Modelling and optimisation by response surface technique for adsorption of carbon dioxide by aminated biosilica/alginate composite: Experiments, characterisation and regeneration studies

Recently, there has been interest in designing recyclable and economical material for actual environmental remediation. In the present research work, amine-functionalised biosilica/alginate (NH2-SiO2/ALG) composite was evaluated for efficient capture of carbon dioxide (CO2). The morphological and textural properties of NH2-SiO2/ALG composite were comprehensively characterised by BET, SEM, XRD, TGA, and FTIR techniques. The impact of influential factors on the adsorption efficiency procedure was explored in a fixed-bed reactor and the corresponding breakthrough curves were plotted. The optimum value for CO2 removal efficiency (RE)% was predicted as 93.08% at 40 degrees C temperature, 40 mL/min gas flow rate, and 5% moisture content. Under these conditions, the actual CO2 RE% was achieved 92.4%. The exothermic isosteric heat of adsorption (IHA) was found as 25.3-34.8 kJ/mol representing physical interactions between NH2-SiO2/ALG and CO2 molecules. Regeneration tests showed that the synthesised NH2-SiO2/ALG can be effectively recovered and used in multiple runs.