Exergy analysis of ethylbenzene dehydrogenation to styrene monomer

Abstract

In this paper, exergetic analysis for dehydrogenation of ethylbenzene over a potassium-promoted iron oxide catalyst for styrene monomer production is investigated. The purpose of the study is to decrease the work loss in the process. Due to the high energy consumption of the unit, exergy analysis was used to optimize the energy consumption of styrene production unit and associated fractionation unit. Preheater, second reactor, and benzene–toluene tower were studied to optimize energy consumption. It is observed that coupling of an Liquified Natural Gas (LNG) type of heat exchanger with preheater improves the exergetic efficiency of the preheater. Also, decreasing the pressure of benzene–toluene column from 220 kPa to 60 kPa increases the exergetic efficiency from 77.45 to 90.86, while by optimizing the oxygen injection rate to the second reactor, the exergetic efficiency increased from 25.76 to 38.07.