Liquid split manager

The first step is the split of the initial mixture in essentially monophase submixtures, as gas, liquid and solid. This operation, called the first separation step, can employ simple flash or a sequence of flashes, adsorption/desorption and reboiled stripping, or the combination of the above techniques. Next, the process synthesis activity can be further handled by specialized managers, namely gas split manager (GSM), liquid split manager (LSM) and solid split manager (SSM). 

The liquid split manager deals with two selectors zeotropic and azeotropic mixtures. A second decomposition may take place as a function of mixture composition and sensitivity to temperature. The first criterion generates dilute and bulk separations, while the second one leads to temperature-sensitive and temperature-... 

Thus, the overall problem can be decomposed in smaller problems, namely the synthesis of separation subsystems. This activity can be done by means of specialised managers , in this case designated by Gas Split Manager (GSM), Liquid Split Manager (LSM) and Solid Split Manager (SSM). 

The logic diagram of the Liquid Split Manager follows the pattern from the Fig. 7.18 ... 

Liquid Split Manager incorporates two split selectors zeotropic (ideal or slightly nonideal) mixtures, and azeotropic mixtures. Each selector is divided further as function of two criteria mixture composition and sensitivity to the effect of temperature. The first generates other two categories dilute and bulk separations. The second demarcates between temperature sensitive and temperature insensitive separations. 

The use of the lower flow rates employed with microbore HPLC columns or splitting of the eluate from a conventional column will immediately reduce the volume of liquid being presented to the interface and, while not necessarily totally removing the tendency to form droplets, at least is likely to make the situation more manageable. 

The Hierarchical Approach developed in this chapter incorporates a knowledge-based procedure for the synthesis of separations. This consists of dividing the separation section in three subsystems gas vapour, liquid and solid separations. Each subsystem is further managed by selectors, which makes use of unit operations. Split sequencing is based mainly on heuristics, although may include algorithmic or optimisation techniques. This chapter describe in more detail the synthesis of distillation trains for zeotropic distillations, the non-ideal case being left for the Chapter 9. 

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