The separation of carbon dioxide by mineral waste with alkaline properties is an innovative technology for storing carbon dioxide. This experiment utilized an aqueous solution containing seawater and fly ash in a microchannel to investigate CO2 absorption. In all experiments, the concentration of CO2 in feed gas was 10.5% at atmospheric pressure. A number of variables were examined, including temperature (10–50 °C), inlet solvent flow rate (50–300 ml/h), inlet gas flow rate (50–250 ml/min), as well as fly ash to seawater ratios (1:25, 1:50, 1:75, 1:100, 1:125,1:150, 1:175 and 1:200 gr/ml). The study found that an increase in the concentration of fly ash in the solution and a higher flow rate of the solvent led to a noteworthy improvement in both the absorption percentage and volume transfer coefficient of gas-based gas. The increase in gas flow rate led to a decrease in the percentage of CO2 removal and an increase in the gas-based volumetric mass transfer coefficient. Under optimal operating conditions, absorption percentages were 96.25% and gas-based volumetric mass transfer coefficients were 63.21 (kmol h −1m−3 kPa−1) were achieved even though the temperature in the range of (10–50 °C) has a negative impact on the absorption rate. According to the overall gas-based volumetric mass transfer coefficient, microchannel reactors provide higher absorption efficiency than other mass transfer devices.
