Facilitated mass transfer in a packed‐bed immobilized‐cell reactor by using an organic solvent as substrate reservoir

Abstract

A B S T R A C TThe production of propene oxide f r o m propene and oxygen by nongrowing cells entrapped in calcium alginate was used to study the behaviour of a packed-bed immobilized-cell reactor operated with an organic solvent as the substrate reservoir. As a result of the high solubility of propene in the solvent used, n-hexadecane, oxygen was considered to be the limiting substrate. Dilution of the biocatalyst bed with small glass particles appeared necessary to attain a high liquidlsolid contacting efficiency between the hydrophilic gel particles and the hydrophobic solvent. The bed dilution had the advantage of avoiding bed compaction and reducing pressure drops. The use of an organic Solvent as the transport medium prevented oxygen depletion along the length of the packed-bed reactor. This eliminated the need for a separate gas phase in the bioreactor. A mathematical reactor model was developed to describe the combined effects of contacting pattern and external and internal diffusion limitations on the instrinsic kinetics of the immobilized cells. Experiments with the packed-bed immobilized-cell reactor were performed using an aqueous solution or n-hexadecane as the reaction medium. Predicted oxygen conversions compared favourably to the observed values without the need f o r fitting factors.

Effect of organic solvents on oxygen mass transfer in multiphase systems: Application to bioreactors in environmental protection

“…Organic solvent: hexadecane Brink and Tramper [18] Oxygen; propene Mycobacterium E3 Daugulis and Boudreau [19] Toluene Alcaligenes xylosoxidans Y234 Davidson and Daugulis [20,21] (a) Toluene, benzene A. xylosoxidans Y234 (b) Benzene Giridhar and Srivastava [22] l-Sorbose fermentation Acetobacter suboxydans Ho et al [23] Penicillin fermentations Penicillium chrysogenum Yeom et al [24] Benzene A. xylosoxidans Y234 Organic solvent: perfluorocarbon PFC40 Cesario et al [25,26] Ethane Mycobacterium parafortuitum Cesario et al [27,28] Toluene Cesario et al [29] Toluene Pseudomonas putida GJ40 Elibol and Mavituna [30] Antibiotic production Streptomyces coelicolor Menge et al [31] Alkaloid production Claviceps purpurea Takeshi et al [32] Fermentation of insect cells (Spodoptera frugiperda)…”