Performance of an Integrated Adsorption-Enhanced Glycerol Supercritical Water Reforming and Pressurized SOFC System

Abstract

Glycerol supercritical water reforming is a promising process for hydrogen production. The hydrogen product has high pressure and temperature and thus, it can be used as fuel in pressurized solid oxide fuel cells (SOFC). However, the synthesis gas obtained from reforming process contains high amount of CO 2 and this leads to the deterioration of SOFC performance. Consequently, the adsorption process is used to remove CO 2 from the synthesis gas before feeding into SOFCs. This work aimed to develop models of an integrated system of adsorption-enhanced glycerol supercritical water reforming process and pressurized SOFC. The AspenPlus TM simulation software was used to calculate the equilibrium compositions of the products from reforming process by the minimization of Gibbs free energy method. The SOFC performance can be computed by electrochemical equations taking into account three voltage losses (activation, ohmic and concentration losses). Effect of operating conditions of SOFC (temperature, pressure and current density) was examined to identify the optimal operating condition. The simulation results indicated that the optimal conditions for SOFC are temperature of 900 °C, pressure of 4 atm and current density of 10,000 A/m 2. The glycerol reformer which is operated at temperature of 800 o C, pressure of 240 atm and steam to glycerol molar ratio of 10 can provide the hydrogen product of 87% (dry basis). When the synthesis gas is fed into SOFC operated under the optimal condition, it was found that the integrated system can be achieved the SOFC efficiency of 71.56%.