超临界水中氧化钙催化泥炭制氢

HYDROGEN PRODUCTION FROM PEAT IN SUPERCRITICAL WATER IN PRESENCE OF CALCIUM OXIDE

使用间歇式超临界水反应器,以氧化钙作为催化剂和CO_2化学固定剂,详细考察了Ca/C摩尔比、反应温度、停留时间、压力等条件对泥炭在超临界水中转化制氢的影响。在873 K,Ca/C比为0.61时,CO_2几乎被完全固定,在气相产物中只有氢气、甲烷和低碳烃,碳转化率由未添加CaO时的66.6％提高到82.4％,氢气的产率由2.2 mmol·g^(-1)提高到6.9 mmol·g^(-1)。当反应温度由773 K提高到923 K时,泥炭的裂解反应加剧,气体产物的收率由5.5 mmol·g^(-1)提高到19.5 mmol·g^(-1),但是氢气所占比例由55.4％下降到34.8％。与温度相比,压力和在终温停留时间的影响相对较小。

In the present work, hydrogen production from a high-ash peat in supercritical water was investigated using a batch reactor at 773—923 K for 1—30 min under the pressure of 16.8—36.5 MPa. Calcium oxide was added to produce a clean gas free of environmentally unfriendly gases, such as CO_2 and H_2S. At 873 K, a Ca/C molar ratio of 0.61 was required for the complete capture of CO_2. With the fixation of CO_2, trace CO was detected, and the fraction of hydrogen increased from 12% to 46%. Correspondingly, the ca...