S Zorb精制汽油终馏点上升原因分析

CAUSE ANALYSIS OF FINAL BOILING POINT RISING OF GASOLINE PRODUCT IN S Zorb PROCESS

针对S Zorb工艺生产清洁汽油过程中普遍存在产品汽油终馏点升高的问题,以催化裂化汽油和直馏汽油为原料,在小型固定床反应器上考察了S Zorb吸附脱硫反应前后汽油馏程、组成的变化。结果表明:经S Zorb吸附脱硫后,产品汽油的终馏点随反应温度的升高而上升;产品油重组分中芳烃含量普遍增加,导致烃类碳数增加的烯烃的存在以及高沸点芳烃含量增加是导致终馏点上升的重要因素;C5以下轻组分在S Zorb过程中主要发生加氢反应,不会生成芳烃。反应过程中除发生加氢反应外,还发生了链烷烃环化和环烷烃脱氢芳构化反应,在实验室条件下,总体表现为碳氢摩尔比变化不大。

The S Zorb process can produce low sulfur gasoline.However,the final boiling point（FBP）of the product gasoline rises.To find the reason,the boiling ranges and compositions of the products before and after S Zorb process were investigated in a micro-fixed reactor using FCC gasoline and straight-run gasoline as feedstocks from SINOPEC Cangzhou Company and from Yanshan Refinery,respectively.Results show that the FBP of the product rises with the rise of the reaction temperature.The increase of aromatic hydrocarbons and high boiling point aromatics in heavy distillates,the existence of olefins which cause the increase of carbon number of the components are the primary reasons of the FBP rising.In addition to the hydrogenation of hydrocarbons 〈C5,the cyclization of alkanes and dehydro-aromatization of naphthene occurs as well.However,under laboratory conditions,the mole ratios of H/C change little.