M.J. Khani, M. Rezaeye
Oil is known as a major source of energy and an economical source of the word. However, depleting world’s crude oil resources has caused increase attention toward heavy oils and bitumen to supply the demand for fuels and petrochemical feedstock. Different techniques have been employed to extract crude and heavy oil with high possible efficiency. As conventional recovery methods currently used have become less efficient, solvent extraction seems to be a suitable alternative and a most cost-efficient recovery process for all recovery methods which requires no water and the solvent is recoverable and reusable. Solvent extraction followed by adsorption also has been found to be one of the competitive processes for recycling of used lubricating oil. Basis of solvent extraction is injecting diluents like naphtha or light oil and some vaporized hydrocarbon solvent, usually, ethane, propane, or butane to the pump to reduce the of the heavy oil to make pumping easier. The petroleum solvents are light section produced from crude oil which is containing paraffinic and aromatic hydrocarbons of petroleum in different ratios. It is obvious that solvent costs and availability are two important factors that determine the economics of such processes. This review paper was aimed to present some information about petroleum solvent and the process in which this solvent is used.