Chemical Engineering and Catalysis

Biography

Biography: Niels Michiel Moed

Abstract

Adsorption of isopropyl alcohol (IPA) on activated carbon was tested in both batch and fixed bed adsorption. In the batch systems the influence of solution pH, IPA concentration and stirring speed were tested. A solution pH of 7.27 was optimal for IPA adsorption on activated carbon, which was close to the pH_pzc of the activated carbon. The adsorption capacity of activated carbon was higher and the removal efficiency was lower for experiments conducted with higher IPA concentrations. Adsorption kinetics using the pseudo-first order, pseudo-second order and double exponential models showed the pseudo-first order model was most accurate, closely followed by the double exponential model. The intra-particle model showed that IPA adsorption consisted of into three stages; the film diffusion stage, the intra-particle diffusion stage, and finally the equilibrium stage. The intra-particle diffusion stage was the rate-limiting step. In modeling of the steady-state data, the Langmuir isotherm model showed a better fit than the Freundlich isotherm model. Fixed-bed adsorption experiments revealed the influence of IPA concentration and volumetric flow rate. Again adsorption capacity was higher and saturation (both the breakthrough point and saturation point) happened faster for experiments conducted with higher concentrations. Higher volumetric flow rates led to both lower adsorption capacity and faster saturation, likely due to a shorter contact time. In modeling for fixed-bed adsorption the Thomas model and Yoon-Nelson model successfully described the whole process, the Adams-Bohart model was only accurate in describing the initial adsorption part.