Methanol conversion on acidic ZSM-5, offretite, and mordenite zeolites: a comparative study of the formation and stability of coke deposits

Journal Article · Wed Jul 01 04:00:00 EDT 1981 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(81)90322-5· OSTI ID:6318009

Dejaifve, P ^[1]; Auroux, A; Gravelle, P C; Vedrine, J C; Gabelica, Z; Derouane, E G

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1. Institute de Recherches sur la Catalyse (CNRS), Villeurbanne, France

The deposition of carbonaceous residues, leading to aging and modifications in the acidic properties of three zeolite samples differing by the size and shape of their interconnecting channel networks (ZSM-5, offretite, and mordenite), has been investigated during the conversion reaction of methanol to hydrocarbons. Catalytic tests, thermogravimetry, and microcalorimetry are used as complementary techniques. For zeolite ZSM-5, it is observed that carbonaceous residues are primarily formed on the outer surface of the crystallites, resulting only in a slight modification of its molecular shape-selective properties and producing a high resistance to aging. For offretite and mordenite, by contrast, the channels are large enough to accommodate carbonaceous residues, which leads to a drastic loss of catalytic activity and a very fast aging. The intimate nature of the channel network is shown to play a determining role in the coke formation and in the ease of removal of carbonaceous deposit. The role played by the shape-selective properties of the zeolites on their behavior towards coking and aging and also the effect of coking on the availability of Bronsted acidic sites have been particularly emphasized.

• OSTI ID: 6318009
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 70:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

090221* -- Alcohol Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
AGING
ALCOHOLS
CARBON
CARBONIZATION
CATALYSTS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COKING
DECOMPOSITION
ELEMENTS
GRAVIMETRIC ANALYSIS
HYDROGENATION
HYDROXY COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METHANOL
MINERALS
NONMETALS
ORGANIC COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
ZEOLITES