Process development for integrated coal gasification solid oxide fuel cells hybrid power plants – Investigations on solid oxide fuel cells/gas turbine hybrid power plants run on clean coal gas

Abstract

On the road to sustainable generation of electricity, the efficiency of fossil-fuel power plants and CO2 emissions must be increased and decreased respectively. Integrated coal gasification solid oxide fuel cell hybrid power plants have the potential to achieve high power plant efficiencies and enable opportunities for the efficient capture of CO2. The investigation of such power plants is the subject of this publication. The developed systems are based on conventional integrated coal gasification combined cycle technology and integrated with solid oxide fuel cells preceding the combined cycle process. The state of development of the selected solid oxide fuel cell technology is similar to that of integrated coal gasification combined cycles. Along with the base case, several other concepts with and without CO2 capture are developed using various process technologies. Fundamental system and sensitivity analyses are performed using simplified sub-processes to obtain general statements and trends as well as to calculate optimal boundary conditions for the overall systems. The simulations show that the preparation of process gas using a water gas shift reactor before entering the solid oxide fuel cells is beneficial for the overall efficiency. If a CO2 capture process is included, 11–16% lower net efficiencies are achieved. The level of specific CO2 emissions is significantly influenced by the net efficiency of the power plants and the portion of carbon bound as CO2 at the beginning of the CO2 capture process. Here, the combination of CO2 capture and water gas shift reactor upstream of the solid oxide fuel cells is the preferred concept regarding efficiency and CO2 emissions.