固定床渣油加氢催化剂运转初期失活规律研究进展

Research progress on deactivation of fixed bed residue hydrogenating catalysts at the initial stage of operation

固定床渣油加氢技术是重油改质的重要手段,而催化剂失活制约着装置运行周期,影响炼厂整体经济效益。渣油加氢过程中,运转初期形成的大量积炭是催化剂快速失活的重要原因。本文主要介绍了运转初期催化剂表面形成积炭的性质、影响积炭形成的因素以及控制积炭的方法等。积炭分为软炭和硬炭,运转初期催化剂表面沉积的积炭以软炭为主,积炭更多地沉积在催化剂外侧,造成孔径向小孔范围迁移,降低孔内活性位利用率;原料油性质、催化剂性质及工艺条件共同决定着催化剂运转初期积炭形成,通过改善原料油性质,优化催化剂及工艺条件可以有效地抑制积炭形成。这对合理使用催化剂,延长装置运转周期及降低炼厂生产成本具有重要意义。

Fixed bed residue hydrogenating technology is a vital way of heavy oil upgrading, butthe deactivation of catalysts restricts the operation cycle of the plant, which affects the overalleconomic benefits of the refinery. At the early stage of operation in residue hydrogenatingprocess, a large number of coke formed on the catalysts＇ surface leads to the rapid deactivationof the catalysts, the properties of the coke, the factors affecting the formation of carbon depositsand the methods of inhibiting the carbon deposition are discussed in this paper. The coke isdivided into soft and refractory coke on the catalysts＇ surface, mainly the soft coke at the initialstage of operatiom the coke is mainly deposited on the outside of the catalysts that results in themigration of pore diameter to the micropore and decreasing the utilization of the active site in thepore The properties of the residue, the catalyst properties and the process conditions togetherdetermine the formation of the coke at the initial stage of operation, but the coke may beinhibited by optimizing these factors. It is of great significance for the rational use of thecatalysts, the extension of the operation cycle and the reduction of refinery production cost.