GB244775A - Treatment of gas liquors for removing phenolic impurities therefrom - Google Patents

Abstract

244,775. Heffner, L. W., and Tiddy, W. Dec. 16,1924, [Convention date]. Ammonia, distilling.-In preparing ammonium sulphate or concentrated ammonia from gas liquor, the liquor is treated for the recovery of phenol and to obtain a waste liquor free from phenol by maintaining the upper end of the free ammonia still at a temperature of 98-103‹ C. or over. The stream of ammonia gas carries over the phenol as ammonium phenolate. Additional ammonia may be added to the stream or part of the ammonia freed from phenol may be recirculated. The liquor preheated to 98‹ C. in a steam heater 1 passes by a pipe 3 into the top of a free ammonia still 6 which surmounts a liming chamber 8 connected to a fixed ammonia still, the vapours from which pass by a pipe 11 into the base of the still 6. The vapour outlet 7 leads either to a sulphuric acid saturator, in which case phenol may be separated from the gases leaving the saturator, or to a phenol absorber containing caustic soda solution. Part of the water vapour may be first separated by passage through a reflux condenser 7<c> which cools the vapours to 98‹ C. A countercurrent scrubber may be interposed bertween the preheater 1 and the top of the still 6, or between the still 6 and the liming chamber, and the vapours may pass through a phenol absorber before passing into the scrubber. The ammonia vapours after separation of phenol may be partially cooled to separate water and passed through an oil serubber and through a charcoal and a bone black filter before being absorbed in distilled water. Specificabian 244,774 is referred to.