Processes for converting C4 feeds to isobutylene, polyisobutylene, or derivatives thereof
Embodiments described herein generally relate to new processes for converting C4 feeds to isobutylene. In an embodiment is provided a process for forming isobutylene that includes hydroisomerizing 1,3-butadiene present in a C4 feed to form a hydroisomerization product effluent comprising isobutylene and 2-butene; and forming an isobutylene feed by separating the isobutylene from the hydroisomerization product effluent. Embodiments of the present disclosure also generally relate to new processes for converting C4 feeds to polyisobutylene. In an embodiment is provided a process that includes hydroisomerizing a C4 feed comprising 1,3-butadiene in a hydroisomerization reactor to form a hydroisomerization product effluent comprising isobutylene and 2-butene; separating the isobutylene from the hydroisomerization product effluent to form a first isobutylene-containing feed; forming a reaction mixture comprising a polymerization catalyst and the first isobutylene-containing feed; and reacting the reaction mixture, in a polymerization reactor, to form a polymerization product effluent comprising polyisobutylene.
1. A process for forming isobutylene, the process comprising:
(a) hydroisomerizing, in a hydroisomerization unit, 1,3-butadiene present in a feed to a hydroisomerization product effluent comprising 2-butene, the hydroisomerizing the 1,3-butadiene comprising converting at least a portion of the 1,3-butadiene to the 2-butene;
(b) isomerizing at least a portion of the 2-butene present in the hydroisomerization product effluent to form an isomerization product effluent comprising 1-butene, 2-butene, and isobutylene, the isomerization product effluent having a higher concentration of isobutylene than the concentration of isobutylene in the hydroisomerization product effluent;
(c) combining the isomerization product effluent with the feed to form a mixture; and
(d) hydroisomerizing the mixture in the hydroisomerization unit.
2. The process of claim 1 , wherein:
the mixture formed at (c) comprises 1-butene; and
the hydroisomerizing the mixture at (d) comprises forming 2-butene from the 1-butene present in the mixture.
3. The process of claim 1 , wherein, after (c), the process further comprises:
separating at least a portion of the isobutylene from the mixture.
4. The process of claim 1 , wherein the feed comprising the 1,3-butadiene comprises greater than 3 wt % of the 1,3-butadiene based on a total wt % of the feed.
5. The process of claim 1 , wherein the feed comprising the 1,3-butadiene comprises an effluent from a steam cracker, a catalytic cracker, or combinations thereof.
6. The process of claim 1 , wherein the feed comprising the 1,3-butadiene is free of isobutylene.
7. A process for forming polyisobutylene, the process comprising:
(a) hydroisomerizing, in a hydroisomerization unit, 1,3-butadiene present in a feed to a hydroisomerization product effluent comprising 2-butene, the hydroisomerizing the 1,3-butadiene comprising converting at least a portion of the 1,3-butadiene to the 2-butene;
(b) isomerizing at least a portion of the 2-butene present in the hydroisomerization product effluent to form an isomerization product effluent comprising 1-butene, 2-butene, and isobutylene, the isomerization product effluent having a higher concentration of isobutylene than the concentration of isobutylene in the hydroisomerization product effluent;
(c) combining the isomerization product effluent with the feed to form a mixture;
(d) hydroisomerizing the mixture in the hydroisomerization unit to form a hydroisomerized mixture; and
(e) reacting a reaction mixture comprising at least a portion of the isobutylene present in the hydroisomerized mixture formed at (d) and a polymerization catalyst to form a first polymerization product effluent comprising polyisobutylene (PIB).
8. The process of claim 7 , wherein, after (c), the process further comprises:
separating the isobutylene from the mixture to form a first isobutylene-containing feed.
9. The process of claim 8 , further comprising:
polymerizing isobutylene present in the first isobutylene-containing feed to form a second polymerization product effluent comprising PIB.
10. The process of claim 7 , wherein:
the mixture formed at (c) comprises 1-butene; and
the hydroisomerizing the mixture at (d) comprises forming 2-butene from the 1-butene present in the mixture.
11. The process of claim 7 , further comprising:
removing unreacted isobutylene from the first polymerization product effluent; and
polymerizing the unreacted isobutylene.
12. The process of claim 7 , further comprising:
removing isobutylene oligomer byproducts from the first polymerization product effluent;
cracking the isobutylene oligomer byproducts to form a second isobutylene-containing feed; and
polymerizing isobutylene present in the second isobutylene-containing feed.
13. The process of claim 7 , further comprising:
oligomerizing isobutylene present in the isomerization product effluent to form an oligomerization effluent comprising isobutylene oligomers;
cracking the isobutylene oligomers to form a third isobutylene-containing feed; and
polymerizing isobutylene present in the third isobutylene-containing feed to PIB.
14. The process of claim 13 , wherein, prior to the cracking the isobutylene oligomers to form the third isobutylene-containing feed, the process further comprises:
separating normal butylenes from the oligomerization effluent.
15. The process of claim 7 , wherein the polymerization catalyst comprises a solid polymerization catalyst.
16. The process of claim 15 , further comprising:
separating the solid polymerization catalyst from the first polymerization product effluent;
regenerating polymerization catalyst from the separated solid polymerization catalyst; and
polymerizing isobutylene with the regenerated polymerization catalyst.
17. The process of claim 7 , wherein the feed comprising the 1,3-butadiene comprises greater than 3 wt % of the 1,3-butadiene based on a total wt % of the feed.
18. The process of claim 7 , wherein the feed comprising the 1,3-butadiene comprises an effluent from a steam cracker, a catalytic cracker, or combinations thereof.
19. The process of claim 7 , wherein the feed comprising the 1,3-butadiene is free of isobutylene.