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This study investigates the effect of synthesis and operating parameters on the adsorption of CO2 and N2 and the CO2/N2 selectivity of a hypercrosslinked adsorbent based on waste-expanded polystyrene. Six factors were examined, including synthesis time, crosslinker and catalyst amounts, adsorption temperature and pressure, and CO2 percentage in the mixture. The response surface methodology (RSM) and ideal adsorbed solution theory (IAST) were employed to design the experiment. After synthesizing 19 adsorbents under different conditions, characterization tests were conducted. Results indicate that the specific surface area and micropore volume initially increase and then decrease with increased synthesis time, crosslinker, and catalyst amounts. The highest specific surface area and micropore volume were 803.84 m2/g and 0.1355 cm3/g, respectively. CO2/N2 selectivity and the adsorption of CO2 and N2 also increase and decrease with increased synthesis parameters. Furthermore, it was observed that CO2 adsorption and CO2/N2 selectivity increased with an increase in pressure and CO2 percentage and a decrease in temperature, while N2 adsorption decreased. The adsorbents were optimized using RSM to maximize CO2 adsorption and CO2/N2 selectivity with a target of 15 % CO2 in the gas mixture. The optimal synthesis parameters for the hypercrosslinked adsorbent, including synthesis time, crosslinker, and catalyst amounts, were determined to be approximately 13 hours, 30 mmol, and 30 mmol, respectively. Under optimal conditions for flue gas applications (CO2:N2/15:85), the adsorbent demonstrated a CO2/N2 selectivity of 11.05, making it suitable for flue gas capture.

This study investigates the effect of synthesis and operating parameters on the adsorption of CO 2 and N 2 and the CO 2 /N 2 selectivity of a hypercrosslinked adsorbent based on waste-expanded polystyrene. Six factors were examined, including synthesis time, crosslinker and catalyst amounts, adsorption temperature and pressure, and CO 2 percentage in the mixture. The response surface methodology (RSM) and ideal adsorbed solution theory (IAST) were employed to design the experiment. After synthesizing 19 adsorbents under different conditions, characterization tests were conducted. Results indicate that the specific surface area and micropore volume initially increase and then decrease with increased synthesis time, crosslinker, and catalyst amounts. The highest specific surface area and micropore volume were 803.84 m2/g and 0.1355 cm3/g, respectively. CO 2 /N 2 selectivity and the adsorption of CO 2 and N 2 also increase and decrease with increased synthesis parameters. Furthermore, it was observed that CO 2 adsorption and CO 2 /N 2 selectivity increased with an increase in pressure and CO 2 percentage and a decrease in temperature, while N 2 adsorption decreased. The adsorbents were optimized using RSM to maximize CO 2 adsorption and CO 2 /N 2 selectivity with a target of 15 % CO 2 in the gas mixture. The optimal synthesis parameters for the hypercrosslinked adsorbent, including synthesis time, crosslinker, and catalyst amounts, were determined to be approximately 13 hours, 30 mmol, and 30 mmol, respectively. Under optimal conditions for flue gas applications (CO 2 :N 2 /15:85), the adsorbent demonstrated a CO 2 /N 2 selectivity of 11.05, making it suitable for flue gas capture. • Various hyper-cross-linked polymers were developed from waste polystyrene for CO 2 /N 2 uptake. • IAST coupled RSM technique was employed to model and optimize CO 2 /N 2 adsorption. • Tuning HCP's morphology during synthesis yielded enhanced CO 2 /N 2 adsorption selectivity. • Isotherm and kinetic modeling exhibited physically CO 2 /N 2 adsorption mechanism. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the preparation and characterization of heterogeneous membranes based on microparticle hypercrosslinked polymeric adsorbents with a polyimide binder. The polyimide based membrane extension is hindered by their low permeability. We enhanced the permeability of polyimide membranes by changed chemical structure and by adding of the new type fillers. Hypercrosslinked polystyrene microparticles of diameter 1–5μm were prepared by SnCl4-catalyzed Friedel–Crafts reaction of polystyrene with chloromethyl methyl ether in 1,2-dichlorethane solution. The precursor polyamic acid (PAA) was synthesized by the reaction of equimolar amounts of 4,4′-oxy(bis(phthalic anhydride)) (ODPA) and bis(4,4′-oxydianiline) (ODA) or 4,4′-[(1,4-phenylene)dipropane-2,2-diyl]dianiline (BIS P) in N-methylpyrrolidone (content 10wt.%). A PAA solution in N-methylpyrrolidone with the adsorbent was spread onto a glass substrate and kept at 60–240°C for 12h. Heterogeneous membranes were characterized by thermal, mechanical and separation measurements. The permeability for membrane ODPA–BIS P filled with 10wt.% of hypercrosslinked adsorbent was 3.5×10−11 cm3(STP)cmcm−2 s−1 cmHg−1 for nitrogen and 4×10−9 cm3(STP)cmcm−2 s−1 cmHg−1 for hydrogen. The permeability of homogeneous polyimide membranes is up to one order of magnitude lower. The diffusion coefficient of heterogeneous membranes increased in the order CH4

Abstract: Synthesis of hypercrosslinked microparticles is described and the effect of reaction conditions on adsorbent properties is discussed. Heterogeneous membranes based on hypercrosslinked microparticle adsorbent with a poly(phenylene oxide) binder were prepared and tested for separation of hydrogen from a isobutane/hydrogen mixture. The separation process was characterized by parameters, such as diffusion flux, permeability, and selectivity. The prepared membranes were superior to the homogeneous ones in permeability and to zeolite-filled membranes in selectivity. Selectivity reached values of about 540 in H2/isobutane separation. [Copyright &y& Elsevier]

Abstract: In this paper a new bifunctional polymeric resin (LS-2) was synthesized by introducing sulfonic groups onto the surface of the resin during the post-crossing of chloromethyl low crosslinking macroporous poly-styrene resin, and the comparison of the adsorption properties of LS-2 with Amberlite XAD-4 toward aniline and 4-methylaniline in aqueous solutions was made. The study focuses on the static equilibrium adsorption behaviors, the adsorption thermodynamics, and the column dynamic adsorption and desorption profiles. Freundlich model gives a perfect fitting to the isotherm data. Although the specific surface area of LS-2 is lower than that of Amberlite XAD-4, the adsorbing capacities for these two adsorbates on LS-2 are higher than those on Amberlite XAD-4 within the temperature range 288–318K, which is contributed to microporous structure and the polar groups on the network of LS-2 resins. The adsorption for aniline or 4-methylaniline on LS-2 was proved to be an endothermic process and increasing temperature was favorable. From the studies on the adsorption thermodynamics, static equilibrium adsorption, and the desorption conditions, an important conclusion can be drawn that the adsorption for aniline or 4-methylaniline on the LS-2 is a coexistence process of physical adsorption and chemical transition. [Copyright &y& Elsevier]