摘要
采用超临界流体萃取分馏技术 ,在较低温度下 (<2 5 0℃ )将重质油分离成多个窄馏分 ,结合物性及1H NMR、13 C NMR分析确定其化学结构 ,构建重质油馏分的等价分子模型 ,并采用高温模拟蒸馏测定馏分的平均沸点至 95 0K .以Rarey提出的预测纯化合物的基团贡献沸点新方法为基础 ,依据重质油馏分结构参数确定了 12种基团类型 ,原模型基团贡献值保持不变 .用原模型预测俄罗斯渣油馏分沸点 ,与C50 以下的馏分沸点实验值有较好的一致性 ,但对更重馏分误差大 .对原模型沸点与总原子数的变化关系进行了修正 ,修正模型对两种不同基属原油的常压渣油和减压渣油馏分的沸点预测与实验值的平均误差为 1 4 % ,同时能较准确估算高沸点正构烷烃的沸点 ,进一步验证了重质油馏分结构模型的合理性 .结合改进的基团贡献法和超临界流体萃取分馏技术 ,可将重质油沸点预测延伸到 10 5 0K ,碳原子数范围扩展到 10 0个碳原子 。
Heavy oil was separated into over dozen cuts under a lower temperature (1H-NMR, 13C-NMR spectra of the fractions were measured to determine their structure parameters and construct average molecular models. The boiling points of heavy oil fractions were measured up to 950 K. Based on Rarey's group contribution model recently published, 12 groups were defined for heavy oil cuts. It was found that Rarey's model was accurate for below C50 fractions but show higher errors for heavier cuts. The dependence of boiling point on total atom number (except hydrogen) was refitted, while the value of the original group kept unchanged. Estimation for boiling point of two different residua from Russian crude oil and a mixed crude oil of Daqing (70% in mass) with Russian (30% in mass) was found with an average deviation 1.4% in the range of 600 K to 950 K. The Tb prediction of normal alkanes from C3 to C120 was also found in good agreement with literature data. It verifies that the group definition and structure expression for heavy oil fractions are reliable. The group contribution method combined with SFEF can extend Tb estimation up to 1050 K with carbon numbers over 100.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2004年第8期1224-1229,共6页
CIESC Journal
关键词
沸点
预测
基团贡献法
重质油
馏分
Cracking (chemical)
Estimation
Fractionation
Nuclear magnetic resonance
Paraffin oils
Supercritical fluid extraction
