Carbon-negative Hydrogen: Exploring the Techno-economic Potential of Biomass Co-gasification with CO2 Capture

The hydrogen economy is receiving increasing attention as a complement to electrification in the global energy transition. Clean hydrogen production is often viewed as a competition between natural gas reforming with CO2 capture and electrolysis using renewable electricity. However, solid fuel gasification with CO2 capture presents another viable alternative, especially when considering the potential of biomass to achieve negative CO2 emissions. This study investigates the techno-economic potential of hydrogen production from large-scale coal/ biomass co-gasification plants with CO2 capture. With a CO2 price of 50 €/ton, the benchmark plant using commercially available technologies achieved an attractive hydrogen production cost of 1.78 €/kg, with higher CO2 prices leading to considerable cost reductions. Advanced configurations employing hot gas clean-up, membrane-assisted water-gas shift, and more efficient gasification with slurry vaporization and a chemical quench reduced the hydrogen production cost to 1.50–1.62 €/kg with up to 100% CO2 capture. Without contingencies added to the pre-commercial technologies, the lowest cost reduces to 1.43 €/kg. It was also possible to recover waste heat in the form of hot water at 120 ◦C for district heating, potentially unlocking further cost reductions to 1.24 €/kg. In conclusion, gasification of locally available solid fuels should be seriously considered next to natural gas and electrolysis for supplying the emerging hydrogen economy.