Inventors:
George S. Somekh - New Rochelle NY
Assignee:
Union Carbide Corporation - New York NY
International Classification:
C07D20116
Abstract:
A solvent extraction-distillation process for the recovery of a water-soluble aliphatic amide having 1 to 8 carbon atoms or mixtures thereof from an aqueous solution wherein the concentration of the amide is in the range of about 0. 25 percent by weight to about 25 percent by weight, based on the weight of the solution, and the solvent is a compound having the following structural formula: ##STR1## wherein M is OH or CH. sub. 2 OH, R is hydrogen or an alkyl radical, there being at least one alkyl radical, and the total number of carbon atoms in all of said alkyl radicals taken together is 3 to 12, or a mixture of isomers thereof, Said compound or mixture of isomers having a boiling point higher than the amide and less than about 350. degree. C. and being non-azeotropic with the amide, Comprising the following steps: (a) contacting the solution in an extraction zone with the solvent to provide an extract comprising solvent, amide, and no more than about 5 percent by weight of water based on the weight of the solution and a raffinate comprising at least about 95 percent by weight of water based on the weight of the solution and less than about 5 percent by weight of solvent based on the weight of the solvent; (b) introducing the extract from step (a) into a distillation zone wherein the pressure is less than about 500 millimeters of mercury and the temperature is less than the decomposition temperatures of the amide and the solvent at said pressure, to separate the solvent from a mixture of amide and water; and (c) recovering the mixture of amide and water.