The Effect of Temperature on Reversibility of Precipitated Asphaltene from Different Origin

فاقد چكيده فارسي

Asphaltene is the heaviest fraction of crude oil. Changes in pressure, temperature and composition can result in the destabilization and precipitation of asphaltene. In order to predict the phase behavior of asphaltene mixture, it is important to determine the reversibility of asphaltene precipitation process. In this paper the effect of temperature and crude oil nature on the reversibility of asphaltene precipitation has been studied. Asphaltene precipitation and re-dissolution has been investigated at temperatures 25°C, 65ºC and 95°C for two different crude oils. Results showed that asphaltene precipitation decreases with temperature increase. Results indicated that asphaltene precipitation is a partially reversible process with respect to temperature change. According to the results asphaltene precipitation is more reversible with respect to temperature change for crude oil A than crude oil B. The aromatic portion of asphaltene molecule is responsible for asphaltene aggregation and precipitation. Therfore, for asphaltene A with lower aromatic portion, the strength of attraction forces between asphaltene molecules is lower and asphaltene precipitation is more reversible.