Research Progress on Microreactor Technology in oxidation reactions

: In recent years, the development of the chemical industry has been moving in a green, safe and efficient direction. Oxidation reactions are one of the most important types of reaction, and have key applications in food, medicine, and cosmetics, petrochemicals. However, the occurrence of the oxidation reaction is accompanied by a strong exothermic phenomenon, and improper control can easily lead to safety problems and even explosions. The realization of an environmentally friendly oxidation reaction is a key industrial milestone. The unique structural characteristics of microreactors result in good mass and heat transfer performance, precise control of the reaction temperature, reduced risk of explosion, improved safety production and selectivity of products. These unique advantages of the microreactor determine its significant application value in oxidation reactions. In this paper, the research progress of several typical oxidation reactions including alkane oxidation, alcohol oxidation, aldosterone oxidation, aromatics oxidation and olefin oxidation combined with microreactors is reviewed systematically.

Recent developments in microreactor technology for biocatalysis applications

Through the use of microfluidics technology, one can severely accelerate the development and optimization of biocatalytic processes. In this work, the authors present a comprehensive review of the recent advances in the field.

Characterization of the Mixing Performance of an Innovative Hepatic Sinusoids-Based Microreactor Using Villermaux-Dushman Protocol

Microreactor technology has drawn attention in many industrial applications, especially those that requires the use of low flow rates whereas the flow is considered to be stratified. At such low flow rates, the reactor performance is usually down especially if mass transfer occurs mainly by diffusion. In the present work, the mixing performance of a novel hepatic sinusoids-based microreactor has been investigated using Villermaux–Dushman protocol. The protocol is an iodide/iodate chemical test reaction that relies on testing the absorbance of the product at 352 nm as an indication of the formation of triiodide. The investigation is carried out at low flow rates ranges from 0.5 to 3 ml/min. The novel microreactor has proven to give satisfactory performance and is easy to be fabricated as it consists of a single layer. The absorbance of light ranges between 0.29 to 0.48 resulting on the creation of limited amount of triiodide ions. It is also noticed that the mixing performance of the reactor is nearly the same over the whole studied range of flow rate. The mixing quality is also determined using another system containing 200 ppm congo red aqueous solution and pure distilled water. About 94% to 96% mixing quality is achieved.

A Hepatic Sinusoids-Based Microreactor for Photocatalytic Degradation of Methylene Blue by Titanium Dioxide

Microreactor technology is considered a state of art technology that gained great attention from researchers due to the high effectiveness and the small residence time compared with other regular reactors. Great research work has been established to involve microreators in a variety of applications, including fuel production, food and chemical industries, medical applications. In the present study, a hepatic sinusoids-based microreactor is experimentally tested in Methylene blue degradation using titanium dioxide (TiO2) photocatalyst activated with ultraviolet lamp of wavelength 365 nm. Purification of water using photocatalysis is considered a promising technology that attract the industrial community. Different operating conditions are investigated including; flow rate, Methylene blue concentration, and TiO2 concentration. 3 different dye concentrations are used (10 ppm, 20 ppm, and 30 ppm) with 3 different photocatalyst concentrations (100 ppm, 300 ppm, and 500 ppm). The flow rate has a span from 0.25 ml/min to 1 ml/min. Experiments are conducted to determine best operating conditions. Results show that the microreactor system can be effectively used in dye degradation with a very small residence time. A degradation of over 95% was reached at a TiO2 concentration of 300 ppm and a flow rate of 0.25 ml/min for all tested dye concentrations.

Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow

The first example of photocatalytic trifluoromethoxylation of arenes and heteroarenes under continuous-flow conditions is described. Application of continuous-flow microreactor technology allowed to reduce the residence time up to 16 times in comparison to the batch procedure, while achieving similar or higher yields. In addition, the use of inorganic bases was demonstrated to increase the reaction yield under batch conditions.