Abstract: A liquid containing a contaminant such as water or polymeric solids is purified. Purification of a liquid containing a contaminant is enhanced by the use of second fractionating column in conjunction with a first fractionating column to recover a portion of the liquid to be purified from the kettle product of the first column. Vapor from a second fractionating column is used to control the total energy input to a first fractionating column.

Abstract: A recovery and purification operation in which a perfluorocarboxylic acid fluoride, e.g., trifluoroacetylfluoride, is recovered having a high purity from an electrochemical cell fluorination operation is described. The effluent is compressed and chilled, separation of vapor from liquid phases is effected to produce a liquid which is further chilled and subcooled and employed as absorption medium in an absorption zone. Vapors separated are compressed and chilled and subjected to a further phase separation, vapors from which are passed to the absorption zone. The enriched absorption medium together with liquid from the second phase separation is passed to a fractionation zone for recovery of the perfluorocarboxylic acid fluoride from incompletely fluorinated compounds which can be returned to the cell for further fluorination.The invention is applicable to the recovery of perfluorocarboxylic acid fluorides of mono- and dicarboxylic acids containing from 2 to about 10 carbon atoms.

Abstract: Antifreeze agents such as methanol used in treating hydrocarbon-containing streams to prevent the formation of hydrates and ice are recovered in a combination process comprising extraction, fractionation, and stripping together with a common reboiler system for the fractionation and stripping. One process comprises a combination of solvent extracting methanol with water, fractionation of the water-methanol extract to separate methanol overhead, further treatment of the fractionation bottoms by stripping to remove residual methanol overhead which is returned to the fractionation zone, and recycling at least a portion of the fractionation bottoms as solvent to the initial extraction step.