固定床渣油加氢催化剂失活的原因分析及对策

固定床渣油加氢技术是重油改质的重要手段,是优化重油催化裂化装置原料的主要措施,而固定床渣油加氢装置催化剂的价格昂贵、使用周期短且不具再生使用性,因此探讨固定床渣油加氢催化剂失活的原因并采取相应的对策,对延长催化剂的使用周期有积极的意义。通过对固定床渣油加氢装置催化剂末期运行的现象、废旧催化剂化学组成等方面的分析,发现导致固定床渣油加氢装置催化剂失活的主要原因是积炭和金属沉积。同时分析催化剂级配装填的比例、催化剂硫化、原料油的性质和反应温度的分布等因素对固定床渣油加氢催化剂失活的影响,提出了采用抗积炭和容垢能力高的催化剂,进行合理的催化剂级配装填,控制好原料的性质,调整各床层反应温度的匹配分布和控制好催化剂开工条件等措施,可有效延长催化剂的使用寿命。

Causes of deactivation of fixed-bed residue hydrotreating catalysts and countermeasures

Fixed-bed residue hydrogenation is an important process to upgrade heavy oil and a major measure to optimize feedstock of heavy oil fluidized catalytic cracking units.However,the catalysts for the said process are expensive in addition to the short service life as well as the non-regenerative nature,which makes it worthy to study the causes of fixed-bed residue hydrogenation catalyst deactivation and to take corresponding countermeasures to extend the catalysts life.The analysis of EOR performances of fixed-bed residue hydrotreating catalysts and chemical compositions of spent catalysts has found out that the main causes of catalyst deactivation are carbon and metal depositions.The impacts of proportion of catalyst graded loading,catalyst pre-sulfiding,feedstock properties and distribution of reaction temperatures on catalyst deactivation are studied.The use of coke-deposition-resistant catalysts with good deposition capacity,appropriate graded loading of catalysts,good control of feedstocks,good adjustment of bed temperature distribution and good control of catalyst start-up conditions are recommended to extend the service life of catalysts.