(337k) Carbon Capture and Aerosol Technology for CO2 Utilization

Several companies and countries are making net-zero commitments to mitigate climate change by eliminating anthropogenic CO₂ emissions by 2050. There does not exist a single solution to eliminate CO₂ emissions, hence, several technologies including carbon capture and utilization need to be advanced to address the global challenge of climate change¹. My research is focused on developing efficient pressurized oxy-combustion systems for CO₂ capture and the synthesis of advanced catalysts via single-step continuous aerosol-based processes for CO₂ conversion to chemicals and fuels.

To advance pressurized oxy-combustion power plant technology for CO₂ capture, there is a need to understand particle formation at high pressure conditions to ensure minimal particulate matter (PM) emission and reliable performance. To study PM formation of pulverized solid fuels at high pressures, I designed, fabricated and set-up a Lab scale pressurized drop-tube furnace experiment system.

I also explored catalyst synthesis for CO₂ reforming and DME production. First, to illustrate the significance of CO₂ conversion via reforming processes, I performed thermodynamic studies^2,3. The studies showed that up to 45 million tons of CO₂ per annum can be incorporated into methanol, Fischer-Tropsch liquid fuels and butyraldehyde. Consequently, I demonstrated the controlled synthesis of alumina, a conventional catalyst support for reforming, via aerosol process⁴. Currently, I am studying the synthesis of Rh/Al₂O₃ catalyst via aerosol process and designing highly dispersed and single atom Rh/Al₂O₃ catalysts for reforming of carbon dioxide.

Finally, I synthesized Cu/ZnO/MgO and Cu/ZnO/ZrO₂ for single-step DME synthesis from CO₂. Hybrid catalysts synthesized using the spray flame aerosol reactor (aerosol process) when compared to co-precipitation catalysts were found to be about 15% more active and selective to DME/methanol, hence its potential to increase the yield of DME by 33% and decrease unit cost of DME production by 25% when compared to conventional catalyst⁵.

Overall, based on my PhD research, I have gained experience on material synthesis, material characterization methods and multi-scale modelling. I am presently interested in an industry position where I can continue to be innovative while working on the development and scale up of novel processes.

1. Okonkwo and Biswas (2021), Synthesis of novel catalysts for carbon dioxide conversion to products of value, 527-556.
2. Okonkwo et al, (2020) Journal of CO₂ Utilization 39:101156
3. Okonkwo et al, (2022) Journal of CO₂ Utilization 60:101998
4. Okonkwo et al, (2022) Journal of the American Ceramic Society 105;2 1481-1490
5. Okonkwo et al, (2023) Chemical Engineering Journal (in preparation)