Assessment of Carbon Dioxide Dissociation as a New Route for Syngas Production: A Comparative Review and Potential of Plasma-Based Technologies

Abstract

International audienceCoal gasification and natural gas reforming are regarded as mature technologies for syngas production. These technologies are however highly polluting in terms of greenhouse gas emissions; mainly carbon dioxide. Natural gas reforming is considered cleaner than coal gasification but has some disadvantages in terms of plant maintenance and processing costs as they utilize catalysts which are prone to poisoning; are costly; and require regular regeneration. In mitigation of these issues, plasma-based CO2 dissociation technologies could probably offer a new alternative for syngas production. The plasma-based technologies are more compact, have faster response and reaction time, and are relatively cheaper compared to conventional gasification and reforming. Assuming that electricity is produced by a low carbon emitting (renewable or nuclear) power plant, a comparative review of CO2 dissociation technology for syngas production shows that CO2 dissociation can be competitive from an environmental point of view, but would face several challenges with the current plasma technologies available. Indeed, the results show that for current plasma processes to be competitive with conventional processes for syngas production, the energy efficiency, conversion rate, and processing mass flow rates of the unit operations would have to be simultaneously increased. Syngas production would also be highly dependent on the specific energy input and characteristics of the plasma (technology, electric field, power, etc.). CO2 dissociation would give value to carbon dioxide as it consumes 0.33 moles of CO2 for each mole of syngas produced. Therefore, CO2 dissociation can be attractive as a possible option for the conversion of electrical energy to chemical energy, especially when the electrical energy is from a renewable and low cost electricity production. Keywords: carbon dioxide, CO2 dissociation, syngas production, reforming, plasma, coal gasification, natural gas reformin

Optimization of CO2 Conversion in a Cylindrical Dielectric Barrier Discharge Reactor Using Design of Experiments

“…However, increasing the discharge power and CO 2 flow rate has an opposite effect on CO 2 conversion and energy efficiency. [40,49] For example, higher discharge power results in higher CO 2 conversion but lowers the energy efficiency of the process at a fixed CO 2 flow rate, whereas higher reactant flow leads to higher energy efficiency of the plasma process but significantly decreases the conversion of CO 2 . Figure 9 summarizes the CO 2 conversion and energy efficiency of the plasma processing of pure CO 2 using different atmospheric pressure plasma sources.…”

Carbon dioxide dissociation to carbon monoxide by non-thermal plasma

“…Some authors stated that in nonthermal plasma system, vibrational excitation of molecules is favored for most non-electronegative molecules such as CO 2 in endothermic reactions [24,25]. In this case, chemical process occurs via the formation of an intermediate state from its ground electronic state to a low valence excited state CO 2 *( 3 B 2 ), which stimulates the dissociation reaction [18]. Aerts et al [26] suggest that electron impact dissociation has the largest contribution to CO 2 reactivity.…”

“…Apart from reforming reactions, the direct decomposition of carbon dioxide to carbon monoxide could be an interesting way to valorize CO 2 and to limit the formation of side products from hydrocarbons [18]. Non-thermal plasma can promote the highly endothermic reaction (Eq.…”

Communication: Enhanced dissociative chemisorption of CO2 via vibrational excitation

“…A promising approach to dissociate CO 2 is to use non-thermal plasmas, in which molecules may be internally hot but translationally cold. 5 In such an environment, chemical processes do not necessarily follow reaction pathways dominant in thermal equilibrium. Indeed, Fridman has reported efficient CO 2 dissociation in such plasmas, presumably via vibrationally excited CO 2 produced by electron-molecule scattering.…”