Removing salt from glycolic acid soln. - by heating in presence of immiscible solvent to remove water, then filtering

摘要

Removal of NaCl from aq. glycolic acid (I) soln. comprises mixing the soln. with 0.5-10 times its wt of a solvent (II) which is insoluble or very sparingly soluble in water. (II) has b.pt above that of water, or that of the water-(II) azeotrope. The mixt. is then heated at between the b.pt of water (or azeotrope) and the b.pt of (II) until practically all the water is removed. The pptd. NaCl is then removed and finally (I) freed of (II). Specified (II) are diethyl ketone, MlBK and dibutyl ether. (I) is used in textile, leather and fur processing; in metal cleaning and plating; in disinfection of dairy equipment, and to inhibit scale formation in heat exchangers. Practically quantitative removal of (corrosive) NaCl is achieved simply.