Modeling of enzymatic conversion in the catalytic gel layer located on a membrane surface

Equations describing a multi-phase bioreactor with a catalytic membrane located on the boundary of phases, of which one is a substrate reservoir, were formulated. A model analysis of the process was carried out and the effect of main operating parameters of such a reactor, i.e., the catalytic layer thickness and the coefficients of diffusion mass transport in both phases, was determined. Two periods with different methods of supplying the catalytic layer can be distinguished in the process. There is also a characteristic thickness of the catalyst layer: when it is exceeded, the process duration is no longer shortened although full substrate conversion from the supply stream not always has a place. It is recommended to apply thin layers because then the catalyst activity is fully used. The analyses of the influence of mass transfer showed that substrate mass transfer in the water phase to the catalyst layer has a slight effect on the process rate when the intensification of its transfer in the organic phase might have a significant influence on the process rate.

As a result of model analysis of the process that takes place in a multi-phase reactor with a catalytic membrane located at the boundary of phases, it was found that: 1. Two periods with different methods of supplying the catalytic layer can be distinguished in the process. In the first period, substrate is supplied to the layer only from its reservoir (organic phase), while in the second one from both phases that surround it. 2. There is a characteristic thickness of the catalyst layer — when it is exceeded, the process duration is no longer shortened. It is recommended to apply thin layers because then the catalyst activity is fully used. 3. The process of substrate mass transport by diffusion from its reservoir to the catalyst layer should be intensified, but there is some boundary value of transfer coefficient k1, which when exceeded, does not cause an increase of the process rate. 4. Transport of substrate mass from the water phase to the catalyst layer has a slight effect on the process rate and there is no need to intensify it.