Process for the co-production of cumene and secondary butyl benzene
View Patent ↗Cumene and secondary butyl benzene are produced simultaneously in a distillation column reactor by feeding propylene, butylene and benzene to the reactor. Unreacted benzene is removed as overheads and cumene and secondary butyl benzene are removed as products. The catalysts used are acid cation exchange resins, zeolites, particularly beta zeolite.
1. A process for the concurrent production of cumene and secondary butyl benzene comprising the steps of:
(a) feeding a first stream consisting essentially of benzene and a second stream consisting essentially of propylene and butylene to a distillation column reactor containing a bed of alkylation catalyst;
(b) concurrently in said distillation column reactor;
(i) reacting a portion of said benzene with a portion of said propylene and said butylene to form a reaction mixture containing unreacted benzene, unreacted propylene, unreacted butylene, cumene and secondary butyl benzene;
(ii) separating the unreacted benzene, unreacted propylene and unreacted butylene from the cumene and secondary butyl benzene by fractional distillation;
(c) removing the unreacted benzene, unreacted propylene and unreacted butylene from said distillation column reactor as overheads; and
(d) removing the cumene and secondary butyl benzene from said distillation column reactor as bottoms.
2. The process according to claim 1 wherein there is a molar excess of benzene to propylene and butylene.
3. The process according to claim 1 wherein said overheads are fed to a finishing reactor containing a bed of alkylation catalyst to react any remaining propylene and butylene with benzene to form additional cumene and secondary butyl benzene.
4. The process according to claim 3 wherein the effluent from said finishing reactor is returned to said distillation column reactor as reflux.
5. The process according to claim 1 wherein dialkyl benzenes are formed and are removed as bottoms along with said cumene and said secondary butyl benzene and further comprising the steps of:
(e) feeding said bottoms to a distillation column where said cumene and said secondary butyl benzene are removed as overheads and said dialkyl benzenes are removed as a second bottoms; and
(f) feeding said second bottoms containing said dialkyl benzenes and benzene to a transalkylation reactor containing a transalkylation catalyst where a portion of said dialkyl benzene is converted to mono alkyl benzene.
6. The process according to claim 1 wherein said alkylation catalysts are selected from the group consisting of acid cation exchange resins and zeolites.
7. The process according to claim 6 wherein said alkylation catalysts comprise beta zeolite.