Critical properties of lower temperature fractions of Shenhua coal liquefaction oil

It is necessary to learn the thermodynamic properties of coalliquefaction oil (CLO) for the liquefaction process design and operation. The software package Aspen Plus was employed to calculate the eight fractions collected at different distillation temperatures lower than 300℃ from Shenhua coal liquefaction oil by the coalliquid module. Meanwhile, the Group Contribution Method (MXXC) was used as a comparable method to acquire the critical data that are validated by the GCMS data. The Aspen Plus calculation results show that the fraction's critical temperature increases with the increasing of the distillation temperature. And the critical pressure grows in the light molecular parts of CLO and then has an inflexion point at 180℃ ~ 200℃. On this turning point it has a great amount of polar compounds detected by GCMS. To assess the consistency of these two methods, the nonparametric test, Smirnove test, was applied to evaluate the cumulative distribution function. The statistic result indicates that the two methods have a same distribution function in the range of 95 percent confidence interval. This means that the critical data calculated from Aspen software could substitute the Group Contribution Method in computing the critical properties of the CLO fractions.