Experimental study of carbon dioxide capture and mineral carbonation using sodium hydroxide solution

The mineral carbonation process was proposed for effective CO2 capture and utilization from flue gas streams, such as those emitted by coal-fired power plants. In the present work, an alternative technology using sodium hydroxide (NaOH) solution as an absorbent for capturing CO2 and converting it into value-added materials while mitigating emissions was provided. This research examined the use of a packed bed reactor and a bubble column reactor for CO2 absorption and carbonation of NaOH solution to produce sodium bicarbonate (NaHCO3), offering a more environmentally friendly production process compared to traditional methods. The influence of significant operating parameters, namely pH value, gas flow rate, and absorbent flow rate, on CO2 capture in a bubble column reactor was experimentally explored using NaOH solution. The formation of sodium bicarbonate during the carbonation experiment was confirmed by X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). The experimental results show a CO2 removal efficiency exceeding 95% and a NaHCO3 purity above 94% when utilizing a bubble column reactor.