Methane reforming over a high temperature stable-NiCoMgOx supported on zirconia–hafnia catalyst
Methane reforming over a high temperature stable-NiCoMgOx supported on zirconia–hafnia catalyst
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DOI：
10.1016/j.cej.2006.05.007
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发表时间：
2006-08
影响因子：
15.1
通讯作者：
V. Choudhary;K. Mondal;T. Choudhary
中科院分区：
文献类型：
--
作者：
V. Choudhary;K. Mondal;T. Choudhary
研究了高温稳定的NiCoMgOx（Ni/Co/Mg：1：0.2：1.2）/ZrO_2催化剂在甲烷催化部分氧化（CPOM）、甲烷氧化水蒸气重整（OSRM）和甲烷氧化CO_2重整（OCRM）反应中的催化性能。该催化剂即使在1400°C下煅烧4小时，也显示出优异的CPOM、OSRM和OCRM反应的活性/选择性。由于其高的热稳定性，在氧重整过程中催化剂床中的热点和/或催化剂表面处占优势的高温对NiCoMgOx/氧化锆-二氧化铈催化剂的催化活性/选择性几乎没有影响或没有影响，因此使得催化剂甚至适合于在绝热条件下操作。虽然对CO的选择性随着反应温度的升高而显著增加，但对H2的选择性的影响程度要小得多。在CPOM反应中CO和H2的选择性被发现随着空速的增加而降低;然而H2的选择性在更大程度上受到影响。对于OSRM过程，H2O/CH 4比深刻地影响H2/CO比和反应热。根据H2O/CH 4的比例，OSRM过程可以在温和的放热，热中性或温和的吸热模式下操作。CO2转化率随着OCRM温度的升高而迅速增加，相应地，OCRM反应的热力学性随着反应温度的升高而降低。在900°C下，OCRM反应是温和放热的并且提供高甲烷转化率和合成气选择性。
The unusually high temperature stable NiCoMgOx(Ni/Co/Mg:1:0.2:1.2)/zirconia–hafnia catalyst has been investigated for syngas generation via the catalytic partial oxidation of methane (CPOM), oxidative steam reforming of methane (OSRM) and oxidative CO2reforming of methane (OCRM) processes. The catalyst, even when calcined at 1400°C for 4h, showed excellent activity/selectivity for the CPOM, OSRM and the OCRM reactions. On account of its high thermal stability, hot spots in the catalyst bed and/or high temperatures prevailing at the catalyst surface during the oxy-reforming processes would have little or no effect on the catalytic activity/selectivity of the NiCoMgOx/zirconia–hafnia catalyst, thus making the catalyst suitable even for operating under adiabatic conditions. While the selectivity for CO increased considerably with increasing reaction temperature for the CPOM process, the selectivity for H2was affected to a much lesser extent. The selectivity for CO and H2in the CPOM reaction was found to decrease with increasing space velocity; the H2selectivity was however affected to a greater extent. For the OSRM process, the H2O/CH4ratio profoundly influenced the H2/CO ratio and the heat of the reaction. Depending on the H2O/CH4ratio, the OSRM process could be operated in a mildly exothermic, thermoneutral or mildly endothermic mode. The CO2conversion increased rapidly with increasing OCRM temperature and correspondingly the exothermicity of the OCRM reaction was found to decrease with increasing reaction temperature. At 900°C, the OCRM reaction was mildly exothermic and provided high methane conversion and syngas selectivity.