CPC C07C 7/177 (2013.01) [B01D 3/009 (2013.01); B01D 3/141 (2013.01); B01D 3/143 (2013.01); B01J 8/0419 (2013.01); C07C 2/08 (2013.01); C07C 2/16 (2013.01); C07C 5/03 (2013.01); C07C 2527/03 (2013.01)] | 9 Claims |
1. A process for the dimerization of isoolefins, the process comprising:
feeding an oxygenate reaction modifier and a hydrocarbon feed to a fixed bed reactor containing an oligomerization catalyst, the hydrocarbon feed comprising isobutene and a secondary feed comprising butanes;
reacting isobutene in the fixed bed reactor at oligomerization conditions to form a reaction effluent comprising the oxygenate reaction modifier, isobutene dimers, unreacted isobutene, any oxygenate reaction byproducts formed, as well as butanes;
without componential separation, feeding the reaction effluent to a second fixed bed reactor containing an oligomerization catalyst;
reacting the unreacted isobutene in the second fixed bed reactor at oligomerization conditions to form additional isobutene dimers, recovering a second reaction effluent comprising the oxygenate reaction modifier, isobutene dimers, any oxygenate reaction byproducts formed, as well as butanes;
without componential separation, feeding the second reaction effluent to a catalytic distillation reactor having a reactive distillation zone comprising an oligomerization catalyst;
concurrently within the catalytic distillation reactor:
reacting unreacted isobutene in the second reaction effluent to form additional isobutene dimers;
separating the dimers and the oxygenate reaction byproducts, recovered as a bottoms fraction, from the isobutane and n-butane, and any unreacted isobutene, recovered as an overheads fraction; and
recycling the overheads fraction to the hydrocarbon feed;
wherein the bottoms fraction further comprises the oxygenate reaction modifier and isobutene trimers, the process further comprising separating the bottoms fraction in a divided wall distillation column to recover an overheads fraction, a side draw fraction comprising the isobutene dimers, and a bottoms fraction comprising the isobutene trimers; and
wherein the side draw fraction comprises greater than 95 wt % isobutene dimers.
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