Simulation of the deoxygenated and decarburized biomass cascade utilization system for comprehensive upgrading of green hydrogen generation

Abstract

Steam gasification of biomass is of great significance for achieving efficient hydrogen-rich syngas production. However, the yield and the quality of H2 in the product require further improvements. In this study, a strengthened biomass cascade utilization system via synergistic deoxygenation and decarburization is investigated. The system is composed of a deoxygenated and decarburized gasification reactor and a deoxidizer and decarburizer material regenerator. In the gasification reactor, a series of deoxidizer and decarburizer materials, CaO-Fe (Ca: Fe > 1.0), are applied for accomplishing high-quality hydrogen production; In the regenerator, the deoxidizer and decarburizer material is regenerated (CaCO3+ Ca2Fe2O5→CaO–Fe) with released gas utilization. The effects of gasification temperatures, Ca/Fe, H2O/C, and (CaO + Fe)/B mole ratios are evaluated by Aspen Plus, achieving comprehensive optimization of the parameters. The H2 yield reaches 68.16 mol s−1 kg−1 biomass and the H2 concentration is up to 93.58 vol%, which increases by 254.45 % and 109.87 % compared with the results without deoxygenation and decarburization. Additionally, the deoxidizer and decarburizer material can be completely regenerated via released gas reduction, thereby ensuring the consistent looping of the entire system. This paper sheds light on the synergistic deoxygenation and decarburization methodology for biomass-to-hydrogen generation, which provides a robust guidance for further experiments in the future.