PURPOSE: In carrying out both the isomerization reaction of a xylene and the hydrogenation and dealkylation reaction of a specific alkyl-substituted aromatic hydrocarbon, to enable long-term operation, by reclaiming a catalyst having lowered activity through a combination of the combustion treatment of a carbonaceous substance and chlorine treatment.
CONSTITUTION: In the presence of a catalyst composition containing crystalline aluminosilicate modified with platinum, a xylene isomer not reaching a thermodynamic equilibrium composition is isomerized, and simultaneously an alkyl- substituted aromatic hydrocarbon containing ≥2C alkyl group linked to an aromatic group is hydrogenated and dealkylated. In the operation, the catalyst composition on which a carbonaceous substance is accumulated, having reduced activity, is at first brought into contact with O2-containing gas at ≤600°C, so that the carbonaceous substance is partially burned, it is brought into contact with a chlorine-containing substance and an O2-containing mixed gas at 200W 600°C, the mixed gas is replaced with an inert gas, and the catalyst is reduced with H2-containing gas at 200W600°C, so that the catalyst is reclaimed. The isomerization activity and de-ethylation reaction activity of the catalyst are recovered.
SAKAI ATSUJI
YAMAZAKI YASUO
SUMITANI KOUJI
| JPS49126589A | 1974-12-04 | |||
| JPS56147636A | 1981-11-16 |