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524,541. Distilling tar acids. CRAIG & CO., Ltd., A. F., and MURRAY, W. F. Feb. 1, 1939, No. 3371. [Class 32] Tar acids, after continuous dehydration, are pumped through a heater and passed, e.g. at 160‹ C. into a vaporizer operating under reduced pressure, e.g. 80 mm. of mercury, to liberate, as vapours, substantially all phenol, cresols and xylols and leave a residue of pitch and high boiling acids, the liberated vapours being then passed to a fractionating column operating under reduced pressure in such a manner that xylenols are recovered as a residue and meta an d para cresols as a side stream while phenol and orthocresol are removed as an overhead which is condensed and passed through a second heater to a second fractionating column where orthocresol containing a small percentage of phenol is recovered as a residue and pure phenol is recovered as an overhead. As shown, tar acids are passed through heat exchanger 2 and steam heater 2a to a dehydrator 3 from which the dehydrated crude passes through cooler 7 to-a storage vessel 8. From the vessel 8 the crude is pumped through a heater 11 and passed, e.g., at a temperature of 160‹ C. to a vaporizer 12 operating under reduced pressure, e.g. 80 mm. of mercury. Residue is withdrawn to a vessel 21 and the vapours pass to a fractionator comprising two bubble columns 13, 14 equipped with reboilers 15, 16 and reflux condensers 17, 18. Meta-4-xylenol is withdrawn from the base of column 13 and meta- and para-cresols from the base of column 14 to receivers 22, 23 respectively. Vapour passes to a condenser 19 and thence to a storage vessel 24 from which it is passed through heater 25 to a second fractionator comprising two columns 26, 27, orthocresol being withdrawn from the base of column 26 to a receiver 32 and the liquid from the base of column 27 being returned to column 26. Phenol vapours are condensed at 30 and passed to a receiver 33.
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