高钠煤化学链燃烧特性及煤焦气化反应动力学研究

Chemical looping combustion of high-sodium coal and gasification kinetics of coal char

采用连续提取法对新疆准东高钠煤进行萃取处理,制备含有不同存在形式钠元素的准东煤样品,在小型流化床上考察了水溶性钠、醋酸铵溶性钠和稀盐酸溶性钠对于准东煤化学链燃烧特性的影响。结果表明,去除水溶性钠后准东煤化学链燃烧产物中含碳气体相对浓度显著提高,相同时刻碳转化率明显提高。而经过醋酸铵和稀盐酸处理后的准东煤相比未处理的准东煤,其化学链燃烧反应性能显著降低。对四种不同处理程度准东煤焦的等温气化反应进行动力学分析表明,WW-ZDJ与水蒸气的气化反应的活化能最小,HAW-ZDJ的气化反应活化能最大。水溶性钠对于准东煤化学链燃烧过程具有抑制作用,而醋酸铵和稀盐酸溶性的钠在准东煤的化学链燃烧过程中促进作用显著。

The continuous extraction method was used to extract the Zhundong high-sodium coal from Xinjiang, and the Zhundong coal samples containing different forms of sodium were prepared. The water-soluble sodium, ammonium acetate-soluble sodium and dilute hydrochloric acid-soluble sodium were investigated on a small fluidized bed. The results showed that the concentrations of carbonaceous gases and carbon conversion efficiency were significantly improved for water-washed ZD (WW-ZD) compared with untreated ZD. However, poor reaction properties of ammonium acetate washed ZD (AAW-ZD) and hydrochloric acid washed ZD (HAW-ZD) were obtained during a CLC process. The kinetics analysis on the isothermal gasification of ZD char with different extraction level was also investigated. The results showed that the activation energy of WW-ZD-H 2O was minimal while the activation energy of HAW-ZD-H2O was maximum. It indicated that the H2O-soluble sodium plays a prohibitive role during the CLC of ZD, while the CH3 COONH 4-soluble sodium and HCl-soluble sodium have a distinct promotion effect on CLC combustion performance of ZD.