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.