Modelling of phenol biocatalytic oxidation tubular reactor

The oxidation of organic substrates to obtain popular products is an important part of modern chemistry and chemical technology. 1,4-benzoquinone is widely used for the preparation of dyes, pharmaceutical substances, and also as an intermediate product in basic chemical synthesis. Traditionally, 1,4-benzoquinone is synthesized by the oxidation of aniline with strong oxidizing agents, which is not very environmentally friendly and requires additional purification of the final product. The use of enzyme-containing catalysts can significantly improve the environmental performance of this process. As an enzyme, it is possible to use oxidoreductases of various structures, including peroxidases that catalyze the oxidation of organic substrates with hydrogen peroxide. Currently, a large number of works are devoted to the problem of enzymatic oxidation of organic substrates, but the issue of their use in large-volume reactors has not been considered in sufficient detail, and therefore modeling of such systems is an actuarial task of modern chemistry and chemical technology. The article presents the results of modeling a flow reactor for the oxidation of phenol with hydrogen peroxide to produce 1,4-benzoquinone. The simulation was carried out in the COMSOL Multiphysics 5.3 environment, taking into account the kinetic patterns of phenol oxidation, substance transfer processes, as well as thermal processes occurring inside the reactor. The possibility of achieving a yield of 1,4-benzoquinone of 94% with a reactor reaction zone length of 4 m has been shown; an increase in the diameter of the reaction zone from 0.05 to 0.15 m leads to a decrease in the yield of the target product to 50%, and an increase in the temperature of the heating wall from 30℃ to 40℃ leads to a 15% increase in yield. An increase in the initial concentration of phenol from 0.1 mol/L to 0.8 mol/L leads to a decrease in the yield of the reaction product 1,4-benzoquinone from 94% to 50%. This shows the need to add additional reaction zones if it is necessary to use concentrated solutions.