Equipment configuration case studies

Figure 1. Apparatus for slurry-scale electrochemical experiments with [Si(Pc)0]Xy n materials. ln the case shown, the equipment is configured for studies in acetonitrile/(n-Bu)4-N+BF4.

A new type of configuration, the flowing liquid membrane (FLM) was studied by Teramoto et al. [20]. In this case, the membrane liquid phase is in motion as the feed and strip phase. In this type of system a plate-and-frame and spiral-wound configuration with flat membrane was used. The scheme of the FLM configuration is drawn in Fig. 7.3A. The hquid phase flows (FLM) between two hydrophobic microporous membranes. The two membranes separate the hquid membrane phase from feed and strip phases. In Fig. 7.3B, it is reported the classical plate-and-frame module employed for the separation of ethylene from ethane [20]. The liquid membrane convection increased the membrane transport coefficient in gas separation. However, the membrane surface packing density (membrane surface area/ equipment volume) is much lower in spiral-wound system than in hollow fiber. 

The use of a sample holder requires the sample to be reduced to a fine powder. This condition is not a problem when determining, for example, the structure of a new phase that has just been synthesized and this type of equipment is used for that purpose by solid state chemists. However, it is sometimes necessary to directly study bulk samples for which grinding could cause phase transitions. In those cases, the sample is a plane object that can be studied with the same diffractometer. Different configurations are then possible, with different paths for diffracted beams and different angular resolutions depending on the relative positions of the various elements included in the apparatus. 

The reactor configuration is so important because it determines the rates of the physical transport phenomena that accompany the chemical reaction, which in their turn determine to a great extent the outcome of the chemical operation. It is also very important to note that in most cases the essential features of the reactor configuration can be studied in volumes on the order of 1 cm, since such a volume will as a rule contain several particles, drops or bubbles. Also reactions in parallel gas/liquid-flow can be studied on a very small scale. This means that the effects of the configuration on the selectivity can be studied in small scale laboratory equipment. 

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