THE COLLOIDAL STABILITY OF CRUDE OILS AND CRUDE OIL RESIDUES

A crude oil and three residues of the crude oil processing were investigated by determination of flocculation points of both the product solutions and the original products. Diverse analytical methods were used for characterizing products and their fractions. The evaluation of results was performed by the theory of regular solutions and its extension by Hansen. It was found, that the colloidal disperse phase shows a behaviour similar to that of polymer solutions. The conditions of the destabilization of the colloids can be defined by the critical Flory-Huggins interaction parameter. The solvation and the low soluble part of the asphaltenes have the greatest influence on the colloidal stability. The lowest stability is found for the visbreaking residue. The influence of the crude oil distillation on the colloidal stability is not significant.