CPFD simulation study on oxygen-enriched gasification characteristics of biomass in circulating fluidized bed gasifier

• It was found that the optimal oxygen concentration threshold was 41%. • The temperature variation of the bed layer is dominated by the combustion reaction. • The gasification process shows obvious spatial zoning characteristics. • With the increase of O 2 concentration, the LHV of the gas increases, but the effective rate inflection point. Biomass has the natural advantage of zero carbon emissions, and the use of its gasification in different industrial sectors has become a new trend. However, biomass gasification syngas is unstable due to the influence of raw materials and operating conditions, and the mechanism for adjusting gasification characteristics as needed is not clear. This study comprehensively analyzed the oxygen enriched gasification characteristics of industrial CFB gasifier using computational particle fluid dynamics (CPFD) method, including gas–solid flow, bed temperature distribution, gas concentration distribution, and gasification characteristics. The study shows that pure oxygen replaces air and maintains a constant oxygen supply, CFB gasifiers exhibit optimal thermochemical performance at an oxygen concentration of 41 %. Assuming that the pyrolysis process occurs uniformly within the particles, the carbon conversion rate and gasification efficiency of gasification products decreased by 3 % and 1 %. The proportion of H 2 and C O increased by 8 % and 5 %, and the calorific value increased by 60 %. This study enhances the understanding of oxygen enriched gasification process, and it provides theoretical support for optimizing gasification characteristic regulation.