Process of producing cyclohexylbenzene

摘要

In a process for producing cyclohexylbenzene, benzene is contacted with hydrogen under hydroalkylation conditions effective to form a first effluent stream comprising cyclohexylbenzene, cyclohexane, methylcyclopentane, and unreacted benzene. At least a portion of the first effluent stream is contacted with a dehydrogenation catalyst under dehydrogenation conditions to convert at least a portion of the cyclohexane to benzene thereby forming a second effluent stream. The amount of methylcyclopentane in the second effluent stream is different by no more than 65% of the total amount of the portion of the first effluent stream, said amounts being on a weight basis. A methylcyclopentane-containing stream is removed from either the first or the second effluent stream and at least a portion of the second effluent stream containing benzene is recycled to the hydroalkylation step.

主权项

1. A process for producing cyclohexylbenzene, the process comprising:
(a) contacting benzene and hydrogen under hydroalkylation conditions effective to form a first effluent stream comprising cyclohexylbenzene, cyclohexane, methylcyclopentane, and unreacted benzene; (b) separating at least a portion of the first effluent stream into (i) a C6-rich stream comprising benzene and cyclohexane and (ii) a cyclohexylbenzene-rich stream; (c) contacting at least a portion of the C6-rich stream with a dehydrogenation catalyst under dehydrogenation conditions to convert at least 90 wt % of the cyclohexane to benzene thereby forming a second effluent, wherein an amount of methylcyclopentane in the second effluent differs from an amount of methylcyclopentane in the portion of the C6-rich stream by no more than 5 wt %, where the amount of methylcyclopentane in the portion of the C6-rich stream is on the basis of total weight of the portion of the C6-rich stream, and the amount of methylcyclopentane in the second effluent stream is on the basis of the total weight of the second effluent stream; (d) recovering a methylcyclopentane-rich stream from the first effluent stream or the second effluent stream, wherein the methylcyclopentane-rich stream comprises from about 5 wt % to about 50 wt % methylcyclopentane, wherein the wt % is based upon the weight of the methylcyclopentane-rich stream and the recovered methylcyclopentane-rich stream is a motor gasoline blendstock; (e) separating at least a portion of the second effluent stream into a benzene recycle stream; and (f) recycling at least a portion of the benzene recycle stream to the contacting step (a).