Intensifying carbon capture using a small, flexible, and low-cost reactor.

Abstract

Carbon capture is one of the means for mitigating the impact of greenhouse gas emissions. Several carbon capture methods are available, the most promising of which appears to be that involving a chemical reaction. This study attempts to intensify the chemical absorption of carbon dioxide into an aqueous solution of sodium hydroxide using a novel reactor equipped with a new type of static mixers. The efficiency of the reactor in removing carbon dioxide was determined by quantifying the volumetric mass transfer coefficient (kLa), CO₂ removal efficiency, and specific energy consumption as a function of various process parameters. These include gas and liquid flow rates and mixer geometry. The volumetric mass transfer coefficient and efficiency were found to increase with liquid superficial velocity and gas volume fraction up to 1.3563s⁻¹ and 98percent, respectively. Additionally, it was found that the screen geometry greatly affects the mass transfer operation whereby the screens having smaller open area yielded the highest kLa values. In this investigation, kLa values were found to be comparable and even higher than other gas-liquid contactors used for the CO₂ chemisorption into NaOH, namely, bubble columns, packed beds and rotating packed beds.