Benzene → Cyclohexylbenzene

Participants

Reaction Steps

FIG. 2 is a diagram of a reactive distillation unit for conducting the dealkylation step of the process shown in FIG. 1. The embodiment shown in FIG. 2 includes a vertical distillation tower 111 which is provided with a cracking zone 112 located near the base of the tower, which also receives the optional benzene and hydrogen feeds. The product of the hydroalkylation reactor, after removal of the unreacted benzene, is introduced by line 113 into the tower mid-way along the tower 111. On entering the distillation tower 111, the hydroalkylation product is separated into a C18 fraction, which descends through the tower to the cracking zone 112, and a C12 fraction which leaves the tower as overhead 114. The C18 fraction is dealkylated in the cracking zone to produce monocyclohexylbenzene product cyclohexene, and/or cyclohexane, which exit the tower 111 as part of the overhead 114. The overhead is then passed through a cooler 115 to remove any unreacted PCHB, which is recycled to the tower via line 116 and any unreacted hydrogen, which is vented from the cooler via line 117. The remaining overhead, which is composed mainly of cyclohexylbenzene, cyclohexene, and/or cyclohexane, is then passed to a distillation system (not shown) to separate the C6 and C12 fractions. Any unreacted C18 and heavier compounds (i.e., heavies) exit through the bottoms stream of the column.

Provenance & Evidence