abstract:
The present invention provides a catalyst comprising metallic Pt and/or Pd supported on a binder-free zeolite for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock, wherein the amount of metallic Pt and/or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5 wt % on the basis of the total weight of the catalyst, and the binder-free zeolite is selected from the group consisting of mordenite, beta zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or cocrystal zeolite thereof. The present invention also provides a process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock using said catalyst.
TECHNICAL FIELD
The present invention relates to a catalyst as well as the corresponding process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock.
BACKGROUND ART
Regarding the separation of aromatic hydrocarbons BTX, i.e., benzene, toluene and xylene, from non-aromatic hydrocarbons, some catalytic conversion processes have been developed in the prior art. For example, U.S. Pat. No. 3,729,409 disclosed converting non-aromatic hydrocarbons to lower alkanes by hydrocracking reaction and then separating aromatic hydrocarbons from non-aromatic hydrocarbons through gas-liquid separation; U.S. Pat. No. 5,865,986 and U.S. Pat. No. 6,001,241 disclosed a process for upgrading naphtha fraction, wherein a zeolite-based catalyst is used in some reactors to improve the production of aromatic hydrocarbons; and CN1217892C disclosed a similar process, wherein reformate, pyrolysis gasoline and the like are upgrade to produce LPG and light aromatic hydrocarbons.
The acidic catalyst used in these catalytic conversion processes would deactivate quickly due to coke and/or carbon-deposition, although this can be alleviated by supporting the metals with high hydrogenation activity and the hydrogenation activity of the catalyst also can be adjusted by varying the amount and/or the distribution of the supported metals, however, too high hydrogenation activity on the metallic center may result in side reaction of saturation of aromatic rings. With this regard, U.S. Pat. No. 5,865,986 proposed to adjust the metallic activity with sulfur compounds. Furthermore, U.S. Pat. No. 6,001,241 proposed to use Pb or Bi to control the degree of hydrogenation.
On the other hand, the zeolite molecular sieve powder used for said catalysts are generally manufactured into shaped particles with certain mechanical strengths and shapes, and during this manufacture some binders e.g. oxides such as Al2O3, SiO2, TiO2 and the like as well as clay minerals are needed usually. This is because the shaped catalysts are widely used in industries and have to suffer from various stresses during its use, thus, sufficient mechanical strengths are necessary for ensuring the whole catalytic process to be conducted smoothly, otherwise if the shaped catalysts have poor mechanical strengths, some problems such as the lines being blocked by fine powders, the liquid being distributed unevenly, the pressure drop being increased and the like would be introduced, so as to lead to poor catalytic efficiency, and even a unexpected shut-down in worse case.
However, introduction of binders during shaping the zeolite powders would reduce the concentration of effective components in the zeolite particles, resulting in reduced effective surface area, and thus the adsorption value would be reduced. This is because some binders would enter into part of channels of the zeolite or block part of pores of the zeolite, thus limiting the diffusion, resulting in poor adsorption ability and adsorption selectivity as well as reduced rates of adsorption and desorption, further the reduced activity and selectivity in the catalytic reactions; furthermore, undesired side reactions may be initiated in the presence of binders.
Regarding the above-mentioned disadvantages in connection with the introduction of binders during shaping the zeolite powders, the inventors have tried to develop a process for producing a binder-free zeolite, c.f. CN1915820A, which is incorporated herein by reference. The binder-free zeolite means that the shaped zeolite particles do not comprise inert binders, thus having high concentration of zeolite and large available surface area; furthermore, better properties in adsorption separation and ion exchange as well as better catalytic properties in some reactions are shown.
Based on the above-mentioned finding, the inventors further tried to develop a catalyst using said binder-free zeolite particles as support. Said catalyst has higher catalytic activity and stability and can be used for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock.
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Rational catalyst design for the ammonia decomposition reaction
THESIS
Rational catalyst design for the ammonia decomposition reaction
by Hansgen, Danielle Ann, Ph.D., UNIVERSITY OF DELAWARE, 2011, 188 pages; 3473687
Abstract:
The ammonia decomposition reaction was explored through multiscale microkinetic modeling for a number of transition metal catalysts, including Pt, Pd, Ir, Ni, Rh, Co, Ru, Re, and Mo, to better understand the reaction mechanism.
An understanding of the reaction mechanism and electronic properties of these metals has given insight into how to tailor catalysts to improve catalytic activity for this reaction. The mechanism consists of 12 elementary reaction steps and 5 surface species, namely N, H, NH, NH2, and NH3. For many of the metals, a large portion of the surface is covered by adsorbates. For these metals, repulsive adsorbate-adsorbate interactions were found to change the binding energies of the surface species, thereby changing the elementary reaction activation barriers and modifying the catalytic activity. Coverage dependent atomic heats of chemisorption were calculated through density functional theory (DFT) using the Vienna ab-initio Simulation Package (VASP) for the various transition metal catalysts. Coverage dependent molecular binding energies and activation barriers were calculated through the bond-order conservation (BOC) method.
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Rational catalyst design for the ammonia decomposition reaction
by Hansgen, Danielle Ann, Ph.D., UNIVERSITY OF DELAWARE, 2011, 188 pages; 3473687
Abstract:
The ammonia decomposition reaction was explored through multiscale microkinetic modeling for a number of transition metal catalysts, including Pt, Pd, Ir, Ni, Rh, Co, Ru, Re, and Mo, to better understand the reaction mechanism.
An understanding of the reaction mechanism and electronic properties of these metals has given insight into how to tailor catalysts to improve catalytic activity for this reaction. The mechanism consists of 12 elementary reaction steps and 5 surface species, namely N, H, NH, NH2, and NH3. For many of the metals, a large portion of the surface is covered by adsorbates. For these metals, repulsive adsorbate-adsorbate interactions were found to change the binding energies of the surface species, thereby changing the elementary reaction activation barriers and modifying the catalytic activity. Coverage dependent atomic heats of chemisorption were calculated through density functional theory (DFT) using the Vienna ab-initio Simulation Package (VASP) for the various transition metal catalysts. Coverage dependent molecular binding energies and activation barriers were calculated through the bond-order conservation (BOC) method.
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Method Of Producing Alkylbenzene And Catalyst Used Therefor
PATENT
Method Of Producing Alkylbenzene And Catalyst Used Therefor
United States Patent Application 20120000819
Inventors:
Matsushita, Koichi (Tokyo, JP)
Application Number: 13/259781
Publication Date: 01/05/2012
Assignee:
JX NIPPON OIL & ENERGY CORPORATION (Tokyo, JP)
JAPAN PETROLEUM ENERGY CENTER (Tokyo, JP)
Abstract:
A method that efficiently produces an alkylbenzene with a high added value from a 1.5-cyclic aromatic hydrocarbon while suppressing excessive hydrocracking and nuclear hydrogenation, and preventing a decrease in catalytic activity due to deposition of carbon during a hydrocracking reaction, and a catalyst used therefor, are disclosed. A method of producing an alkylbenzene includes causing a hydrocarbon oil feedstock containing an alkylbenzene content of less than 20 vol %, a bicyclic aromatic hydrocarbon content of less than 30 vol %, and a 1.5-cyclic aromatic hydrocarbon content of 25 vol % or more to come in contact with a hydrocracking catalyst that includes a solid acid having a maximum acid strength of Brönsted acid of 110 kJ/mol or more and less than 140 kJ/mol.
TECHNICAL FIELD
The invention relates to a method for efficiently producing an alkylbenzene with a high added value, and a catalyst used therefor, wherein the method allows a minimum naphthene ring-opening reaction to occur by causing an appropriate hydrocracking reaction without causing unnecessary nuclear hydrogenation.
BACKGROUND ART
In the petroleum refining field, an alkylbenzene such as benzene, toluene, and xylene (BTX) has been produced by a catalytic reforming process. A catalytic reforming reaction basically does not cause a change in the number of carbon atoms of the feedstock. Attempts have been made to convert heavy oil having a large number of carbon atoms into light oil (e.g., gasoline fraction). A solid acid has been known as a catalyst for a cracking reaction that reduces the number of carbon atoms of the feedstock.
For example, Patent Literatures 1 and 2 disclose a method of upgrading a light cycle oil (LCO) using a catalyst that contains molybdenum and β zeolite or a group VIII or VI metal in the periodic table and ultrastable Y zeolite as the solid acid. However, this method aims at producing gasoline, and does not selectively produce BTX and the like. When separating BTX and the like as a product, the amount of alkylbenzene produced by this method is insufficient.
Patent Literatures 3, 4, and 5 disclose a method of producing a lubricant base oil or a middle distillate using a solid acid having specific acidity containing ultrastable Y zeolite, an amorphous cracking component, and a group VIII or VI metal in the periodic table. However, a method that efficiently produces an alkylbenzene from a 1.5-cyclic aromatic hydrocarbon that has one benzene ring and one naphthene ring has not been disclosed.
Patent Literature 6 discloses a method of producing a high-octane gasoline blending component by hydrocracking a petroleum hydrocarbon having an aromatic hydrocarbon content of 40 mass % or more using a catalyst obtained by causing a group VIII metal and a group VI metal in the periodic table having hydrogenation activity to be supported on crystalline aluminosilicate zeolite containing particles having particle diameters of 0.5 μm or less in an amount of 80 vol % or more. However, this method aims at producing a gasoline blending component, and does not selectively produce an alkylbenzene. Moreover, since the crystalline aluminosilicate zeolite having an MFI structure represented by the so-called ZSM-5 has a maximum acid strength as high as 140 kJ/mol or more, the yield of gasoline is less than 70 vol %, and the reaction liquid yield is low due to a high cracking rate.
The inventor of the invention proposed a method that selectively produces a monocyclic aromatic hydrocarbon by hydrocracking a polycyclic aromatic hydrocarbon in the presence of a zeolite catalyst (Patent Literature 7), and a method that produces an alkylbenzene by hydrocracking a refilled oil obtained by refining a heavy hydrocarbon in the presence of a zeolite catalyst (Patent Literature 8). However, the method disclosed in Patent Literature 7 produces an alkylbenzene from an aromatic hydrocarbon having two or more rings (e.g., naphthalene rings). Since the hydrocracking catalyst used in Patent Literature 8 has a high maximum acid strength of Brönsted acid, only a small amount of alkylbenzene is produced
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Method Of Producing Alkylbenzene And Catalyst Used Therefor
United States Patent Application 20120000819
Inventors:
Matsushita, Koichi (Tokyo, JP)
Application Number: 13/259781
Publication Date: 01/05/2012
Assignee:
JX NIPPON OIL & ENERGY CORPORATION (Tokyo, JP)
JAPAN PETROLEUM ENERGY CENTER (Tokyo, JP)
Abstract:
A method that efficiently produces an alkylbenzene with a high added value from a 1.5-cyclic aromatic hydrocarbon while suppressing excessive hydrocracking and nuclear hydrogenation, and preventing a decrease in catalytic activity due to deposition of carbon during a hydrocracking reaction, and a catalyst used therefor, are disclosed. A method of producing an alkylbenzene includes causing a hydrocarbon oil feedstock containing an alkylbenzene content of less than 20 vol %, a bicyclic aromatic hydrocarbon content of less than 30 vol %, and a 1.5-cyclic aromatic hydrocarbon content of 25 vol % or more to come in contact with a hydrocracking catalyst that includes a solid acid having a maximum acid strength of Brönsted acid of 110 kJ/mol or more and less than 140 kJ/mol.
TECHNICAL FIELD
The invention relates to a method for efficiently producing an alkylbenzene with a high added value, and a catalyst used therefor, wherein the method allows a minimum naphthene ring-opening reaction to occur by causing an appropriate hydrocracking reaction without causing unnecessary nuclear hydrogenation.
BACKGROUND ART
In the petroleum refining field, an alkylbenzene such as benzene, toluene, and xylene (BTX) has been produced by a catalytic reforming process. A catalytic reforming reaction basically does not cause a change in the number of carbon atoms of the feedstock. Attempts have been made to convert heavy oil having a large number of carbon atoms into light oil (e.g., gasoline fraction). A solid acid has been known as a catalyst for a cracking reaction that reduces the number of carbon atoms of the feedstock.
For example, Patent Literatures 1 and 2 disclose a method of upgrading a light cycle oil (LCO) using a catalyst that contains molybdenum and β zeolite or a group VIII or VI metal in the periodic table and ultrastable Y zeolite as the solid acid. However, this method aims at producing gasoline, and does not selectively produce BTX and the like. When separating BTX and the like as a product, the amount of alkylbenzene produced by this method is insufficient.
Patent Literatures 3, 4, and 5 disclose a method of producing a lubricant base oil or a middle distillate using a solid acid having specific acidity containing ultrastable Y zeolite, an amorphous cracking component, and a group VIII or VI metal in the periodic table. However, a method that efficiently produces an alkylbenzene from a 1.5-cyclic aromatic hydrocarbon that has one benzene ring and one naphthene ring has not been disclosed.
Patent Literature 6 discloses a method of producing a high-octane gasoline blending component by hydrocracking a petroleum hydrocarbon having an aromatic hydrocarbon content of 40 mass % or more using a catalyst obtained by causing a group VIII metal and a group VI metal in the periodic table having hydrogenation activity to be supported on crystalline aluminosilicate zeolite containing particles having particle diameters of 0.5 μm or less in an amount of 80 vol % or more. However, this method aims at producing a gasoline blending component, and does not selectively produce an alkylbenzene. Moreover, since the crystalline aluminosilicate zeolite having an MFI structure represented by the so-called ZSM-5 has a maximum acid strength as high as 140 kJ/mol or more, the yield of gasoline is less than 70 vol %, and the reaction liquid yield is low due to a high cracking rate.
The inventor of the invention proposed a method that selectively produces a monocyclic aromatic hydrocarbon by hydrocracking a polycyclic aromatic hydrocarbon in the presence of a zeolite catalyst (Patent Literature 7), and a method that produces an alkylbenzene by hydrocracking a refilled oil obtained by refining a heavy hydrocarbon in the presence of a zeolite catalyst (Patent Literature 8). However, the method disclosed in Patent Literature 7 produces an alkylbenzene from an aromatic hydrocarbon having two or more rings (e.g., naphthalene rings). Since the hydrocracking catalyst used in Patent Literature 8 has a high maximum acid strength of Brönsted acid, only a small amount of alkylbenzene is produced
Free Full Text Source: http://www.freepatentsonline.com/y2012/0000819.html
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