Process Development for Integrated Coal Gasification SOFC Hybrid Power Plants

Abstract

On the path to sustainable electric power generation the efficiency of fossil-fuel power plants needs to be increased and CO2-emissions have to be reduced respectively. The main goal of the project is therefore to find the most efficient low-carbon power plant configuration, by means of the integration of high temperature fuel cells (SOFC) in integrated coal gasification combined cycle (IGCC), consisting of state-of-the-art power plant components. Various concepts of integrated coal gasification SOFC hybrid power plants have been considered and simulated with Aspen PlusTM software, extended by several user implemented models, like coal gasifier, SOFC and air separation unit. The figure presents the developed base case of hybrid power plant with possible options of CO2-capture. The effectiveness of the straightforward solution, removing CO2 from anode residual gas, is low, caused by limited fuel utilization of the fuel cell. The most effective case is the combination of water-gas-shift-reactor and physical absorption process before SOFC-anode. The reason for this is the high partial pressure of CO2 and the supply of SOFC with hydrogen rich gas. This results in three percentage points higher efficiency than the most investigated IGCC with CO2-capture.