溶剂萃取对脱除加氢煤焦油馏分中芳烃组分的影响

Effects of Solvent Extraction on Removal Aromatic Components from Tar Hydrogenation Products

以中低温煤焦油固定床加氢柴油210℃～280℃馏分油为原料,研究了不同萃取剂对脱除芳烃组分的影响.通过计算两种溶剂的芳烃分配系数、芳烃选择性系数及萃余油收率,评价了两种萃取剂在不同剂油比(溶剂与210℃～280℃馏分油的体积比,下同)条件下的萃取效果,结果表明:二甲基亚砜(DMSO)对一环芳烃、二环芳烃和芴系等各类芳烃组分均具有较高的选择性,在剂油比为9∶1时,其总芳烃选择性系数为60.928,萃余油收率高达76.02%;N,N-二甲基甲酰胺(DMF)对各类芳烃组分的溶解性优于DMSO对各类芳烃组分的溶解性,但芳烃选择性较差,因此萃余油收率较低,剂油比为9∶1时,萃余油收率仅为14.75%;根据两种萃取剂性质特点,采用DMSO为主萃取剂,添加20%(体积分数)的DMF复配为复合萃取剂.实验考查了复合萃取剂效果并分析了原因,结果表明:复合萃取剂溶解性能提高明显,总芳烃萃取率由56.54%提高到75.36%;通过GC-MS分析可知,使用复合萃取剂时,各组分萃取率均有明显提高,其中非芳烃组分的萃取率提升幅度明显高于芳烃组分的萃取率提升幅度.实验研究了多级萃取对芳烃脱除的影响,结果表明,经过三级萃取后,萃余油中总芳烃质量分数小于5%,满足环保型油墨溶剂油要求.

Using 210 ℃-280 ℃ distillate oil of medium-low temperature tar fixed bed hydrogenated diesel oil as material,the effects of different extractants on the removal of aromatic compounds were studied.The extraction efficiency of two kinds of extractant under different solvent-to-oil ratio（volume ratio of solvent to 210 ℃-280 ℃ distillate oil,the same below）was evaluated by calculating the partition coefficient,selectivity coefficient and extraction yield of two solvents.The results show that DMSO has high selectivity for monocyclic aromatics,bicyclic aromatics and fluorene series aromatic components.The selectivity coefficient of total aromatics is 60.928 and the yield of raffinate oil is 76.02% when the solvent to oil ratio is 9∶1.The solubility of DMF is better than that of DMSO,but its selectivity is poor,so the yield of raffinate oil is low,which is only 14.75% under ratio 9∶1.According to the characteristics of the two extractants,DMSO is used as the main extractant and 20%（volume fraction）DMF is added to the composite extractant.The effect of the composite extractant is investigated and the reason is analyzed.The results show that the solubility of composite extractant increases obviously,and the extraction rate of total aromatics increases from 56.54%to 75.36%.By GC-MS analysis,it is found that the extraction rate of each component is obviously improved when composite extractant is used,and the extraction rate of non-aromatics is higher than that of aromatics.The effect of multistage extraction on the removal of aromatics is studied in the experiment.The results show that the mass fraction of total aromatics in the extracted oil is less than 5% after three stage extraction,which meets the requirement of environment-friendly ink solvent oil.