GB582750A - An improved process and apparatus for obtaining glycerine from distillery slops or spent wash - Google Patents

Abstract

<PICT:0582750/III/1> Glycerine is obtained from distillery slops or waste by a process which is characterised by the feature that the slops, after being heated under pressure to a temperature above the boiling point of the slops at atmospheric pressure are united in the bottom part of an evacuated still with a slops distillation residue heated at least to the distillation temperature of crude glycerine to distil off the glycerine content of the slops by the thermal action of the residue. The crude glycerine which is distilled off is freed from organic impurities before being further worked up. The union p of fresh slops and distillation residue may be effected either by sucking the freshly supplied slops into the distillation residue and mixing them up with it or by introducing the slops in a fine state of sub-division into the preferably evacuated still on to the surface of the distillation residue contained therein so that the sprayed drops penetrate into the distillation residue. The distillation of the glycerine is effected by the application of heated steam. The crude residue may be either intermittently or continuously withdrawn from the still. Before the crude glycerine is further worked up it is heated to a temperature between its boiling point and the boiling point of water and the alkalinity is continuously controlled by the continuous addition of an alkaline agent. In an example distillery slops neutralised with lime are evaporated in vessel 1 and heated to about 90 DEG C, compressed by pump 2 and forced through preheater 3 through pipe 4 to the lower part of the still 6. The charge is heated to expel water and organic matters. When the temperature has risen to 140 DEG -150 DEG C. the crude glycerine is distilled off by introducing steam from a superheater 19 through a pipe 20. Half the residue is withdrawn into a receptacle 8 through aperture 7, and the charge in the still made up by introducing fresh slops. The slops may alternatively be introduced through a pipe 12 and pressure reducing valve 5 by a sprinkler 13. The introduction may be either intermittent or continuous. In the former case it is possible to separate the glycerine from the other volatile constituents and in the latter case a subsequent separation is necessary. The crude glycerine obtained from the coil 11 is heated to above 100 DEG C. and then worked up by treatment with alkali (milk of lime, or soda lye) and distillation.