GB982514A - Recovery of resorcinol - Google Patents

Abstract

Resorcinol is recovered from the product of acid cleavage of m-diisopropylbenzenedihydroperoxide by distilling the cleavage product to remove low-boiling materials, heating the resulting product containing resorcinol to vaporize substantially all of the products other than the high-boiling condensation products, cracking the residual liquid mixture under reduced pressure and with the aid of steam stripping to vaporize further quantities of resorcinol, condensing the combined products of the vaporizer and the cracking process, and recovering resorcinol therefrom. The vaporization may be effected at a temperature in the range from 200 DEG to 250 DEG C., while the cracking may be effected in the range from 200 DEG to 280 DEG C., preferably at less than 500 mm. Hg, and particularly in the range from 50 to 250 DEG mm. Hg. Preferably the feed to the cracker is maintained above pH3 and the vapour phase before condensation is in the pH range from 4 to 7. In an example, a product obtained by the distillation of the cleavage product to remove low-boiling constituents is fed through <PICT:0982514/C2/1> 1 to vaporizer 2 in which all the uncombined resorcinol and water are vaporized; the vapour and residue is fed to column 4, the vapour passing overhead via 8 and the liquid residue to cracker 5 where it is thermally cracked while steam enters at 6 to drive off the vapours, and tar is removed at 7; the combined vapours from column 4 pass into condenser 9 and are cooled directly by water sprayed through 10; liquid resorcinol flows via 11 to vacuum receiver 12 into which flows water obtained by condensing in 14 any vaporized cooling water; toluene is added at 17 to remove phenolic substances and the mixture is taken off via 18 for separation of the resorcinol phase.