Extraction Separation of Sulfur Compounds From Crude Oils in a Flow-Through Mode

A flow-through method is proposed for the separation of sulfur compounds from sulfur and sour crude oils by solvent extraction using centrifugal extractors. The effectiveness of using various organic (tetrahydrofuran, pyridine, methanol, ethanol, acetone, dimethylformamide, and acetonitrile) and inorganic (mineral acids, NaOH) extractants for the extraction of sulfur-containing compounds from crude oils of the Ashal’chinskii and Romashkinskii deposits is estimated. It is shown that methanol and dimethylformamide are most effective for extracting sulfur from crude oils. The use of additional sample preparation, which consists in the ultrasonic and/or magnetic processing of oil in combination with its oxidation and heating, increases the efficiency of extraction of sulfur-containing compounds by 20–40%. It is shown that the choice of extractant composition for the extraction of sulfur compounds is determined by the physicochemical properties and composition of the oil.