Green, safe, fast, and inexpensive removal of CO₂ from aqueous KHCO₃ solutions using a nanostructured catalyst TiO(OH)₂: A milestone toward truly low-cost CO₂ capture that can ease implementation of the Paris Agreement

With great effort, the Paris Agreement set goals designed to address climate change, but far more effort will be necessary to meet those goals due to the lack of transformational CO₂ capture technologies that are cost-effective. This research is designed to overcome the shortcomings of conventional CO₂ capture technologies (i.e. the cost, health impacts, and environmental impacts of amines) by using a titanium oxyhydroxide (TiO(OH)₂) catalyst and a potassium carbonate/bicarbonate sorbent (K₂CO₃/KHCO₃, respectively). Nanostructured TiO(OH)₂ as a catalyst is able to accelerate desorption processes; the acceleration of CO₂ desorption is of greater significance because the process consumes more energy than the sorption process. Experimental results show that the use of nanostructured TiO(OH)₂ increases the amounts of desorbed CO₂ by as much as 1200%, if not higher. Cyclic sorption-desorption testing combined with material characterization shows that both catalyst and sorbent are stable even after 50 cycles. One major benefit of the kinetic enhancement from this catalyst/sorbent system is the reduction of temperature needed to desorb CO₂; waste heat may be sufficient to provide all or most of the energy required for CO₂ capture. Thus, the energy cost of CO₂ capture will be significantly reduced, which may keep electricity prices low, avoiding a decrease in the global economy in order to avert global climate change impacts. Another significant benefit of this system is that this inorganic system is environmentally safe, clean, and non-carcinogenic.