engleski

Alcohol dehydrogenase catalyzed hexanol oxidation in a microreactor

The miniaturization of today’s reactor systems offers many advantages and opens new research fields in chemistry, molecular biology, biotechnology and pharmaceutical chemistry. High surface to volume ratio, small amounts of chemicals, laminar flow, high heat and mass transfer rates and short residence time makes this new reaction system highly interesting. Microreactors, in general, are defined as miniaturized reaction systems which are at least partially fabricated by use of methods of microtechnology and precision engineering (Löwe and Ehrfeld, 1999). In the simplest form, microreactor devices consist of a network of micron-sized (typical dimensions are in the range 10 – 500 µm) channels etched to the solid frame. These reactor systems are proposed for various applications such as ; small scale production of hydrogen for fuel cells, kinetic studies, catalyst screening and fine chemicals synthesis. Wide range of single- and multi-phase reactions have been performed in microreactors. Due to the small dimensions, chemical processes in microreactors can be different from these in macro-scale processes. Secondary phenomena (i.e. mass diffusion, surface conditions and heat conduction) become significant in microreactor when characteristic length decreases (Schuster et al., 2008). The catalytic oxidation of alcohols to aldehydes is of great importance for manufacture of fragrances and food additives as well as of many synthetic intermediates in organic synthesis (Sheldon and Kochi, 1981). Aim of this work was to investigate and compare biocatalytic hexanol oxidation catalyzed by commercial alcohol dehydrogenase in batch reactor and microreactor. Mathematical model of the hexanol oxidation catalyzed by alcohol dehydrogenase was developed to better understand complex process taking place in microreactor system. Model was composed of convection, diffusion and enzyme catalyzed reaction terms. Enzyme kinetics was described with double substrate Michaelis-Menten expressions with competitive inhibition (Vrsalović Presečki, 2006).

microreactor; hexanol oxidation; alcohol dehydrogenase; mathematical modeling

Ovaj se tekst temelji na radu koji je financirala Nacionalna zaklada za znanost, visoko školstvo i tehnologijski razvoj Republike Hrvatske.