Spatially confined catalysis-enhanced high-temperature carbon dioxide electrolysis

2015 ◽  
Vol 17 (17) ◽  
pp. 11705-11714 ◽  
Author(s):  
Liming Yang ◽  
Xingjian Xue ◽  
Kui Xie
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Solid Oxide

Spatially confined catalysis significantly improves the CO2 electrolysis with Faraday efficiency above 90% in a solid-oxide electrolyzer with a TiO2 cathode.

Integrating Catalytic Coal Gasifiers With Solid Oxide Fuel Cells

2010 ◽  
Author(s):  
Nicholas Siefert ◽  
Dushyant Shekhawat ◽  
Thomas Kalapos
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cells ◽  
High Temperature ◽  
Solid Oxide Fuel Cells ◽  
Chemical Reactions ◽  
Steam Gasification ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Entrained Flow ◽  
Coal Gasifier

A review was conducted for coal gasification technologies that integrate with solid oxide fuel cells (SOFC) to achieve system efficiencies near 60% while capturing and sequestering >90% of the carbon dioxide [1–2]. The overall system efficiency can reach 60% when a) the coal gasifier produces a syngas with a methane composition of roughly 25% on a dry volume basis, b) the carbon dioxide is separated from the methane-rich synthesis gas, c) the methane-rich syngas is sent to a SOFC, and d) the off-gases from the SOFC are recycled back to coal gasifier. The thermodynamics of this process will be reviewed and compared to conventional processes in order to highlight where available work (i.e. exergy) is lost in entrained-flow, high-temperature gasification, and where exergy is lost in hydrogen oxidation within the SOFC. The main advantage of steam gasification of coal to methane and carbon dioxide is that the amount of exergy consumed in the gasifier is small compared to conventional, high-temperature, oxygen-blown gasifiers. However, the goal of limiting the amount of exergy destruction in the gasifier has the effect of limiting the rates of chemical reactions. Thus, one of the main advantages of steam gasification leads to one of its main problems: slow reaction kinetics. While conventional entrained-flow, high-temperature gasifiers consume a sizable portion of the available work in the coal oxidation, the consumed exergy speeds up the rates of reactions. And while the rates of steam gasification reactions can be increased through the use of catalysts, only a few catalysts can meet cost requirements because there is often significant deactivation due to chemical reactions between the inorganic species in the coal and the catalyst. Previous research into increasing the kinetics of steam gasification will be reviewed. The goal of this paper is to highlight both the challenges and advantages of integrating catalytic coal gasifiers with SOFCs.

scholarly journals Improving the Efficiency of High-Temperature Electrolysis of Carbon Dioxide in a Solid Oxide Cell

2019 ◽  
Vol 91 (1) ◽  
pp. 2623-2630
Author(s):  
Ann V Call ◽  
Thomas D Holmes ◽  
Khelifa Yanallah ◽  
Pratik D Desai ◽  
William B Zimmerman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Solid Oxide ◽  
Solid Oxide Cell ◽  
High Temperature Electrolysis

scholarly journals Thermodynamic analysis of high temperature steam and carbon dioxide systems in solid oxide cells

2019 ◽  
Vol 3 (8) ◽  
pp. 2076-2086 ◽  
Author(s):  
Petr Vágner ◽  
Roman Kodým ◽  
Karel Bouzek
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Thermodynamic Analysis ◽  
Solid Oxide ◽  
High Temperature Steam

A thermodynamic analysis of the process in solid oxide cells with H2O and CO2 (SOCc) was performed based on the data available in the open literature.

A New Concept for High Temperature Fuel Cell Hybrid Systems Using Supercritical Carbon Dioxide

2009 ◽  
Vol 6 (2) ◽  
Author(s):  
D. Sánchez ◽  
R. Chacartegui ◽  
F. Jiménez-Espadafor ◽  
T. Sánchez
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Supercritical Carbon Dioxide ◽  
Hybrid Systems ◽  
Cell Hybrid ◽  
Gas Turbines ◽  
Solid Oxide ◽  
Molten Carbonate

Hybrid power systems based on high temperature fuel cells are a promising technology for the forthcoming distributed power generation market. For the most extended configuration, these systems comprise a fuel cell and a conventional recuperative gas turbine engine bottoming cycle, which recovers waste heat from the cell exhaust and converts it into useful work. The ability of these gas turbines to produce useful work relies strongly on a high fuel cell operating temperature. Thus, if molten carbonate fuel cells or the new generation intermediate temperature solid oxide fuel cells are used, the efficiency and power capacity of the hybrid system decrease dramatically. In this work, carbon dioxide is proposed as the working fluid for a closed supercritical bottoming cycle, which is expected to perform better for intermediate temperature heat recovery applications than the air cycle. Elementary fuel cell lumped-volume models for both solid oxide and molten carbonate are used in conjunction with a Brayton cycle thermodynamic simulator capable of working with open/closed and air/carbon dioxide systems. This paper shows that, even though the new cycle is coupled with an atmospheric fuel cell, it is still able to achieve the same overall system efficiency and rated power than the best conventional cycles being currently considered. Furthermore, under certain operating conditions, the performance of the new hybrid systems beats that of existing pressurized fuel cell hybrid systems with conventional gas turbines. From the results, it is concluded that the supercritical carbon dioxide bottoming cycle holds a very high potential as an efficient power generator for hybrid systems. However, costs and balance of plant analysis will have to be carried out in the future to check its feasibility.

scholarly journals Direct Solid Oxide Electrolysis of Carbon Dioxide: Analysis of Performance and Processes

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1390
Author(s):  
Severin Foit ◽  
Lucy Dittrich ◽  
Tobias Duyster ◽  
Izaak Vinke ◽  
Rüdiger-A. Eichel ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Electrochemical Impedance ◽  
Solid Oxide ◽  
Current Voltage ◽  
Conversion Rates ◽  
Temperature Load ◽  
Carbon Dioxide Analysis ◽  
Current Densities ◽  
Analysis Of Performance

Chemical industries rely heavily on fossil resources for the production of carbon-based chemicals. A possible transformation towards sustainability is the usage of carbon dioxide as a source of carbon. Carbon dioxide is activated for follow-up reactions by its conversion to carbon monoxide. This can be accomplished by electrochemical reduction in solid oxide cells. In this work, we investigate the process performance of the direct high-temperature CO2 electrolysis by current-voltage characteristics (iV) and Electrochemical Impedance Spectroscopy (EIS) experiments. Variations of the operation parameters temperature, load, fuel utilization, feed gas ratio and flow rate show the versatility of the procedure with maintaining high current densities of 0.75 up to 1.5 A·cm−2, therefore resulting in high conversion rates. The potential of the high-temperature carbon dioxide electrolysis as a suitable enabler for the activation of CO2 as a chemical feedstock is therefore appointed and shown.

scholarly journals Carbon Neutral Production of Syngas via High Temperature Electrolytic Reduction of Steam and CO2

2007 ◽  
Author(s):  
C. Stoots ◽  
J. O’Brien ◽  
J. Hartvigsen
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Computer Model ◽  
National Laboratory ◽  
Electrolytic Reduction ◽  
Solid Oxide ◽  
Gas Chromatograph ◽  
Open Cell ◽  
Idaho National Laboratory ◽  
Operating Temperatures

This paper presents the most recent results of experiments conducted at the Idaho National Laboratory (INL) studying coelectrolysis of steam and carbon dioxide in solid-oxide electrolysis stacks. Two 10-cell planar stacks were tested under various gas compositions, operating voltages, and operating temperatures. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. Measured outlet compositions, open cell potentials, and coelectrolysis thermal neutral voltages compared reasonably well with a coelectrolysis computer model developed at the INL. Stack ASRs did not change significantly when switching from electrolysis to coelectrolysis operation.

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