Abstract:

The effects of different gasification temperature and gas-solid ratio (S/B) on steam gasification reaction of waste pine sawdust were investigated in the self-made steam gasifier by using high-temperature steam gasification technology. Fourier transform infrared spectroscopy (FT-IR) and XRD ray diffraction were employed to analyze the reaction residue and the gasification tar, respectively. The specific surface area and pore characteristics of the reaction residue were separately measured by BET multi-point method and BJH method. The results showed that the increase of steam flow promoted the reactions of steam reforming, carbon reduction, and carbon monoxide conversion. When the ratio of S/B increased from 0.5 to 1.5, the volume fraction of H₂ increased from 52.32% to 67.3% at 900℃,the volume fraction of CO decreased with increasing temperature, and then slightly increased, while the change rule of CO₂ was opposite to CO. The volume fraction of hydrocarbon gases (CH₄ and C_nH_m (n≥2)) of small molecule decreased gradually. In the temperature range of 750-950℃, the gasification reaction increased with increasing temperature. When S/B was 1, the volume fraction of H₂ increased from 31.91% at 750℃ to 62.89% at 900℃, increasing by nearly one time. With the increase of temperature, the weight loss rate of pine briquette fuel increased from 82.91% to 91.27%, the pore structure of the residual solid phase was fully developed, and the average pore diameter decreased from 20.96 nm to 3.76 nm. The content of aliphatic hydrocarbons in gasification tar also increased with increasing temperature, while the content of aromatic hydrocarbon decreased due to the ring opening reaction, which was beneficial to reduce the tar content in the gasification gas.

Key words: waste treatment, biofuel, steam, gasification, solid residues, tar

摘要：

采用自制蒸气气化炉试验系统，以废弃松木屑为原料制作成型颗粒燃料，采用高温水蒸气气化，考察不同气化温度及气料比（S/B）对生物质水蒸气气化反应的影响，利用XRD射线衍射和傅里叶红外图谱分别分析生物质反应残留物及气化焦油，反应残留物的比表面积及空隙特性由BET多点法和BJH法测得。结果表明，蒸汽流量和反应温度有利于促进蒸汽重整、碳还原、CO的变换反应，当S/B由0.5增加到1.5时，温度为900℃，H₂体积分数由52.32%增长到67.3%；随温度升高（750~950℃，S/B=1），松木颗粒的失重率由82.91%升高到91.27%，其微孔结构充分发展，平均孔直径由20.96 nm降低到3.76 nm，焦油中脂肪烃含量增加，芳香烃因发生开环反应使其含量降低，有益于降低气化气中焦油含量。

关键词: 废物处理, 生物燃料, 水蒸气, 气化, 固相残留物, 焦油