Abstract: Hot gas filtration with raw syngas was continuously tested for 100 hours on a pilot scale purification system,the influence of biomass type,after-burning and back blow on pressure drops and temperatures of dust filter were studied,and the concentrations of gas component,tar and dust in the raw syngas and purified syngas were analyzed. It was found that compared with filtration with syngas from wood chip gasification,the pressure drop of the filter increased by 1200-1500Pa while filtration with syngas from co-gasification of pellet(25%mass)and wood chip(75%)the optimal temperature of filter was 450-550℃;after-burning with air was a more effective way to decrease the filter pressure drop than back blowing with N₂. The optimal flow rate of after-burning air was 10-12m³/h when the flow of syngas was 260-400m³/h;and the filter pressure drop remained at around 1200Pa. It was concluded that the pilot filtration system could continuously and stably run for 100 hours. The dust content in purified syngas was as low as 10-40mg/m³. The dust and tar removal efficiency was 92.3% to 99.8% and 31.0% to 92.5%,respectively. The filtration did not reduce the concentration of combustiblegases in purified syngas significantly.

Key words: biomass, gasification, filtration, dust, tar

摘要： 生物质气化得到的粗燃气含有焦油和粉尘杂质，两者形成的混合物在净化装置的高温区易碳化结焦，在低温区容易凝结成团，因此常规的除尘技术并不适用。针对该问题，本文开发了粗燃气高温陶瓷除尘技术，并考察了生物质原料种类、补燃及反吹等工艺条件对除尘室压降和运行温度的影响。试验结果表明：与木片单独气化比较，采用25%成型颗粒燃料+75%木片（质量比）混合气化可导致除尘室阻力上升1200~1500Pa；高温除尘室最佳操作温度为450~550℃，补燃较反吹是降低除尘室压降更有效的手段，当燃气处理量为260~400m³/h时，补燃空气的最佳流量为10~12m³/h，此条件下可使除尘室压降稳定在1200Pa左右。陶瓷管燃气除尘设备可实现100h连续稳定运行，除尘器出口粉尘浓度为10~40mg/m³，粉尘脱除率92.3%~99.8%，焦油脱除率为31.0%~92.5%，且补燃除尘后可燃气体组分浓度基本保持不变。

关键词: 生物质, 气化, 过滤, 粉尘, 焦油