English to French Science Chemistry; Chem Sci/Eng PROCESS FOR TRANSALKYLATING AROMATIC HYDROCARBONS

Also, because some of the non-aromatics have similar boiling points to benzene (benzene co-boilers), they are not readily removed to
achieve a benzene product having a desired purity for commercial applications. Although the benzene co-boilers can be extracted with a solvent, such processes are expensive and typically require additional equipment.

Accordingly, it is desirable to provide a transalkylation process that produces a high-purity benzene product.

However, it has been discovered that initial operation during the early period of a process cycle at benzene-purity-directed conditions, whilst resulting in somewhat more rapid catalyst deactivation, also reduces the production of benzene co-boilers and better enables their destruction with concomitant enabling of acceptable purity of the benzene fraction of the transalkylation reaction product stream.

Benzene-purity-directed operating conditions are applied to produce a product stream that achieves a benzene purity of at least 99.9% benzene by distillation during an initial portion of the process cycle.