CO_(2)/H_(2)O气氛下红沙泉煤中碱(土)金属的分布及其气化反应特性

Distribution of alkaline(earth)metals and gasification reaction characteristics of HSQ coal under CO_(2)/H_(2)O atmosphere

使用高温气化固定床实验系统开展了CO_(2)/H_(2)O气化条件下,红沙泉煤中碱(土)金属(AAEMs)的分布情况及其对煤焦气化反应活性的影响。结果表明,气化温度低于灰熔点温度时,Na元素在煤焦表面离散分布,不存在明显的团簇富集现象;气化温度高于灰熔点温度时,Na元素在煤焦表面表现出轻微的富集现象。气化过程中K元素离散分布在煤焦表面,Ca和Mg元素在煤焦表面的富集现象比较明显,含Ca、Mg类矿物迁移团簇在煤焦表面凹陷处,形成尺寸较大的灰球,Ca、Mg元素在分布上存在一定的依赖性。气化残余焦的表观活化能和指前因子随着碳转化率的增加而增加,煤焦的反应活性变低。

The distributions of Hongshaquan coal's alkaline(earth)metals and their influence on coal char gasification reaction activity under different gasification conditions were investigated in a high-temperature gasification fixed-bed experimental system.The results showed that the Na discretely distributed on the char surface at low temperature,while it showed a slight aggregation phenomenon when the gasification temperature was higher than ash fusion temperature.During the gasification process,the K was evenly distributed on the char surface.The enrichment of Ca and Mg elements on the surface of coal char was relatively obvious.The migration clusters of calcium-containing and magnesium-containing minerals formed large-sized ash sphere in the depressions on the surface of coal char.There was a certain dependence on the distribution of the above two elements.As the carbon conversion increased,the apparent activation energy and pre-exponential factor all increased,and the reactivity of coal char became worse.