Simple Methods for the Determination of Adsorption Rate and Equilibrium Parameters in the Recovery of Acetic Acid Using GAC and Synthetic Resins

Abstract

Industrial acetic acid production based on anaerobic fermentation technology is not economically viable at present due to the high cost of product recovery by adsorption or extraction at neutral pH conditions. In this study, kinetics and equilibria of acetic acid sorption onto granular activated carbon and weak base resins were examined at pH < pKa of the acid. Comparative data on equilibrium sorption from a fermentation broth are also reported. It is observed that the weak base resins have higher adsorption capacities and selectivities for the uptake of organic acids from complex mixtures compared to activated carbon. A simple method to estimate intraparticle diffusivities from batch kinetic data using approximations to analytical solutions is developed. Methods for the accurate estimation of isotherm constants and external mass transfer coefficients are discussed and implemented. The estimated coefficients are shown to predict batch kinetic data well. This study will help in the screening of sorbents fo...