Patent ID: 11939289
Assignee: LUMMUS TECHNOLOGY LLC
Field: Chemical engineering (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 4:
5. 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 consisting of isoolefins and n-paraffins;
reacting isoolefins in the fixed bed reactor at oligomerization conditions to form a reaction effluent comprising the oxygenate reaction modifier, isoolefin dimers, unreacted isoolefin, any oxygenate reaction byproducts formed, as well as n-paraffins;
without componential separation, feeding the reaction effluent to a second fixed bed reactor containing an oligomerization catalyst;
reacting the unreacted isoolefins in the second fixed bed reactor at oligomerization conditions to form additional isoolefin dimers, recovering a second reaction effluent comprising the oxygenate reaction modifier, isoolefin dimers, any oxygenate reaction byproducts formed, as well as n-paraffins;
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 isoolefins in the second reaction effluent to form additional isoolefin dimers;
separating the dimers and the oxygenate reaction byproducts, recovered as a bottoms fraction, from the n-paraffin, and any unreacted isoolefin, recovered as an overheads fraction;

recycling the overheads fraction to the hydrocarbon feed;
wherein the bottoms fraction further comprises the oxygenate reaction modifier and isoolefin 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 isoolefin dimers, and a bottoms fraction comprising the isoolefin trimers; and
wherein the side draw fraction comprises greater than 95 wt % isoolefin dimers.