Multiphase reactors operating conditions pressure

Reactions between components of a gas and a liquid, the kinetics of which were discussed in Chapter 6, are carried out in a variet> of equipment, often having confusing names. The variety stems from a number of conditions that have to be fulfilled simultaneously efficient contact between gas and liquid—and eventually a solid catalyst, limitation of pressure drop, ease of removal of heat, low cost of construction and operation. Depending on whether the main mass transfer resistance is located in the gas or in the liquid, multiphase reactors or absorbers are operated either with a distributed gas phase and continuous liquid phase or vice versa. Whether co- or countercurrent flow of gas and liquid is used depends on the availability of driving forces for mass and heat transfer and reaction. 

The process has been briefly described by Turunen (1997) as an example of process intensification activities. Most of the hydrogen peroxide production is nowadays based on the anthraquinone method. The differences between the technologies include mainly differences in solvents, catalysts and equipment types and details. The process has less than ten main unit operations including two multiphase reactors, liquid-liquid extraction, gas desorption, distillation and filtration. The process conditions do not include high temperatures or pressures. The necessary properties are not readily available from literature because of the large number of components in the process liquid. However, the measurement of the most of the properties is relatively easy because of the mild conditions. The number of components which take part in the main production reactions and separation steps is small. Therefore it was possible to develop reliable models for most of the unit operations and to base the design on these nnodels. However, the side reactions and by-products involve complicated chemistry and... 

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