| abstract |
Isomerization of xylenes admixed with other alkyl aromatics of at least eight carbon atoms, particularly ethylbenzene, is conducted at essentially atmospheric pressure at 800-1000° F. with a zeolite such as zeolite ZSM-5 the acid activity of which has been reduced. The operating conditions prescribed, in combination with the reduction of activity of the zeolite, permit replacement by a catalyst containing a zeolite such as ZSM-5 of amorphous silica- alumina catalyst widely used in existing isomerization plants, with great increase in the effectiveness of such plants' operation. Substantially the sole by-products resulting from operation in accordance with the invention are benzene and toluene. |