Development of a Novel Exergy Tool for Realizing an Energy Efficient Naphtha Reforming Process

Abstract

In order to realize an energy-efficient naphtha reforming process, various energy analysis methods are adopted. These methods are based on the first law of thermodynamics or a combination of the first and second law of thermodynamics. The conventional method of energy analysis based on the first law of thermodynamics is inadequate because it cannot grasp the effect of system irreversibilities. Exergy analysis which embeds second law of thermodynamics in the conventional method overcomes this deficiency and represents the true thermodynamic efficiency of the process. In this work, a novel technique based on computational fluid dynamics is proposed to perform exergy analysis of naphtha reforming reactors. N-heptane cut of naphtha reforming process which comprises of paraffin, aromatics and naphthene are used to conduct this analysis. Three reactors, connected in series, are used and all the three types of exergy, i.e., physical exergy, chemical exergy and mixing exergy, are examined. It is analyzed that the physical and mixing exergy in the reactors is decreasing along the length of the reactors whereas the chemical energy increases due to the high chemical potential of products.