Gas Separation and Recycling using Inorganic Membranes in a Molten Carbonate Fuel Cell System

摘要

Molten carbonate fuel cell (MCFC) is an electrochemica reactor that converts chemical energy of fuel directly into electrical energy at high temperature around 650 deg C. Gas recycling is necessary in a large-scale MCFC system to cool the stack and to enhance energy conversion efficiency. In this study, we investigated the anode gas recyling system of MCFC in combination with hydrogen separation using inorganic membranes. The gas separation characteristics of inorganic membranes formed by a variety of method were evaluated at 600 deg C using a gas mixture obtained fro mthe real MCFC stack. Then performance of a MCFC system with an inorganic membrane separator was estimated using a simple model. Since hydrogen permeates through the membranes faster than other gase, the anode gas recycling combiend with hydrogen separator increases the hydrogen concentration at the anode chamber, leading to the higher cell performanc.e Effect of the gas recycling ratio on the cell performance was investigated. In order for these membranes to be used in practice, however, it is necessary to enhance the hydrogen permselectivity of the membranes.