Pertraction-adsorption in situ product removal system: design and mathematical modeling

Abstract

Bioproduction of 2-phenylethanol is strongly influenced by inhibition, which affects its productivity. In such cases, in situ product removal is applied to enhance the production. This work is devoted to the design of a pertraction-adsorption product removal system for 2-phenylethanol separation during its bioproduction. Separation performance of pertraction was tested in experiments with two differently sized membrane modules. Results showed that the supported liquid membrane created by octane is impermeable for L-phenylalanine, which is the precursor of biotransformation. Closed loop fixed bed adsorption experiments showed that increasing the volumetric flow rate through the column shortened the time needed for adsorbent saturation. Removal rate of 2-phenylethanol in a pertraction-adsorption product removal system is thus dependent on the membrane area as well as on the amount of adsorbent used. Most of the transported 2-phenylethanol was accumulated on the adsorbent surface at the end of experiments. Potential application of a pertraction-adsorption removal system was tested in experiments with simulated 2-phenylethanol production, where the reduction of 2-phenylethanol aqueous concentration would result in more intensive bioproduction because product inhibition was avoided. Mathematical models of pertraction, adsorption and pertraction-adsorption removal system agreed well with the experimental results reaching the coefficients of determination close to one.