Nickel Nanoparticles for Enhancing Carbon Capture

Abstract

Hydration reaction of CO 2 is one of the rate limiting steps for CO 2 absorption (in aqueous solutions) and aqueous CO 2 mineralization. The catalytic activity of nickel nanoparticles (NiNPs) for CO 2 hydration is studied at different temperatures, pH, and low CO 2 partial pressures to mimic the true flue gas conditions. Results show that NiNPs can work as active catalyst for hydration of CO 2 in applications such as CO 2 separation and CO 2 mineralization. The NiNPs display optimum activity within 20–30°C and at pH value <8. NiNPs show catalytic activity even at low CO 2 partial pressures (12 vol%). In 50 wt% K 2 CO 3 solution, an enhancement of 77% is observed in the rate of CO 2 absorption with NiNPs. Commercially, CO 2 saturated K 2 CO 3 solutions are usually regenerated at 150°C; at these conditions, NiNPs show no considerable surface oxidation. They still exhibit catalytic activity for hydration reaction of CO 2 . CO 2 absorption and mineralization (as CaCO 3 ) in DI water are three times higher in presence of NiNPs. Calcite (CaCO 3 ) particles precipitated in presence of NiNPs are spherical in morphology.