下吸式固定床的生物质H2O/CO2气化数值模拟研究

利用Aspen Plus 软件建立干桦木屑在下吸式固定床气化炉中的气化模型,模拟值与文献实验值吻合良好。利用Aspen Plus的灵敏度分析模块模拟分别以水蒸气（H₂O）和二氧化碳（CO₂）为气化剂时气化剂/生物质碳比（GC值）对气化结果的影响,并结合H₂O、CO₂各自的特点研究其复合气化。结果表明,H₂O气化时可获得富氢煤气,但其净CO₂排放量较高;CO₂气化时碳转化率及冷煤气效率较低,但净CO₂排放量较低;H₂O、CO₂复合气化使碳转化率及冷煤气效率略有降低,但可有效减少气化系统中的净CO₂排放量。

NUMERICAL SIMULATION RESEARCH OF BIOMASS H2O/CO2 GASIFICATION IN DOWNDRAFT FIXED BED

The gasification model of dry birch sawdust in downdraft fixed bed gasifier is established by Aspen Plus software, and the simulation results are in good agreement with the literature values. The sensitivity analysis module of Aspen Plus is used to simulate the effect of gasifier/biomass carbon ratio （GC value） on gasification results when steam （H₂O） and carbon dioxide （CO₂） are used as the gasification agent, and the co-gasification of H₂O and CO₂ is studied in combination with their characteristics. The results show that hydrogen rich gas can be obtained during H₂O gasification, but the net CO₂ emission is higher. Carbon conversion and cold gas efficiency are lower during CO₂ gasification, but net CO₂ emission is lower. The co-gasification of H₂O and CO₂ reduces the carbon conversion and cold gas efficiency slightly, but it effectively reduces the net CO₂ emission in the gasification system.