Batch system membrane plant

FIGURE 6.25 Configuration of a batch system membrane plant designed for microfiltration of fermentation broth. 

Pervaporation can also operate in batch mode, and this is done typically when testing membranes for small plants and for some larger multipurpose plants. Batch pervaporation systems are robust, well proven, and flexible in operation. The pumparound rate on batch systems is normally set high to give a low permeate quantity per pass. Pervaporative cooling effects are small, and such systems can be built with a single preheater and unheated modules (Fig. 3). 

In pilot plant experiments we have used a 7 m DDS-module type 40 with tight cellulose acetate membranes type DDS-990. Concentration has been performed at pH = 4.0-4.5 in a batch system at ambient temperature using 30 kp/m2 delivered by a Rannie piston pump. 

Membrane modules can be configured in various ways to produce a plant of the required separation capability. A simple batch recirculation system has already been described in cross-flow filtration. Such an arrangement is most suitable for small-scale batch operation, but larger scale plants will operate as feed and bleed or continuous single pass operation (Figure 16.20). 

Another approach to a combined system is the connection of the two systems through a quinone redox couple dissolved in an oil phase, as shown in Fig. 17.2. This system is analogous to the combination of photosystems I and II in the photosynthesis of green plants. Fig. 17.10 illustrates the structure of our model system, in which the oil-phase corresponds to the lipid bilayer membrane of chloroplast. Such a system is structurally identical to a liposome and has the possibility of development for use in a batch reactor. 

In a study on the photodegradation of lincomycin Augugliaro et al. [40] reported the use of a hybrid system consisting of a solar photoreactor with the catalyst suspended coupled with a membrane module. The photo-oxidation experiments were performed in a batch solar photoreactor at pilot plant scale by using compound parabolic collectors (CPC), installed at the Plataforma Solar of Almeria . 

Since separations are ubiquitous in chemical plants and petroleum refineries, chemical engineers must be familiar with a variety of separation methods. We will first focus on some of the most common chemical engineering separation methods flash distillation, continuous column distillation, batch distillation, absorption, stripping, and extraction. These separations all contact two phases and can be designed and analyzed as equilibrium stage processes. Several other separation methods that can also be considered equilibrium stage processes will be briefly discussed. Chapters 17 and 18 e5q)lore two inportant separations—membrane separators and adsorption processes— that do not operate as equilibrium stage systems. 

A typical batch ultrafiltration plant is represented in Figure 1. It consists of a processing tank, a feed pump, a circulation pump and a membrane unit with a number of modules in parallel. A permeate is obtained from the membranes while the retentate is recirculated until the desired concentration in the processing tank is reached. Then, a cleaning procedure is performed and the system is ready for the next batch. 

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