[1][2] By doing so, the feed gas is made more suitable (less sour) for combustion and/or further processing.
The Selexol process can operate selectively to recover hydrogen sulfide and carbon dioxide as separate streams, so that the hydrogen sulfide can be sent to either a Claus unit for conversion to elemental sulfur or to a wet sulfuric acid process unit for conversion to sulfuric acid while, at the same time, the carbon dioxide can be sequestered or used for enhanced oil recovery.
The Selexol solvent is a mixture of the dimethyl ethers of polyethylene glycol.
Since no chemical reactions are involved, Selexol usually requires less energy than the amine based processes.
However, at feed gas pressures below about 300 psia (2.07 MPa), the Selexol solvent capacity (in amount of acid gas absorbed per volume of solvent) is reduced and the amine based processes will usually be superior.