胜利褐煤及盐酸洗煤热解过程中微结构演变特性研究

Microstructural evolution during pyrolysis of Shengli lignite and hydrochloric acid-demineralized lignite

利用固定床获得胜利褐煤及盐酸洗煤在不同温度条件下的半焦。利用FT-IR、XPS、XRD和Raman等技术对所得半焦进行表征,以研究胜利褐煤及盐酸洗煤热解过程中微结构演变特性。结果表明,盐酸洗煤/焦中含氧结构含量相对较高。随热解温度升高,煤/焦中含氧结构所占比例降低。褐煤热解过程中,盐酸洗脱的矿物质会抑制芳环的有序化排列,同时促进褐煤中芳环簇的缩聚,造成煤焦晶体结构缺陷增加,并对煤焦中侧链的发展不利。

A fixed-bed pyrolysis experiment was adopted to generate solid products of Shengli lignite(SL)and hydrochloric acid-demineralized lignite(SL+)at different temperatures.The structural properties of the chars were investigated by FT-IR,XPS,XRD,and Raman spectroscopy to correlate with the microstructural evolution of SL and SL+during pyrolysis.The results indicated that the concentration of oxygen-containing structures in hydrochloric acid-demineralized lignite/chars was relatively high and decreased with increasing pyrolysis temperature.The mineral components demineralized by hydrochloric acid limited the orderly arrangement of aromatic rings,promoted the condensation of aromatic ring clusters,caused more crystalline defects in the chars,and was adverse to the development of side chains during pyrolysis.