HYDROCARBON GAS PURIFICATION METHOD FROM HS AND CO Russian patent published in 2015 - IPC B01D53/14 B01D53/52 B01D53/62 

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to oil and gas and chemical industries, and namely to purification method of hydrocarbon gas from H₂S and CO₂. The method includes delivery of the purified gas to the absorber under pressure of 5-8 MPa, absorption of acid components by aqueous solution of activated methyl diethanolamine, sequential two-stage weathering of the methyl diethanolamine solution saturated with acid gases at high pressure at the first stage and at low pressure at the second stage, division of the coarse regenerated solution outputted from the second stage into two portions and delivery of a bigger portion to the absorber middle section and delivery of a less portion to a desorber for the purpose of fine thermal regeneration, delivery of the fine regenerated solution outputted from the desorber to the absorber top section. At that the solution outputted from the first stage is delivered to a pump where its pressure in increased per 0.5-1.0 MPa and directed to a waste heat exchanger for heating by the solution outputted from the desorber up to 100-105°C before the second stage of weathering. The fine regenerated solution outputted from the waste heat exchanger is cooled and divided into two portions; the less portion is mixed up with the bigger portion of the solution outputted from the second stage and upon cooling it is delivered to the absorber middle section while the bigger part is delivered to the absorber top section.

EFFECT: invention allows preventing H₂S ingress to the CO₂ absorption zone, reducing energy costs and consumption of expensive solution of methyl diethanolamine.

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