Thermodynamic study on the integrated supercritical water gasification with reforming process for hydrogen production: Effects of operating parameters

In this paper, a conceptual process design of the integrated supercritical water gasification (SCWG) and reforming process for enhancing H-2 production has been developed. The influence of several operating parameters including SCWG temperature, SCWG pressure, reforming temperature, reforming pressure and feed concentration on the syngas composition and process efficiency was investigated. In addition, the thermodynamic equilibrium calculations have been carried out based on Gibbs free energy minimization by using Aspen Plus. The results showed that the higher H-2 production could be obtained at higher SCWG temperature, the H-2 concentration increased from 5.40% at 400 degrees C to 38.95% at 600 degrees C. The lower feed concentration was found to be favorable for achieving hydrogen-rich gas. However, pressure of SCWG had insignificant effect on the syngas composition. The addition of reformer to the SCWG system enhanced H-2 yield by converting high methane content in the syngas into H-2. The modified SCWG enhanced the productivity of syngas to 151.12 kg/100kg(feed) compared to 120.61 kg/100kg(feed )Of the conventional SCWG system. Furthermore, H-2 yield and system efficiency increased significantly from 1.81 kg/100k(feed) and 9.18% to 8.91 kg/100kg(feed), and 45.09%, respectively, after the modification. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.