Separation of chlorosilanes by extractive distillation
AssigneeDow Corning Corporation
InventorsOra L. Flaningam, Roland L. Halm
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Abstract
A method for separating close-boiling chlorosilanes by the procedures of extractive distillation using sulfolane as the extractive solvent is described. An example of close-boiling chlorosilanes which can be separated by this method include dimethyldichlorosilane and methyltrichlorosilane containing mixtures. The invention comprises heating a mixture of the close-boiling chlorosilanes with sulfolane to distill the lower-boiling chlorosilane from the mixture and thereafter separating the sulfolane and the high-boiling chlorosilane.
Claims6
A method of separating close-boiling chlorosilanes which comprises removal, by extractive distillation, of the lower-boiling chlorosilane from the close-boiling chlorosilanes by heating a mixture of the close-boiling chlorosilanes with sulfolane to extractively distill the lower-boiling chlorosilane from the mixture and thereafter separating the sulfolane and the higher-boiling chlorosilane.
A method of separating close-boiling chlorosilanes which comprises removal, by extractive distillation, of the lower-boiling chlorosilane from the close-boiling chlorosilane by contacting the mixed vapors of the close-boiling chlorosilanes with sulfolane at a temperature above the boiling point of the lower-boiling chlorosilane whereby the lower-boiling chlorosilane is extractively distilled and removed preferentially from the contact zone and thereafter separating the sulfolane and the higher-boiling chlorosilane.
A method of separating close-boiling chlorosilanes which comprises removal, by extractive distillation, of the lower-boiling chlorosilane from the close-boiling chlorosilane by passing the mixed vapors of the close-boiling chlorosilanes through a vessel and countercurrently passing liquid sulfolane, at a temperature greater than the boiling point of the lower-boiling chlorosilane, through the vessel in intimate contact with the mixed vapors of the close-boiling chlorosilane whereby the low-boiling chlorosilane is extractively distilled and substantially removed from the vessel in vapor form and thereafter separating the sulfolane and the higher-boiling chlorosilane.
Dependencies are inferred from the claim text.