Study on adsorption mechanism of ethyl acetate by high alumina fly ash: modeling and experiment

This study compared and discussed the adsorption process of ethyl acetate by ordinary and high-aluminum fly ash through experiments and molecular theoretical calculations. Both ordinary and high-aluminum fly ash exhibited a gradual decrease in adsorption performance as temperature increased, with high-aluminum fly ash demonstrating superior ethyl acetate adsorption. At 298 K, the adsorption breakthrough time for ordinary and high-aluminum fly ash was 283 and 425 minutes, with saturated adsorption capacities of 13.71 and 20.22 mg/g, respectively. Density Functional Theory calculations showed adsorption energies for SiO2-ethyl acetate and Mullite-ethyl acetate to be −0.735 and −1.107 eV, respectively, indicating spontaneous adsorption of ethyl acetate by fly ash. The results of isothermal experiment and theoretical calculation show that Langmuir equation can well fit the adsorption process of FA and FA-Al on ethyl acetate. Theoretical calculations on the crack model and adsorption heat suggested that increasing temperature is not favorable for ethyl acetate adsorption by fly ash.