基于化学链燃烧的转炉放散煤气利用研究

在固定床反应器和热重分析仪上对浸渍法制备的过渡金属氧化物载氧体MnO₂/Al₂O₃、Fe₂O₃/Al₂O₃和CuO/Al₂O₃与转炉放散煤气中CO的反应特性进行了研究,并结合比表面积分析、脉冲化学吸附和扫描电镜等手段表征了CuO/Al₂O₃的循环寿命性能。结果表明,在上述三种载氧体中CuO/Al₂O₃表现出了最佳的反应活性,反应进行2 min时的CO转化率在225℃以上的反应温度下就能达到90%。在350℃、还原反应空速4000 h^-1和氧化反应空速159 h^-1的条件下,CuO/Al₂O₃能够保持良好且稳定的CO脱除性能和机械强度,因而具有良好的循环寿命。据此,提出了基于化学链燃烧的转炉放散煤气利用新工艺,本工艺可安全利用间歇排放的转炉放散煤气,并实现对用户的连续供热。

Utilization of converter off-gas based on chemical-looping combustion

Characteristics of the reduction reactions between transition metal oxide oxygen carriers (OCs) including MnO₂/Al₂O₃, Fe₂O₃/Al₂O₃ and CuO/Al₂O₃ prepared by an impregnation method and CO in converter off-gas were investigated using a fixed bed reactor and a thermogravimetric analyzer. Surface area analysis, pulse chemisorption and scanning electron microscopy were used to characterize the cycle life performance of CuO/Al₂O₃. The results show that CuO/Al₂O₃ exhibit the best reactivity among the three OCs, and the CO conversion at the reaction time of 2 min reach 90% when the reaction temperature is 225℃ or higher. Moreover, CuO/Al₂O₃ can maintain the high and stable performance of CO removal and mechanical strength at 350℃, a gas hourly space velocity (GHSV) of 4000 h^-1 in the reduction reaction and a GHSV of 159 h^-1 in the oxidation reaction, exhibiting an excellent redox cycle life. Based on these findings, a new process based on CLC has been proposed, with which the intermittently discharged converter off-gas can be safely utilized, thereby achieving the continuous heat supply to users.