Effect of temperature and molecular weight of n-alkane precipitants on asphaltene precipitation

The effect of temperature, molecular weight of n-alkane precipitants and dilution ratio on asphaltene precipitation in a Chinese crude oil have been studied experimentally. The amounts of asphaltene precipitation at four temperatures in the temperature range of 293–338 K have been measured using seven n-alkanes as precipitants. The onset points at 293 K for all n-alkane precipitants have been determined by direct experimental measurements and by an extrapolation method based on scaling equations. perimental data obtained in this work were used to test the temperature-dependent scaling equations recently proposed by Rassamdana et al. [Energy & Fuels 13 (1999) 176]. The test results showed that the proposed new scaling equations are adequate for correlating and predicting the asphaltene precipitation data measured at different temperatures using various n-alkane precipitants.