神府煤液化油加氢精制过程中硫氮化合物分布的变化

采用实沸点蒸馏对神府煤液化油及其加氢精制油做了馏分切割,并采用GC-PFPD与GC-NCD对液化油与精制油中的硫氮化合物类型进行了分析,研究了液化油加氢精制过程中硫氮化合物分布的变化。结果表明,液化油中硫含量随窄馏分的馏程由低到高呈现"U"型分布,氮的分布基本上随窄馏分沸点温度的升高而增大,氮的含量远高于硫的含量;经过固定床加氢精制后,97%的硫和98.9%的氮得到脱除。液化油中苯并噻吩和二苯并噻吩等二环和三环化合物占93.25%;经过加氢处理之后,硫醇、硫醚、噻吩类等低沸点含硫化合物基本消失,难脱除组分主要以苯并噻吩类、二苯并噻吩类为主。液化油中含氮化合物主要以五元杂环中性氮化物为主,占54.96%;碱性氮化物主要以苯胺类为主,占23.22%,喹啉类相对较少;经过加氢处理之后,脂肪胺类含氮化合物被完全脱除,精制油中残留的氮主要以碱性氮化物喹啉类与苯胺类含氮化合物存在。

Change of sulfur and nitrogen compounds in the direct liquefaction oil from Shenfu coal upon the hydrofining process

The direct liquefaction oil from Shenfu coal and the refined oil through hydrofining were cut into different fractions by true boiling point distillation and the sulfur and nitrogen compounds in each fraction were analyzed by GC-PFPD and GC-NCD; the change in the sulfur and nitrogen compounds in the direct liquefaction oil upon the hydrofining process was then investigated. The results illustrated that the sulfur content in the direct liquefaction oil takes a ‘U’ type distribution with the distillation range from low to high boiling point, whereas the content of nitrogen is far higher than that of sulfur, which increases with the rising of the fraction boiling point. After hydrofining, the sulfur and nitrogen contents are removed by 97% and 98.9%, respectively. Bicyclic and tricyclic compounds such as benzothiophene and dibenzothiophene account for 93.25% of the sulfur compounds in the coal liquefaction oil; after the hydrofining, low boiling point sulfur compounds such as mercaptan, sulfoether and thiophene almost disappear, with benzothiophene and dibenzothiophene as the main sulfur compounds that are difficult to remove. In the coal liquefaction oil, five-membered heterocycle neutral compounds account for 54.96% nitrogen and the portion of basic nitrogen compounds, including mainly anilines with a relatively small amount of quinolones, is 23.22%. After hydrofining, fatty amines are removed completely and the residual nitrogen in the refined oil exists mainly as the basic nitrogen compounds such as quinolones and anilines.