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In this research, porous benzene‐based hypercrosslinked polymeric adsorbents with different morphological properties were synthesized through Friedel–Crafts alkylation reaction. The resulting samples were applied for CO2 capture at different operational conditions. Two modelling approaches, including artificial neural network (radial basis function [RBF] and multi layer perceptron [MLP]) and response surface methodology (RSM), were employed to investigate the effect of independent parameters on adsorption capacity. A semi‐empirical quadratic model for adsorption capacity was presented based on RSM‐central composite design technique. Additionally, the optimal structure of RBF was determined with 200 neurons, and the optimal structure of MLP was determined with three hidden layers and 10, 8, and 7 neurons. The modelling results demonstrate the better prediction of MLP and RBF approaches than the RSM method with correlation coefficient values of 0.999, 0.989, and 0.931, respectively. Finally, process optimization was carried out using RSM optimization module and the optimized values of synthesis time, crosslinker ratio (formaldehyde dimethyl acetal [FDA]/benzene), adsorption time, pressure, and temperature were obtained at 10.11 h, 1, 220 s, 9 bar, and 55°C, respectively. The optimum value of CO2 uptake capacity was obtained around 167 (mg/g). [ABSTRACT FROM AUTHOR]

In this work, benzene based hypercrosslinked polymer (HCP) as an adsorbent was modified using amine group to enhance CO2 uptake capability and selectivity. Based on BET analysis result, the HCP and the modified HCP provide surface area of 806 (m2 g−1) and micropore volume of 453 (m2 g−1) and 0.19 (cm3 g−1) and 0.14 (cm3 g−1), respectively. The CO2 and N2 gases adsorption were performed in a laboratory scale reactor at a temperature between 298 and 328 K and pressure up to 9 bar. The experimental data were evaluated using isotherm, kinetic and thermodynamic models to identify the absorbent behavior. The maximum CO2 adsorption capacity at 298 K and 9 bar was obtained 301.67 (mg g−1) for HCP and 414.41 (mg g−1) for amine modified HCP. The CO2 adsorption thermodynamic parameters assessment including enthalpy changes, entropy changes, and Gibbs free energy changes at 298 K were resulted − 14.852 (kJ mol−1), − 0.024 (kJ mol−1 K−1), − 7.597 (kJ mol−1) for HCP and − 17.498 (kJ mol−1), − 0.029(kJ mol−1 K−1), − 8.9 (kJ mol−1) for amine functionalized HCP, respectively. Finally, the selectivity of the samples were calculated at a CO2/N2 composition of 15:85 (v/v) and 43% enhancement in adsorption selectivity at 298 K was obtained for amine modified HCP. [ABSTRACT FROM AUTHOR]