Adsorption performance of volatile organic compounds on activated carbon fibers in a fixed bed column

Abstract

Volatile organic compounds (VOCs) emitted from electronic industry may pose severe problems to human health and the environment. In the present study, the VOCs adsorption on commercial activated carbon fibers (ACFs) in a fixed-bed column was investigated by continuous mode as a function of inlet flow rate (100–500 L/h), inlet VOCs concentration (200–400 mg/m3), adsorption temperature (15–35 °C) and bed height (120–240 mm). Afterwards, the adsorption behavior and mechanism of VOCs on ACFs were quantified by the adsorption kinetic, equilibrium, thermodynamic models. To further quantify the adsorption performance in the fixed bed column, an axial dispersion model was proposed to model the breakthrough curves. The results indicated that the adsorption process conformed to the Langmuir isotherm and pseudo-first-order kinetic equation, indicative of physical adsorption. Moreover, the adsorption capacity increased with the increase of VOCs concentration and bed height, but decreased with the increase of inlet flow rate and adsorption temperature. Interestingly, the axial dispersion model can well predict the breakthrough curve and visualize the temporal and axial distribution of VOCs adsorption in the fixed-bed column by integrating Matlab ode15s solver with lsqcurvefit function, from which both the overall mass transfer and axial dispersion coefficient were also derived. The model herein may facilitate the process design of VOCs adsorption and precisely predict the adsorption performance of a scaled-up adsorption fixed bed.