Coal based hydrogen production process with CO₂ recovery

Hydrogen is recognized as an environmentally clean energy source for electricity generation, alternative fuel and other applications since it is zero emission. Coal is one important source for hydrogen production, which has special value for China because it’s rich in coal but limited in natural gas and oil. More important, coal can be utilized in low carbon way through integrating CO₂ capture into hydrogenation production process. However, with the current technology, the energy efficiency of producing hydrogen from coal is around 60%, which limits the full chain efficiency of coal utilization. It is therefore extremely important to develop more efficient methods of H₂ production from coal. In this paper, a new type of hydrogen production process with a three-step coal gasification is introduced. The Aspen Plus Software is selected to simulate the system. Then the Exergy-Utilization Diagram (EUD) analyses are applied to disclose the mechanism of key processes. The result reveals that the efficiency of hydrogen production can be upgraded to 67% due to removing air separation unit and CO₂ separation process. Thereby the hydrogen production process introduced in this paper has a good thermodynamic performance and may provide a quite promising way for high efficient and clean coal utilization.