HYDROGEN SULFIDE CONTAINING CRUDE OIL TREATMENT PROCESS Russian patent published in 2006 - IPC C10G19/02 C10G29/06 

FIELD: crude oil treatment.

SUBSTANCE: invention relates to methods of treatment of crude oil before subsequent transportation, in particular to treatment of sulfur crude oils and gas condensates with high contents of hydrogen sulfide and mercaptans. Treatment of hydrogen sulfide-containing crude oil is carried out via multistep separation and blow-out with hydrocarbon gas either in low-pressure separation step or in additional desorption column at 25-80°C and pressure 0.1-0.5 MPa until degree of removal of hydrogen sulfide contained in crude achieves 55-90% followed by neutralization of remaining amounts of hydrogen sulfide by adding, at stirring, effective amounts of 20-40% water-alkali solution of sodium nitrite with pH at least 11 or 18-40% aqueous solution of sodium sulfite and sodium bisulfite at sulfite-to-bisulfite molar ratio 1:(0.3-0.9). In this case, sodium nitrite water-alkali solution is added on the basis of 0.9-2.0 mole (preferably 1-1.5 mole) nitrite and aqueous solution of sodium sulfite and bisulfite on the basis of 1-2 mole sulfite and bisulfite per 1 mole residual hydrogen sulfide. When treating hydrogen sulfide and mercaptan-containing crude, the latter is added with 0.9-2 mole (preferably 1-1.5 mole) nitrite per 1 mole residual hydrogen sulfide and light methyl- and ethylmercaptans. Alkali agent in above water-alkali solution of sodium nitrite is sodium hydroxide and/or water-soluble organic amine. Hydrocarbon gas used for the blow-up is preliminarily liberated from hydrogen sulfide separation gas from H₂S-containing crude oil or low-sulfur petroleum gas, or natural gas preferably used on the basis of 2.5 to 10 m³/m³ oil.

EFFECT: increased efficiency of process due to elimination of pollution of commercial petroleum with nitrogen-organic compounds and use of accessible, inexpensive, and less toxic neutralizer, simultaneous neutralization of petroleum acids, reduced acidity and corrosiveness of treated commercial petroleum.

9 cl, 1 dwg, 1 tbl, 8 ex