Fluid bed process for para-xylene production

A process for the selective production of para-xylene which comprises:

• (a) providing, in a fluidized bed, a fluidizable catalyst comprising a microporous material having a Constraint index of from about 1 to about 12, the microporous material containing phosphorous and having undergone prior treatment with a steam-containing atmosphere at a temperature between about 250.degree. C. to about 1050.degree. C. for between about 10 minutes and about 100 hours;
• (b) controlling the relative concentration of catalyst particles having a major dimension of less than 40 microns at between about 5 and 35 weight percent, said catalyst particles having an apparent particle density of about 0.9 to 1.6 grams per cubic centimeter and a size range of about 1 to 150 microns, and an average catalyst particle size of about 20 to 100 microns;
• (c) charging toluene and a methylating agent selected from methanol, methylchloride, methylbromide, dimethylether and dimethylsulfide to said fluidized bed at a rate sufficient to maintain said fluidized bed in a turbulent sub-transport flow regime;
• and
• (d) reacting said toluene with said methylating agent and recovering xylenes containing more than 90 wt % para-xylene from said fluidized bed.