Different methods of manufacturing FE-based oxygen carrier particles for reforming via chemical looping, and their effect on performance
Different methods of manufacturing FE-based oxygen carrier particles for reforming via chemical looping, and their effect on performance
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DOI：
10.1007/978-3-642-02682-9_77
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发表时间：
2009-05
影响因子：
12.6
通讯作者：
J. Cleeton;C. D. Bonn;C. Müller;J. S. Dennis;S. Scott
中科院分区：
文献类型：
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作者：
J. Cleeton;C. D. Bonn;C. Müller;J. S. Dennis;S. Scott
化学循环燃烧（CLC）是一种燃烧含碳燃料的方法，它本质上将温室气体二氧化碳与剩余燃烧产物分离，并有可能用于生产高纯度氢气。用于CLC的铁基氧载体已经进行了大量的工作;然而，在重复循环中存在关于铁基氧载体的寿命的问题。在这项工作中，赤铁矿（Fe 2 O3）在850°C的流化床内的N2+CO+ CO2混合物中被还原，并在H2O+ N2混合物中被氧化回磁铁矿（Fe 3 O 4），随后在氧化过程中产生的氢气是令人感兴趣的。随后的循环开始从Fe 3 O 4和两个过渡制度进行了研究; Fe 3 O 4 ParticipFe0.947O和Fe 3 O 4 ParticipFe。通过机械混合和共沉淀产生颗粒。在共沉淀颗粒的情况下，添加Al使得Fe：Al的重量比为9：1，并且研究沉淀期间颗粒的最终pH对反应性的后续影响。本文表明，共沉淀颗粒含有添加剂，如铝可能能够实现一贯的高H2产率之间的Fe 3 O 4和Fe循环时，这些产率是一个函数的比例[CO2][CO]在还原过程中，热力学参数表明，产量应该是独立的这个比例。我们的材料的一个显著特征是，当在Fe 3 O 4和Fe 0.947O之间循环时，通过机械混合制成的颗粒比通过共沉淀制成的颗粒表现得好得多，但当在Fe 3 O 4和Fe之间循环时，比共沉淀颗粒差得多。
Chemical looping combustion (CLC) is a means of combusting carbonaceous fuels, which inherently separates the greenhouse gas carbon dioxide from the remaining combustion products, and has the potential to be used for the production of high-purity hydrogen. Iron-based oxygen carriers for CLC have been subject to considerable work; however, there are issues regarding the lifespan of iron-based oxygen carriers over repeated cycles. In this work, haematite (Fe2O3) was reduced in an N2+CO+CO2mixture within a fluidised bed at 850°C, and oxidised back to magnetite (Fe3O4) in a H2O+N2mixture, with the subsequent yield of hydrogen during oxidation being of interest. Subsequent cycles started from Fe3O4and two transition regimes were studied; Fe3O4↔Fe0.947O and Fe3O4↔Fe. Particles were produced by mechanical mixing and co-precipitation. In the case of co-precipitated particles, Al was added such that the ratio of Fe:Al by weight was 9:1, and the final pH of the particles during precipitation was investigated for its subsequent effect on reactivity. This paper shows that co-precipitated particles containing additives such as Al may be able to achieve consistently high H2yields when cycling between Fe3O4and Fe, and that these yields are a function of the ratio of [CO2] to [CO] during reduction, where thermodynamic arguments suggest that the yield should be independent of this ratio. A striking feature with our materials was that particles made by mechanical mixing performed much better than those made by co-precipitation when cycling between Fe3O4and Fe0.947O, but much worse than co-precipitated particles when cycling between Fe3O4and Fe.