K2CO3 catalyzed steam gasification of ash-free coal. Studying the effect of temperature on carbon conversion and gas production rate using a drop-down reactor
K2CO3 catalyzed steam gasification of ash-free coal. Studying the effect of temperature on carbon conversion and gas production rate using a drop-down reactor
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DOI：
10.1016/j.fuel.2014.03.014
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发表时间：
2014-07
期刊：
影响因子：
7.4
通讯作者：
Jan Kopyscinski;Jill Lam;C. Mims;J. Hill
中科院分区：
文献类型：
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作者：
Jan Kopyscinski;Jill Lam;C. Mims;J. Hill
在新设计的下拉式反应器中进行了无灰煤加碳酸钾和不加碳酸钾的水蒸气气化实验。在600-800℃和2.5℃的范围内，研究了碳转化率和产气率与温度的关系。在有钾催化剂存在的情况下，700℃下的气化速度大约快20倍。气化温度可降低125℃，625℃时的催化气化速率与750℃时的非催化气化速率基本相同，表观活化能从268kJ·∼·−-1降至161kJ·mol·mol-1。无灰煤和无灰煤的水-气变换反应均处于平衡状态。在低温下，碳基质直接加氢生成了相当数量的甲烷。甲烷的形成与COx的产生是脱钩的。
Steam gasification experiments of ash-free coal with and without potassium carbonate were performed in a newly designed drop-down reactor. The temperature dependency on the carbon conversion and gas production rates was investigated in a range of 600–800 °C and 2.5 bar. The gasification rate at 700 °C was approximately 20 times faster in the presence of the potassium catalysts. The gasification temperature could be lowered by ∼125 °C. For example, at 625 °C the catalyzed gasification rate was essentially the same as for uncatalyzed rate at 750 °C. In addition, the catalyst reduced the apparent activation energy from 268 to 161 kJ mol−1. The water–gas-shift reaction was in equilibrium for both the uncatalyzed and catalyzed gasification of the ash-free coal samples. At low temperatures, a considerable amount of methane was formed through direct hydrogenation of the carbon substrate. Methane formation was decoupled from the COxproduction.