(96c) High Temperature Co-Electrolysis of Steam and Carbon Dioxide to Produce Synthesis Gas Utilizing Concentrator Photovoltaic Arrays

High Temperature Co-electrolysis of Steam and Carbon Dioxide to Produce Synthesis Gas Utilizing Concentrator Photovoltaic Arrays

Ceramatec, Inc is currently developing technology for the high temperature co-electrolysis of steam and carbon dioxide to produce synthesis gas. This technology utilizes solid oxide fuel cell materials to produce a clean stream of carbon monoxide and hydrogen. By varying the concentrations of carbon dioxide and steam, the yielded ratio of hydrogen to carbon monoxide can be modified dependent on the type of synthetic fuel desired for production.

High temperature electrolysis is substantially more efficient than existing electrolysis methods since part of the energy required to break the molecular bonds is furnished by heat. Existing proton exchange membrane electrolysis technologies operate below 100O C but high temperature electrolysis operates in the 800O C range. This higher temperature improves the efficiency significantly. The use of the materials utilized for solid oxide fuel cells matches the desired temperature range. Issues with the materials are raised, however, since the operating conditions of the electrolysis cells vary from those of solid oxide fuel cells. While some environmental conditions are beneficial, others create potential problems that Ceramatec is addressing with its research.

Ceramatec has been working on application of this high temperature technology for production of synthesis gas for production of synthetic methane for a company in Australia using solar concentrator technology as a source of heat and electricity. The Office of Naval Research has directly funded Ceramatec to investigate the production of synthetic fuels through the co-electrolysis of carbon dioxide and steam.

This paper will present results of laboratory scale high temperature co-electrolysis. The paper will present the yields of hydrogen and carbon monoxide obtained from varying input mixtures of carbon dioxide and steam. The paper will also present the results of utilizing the resultant synthesis gas to produce synthetic methane and Fischer Tropsch liquid fuels. Issues related to long term lifetime testing, commercial scale-up, and cost will be discussed.