Mini Review of Catalytic Reactive Flash Volatilization of Biomass for Hydrogen-Rich Syngas Production

While the global energy demand is estimated to increase, the energy supply has to transition from fossil fuels to renewable energy to reduce CO2 emissions to avoid the consequences of climate change. Hydrogen produced from renewable resources can play a vital role as a sustainable energy carrier. Among several routes of H2 production, thermochemical conversion of biomass into hydrogen has been gaining much interest. Catalytic steam gasification via reactive flash volatilization (RFV) technology is a proven method for producing tar-free hydrogen-rich syngas from a range of biomass at relatively low temperatures (<900 °C) in a single-step millisecond residence time reactor. Here, we review the recent literature and evaluate the economic prospects of catalytic RFV gasification of different biomass. The performance of RFV has been compared to other types of gasification technologies based on the data available in the published literature. Parameters affecting RFV performance include the temperature, steam and oxygen supply, catalyst, and biomass type. A higher temperature and steam/carbon ratio was favorable for the hydrogen yield, whereas the optimal carbon/oxygen ratio was required to achieve a high quality and yield of syngas. Ni-based catalysts were found to be excellent for steam reforming of tar, C2 compounds and methane; and water gas shift reactions, regardless of the biomass used. Techno-economic factors affecting the cost of hydrogen were process efficiency, cost of biomass, scale of the plant, carbon tax, capital cost, and location-specific factors, such as cost of labor and utility.