Method for increasing light olefin yield by conversion of a heavy hydrocarbon fraction of a product to light olefins
AssigneeExxonMobil Chemical Patents Inc.
InventorStephen Neil Vaughn
Life of this patent
Estimating the term…
Abstract
A method for increasing light olefin yield during conversion of oxygenates to olefins comprising: contacting an oxygenate feed in a primary reactor with a non-zeolitic molecular sieve catalyst under conditions effective to produce a first product comprising light olefins; separating the first product into light olefins and a heavy hydrocarbon fraction; feeding the heavy hydrocarbon fraction either back into the primary reactor or to a separate auxiliary reactor; and, subjecting the heavy hydrocarbon fraction to conditions effective to convert at least a portion of the heavy hydrocarbons to light olefins.
Claims22
A method for increasing light olefin yield during conversion of oxygenates to olefins comprising:
- (a) contacting an oxygenate feed in a primary reactor with a non-zeolitic molecular sieve catalyst under first conditions effective to produce a first product comprising light olefins;
- (b) separating said first product into said light olefins and a heavy hydrocarbon fraction comprising heavy hydrocarbons;
- (c) feeding said heavy hydrocarbon fraction to a second reactor selected from the group consisting of said primary reactor and a separate auxiliary reactor;
- and
- (d) subjecting said heavy hydrocarbon fraction in said second reactor to second conditions effective to convert at least a portion of said heavy hydrocarbons to light olefins.
A method for increasing light olefin yield during conversion of oxygenates to olefins comprising:
- (a) contacting an oxygenate feed in a primary reactor with a first, non-zeolitic molecular sieve catalyst under first conditions effective to produce a first product comprising light olefins;
- (b) separating said first product into said light olefins and a heavy hydrocarbon fraction comprising heavy hydrocarbons;
- (c) feeding said heavy hydrocarbon fraction to a separate auxiliary reactor;
- and
- (d) contacting said heavy hydrocarbon fraction with a second molecular sieve catalyst in said separate auxiliary reactor under conditions effective to promote conversion of said heavy hydrocarbons to light olefins.
A method for increasing light olefin yield during conversion of oxygenates to olefins comprising:
- (a) contacting an oxygenate feed in a primary reactor with a silicoaluminophosphate selected from the group consisting of SAPO-44, SAPO-34, SAPO-18, and SAPO-17, under first conditions effective to produce a first product comprising light olefins;
- (b) separating said first product into said light olefins and a heavy hydrocarbon fraction comprising heavy hydrocarbons;
- (c) feeding said heavy hydrocarbon fraction to a separate auxiliary reactor;
- and
- (d) contacting said heavy hydrocarbon fraction with ZSM-5 in said separate auxiliary reactor under conditions effective to promote conversion of said heavy hydrocarbons to light olefins.
A method for increasing light olefin yield during conversion of oxygenates to olefins comprising:
- (a) contacting an oxygenate feed in a primary reactor with a non-zeolitic molecular sieve catalyst under conditions effective to produce a product comprising light olefins;
- (b) separating said product into said light olefins and a heavy hydrocarbon fraction comprising heavy hydrocarbons;
- and
- (c) recycling said heavy hydrocarbon fraction to said primary reactor.
Dependencies are inferred from the claim text.