密度和折光率是油品的基本物性,也是油品溶剂精制设计过程所需的基础数据.采用二甲基亚砜(DMSO)为萃取剂精制克拉玛依环烷基减四线馏分油,考察了萃取温度和剂油比的影响,并对溶剂精制过程中密度与折光率间的关系模型及二者与温度之间的定量关系进行探讨检验,验证不同关联式对油品性质预测的准确性.结果表明,DMSO可使萃取油芳香烃质量分数达到 80%以上,改进后的二次方型关联式可较好地描述环烷基油品的密度与折光率间的关系.不同温度下密度和折光率比值基本呈正比,但随着温度的升高正比变化关系的准确性变差;Yarranton等提出的密度、折光率与温度的关系式可准确地预测萃余油密度和折光率随温度的变化.
Density and refractive index as essential data in the design of solvent refining process are fundamental physical properties of oils.Solvent extraction of Karamay naphthenic vacuum fourth distillates by dimethyl sulfoxide(DMSO)was carried out to investigate the effects of extraction temperature and solvent-oil ratio.Furthermore,the relationship between density and refractive index as well as the quantitative variation of these properties with temperature during solvent refining were examined and evaluated in order to check the reliability of different correlations in property prediction.The results indicate that the aromatic content of the extracts can reach over 80%in the case of DMSO,and the modified quadratic correlation adequately describes the relationship between density and refractive index of naphthenic oils.Additionally,the density and refractive index of the naphthenic oils illustrates an approximately proportional relationship with temperature.Nonetheless,the proportional relationship is weakened with increasing temperature.The relationship between density/refractive index and temperature proposed by Yarranton et al.precisely predicts the density and refractive index of raffinates at different temperatures.