US Patent 7629498 Process of manufacturing para-xylene

This disclosure relates to a process of manufacturing para-xylene, comprising (a) contacting a pygas feedstock and methylating agent with a catalyst under reaction conditions to produce a product having para-xylene, wherein the product has higher para-xylene content than the para-xylene content of the pygas feedstock; and (b) separating the para-xylene from the product of the step (a), wherein the catalyst comprises a molecular sieve having a Diffusion Parameter for 2,2-dimethylbutane of about 0.1-15 sec−1 when measured at a temperature of 120° C. and a 2,2-dimethylbutane pressure of 8 kPa-a and the pygas comprises from about 1 to about 65 wt % benzene and from about 5 to 35 wt % toluene.