| 摘要 |
Non-equilibrium C1- 3 alkyl substituted aromatic hydrocarbons feeds are equilibrated (by isomerization and/or transalkylation and/or disproportionation) by contact in the vapour phase at 600-1000 DEG F., at a pressure below 200 atmospheres, and at a liquid hourly space velocity less than 10, with a solid acidic mixed metal oxide catalyst having equilibration and coke-forming activities, the process being carried out in the presence of at least 10 parts of added ammonia per million parts of aromatic hydrocarbon feed so as to inhibit coke formation. Water vapour may also be present. Numerous suitable catalysts are mentioned including acid-treated clays, natural and synthetic zeolites, and decationized molecular sieves, silica/alumina being used in the examples. Aromic feeds mentioned include non-equilibrium mixtures, and many single isomerizable alkylbenzenes, the examples relating to treatment of a xylene mixture containing a reduced p-xylene content. The feeds may be pretreated to remove light volatile impurities by passage in the liquid phase through a molecular sieve absorption bed.
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