Improved Process of Hydrogenating Benzene

• Main Authors: DANIEL LUMBROSO, QUANG DANG VU, ROBERT ODELLO
• Format: Patent
• Language: English
• Published: 19.11.1969
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; GENERAL METHODS OF ORGANIC CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

1,171,564. Hydrogenating benzene. INSTITUT FRANCAIS DU PETROLE DES CARBURANTS ET LUBRIFIANTS. 22 March, 1968 [24 March, 1967; 25 April, 1967], No. 13997/68. Heading C5E. In a process for hydrogenating benzene to cyclohexane in the liquid phase by means of a molecular hydrogen-containing gas in the presence of a suspension of solid hydrogenation catalyst (e.g. Raney nickel), a comparatively low amount of catalyst is used during the starting period of operation, and thereafter complementary amounts of catalyst are introduced until the density of the catalyst in the liquid phase attains a maximum desired value, and then catalyst injection is continued either continuously or stepwise whilst withdrawing either continuously or stepwise an amount of catalyst substantially equal to that introduced. The catalyst additions are conveniently made when the benzene content of the cyclohexane product becomes too high. Conditions may be adjusted for either complete or partial hydrogenation (95-99%), and in the latter case a further hydrogenation stage using a fixed-bed catalyst may follow. The hydrogen-containing gas may be first contacted with liquid cyclohexane, or with a hydrocarbon cut having more than 10 carbon atoms followed by liquid cyclohexane.