Simulation and optimization of CO2 capture in deep eutectic solvent–functionalized hydrotalcite using response surface method

Abstract

The continuous increase in atmospheric CO2 emissions from industrial and energy related activities has intensified climate change concerns and highlighted the need for efficient adsorbent materials for carbon capture applications. This work focuses on the simulation and optimization of the CO₂ adsorption process by Design of Experiments with response surface methodology (RSM) using experimentally prepared deep eutectic solvent (DES)-functionalized hydrotalcite (HT). The effect of four process parameters, temperature (25–80°C), inlet CO2 concentration (5-20 vol.%), DES loading (5-35 wt.%), and adsorbent dosage (0.2-0.8 g), on CO2 adsorption capacity was investigated. RSM and central composite design (CCD) were used to build a model that correlates the effect of process factors on CO₂ adsorption capacity. ANOVA results confirmed that the cubic model was statistically significant at a 95% confidence interval, indicating its suitability for accurately describing and predicating CO2 adsorption performance. The model also demonstrated good agreement between the experimental and predicated values, allowing reliable determination of the optimum process parameters. Moreover, the adsorption capacity of CO2 was determined based on the experimental data; the optimal process parameters to attain the largest CO2 adsorption capacity are 1.469 mmol CO2/g adsorbent at an inlet CO2 concentration of 14 vol.%, a temperature of 26oC, DES loading of 33.4 wt.%, and an adsorbent dosage of 0.54 g.