PROCESS FOR PRODUCTION OF LOW SULFUR-CONTENT DISTILLATES FROM LIQUID HYDROCARBON FEEDSTOCK Russian patent published in 2004 - IPC

FIELD: petroleum processing.

SUBSTANCE: invention relates to production of fuel fractions from liquid hydrocarbon feedstock and to oxidative purification of these fractions to remove sulfur compounds. Process is carried out by oxidizing feedstock with nitric acid or nitric acid/hydrogen peroxide mixture at 40-140^оС and pressure up to 1 MPa, after which aqueous layer is separated from hydrocarbon layer, low-molecular oxidation products are extracted from hydrocarbon feedstock by polar solvents and feedstock fractioned. In the latter operation, high-molecular oxidation products remain in still residue (mazut). For 1 mole sulfur, 0.6 to 2 mole nitric acid is used with concentration 35-99.5% and content of 0.05 to 2.0% nitrogen oxide calculated as NO₂. Mixture HNO₃/H₂O₂ is taken such as to provide 0.3 to 1.5 mole active oxygen per 1 mole sulfur. Polar extractants are selected from sodium hydroxide, carbonate, and sulfate aqueous solutions, glycols, ethanolamines, dimethylformamide, cellosolves, acetone, isopropyl alcohol, and mixtures thereof. Petroleum-origin sulfoxides and sulfones are separated from extract using known techniques.

EFFECT: enhanced process efficiency.

7 cl, 1 dwg, 4 tbl, 5 ex