GB826693A - Desulfurization of petroleum oils - Google Patents

Abstract

A process for desulphurizing a petroleum oil containing sulphur comprises subjecting the oil to high-energy ionizing radiation from an atomic pile whereby a substantial proportion of the sulphur is converted to a less stable form and then contacting the liquid oil product with an adsorbent or solvent which selectively removes the less stable sulphur. The oil may boil in the range 80 DEG to 1500 DEG F. and be a virgin stock or the product of conversion processes such as catalytic cracking, hydroforming, steam cracking and coking. It may be naphthenic, paraffinic and/or aromatic. The irradiation may take place in the liquid or vapour phase; 0 DEG to 800 DEG F; under vacuum or up to 100 atmos. pressure; for 1 sec. to 10 days; and use a dosage of 106 to 2 X 1010 roentgens of gamma rays, 1014 to 1019 slow neutrons/cm.2, and 1013 to 1019 fast neutrons/cm.2. The irradiation may also effect conversion of the oil to higher boiling liquid products, lower boiling liquid products, gaseous products and/or solid products. The irradiation time will generally be sufficient to effect such conversion of 5 to 50% wt. of the oil. The irradiation may be effected in the presence of catalytic and non-catalytic particulate solids which may have a particle size of 1 micron to 1 inch, surface areas of 50 to 600 sq. m/g. and pore sizes of 20 to 150 . The solids: oil ratio may be from 2 : 1 to 1 : 10 by volume. Solids mentioned are silicon, metals (e.g. Al, Mg, Ti, V, Pt, Cr, Ni, Fe and Cu), their oxids, and combinations thereof. The metals are preferably chosen so that the product of the fraction of the metal in the solids and its captive cross-section is less than 1 barn. Solids mentioned are silicaalumina, platinum or alumina, and alumina. The solids may be chosen to: (i) promote the conversion of sulphur to volatile forms; (ii) adsorb some of the loosely bound sulphur as it is formed; (iii) control the conversion products; and (iv) control the amount and distribution of radioactive sulphur and phosphorus isotopes formed. The removal of the loosely-bound sulphur may be effected at 30 DEG to 300 DEG F. Desulphurization may be effected with solid adsorbents, e.g. silica-alumina, alumina, silica, bauxite, filter clays, carbon black and ionexchange resins, or with solvents which may be liquids, e.g. water and aqueous solutions of sodium, potassium or ammonium hydroxide or nitric or hydrochloric acid, or gases, e.g. hydrogen, air, oxygen or sulphur dioxide. In examples virgin and cracked gas oils are treated with 2.5 X 1012 neutrons/cm.2/sec. of slow neutrons, 0.5 X 1012 neutrons/cm.2/sec. of fast neutrons and 1.7 X 106 roentgens/hr. of gamma rays in a natural uranium graphite-moderated reactor for 10 days and desulphurized by adsorption with spent silica-alumina catalyst. About 50% conversion (cracking plus polymerization) took place with each oil. Specification 823,426 is referred to.