화학공학소재연구정보센터
Energy & Fuels, Vol.21, No.4, 2272-2277, 2007
Hydrogen and electricity from coal with carbon dioxide separation using chemical looping reactors
Concern about global climate change has led to research on low CO2 emission in the process of the energy conversion of fossil fuel. One of the solutions is the conversion of fossil fuel into carbon-free energy carriers, hydrogen, and electricity with CO2 capture and storage. In this paper, the main purpose is to investigate the thermodynamics performance of converting coal to a hydrogen and electricity system with chemical-looping reactors and to explore the influences of operating parameters on the system performance. Using FeO/Fe3O4 as an oxygen carrier, we propose a carbon-free coproduction system of hydrogen and electricity with chemical-looping reactors. The performance of the new system is simulated using ASPEN PLUS software tool. The influences of the chemical-looping reactor's temperature, steam conversion rate, and O-2/coal quality ratio on the system performance, and the exergy performance are discussed. The results show that a high-purity of H-2 (99.9%) is reached and that CO2 can be separated. The system efficiency is 57.85% assuming steam reactor at 815 degrees C and the steam conversion rate 37%. The system efficiency is affected by the steam conversion rate, rising form 53.17 to 58.33% with the increase of the steam conversion rate from 28 to 41%. The exergy efficiency is 54.25% and the losses are mainly in the process of gasification and HRSG.