负载碳酸钠煤焦催化气化反应特性研究

基于热重分析仪开展负载碳酸钠神府烟煤/遵义无烟煤煤焦气化实验,并借助扫描电子显微镜和孔结构及比表面积分析仪表征焦样孔结构及表观结构变化,考察了反应温度(650-800℃)、气化剂(水蒸气、二氧化碳)及碳酸钠负载量(钠离子负载量2.2%、4.4%、6.6%,质量分数)对神府烟煤/遵义无烟煤焦样气化反应活性的影响。结果表明,碳酸钠有利于促进神府/遵义煤热解过程孔隙结构的发展。在二氧化碳气氛下,适宜催化剂负载量使神府烟煤反应活性提高,过多负载催化剂堵塞煤焦内部孔隙结构,使得气化反应活性降低,遵义无烟煤反应活性随负载量增加而提高,两者反应活性均随温度升高而提高。在水蒸气气氛下,神府烟煤/遵义无烟煤在一定条件下反应活性随催化剂负载量增大、温度升高而提高。碳酸钠的添加能够在保证气化反应性的前提下降低气化反应温度和活化能。

Investigation on catalytic gasification reaction characteristics of coal char with Na2CO3

The coal char gasification experiments with Na₂CO₃ as catalyst was investigated on TGA. The pore structure and apparent structure evolution characteristics of char were studied by scanning electron microscopy and pore structure and specific surface area analyzer. The influence of temperature (650-800℃), gasification agent (steam, CO₂) and sodium carbonate loadings (Na⁺ loading amounts 2.2%, 4.4%, 6.6%) on the gasification reactivity of Shenfu bituminous coal (SF) and Zunyi anthracite (ZY) were investigated. The results show that the loading of Na₂CO₃ stimulates the development of pore structure in pyrolysis process. In the atmosphere of CO₂, there was a saturated catalyst capacity for SF and excessive catalyst loading could block internal pore structure of coal, leading to the decrease of gasification reactivity. ZY gasification reactivity increases with catalyst loading, and both SF and ZY gasification reactivity increase with the increase of temperature. In the atmosphere of steam, both SF and ZY gasification reactivity increase with the rise of catalyst loading and temperature. Na₂CO₃ is favorable for the decrease of reaction temperature and activation energy under the desired gasification rate.