喷气燃料脱色精制中颗粒白土失活加快的原因分析(Ⅱ)--喷气燃料馏分中有色成分的剖析及不同性质馏分油对白土脱色的影响

先用硅胶对大连石化分公司3号喷气燃料馏分油中的有色组分进行吸附,然后分别用二氯甲烷和甲醇两种脱附剂对已吸附有色组分的硅胶进行脱附,得到两种含有色组分的两种溶液.应用红外光谱和色-质联用分析法对富集的有色组分进行了分析鉴定.分析了不同时期喷气燃料馏分油的性质及其对颗粒白土吸附脱色性能的影响.结果表明,大连石化分公司3号喷气燃料馏分油中的有色组分主要成分为C8～C14醇类、酮类、苯酚、甲酚和多烷基酚类及一些多聚体化合物.脱硫醇塔前进料馏分油的性质差异很小,而脱硫醇塔后馏分油的性质变化很大,颜色显著加深.脱硫醇塔操作末期温度高而引起喷气燃料馏分中不稳定组分的氧化转化导致颜色变深.颗粒白土脱色处理赛氏色值高的喷气燃料馏分油明显比处理赛氏色值低的喷气燃料馏分油的效果要好.脱硫醇塔操作不当造成油品恶化是导致颗粒白土吸附脱色失活很快的主要原因.控制脱硫醇塔乃至蒸馏系统操作条件(特别是温度),对延长颗粒白土的使用时间至关重要.

ANALYSIS OF ACCELERATED DEACTIVATION OF PARTICULATE CLAY IN JET FUEL DISCOLORATION REFINING (Ⅱ)

The color components in 3^#jet fuel fraction are separated by silica gel adsorption and desorption by dichloromethane and methanol in Dalian Petrochemical Company. The properties of jet fuel fractions at different time and their impact on discoloration performance of particulate clay are analyzed by infrared spectrum, chromatography and mass spectrum. The results demonatrate that the color components in 3^# jet fuel are mainly alcohols of C8 -C14, ketone, phynol, creso, multi alkylphenol and some polymer compounds. There is little difference in the properties of feed to the sweetening tower, but the properties of jet fuel fraction vary greatly at the outlet of the sweetening tower and color is significantly darkened, which is the result of oxidation of unsta- ble components at higher temperature at the end of run of sweetening tower. The particulate clay is more effective in treating higher Sayboh jet fuels than in treating the lower ones. The improper sweetening tower operation is the culprit of rapid deactivation of clay. Therefore, the control of operating conditions, especially the temperature, of the sweetening tower and fractionation system is critical to extend the service life of particulate clay.