Methylation of toluene to para-xylene
AssigneeExxon Chemical Patents Inc.
InventorsGary D. Mohr, Robert Scott Smith
Life of this patent
Estimating the term…
Abstract
A process is provided for the production of paraxylene by the methylation of toluene in the presence of a zeolite bound zeolite catalyst. The catalyst comprises first zeolite crystals which are bound together by second zeolite crystals. When used to methylate toluene to para-xylene, the zeolite bound zeolite catalyst has a para-xylene selectivity greater than thermodynamic equilibrium. This selectivity can be enhanced by selectivating the catalyst.
Claims26
A process for making para-xylene by reacting toluene with a methylating agent under methylation conditions in the presence of a zeolite bound zeolite catalyst which does not contain significant amounts of non-zeolitic binder and comprises:
- (a) first crystals of a first intermediate pore size zeolite;
- and
- (b) a binder comprising second crystals of a second zeolite.
A process for the selective production of para-xylene which comprises reacting toluene with methanol under methylation conditions in the presence of a catalyst which does not contain significant amounts of non-zeolitic binder and comprises first crystals of ZSM-5 and a binder comprising second crystals of a zeolite selected from the group consisting of ZSM-5, ZSM-11, Silicalite 1, and Silicalite 2.
Dependencies are inferred from the claim text.