煤直接液化中油煤浆热溶产物的变化

Study on thermally dissolved product changes of coal-oil slurry during direct coal liquefaction

在高压釜中用不同溶剂在不同温度下(250～370℃)考察了神华煤、新庄煤和Wester holt煤热溶产物的变化.结果发现:这3种煤的热溶行为不同,故热溶产物的组成也不同.神华煤以前沥青烯为主,随温度升高,神华煤热溶产物沥青烯生成量变化较为平稳,而前沥青烯生成量逐渐上升,到370℃时前沥青烯的生成量已增加到19 9%.新庄煤在低于310℃时两种中间产物相差不大,在高于310℃以后,沥青烯的生成量增加很快,逐渐占主导作用,其中间产物以沥青烯为主.Westerholt煤的热溶行为与新庄煤类似.采用红外光谱、固体核磁共振对神华煤及其热溶中间产物与抽余煤分析可知,神华煤经热溶处理后,脱除了一些含氧官能团以及某些脂肪烃结构,此外还发现热溶中间产物、抽余煤与原料煤的基本有机结构相似,表明热溶中煤的主体结构尚未发生变化.

The thermally dissolved product changes of Shenhua, Xinzhuang and Westerholt coal were studied in an autoclave using different solvent at different temperature(250～370 ℃).The results show that these three coals have different thermally dissolving behavior, so their intermediate products are different.The asphaltene yield of Shenhua coal changes smoothly, but the preasphaltene yield increases with temperature and reaches to 19.9% at 370 ℃.Preasphaltene is main product of Shenhua coal in this process.The asphaltene yield of Xinzhuang coal is as much as preasphaltene's at the temperature lower than 310 ℃.When temperature is higher than 310 ℃, the asphaltene yield increases quickly and gradually becomes main product.In this process asphaltene is main product of Xinzhuang coal.The behavior of Westerholt coal is similar to Xinzhuang coal.Shenhua coal and its thermally dissolved product as well as extracted residue are analyzed by FTIR spectra and Solid State^(13)C NMR spectra.It is indicated that after thermal extraction the oxygen-functional groups and some aliphatic hydrocarbon of Shenhua coal are removed, furthermore Shenhua coal and its THF extracted residue, THF extract have similar basic structure,indicating that the principle structure of coal is not yet changed during the thermal dissolution.