重油组分稀溶液比浓黏度-浓度曲线的测定及变化规律

MEASUREMENT AND VARIATION OF REDUCED VISCOSITY-CONCENTRATION CURVE FOR DILUTE SOLUTION OF HEAVY OIL FRACTIONS

利用液-固吸附色谱柱将重油分离成四组分或八组分;采用等体积黏度测定法测定了重油各组分稀溶液的黏度,绘制了比浓黏度-浓度曲线,并对其变化规律进行解释;提出了采用多点法和单点法计算重油组分特性黏度的方法。结果表明,重油各组分稀溶液的比浓黏度-浓度曲线均为水平线,满足Einstein定律,与高分子稀溶液比浓黏度-浓度曲线满足Huggins定律的情况不同,这是由于重油分子在稀溶液中呈刚体结构,分子间力不足以引起重油分子的形态尺寸变化的缘故。根据重油各组分稀溶液的比浓黏度-浓度曲线可以得到其特性黏度。

Two kinds of heavy oils were separated into four and eight fractions by liquid-solid adsorption chromatography, respectively. The viscosity of the dilute solution of heavy oil fraction was determined by using iso-volume viscosity determination method. The reduced viscosityconcentration curves for all the heavy oil fractions were drawn, and the variation rule of the viscosity-concentration curve was studied. The results indicated that the reduced viscosityconcentration curve for dilute solution of each heavy oil fraction was a horizontal line to follow the Einstein law, which was quietly different from the reduced viscosity-concentration curve of macromoleeule dilute solution commonly following the Huggins law. In dilute solution of heavy oil fraction, heavy oil molecules were considered as rigid entities, and intermolecular force was not strong enough to change the shape and size of these molecules. Based on the horizontal line characteristics of reduced viscosity-concentration curve, the novel calculation methods of intrinsic viscosity of heavy oil fraction were proposed, including multi-point method and single-point method.