Physical absorption of carbon dioxide was investigated in a wetted wall column (WWC) using a nanofluid containing titanium dioxide. Central composite response surface design (CCD) has been applied to give useful information about the main and interaction effects of the operational parameters. A quadratic mathematical model has been derived to clearly give a proper model for obtained experimental observations. The model adequacy has been analyzed by the use of analysis of variance (ANOVA), R‐squared coefficients, and lack of fit tests. The predicted values were found to be in good agreement with the general trend of experimental results. The interactive effects of the three effective absorption variables, namely temperature, liquid flow rate, and nanofluid concentration have been evaluated at five levels on the liquid mass transfer coefficient. Measurements of liquid‐side mass transfer coefficient elucidated that the absorption temperature of 25°C, the nanofluid flow rate of 299.88 mL/min, and the nanofluid concentration of 1.0%w, considerably enhances the absorption of carbon dioxide over twice.
