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OwnerHeliodoro Monroyinventor
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A process of recovering BHT values from the mother liquors of the crystallization of BHT obtained by alkylating p-cresol with isobutylene in the presence of a catalyst and crystallizing the BHT, comprises thermally cracking the starting mother liquor at a temperature of from 200.degree.C to 250.degree.C in the presence of an acid catalyst to reform the cresol polymers, steam distilling the cracked mixture to increase the p-cresol content and remove the diisobutylene, realkylating the steam-distilled reaction mixture with additional isobutylene, to produce a crystallizable mixture of BHT having a BHT concentration of from 80 to 85% by weight, and recovering the BHT by crystallization. The mother liquors remaining after realkylation and crystallization can be admixed with the starting mother liquors and reused in the thermal cracking step of the process.
A process for the recovery of 2,6di-tert-butyl-p-cresol from a starting non-crystallizable mother liquor obtained from the crystallization of 2,6-di-tert-butyl-p-cresol produced by the alkylation of p-cresol with isobutylene, said starting non-crystallizable mother liquor comprising diisobutylene and lower and higher cresol polymers which inhibit crystallization of 2,6-di-tert-butyl-p-cresol, which comprises the steps of:
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