. 燃煤烟气喷射 改性稻壳焦脱汞试验研究 . -

为研究燃煤烟气条件下,喷射烟气温度和吸附剂喷射量对汞脱除效率的影响,采用1%的NH4Br溶液对稻壳焦浸渍改性,制备NH4Br改性稻壳焦(Br-RHC)脱汞吸附剂,并通过比表面积及孔隙率分析仪对改性前后吸附剂的孔隙结构进行表征;在0. 3 MW燃煤循环流化床中试装置上进行了吸附剂烟道喷射脱汞试验。结果表明:吸附剂改性后的比表面积、微孔容积与总孔容积均有一定程度的增加;喷射脱汞效率随喷射量的增大而增加并趋于稳定,喷射量由0. 3 kg/h升高为0. 5 kg/h时,脱汞效率从69. 36%升至79. 44%。喷射脱汞效率随烟气温度的升高而升高,由142℃的57. 74%升高为200℃的79. 48%。生物质稻壳焦经化学改性后可代替活性炭用于燃煤锅炉烟气喷射脱汞技术。 In order to study the effect of flue gas injection temperature and adsorbent injection amount on mercury removal efficiency in coal-fired flue gas,1% NH4Br solution was used to impregnate and modify rice husk coke to prepare mercury removal adsorbent NH4Br modified rice husk coke (Br-RHC).The pore structure of the adsorbent before and after modification was characterized by specific surface area and porosity analyzer,and the experiment of adsorbent injection removing mercury in the flue was carried out in a 0.3 MW coal-fired circulating fluidized bed combustor of pilot scale.The results show that the specific surface area,micropore volume and total pore volume of the adsorbent after modification increase to some extent.The efficiency of injection mercury removal increases with the increase of injection amount and tends to be stable.The mercury removal efficiency increases from 69.36% to 79.44% when the injection amount increases from 0.3 kg/h to 0.5 kg/h.The mercury removal efficiency of the injection process increases with the increase of flue gas temperature,it rose from 57.74% at 142 ℃ to 79.48% at 200 ℃.It is verified that the chemical modified biomass rice husk char is a suitable alternative for activated carbon to be applied into the flue gas injection demercuration technology in coal-fired boilers