Dialysis Membrane Reactor Operation

Dialysis is among the oldest of the membrane processes, but it has found only a few industrial applications. However, greater industrial usage may 

Four basic modes are generally possible in dialysis culture operation (Fig. 6.47) (a) continuous reservoir and continuous fermenter, where and Fferm (t ) batch reservoir and batch fermenter, where F es and = 0  

Here Ati is the osmotic pressure of feed (permeate). The flux rate of the solute (salt) obeys Pick s first law, that is, 

The performance equation of a membrane can be derived by introducing intrinsic rejection (R = 1 — c lcf) and observed rejection (Robs = 1 — 0 /02) with c5 being the bulk concentration at the permeate side  

The permeability coefficient reflects the overall resistance of the composite barrier, and therefore includes external transport limitations (cf. Sect. 4.5.1), which can be quantified using the two-film theory (cf. Equ. 3.30)  

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Ultra and nanofiltration techniques based on dialysis in the reaction engineering of catalytic processes were originally developed for biotechnological applications, whereas their apphcation to organometalhc homogeneous catalysis has been a more recent development. Key contributions to the development of continuously operating membrane reactors for this type of catalytic systems are due to Kragl and others [23], while van Koten and van Leeuwen and their coworkers [24, 25] first reported the apphcation of this technique to dendrimer catalysis which led to its establishment in dendrimer chemistry. 

The influence of the OTR on kinetics (and therefore on productivity) was indicated in Equs. 5.169 and 5.170. Therefore, we will discuss here primarily those process engineering factors involved in various different types of reactors and operations. Last but not least, some unconventional reactors such as membrane (dialysis) reactors and synchronous culture techniques will be discussed. 

Different sample pretreatment operations include dilution, membrane-extraction (gas diffusion, dialysis), liquid-phase extraction techniques (liquid/liquid extraction, liquid-phase microextraction, single-drop microextraction) and solid reactors and packed columns aiming to facilitate online chemical derivatization, chromatographic separation of target species, removal of interfering matrix compounds, enzymatic assays, or determination of trace levels of analyte via sorptive preconcentration procedures (Marshall et al., 2003 Economou, 2005 Miro and Hansen, 2006 Theodoridis et al., 2007 McKelvie, 2008 Ruzicka, 2014). In this context, BIA and the LOV configurations are particularly useful. Acid-base titrations can also be automated using simple SIA manifolds and potentiometric (van Staden et al., 2002) or photometric (Kozak et al., 2011) detection. Typically, a zone of the sample to be titrated is sandwiched between two zones of titrant by aspiration. In the case of photometric detection, an additional zone of a suitable pH-sensitive colored indicator is aspirated. The stacked zones are delivered to the detector and the width of the peaks is monitored and related to the pH of the solution. 

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