Solventless Deasphalting: Selective Sulfonation Chemistry of Petroleum Asphaltenes and Resids

Abstract

Asphaltenes are the lowest value component of petroleum. They are found in a variety of crude oils and in higher concentrations in resids and bitumens. Petroleum resid is the non-volatile fraction of crude oil or bitumen after distillation. Current disposition of the asphaltenes is high-temperature thermal chemistry to form higher value liquids and coke or as feedstock for asphalt. Asphaltenes are separated from a resid by a commercial process called solvent deasphalting. Deasphalting is accomplished by treating a resid with a hydrocarbon solvent (propane or butane commercially and pentane−heptane in the lab), and the asphaltenes precipitate out of solution. The rest of the resid is soluble, and this is called the deasphalted oil (DAO). The DAO is recovered by evaporation of the solvent. The DAO is higher value than the original resid, and it is used as residual sulfur fuel oil (RSFO) and, in some cases, as a feedstock for fluid catalytic cracking (FCC) to form higher value liquids. Asphaltenes are compos...