Reference no: EM131157638

Cunene is made by alkylation of benzene with propylene over zeolite catalyst. To maximize selectivity to desired products, several beds of catalyst are used inside the same reactor. A mixture of feed and recycle benzene enters the top of the reactor and the feed propylene is split so that a portion of the propylene is fed to each catalyst bed. A large excess of benzene is used, to minimize propylene oligomerization and ensure complete reaction of propylene. The reactor product is cooled and sent to a stabilizer column that removes any light hydrocarbons. The bottom from this column is sent to a benzene column that recovers benzene overhead for recycle to the alkylation and trans alkylation reactors. The bottoms from the benzene column are distilled to give commence product and a heavy stream. The heavy stream is further distilled in a heavies column to give a mixture of dipropyl- and tripropyl-benzene overhead and a heavy waste stream as bottoms. The distillate from the heavies column is sent to a trans alkylation reactor and reacted with excess benzene. The product from the trans alkylation reactor is returned to the benzene column. Sketch a block flow diagram of the process.