Abstract: The influences of operation conditions on the iron base chemical looping hydrogen generation process for adjusting H2/CO ratio in syngas and hydrogen generation for Fischer-Tropsch (FT) synthesis were studied. The results show that when the H2/CO ratio is 0.5 in the syngas, the H2/CO ratio in exhaust gas varies from 0.87 to 0.53 as the temperature increases from 500 to 800℃. By adding suitable amount of steam in the reduction stage, the adjusting capacity can be enhanced dramatically and the hydrogen amount in the oxidation stage increases. The additional steam in the reduction stage can also restrain carbon deposition effectively and make the hydrogen purity approach 100%. The reactivity and recyclability can be enhanced by adding graphite as pore-forming additive. After 6 cycles, the practical hydrogen amount can still reach 40% of the theoretical amount for the particles with the graphite as additive (20% for original particles) and reserve pore structure after reaction while the particles without graphite are almost completely sintered.

Key words: chemical looping, hydrogen, synga, H2/CO ratio, carbon deposition

摘要： 利用固定床反应器考察了实验参数对调节用于费托合成的合成气中H2/CO及产氢的影响. 结果表明，500~800℃条件下，合成气(H2/CO为0.5)经过固定床反应器时，出口H2/CO可达0.87~0.53；通过在还原阶段通入适量水蒸汽，可有效提高调节H2/CO的能力，且能增加氧化阶段的产氢量. 此外，还原阶段加入水蒸汽还能有效抑制积碳生成，所制H2纯度接近100%. 在载氧体颗粒中加入石墨作为扩孔剂，可增强颗粒反应活性和稳定性，经过6个循环后，实际产氢量仍保持在理论产氢量的40%以上(不加石墨仅为20%)且仍保持一定的孔结构，而未加石墨的颗粒几乎完全烧结.

关键词: 化学链, 氢气, 合成气, 氢碳比, 积碳