Application of microwave plasma technology to convert carbon dioxide (CO2) into high value products: A review

The most important challenge faced by mankind in the 21st century is the global warming issues associated with the global energy demand. A sustainable and low carbon-based energy economy must be developed to reduce the dependency on non-renewable fossil fuels. Other than exploring renewable energy technology, such as solar, hydro, and wind, recycling and utilization of carbon dioxide (CO2) in synthesizing of high value-added products is also an alternative solution to mitigate climate change. As a potential technology, the plasma-based decomposition of CO2 has received a lot of interest, especially microwave discharge due to its outstanding ability to produce non-equilibrium plasma with high ionization power, to convert CO2 in an energy-efficient manner, and others. Hence, this paper is written to provide an overview of the microwave plasma technology on CO2 conversion. The basic theory of plasma technology has also been discussed to brief the readers, particularly the non-specialist, on the technical background. The parameters that affect the performance of the CO2 conversion process under microwave discharge such as pressure, microwave power supply, gas flow rate/pattern, co-reactant, and catalyst, are also highlighted. To sum up, the prospects and challenges for the commercialization of CO2 utilization, such as methane(CH4) with CO2 reforming in syngas production, using microwave plasma technology have also been emphasized.