TY - JOUR ID - 84415 TI - Study on diffusion coefficient of benzene and ethyl benzene vapours in nanoporous silica aerogel and silica aerogel-activated carbon composites JO - Iranian Journal of Chemical Engineering(IJChE) JA - IJCHE LA - en SN - 1735-5397 AU - Mohammadi, A. AU - Moghaddas, J. AD - Transport Phenomena Research Center, Faculty of Chemical Engineering, Sahand University of Technology, P. O. Box: 51335-1996, Tabriz, Iran Y1 - 2019 PY - 2019 VL - 16 IS - 1 SP - 1 EP - 21 KW - Adsorption Kinetic KW - Diffusion coefficient KW - Equilibrium adsorption capacity KW - First order and second order model KW - Silica Aerogel DO - N2 - In this study, nanoporous silica aerogel and silica aerogel-activated carbon composites have been synthesized using a water glass precursor by cost effective ambient pressure drying method. Equilibrium and kinetics of benzene and ethyl benzene adsorption on silica aerogel and its composites have been measured in a batch mode at tree weights of adsorbent. For the first time, the experimental data have been fitted with intra-particle diffusion model for determining of diffusion coefficients. The saturation adsorption capacity of benzene and ethyl benzene vapours was 2033 mg.g-1 and 458 mg.g-1 respectively. The components uptake curves have been described by mathematical models of pseudo first order and pseudo second order models. It has been found that the pseudo first order model fits the experimental data better than the pseudo second order model. Also, the pseudo-second order model could be used for modeling of benzene adsorption over silica aerogel and silica aerogel-2% wt. activated carbon composite at the beginning of adsorption process. The diffusion coefficients of benzene and ethyl benzene within the silica aerogel were in the range of 〖2.16×10〗^(-14) - 〖6.66×10〗^(-13) m2.s-1 and 〖3.65×10〗^(-13) - 〖1.95×10〗^(-12) m2.s-1, respectively. UR - https://www.ijche.com/article_84415.html L1 - https://www.ijche.com/article_84415_89d422d06f557b0a6ff9a67e1b39274d.pdf ER -