Exergetic evaluation and optimisation of primary methane steam reformer

Abstract

It is widely accepted that exergy diagnosis on reactor often overlooks the intrinsic reaction and physico-chemical factors in the reactor itself. In this work, these factors are included to analyse their influence on the exergetic performances of the primary steam reformer (PMSR). Thermal and steam to carbon (S/C) ratio sensitivity assessment was performed to obtain the optimal operating conditions of the reactor. Aside of the conventional exergetic analysis, physical-chemical exergy destruction ratio was also introduced to determine the most dominant irreversibility in the system. Results of numerical simulation showed that higher temperature increases hydrogen production and at the same S/C ratio, decreases chemically-driven exergy destruction. The exception applied on very low S/C (around 2) and very high temperature (880°C-900°C), where significant physico-thermally-driven exergy destruction was observed. On the other hand, excessive steam leads to more exergy losses, while the exergy destruction was kept at minimal and more chemically-driven.