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

Title: Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts

Abstract

Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{submore » 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.« less

Authors:
Publication Date:
Research Org.:
Lawrence Berkeley Lab., CA (United States)
Sponsoring Org.:
USDOE; USDOE, Washington, DC (United States)
OSTI Identifier:
5128268
Report Number(s):
LBL-31822
ON: DE92017085
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Technical Report
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; FISCHER-TROPSCH SYNTHESIS; CATALYSTS; HYDROCARBONS; CARBON MONOXIDE; CHEMICAL REACTION KINETICS; COMPUTER CODES; DIFFERENTIAL EQUATIONS; GAS CHROMATOGRAPHY; HYDROGEN; MASS SPECTROSCOPY; RUTHENIUM; TITANIUM OXIDES; TRACER TECHNIQUES; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; CHROMATOGRAPHY; ELEMENTS; EQUATIONS; ISOTOPE APPLICATIONS; KINETICS; METALS; NONMETALS; ORGANIC COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; PLATINUM METALS; REACTION KINETICS; SEPARATION PROCESSES; SPECTROSCOPY; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; TRANSITION ELEMENTS; 010405* - Coal, Lignite, & Peat- Hydrogenation & Liquefaction; 010408 - Coal, Lignite, & Peat- C1 Processes- (1987-)

Citation Formats

Krishna, K R. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts. United States: N. p., 1992. Web. doi:10.2172/5128268.
Krishna, K R. Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts. United States. doi:10.2172/5128268.
Krishna, K R. Wed . "Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts". United States. doi:10.2172/5128268. https://www.osti.gov/servlets/purl/5128268.
@article{osti_5128268,
title = {Isotopic tracer studies of Fischer-Tropsch Synthesis over Ru/TiO sub 2 catalysts},
author = {Krishna, K R},
abstractNote = {Fischer-Tropsch synthesis is a process in which CO and H{sub 2} react to give predominantly liquid hydrocarbons. The reaction can be considered a special type of polymerization in which the monomer is produced in situ, and chain growth occurs by a sequence of independently repeated additions of the monomer to the growing chain. A investigation has been conducted to study the CO hydrogenation reaction in order to better understand catalyst deactivation and the elementary surface processes involved in chain growth. Isotopic tracers are used in conjunction with transient-response techniques in this study of Fischer-Tropsch synthesis over Ru/TiO{sub 2} catalysts. Experiments are conducted at a total pressure of 1 atmosphere, reaction temperatures of 453--498 K and D{sub 2}/CO (or H{sub 2}/CO) ratios of 2--5. Synthesis products are analyzed by gas chromatography or isotope-ratio gas chromatography-mass spectrometry. Rate constants for chain initiation, propagation and termination are evaluated under steady-state reaction conditions by using transients in isotopic composition. The activation energy for chain termination is much higher than that for propagation, accounting for the observed decrease in the chain growth parameter are also estimated. Coverages by reaction intermediates are also estimated. When small amounts of {sup 12}C-labelled ethylene are added to {sup 13}CO/H{sub 2} synthesis gas, ethylene acts as the sole chain initiator. Ethylene-derived carbon also accounts for 45% of the C{sub 1} monomer pool. 102 refs., 29 figs., 11 tabs.},
doi = {10.2172/5128268},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1992},
month = {1}
}