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Title: Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol

Abstract

The catalytic conversion of coal-derived syngas to C{sub 2+} alcohols and oxygenates has attracted great attention due to their potential as chemical intermediates and fuel components. This is particularly true of ethanol, which can serve as a transportation fuel blending agent, as well as a hydrogen carrier. A thermodynamic analysis of CO hydrogenation to ethanol that does not allow for byproducts such as methane or methanol shows that the reaction: 2 CO + 4 H{sub 2} {yields} C{sub 2}H{sub 5}OH + H{sub 2}O is thermodynamically favorable at conditions of practical interest (e.g,30 bar, {approx}< 250 C). However, when methane is included in the equilibrium analysis, no ethanol is formed at any conditions even approximating those that would be industrially practical. This means that undesired products (primarily methane and/or CO{sub 2}) must be kinetically limited. This is the job of a catalyst. The mechanism of CO hydrogenation leading to ethanol is complex. The key step is the formation of the initial C-C bond. Catalysts that are selective for EtOH can be divided into four classes: (a) Rh-based catalysts, (b) promoted Cu catalysts, (c) modified Fischer-Tropsch catalysts, or (d) Mo-sulfides and phosphides. This project focuses on Rh- and Cu-based catalysts. The logicmore » was that (a) Rh-based catalysts are clearly the most selective for EtOH (but these catalysts can be costly), and (b) Cu-based catalysts appear to be the most selective of the non-Rh catalysts (and are less costly). In addition, Pd-based catalysts were studied since Pd is known for catalyzing CO hydrogenation to produce methanol, similar to copper. Approach. The overall approach of this project was based on (a) computational catalysis to identify optimum surfaces for the selective conversion of syngas to ethanol; (b) synthesis of surfaces approaching these ideal atomic structures, (c) specialized characterization to determine the extent to which the actual catalyst has these structures, and (d) testing at realistic conditions (e.g., elevated pressures) and differential conversions (to measure true kinetics, to avoid deactivation, and to avoid condensable concentrations of products in the outlet gas).« less

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Board Of Supervisors of Louisiana State University
Sponsoring Org.:
USDOE
OSTI Identifier:
1032857
DOE Contract Number:  
FC26-06NT43024
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
03 NATURAL GAS; 08 HYDROGEN; 10 SYNTHETIC FUELS; ALCOHOLS; CATALYSIS; CATALYSTS; COPPER; DEACTIVATION; ETHANOL; HYDROGEN; HYDROGENATION; KINETICS; METHANE; METHANOL; PHOSPHIDES; SYNTHESIS; TESTING; THERMODYNAMICS

Citation Formats

Spivery, James, Harrison, Doug, Earle, John, Goodwin, James, Bruce, David, Mo, Xunhau, Torres, Walter, Vis Viswanathan, Joe Allison, Sadok, Rick, Overbury, Steve, and Schwartz, Viviana. Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol. United States: N. p., 2011. Web. doi:10.2172/1032857.
Spivery, James, Harrison, Doug, Earle, John, Goodwin, James, Bruce, David, Mo, Xunhau, Torres, Walter, Vis Viswanathan, Joe Allison, Sadok, Rick, Overbury, Steve, & Schwartz, Viviana. Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol. United States. https://doi.org/10.2172/1032857
Spivery, James, Harrison, Doug, Earle, John, Goodwin, James, Bruce, David, Mo, Xunhau, Torres, Walter, Vis Viswanathan, Joe Allison, Sadok, Rick, Overbury, Steve, and Schwartz, Viviana. 2011. "Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol". United States. https://doi.org/10.2172/1032857. https://www.osti.gov/servlets/purl/1032857.
@article{osti_1032857,
title = {Catalytic Process for the Conversion of Coal-derived Syngas to Ethanol},
author = {Spivery, James and Harrison, Doug and Earle, John and Goodwin, James and Bruce, David and Mo, Xunhau and Torres, Walter and Vis Viswanathan, Joe Allison and Sadok, Rick and Overbury, Steve and Schwartz, Viviana},
abstractNote = {The catalytic conversion of coal-derived syngas to C{sub 2+} alcohols and oxygenates has attracted great attention due to their potential as chemical intermediates and fuel components. This is particularly true of ethanol, which can serve as a transportation fuel blending agent, as well as a hydrogen carrier. A thermodynamic analysis of CO hydrogenation to ethanol that does not allow for byproducts such as methane or methanol shows that the reaction: 2 CO + 4 H{sub 2} {yields} C{sub 2}H{sub 5}OH + H{sub 2}O is thermodynamically favorable at conditions of practical interest (e.g,30 bar, {approx}< 250 C). However, when methane is included in the equilibrium analysis, no ethanol is formed at any conditions even approximating those that would be industrially practical. This means that undesired products (primarily methane and/or CO{sub 2}) must be kinetically limited. This is the job of a catalyst. The mechanism of CO hydrogenation leading to ethanol is complex. The key step is the formation of the initial C-C bond. Catalysts that are selective for EtOH can be divided into four classes: (a) Rh-based catalysts, (b) promoted Cu catalysts, (c) modified Fischer-Tropsch catalysts, or (d) Mo-sulfides and phosphides. This project focuses on Rh- and Cu-based catalysts. The logic was that (a) Rh-based catalysts are clearly the most selective for EtOH (but these catalysts can be costly), and (b) Cu-based catalysts appear to be the most selective of the non-Rh catalysts (and are less costly). In addition, Pd-based catalysts were studied since Pd is known for catalyzing CO hydrogenation to produce methanol, similar to copper. Approach. The overall approach of this project was based on (a) computational catalysis to identify optimum surfaces for the selective conversion of syngas to ethanol; (b) synthesis of surfaces approaching these ideal atomic structures, (c) specialized characterization to determine the extent to which the actual catalyst has these structures, and (d) testing at realistic conditions (e.g., elevated pressures) and differential conversions (to measure true kinetics, to avoid deactivation, and to avoid condensable concentrations of products in the outlet gas).},
doi = {10.2172/1032857},
url = {https://www.osti.gov/biblio/1032857}, journal = {},
number = ,
volume = ,
place = {United States},
year = {2011},
month = {7}
}