Abstract:

The evaluation of biomass chemical looping gasification (CLG) was conducted via a thermogravimetric analyzer and a fixed bed reactor using CoFe₂O₄ as oxygen carrier. The effects of mass ratio (oxygen carrier to biomass), steam content and reaction temperature on the CLG reactivity of biomass were explored and the recyclability of oxygen carrier was also studied. The oxygen carriers of fresh and reacted were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The TGA results indicate that CoFe₂O₄ can provide lattice oxygen to effectively improve the biomass gasification. The optimal performance can be achieved when the mass ratio, steam content and temperature are 0.8, 50%, and 900℃, respectively. After 5 cycles of reaction, high quality syngas can still be obtained. The oxygen carrier can be recycled and there is no obvious sintering and agglomeration.

Key words: biomass, gasification, syngas, chemical looping, CoFe₂O₄

摘要：

在热重分析仪和固定床反应器上对基于CoFe₂O₄载氧体的生物质化学链气化反应特性进行了研究，考察了载氧体与生物质质量比、水蒸气、反应温度对生物质化学链气化反应特性的影响，同时也对载氧体的循环反应性能进行了研究。通过XRD及SEM对新制备的和反应后的载氧体进行了表征。热重结果表明：CoFe₂O₄能够提供晶格氧，有效促进生物质气化。当CoFe₂O₄与生物质质量比为0.8，水蒸气体积分数为50%，温度为900 ℃时，气化反应效果最好。5次循环反应后，仍能获得较高品质的合成气，载氧体能够循环再生且未出现明显烧结团聚。

关键词: 生物质, 气化, 合成气, 化学链, CoFe₂O₄