Process for preparation of ethylbenzene

Claim 1

IN A PROCESS FOR THE PREPARATION OF ETHYLBENZENE BY THE FRIEDEL-CRAFTS REACTION OF LIQUID BENZENE WITH THE ETHYLENE CONTAINED IN A FEED STOCK CONTAINING LESS THAN 60% BY VOLUME ETHYLENE; AND WHEREIN A LIQUID REACTION EFFLUENT IS FORMED, WASHED, NEUTRALIZED AND FRACTIONATED TO SEPARATE (1) A BENZENE RECYCLE STREAM, (2) A PRODUCT ETHYLBENZENE STEAM, AND (3) A POLYETHYLBENZENE RECYCLE STREAM; AND WHEREIN A GASEOUS REACTOR EFFULENT, SATURATED WITH BENZENE AND ALKYLATED BENZENES, IS COOLED AND CHILLED TO CONDENSE OUT PART OF THE BENZENE AND ALKYLATED BENZENES, THE IMPROVEMENT WHICH COMPRISES: RECOVERING RESIDUAL HYDROCARBONS FROM THE CHILLED GASEOUS REACTOR EFFLUENT BY ABSORPTION IN A LEAN LIQUOR IN TWO SEQUENTIAL SCRUBBING STEPS; THE LEAN LIQUOR IN THE FIRST OF SAID STEPS BEING A PORTION OF AT LEAST ONE ETHYLBENZENE RICH PROCESS STEREAM BOILING ABOVE 140*C. AND BELOW 180*C. AT ATMOSPHERIC PRESSURE; AND THE LEAN LIQUOR IN THE SECOND OF SAID STEPS BEING IN PORTION OF AT LEAST ONE POLYETHYLBENZENE RICH STREAM BOILING ABOVE 100*C. AND BELOW 150*C. AT 50 MM. HG.