METHOD OF EXTRACTING LPG Russian patent published in 2020 - IPC C10G5/06 C10G7/02 C07C7/11 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to extraction of liquefied petroleum gas (LPG) during refining combining the use of sponge absorber, ethane distillation column and butanol distillation column. Invention relates to a LPG method from a section of oil refining fractioning, comprising steps of: (a) passing a feed stream comprising a stripping head product, through the sponge absorber and discharge of the off-gas flow from the upper section of the sponge absorber and the stream of light oil fractions from the lower section of the spongy absorber; (b) fractionating the stream of light oil in (i) the head vapor in a stream of desorbed C₃ containing less than 20 % of butane and propane, without condensation and without recirculation of the condensed vapor in the brain fractionation step, (ii) a product LPG stream and (iii) a stream of stabilized naphtha; and mixing a portion of stream of stabilized naphtha of step (b) with effluent gas stream of step (a), followed by condensing gas to obtain absorption oil, which is used in spongy absorber, and separation of flow of sulfur-containing off-gas and condensed water stream. Invention also relates to an apparatus for extracting LPG from a fractionation section of an oil refining process.

EFFECT: technical result is extraction of LPG of at least 90–95 % and with content of hydrogen sulphide (H₂S) in production LPG of not more than 10 weight parts per million.

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