Hydrocarbon compositions useful for producing fuels and methods of producing the same
A hydrocarbon composition comprises at least 90 wt. % of C 9 to C 20 non-normal olefins, non-normal saturates or combinations thereof based on the weight of the hydrocarbon composition, at least 2 wt. % and not greater than 25 wt. % of C 9 hydrocarbons based on the weight of the hydrocarbon composition, and less than 15 wt. % of C 17 + hydrocarbons based on the weight of the hydrocarbon composition, wherein said hydrocarbon composition has a specific gravity at 15° C. of at least 0.730 and less than 0.775. The composition is produced by oligomerization of at least one C 3 to C 8 olefin and an olefinic recycle stream containing no more than 10 wt. % of C 10 + non-normal olefins. The composition is useful in producing fuel blends, such as jet fuel and diesel fuel.
1. A process for producing a hydrocarbon composition, the process consisting essentially of:
(a) contacting a feed comprising at least one C 3 to C 8 olefin and an olefinic recycle stream with a molecular sieve catalyst in a reactor under olefin oligomerization conditions such that the recycle to feed weight ratio is about 0.5 to about 2.0, the WHSV is at least 1.5 based on the olefin in the feed, and the difference between the highest and lowest temperatures within the reactor is 40° F. (22° C.) or less, said contacting producing a oligomerization effluent stream; and
(b) separating said oligomerization effluent stream into at least a hydrocarbon product stream and said olefinic recycle stream, wherein the olefinic recycle stream contains no more than 10 wt. % of C 10 + non-normal olefins, and the hydrocarbon product stream contains at least 1 wt. % and no more than 30 wt. % of C 9 non-normal olefins.
2. The process of claim 1 wherein said feed comprises a mixture of C 3 to C 5 olefins comprising at least 5 wt. % of C 4 olefin.
3. The process of claim 2 wherein said mixture comprises at least 40 wt. % of C 4 olefin and at least 10 wt. % of C 5 olefin.
4. The process of claim 1 wherein said feed contains C 4 olefin and the contacting (a) is conducted so as to convert about 80 wt. % to about 99 wt. % of the C 4 olefin in the feed.
5. The process of claim 1 wherein the recycle to feed weight ratio in said contacting (a) is about 0.7 to about 1.3.
6. The process of claim 1 wherein the contacting (a) is conducted at a WHSV of about 1.8 to about 9 based on the olefin in the feed.
7. The process of claim 1 wherein the contacting (a) is conducted at a WHSV of about 2.3 to about 14 based on the olefin in the combined feed and olefinic recycle stream.
8. The process of claim 1 wherein the highest and lowest temperatures within the reactor are between about 150° C. and about 350° C.
9. The process of claim 1 wherein said catalyst comprises a molecular sieve having a Constraint Index of about 1 to about 12.
10. The process of claim 1 wherein said catalyst comprises a molecular sieve selected from ZSM-5, ZSM-12, ZSM-22, ZSM-57 and/or MCM-22.
11. The process of claim 1 wherein said olefinic recycle stream contains no more than 7 wt. % of C 10 + non-normal olefins.
12. The process of claim 11 wherein said olefinic recycle stream has a final boiling point of no greater than 340° F. (170° C.).
13. The process of claim 1 wherein said olefinic recycle stream contains no more than 30 wt. % of C 9 + non-normal olefins.
14. The process of claim 13 wherein said olefinic recycle stream has a final boiling point of no greater than 290° F. (140° C.).
15. The process of claim 1 , wherein difference between the highest and lowest temperatures within the reactor is 30° F. (17° C.) or less.