Enhanced CO2 Capture Using TiO2 Nanoparticle-Functionalized Solvent: A Study on Desorption Experiments

Cutting CO2 emissions is crucial to face of climate change, and one of the most tried and true means of post-combustion CO2 capture is by way of chemical absorption. In this work, the effect of titanium dioxide (TiO2) nanoparticles in a 25 wt% potassium carbonate (K2CO3) solution on solvent regeneration is investigated. This research follows the previous work in which the effect of nanofluids was evaluated on CO2 absorption. Desorption was studied at three different temperatures (343.15, 348.15 and 353.15 K), using the absorbent fluid with and without 0.06 wt% TiO2 nanoparticles. The results indicate that the nanofluid enhanced the CO2 release rates, also reducing energy consumption. The mass transfer was intensified by the presence of nanoparticles, which in turn increased CO2 diffusivity and influenced the liquid boundary layer, resulting in an enhanced desorption rate, because of the higher diffusivity. These enhancements were achieved with negligible modifications to the fluid properties, i.e., viscosity. In summary, application of TiO2-enhanced K2CO3 solutions is a practical approach to enhance CO2 removal performance and reduce operating costs such that CO2 capture is beginning to be environmentally and economically more competitive for the existing system retrofit.