Competitive Adsorption of Vanillin, Vanillic Acid, and Acetovanillone onto SP700 Resin

Abstract

In this work, the recovery of phenolic monomers obtained from the oxidative depolymerization of lignin was studied. The adsorption of aromatic aldehydes, acids, and ketones using a macroporous polymeric resin, Sepabeads SP700, was assessed experimentally. Batch experiments were performed by using aqueous model solutions for each phenolic monomer. The adsorption equilibrium for vanillin, vanillic acid, and acetovanillone in single-component and ternary mixtures was evaluated. Experimental results were regressed against the Bi-Langmuir model. The validity of a phenomenological model, comprising the adsorption equilibrium isotherm model and the linear driving force approximation for particle mass transfer, was confirmed through experimental validation using fixed bed dynamic adsorption tests. For a ternary mixture with V concentration of 4 gL-1, VA of 0.8 gL-1, and VO of 0.08 gL-1, the adsorbed amounts are 0.57 gg(dry resin)(-1), 0.05 gg(dry resin)(-1), and 0.02 gg(dry resin)(-1), respectively. This work is the first step toward the implementation of the ternary separation in a pseudo-SMB (JO-process).