Isomerization of xylenes

Claim 1

A PROCESS WHICH COMPRISES CONTACTING UNDER SUBSTANTIALLY ANHYDROUS CONDITION A FEED COMPRISING ESSENTIALLY A MEMBER OF THE CLASS CONSISTING OF ORTHO-XYLENE, PARA-XYLENE, MIXTURES THEREOF AND MIXTURES OF META-XYLENE AND AT LEAST ONE OTHER XYLENE ISOMER WHEREIN THE META-XYLENE IS PRESENT IN AN AMOUNT APPRECIABLE LESS THAN THE THEORETICAL THERMODYNAMIC EQUILIBRIUM AMOUNT, WITH BETWEEN ABOUT 1 MOL AND 3 MOLS OF BF3 PER MOL OF XYLENE IN SAID FEED AND WITH BETWEEN ABOUT 100 AND 300 VOLUME PERCENT OF LIQUID HF BASED ON SAID FEED TO FORM A SINGLE PHASE HOMOGENEOUS SOLUTION OF SAID FEED AND BF3 IN SAID LIQUID HF, MAINTAINING SAID SOLUTION AT A TEMPERATURE BETWEEN ABOUT 50* AND 85* F. FOR A TIME AT LEAST SUFFICIENT TO PRODUCE A REACTION PRODUCT MIXTURE CONTAINING AT LEAST ABOUT 80 MOL PERCENT OF METAXYLENE BUT NOT LONG ENOUGH TO PRODUCE ESSENTIALLY ANY SIDE-REACTION PRODUCTS AND REMOVING THE HF AND BF3 FROM THE REACTION PRODUCT MIXTURE.