The disproportionation of xylenes over a cay zeolite catalyst

Journal Article · Sun Jan 01 04:00:00 EST 1978 · Int. Chem. Eng.; (United States)

OSTI ID:5996627

Mortikov, E S; Kononov, N F; Leontev, A S; Kozlov, B M; Lakiza, S M; Minachev, Kh M

The disproportionation of xylenes over a CaY zeolite catalyst was studied at 300/sup 0/-500/sup 0/C, 15 kg-f/sq cm, and 0.61/hr space velocity in a single-pass reactor over a single 50 cc portion of catalyst. The average conversion of m-xylene after five hours increased with increasing temperature to a maximum of 72% at 400/sup 0/-450/sup 0/C and then dropped off to 45% at 500/sup 0/C. During the initial contact, conversion at 500/sup 0/C was 74%, but this fell to 18% after five hours. The amount of deactivating coke formed after five hours was 3% of the catalyst weight at 300/sup 0/-350/sup 0/C and 12-15% at 450/sup 0/-500/sup 0/C. The main disproportionation products were toluene and trimethylbenzenes, the latter fraction being 8-10% hemimellitene, 20-25% mesitylene, and 68-72% pseudocumene. The yield of trimethylbenzenes reached 22 mole % at 400/sup 0/C and declined to 9 mole % at 500/sup 0/C. The yield of tetramethylbenzenes (50-51% isodurene, 38% durene, and 7-12% prehnitol) also peaked at 400/sup 0/C. At 400/sup 0/-450/sup 0/C, disproportionation accounted for 45% and isomerization to o- and p-xylene for 26% of the products. In the case of o-xylene, total conversion was 88-90% at 450/sup 0/-475/sup 0/C; isomerization accounted for 55% and disproportionation for only 35% of the yields. All the product yields were increased by increasing pressure. Table and graph.

• Research Organization: Inst. of Organic Chemistry, Academy of Science, USSR
• OSTI ID: 5996627
• Journal Information: Int. Chem. Eng.; (United States), Journal Name: Int. Chem. Eng.; (United States) Vol. 18:1; ISSN INCEA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
AROMATICS
BENZENE
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
DEACTIVATION
HIGH TEMPERATURE
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOMERIZATION
MATERIALS
MINERALS
ORGANIC COMPOUNDS
OXIDATION
PHYSICAL PROPERTIES
REDUCTION
THERMODYNAMIC PROPERTIES
TOLUENE
XYLENES
ZEOLITES