Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, China; Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry, Beijing Technology and Business University, Beijing 100048, China.
College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
J Hazard Mater. 2020 Jun 15;392:122323. doi: 10.1016/j.jhazmat.2020.122323. Epub 2020 Feb 15.
A considerable amount of volatile organic compounds (VOCs) is emitted, and a vast amount of citric acid residue (CAR) waste is simultaneously produced during citric acid production. Thus, a suitable method realizing the clean production of citric acid must be developed. This study investigated the adsorption of the multicomponent VOCs in a homemade CAR waste-based activated carbon (CAR-AC). A fixed-bed experimental setup was used to explore the adsorption and desorption of single- and multi-component VOCs. Surface adsorption and diffusion molecular models with different defects were built to study the underlying adsorption and diffusion mechanisms of multicomponent VOCs on CAR-AC. The adsorption amount of ethyl acetate in CAR-AC from multicomponent VOCs was 3.04 and 5.91 times higher than those of acetone and acetaldehyde, respectively, and the interaction energy between ethyl acetate and C surfaces was low at -13.41 kcal/mol. During desorption, the most weakly adsorbed acetaldehyde desorbed from the surface of CAR-AC first, followed by acetone and ethyl acetate. The regeneration efficiencies of acetaldehyde, acetone, and ethyl acetate reached 88.77, 85.55, and 91.46 %, respectively, after four adsorption/desorption cycles. We aimed to provide a new strategy to realize the recycle use of CAR and the clean production of citric acid.
柠檬酸生产过程中会排放大量挥发性有机化合物（VOCs），同时会产生大量柠檬酸残渣（CAR）废物。因此，必须开发一种合适的方法来实现柠檬酸的清洁生产。本研究考察了自制 CAR 废物基活性炭（CAR-AC）对多组分 VOCs 的吸附作用。采用固定床实验装置研究了单组分和多组分 VOCs 的吸附和解吸。建立了具有不同缺陷的表面吸附和扩散分子模型，以研究多组分 VOCs 在 CAR-AC 上的吸附和扩散机理。多组分 VOCs 中乙酸乙酯在 CAR-AC 上的吸附量分别比丙酮和乙醛高 3.04 倍和 5.91 倍，且乙酸乙酯与 C 表面的相互作用能低至-13.41 kcal/mol。在解吸过程中，吸附最弱的乙醛首先从 CAR-AC 表面解吸，其次是丙酮和乙酸乙酯。经过四轮吸附/解吸循环后，乙醛、丙酮和乙酸乙酯的再生效率分别达到 88.77%、85.55%和 91.46%。我们旨在为实现 CAR 的循环利用和柠檬酸的清洁生产提供新的策略。
