Absorption method for recovering gas contaminants at high purity
AssigneeUop LLC
InventorsDavid A. Bahr, Lamar A. Davis
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Abstract
Solvent absorption processes for separating components of an impure feed gas are disclosed. The processes involve two stages of gas-liquid contacting, namely a first, absorption stage and a second, stripping stage. In the case of a carbon dioxide (CO2)-containing methane gas as an impure feed gas, contacting, in the stripping stage, the solvent effluent from the absorption stage with a recycled vapor fraction of the solvent effluent from the stripping stage can improve the recovery and purity of not only the methane (and/or other light hydrocarbons in the impure feed gas), but also that of the CO2 contaminant gas.
Claims8
A two-stage gas purification process comprising:
- a) contacting an impure feed gas stream comprising methane and CO2 and a physical solvent stream in a counter-current absorber to provide a first methane-enriched overhead gas stream and a first stage solvent effluent bottoms stream comprising absorbed methane and absorbed CO2;
- b) providing a second stage solvent effluent bottoms stream and contacting the first stage solvent effluent bottoms stream and a recycled vapor fraction of the second stage solvent effluent bottoms stream in a counter-current stripper to provide a second methane-enriched overhead gas stream;
- c) flash separating the second stage solvent effluent bottoms stream in one or more flash separators to provide (i) one or more vapor fractions of the second stage solvent effluent bottoms stream and (ii) a gas-depleted liquid fraction of the second stage solvent effluent bottoms stream;
- and
- d) recovering a purified CO2 product gas stream from the gas-depleted liquid fraction of the second stage solvent effluent bottoms stream.
Dependencies are inferred from the claim text.