Patent ID: 7084318

Claim:
A method of preparing a xylene product comprising: providing a reactor containing a phosphorus-treated ZSM-5-type zeolite catalyst; initiating start-up of a toluene methylation reaction by contacting the catalyst with a toluene/methanol feed and a cofeed of hydrogen introduced into the reactor at start-up conditions wherein the toluene/methanol feed is introduced into the reactor at a liquid hourly space velocity (LHSV) of more than 5 hr −1 and the cofeed of hydrogen is introduced at a hydrogen/(toluene+methanol) molar ratio of less than about 8; operating the reactor at the start-up conditions for about one-half to about 20 hours; and then operating the reactor at run conditions wherein the LHSV is reduced by at least 5 hr −1 or more from the start-up LHSV to to a run LHSV of 10 hr −1 or less and the hydrogen/(toluene+methanol) molar ratio is at least 1.0.