Enhanced fluidized bed methanation over a Ni/Al2O3 catalyst for production of synthetic natural gas
Enhanced fluidized bed methanation over a Ni/Al2O3 catalyst for production of synthetic natural gas
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DOI：
10.1016/j.cej.2013.01.005
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发表时间：
2013-03
影响因子：
15.1
通讯作者：
Jun Li;Li Zhou;Li Pengcheng;Qingshan Zhu;Jiajian Gao;Fangna Gu;F. Su
中科院分区：
文献类型：
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作者：
Jun Li;Li Zhou;Li Pengcheng;Qingshan Zhu;Jiajian Gao;Fangna Gu;F. Su
在流态化反应器中系统考察了典型的合成天然气催化剂Ni/Al2O3的流态化行为和CO甲烷化反应性能。结果表明，催化剂的甲烷化性能在很大程度上取决于沸腾床甲烷化反应器的流态化质量。纯Ni/Al_2O_3催化剂的颗粒尺寸在10~100μm之间时不能流态化，但添加Al_2O_3颗粒可以显著改善催化剂的流态化。添加Al_2O_3颗粒也显著提高了床层中的甲烷化反应，添加Al_2O_3的床层中甲烷的产率和选择性明显高于未添加Al_2O_3的。CO甲烷化反应受两种不同的机理控制，即较低温度范围(250-330℃)的表面反应控制和较高温度范围(>；330℃)的外扩散控制。稳定性试验表明，与固定床甲烷化反应器相比，沸腾床甲烷化反应器具有更高的CO转化率、CH4选择性和产率，在高温下具有更好的抗碳性，有利于高温水蒸气的回收。
The fluidization behavior and CO methanation performance over a typical Ni/Al2O3catalyst for synthetic natural gas production was systematically investigated in a fluidized bed reactor. The results indicated that the methanation performance of the catalyst depends, to a large extent, on the fluidization quality in the fluidized-bed methanation reactor. The pure Ni/Al2O3catalyst with the particle sizes of 10–100μm failed to fluid, but the fluidization can be significantly improved by adding Al2O3particles. The methanation reaction in the fluidized bed reactor was also substantially improved by adding Al2O3particles, and the yield and selectivity of CH4in the fluidized bed with Al2O3addition were much higher than those of without Al2O3addition. The CO methanation reaction was controlled by two different mechanisms, i.e. the surface reaction controlling in lower temperature range (250–330°C) and external diffusion controlling in higher temperature range (>330°C). Stability test demonstrated that the fluidized bed methanation reactor showed higher CO conversion, CH4selectivity and yield, and more excellent carbon resistance than the fixed bed methanation reactor under high temperature, which is beneficial for reclaiming the high temperature steam.