Patent ID: 7259283

Claim:
A process for the production of ethyl benzene over a zeolite beta alkylation catalyst and the regeneration of said catalyst comprising: (a) providing an alkylation reaction zone incorporating a catalyst bed of a zeolite beta alkylation catalyst; (b) supplying an aromatic feed stock containing benzene into said catalyst bed at an inlet side of said reaction zone; (c) supplying ethylene to the inlet side of said reaction zone and into contact with said catalyst bed; (d) operating said alkylation reaction zone at temperature and pressure conditions in which benzene is in the gas phase, the liquid phase or the supercritical phase to cause ethylation of said benzene by an exothermic reaction in the presence of said zeolite beta alkylation catalyst with the production of an exotherm which passes through said catalyst bed in a direction from the inlet of said reaction zone to the outlet of said reaction zone; (e) continuing the supply of said aromatic substrate and ethylene to said reaction zone until said exotherm traverses a substantial portion of the catalyst bed; (f) thereafter terminating the supply of ethylene and benzene to said reaction zone; and introducing an inert gas into said reaction zone to provide temperature conditions in said reactor which initially are lower than the temperature conditions of subparagraph (d); (g) increasing the temperature in said reaction zone and initiating the supply of an oxidative regeneration gas comprising a mixture of oxygen and said inert gas through said catalyst bed to oxidize said coke and produce an exotherm which moves through said catalyst bed; (h) continuing the passage of said regeneration gas through said catalyst bed to result in decoking of said zeolite catalyst within said bed until the exotherm passes through a substantial portion of the bed; (i) thereafter supplying a regeneration gas comprising a mixture of oxygen and inert gas having an increased ratio of oxygen to the inert gas to oxidize said coke at an increased temperature greater than the temperature in subparagraph (g); and (j) thereafter further diminishing the oxygen content of said regeneration gas and passing on inert gas through said catalyst bed at a reduced temperature.