N-OLEFIN SKELETAL ISOMERIZATION PROCESS

• Main Authors: FUNG, SHIU, LUN, ANTHONY, APELIAN, MINAS, ROBERT, HUSS, ALBIN, JR, RAHMIM, IRAJ, ISAAC
• Format: Patent
• Language: English; French
• Published: 25.11.1993
• Edition: 5
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; CRACKING HYDROCARBON OILS; FUELS; GENERAL METHODS OF ORGANIC CHEMISTRY; LUBRICANTS; METALLURGY; MINERAL WAXES; ORGANIC CHEMISTRY; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVEHYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, ORGASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; TECHNICAL GASES CONTAINING CARBON MONOXIDE; THEIR RELEVANT APPARATUS; TRANSPORTING

In a process for skeletal isomerization of linear olefins to iso-olefins, e.g., n-butenes to isobutylene, over a catalyst comprising medium pore zeolite, e.g., a zeolite selected from ZSM-22, ZSM-23, and ZSM-35, the zeolite is pretreated with a dicarboxylic acid, e.g., oxalic acid. The pretreatment significantly reduces aging rate and increases cycle length of the catalyst. Dans un procédé d'isomérisation schématique d'oléfines linéaires en iso-oléfines, par ex. de n-butènes en isobutylène, sur un catalyseur comportant de la zéolithe à pores moyens, par ex. une zéolithe sélectionnée parmi ZSM-22, ZSM-23 et ZSM-35, la zéolithe est prétraitée à l'aide d'un acide dicarboxylique, par ex. de l'acide oxalique. Ce prétraitement réduit de manière sensible la vitesse de vieillissement et accroît la longueur de cycle du catalyseur.