The characteristic of competitive adsorption of HCHO and C 6 H 6 on activated carbon by molecular simulation

ABSTRACTTo explore the characteristic of competitive adsorption of formaldehyde (HCHO) and benzene(C6H6) on activated carbon, the slit models of activated carbon with different pore sizes of 1 nm, 2 nm and 4 nm were constructed by using the Visualizer module of Materials Studio molecular simulation software. The adsorption of single-component C6H6 and HCHO at three different temperatures of 288.15K,293.15K and 323.15K were conducted by the method of grand canonical Monte Carlo. Experiments were carried out to verify the accuracy of simulation results. For the single-compound adsorption, the adsorption amount of C6H6 varied little at different temperature conditions, while the pore size had a significant effect on the adsorption amount of C6H6, and the adsorption capability increased as the pore size goes up. The adsorption capacity of HCHO decreased as the temperature goes up, and the adsorption capacity of both 1 nm and 4 nm pore size activated carbon was less than that of 2 nm pore size. As for the competitive adsorption, HCHO has a better adsorption effect by activated carbon when the pore is in small size like 1 nm, while the competitive adsorption ability of C6H6 is much better than HCHO as the pore size goes up to 2 nm or 4 nm.Implications: (1) Understanding the equilibrium process of activated carbon adsorption at the molecular level based on the co-existence of multi-component VOCs. (2) The effects of concentration, temperature and humidity factors on the coupling of the dynamic equilibrium of competing adsorption of benzene and formaldehyde were analyzed. (3) The accuracy of the molecular simulations was verified using an experimental approach Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementThe authors confirm that the data supporting the findings of this study are available within the article.Additional informationFundingThe work presented in this paper is supported by the Natural Science Foundation of China through grant [No. 52278121].Notes on contributorsZhiqiang WangZhiqiang Wang is an Associate Professor at Tianjin University of Commerce in China and his main research interests are building ventilation and air quality.Zhaoyang LiuZhaoyang Liu is a master's student at Tianjin University of Commerce, China, and his main research interests are activated carbon adsorptionand air quality control.Bo WangBo Wang is a master's student at Tianjin University of Commerce, China, and his main research interests are activated carbon adsorption of VOCs.Jingjing PeiJingjing Pei is an Associate Professor at Tianjin University in China, with a focus on comfort buildings and purification of air pollutants from industrial buildings.