中温热解焦油重馏分悬浮床加氢裂化的研究

以中温热解煤焦油为原料,对其性质进行了分析,其中,350℃重质馏分中胶质含量30.88%,沥青质含量37.27%,四氢呋喃不溶物3.36%,属于常规固定床加氢裂化难以直接处理的馏分。合成了一种Mo系超分散催化剂,采用FT-IR、XPS、XRD、SEM和TEM等对催化剂进行了表征,催化剂中含有Mo=O和Mo-S特征结构,活性金属的硫化率为84.34%,在体系中具有优良的分散性,在反应体系内原位分解为超分散MoS_2颗粒;在0.25 t/d连续装置上进行了热解重油悬浮床加氢裂化实验研究,考察了反应条件对产物分布情况和结焦率的影响,得出适宜的反应条件为19 MPa,440℃,催化剂的添加量为300 mg/kg;此条件下石脑油收率24.47%,柴油馏分收率49.71%,结焦率1.32%。

Study on suspension bed hydrocracking of medium temperature pyrolytic heavy tar fraction

The medium temperature pyrolytic coal tar was used as raw material and was analyzed, in which the fraction with boiling point >350℃ that contains the resin of 30.88%, the asphaltene of 37.27% and the tetrahydrofuran insolubles of 3.36% is difficult to hydrocrack directly by conventional fixed bed. A Mo-based ultra-dispersed catalyst was synthesized, and characterized by FT-IR, XPS, XRD, SEM and TEM, etc. The catalyst contains Mo=O and Mo-S characteristic structure and has an excellent dispersibility in the reaction system, and the vulcanization ratio of molybdenum reaches 84.34%. The catalyst can be decomposed into hyper dispersive MoS₂ particle in the reaction system. The suspension bed hydrocracking experiments were carried out in a 0.25 t/d continuous unit with heavy fraction of tar. Moreover, the effects of reaction conditions on product distribution and coking rate were investigated. The optimum reaction conditions were 19 MPa, 440℃ and 300 mg/kg of catalyst addition. Under these conditions, the naphtha yield is 24.47%, the diesel fraction yield is 49.71%, and the coking rate is 1.32%.