skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The effect of oxygen on the conversion of light paraffins on ZSM-5 zeolites

Abstract

The oxygen effect in the conversion of ethane, propane, and n-butane to aromatics using two H-ZSM-5 zeolites with different Si/Al ratios is studied. The presence of small amounts of gas-phase oxygen increases benzene-toluene-xylene formation, in particular at the lower reaction temperatures (below 773 K). The enhancement factor compared to anaerobic activity is higher for the less reactive alkane (ethane) and for the less active zeolite (Si/Al = 164) which also shows the lower total oxidation activity. The formation of carbon oxides decreases considerably when the surface acidity is inhibited by potassium exchange, and the K zeolite is active only in the oxidative dehydrogenation of the alkane. However, it was found that the aerobic activity of the zeolite is also correlated to surface acidity. It is suggested that the main oxygen effect is in the first stage of alkane activation, enhancing the formation of the corresponding olefin. The creation of new active sites was attributed to the interaction of oxygen with solid-state defects forming very reactive oxygen free radical species. Their activity, however, is inhibited during reaction due the formation of carbonaceous residues.

Authors:
;  [1]
  1. Universita di Bologna (Italy)
Publication Date:
OSTI Identifier:
6911379
Resource Type:
Journal Article
Journal Name:
Journal of Catalysis; (USA)
Additional Journal Information:
Journal Volume: 115:2; Journal ID: ISSN 0021-9517
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; BUTANE; CATALYTIC REFORMING; ETHANE; OXYGEN; CATALYTIC EFFECTS; PROPANE; ALUMINIUM; AROMATICS; BENZENE; CARBON; DEACTIVATION; DEHYDROGENATION; DEPOSITION; INHIBITION; ION EXCHANGE; PH VALUE; POTASSIUM; QUANTITY RATIO; RADICALS; SILICON; SURFACE PROPERTIES; SYNTHESIS; TOLUENE; XYLENES; ZEOLITES; ALKALI METALS; ALKANES; ALKYLATED AROMATICS; CHEMICAL REACTIONS; ELEMENTS; HYDROCARBONS; INORGANIC ION EXCHANGERS; ION EXCHANGE MATERIALS; MATERIALS; METALS; MINERALS; NONMETALS; ORGANIC COMPOUNDS; REFORMER PROCESSES; SEMIMETALS; 020400* - Petroleum- Processing

Citation Formats

Centi, G, and Golinelli, G. The effect of oxygen on the conversion of light paraffins on ZSM-5 zeolites. United States: N. p., 1989. Web. doi:10.1016/0021-9517(89)90049-3.
Centi, G, & Golinelli, G. The effect of oxygen on the conversion of light paraffins on ZSM-5 zeolites. United States. doi:10.1016/0021-9517(89)90049-3.
Centi, G, and Golinelli, G. Wed . "The effect of oxygen on the conversion of light paraffins on ZSM-5 zeolites". United States. doi:10.1016/0021-9517(89)90049-3.
@article{osti_6911379,
title = {The effect of oxygen on the conversion of light paraffins on ZSM-5 zeolites},
author = {Centi, G and Golinelli, G},
abstractNote = {The oxygen effect in the conversion of ethane, propane, and n-butane to aromatics using two H-ZSM-5 zeolites with different Si/Al ratios is studied. The presence of small amounts of gas-phase oxygen increases benzene-toluene-xylene formation, in particular at the lower reaction temperatures (below 773 K). The enhancement factor compared to anaerobic activity is higher for the less reactive alkane (ethane) and for the less active zeolite (Si/Al = 164) which also shows the lower total oxidation activity. The formation of carbon oxides decreases considerably when the surface acidity is inhibited by potassium exchange, and the K zeolite is active only in the oxidative dehydrogenation of the alkane. However, it was found that the aerobic activity of the zeolite is also correlated to surface acidity. It is suggested that the main oxygen effect is in the first stage of alkane activation, enhancing the formation of the corresponding olefin. The creation of new active sites was attributed to the interaction of oxygen with solid-state defects forming very reactive oxygen free radical species. Their activity, however, is inhibited during reaction due the formation of carbonaceous residues.},
doi = {10.1016/0021-9517(89)90049-3},
journal = {Journal of Catalysis; (USA)},
issn = {0021-9517},
number = ,
volume = 115:2,
place = {United States},
year = {1989},
month = {2}
}