GB823297A - Process for the separation of mixtures of liquids - Google Patents

Abstract

<PICT:0823297/III/1> <PICT:0823297/III/2> Mixtures of liquids are at least partially separated by a process comprising partial vaporization of the liquid mixture and/or partial condensation of the vaporized mixture in the presence of granular or porous sintered substances, such as quartz sand, sintered glass or granular basalt, which are warmer than the mixture, and whose infra-red vibration absorption bands overlap those of only one of the components of the mixture, so that this particular component is vaporized to a greater extent in the vaporization step and is condensed to a smaller extent in the condensation step than would be the case in the absence of the large surface solid body. In Example (1), water containing 1 part in 7000 of deuterium oxide D2O is introduced at a temperature of 18 DEG C. through tube A (Fig. 1), at the rate of 10 ml. per minute; and it flows through a porous plate E, which is 1 cm. thick, made of sintered glass, the void diameter being 0.01 to 0.03 mm. The temperature of the apparatus is 20 DEG C. At the same time, air at 20 DEG C. is introduced through tube B at the rate of 2.1 litres per minute. The air, laden with water-vapour, withdrawn through tube C is cooled; and the condensate is found to contain 1.1% of D2O. Alternatively, the vapour-air mixture from tube C is passed up through metal tube G (Fig. 2), which is charged with basalt grains 0.1 to 1.0 mm. in diameter, and is heated to 95 DEG C. by means of jacket H. The vapour-air mixture leaving tube F contains practically only H2O in the first 100 minutes of the run; while the water condensed on the basalt grains in tube G contains all the D2O. Carbon dioxide gas is then passed through tube G at about 110 DEG C., and the H2O/D2O mixture is vaporized from the grains. The liquid, condensed from the gas outside the tube, consists of approximately one quarter of D2O. In Example (2), dioxane-water mixture of azeotropic composition (i.e. 80% dioxane) is passed at 45 DEG C. and at 30 ml. per min. through a 1 cm. layer of quartz sand at 60 DEG C., together with 2.1 litres per minute of nitrogen at 45 DEG C. The effluent gas/vapour mixture is passed for 30 seconds into a cooling trap, and afterwards into a different cooling trap. Analysis of the two condensates and of the non-vaporized liquid shows that there has been preferential vaporization of dioxane from the azeotropic mixture.