Regeneration of zeolite catalysts - used for toluene disproportionation or transalkylation

摘要

Process for regenerating zeolite-based catalysts used for the disproportionation of toluene or the transalkylation of toluene with C9 or C10+ polymethylbenzenes, is claimed. Process comprises slowly burning off the coke deposit while continuously or discontinuously increasing the temp. with the modification that either (a) regeneration is effected in the presence of steam or (b) regeneration is preceded or followed by treatment with steam. In either case, the temp. is 200-750 degrees C (pref. 300-600 degrees C and the gas phase contains 0.5-100 pref. 3-100) vol.% H2O. Process gives better results than simple regeneration in a dry atmos. The regenerated catalyst has the same activity as fresh catalyst and its selectivity is increased.