Predictive modeling and experimental implementation of organic acids in stream recovery by reactive extraction in membrane contactors

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 431; no. part 2; p. 134067
• Main Authors: Chemarin, F., Athès, V., Buquet, W., Bedu, M., Allais, F., Teixeira, A.F., Moussa, M., Trelea, I.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2022; Elsevier
• Subjects: Chemical engineering; Chemical Sciences; Extractive bioconversion; In situ product recovery; Mass transfer modeling; Membrane contactor; Organic acids; Solvent extraction; Extractive bioconversion; Membrane contactor; Solvent extraction; In situ product recovery; Mass transfer modeling; Organic acids
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.134067

•Substantial reduction of acid accumulation with the coupled process.•Great viscosity variations due to the transfer.•Viscosity changes successfully taken into account to describe kinetics.•Model-based generalization for process guidelines. Membrane-based reactive extraction as an in situ product recovery technique is a promising strategy for process intensification, in particular in the case of the bioproduction of organic acids. Reactive extraction allows a high selectivity for the extraction of the targeted acid and the microporous membrane keeps biocatalysts in the aqueous broth while implementing a large liquid–liquid surface area and ensuring a dispersion-free contact, without problems of emulsion formation. This paper deals specifically with the extraction of biobased 3-hydroxypropionic acid using tri-n-octylamine in n-decanol. In order to maintain an effective driving force for 3-HP transfer into the organic phase, this latter was continuously regenerated by recovering the acid in a back-extraction aqueous phase, giving a complete pertraction process. A mass transfer model for this process was developed. It is based on the boundary layer theory and takes into account chemical and physical equilibria of complexation/dissociation and partitioning, species diffusion in the membrane pores and viscosity variations in the organic phase. Viscosity highly depends on acid concentration, increasing up to 50% when 3-HP concentration reaches 28 g.L-1. Thus, it was possible to predict different experimental results with R2 ≥ 0.99, totally neglecting chemical kinetics and interfacial resistance for both extraction and back-extraction steps. The model allows the prediction of extraction kinetics with (1) fixed initial concentrations and (2) with gradual 3-HP feed (mimicking a bioconversion) in transient and steady states coupled with back-extraction (globally also called pertraction). Model based analysis of mass transfer mechanisms led to the construction of a nomogram giving 3-HP stationary concentration in the case of a typical production rate, enabling for example a rapid organic phase selection or membrane sizing.