Removal of sulfur compounds from glycolic and alcoholic compounds by solvent extraction

Claim 2

The process of claim 1, wherein the extracting solvent comprises 0.15 to 0.40 part by weight of said water-immiscible hydrocarbon and 0.5 to 1.0 part by weight of said water.

Claim 3

The process of claim 1, wherein the water-immiscible hydrocarbon is selected from the group consisting of trichloroethylene, benzene, toluene, furan, monochlorobenzene, or mixtures thereof.

Claim 4

The process of claim 1, wherein said glycol compound is a dialkyl ether of a polyalkylene glycol or mixtures thereof.

Claim 5

A process for removing hydrogen sulfide from a gaseous mixture containing hydrogen sulfide and for removing sulfur compounds selected from the group consisting of organic polysulfides, hydrogen polysulfides, elemental sulfur, alkyl disulfides, mercaptans and mixtures thereof from sulfur-bearing solutions comprising normally liquid dialkyl ethers of polyalkylene glycols as a principal component, said process comprising the steps of: a. contacting said gaseous mixture in a first zone with 0.1 to 3.0 pounds of liquid solvent per standard cubic foot of gas to be absorbed, the liquid solvent comprising dialkyl ethers of polyalkylene glycols, to effect absorption of substantially all of the hydrogen sulfide and a minor portion of other gases; b. passing the liquid solvent containing the absorbed hydrogen sulfide to a second zone maintained at a pressure substantially lower than that in the first zone to effect liberation of the other gases; c. withdrawing from said second zone the gases liberated therein; d. withdrawing said solvent from said second zone; e. passing an oxygen-containing gas in contact with said solvent containing hydrogen sulfide in a stripping zone which is maintained under conditions such that the glycol will be at least 100* F. when it reaches the base of said stripping zone, to effect removal of substantially all of the hydrogen sulfide therefrom; f. withdrawing said glycol solvent from said stripping zone; g. contacting in a third zone one part of said stripping zone solvent comprising said dialkyl ethers of polyalkylene glycols and said sulfur compounds with an extracting solvent consisting of 0.05 to 1.0 part for each part by weight of said stripping zone solvent of a water-immiscible liquid hydrocarbon compound having a boiling temperature in the cyclic range 50* F. to 500* F. and a relatively high miscibility with said sulfur compoundS, wherein said water-immiscible hydrocarbon is selected from the group consisting of chlorinated saturated and/or unsaturated hydrocarbons, aromatic hydrocarbons, chlorinated aromatic hydrocarbons, unsaturated oxygen-containing cyclic hydrocarbons, and mixtures thereof, and 0.1 to 2.0 parts of water for each part by weight of said stripping zone solvent; h. mixing said stripping zone solvent with said extracting solvent; i. separating a liquid phase comprising said dialkyl ethers of polyethylene glycols and water from a liquid phase comprising said water-immiscible carbon compound and said sulfur compounds; j. dissociating said dialkyl ethers of polyethylene glycols from said water; k. withdrawing said glycol from said third zone; and l. returning said glycol to the top of said first zone for further contact with the gaseous mixture.

Claim 6

The process of claim 6, wherein steps (g) through (k) serve as a sidestream to said process, which sidestream is a solvent extraction process for removing said sulfur compounds from a solution comprising said glycol and said sulfur compounds.

Claim 7

In a process for removing hydrogen sulfide from a gaseous mixture containing hydrogen sulfide, which process comprises the steps of: a. contacting said gaseous mixture in a first zone with 0.1 to 3.0 pounds of liquid solvent per standard cubic foot of gas to be absorbed, the liquid solvent comprising dialkyl ethers of polyalkylene glycols, to effect absorption of substantially all of the hydrogen sulfide and a minor portion of other gases; b. passing the liquid solvent containing the absorbed hydrogen sulfide to a second zone maintained at a pressure substantially lower than that in the first zone to effect liberation of the other gases; c. withdrawing from said second zone the gases liberated therein; d. withdrawing said solvent from said second zone; e. contacting said solvent with an oxygen-containing gas in a stripping zone which is maintained under conditions such that said solvent will be at least 100* F. when it reaches the base of said stripping zone, to effect removal of substantially all of the hydrogen sulfide therefrom; and f. returning said solvent essentially free of hydrogen sulfide to the top of said first zone for further contact with the gaseous mixture; the improvement comprising the use of a solvent extraction process as a sidestream for the removal of sulfur compounds selected from the group consisting of organic polysulfides, hydrogen polysulfides, elemental sulfur, alkyl disulfides, mercaptans and mixtures thereof from said solvent, extraction process comprises the steps of (1) contacting said solvent containing sulfur compounds, with 0.05 to 1.0 part for each part by weight of said solvent of an extracting solvent comprising a water-immiscible liquid hydrocarbon compound having a boiling temperature in the range 50* F. to 500* F. and a relatively high miscibility with said sulfur compounds, wherein said water-immiscible hydrocarbon is selected from the group consisting of chlorinated saturated, and/or unsaturated hydrocarbons, unsaturated oxygen-containing cyclic hydrocarbons, and mixtures thereof, and 0.1 to 2.0 parts of water for each part by weight of said solvent; (2) mixing said solvent with said extracting solvent; and (3) separating a liquid phase comprising said solvent and water from a liquid phase comprising said water-immiscible hydrocarbon and said sulfur compounds.

Claim 8

The process of claim 8, wherein said improvement is added as a sidestream between said step (d) and said step (e).

Claim 9

The process of claim 8, wherein said improvement is added as a sidestream between said step (e) and said step (f).