Kinetics of reactions of C/sub 8/ olefins on HY zeolite

Journal Article · Tue Dec 01 00:00:00 EST 1987 · J. Catal.; (United States)

OSTI ID:5204528

Abbot, J; Wojciechowski, B W

Reactions of two C/sub 8/ olefins (n-octene and 2,4,4-trimethylpentene) have been studied on HY at 300/sup 0/C. Skeletal isomerization is the dominant reaction of n-octene (initial selectivity 0.98), while cracking is the dominant reaction of 2,4,4-trimethylpentene (initial selectivity 0.80). Conversion rates of both olefins can be fitted by a kinetic expression previously applied to the cracking of n-paraffins on HY at 400/sup 0/C. The kinetic rate constants for reaction of these olefins, independent of adsorption parameters, have been calculated, and show that the sum of the rate constants for cracking 2,4,4-trimethylpentene is approx. 160 times greater than that for skeletal isomerization of n-octene. The parameters obtained show that adsorption of olefins on HY decreases with an increased degree of branching. Methylheptenes are less strongly adsorbed than linear octenes. Trimethylpentenes are less strongly adsorbed than isobutene. This trend is also observed by comparing initial coke formation on HY from the two olefin feedstocks, which shows that n-octenes are adsorbed to a significantly higher extent than 2,4,4-trimethylpentene. The decay parameters show that aging occurs much more rapidly for 2,4,4-trimethylpentene than for n-octene. There appears to be no simple relationship between total coke deposited and catalyst deactivation.

• Research Organization: Queen's Univ., Kingston, Ontario (Canada)
• OSTI ID: 5204528
• Journal Information: J. Catal.; (United States), Vol. 108:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
OCTENES
CATALYTIC CRACKING
ISOMERIZATION
PENTENES
ZEOLITES
CATALYTIC EFFECTS
ADSORPTION
CATALYSTS
CHEMICAL REACTION KINETICS
COKE
DEACTIVATION
DEPOSITION
ALKENES
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
KINETICS
MATERIALS
MINERALS
ORGANIC COMPOUNDS
PYROLYSIS
REACTION KINETICS
SORPTION
THERMOCHEMICAL PROCESSES
020400* - Petroleum- Processing