Efficient and low-emission approaches for cost-effective hydrogen, power, and heat production based on chemical looping combustion

Hydrogen production has recently attracted much attention as an energy carrier and sector integrator (i.e., electricity and transport) in future decarbonized smart energy systems. At the same time, power production is highly valued in energy systems as other sectors like transport and heating become electrified. This work compares two different low-emission systems to produce electricity, hydrogen and heat. The proposed systems are based on chemical looping combustion combined with biomass gasification (CLC-BG) and steam methane reforming (CLC-SMR), both benefiting from heat integration between chemical looping combustion and downstream processes. A full process simulation is carried out in Aspen Plus for both systems and detailed modeling is performed for chemical looping combustion. The overall thermal efficiency is calculated to be 71.1% for CLC-BG and 76.4% for CLC-SMR. Co-feeding methane into the biomass gasification process of CLC-BG leads to an enhanced overall efficiency. In comparison to CLC-BG, CLC-SMR exhibits greater potential in terms of power and hydrogen generation, resulting in a higher exergy efficiency of 58.3% as opposed to 44.6%. Assuming market prices of 5.2 USD/GJ for biomass and 9.1 USD/GJ for natural gas, the lowest minimum hydrogen sale price is estimated to be 4 USD/kg for CLC-SMR.