科威特减压渣油及其窄馏分接触热裂化反应规律研究

STUDY ON CONTACT CRACKING OF KUWAIT VACUUM RESIDUE AND ITS NARROW FRACTIONS

采用戊烷超临界萃取方法将科威特减压渣油分为4个窄馏分,并采用核磁共振、质谱等方法对渣油和窄馏分进行了表征,在固定流化床评价装置上采用惰性流化粒子对科威特减压渣油及其窄馏分的接触热裂化反应规律进行研究。结果表明:干气产率随原料中五环及五环以上芳烃含量增加而增大,焦炭产率随原料芳碳率的升高而升高,液体产率随原料中(链烷碳率+环烷碳率)的增加而增加,且均呈线性关系;原料中五环及五环以上芳烃含量越高,在相同工艺条件下裂解深度指标(CH4/C3H6质量比)越大,两者具有很好的线性关系;随原料变重,氢气选择性下降,甲烷、乙烷、丙烷、丁烷等烷烃的选择性增加;原料性质越差,在干气和焦炭中单位转化率的氢分布比例越大,液体产物中氢分布比例越小。

Kuwait vacuum residue is cut to 4 narrow fractions by SFEF and the residue and all the fractions are characterized by NMR and mass spectrum. The experiments of contact thermal cracking re- action of Kuwait residue and its fractions were conducted over inert particle in a laboratory fixed fluid- ized reactor. The results show that the yields of dry gas, coke and liquid increase linearly with the con- tent of cores containing five or more aromatic rings, fA and （fN＋fp）,respectively. At the same process condition, the value of CH4/C3 H6 as the index of cracking severity of feeds rises linearly with the con- tent of cores containing five or more aromatic rings. The heavier the feed is, the lower the selectivity oI hydrogen is, while the methane, ethane, propane and butane have the opposite results. The proportion of the hydrogen distributed in dry gas and coke is higher with the feed becoming heavier and meanwhile the proportion is lower in liquid.