炼油厂C_4馏分溶剂抽提脱硫的实验研究

EXPERIMENTAL STUDY ON REMOVING ORGANIC SULFIDE IN REFINERY C_4 FRACTION BY SOLVENT EXTRACTION

以中国石油兰州石化分公司提供的炼油厂C4馏分为原料,采用溶剂抽提法进行脱硫实验,对脱硫剂和脱硫方法进行评选,并对脱硫工艺条件及脱硫剂再生条件进行考察。结果表明:最佳脱硫剂为SW-Ⅰ,C4馏分在SW-Ⅰ中的溶解度仅为6.53×10-5 g/g;最佳脱硫方法为气-液吸收法;在温度为20℃、脱硫剂空速为0.15h-1、C4馏分空速为350h-1和吸收级数为3的条件下,以SW-Ⅰ为脱硫剂,采用气-液吸收法可使C4馏分中有机硫质量分数从198.9gμ/g降到7.5gμ/g,脱硫率为96.23%;对脱硫剂进行热空气汽提再生处理,在再生温度为70℃、脱硫剂空速为1.02h-1和汽提空气空速为291h-1的条件下,再生脱硫剂的脱硫率为96.03%,脱硫剂的再生率可达99.80%。

Using C4 fraction from PetroChina Lanzhou Petrochemical Company as raw material, desulfu- rization tests by solvent extraction were carried out to select optimum desulfurization agent and method, as well as to study the process conditions and agent regeneration conditions. Results showed that SW-I was the optimum desulfurization agent, which had a C4 fraction solubility of 6.53 × 10^-5 g/g only. By comparing liquid-liquid extraction method and gas-liquid absorption method, it was shown that gas-liquid absorption method was more suitable. When adopting 3-stage gas-liquid absorption method and SW-I desulfurization agent, under a reaction temperature of 20℃, an extractant space velocity of 0.15 h^-1 and Ca fraction space velocity of 350 h-1 ,the sulfur content of treated C4 fraction dropped from 198.9 pg/g to 7.5 pg/g with a desulfu- rization rate of 96.23 %. The sulfur-rich absorption agent could be regenerated by hot air stripping. When regeneration temperature was 70℃, solvent space velocity was 1.02 h-1 and hot air space velocity was 291 h^-1, the desulfurization rate of regenerated agent was 96.03 %, indicating that the regeneration rate of the desulfurization agent reached 99.80%.