Catalyst and method for fuels hydrocracking (Exxonmobil Research And Engineering Company)

CATEGORY: HYDROCRACKING
PATENT
Catalyst and method for fuels hydrocracking (Exxonmobil Research And Engineering Company)
Publication number
US20120318712 A1
Application number
13/493,259
Publication date
Dec 20, 2012
Filing date
Jun 11, 2012
Inventors
David L. Vannauker
Richard A. Demmin
Original Assignee
Exxonmobil Research And Engineering Company
Abstract
Fuels hydrocracking can be used to generate a variety of product slates. Varying the temperature can allow an amount of naphtha product and an amount of unconverted product to be varied. The method can be enabled by a hydrocracking catalyst that includes a combination of metals with activity for hydrodesulfurization.
FIELD OF THE INVENTION
Catalytic methods are described below for fuels hydrocracking to make multiple fuel products.
BACKGROUND OF THE INVENTION
One method for increasing the feedstocks suitable for production of fuels can be to use cracking to convert higher boiling petroleum feeds to lower boiling products. For example, distillate boiling range feeds can be hydrocracked to generate additional naphtha boiling range products. Historically, many fuels hydrocracker reaction systems were operated to generate a maximum amount of naphtha for motor gasoline.
SUMMARY OF THE INVENTION
In one embodiment herein is a method for producing a naphtha product and an unconverted product, comprising:
exposing a first feedstock to a first hydrocracking catalyst in a first reaction vessel under first hydrocracking conditions to form a first hydrocracked effluent including at least a first liquid phase portion, at least about 60 wt % of the first feedstock boiling above about 400° F. (about 204° C.) and at least about 60 wt % of the first feedstock boiling below about 650° F. (about 343° C.), the first hydrocracking catalyst comprising Ni, Mo, and W on an acidic support, the ratio of Mo to W being from about 2:1 to about 1:2;
fractionating the first liquid phase portion and at least a portion of a second liquid phase portion to form a first naphtha fraction and a first unconverted fraction, the first naphtha fraction corresponding to at least about 80 wt % of the first feedstock and having a final boiling point of about 400° F. (about 204° C.) or less;
withdrawing a portion of the first unconverted fraction as a first unconverted product, a weight of the withdrawn first unconverted product corresponding to from about 5 wt % to about 15 wt % of the first feedstock, the withdrawn first unconverted product having an initial boiling point of at least about 400° F. (about 204° C.);
separating at least a portion of the remaining portion of the first unconverted fraction as a second feedstock;
exposing the second feedstock to a second hydrocracking catalyst in a second reactor vessel under second hydrocracking conditions to form a second hydrocracked effluent including at least the second liquid phase portion; and
separating the second hydrocracked effluent to produce the second liquid phase portion;
wherein the temperature of the second hydrocracking conditions is at least about 20° F. (11° C.) less than the temperature of the first hydrocracking conditions, and wherein the temperature of the first hydrocracking conditions at start-of-run is less than about 710° F. (377° C.).
In another embodiment herein is a method for producing a naphtha product and an unconverted product, comprising:
exposing a first feedstock to a first catalyst in a first reaction vessel under hydrotreating conditions to form a first reactor effluent;
exposing at least a portion of the first reactor effluent to a first hydrocracking catalyst in a second reaction vessel under first hydrocracking conditions to form a first hydrocracked effluent;
including at least a first liquid phase portion, at least about 60 wt % of the first feedstock boiling above about 400° F. (about 204° C.) and at least about 60 wt % of the first feedstock boiling below about 650° F. (about 343° C.), and the first hydrocracking catalyst comprising Ni, Mo and W on an acidic support, the ratio of Mo to W being from about 2:1 to about 1:2;
fractionating the first liquid phase portion d at least a portion of a second liquid phase portion to form a first naphtha fraction and a first unconverted fraction, the first naphtha fraction corresponding to at least about 80 wt % of the first feedstock and having a final boiling point of about 400° F. (about 204° C.) or less;
withdrawing a portion of the first unconverted fraction as a first unconverted product, a weight of the withdrawn first unconverted product corresponding to from about 5 wt % to about 15 wt % of the first feedstock, the withdrawn first unconverted product having an initial boiling point of at least about 400° F. (about 204° C.);
separating at least a portion of the remaining portion of the first unconverted fraction as a second feedstock;
exposing the second feedstock to a second hydrocracking catalyst in a third reaction vessel under second hydrocracking conditions to form a second hydrocracked effluent including at least the second liquid phase portion; and
separating the second hydrocracked effluent to produce the second liquid phase portion;
wherein the temperature of the second hydrocracking conditions is at least about 20° F. (11° C.) less than the temperature of the first hydrocracking conditions, and wherein the temperature of the first hydrocracking conditions at start-of-run is less than about 710° F. (377° C.).
Free Full Text Source: http://www.google.com/patents/US20120318712?dq=inassignee:exxonmobil&hl=en&sa=X&ei=M8eTUYmxCKmB0QGu2YDoCQ&ved=0CDwQ6AEwATgU