The Canadian Journal of Chemical Engineering, Early View (Online Version
of Record published before inclusion in an issue), Article first published
online: 19 DEC 2011
Micellar enhanced ultrafiltration: A comparative
study
S. V.
Jadhav,
K. V. Marathe*
kv.marathe@ictmumbai.edu.in
Department of Chemical Engineering, Institute of Chemical Technology,
Mumbai-400019, India
Abstract
Describes a pilot plant
study designed to evaluate the performance of continuous cross flow micellar
enhanced ultrafiltration (MEUF) method for the simultaneous separation of
phenol and ortho-cresol from the aqueous phase using a cationic surfactant,
cetyltrimethyl ammonium bromide.
The
membranes used were polysulfone tubular hollow fibre membrane with 6 kDa and a ceramic membrane having pore diameter 50 nm with an active layer of microporous zirconia (ZrO2)
supported on α-alumina, respectively. The work compared the effectiveness of
membranes based on pollutants structural parameters, membrane properties and
membrane modules. The characteristic parameters such as the distribution
coefficient (D), micelle binding constant (Kp) and
micelle loading (Lm) were obtained at optimal experimental
conditions.
Full Text Source (Subscription or Fee): http://onlinelibrary.wiley.com/doi/10.1002/cjce.21613/full
Wednesday, February 29, 2012
Influence of TiO2/PVDF Membrane Catalyzed Ozonation of Ammonia Wastewater
Proceedings of the 2011 International Conference on Informatics,
Cybernetics, and Computer Engineering (ICCE2011) November 19–20, 2011,
Melbourne, Australia
Advances in Intelligent and Soft Computing, 2012, Volume 112/2012, 771-778,
Influence of TiO2/PVDF Membrane Catalyzed Ozonation of Ammonia Wastewater
Mo-Jie Sun(1)
Chao Yang(1)
yangchao_66@126.com
Chong Zhang(1)
Chuang-Jie Zhao(2)
zhaochuangjie@cpene.com
Author Affiliations
College of Chemical Engineering, Northeast Dianli University, Jilin City, P.R. China
PetroChina Northeast Refining & Chemical Engineering Co.Ltd, Jilin Design Institute, Jilin City, P.R. China
Abstract
Authors prepared TiO2 entrapped PVDF membranes (TiO2/PVDF) by adding varying amounts of TiO2 particles into the casting solution. They studied the catalytic property of TiO2/PVDF membranes for removing high concentrations of ammonia wastewater.
They investigated a number of factors affecting the removal rate of ammonia. These included crystal of TiO2, ozone dosage, catalyst dosage, residence time, pH value and reaction temperature. Results indicate that the rutile TiO2 has optimum removal effect for ammonia.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/y3r86l6w642704lu/
Advances in Intelligent and Soft Computing, 2012, Volume 112/2012, 771-778,
Influence of TiO2/PVDF Membrane Catalyzed Ozonation of Ammonia Wastewater
Mo-Jie Sun(1)
Chao Yang(1)
yangchao_66@126.com
Chong Zhang(1)
Chuang-Jie Zhao(2)
zhaochuangjie@cpene.com
Author Affiliations
College of Chemical Engineering, Northeast Dianli University, Jilin City, P.R. China
PetroChina Northeast Refining & Chemical Engineering Co.Ltd, Jilin Design Institute, Jilin City, P.R. China
Abstract
Authors prepared TiO2 entrapped PVDF membranes (TiO2/PVDF) by adding varying amounts of TiO2 particles into the casting solution. They studied the catalytic property of TiO2/PVDF membranes for removing high concentrations of ammonia wastewater.
They investigated a number of factors affecting the removal rate of ammonia. These included crystal of TiO2, ozone dosage, catalyst dosage, residence time, pH value and reaction temperature. Results indicate that the rutile TiO2 has optimum removal effect for ammonia.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/y3r86l6w642704lu/
Biochemical Kinetics of Cross flow Membrane Bioreactor Processes in the Treatment of Refinery Wastewater
Int. J. Environ. Res., 6(1):285-296, Winter 2012
Biochemical Kinetics of Cross flow Membrane Bioreactor Processes in the Treatment of Refinery Wastewater
Rahman, M. M. 1 and Al-Malack, M. H.2*
mhmalack@kfupm.edu.sa
1 University of Western Sydney, School of Engineering, Locked Bag 1797, Penrith South DC
NSW 1797, Australia
2 King Fahd University of Petroleum & Minerals, Box 1150, Dhahran 31261, Saudi Arabia
ABSTRACT:
A lab-scale cross flow membrane bioreactor (CF-MBR) was operated to determine the biokinetic coefficients under MLSS concentrations of 5000 and 3000 mg/L. The investigation showed that the yield (Y), the endogenous decay coefficient (kd), the maximum specific growth rate (µm) and the saturation constant (KS) were 0.276 mg/mg, 0.07 /day, 0.653 /day, and 396.62 mg COD/L respectively for MLSS 5000 mg/L, and 0.222 mg/mg, 0.09 /day, 1.2 /day, and 659.45 mg COD/L for MLSS 3000 mg/L.
The values of kinetic coefficients were within the normal range of the activated sludge process found in the literature, except the values of Y. However, value of Y increased with the increase of MLSS. Kinetic parameters determined from CF-MBR process were used to simulate the effluent COD. The simulation study showed good agreement between model prediction and experimental data. Sensitivity analysis was carried out to determine influence of biokinetic parameters on the effluent substrate concentration. From the analysis, it was evident that kd and KS were directly proportional to the effluent substrate concentration, while µm was inversely proportional.
Free Full Text Source: http://scholar.googleusercontent.com/scholar?q=cache:CodY4ZBHGb0J:scholar.google.com/+fouling+refinery+OR+refining&hl=en&as_sdt=0,6&as_ylo=2012&as_yhi=2012
Biochemical Kinetics of Cross flow Membrane Bioreactor Processes in the Treatment of Refinery Wastewater
Rahman, M. M. 1 and Al-Malack, M. H.2*
mhmalack@kfupm.edu.sa
1 University of Western Sydney, School of Engineering, Locked Bag 1797, Penrith South DC
NSW 1797, Australia
2 King Fahd University of Petroleum & Minerals, Box 1150, Dhahran 31261, Saudi Arabia
ABSTRACT:
A lab-scale cross flow membrane bioreactor (CF-MBR) was operated to determine the biokinetic coefficients under MLSS concentrations of 5000 and 3000 mg/L. The investigation showed that the yield (Y), the endogenous decay coefficient (kd), the maximum specific growth rate (µm) and the saturation constant (KS) were 0.276 mg/mg, 0.07 /day, 0.653 /day, and 396.62 mg COD/L respectively for MLSS 5000 mg/L, and 0.222 mg/mg, 0.09 /day, 1.2 /day, and 659.45 mg COD/L for MLSS 3000 mg/L.
The values of kinetic coefficients were within the normal range of the activated sludge process found in the literature, except the values of Y. However, value of Y increased with the increase of MLSS. Kinetic parameters determined from CF-MBR process were used to simulate the effluent COD. The simulation study showed good agreement between model prediction and experimental data. Sensitivity analysis was carried out to determine influence of biokinetic parameters on the effluent substrate concentration. From the analysis, it was evident that kd and KS were directly proportional to the effluent substrate concentration, while µm was inversely proportional.
Free Full Text Source: http://scholar.googleusercontent.com/scholar?q=cache:CodY4ZBHGb0J:scholar.google.com/+fouling+refinery+OR+refining&hl=en&as_sdt=0,6&as_ylo=2012&as_yhi=2012
Application of Polyelectrolyte-Enhanced Ultrafiltration for Rhenium Recovery from Aqueous Solutions
Chemical Engineering & Technology, Volume 35, Issue 2, pages
387–392, February, 2012
Application of Polyelectrolyte-Enhanced Ultrafiltration for Rhenium Recovery from Aqueous Solutions
J. Zeng*,
zengjianxian@163.com
S. Li,
X. Sun,
X. Chen
College of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, China
Abstract
Researchers studied the use of polyelectrolyte-enhanced ultrafiltration for rhenium(VII) recovery from aqueous solutions by using polyquaternium-6 (PQ6) as a complexing agent.
They observed the effects of the operating parameters on the permeate flux (J) and the rhenium rejection coefficient (R). In the process of concentration, J declines slowly and R is about 1. The concentrated solution was used for the decomplexation. In the diafiltration process, rhenium is extracted effectively, and the purification of the regenerated PQ6 is satisfactory. The regenerated PQ6 was used to bind rhenium(VII). The binding capacity of the regenerated PQ6 is close to that of fresh PQ6.
Full Text Source (Subscription or Fee): http://onlinelibrary.wiley.com/doi/10.1002/ceat.201100454/abstract
Application of Polyelectrolyte-Enhanced Ultrafiltration for Rhenium Recovery from Aqueous Solutions
J. Zeng*,
zengjianxian@163.com
S. Li,
X. Sun,
X. Chen
College of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, China
Abstract
Researchers studied the use of polyelectrolyte-enhanced ultrafiltration for rhenium(VII) recovery from aqueous solutions by using polyquaternium-6 (PQ6) as a complexing agent.
They observed the effects of the operating parameters on the permeate flux (J) and the rhenium rejection coefficient (R). In the process of concentration, J declines slowly and R is about 1. The concentrated solution was used for the decomplexation. In the diafiltration process, rhenium is extracted effectively, and the purification of the regenerated PQ6 is satisfactory. The regenerated PQ6 was used to bind rhenium(VII). The binding capacity of the regenerated PQ6 is close to that of fresh PQ6.
Full Text Source (Subscription or Fee): http://onlinelibrary.wiley.com/doi/10.1002/ceat.201100454/abstract
Removal of heavy metals from wastewater using micellar enhanced ultrafiltration technique: a review
Central European Journal of Chemistry, Volume 10, Number 1, 27-46 (2011)
Removal of heavy metals from wastewater using micellar enhanced ultrafiltration technique: a review
Alka A. Mungray(1)
bag@ched.svnit.ac.in
Shrirang V. Kulkarni(1)
Arvind K. Mungray(1)
amungray@yahoo.com
Department of Chemical Engineering, Sardar Vallabhbhai National Institute of Technology, Surat, 395007 India
Abstract
Authors review the application of Micellar enhanced ultrafiltration (MEUF) for the removal of various heavy metals. They deterfmine MEUF to be an economical alternative available to the conventional membrane separation process. This is due to the fact that it reduces the requirement of higher pressure and high membrane costs.
MEUF is a separation processes which uses surfactants and ultrafiltration membranes to remove multivalent ions from wastewater with high percent rejection using electrostatic attraction between metals and micelles. The review determines the effect of the operating parameters on the removal of metal ions. It emphasizes the application of MEUF for the removal of single metal ions, multiple metal ions and different metals along with other organic materials.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/b782348v262kv3l7/
Removal of heavy metals from wastewater using micellar enhanced ultrafiltration technique: a review
Alka A. Mungray(1)
bag@ched.svnit.ac.in
Shrirang V. Kulkarni(1)
Arvind K. Mungray(1)
amungray@yahoo.com
Department of Chemical Engineering, Sardar Vallabhbhai National Institute of Technology, Surat, 395007 India
Abstract
Authors review the application of Micellar enhanced ultrafiltration (MEUF) for the removal of various heavy metals. They deterfmine MEUF to be an economical alternative available to the conventional membrane separation process. This is due to the fact that it reduces the requirement of higher pressure and high membrane costs.
MEUF is a separation processes which uses surfactants and ultrafiltration membranes to remove multivalent ions from wastewater with high percent rejection using electrostatic attraction between metals and micelles. The review determines the effect of the operating parameters on the removal of metal ions. It emphasizes the application of MEUF for the removal of single metal ions, multiple metal ions and different metals along with other organic materials.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/b782348v262kv3l7/
The Coking Wastewater Treatment and Reuse of Depth
Advanced Materials Research (Volumes 347 - 353), Pages 1310-1313 (2011)
The Coking Wastewater Treatment and Reuse of Depth
Xiu Hui Zhu, Yue Shen, Ting Ting Peng, Lian Yu He, Geng Han Yang, Chun Fang Zheng
Abstract
Authors used water quality stability theory to determine that coking wastewater could be used as cooling water to enhance water treatment and control technology.
Full Text Source (Subscription or Fee): http://www.scientific.net/AMR.347-353.1310
The Coking Wastewater Treatment and Reuse of Depth
Xiu Hui Zhu, Yue Shen, Ting Ting Peng, Lian Yu He, Geng Han Yang, Chun Fang Zheng
Abstract
Authors used water quality stability theory to determine that coking wastewater could be used as cooling water to enhance water treatment and control technology.
Full Text Source (Subscription or Fee): http://www.scientific.net/AMR.347-353.1310
Effect-Directed Assessment of the Bioaccumulation Potential and Chemical Nature of Ah Receptor Agonists in Crude and Refined Oils.
Environ. Sci. Technol., 2012, 46 (3), pp 1572–1580
Effect-Directed Assessment of the Bioaccumulation Potential and Chemical Nature of Ah Receptor Agonists in Crude and Refined Oils.
Cozmina M. Vrabie†, Theo L. Sinnige†, Albertinka J. Murk‡, and Michiel T. O. Jonker†*
m.t.o.jonker@uu.nl
† Institute for Risk Assessment Sciences, Utrecht University; P.O. Box 80177, 3508 TD Utrecht, The Netherlands.
‡ Section Toxicology, Wageningen University, P.O. Box 8000, 6700 EA, Wageningen, The Netherlands and Wageningen IMARES, P.O. Box 68, 1970 AB IJmuiden, The Netherlands.
According to recent studies certain chemicals in crude oils and refined petroleum products may induce specific modes of action, such as aryl hydrocarbon receptor (AhR) agonism. A study showed that AhR agonists bioaccumulate from oil-spiked sediments into aquatic worms and persist in the worms for at least several weeks.
Chemical fractionations of eight pure oils into saturates, aromatics, resins, and asphaltenes (SARA), followed by effect-directed analyses using in vitro reporter gene assays revealed that the agonists predominantly are aromatic and resin-like chemicals. Based on study results, authors advocate an adapted risk assessment approach for complex mixtures in which low concentrations of very potent compounds are responsible for mixture effects.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/es2036948
Effect-Directed Assessment of the Bioaccumulation Potential and Chemical Nature of Ah Receptor Agonists in Crude and Refined Oils.
Cozmina M. Vrabie†, Theo L. Sinnige†, Albertinka J. Murk‡, and Michiel T. O. Jonker†*
m.t.o.jonker@uu.nl
† Institute for Risk Assessment Sciences, Utrecht University; P.O. Box 80177, 3508 TD Utrecht, The Netherlands.
‡ Section Toxicology, Wageningen University, P.O. Box 8000, 6700 EA, Wageningen, The Netherlands and Wageningen IMARES, P.O. Box 68, 1970 AB IJmuiden, The Netherlands.
According to recent studies certain chemicals in crude oils and refined petroleum products may induce specific modes of action, such as aryl hydrocarbon receptor (AhR) agonism. A study showed that AhR agonists bioaccumulate from oil-spiked sediments into aquatic worms and persist in the worms for at least several weeks.
Chemical fractionations of eight pure oils into saturates, aromatics, resins, and asphaltenes (SARA), followed by effect-directed analyses using in vitro reporter gene assays revealed that the agonists predominantly are aromatic and resin-like chemicals. Based on study results, authors advocate an adapted risk assessment approach for complex mixtures in which low concentrations of very potent compounds are responsible for mixture effects.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/es2036948
Challenges in Sour gas handling for Kuwait Jurassic Sour Gas
SPE Middle East Unconventional Gas Conference and Exhibition, 23-25
January 2012, Abu Dhabi, UAE
Challenges in Sour gas handling for Kuwait Jurassic Sour Gas
Bader Nasser Al-Qaoud, Kuwait Oil Company
Abstract [Excerpt]
Kuwait Oil Company started free gas production from its Jurassic sour gas field in May’2008 with the commissioning of Early Production Facility EPF-50. The field produces sour gas and light crude (API: 48) from a deep High Pressure High Temperature naturally fractured carbonate reservoir of low permeability and low porosity.
Development of the Jurassic gas field is vital to the company because of its important role in meeting the domestic gas demand for the country. It has also helped to free approx. 100,000 bbls/day of crude for export which was earlier being used as fuel in the domestic power plants in Kuwait. The light crude being produced in the field is also used to blend the Kuwait export crude (KEC) and improve its API, thereby generating additional revenue for the company.
The acid gas generated in the Amine units is converted to sulphur using the Clause Process in 2 nos. of SRU’s provided in the facility. Molten sulphur produced is transported to the downstream refinery in tankers for further treatment, pellatisation and sale. A tail gas unit is also provided to ensure 99.8% conversion of the acid gas into sulphur and to meet emission norms.
Handling such highly corrosive well fluid throws up a wide range of unique challenges, from upstream, at the well head, to downstream, at the processing facility EPF-50.
Full Text Source (Subscription or Fee): http://www.onepetro.org/mslib/servlet/onepetropreview?id=SPE-154452-MS
Challenges in Sour gas handling for Kuwait Jurassic Sour Gas
Bader Nasser Al-Qaoud, Kuwait Oil Company
Abstract [Excerpt]
Kuwait Oil Company started free gas production from its Jurassic sour gas field in May’2008 with the commissioning of Early Production Facility EPF-50. The field produces sour gas and light crude (API: 48) from a deep High Pressure High Temperature naturally fractured carbonate reservoir of low permeability and low porosity.
Development of the Jurassic gas field is vital to the company because of its important role in meeting the domestic gas demand for the country. It has also helped to free approx. 100,000 bbls/day of crude for export which was earlier being used as fuel in the domestic power plants in Kuwait. The light crude being produced in the field is also used to blend the Kuwait export crude (KEC) and improve its API, thereby generating additional revenue for the company.
The acid gas generated in the Amine units is converted to sulphur using the Clause Process in 2 nos. of SRU’s provided in the facility. Molten sulphur produced is transported to the downstream refinery in tankers for further treatment, pellatisation and sale. A tail gas unit is also provided to ensure 99.8% conversion of the acid gas into sulphur and to meet emission norms.
Handling such highly corrosive well fluid throws up a wide range of unique challenges, from upstream, at the well head, to downstream, at the processing facility EPF-50.
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Multi-Stage Reforming Process With Final Stage Catalyst Regeneration
PATENT
Multi-Stage Reforming Process With Final Stage Catalyst Regeneration
United States Patent Application 20120024754
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:
12/845617
Publication Date:
02/02/2012
Assignee:
Chevron U.S.A. Inc.
Abstract:
The present invention relates to a multistage reforming process to produce a high octane product. A naphtha boiling range feedstock is processed in a multi-stage reforming process, in which said process involves at least 1) a penultimate stage for reforming the naphtha feedstock to produce a penultimate effluent 2) a final stage for further reforming at least a portion of the penultimate effluent 3) a regeneration step for the final stage catalyst. The severity of the penultimate stage can be increased during final stage catalyst regeneration in order to maintain the target RON of the reformate product and avoid reactor downtime.
RELATED APPLICATION
This application claims priority to U.S. patent application Ser. No. 12/134,153, filed Jun. 5, 2008. This application claims priority to and benefits from the foregoing, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a multistage reforming process with minimized down time during final stage catalyst regeneration. The process uses a medium pore molecular sieve catalyst in the final stage to enable fast regeneration without a halogenation step.
BACKGROUND OF THE INVENTION
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 are generally undesirable due to the low value of the resulting light hydrocarbon products.
Catalysts commonly used in commercial reforming reactions often include a Group VIII metal, such as platinum or palladium, or a Group VIII metal plus a second catalytic metal, which acts as a promoter. Examples of metals useful as promoters include rhenium, tin, tungsten, germanium, cobalt, nickel, rhodium, ruthenium, iridium or combinations thereof. The catalytic metal or metals may be dispersed on a support such as alumina, silica, or silica-alumina. Typically, a halogen such as chlorine is incorporated on the support to add acid functionality. In addition to Group VIII metals, other reforming catalysts include aluminosilicate zeolite catalysts. For example, U.S. Pat. Nos. 3,761,389, 3,756,942 and 3,760,024 teach aromatization of a hydrocarbon fraction with a ZSM-5 type zeolite catalyst. U.S. Pat. No. 4,927,525 discloses catalytic reforming processes with beta zeolite catalysts containing a noble metal and an alkali metal. Other reforming catalysts include other molecular sieves such as borosilicates and silicoaluminophosphates, layered crystalline clay-type phyllosilicates, and amorphous clays.
In addition to selection of catalysts for reforming, various processes for reforming a naphtha feedstock in one or more process steps to produce higher value reformate products are known in the art. U.S. Pat. No. 3,415,737 teaches a process for reforming naphtha under conventional mild reforming conditions with a platinum-rhenium-chloride reforming catalyst to increase the aromatics content and octane number of the naphtha. In U.S. Pat. No. 3,770,614 there is disclosed a process in which a reformate is fractionated and the light reformate fraction (C6 fraction) passed over a ZSM-5-type zeolite to increase aromatic content of the product. U.S. Pat. No. 3,950,241 discloses a process for upgrading naphtha by separating it into low- and high-boiling fractions, reforming the low-boiling fraction, combining the high-boiling naphtha with the reformate, and contacting the combined fractions with a ZSM-5-type catalyst. U.S. Pat. No. 4,181,599 discloses a process for reforming naphtha comprising separating the naphtha into heavy and light fractions and reforming and isomerizing the naphtha fractions. U.S. Pat. No. 4,190,519 teaches a process for upgrading a naphtha-boiling-range hydrocarbon which comprises separating the naphtha feedstock into a light naphtha fraction containing C6 paraffins and lower-boiling hydrocarbons and a heavy naphtha fraction containing higher-boiling hydrocarbons, reforming the heavy naphtha fraction and passing at least a portion of the reformate together with the light naphtha fraction over a zeolite catalyst to produce an aromatics-enriched effluent. Different catalysts may be employed in different process steps during the reforming of naphtha feedstocks as described in U.S. Pat. No. 4,627,909, U.S. Pat. No. 4,443,326, U.S. Pat. No. 4,764,267, U.S. Pat. No. 5,073,250, U.S. Pat. No. 5,169,813, U.S. Pat. No. 5,171,691, U.S. Pat. No. 5,182,012, U.S. Pat. No. 5,358,631, U.S. Pat. No. 5,376,259 and U.S. Pat. No. 5,407,558, for example.
Even with the advances in naphtha reforming catalysts and processes, a need still exists to develop new and improved reforming methods to provide higher liquid yield, improve hydrogen production, and minimize the formation of less valuable low molecule weight (C1-C4) products. It has been discovered that interstage feed separation in a staged reforming process and lower pressure in the final stage of a multistage reforming process can improve the RON (Research Octane Number), aromatics content, C5+ liquid yield, hydrogen production, and catalyst life.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that in a multi-stage reforming process, the yield of hydrocarbon product and hydrogen can be optimized by increasing the severity of the penultimate stage during regeneration of the final stage catalyst. During regeneration of the final stage catalyst, the RON of the effluent from the penultimate stage can meet the target RON of the hydrocarbon product by temporarily increasing the severity of the penultimate stage reaction conditions. Due to fast regeneration times of the final stage catalyst, the lifetime of the penultimate stage catalyst is minimally affected by the increased reaction severity.
The present invention relates to processes for catalytically reforming a naphtha feed to produce a product reformate in a multistage reforming operation. The reforming process includes providing a naphtha to a multi-stage reforming system that includes a penultimate reforming stage containing a first reforming catalyst and a final reforming stage containing a second reforming catalyst; contacting the naphtha at a first reforming temperature with the first reforming catalyst and producing a penultimate effluent; contacting at least a portion of the penultimate effluent at a second reforming temperature with the second reforming catalyst and producing a final reformate having an RON of greater than 90; and regenerating the second reforming catalyst in the final reforming stage while reforming the naphtha in the penultimate reforming stage and producing a third reformate from the penultimate reforming stage that has an RON of at least 90.
In embodiments, the first reforming catalyst includes platinum and rhenium on an alumina support. In embodiments, the second reforming catalyst includes silicalite having a silica to alumina molar ratio of at least 200, a crystallite size of less than 10 microns and an alkali content of less than 5,000 ppm.
In embodiments, the step of regenerating the second reforming catalyst includes ceasing the flow of intermediate reformate to the final reforming stage; increasing the reforming temperature in the penultimate reforming stage by at least 5° F. (2.8° C.) to produce a third reformate having an RON of at least 90; and regenerating the second reforming catalyst in the final reforming stage. In further embodiments, the step of regenerating the second reforming catalyst includes passing a nitrogen containing stream through the second reforming stage to remove at least a portion of the naphtha container therein; passing an oxygen containing stream through the final reforming stage to remove at least a portion of the carbon deposited on the second reforming catalyst contained within the final reforming stage; passing a nitrogen containing stream through the second reforming catalyst to remove at least a portion of the oxygen contained therein; reducing the temperature of the second reforming catalyst within the final reforming stage to a temperature of less than the second reforming temperature; introducing at least a portion of the penultimate effluent to the final reforming stage; and increasing the temperature of the second reforming catalyst to a temperature in the range of 800° F. to 1100° F. (427° C.-593° C.). In further embodiments, the step of regenerating the second reforming catalyst includes reducing the reforming temperature in the penultimate reforming stage by at least 5° F. (2.8° C.).
Other aspects, features and advantages will be apparent from the description of the embodiments thereof and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of one embodiment of the invention.
FIG. 2 is a schematic diagram of a second embodiment of the invention.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0024754.html
Multi-Stage Reforming Process With Final Stage Catalyst Regeneration
United States Patent Application 20120024754
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:
12/845617
Publication Date:
02/02/2012
Assignee:
Chevron U.S.A. Inc.
Abstract:
The present invention relates to a multistage reforming process to produce a high octane product. A naphtha boiling range feedstock is processed in a multi-stage reforming process, in which said process involves at least 1) a penultimate stage for reforming the naphtha feedstock to produce a penultimate effluent 2) a final stage for further reforming at least a portion of the penultimate effluent 3) a regeneration step for the final stage catalyst. The severity of the penultimate stage can be increased during final stage catalyst regeneration in order to maintain the target RON of the reformate product and avoid reactor downtime.
RELATED APPLICATION
This application claims priority to U.S. patent application Ser. No. 12/134,153, filed Jun. 5, 2008. This application claims priority to and benefits from the foregoing, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a multistage reforming process with minimized down time during final stage catalyst regeneration. The process uses a medium pore molecular sieve catalyst in the final stage to enable fast regeneration without a halogenation step.
BACKGROUND OF THE INVENTION
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 are generally undesirable due to the low value of the resulting light hydrocarbon products.
Catalysts commonly used in commercial reforming reactions often include a Group VIII metal, such as platinum or palladium, or a Group VIII metal plus a second catalytic metal, which acts as a promoter. Examples of metals useful as promoters include rhenium, tin, tungsten, germanium, cobalt, nickel, rhodium, ruthenium, iridium or combinations thereof. The catalytic metal or metals may be dispersed on a support such as alumina, silica, or silica-alumina. Typically, a halogen such as chlorine is incorporated on the support to add acid functionality. In addition to Group VIII metals, other reforming catalysts include aluminosilicate zeolite catalysts. For example, U.S. Pat. Nos. 3,761,389, 3,756,942 and 3,760,024 teach aromatization of a hydrocarbon fraction with a ZSM-5 type zeolite catalyst. U.S. Pat. No. 4,927,525 discloses catalytic reforming processes with beta zeolite catalysts containing a noble metal and an alkali metal. Other reforming catalysts include other molecular sieves such as borosilicates and silicoaluminophosphates, layered crystalline clay-type phyllosilicates, and amorphous clays.
In addition to selection of catalysts for reforming, various processes for reforming a naphtha feedstock in one or more process steps to produce higher value reformate products are known in the art. U.S. Pat. No. 3,415,737 teaches a process for reforming naphtha under conventional mild reforming conditions with a platinum-rhenium-chloride reforming catalyst to increase the aromatics content and octane number of the naphtha. In U.S. Pat. No. 3,770,614 there is disclosed a process in which a reformate is fractionated and the light reformate fraction (C6 fraction) passed over a ZSM-5-type zeolite to increase aromatic content of the product. U.S. Pat. No. 3,950,241 discloses a process for upgrading naphtha by separating it into low- and high-boiling fractions, reforming the low-boiling fraction, combining the high-boiling naphtha with the reformate, and contacting the combined fractions with a ZSM-5-type catalyst. U.S. Pat. No. 4,181,599 discloses a process for reforming naphtha comprising separating the naphtha into heavy and light fractions and reforming and isomerizing the naphtha fractions. U.S. Pat. No. 4,190,519 teaches a process for upgrading a naphtha-boiling-range hydrocarbon which comprises separating the naphtha feedstock into a light naphtha fraction containing C6 paraffins and lower-boiling hydrocarbons and a heavy naphtha fraction containing higher-boiling hydrocarbons, reforming the heavy naphtha fraction and passing at least a portion of the reformate together with the light naphtha fraction over a zeolite catalyst to produce an aromatics-enriched effluent. Different catalysts may be employed in different process steps during the reforming of naphtha feedstocks as described in U.S. Pat. No. 4,627,909, U.S. Pat. No. 4,443,326, U.S. Pat. No. 4,764,267, U.S. Pat. No. 5,073,250, U.S. Pat. No. 5,169,813, U.S. Pat. No. 5,171,691, U.S. Pat. No. 5,182,012, U.S. Pat. No. 5,358,631, U.S. Pat. No. 5,376,259 and U.S. Pat. No. 5,407,558, for example.
Even with the advances in naphtha reforming catalysts and processes, a need still exists to develop new and improved reforming methods to provide higher liquid yield, improve hydrogen production, and minimize the formation of less valuable low molecule weight (C1-C4) products. It has been discovered that interstage feed separation in a staged reforming process and lower pressure in the final stage of a multistage reforming process can improve the RON (Research Octane Number), aromatics content, C5+ liquid yield, hydrogen production, and catalyst life.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that in a multi-stage reforming process, the yield of hydrocarbon product and hydrogen can be optimized by increasing the severity of the penultimate stage during regeneration of the final stage catalyst. During regeneration of the final stage catalyst, the RON of the effluent from the penultimate stage can meet the target RON of the hydrocarbon product by temporarily increasing the severity of the penultimate stage reaction conditions. Due to fast regeneration times of the final stage catalyst, the lifetime of the penultimate stage catalyst is minimally affected by the increased reaction severity.
The present invention relates to processes for catalytically reforming a naphtha feed to produce a product reformate in a multistage reforming operation. The reforming process includes providing a naphtha to a multi-stage reforming system that includes a penultimate reforming stage containing a first reforming catalyst and a final reforming stage containing a second reforming catalyst; contacting the naphtha at a first reforming temperature with the first reforming catalyst and producing a penultimate effluent; contacting at least a portion of the penultimate effluent at a second reforming temperature with the second reforming catalyst and producing a final reformate having an RON of greater than 90; and regenerating the second reforming catalyst in the final reforming stage while reforming the naphtha in the penultimate reforming stage and producing a third reformate from the penultimate reforming stage that has an RON of at least 90.
In embodiments, the first reforming catalyst includes platinum and rhenium on an alumina support. In embodiments, the second reforming catalyst includes silicalite having a silica to alumina molar ratio of at least 200, a crystallite size of less than 10 microns and an alkali content of less than 5,000 ppm.
In embodiments, the step of regenerating the second reforming catalyst includes ceasing the flow of intermediate reformate to the final reforming stage; increasing the reforming temperature in the penultimate reforming stage by at least 5° F. (2.8° C.) to produce a third reformate having an RON of at least 90; and regenerating the second reforming catalyst in the final reforming stage. In further embodiments, the step of regenerating the second reforming catalyst includes passing a nitrogen containing stream through the second reforming stage to remove at least a portion of the naphtha container therein; passing an oxygen containing stream through the final reforming stage to remove at least a portion of the carbon deposited on the second reforming catalyst contained within the final reforming stage; passing a nitrogen containing stream through the second reforming catalyst to remove at least a portion of the oxygen contained therein; reducing the temperature of the second reforming catalyst within the final reforming stage to a temperature of less than the second reforming temperature; introducing at least a portion of the penultimate effluent to the final reforming stage; and increasing the temperature of the second reforming catalyst to a temperature in the range of 800° F. to 1100° F. (427° C.-593° C.). In further embodiments, the step of regenerating the second reforming catalyst includes reducing the reforming temperature in the penultimate reforming stage by at least 5° F. (2.8° C.).
Other aspects, features and advantages will be apparent from the description of the embodiments thereof and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of one embodiment of the invention.
FIG. 2 is a schematic diagram of a second embodiment of the invention.
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Multi-Stage Hydroprocessing for the Production of High Octane Naphtha
PATENT
Multi-Stage Hydroprocessing for the Production of High Octane Naphtha
United States Patent Application 20120024752
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:
12/845605
Publication Date:
02/02/2012
Assignee:
Chevron U.S.A. Inc.
Abstract:
An integrated process is provided for producing high octane naphtha. Hydrocracked naphtha from a hydrocracking reaction zone is contacted with a reforming catalyst that includes a silicate having a silica to alumina molar ratio of at least 200, and a crystallite size of less than 10 microns. Products from the reforming include a reformed naphtha and a hydrogen-rich stream, which is passed to the hydrocracking reaction zone.
FIELD OF THE INVENTION
The present invention provides a multi-stage integrated process for the production of high octane naphtha from a hydrocarbonaceous feedstock.
BACKGROUND
Different processes exist for upgrading hydrocarbonaceous feedstocks. As the demand for transportation fuels such as gasoline, diesel, and jet fuel grows, processes for upgrading low grade distillates and residuum are becoming increasingly important. Hydroprocessing reactions such as hydrotreating, hydrocracking, and reforming use catalysts to upgrade various feedstocks. Because heteroatoms can damage hydrocracking and/or reforming catalysts they are generally removed prior to hydrocracking and/or reforming by hydrotreating. Hydrotreating removes nitrogen, sulfur, and other impurities in hydrocarbon feedstocks. Subsequently, these feedstocks can be used in other refinery processes such as hydrocracking and reforming. In hydrocracking, heavy feedstocks including low grade distillates and gas oils with high molecular weights are converted to lower molecular weight effluents such as naphthas. Large amounts of hydrogen are consumed in typical hydrocracking processes. Reforming is used for upgrading light hydrocarbon feedstocks such as naphthas. 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 dehydrocyclization, 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.
Many refinery processes use a combination of hydroprocessing reactions to upgrade heavy feedstocks. For example, in an initial stage, the feedstock can be hydrotreated to reduce the amount of heteroatoms which can have a deleterious effect on downstream hydrocracking and/or reforming catalysts. The multistage process can use a common hydrogen supply system as disclosed in, for example, U.S. Pat. No. 5,009,768. Other U.S. patents which are directed to multistage hydroprocessing within a single high pressure hydrogen loop include, for example, U.S. Pat. No. 6,797,154. In this patent high conversion of heavy gas oils and the production of high quality middle distillate products are possible in a single high-pressure loop with reaction stages operating at different pressure and conversion levels. The flexibility offered is great and allows the refiner to avoid decreases in product quality while at the same time minimizing capital cost. Feeds with varying boiling ranges are introduced at different sections of the process, thereby minimizing the consumption of hydrogen and reducing capital investment.
U.S. Pat. No. 6,787,025 also discloses multi-stage hydroprocessing for the production of middle distillates. A major benefit of this invention is the potential for simultaneously upgrading difficult cracked stocks such as Light Cycle Oil, Light Coker Gas Oil, Visbroken Gas Oil, and/or Straight-Run Atmospheric Gas Oils utilizing the high-pressure environment required for mild hydrocracking.
U.S. Pat. No. 7,238,277 provides very high to total conversion of heavy oils to products in a single high-pressure loop, using multiple reaction stages. The second stage or subsequent stages may be a combination of co-current and counter-current operation. The benefits of this invention include conversion of feed to useful products at reduced operating pressures using lower catalyst volumes. Lower hydrogen consumption also results.
U.S. Publication 20050103682 relates to a multi-stage process for hydroprocessing gas oils. Preferably, each stage possesses at least one hydrocracking zone. The second stage and any subsequent stages possess an environment having a low heteroatom content. Light products, such as naphtha, kerosene and diesel, may be recycled from fractionation (along with light products from other sources) to the second stage (or a subsequent stage) in order to produce a larger yield of lighter products, such as gas and naphtha. Pressure in the zone or zones subsequent to the initial zone is from 500 to 1000 psig lower than the pressure in the initial zone, in order to provide cost savings and minimize overcracking.
Catalytic reforming is a well-known refinery process for upgrading light hydrocarbon feedstocks, frequently referred to as naphtha feedstocks. Products from catalytic reforming can include high octane gasoline, useful as automobile fuel, and/or aromatics, such as benzene and toluene, useful as chemicals. Reactions typically involved in catalytic reforming include dehydrocyclization, isomerization and dehydrogenation. Dehydrocyclization is a well known reaction wherein alkanes are converted to aromatics. For example, hexane may be dehydrocyclized to benzene. Thus, reforming typically includes dehydrocyclization. However, dehydrocyclization or aromatization of alkanes can be directed more narrowly than reforming.
Even with the advances in hydroprocessing catalysts and processes, a need still exists to develop new and improved methods to provide high liquid yield of valuable gasoline, diesel, and jet fuel products, improve hydrogen production, and minimize the formation of less valuable low molecule weight (C1-C4) products. Thus, further improvements for reducing refinery operating costs by maximizing the production of valuable high octane products from low grade feedstocks and minimizing the amount of hydrogen needed during the hydroprocessing reactions are desirable.
SUMMARY OF THE INVENTION
Accordingly, a process is provided for producing high octane naphtha, including (a) isolating a hydrocracked naphtha from a hydrocracking reaction zone effluent; (b) providing at least a portion of the hydrocracked naphtha to a reforming reaction zone containing a reforming catalyst containing a silicate having a silica to alumina molar ratio of at least 200, and a crystallite size of less than 10 microns; (c) contacting the at least a portion of the hydrocracked naphtha with the reforming catalyst at reforming reaction conditions and producing a hydrogen-rich stream and a reformed naphtha; and (d) passing the hydrogen-rich stream to the hydrocracking reaction zone.
In embodiments, the hydrocracked naphtha contains at least 70 wt % C4 to C10 hydrocarbons, and has an octane of less than 90. In embodiments, the reformed naphtha includes at least 70 wt % C5 to C9 hydrocarbons, and has an octane of greater than 95.
In embodiments, at least a portion of the hydrocracked naphtha and at least a portion of the reformed naphtha are blended as a combined naphtha, to be used as a fuel or fuel blendstock.
In embodiments, reformer reaction conditions include a pressure in the range of between 0 psig and 250 psig, a temperature in the range of between 600° and 1100° F. and a liquid feed rate in the range of between 0.1 and 20 hr−1.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0024752.html
Multi-Stage Hydroprocessing for the Production of High Octane Naphtha
United States Patent Application 20120024752
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:
12/845605
Publication Date:
02/02/2012
Assignee:
Chevron U.S.A. Inc.
Abstract:
An integrated process is provided for producing high octane naphtha. Hydrocracked naphtha from a hydrocracking reaction zone is contacted with a reforming catalyst that includes a silicate having a silica to alumina molar ratio of at least 200, and a crystallite size of less than 10 microns. Products from the reforming include a reformed naphtha and a hydrogen-rich stream, which is passed to the hydrocracking reaction zone.
FIELD OF THE INVENTION
The present invention provides a multi-stage integrated process for the production of high octane naphtha from a hydrocarbonaceous feedstock.
BACKGROUND
Different processes exist for upgrading hydrocarbonaceous feedstocks. As the demand for transportation fuels such as gasoline, diesel, and jet fuel grows, processes for upgrading low grade distillates and residuum are becoming increasingly important. Hydroprocessing reactions such as hydrotreating, hydrocracking, and reforming use catalysts to upgrade various feedstocks. Because heteroatoms can damage hydrocracking and/or reforming catalysts they are generally removed prior to hydrocracking and/or reforming by hydrotreating. Hydrotreating removes nitrogen, sulfur, and other impurities in hydrocarbon feedstocks. Subsequently, these feedstocks can be used in other refinery processes such as hydrocracking and reforming. In hydrocracking, heavy feedstocks including low grade distillates and gas oils with high molecular weights are converted to lower molecular weight effluents such as naphthas. Large amounts of hydrogen are consumed in typical hydrocracking processes. Reforming is used for upgrading light hydrocarbon feedstocks such as naphthas. 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 dehydrocyclization, 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.
Many refinery processes use a combination of hydroprocessing reactions to upgrade heavy feedstocks. For example, in an initial stage, the feedstock can be hydrotreated to reduce the amount of heteroatoms which can have a deleterious effect on downstream hydrocracking and/or reforming catalysts. The multistage process can use a common hydrogen supply system as disclosed in, for example, U.S. Pat. No. 5,009,768. Other U.S. patents which are directed to multistage hydroprocessing within a single high pressure hydrogen loop include, for example, U.S. Pat. No. 6,797,154. In this patent high conversion of heavy gas oils and the production of high quality middle distillate products are possible in a single high-pressure loop with reaction stages operating at different pressure and conversion levels. The flexibility offered is great and allows the refiner to avoid decreases in product quality while at the same time minimizing capital cost. Feeds with varying boiling ranges are introduced at different sections of the process, thereby minimizing the consumption of hydrogen and reducing capital investment.
U.S. Pat. No. 6,787,025 also discloses multi-stage hydroprocessing for the production of middle distillates. A major benefit of this invention is the potential for simultaneously upgrading difficult cracked stocks such as Light Cycle Oil, Light Coker Gas Oil, Visbroken Gas Oil, and/or Straight-Run Atmospheric Gas Oils utilizing the high-pressure environment required for mild hydrocracking.
U.S. Pat. No. 7,238,277 provides very high to total conversion of heavy oils to products in a single high-pressure loop, using multiple reaction stages. The second stage or subsequent stages may be a combination of co-current and counter-current operation. The benefits of this invention include conversion of feed to useful products at reduced operating pressures using lower catalyst volumes. Lower hydrogen consumption also results.
U.S. Publication 20050103682 relates to a multi-stage process for hydroprocessing gas oils. Preferably, each stage possesses at least one hydrocracking zone. The second stage and any subsequent stages possess an environment having a low heteroatom content. Light products, such as naphtha, kerosene and diesel, may be recycled from fractionation (along with light products from other sources) to the second stage (or a subsequent stage) in order to produce a larger yield of lighter products, such as gas and naphtha. Pressure in the zone or zones subsequent to the initial zone is from 500 to 1000 psig lower than the pressure in the initial zone, in order to provide cost savings and minimize overcracking.
Catalytic reforming is a well-known refinery process for upgrading light hydrocarbon feedstocks, frequently referred to as naphtha feedstocks. Products from catalytic reforming can include high octane gasoline, useful as automobile fuel, and/or aromatics, such as benzene and toluene, useful as chemicals. Reactions typically involved in catalytic reforming include dehydrocyclization, isomerization and dehydrogenation. Dehydrocyclization is a well known reaction wherein alkanes are converted to aromatics. For example, hexane may be dehydrocyclized to benzene. Thus, reforming typically includes dehydrocyclization. However, dehydrocyclization or aromatization of alkanes can be directed more narrowly than reforming.
Even with the advances in hydroprocessing catalysts and processes, a need still exists to develop new and improved methods to provide high liquid yield of valuable gasoline, diesel, and jet fuel products, improve hydrogen production, and minimize the formation of less valuable low molecule weight (C1-C4) products. Thus, further improvements for reducing refinery operating costs by maximizing the production of valuable high octane products from low grade feedstocks and minimizing the amount of hydrogen needed during the hydroprocessing reactions are desirable.
SUMMARY OF THE INVENTION
Accordingly, a process is provided for producing high octane naphtha, including (a) isolating a hydrocracked naphtha from a hydrocracking reaction zone effluent; (b) providing at least a portion of the hydrocracked naphtha to a reforming reaction zone containing a reforming catalyst containing a silicate having a silica to alumina molar ratio of at least 200, and a crystallite size of less than 10 microns; (c) contacting the at least a portion of the hydrocracked naphtha with the reforming catalyst at reforming reaction conditions and producing a hydrogen-rich stream and a reformed naphtha; and (d) passing the hydrogen-rich stream to the hydrocracking reaction zone.
In embodiments, the hydrocracked naphtha contains at least 70 wt % C4 to C10 hydrocarbons, and has an octane of less than 90. In embodiments, the reformed naphtha includes at least 70 wt % C5 to C9 hydrocarbons, and has an octane of greater than 95.
In embodiments, at least a portion of the hydrocracked naphtha and at least a portion of the reformed naphtha are blended as a combined naphtha, to be used as a fuel or fuel blendstock.
In embodiments, reformer reaction conditions include a pressure in the range of between 0 psig and 250 psig, a temperature in the range of between 600° and 1100° F. and a liquid feed rate in the range of between 0.1 and 20 hr−1.
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Hydrodechlorination Of Ionic Liquid-Derived Hydrocarbon Products
PATENT
Hydrodechlorination Of Ionic Liquid-Derived Hydrocarbon Products
United States Patent Application 20120024750
Inventors:
Zhan, Bi-zeng (Albany, CA, US)
Timken, Hye Kyung (Albany, CA, US)
He, Zunqing (San Rafael, CA, US)
Cooper, Russell (Fairfield, CA, US)
Application Number: 12/847313
Publication Date: 02/02/2012
Assignee: Chevron U.S.A. Inc.
Abstract
Processes for the hydrodechlorination of one or more hydrocarbon products derived from ionic liquid catalyzed hydrocarbon conversion reactions provide a dechlorinated product and an HCl-containing off-gas. The dechlorinated product provides liquid fuel or lubricating base oil, and the HCl may be recovered from the off-gas for recycling to the ionic liquid catalyzed hydrocarbon conversion reaction as a catalyst promoter.
TECHNICAL FIELD
The present invention relates to hydrodechlorination of ionic liquid derived hydrocarbon products.
BACKGROUND
The conversion by refining industries of light paraffins and light olefins to more valuable cuts has been accomplished by the alkylation of paraffins with olefins and by the polymerization of olefins. Such processes, which have been used since the 1940's, continue to be driven by the increasing demand for high quality and clean burning high-octane gasoline, distillate and lubricating base oil.
Conventional alkylation processes use vast quantities of H2SO4 or HF as catalyst. The quest for an alternative catalytic system to replace the conventional catalysts has been researched by various groups in both academic and industrial institutions. Unfortunately, thus far, no viable replacement to the conventional processes has been commercialized.
Recently there has been considerable interest in metal halide ionic liquid catalysts as alternatives to conventional catalysts. As an example, the ionic liquid catalyzed alkylation of isoparaffins with olefins is disclosed in U.S. Pat. No. 7,432,408 to Timken et al. U.S. Pat. No. 7,572,943 to Elomari et al. discloses the ionic liquid catalyzed oligomerization of olefins and the alkylation of the resulting oligomers(s) with isoparaffins to produce alkylated olefin oligomers. The presence of HCl as a co-catalyst with an ionic liquid provides an increased level of catalytic activity, for example, as disclosed by the '408 patent. Typically, anhydrous HCl or organic chloride may be combined with the ionic liquid feed to attain the desired level of catalytic activity and selectivity (see, e.g., U.S. Pat. No. 7,495,144 to Elomari, and U.S. Pat. No. 7,531,707 to Harris et al.). When organic chloride is used as the co-catalyst with the ionic liquid, HCl may be formed in situ in the reactor during the hydrocarbon conversion process.
Hydrocarbon product(s) of ionic liquid catalyzed hydrocarbon conversions, such as alkylate or distillate or base oil, typically contain substantial amounts of organic chloride components that are produced during the reaction. The removal of organic chloride components from such hydrocarbon product(s) may be desirable, e.g., to prevent the formation of unwanted by-products during combustion of liquid fuels (see, for example, U.S. Pat. No. 7,538,256 to Driver et al., the disclosure of which is incorporated by reference herein in its entirety).
There is a need for processes for the efficient dechlorination of hydrocarbon products derived from ionic liquid catalyzed hydrocarbon conversion reactions. There is a further need for the removal of HCl from hydrodechlorination off-gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A represents a scheme for a combined hydrocarbon conversion, hydrodechlorination, and hydrogen chloride recovery process, according to an embodiment of the present invention;
FIG. 1B represents a scheme for a combined hydrocarbon conversion, hydrodechlorination, and hydrogen chloride recovery process, according to another embodiment of the present invention;
FIG. 2 shows the boiling point distribution of a hydrodechlorinated alkylate product, as compared with a chlorinated alkylate feed, according to an embodiment of the present invention; and
FIG. 3 shows an HCl breakthrough curve by contacting an HCl-containing off-gas from the hydrodechlorination of an alkylate distillate with an adsorbent comprising zeolite 4A.
SUMMARY
The present invention provides processes for the hydrodechlorination of hydrocarbon products derived from ionic liquid catalyzed hydrocarbon conversion reactions. The present invention also provides processes for the recovery of HCl obtained from hydrodechlorination off-gas. The present invention further provides an integrated hydrocarbon conversion, hydrodechlorination, and HCl recovery process, wherein HCl that is recovered from dechlorination processes may be used as a catalyst promoter for the ionic liquid catalyzed hydrocarbon conversion reactions.
According to one aspect of the present invention there is provided an integrated hydrocarbon conversion process comprising contacting at least one hydrocarbon reactant with an ionic liquid catalyst in a hydrocarbon conversion zone under hydrocarbon conversion conditions to provide at least one hydrocarbon product comprising at least one halogenated component; and contacting the at least one hydrocarbon product with a hydrodechlorination catalyst in the presence of hydrogen in a hydrodechlorination zone under hydrodechlorination conditions to provide: i) a dechlorinated product, and ii) an off-gas comprising HCl. A first chloride content of the at least one hydrocarbon product may be greater than 50 ppm, the chloride content of the dechlorinated product is lower than the feed, to be less than 50 ppm, and typically less than 10 ppm.
In an embodiment, the present invention also provides a hydrogen chloride recovery process comprising contacting at least one hydrocarbon product with a hydrodechlorination catalyst in the presence of hydrogen under hydrodechlorination conditions to provide: i) an off-gas comprising HCl, and ii) a dechlorinated product; separating the dechlorinated product from the off-gas; contacting the off-gas with an adsorbent under HCl adsorbing conditions such that the HCl is adsorbed by the adsorbent; and, after the prior step, recovering the HCl from the adsorbent. The dechlorinated product may comprise alkylate gasoline, jet fuel, diesel fuel, base oil, or a combination thereof.
In another embodiment, the present invention further provides a hydrocarbon conversion and hydrodechlorination process comprising contacting at least one hydrocarbon reactant with an ionic liquid catalyst in a hydrocarbon conversion zone under hydrocarbon conversion conditions to provide used ionic liquid combined with conjunct polymer; regenerating at least a portion of the used ionic liquid in a catalyst regeneration zone to provide reactivated ionic liquid catalyst and free conjunct polymer; after the prior step, separating the conjunct polymer from the ionic liquid catalyst; and after the prior step, contacting the separated conjunct polymer with a hydrodechlorination catalyst in the presence of hydrogen in a hydrodechlorination zone under hydrodechlorination conditions to provide a dechlorinated product.
As used herein, the terms “comprising” and “comprises” mean the inclusion of named elements or steps that are identified following those terms, but not necessarily excluding other unnamed elements or steps.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0024750.html
Hydrodechlorination Of Ionic Liquid-Derived Hydrocarbon Products
United States Patent Application 20120024750
Inventors:
Zhan, Bi-zeng (Albany, CA, US)
Timken, Hye Kyung (Albany, CA, US)
He, Zunqing (San Rafael, CA, US)
Cooper, Russell (Fairfield, CA, US)
Application Number: 12/847313
Publication Date: 02/02/2012
Assignee: Chevron U.S.A. Inc.
Abstract
Processes for the hydrodechlorination of one or more hydrocarbon products derived from ionic liquid catalyzed hydrocarbon conversion reactions provide a dechlorinated product and an HCl-containing off-gas. The dechlorinated product provides liquid fuel or lubricating base oil, and the HCl may be recovered from the off-gas for recycling to the ionic liquid catalyzed hydrocarbon conversion reaction as a catalyst promoter.
TECHNICAL FIELD
The present invention relates to hydrodechlorination of ionic liquid derived hydrocarbon products.
BACKGROUND
The conversion by refining industries of light paraffins and light olefins to more valuable cuts has been accomplished by the alkylation of paraffins with olefins and by the polymerization of olefins. Such processes, which have been used since the 1940's, continue to be driven by the increasing demand for high quality and clean burning high-octane gasoline, distillate and lubricating base oil.
Conventional alkylation processes use vast quantities of H2SO4 or HF as catalyst. The quest for an alternative catalytic system to replace the conventional catalysts has been researched by various groups in both academic and industrial institutions. Unfortunately, thus far, no viable replacement to the conventional processes has been commercialized.
Recently there has been considerable interest in metal halide ionic liquid catalysts as alternatives to conventional catalysts. As an example, the ionic liquid catalyzed alkylation of isoparaffins with olefins is disclosed in U.S. Pat. No. 7,432,408 to Timken et al. U.S. Pat. No. 7,572,943 to Elomari et al. discloses the ionic liquid catalyzed oligomerization of olefins and the alkylation of the resulting oligomers(s) with isoparaffins to produce alkylated olefin oligomers. The presence of HCl as a co-catalyst with an ionic liquid provides an increased level of catalytic activity, for example, as disclosed by the '408 patent. Typically, anhydrous HCl or organic chloride may be combined with the ionic liquid feed to attain the desired level of catalytic activity and selectivity (see, e.g., U.S. Pat. No. 7,495,144 to Elomari, and U.S. Pat. No. 7,531,707 to Harris et al.). When organic chloride is used as the co-catalyst with the ionic liquid, HCl may be formed in situ in the reactor during the hydrocarbon conversion process.
Hydrocarbon product(s) of ionic liquid catalyzed hydrocarbon conversions, such as alkylate or distillate or base oil, typically contain substantial amounts of organic chloride components that are produced during the reaction. The removal of organic chloride components from such hydrocarbon product(s) may be desirable, e.g., to prevent the formation of unwanted by-products during combustion of liquid fuels (see, for example, U.S. Pat. No. 7,538,256 to Driver et al., the disclosure of which is incorporated by reference herein in its entirety).
There is a need for processes for the efficient dechlorination of hydrocarbon products derived from ionic liquid catalyzed hydrocarbon conversion reactions. There is a further need for the removal of HCl from hydrodechlorination off-gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A represents a scheme for a combined hydrocarbon conversion, hydrodechlorination, and hydrogen chloride recovery process, according to an embodiment of the present invention;
FIG. 1B represents a scheme for a combined hydrocarbon conversion, hydrodechlorination, and hydrogen chloride recovery process, according to another embodiment of the present invention;
FIG. 2 shows the boiling point distribution of a hydrodechlorinated alkylate product, as compared with a chlorinated alkylate feed, according to an embodiment of the present invention; and
FIG. 3 shows an HCl breakthrough curve by contacting an HCl-containing off-gas from the hydrodechlorination of an alkylate distillate with an adsorbent comprising zeolite 4A.
SUMMARY
The present invention provides processes for the hydrodechlorination of hydrocarbon products derived from ionic liquid catalyzed hydrocarbon conversion reactions. The present invention also provides processes for the recovery of HCl obtained from hydrodechlorination off-gas. The present invention further provides an integrated hydrocarbon conversion, hydrodechlorination, and HCl recovery process, wherein HCl that is recovered from dechlorination processes may be used as a catalyst promoter for the ionic liquid catalyzed hydrocarbon conversion reactions.
According to one aspect of the present invention there is provided an integrated hydrocarbon conversion process comprising contacting at least one hydrocarbon reactant with an ionic liquid catalyst in a hydrocarbon conversion zone under hydrocarbon conversion conditions to provide at least one hydrocarbon product comprising at least one halogenated component; and contacting the at least one hydrocarbon product with a hydrodechlorination catalyst in the presence of hydrogen in a hydrodechlorination zone under hydrodechlorination conditions to provide: i) a dechlorinated product, and ii) an off-gas comprising HCl. A first chloride content of the at least one hydrocarbon product may be greater than 50 ppm, the chloride content of the dechlorinated product is lower than the feed, to be less than 50 ppm, and typically less than 10 ppm.
In an embodiment, the present invention also provides a hydrogen chloride recovery process comprising contacting at least one hydrocarbon product with a hydrodechlorination catalyst in the presence of hydrogen under hydrodechlorination conditions to provide: i) an off-gas comprising HCl, and ii) a dechlorinated product; separating the dechlorinated product from the off-gas; contacting the off-gas with an adsorbent under HCl adsorbing conditions such that the HCl is adsorbed by the adsorbent; and, after the prior step, recovering the HCl from the adsorbent. The dechlorinated product may comprise alkylate gasoline, jet fuel, diesel fuel, base oil, or a combination thereof.
In another embodiment, the present invention further provides a hydrocarbon conversion and hydrodechlorination process comprising contacting at least one hydrocarbon reactant with an ionic liquid catalyst in a hydrocarbon conversion zone under hydrocarbon conversion conditions to provide used ionic liquid combined with conjunct polymer; regenerating at least a portion of the used ionic liquid in a catalyst regeneration zone to provide reactivated ionic liquid catalyst and free conjunct polymer; after the prior step, separating the conjunct polymer from the ionic liquid catalyst; and after the prior step, contacting the separated conjunct polymer with a hydrodechlorination catalyst in the presence of hydrogen in a hydrodechlorination zone under hydrodechlorination conditions to provide a dechlorinated product.
As used herein, the terms “comprising” and “comprises” mean the inclusion of named elements or steps that are identified following those terms, but not necessarily excluding other unnamed elements or steps.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0024750.html
Multi-Stage Reforming Process To Produce High Octane Gasoline
PATENT
Multi-Stage Reforming Process To Produce High Octane Gasoline
United States Patent Application 20120024753
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:
12/845615
Publication Date:
02/02/2012
Assignee:
Chevron U.S.A. Inc.
Abstract:
The present invention relates to a multistage reforming process to produce a high octane product. A naphtha boiling range feedstock is processed in a multi-stage reforming process, in which said process involves at least 1) a penultimate stage for reforming the naphtha feedstock to produce a penultimate effluent 2) a final stage for further reforming at least a portion of the penultimate effluent 3) a regeneration step for the final stage catalyst. The severity of the penultimate stage can be increased during final stage catalyst regeneration in order to maintain the target RON of the reformate product and avoid reactor downtime.
FIELD OF THE INVENTION
The present invention relates to a multistage naphtha reforming process using an interstage separation step to produce a high octane product at high liquid yield and hydrogen production.
BACKGROUND OF THE INVENTION
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 are generally undesirable due to the low value of the resulting light hydrocarbon products.
Catalysts commonly used in commercial reforming reactions often include a Group VIII metal, such as platinum or palladium, or a Group VIII metal plus a second catalytic metal, which acts as a promoter. Examples of metals useful as promoters include rhenium, tin, tungsten, germanium, cobalt, nickel, rhodium, ruthenium, iridium or combinations thereof. The catalytic metal or metals may be dispersed on a support such as alumina, silica, or silica-alumina. Typically, a halogen such as chlorine is incorporated on the support to add acid functionality. In addition to Group VIII metals, other reforming catalysts include aluminosilicate zeolite catalysts. For example, U.S. Pat. Nos. 3,761,389, 3,756,942 and 3,760,024 teach aromatization of a hydrocarbon fraction with a ZSM-5 type zeolite catalyst. U.S. Pat. No. 4,927,525 discloses catalytic reforming processes with beta zeolite catalysts containing a noble metal and an alkali metal. Other reforming catalysts include other molecular sieves such as borosilicates and silicoaluminophosphates, layered crystalline clay-type phyllosilicates, and amorphous clays.
In addition to selection of catalysts for reforming, various processes for reforming a naphtha feedstock in one or more process steps to produce higher value reformate products are known in the art. U.S. Pat. No. 3,415,737 teaches a process for reforming naphtha under conventional mild reforming conditions with a platinum-rhenium-chloride reforming catalyst to increase the aromatics content and octane number of the naphtha. In U.S. Pat. No. 3,770,614 there is disclosed a process in which a reformate is fractionated and the light reformate fraction (C6 fraction) passed over a ZSM-5-type zeolite to increase aromatic content of the product. U.S. Pat. No. 3,950,241 discloses a process for upgrading naphtha by separating it into low- and high-boiling fractions, reforming the low-boiling fraction, combining the high-boiling naphtha with the reformate, and contacting the combined fractions with a ZSM-5-type catalyst. U.S. Pat. No. 4,181,599 discloses a process for reforming naphtha comprising separating the naphtha into heavy and light fractions and reforming and isomerizing the naphtha fractions. U.S. Pat. No. 4,190,519 teaches a process for upgrading a naphtha-boiling-range hydrocarbon which comprises separating the naphtha feedstock into a light naphtha fraction containing C6 paraffins and lower-boiling hydrocarbons and a heavy naphtha fraction containing higher-boiling hydrocarbons, reforming the heavy naphtha fraction and passing at least a portion of the reformate together with the light naphtha fraction over a zeolite catalyst to produce an aromatics-enriched effluent. Different catalysts may be employed in different process steps during the reforming of naphtha feedstocks as described in U.S. Pat. Nos. 4,627,909, U.S. Pat. No. 4,443,326, U.S. Pat. No. 4,764,267, U.S. Pat. No. 5,073,250, U.S. Pat. No. 5,169,813, U.S. Pat. No. 5,171,691, U.S. Pat. No. 5,182,012, U.S. Pat. No. 5,358,631, U.S. Pat. No. 5,376,259 and U.S. Pat. No. 5,407,558, for example.
Even with the advances in naphtha reforming catalysts and processes, a need still exists to develop new and improved reforming methods to provide higher liquid yield, improve hydrogen production, and minimize the formation of less valuable low molecule weight (C1-C4) products. It has been discovered that interstage feed separation in a staged reforming process and lower pressure in the final stage of a multistage reforming process can improve the RON (Research Octane Number), aromatics content, C5+ liquid yield, hydrogen production, and catalyst life.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that in a multi-stage reforming process, selective reforming of C5-C8 hydrocarbons in a separate or additional reforming stage provides improved performance of the overall reforming process of naphtha feedstocks.
The present invention relates to processes for catalytically reforming a naphtha feed to produce a product reformate in a multistage reforming operation. The process comprises (1) contacting a naphtha boiling range feedstock in a penultimate stage of a multi-stage reforming process at a first reforming pressure with a first reforming catalyst to produce a penultimate effluent; (2) separating at least a portion of the penultimate effluent into at least an intermediate reformate comprising at least 70 vol % C5-C8 hydrocarbons and a heavy reformate comprising at least 70 vol % C9+ hydrocarbons; and (3) contacting the intermediate reformate in a final stage of the multi-stage reforming process at a second reforming pressure with a second reforming catalyst to produce a final effluent comprising a final reformate, wherein the final reformate has a higher RON than the intermediate reformate. Preferably the pressure in the final stage is lower than the pressure in the penultimate stage.
In one embodiment, the reforming catalyst within the penultimate and final stages is the same. In another embodiment, the reforming catalyst within the penultimate stage and final stage are different. In one embodiment the reforming catalyst of the penultimate stage and final stage comprises a Group VIII metal and a promoter supported on a porous refractory inorganic oxide support. In a preferred embodiment, the penultimate stage catalyst is platinum and rhenium on an alumina support. In another embodiment, the final stage catalyst is selected from the group consisting of a Group VIII metal, a molecular sieve, acid catalyst, clays and combinations thereof. In a preferred embodiment the reforming catalyst of the penultimate stage comprises a Group VIII metal and a promoter supported on a porous refractory inorganic oxide support and the reforming catalyst within the final stage comprises zeolite Beta.
In another embodiment, the process of the present invention comprises (1) contacting a naphtha boiling range feedstock in a penultimate stage of a multi-stage reforming process at a first reforming pressure with a first reforming catalyst to produce a penultimate effluent; (2) separating at least a portion of the penultimate effluent into at least a light reformate, an intermediate reformate and a heavy reformate, wherein the light reformate has a mid-boiling point that is lower than that of the intermediate reformate and wherein the light reformate comprises at least 70 vol % C5 hydrocarbons, and wherein the intermediate reformate has a mid-boiling point that is lower than that of the heavy reformate and wherein the intermediate reformate comprises at least 70 vol % C6-C8 hydrocarbons; and (3) contacting the intermediate reformate in a final stage of the multi-stage reforming process at a second reforming pressure with a second reforming catalyst to produce a final effluent comprising a final reformate, wherein the final reformate has a higher RON than the intermediate reformate.
Other aspects, features and advantages will be apparent from the description of the embodiments thereof and from the claims.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0024753.html
Multi-Stage Reforming Process To Produce High Octane Gasoline
United States Patent Application 20120024753
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:
12/845615
Publication Date:
02/02/2012
Assignee:
Chevron U.S.A. Inc.
Abstract:
The present invention relates to a multistage reforming process to produce a high octane product. A naphtha boiling range feedstock is processed in a multi-stage reforming process, in which said process involves at least 1) a penultimate stage for reforming the naphtha feedstock to produce a penultimate effluent 2) a final stage for further reforming at least a portion of the penultimate effluent 3) a regeneration step for the final stage catalyst. The severity of the penultimate stage can be increased during final stage catalyst regeneration in order to maintain the target RON of the reformate product and avoid reactor downtime.
FIELD OF THE INVENTION
The present invention relates to a multistage naphtha reforming process using an interstage separation step to produce a high octane product at high liquid yield and hydrogen production.
BACKGROUND OF THE INVENTION
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 are generally undesirable due to the low value of the resulting light hydrocarbon products.
Catalysts commonly used in commercial reforming reactions often include a Group VIII metal, such as platinum or palladium, or a Group VIII metal plus a second catalytic metal, which acts as a promoter. Examples of metals useful as promoters include rhenium, tin, tungsten, germanium, cobalt, nickel, rhodium, ruthenium, iridium or combinations thereof. The catalytic metal or metals may be dispersed on a support such as alumina, silica, or silica-alumina. Typically, a halogen such as chlorine is incorporated on the support to add acid functionality. In addition to Group VIII metals, other reforming catalysts include aluminosilicate zeolite catalysts. For example, U.S. Pat. Nos. 3,761,389, 3,756,942 and 3,760,024 teach aromatization of a hydrocarbon fraction with a ZSM-5 type zeolite catalyst. U.S. Pat. No. 4,927,525 discloses catalytic reforming processes with beta zeolite catalysts containing a noble metal and an alkali metal. Other reforming catalysts include other molecular sieves such as borosilicates and silicoaluminophosphates, layered crystalline clay-type phyllosilicates, and amorphous clays.
In addition to selection of catalysts for reforming, various processes for reforming a naphtha feedstock in one or more process steps to produce higher value reformate products are known in the art. U.S. Pat. No. 3,415,737 teaches a process for reforming naphtha under conventional mild reforming conditions with a platinum-rhenium-chloride reforming catalyst to increase the aromatics content and octane number of the naphtha. In U.S. Pat. No. 3,770,614 there is disclosed a process in which a reformate is fractionated and the light reformate fraction (C6 fraction) passed over a ZSM-5-type zeolite to increase aromatic content of the product. U.S. Pat. No. 3,950,241 discloses a process for upgrading naphtha by separating it into low- and high-boiling fractions, reforming the low-boiling fraction, combining the high-boiling naphtha with the reformate, and contacting the combined fractions with a ZSM-5-type catalyst. U.S. Pat. No. 4,181,599 discloses a process for reforming naphtha comprising separating the naphtha into heavy and light fractions and reforming and isomerizing the naphtha fractions. U.S. Pat. No. 4,190,519 teaches a process for upgrading a naphtha-boiling-range hydrocarbon which comprises separating the naphtha feedstock into a light naphtha fraction containing C6 paraffins and lower-boiling hydrocarbons and a heavy naphtha fraction containing higher-boiling hydrocarbons, reforming the heavy naphtha fraction and passing at least a portion of the reformate together with the light naphtha fraction over a zeolite catalyst to produce an aromatics-enriched effluent. Different catalysts may be employed in different process steps during the reforming of naphtha feedstocks as described in U.S. Pat. Nos. 4,627,909, U.S. Pat. No. 4,443,326, U.S. Pat. No. 4,764,267, U.S. Pat. No. 5,073,250, U.S. Pat. No. 5,169,813, U.S. Pat. No. 5,171,691, U.S. Pat. No. 5,182,012, U.S. Pat. No. 5,358,631, U.S. Pat. No. 5,376,259 and U.S. Pat. No. 5,407,558, for example.
Even with the advances in naphtha reforming catalysts and processes, a need still exists to develop new and improved reforming methods to provide higher liquid yield, improve hydrogen production, and minimize the formation of less valuable low molecule weight (C1-C4) products. It has been discovered that interstage feed separation in a staged reforming process and lower pressure in the final stage of a multistage reforming process can improve the RON (Research Octane Number), aromatics content, C5+ liquid yield, hydrogen production, and catalyst life.
SUMMARY OF THE INVENTION
The present invention is based on the discovery that in a multi-stage reforming process, selective reforming of C5-C8 hydrocarbons in a separate or additional reforming stage provides improved performance of the overall reforming process of naphtha feedstocks.
The present invention relates to processes for catalytically reforming a naphtha feed to produce a product reformate in a multistage reforming operation. The process comprises (1) contacting a naphtha boiling range feedstock in a penultimate stage of a multi-stage reforming process at a first reforming pressure with a first reforming catalyst to produce a penultimate effluent; (2) separating at least a portion of the penultimate effluent into at least an intermediate reformate comprising at least 70 vol % C5-C8 hydrocarbons and a heavy reformate comprising at least 70 vol % C9+ hydrocarbons; and (3) contacting the intermediate reformate in a final stage of the multi-stage reforming process at a second reforming pressure with a second reforming catalyst to produce a final effluent comprising a final reformate, wherein the final reformate has a higher RON than the intermediate reformate. Preferably the pressure in the final stage is lower than the pressure in the penultimate stage.
In one embodiment, the reforming catalyst within the penultimate and final stages is the same. In another embodiment, the reforming catalyst within the penultimate stage and final stage are different. In one embodiment the reforming catalyst of the penultimate stage and final stage comprises a Group VIII metal and a promoter supported on a porous refractory inorganic oxide support. In a preferred embodiment, the penultimate stage catalyst is platinum and rhenium on an alumina support. In another embodiment, the final stage catalyst is selected from the group consisting of a Group VIII metal, a molecular sieve, acid catalyst, clays and combinations thereof. In a preferred embodiment the reforming catalyst of the penultimate stage comprises a Group VIII metal and a promoter supported on a porous refractory inorganic oxide support and the reforming catalyst within the final stage comprises zeolite Beta.
In another embodiment, the process of the present invention comprises (1) contacting a naphtha boiling range feedstock in a penultimate stage of a multi-stage reforming process at a first reforming pressure with a first reforming catalyst to produce a penultimate effluent; (2) separating at least a portion of the penultimate effluent into at least a light reformate, an intermediate reformate and a heavy reformate, wherein the light reformate has a mid-boiling point that is lower than that of the intermediate reformate and wherein the light reformate comprises at least 70 vol % C5 hydrocarbons, and wherein the intermediate reformate has a mid-boiling point that is lower than that of the heavy reformate and wherein the intermediate reformate comprises at least 70 vol % C6-C8 hydrocarbons; and (3) contacting the intermediate reformate in a final stage of the multi-stage reforming process at a second reforming pressure with a second reforming catalyst to produce a final effluent comprising a final reformate, wherein the final reformate has a higher RON than the intermediate reformate.
Other aspects, features and advantages will be apparent from the description of the embodiments thereof and from the claims.
Free Full Text Source: http://www.freepatentsonline.com/y2012/0024753.html
Implementation results for automated gas-pulsed cleaning systems of TsKTI on petroleum-heating furnaces, heat-recovery boilers, and hot-water boilers
Thermal Engineering , Volume 59, Number 3, 216-220 (2012)
Implementation results for automated gas-pulsed cleaning systems of TsKTI on petroleum-heating furnaces, heat-recovery boilers, and hot-water boilers
A. P. Pogrebnyak, V. L. Kokorev, A. L. Kokorev, I. O. Moiseenko, A. V. Gul’tyaev and N. N. Efimova
Abstract
Describes the long-term positive experience of implementation of gas-pulsed cleaning (GPC) systems of TsKTI, development for heating surfaces of heat-exchange apparatuses for various purposes against external soot-dust, ash, and condensed deposits formed during solid and fluid combustion.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/734262g35438vmm8/
Implementation results for automated gas-pulsed cleaning systems of TsKTI on petroleum-heating furnaces, heat-recovery boilers, and hot-water boilers
A. P. Pogrebnyak, V. L. Kokorev, A. L. Kokorev, I. O. Moiseenko, A. V. Gul’tyaev and N. N. Efimova
Abstract
Describes the long-term positive experience of implementation of gas-pulsed cleaning (GPC) systems of TsKTI, development for heating surfaces of heat-exchange apparatuses for various purposes against external soot-dust, ash, and condensed deposits formed during solid and fluid combustion.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/734262g35438vmm8/
Application of Automatic Temperature Electric Heating Technology in the Fouling Resistance On-Line Monitoring
Proceedings of the 2011 International Conference on Informatics,
Cybernetics, and Computer Engineering (ICCE2011) November 19–20, 2011,
Melbourne, Australia
Advances in Intelligent and Soft Computing, 2012, Volume 112/2012, 779-785
Application of Automatic Temperature Electric Heating Technology in the Fouling Resistance On-Line Monitoring
Mo-Jie Sun, Wen-Jing Yang, Ting Zhang, Chun-Guang Liu and Wei-Dong Wang
Mo-Jie Sun(1)
Wen-Jing Yang(1)
yangwenjing1207@126.com
Ting Zhang(1)
Chun-Guang Liu(1)
Wei-Dong Wang(2)
wangweidong@cpene.com
Author Affiliations
College of Chemical Engineering, Northeast Dianli University, Jilin City, P.R. China
PetroChina Northeast Refining & Chemical Engineering Co.Ltd, Jilin Design Institute, Jilin City, P.R. China
Abstract
In contrast to the traditional method of water heating, automatic temperature electric heating technology to heat the heat exchange tube, with stainless steel pipe monitoring the fouling resistance on-line. Results demonstrate that the monitoring system can accurately reflect the condition of heat exchanger online scaling changes, satisfying the needs of on-line testing.
Automatic temperature electric heating technology does notpose such problems as daily water-replenishing, leakage and equipment overheating. Under the condition of ensuring a safe operation and the long-term stability, it can greatly reduce the amount of daily routine attention, strengthen the assurance factor and lower the cost of production and maintenance.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/770170tt2109412t/
Advances in Intelligent and Soft Computing, 2012, Volume 112/2012, 779-785
Application of Automatic Temperature Electric Heating Technology in the Fouling Resistance On-Line Monitoring
Mo-Jie Sun, Wen-Jing Yang, Ting Zhang, Chun-Guang Liu and Wei-Dong Wang
Mo-Jie Sun(1)
Wen-Jing Yang(1)
yangwenjing1207@126.com
Ting Zhang(1)
Chun-Guang Liu(1)
Wei-Dong Wang(2)
wangweidong@cpene.com
Author Affiliations
College of Chemical Engineering, Northeast Dianli University, Jilin City, P.R. China
PetroChina Northeast Refining & Chemical Engineering Co.Ltd, Jilin Design Institute, Jilin City, P.R. China
Abstract
In contrast to the traditional method of water heating, automatic temperature electric heating technology to heat the heat exchange tube, with stainless steel pipe monitoring the fouling resistance on-line. Results demonstrate that the monitoring system can accurately reflect the condition of heat exchanger online scaling changes, satisfying the needs of on-line testing.
Automatic temperature electric heating technology does notpose such problems as daily water-replenishing, leakage and equipment overheating. Under the condition of ensuring a safe operation and the long-term stability, it can greatly reduce the amount of daily routine attention, strengthen the assurance factor and lower the cost of production and maintenance.
Full Text Source (Subscription or Fee): http://www.springerlink.com/content/770170tt2109412t/
Modeling the thermo-hydraulic performance of direct fired heaters for crude processing
Applied Thermal Engineering, Volume 39, June 2012, Pages
157–162
Modeling the thermo-hydraulic performance of direct fired heaters for crude processing
A. Morales-Fuentesa,
arturo.moralesfn@uanl.edu.mx
G.T. Polleyb,
M. Picón-Núñezb,
S. Martínez-Martíneza
a School of Mechanical and Electrical Engineering, Autonomous University of Nuevo León, México
b Department of Chemical Engineering, University of Guanajuato, México
Abstract
Fouling in heat exchangers for crude processing is a problem which remains unsolved. Fouling models due to coke deposition on the heat transfer surface have been devloped with a high degree of accuracy for single phase situations. Fouling rates in systems where two phase flow takes place, as in fired heaters, need much more study.
Authors adapt a fouling rate model to the case of two phase flow conditions. The model is used to predict the thermo-hydraulic behavior of fired heaters. It predicts how fuel consumption is increased as the thermal resistance builds up on the heat transfer surface.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S1359431112000841
Modeling the thermo-hydraulic performance of direct fired heaters for crude processing
A. Morales-Fuentesa,
arturo.moralesfn@uanl.edu.mx
G.T. Polleyb,
M. Picón-Núñezb,
S. Martínez-Martíneza
a School of Mechanical and Electrical Engineering, Autonomous University of Nuevo León, México
b Department of Chemical Engineering, University of Guanajuato, México
Abstract
Fouling in heat exchangers for crude processing is a problem which remains unsolved. Fouling models due to coke deposition on the heat transfer surface have been devloped with a high degree of accuracy for single phase situations. Fouling rates in systems where two phase flow takes place, as in fired heaters, need much more study.
Authors adapt a fouling rate model to the case of two phase flow conditions. The model is used to predict the thermo-hydraulic behavior of fired heaters. It predicts how fuel consumption is increased as the thermal resistance builds up on the heat transfer surface.
Full Text Source (Subscription or Fee): http://www.sciencedirect.com/science/article/pii/S1359431112000841
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