Comparison of Coal Based Hydrogen and Electricity Co-Generation Processes under a Carbon Constrained Scenario

Hydrogen and electricity produced from coal will represent a significant share in the energy mix within the foreseeable future. Various novel processes are developed or currently under development for hydrogen and electricity production from coal derived syngas. The commercial coal to hydrogen and coal to electricity processes include the coal gasification-water gas shift process and integrated gasification combined cycle (IGCC) process. More advanced approaches include enhanced water-gas-shift membrane technology and chemical looping technology. This paper compares these technologies on the same baseline via Aspen Plus simulation with common assumptions. Firstly, performance of the key reactors, e.g. the reducer/oxidizer of the chemical looping system and the hydrogen-/carbon dioxideselective water-gas-shift membrane reactor of the membrane system, are investigated and modeled based on thermodynamic principles. Operating conditions such as feed rate, operating temperature and pressure are then optimized. The optimized reactor models are integrated into a common coal gasification system to obtain the overall performance and energy conversion efficiencies of different process configurations. The results are helpful in opting and optimizing the design of future coal to hydrogen/electricity processes. 1 To whom the correspondence should be addressed