环烷基蜡油加氢裂化多产石脑油和5号工业白油的改造及应用

Revamping and Application of Naphthenic Gas Oil Hydrocracking Unit for Producing More Naphtha and No.5 Industrial Grade White Oil

在多产石脑油条件下,采用环烷基蜡油在4.0Mt/a加氢裂化装置上进行了柴油转产5号工业白油的工业试验,结果表明产品芳烃含量、闪点、运动黏度等难以达到要求。在实验室采用不同的原料切割方案、模拟计算等方法进行了操作方案的研究。通过实施原料降低焦化蜡油含量(由25%降低至10%),增设柴油氮气汽提工艺(可将柴油的初馏点由172℃提高至232℃,使其开口闪点由87℃提高至130℃,同时柴油黏度由3.97mm^(2)/s上涨至4.61mm^(2)/s),优化主分馏塔单元操作等措施,成功产出合格的5号工业白油。进行了主分馏塔冷凝温度的优化,降低了加工损失。对于环烷基进料加氢裂化生产5号工业白油,降低进料氮含量有利于降低芳烃含量;通过氮气汽提分离更利于打破共沸平衡,提高产品闪点,改善初馏脱空。

Under the conditions of producing more naphtha,naphthenic gas oil was used in the industrial test of producing No.5 industrial grade white oil on a 4.0Mt/a hydrocracking unit.The results showed that the aromatics content,flash point and kinematic viscosity of the product could not meet the requirements.In the laboratory,different feed cutting schemes and simulation calculation methods were used to study the operation schemes.By reducing the coker gas oil content of the feed from 25% to 10%,adding diesel nitrogen stripping process to increase the initial boiling point of diesel from 172℃ to 232℃,increase the opening flash point of diesel from 87℃ to 130℃ and increase the diesel viscosity from 3.97mm^(2)/s to 4.61mm^(2)/s,and optimizing the operation of main fractionator unit,on-spec No.5 industrial grade white oil was successfully produced.The condensation temperature of the main fractionator was optimized to reduce the processing loss.For the hydrocracking of naphthenic feed to produce No.5 industrial grade white oil,reducing the nitrogen content of feed is beneficial to reducing the aromatics content.Nitrogen stripping is more conducive to breaking the azeotropic equilibrium,increasing the flash point of product and improving the distillation gap.