Development of Iron Oxide Carriers for Chemical Looping Combustion Using Sol-Gel
Development of Iron Oxide Carriers for Chemical Looping Combustion Using Sol-Gel
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DOI：
10.1021/ie100046f
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发表时间：
2010-06-02
影响因子：
4.2
通讯作者：
Mueller, C. R.
中科院分区：
文献类型：
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作者：
Kierzkowska, A. M.;Bohn, C. D.;Mueller, C. R.
使用溶胶-凝胶法制备具有不同质量比的Fe 2 O3和Al 2 O3的复合颗粒，并通过在850 ℃的填充床反应器中的重复还原和氧化循环来检查用于化学链燃烧。与传统的化学链燃烧不同，传统的化学链燃烧还原甲烷中的氧载体并在空气中氧化它，这里的还原气体是CO和N-2的混合物。在蒸汽和N-2的混合物中进行氧化以产生H-2，然后在某些情况下在空气中进行氧化。结果表明：（1）还原为FeO相。（2）对于在10个循环中还原为Fe相，10wt%Al_2 O_3足以在30-40个循环中得到高于0.9的稳定转化率，然而，对于具有10- 20wt%Al_2 O_3的颗粒，转化率下降到低于0.35。(3)对于在40个循环中还原成Fe相，得到40重量%的Al 2 O3，并得到接近0.75的稳定转化率。使用X射线衍射证实了FeO中心点Al 2 O3的形成。N2中的蒸汽，然后是空气，是用于氧化复合载体的推荐顺序，因为可以避免温度升高和颗粒团聚，并且可以实现更高的转化率
Composite particles with different mass ratios of Fe2O3 and Al2O3 were prepared using a sol-gel method and were examined for use in chemical looping combustion through repeated reduction and oxidation cycles in a packed bed reactor at 850 degrees C Unlike traditional chemical looping combustion which reduces an oxygen carrier in methane and oxidizes it in air, the reducing gas here was a mixture of CO and N-2. Oxidation was performed in a mixture of steam and N-2 to produce H-2, followed by oxidation in air in some cases. The results were as follows (1) For reduction to the FeO phase. unsupported Fe2O3 gave stable conversions over 40 cycles and no Al2O3 support was needed (2) For reduction to the Fe phase over 10 cycles, 10 wt % Al2O3 was sufficient to give stable conversions above 0.9 Over 30-40 cycles, however, the conversion for particles with 10-20 wt % Al2O3 dropped below 0 35. (3) For reduction to the Fe phase over 40 cycles, 40 wt % Al2O3 was replied and gave stable conversions near 0.75. The formation of FeO center dot Al2O3 was confirmed using X-ray diffraction. Steam in N-2, followed by air, is the recommended sequence for oxidizing the composite carriers, since temperature excuisions and agglomeration of particles could be avoided and higher conversions could be achieved