Simulation and exergetic evaluation of hydrogen production from sorption enhanced and conventional steam reforming of acetic acid

Abstract

The simulation and exergetic analysis on hydrogen production from conventional steam reforming (SR) and sorption enhanced steam reforming (SESR) of acetic acid, as a major component in the aqueous bio-oil fraction, are presented in this work. The simulation of acetic acid SR and SESR systems were performed in Aspen Plus software where the main chemical reactors used in this work were Gibbs reactors based on Gibbs free energy minimization method. The equilibrium compositions of acetic acid SR and SESR reactors were investigated at different conditions including temperature (200–1000 °C) and steam to carbon molar ratio (S/C, 1–4.5). The increase of temperature and S/C favored hydrogen production in both SR and SESR processes. Higher purity and yield of hydrogen was obtained via SESR reactor than SR reactor. In addition, less CO and no coke were formed in SESR reactor, which showed the advantages of SESR over SR. The exergy efficiencies of acetic acid SR and SESR systems were 61.80% and 66.80%, respectively. The burner and reforming reactor were responsible for major exergy destruction in both SR and SESR systems. At the same time, large exergy destruction was also found in CO2 separation process in SR system. These results and the simplification of hydrogen production system show the better performance of SESR, which can be a promising way for green hydrogen production via aqueous bio-oil fraction.