Thermal Carbon Dioxide Splitting: A Summary of the Peer-Reviewed Scientific Literature

Abstract

Increasing concentrations of carbon dioxide (CO~2~) in the atmosphere have stimulated significant global research and development efforts regarding the reduction in CO~2~ emissions from all point and non-point sources. In addition to technologies that do not use carbon feedstocks or which capture and "permanently" store CO~2~ (i.e., sequestration), there is considerable worldwide interest among the academic, industrial, and government communities regarding methods for dissociating waste stream carbon dioxide molecules into their constituent carbon and oxygen ("CO~2~ splitting") atoms as a final "end-of-pipe" treatment option. The splitting of carbon dioxide has also been actively discussed and researched in the space exploration and extraterrestrial colonization programs for several decades. This document summarizes the peer-reviewed open source scientific literature regarding thermal methods for carbon dioxide splitting.

CO2 Decomposition in CO2 and CO2/H2 Spark‐like Plasma Discharges at Atmospheric Pressure

“…[5,6] Thermalc onversion of CO 2 requires very high temperatures, which are practically very challenging to implement. Conversion yields of approximately 60-80 %r equiret emperatures in the regiono fa bout 3500 K [5,7] with equivalent efficiencies of approximately 50 %a nd energy costso fa round6 02 kJ mol À1 . [5] Direct thermalc atalytic splitting studies have often focusedo n pathways involvings olid carbon formation (i.e.,B oudouardr e-action),w hich has presented ac hallenginge nvironment for development of inexpensive catalytic materials.…”

“…[5] Direct thermalc atalytic splitting studies have often focusedo n pathways involvings olid carbon formation (i.e.,B oudouardr e-action),w hich has presented ac hallenginge nvironment for development of inexpensive catalytic materials. [7] Membrane approaches employing catalystsa nd solid oxide electrolyser cells, which can split CO 2 and removeO 2 in situ, have recently shown promise at reducing operating temperatures over direct thermals plitting,h owever,a pproaches to date still show very low efficiencies. [7,33] Advances in microwave-heated thermal catalytic reactors have also shown thermalr eductionsw ith reports of approximately 2f actor conversion increaseso vert he use of direct thermalheating.…”

“…[7] Membrane approaches employing catalystsa nd solid oxide electrolyser cells, which can split CO 2 and removeO 2 in situ, have recently shown promise at reducing operating temperatures over direct thermals plitting,h owever,a pproaches to date still show very low efficiencies. [7,33] Advances in microwave-heated thermal catalytic reactors have also shown thermalr eductionsw ith reports of approximately 2f actor conversion increaseso vert he use of direct thermalheating. [28] The addition of co-reactants with relatively higher Gibbs free energy is ac ommon strategy to make CO 2 conversion thermodynamically more favourable.…”

Kinetic model of carbon nanotube production from carbon dioxide in a floating catalytic chemical vapour deposition reactor

“…However, the initial stage in the splitting of CO 2 produces carbon monoxide (CO) and oxygen 18,36,37 as shown in reaction (2).…”

“…36 Therefore, reaction (3) is the only one considered here, and this reaction on iron catalyst has long been known to produce lamentous carbon;…”