Thermodynamic investigation of biomass-steam gasification in converter vaporisation flue for synthesis gas production

Abstract

Biomass gasification for hydrogen production is a highly promising technology for energy conversion and utilisation. This paper proposed a novel technology for the injection of biomass and steam into the flue of a converter vaporisation to produce hydrogen-rich syngas. The feasibility of hydrogen generation through gasification between biomass, steam, and carbon dioxide in the high-temperature flue gas was investigated based on the thermodynamic principle of Gibbs free energy minimisation. The influence of gasification parameters on the composition of syngas was also explored. The results indicate that in the gasification process, biomass and steam injected into the converter vaporisation flue can effectively inhibit the generation of by-products such as tar. As the steam volume increases, the volume fraction of hydrogen in the product also increases, while the concentration of carbon monoxide decreases. By adjusting the steam-to-biomass ratio, syngas with a hydrogen content exceeding 20% can be produced. At a reaction temperature of 1200 °C, with a steam addition of 5%, a biomass addition of 8 g/L, and a $V_{CO}/V_{C{O}_2}$ ratio of 3, the gas products are composed of 25% hydrogen and 67% carbon dioxide. The process has the potential to achieve a hydrogen yield of up to 90%, a syngas yield of 94%, and a CO₂ conversion rate of 70%. Additionally, the lower heating value of the syngas is measured at 11.24 MJ/Nm³. The research results have confirmed the viability of the new technology, thus establishing a theoretical foundation for the industrial implementation of injecting biomass and steam into the converter vaporisation flue to produce hydrogen-rich syngas.