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

摘要

Coal 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 higher plant maintenance and processing costs. It utilizes catalysts that are prone to poisoning, are costly, and require regular regeneration. In mitigation of these issues, plasma-based CO_2 dissociation technologies could probably offer a new alternative for syngas production. The plasma-based technologies are more compact, have faster response and reaction times, 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 CO_2 dissociation technology for syngas production shows that CO_2 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). CO_2 dissociation would give value to carbon dioxide as it consumes 0.33 mol of CO_2 for each mole of syngas produced. Therefore, CO_2 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 source.