ShimTec reactor

In the following part, four reactors that have been extensively studied in our lab are described the open plate reactor (OPR) - the Alfa-Laval reactor technology (ART ) plate reactor, the Shimtec reactor from Chart Industries, the Corning (glass reactor), and the DeanHex reactor which has been constructed with SiC and stainless steel. 

The ShimTec reactor from Chart Industries [18, 19] is an example of a HEX reactor with diffusion-bonded plates (Figure 12.2). The reactor is composed of three plates one process plate sandwiched between two utility plates. All the units are made of 316 stainless steel, unless stated otherwise. Swagelok fittings are used for all the connections. 

For example. Figure 12.5 shows the RTDs obtained with two different flow rates in the Shimtec reactor. Each experiment has been performed at room temperature with a total process flow rate varying from 5 to 201 h h The curves have been represented using a reduced time variable. 

Finally, the oxidation reaction has to been run under strict conditions of temperature, which are impossible to be operated in a batch reactor. Indeed, utility stream in the Shimtec reactor was heated to 47 °C, which first initiates the reaction, accelerates its kinetics, and then controls the temperature when the heat of the reaction is too important. In a batch reactor, working with such UF temperature is impossible because of security constraints. It would certainly lead to a reaction runaway. We now consider this question in the next section. 

Comparison between the heat exchanged per unit of volume during oxidation experiment in the Shimtec reactor and the maximal heat exchanged in a classical batch reactor (with a double jacket) highlights the effectiveness of the former. Indeed, in oxidation reaction experiments, a mean value of the heat exchanged per unit of volume in the HEX reactor is estimated with utility stream temperature of 47 °C ... 

Clearly, the oxidation reaction could not have been implemented in a pure batch operating reactor. Indeed, heat removal capacity would not have been sufficient (100—1200 kW m removed versus 20 x 10 kW m generated). As a consequence, a semibatch mode is necessarily required. Besides, Table 12.10 shows that the feeding times are much higher than the residence time of the Shimtec reactor (around 15 s). 

As expected, heat exchanged per unit of volume in the Shimtec reactor is better than the one in batch reactors (15-200 times higher) and operation periods are much smaller than in a semibatch reactor. These characteristics allow the implementation of exo- or endothermic reactions at extreme operating temperatures or concentrations while reducing needs in purifying and separating processes and thus in raw materials. Indeed, since supply or removal of heat is enhanced, semibatch mode or dilutions become useless and therefore, there is an increase in selectivity and yield. 

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