GB300964A - - Google Patents

Abstract

300,964. Still, C. Nov. 21, 1927, [Convention date]. Addition to 293,702. Materials and compositions for purifying.- The light oil obtained as a liquid distillate in distilling wash oil containing benzene &c., as described in the parent Specification, is rectified in a separate distilling apparatus and the resulting naphthalene - charged rectification residue is returned while still warm to the distilled wash oil passing into new circulation. The cooled distillation gases containing benzene are admitted through a pipe 1 in the usual manner into the bottom of a scrubbing tower 2 and are led away free from benzene through a pipe 3. The filling of the tower 2 is sprinkled with debenzolized wash oil from a tank 6 and the oil charged with benzene is stored in a tank 8 from which it is drawn by a pump 9 to the distilling plant. The latter comprises a heater 10. a column 13 in which the heated oil is freed from benzene &c. and also partially from naphthalene by the direct action of steam, and a condenser 15 in the lower part of which the light oil and water separate out. The water is discharged through a pipe 16 and the light oil passes into a rectifying column 18. The lower part of this column is heated indirectly by steam from a pipe 19 and a reflux condenser 20 is mounted on the top, provision being also made for direct steam heating. A product containing 95-98 per cent benzene distils over and is condensed in the condenser 22, any residual water being removed through a pipe 23. The residue collecting at the bottom of the column 18 comprising mainly oils boiling above 180‹C. and naphthalene, is delivered to a tank 26 and pumped through a pipe 28 into the top of the column 2, where any benzene residues are recovered.