Abstract: In this work, three kinds of non-petroleum solvents (coal tar light oil, shale oil, and coal tar diesel) were used as solvents for viscosity reduction of residue oil. The influence of temperature, solvent, and solvent/residue ratio on viscosity reduction of residue was tested. A theoretical equation for liquid viscosity derived from the differential equation for a model of argon gas is extended to describe the temperature-viscosity relationship of blending mixture of residue and solvent, and establish a residue dilution model. The test results show that three kinds of non-petroleum-based solvents can be used to reduce the viscosity of residue. The viscosity of the mixture is reduced more significantly as the blending ratio increases. At a solvent/residue ratio of 0.3, the shale oil and coal tar light oil exhibit a better viscosity reduction effect. It is believed that the asphaltene association by solvent may be the important factor for viscosity reduction of residue. The established model proves that the calculated values are in good agreement with observations and the model parameters reflect the average molecular composition and the relationship of temperature and viscosity of blending residue.

Key words: residue, viscosity reduction, viscosity model, mechanism, non-petroleum solvent