The effect of gasification reactions on biomass char conversion under pulverized fuel combustion conditions was studied by single particle experiments and modelling. Experiments of pine and beech wood char conversion were carried out in a single particle combustor under conditions of 1473-1723 K, 0.0-10.5% O₂, and 25-42% H₂O. A comprehensive progressive char conversion model, including heterogeneous reactions (char oxidation and char gasification with CO₂ and H₂O), homogeneous reactions (CO oxidation, water-gas shift reaction, and H₂ oxidation) in the particle boundary layer, particle shrinkage, and external and internal heat and mass transfer, was developed. The modelling results are in good agreement with both experimental char conversion time and particle size evolution in the presence of oxygen, while larger deviations are found for the gasification experiments. The modelling results show that the char oxidation is limited by mass transfer, while the char gasification is controlled by both mass transfer and gasification kinetics at the investigated conditions. A sensitivity analysis shows that the CO oxidation in the boundary layer and the gasification kinetics influence significantly the char conversion time, while the water-gas shift reaction and H₂ oxidation have only a small effect. Analysis of the sensitive parameters on the char conversion process under a typical pulverized biomass combustion condition (4% O₂, 13% CO₂, 13% H₂O), shows that the char gasification reactions contribute significantly to char conversion, especially for millimeter-sized biomass char particles at high temperatures.

通过单颗粒实验和建模研究了气化反应对粉状燃料燃烧条件下生物质焦转化的影响。在1473-1723 K，0.0-10.5％O ₂和25-42％H ₂ O的条件下，在单个颗粒燃烧器中进行了松木和山毛榉木炭转化实验。（焦炭氧化和用CO ₂和H ₂ O进行焦炭气化），均相反应（CO氧化，水煤气变换反应和H ₂颗粒边界层中的氧化），颗粒收缩以及内部和外部的传热和传质都得到了发展。建模结果与在氧气存在下的实验焦炭转化时间和粒度演变都非常吻合，而对于气化实验则发现较大的偏差。模拟结果表明，在研究条件下，炭的氧化受传质的限制，而炭的气化受传质和气化动力学的控制。敏感性分析表明，边界层中的CO氧化和气化动力学显着影响焦炭转化时间，而水煤气变换反应和H ₂氧化作用很小。典型的已粉碎生物质的燃烧条件下对焦炭转化过程中的敏感参数的分析（4％氧气₂，13％CO ₂，13％H ₂ O），示出了炭气化反应显著有助于焦炭转化，特别是对于毫米波尺寸的高温生物质炭颗粒。