GB830923A - Improvements in and relating to the refining of crude petroleum oil - Google Patents

Abstract

A process for refining crude mineral oils of high asphalt and sulphur content particularly for producing high quality fuel oil shaving low viscosity and low content of asphalt, ash and sulphur, comprises passing the crude mineral oil, as such, or deprived of the light fractions boiling at temperatures under 392 DEG F. at a temperature above 600 DEG F. and at a pressure above 70 p.s.i.g. into a contact chamber, together with hydrogen or hydrogen-containing gases, in the presence of a contact mass of high porosity, having a high surface area, this mass being characterized by a pore volume of at least 40% of the total volume and a surface area greater than 80 sq. metres per gram, but not containing in substantial quantities any metal or metallic compound having specific hydrogenating or desulphurizing characteristics, the space velocity being between 0.5 and 5.0 volumes of liquid per hour per volume of contact mass, and the ratio between hydrogen or hydrogen containing gas and the liquid feedstock in the contact chamber being maintained between 3.2 and 6 standard cubic feet per pound of feedstock the operating conditions of temperature, pressure, space velocity, of oil feed and ratio of proportions of hydrogen or hydrogen-containing gas and liquid feedstock in the contact zone being chosen, according to the nature of the crude mineral oil to be processed so as to avoid any substantial cracking or consumption of hydrogen and to promote the decomposition of the organic-metallic complexes prsent in the oil, the coagulation of the asphaltenes present in the oil and the partial decomposition of the high-boiling point organic sulphur compounds present in the oil, and separating the coagulated asphaltic material, together with the precipitated mineral matter from the treated oil. In an example, preheated crude oil from the Middle East is passed to a reaction zone containing activated carbon with a space velocity of 1-1.5 liquid volumes/hour/volume of the contact mass at a temperature of 785-825 DEG F. and at a pressure of 425-500 p.s.i.g. in the presence of hydrogen and recirculating the hydrogen at a rate of 8-16 cu. ft. per pound of feedstock. The resulting liquid phase is fractionated and further treated with a conventional cobaltmolybdate catalyst to reduce the sulphur content.