Measurement and prediction of breakthrough curve of low-concentration toluene adsorbed by activated carbon

Abstract

People spend most of their time indoors. The volatile organic compounds (VOCs) in indoor air represented by toluene inevitably affect people's health. Activated carbon can effectively reduce indoor VOCs pollution. The experiments in the previous studies were carried out at the concentration of tens or hundreds of ppm, which could not reflect the actual adsorption performance of activated carbon in the actual conditions. In this study, a method was proposed to predict breakthrough curve of toluene at ~1 ppm. The method was based on Wheeler-Jonas model, the equilibrium adsorption capacity was predicted by the Freundlich equation, and the adsorption rate constant was obtained by Yoon-Nelson equation. The predicted breakthrough curves were in good agreement with the experimental data in the range of 0.5~4.0 ppm. The adsorption rate constant was predicted using the relationship with inlet concentration of toluene. When the breakout fraction was 20-85%, the relative deviation was 5.54% and 4.08% at 0.5 and 1.0 ppm. This method can predict the adsorption performance and service life of activated carbon for toluene at ppb~ppm level.