Chemical looping gasification of biomass: Part I. screening Cu-Fe metal oxides as oxygen carrier and optimizing experimental conditions
Chemical looping gasification of biomass: Part I. screening Cu-Fe metal oxides as oxygen carrier and optimizing experimental conditions
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DOI：
10.1016/j.biombioe.2017.11.008
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发表时间：
2018-01-01
影响因子：
6
通讯作者：
Zhao, Haibo
中科院分区：
文献类型：
--
作者：
Niu, Pengjie;Ma, Yuexin;Zhao, Haibo
Fe 2 O3和CuO通常用作生物质化学链气化（CLG）的氧载体（OC）。然而，Fe 2 O3显示出相对低的反应性，即使它是便宜的，而CuO表现出太高的反应性而不能与所产生的合成气反应，并且在高温下遭受烧结问题。本文是一个两部分的系列工作的第一部分，其中合成OC的溶胶-凝胶燃烧合成（SGCS）方法制备的Cu-Fe氧化物的生物质衍生CLG过程中提出的。利用热重分析仪（TGA）首次研究了木屑与Cu-Fe系有机碳的重整反应性。结果表明，铜负载率越高的铜铁氧化物对木屑的反应活性越好。随后，在间歇流化床反应器中，评价了五种铜铁氧化物在生物质CLG过程中的性能。通过比较产物气体组分、气体产率、焦油产率和碳转化率，选择Cu 5 Fe 5 OC（50 mol.% CuO + 50摩尔% Fe 2 O3）显示出最佳的综合CLG性能。进一步研究了水蒸气与生物质的比例（S/B）、温度和载氧体与生物质的比例（O/B）对Cu 5 Fe 5性能的影响。当S/B为0.75、温度为800 ℃且O/B为0.2时，可以获得最佳操作状态。XRD和ESEM表征结果表明，Fe 2 O3的加入显著提高了CuO基OC的抗烧结性，且Fe 2 O3中CuO组分的存在有利于改善OC的孔结构。
Fe2O3 and CuO are commonly used as oxygen carrier (OC) for chemical looping gasification (CLG) of biomass. However, Fe2O3 shows relatively low reactivity even though it is cheap, whilst CuO presents too high reactivity to react with the produced syngas and suffers from sintering problem at high temperatures. This paper is the first part of a two-part series work, where synthetic OCs of bimetallic Cu-Fe oxides prepared by the sol-gel combustion synthesis (SGCS) method were proposed for the biomass-derived CLG process. The reforming reactivity of Cu-Fe OCs with sawdust was first investigated in a thermogravimetric analyzer (TGA). The result indicated that Cu-Fe OCs with higher Cu loading ratio demonstrated better reactivity towards sawdust. Subsequently, the performances of five kinds of Cu-Fe OCs in biomass-derived CLG process were evaluated in a batch fluidized-bed reactor. By comparing the product gas components, gas yield, tar yield and carbon conversion, Cu5Fe5 OC (50 mol.% CuO + 50 mol.% Fe2O3) was found to demonstrate the best comprehensive CLG performance. The effects of steam to biomass ratio (S/B), temperature and oxygen carrier to biomass ratio (O/B) on the performance of Cu5Fe5 were further investigated. The optimum operation state can be attained when the S/B was 0.75, the temperature was 800 degrees C and the O/B was 0.2. The results of XRD and ESEM characterization showed that the addition of Fe2O3 into CuO-based OC significantly improved the sintering resistance, and the existence of CuO component in Fe2O3 was conductive to improving the porous structure of OC.