Process for the removal of gas contaminants from a product gas using polyethylene glycols
AssigneeUnion Carbide Chemicals & Plastics Technology Corporation
InventorsCraig Norman Schubert, William I. Echt
Life of this patent
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Abstract
The present invention provides a process for removing gas contaminants such as hydrogen sulfide and carbon dioxide from a product gas such as natural gas or synthesis gas. According to the invention the product gas is contacted with a solvent which includes dialkyl ethers of polyethylene glycols and water, and a high pressure recycle loop is utilized to desorb a portion the gas contaminants and co-absorbed product gas from the solvent. The solvent is provided with an amount of water sufficient to increase recovery of co-absorbed product gas while at the same time providing a reduced circulation rate requirement for the solvent and reduced re-compression and cooling requirements for the recycle gas.
Claims7
A process for removing gas contaminants from a product gas containing such contaminants, said process comprising the steps of:
- (a) contacting the product gas with a solvent comprising a mixture of dialkyl ethers of polyethylene glycols in at least one absorption stage to remove a specified portion of the gas contaminants from the product gas;
- (b) discharging the product gas having the specified portion of the gas contaminants removed therefrom from the absorption stage;
- (c) passing the solvent containing dissolved gas contaminants and co-absorbed product gas to a high pressure recycle loop to partially regenerate the solvent by releasing a portion of the dissolved gas contaminants and the co-absorbed product gas from the solvent as a recycle gas;
- (d) re-compressing and cooling the recycle gas and then returning the recycle gas to the absorption stage;
- (e) completing regeneration of the solvent by removing from the solvent a residual portion of the gas contaminants and the co-absorbed product gas remaining therein and releasing the residual portion as a discharge gas;
- (f) returning the completely regenerated solvent to the absorption stage;
- and
- (g) providing the solvent with an amount of water sufficient to increase recovery of co-absorbed product gas while at the same time providing a reduced circulation rate requirement for the solvent and reduced re-compression and cooling requirements for the recycle gas.
Dependencies are inferred from the claim text.