| 摘要 |
1474065 p-Xylene INSTITUT FRANCAIS DU PETROLE 19 Sept 1974 [27 Sept 1973] 40907/74 Heading C5E p-Xylene is produced by reacting toluene with an aromatic compound having an aromatic nucleus substituted by at least four methyl groups, under transalkylation conditions, in the vapour or liquid phase, and at a temperature in the range 50-450‹ C. and a pressure in the range 1-150 bars (absolute), and a spatial feed velocity in the range 0À05-10 by weight of feed charge per unit weight of catalyst, per hour, in the presence of a transalkylation catalyst which comprises an acid zeolite having a pore diameter of at least 7À5 Š; wherein the aromatic compound having at least four methyl groups has previously been prepared by reacting methanol, methyl chloride or dimethyl ether with a methyl-substituted aromatic compound having fewer methyl groups, under alkylation conditions, in the vapour phase, in the presence of an alkylation catalyst which comprises an acid zeolite having a pore diameter of at least 7À5 Š. Alternatively (a) toluene, (b) the polymethylbenzene and (c) methanol, methyl chloride or dimethyl ether may all be reacted together in the vapour phase under the same conditions to produce p-xylene. The reaction may be carried out in the presence of hydrogen. The zeolite catalyst may be offretite, zeoliteomega, mordenite, faujasite, or zeolites X or Y from which most of the alkali metal ions have been removed. |
