Eco-engineered spherical MnO2/ZSM-5 zeolite beads for VOC removal through ozone-regenerable adsorption: Preparation, characterization, adsorption experiments and modeling

Abstract

This study develops a multifunctional zeolite-based adsorbent material with excellent performance in isopropanol (IPA) adsorption and ozone-based regeneration over multiple cycles. To enable industrial application, the material is shaped into mechanically stable beads using alginate as an organic framework and bentonite as an inorganic binder, while MnO₂ is impregnated onto the zeolite to catalyze ozone-driven regeneration. The structural characteristics and properties of the synthesized beads were analyzed using methods such as XRD, SEM, N₂ adsorption-desorption, FTIR and TGA. Through systematic investigation of calcination temperature and zeolite-to-bentonite ratio, the sample labelled Z85B15M3_450, comprising 85% zeolite, 15% bentonite, 3% MnO₂, and calcined at 450°C, demonstrated the best performance, achieving regeneration efficiency above 95% and adsorption capacity exceeding 0.7 mmol/g after each cycle. This study also incorporated adsorption modeling to examine various factors influencing the VOC adsorption process, including adsorbent mass, IPA concentration, and total gas flow rate. The BDST model was additionally applied to IPA adsorption data, demonstrating effective performance of the process at lower C/C₀ ratios.