Adsorption kinetics of volatile organic compounds (VOCs) onto super activated renewable carbon (SARC) in low-carbon composites (LCCs)

Abstract

Abstract This is the first study of adsorption kinetics of volatile organic compounds (VOCs) onto super activated renewable carbon (SARC), with the aim of maximizing the removal efficiency of odor during the compounding of low-carbon composites (LCCs). Three different micrometer-sized SARC samples were prepared by alkali (NaOH) modification of renewable carbon, named as small sized SARC (S-SARC), medium sized SARC (M-SARC) and large sized SARC (L-SARC), respectively. The morphology and geometrical properties of these prepared SARC were investigated via scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis, and their surface groups were determined by Boehm titration. Molecular dynamics (MD) simulations were applied to elucidate the migration behavior of SARC particles, with the aim of homogenizing the particles’ distribution and increasing their contact opportunities with VOCs molecules. The performance of SARC samples employed as adsorbents in LCCs had been exploited, and their adsorption capacity were evaluated by gas chromatography-mass spectroscopy (GC/MS) upon identifying and quantifying the volatile compounds. The Langmuir and Freundlich adsorption isotherms were applied, and the results revealed Freundlich was better fitting for the adsorption kinetics. The influence of various factors, e.g. chemical and physical properties of SARC, on the adsorption of VOCs were compared, and the results confirmed the dominant chemical adsorption (Freundlich Isotherm). Thus, using SARC, especially S-SARC can significantly promote the removal of odorous VOCs, and open up new horizons of full utilization of LCCs as substitutes for traditional high-carbon plastics in broader industries.