可溶小分子对油页岩孔隙结构变化的影响研究

Studies on the Effect of Soluble Small Molecules on the Change of Pore Structure in Oil Shale

选取广东茂名和辽宁抚顺油页岩,利用二氯甲烷和四氢呋喃对酸洗前后的油页岩进行索氏萃取,对萃取液进行GC/MS检测,分析溶出物的组成。对萃取物进行孔隙结构测试,分析酸洗及萃取前后吸附量和孔径结构的变化。通过溶剂作用溶出小分子化合物并改变油页岩孔隙结构,进而得出可溶小分子的贮存方式。结果表明：二氯甲烷主要溶出物种类为烷烃,四氢呋喃主要溶出物种类为含氧小分子化合物。酸洗会使孔隙结构更加丰富,有利于可溶小分子的溶出。油页岩经过溶剂萃取后会使中孔（2-50 nm）和大孔（〉50 nm）数量增多。油页岩孔隙结构中可以贮存可溶小分子,富集在油页岩表面的可溶小分子在溶出时会产生孔洞。可溶小分子在溶出过程中会使油页岩产生新孔或扩大孔尺寸。

The oil shales from Maoming, Guangdong province and Fushun, Liaoning province were selected for hydrochloric acid pickling. Dichloromethane and tetrahydrofuran were used to extract oil shales before and after acid pickling. Compositions of extracts were analyzed by GC/MS. The adsorption capacities before and after extraction and pore structure changes in the extraction residues were tested by pore structure analyzer. The storage manner of small soluble molecules was concluded by the dissolution of small molecules and the change of pore structures. The results show that the major extracts of dichloromethane are alkanes and the major extracts of tetrahydrofuran are oxyenbearing small molecule compounds. Hydrochloric acid pickling will make more pores which conducive to the dissolution of small molecules. The number of medium and large pores in oil shale will increase after solvent extraction. The small soluble molecules can hide in the pore structure of oil shale and the small soluble molecules which gathered on the surface of oil shale can make new pore or expand the pore size while in the process of dissolution.