Heat integration analysis for an industrial ethylbenzene plant using pinch analysis

In this study, a heat exchanger network (HEN) for an industrial ethylbenzene plant is retrofitted by pinch analysis. In the ethylbenzene process, ethylbenzene is produced by alkylation of ethylene and benzene, and the whole product is used to produce styrene monomer. From the real operating data, a HEN of the ethylbenzene process is extracted. Analysis of the HEN reveals that the current process is operated efficiently, but there is a possibility to improve the heat exchange in light removal columns. After analysis, an alternative HEN is proposed to save the energy. The alternative HEN is achieved by adding a new heat exchanger and changing operating conditions. It reduces the annual energy cost by 5.6%. In order to achieve it, the capital investment is necessary but the annual cost saving will be enough to recover the cost in less than one year.