Synthesis and characterization of waste Styrofoam hypercrosslinked polymer as an adsorbent for CO2 capture

In this work, we used waste Styrofoam as a precursor to synthesize a hypercrosslinked polymeric (HCP) adsorbent for CO2 adsorption utilizing the Friedel–Craft procedure. The hypercrosslinked adsorbent was designed using formaldehyde dimethyl acetal (FDA) as the crosslinker. The precursor to crosslinker to catalyst ratio was 1:3:3, and the HCP synthesis was carried out for 12 h at 312.6 K. Fourier‐transform infrared spectroscopy, field emission scanning electron microscopy, and thermogravimetric analysis were used to analyze the waste Styrofoam hypercrosslinked (WSHC) adsorbent. The adsorbent attained an 802.84 m2/g Brunauer–Emmett–Teller (BET) surface area and an average pore diameter of 2.869 m3/g. The CO2 adsorption process was studied under different operating conditions, temperature between 298 and 328 K and pressure between 2 and 10 bar. WSHC adsorbent has the maximum CO2 uptake with a value of 11.053 mmol/g at 298 K and 10 bar. The behavior of the adsorption process was investigated using isotherm, kinetic, and thermodynamic models. Experimental findings indicated that the Sips isotherm and the second‐order kinetic models provided the best fit. The isotherm data indicated that adsorption occurs in multi‐layers and is heterogeneous. According to the thermodynamic characteristics, the process is exothermic and spontaneous. Finally, the kinetic findings established that the process happened physically. Additionally, a regeneration study after seven cycles revealed a 96.1% success rate. The current research may attempt to use waste Styrofoam as a gas separation adsorbent in the industry.