Bioreactors continuous reactor

Figure 11.9 Different arrangements and modes of operation for membrane bioreactors Continuous Stirred Tank Reactor (CSTR) with recirculation arrangement (a), dead-end cell (b), tubular with entrapped enzyme (c).

Bioreactors that use enzymes but not microbial cells could be regarded as fermentors in the broadest sense. Although their modes of operation are similar to those of microbial fermentors, fed-batch operation is seldom practiced for enzyme reactors. The basic equations for batch and continuous reactors for... 

Degradation constant k = 3.2-M/h for anaerobic batch experiment in serum bottles k = 2.4 -M/h for dechlorination in anaerobic batch or continuous bioreactor k = 2.4 -M/h in the sequential anaerobic-aerobic continuous reactor system (Armenante et al. 1999)... 

Eor an ideal continuous stirred-tank bioreactor (CSTB), the concentrations of the various components of the outlet stream are assumed to be the same as the concentrations in the bioreactor. Continuous operation of a bioreactor can increase the productivity of the reactor significantly by eliminating the downtime and the ease of automation. 

The above discussion may involve both control and dynamics of steady state (single and multiple), unsteady state (transition between two states) and unstable operations of the bioreactor resulting from typical non-linear response of biological systems. In spite of the fact that the stability analysis of non-linear systems is quite advanced, experimental confirmation of multiple steady states and instabilities lags behind (for a review of theory and experiments see (45)). An excellentexample of experimental demonstration of unstable operation of a continuous reactor is in (46). 

Relative to stricfly batch bioreactors, continuous and fed batch bioreactors require more connections to process stteams through which sterility must be maintained throughout the entire period the reactor is onstream. When contamination does occur in equipment used to carry out a continuous process, it can rapidly spread to downstream units. By contrast, confinement or isolation of contaminants can be accomplished more readily in a batch reactor and its associated auxiliary facilities. 

Laska ME, Cooney CL. (2002) Bioreactors, continuous stirred-tank reactors. In FUckinger MC, Drew SW, editors. Encyclopedia of Bioprocess Technology, John Wiley Sons, Inc., New York, USA. p 353-371. 

Biohydrogen photo-bioreactors have been thoroughly analysed and revised for both microalgae (Posten, 2009) and photo-fermentative bacteria (Koku et al., 2003) cultivation. For a first rough classification, photo-fermentation can be lead out in batch or in continuous reactors, with the choice being determined by feed rate and type and biomass. 

Meilleur et al. 2009), to understand the microbial diversity and activity of dye degrading microbes from a two stage anoxic-oxic continuous reactor inoculated with dye effluent (Dafale et al. 2010), and to detect novel bacterial sulfur oxygenase reductases from bioreactors treating gold-bearing concentrates (Chen et al. 2007), for example. 

Cells in suspension Plug flow reactor with hydrodynamic stirring with or without static mixing elements in tube or flat-bed bioreactor Continuous... 

Production of the vims in a bioreactor reactor, using a continuous cell line, has also been studied (85,86). This will reduce production costs and side effects. Both Madin-Darby canine kedney (MDCK) and Vero cell lines are being developed for production of the vaccine. 

The submerged culture process continues to increase in terms of the percentage of dtric acid produced compared to that produced by the surface culture method. Tower bioreactors are preferred over stirred reactors because they cost less, there is less risk of contamination and they are less limited by size. 

Batch mixed reactor There are three principal modes of bioreactor operation (a) batch (b) fed batch (c) continuous. 

The aerobic biofilter used in the study had a capacity of 10 L. The reactor was packed to 60% of the empty bed volume with Cosmo ball media. The biofilter was seeded with active innoculum taken from an active aerated lagoon of a nearby landfill leachate treatment. Fresh raw leachate was used as feed to the reactor at a rate of 5 L/d over 24h. The loading rates applied to the bioreactor were between 1.6 and 22.2 kg COD/m3d. Initial studies were conducted as a batch process lasting for a period of 24 d. Thereafter, the biofilter was fed continuously for a total period of 240 d. 

This section of the current chapter goes beyond a simple listing of current three-phase biofluidization applications to consider the differences in conventional three-phase fluidization and biofluidization from the aspect of reactor design and operation. Past research into three-phase biofluidization has been summarized in several excellent reviews (Andrews, 1988 Fan, 1989 Heijnen et al., 1989 Schiigerl, 1989 Siegel and Robinson, 1992), and this chapter will concentrate on the main research themes and advances of the last few years. Though gas continuous three-phase fluidized bioreactors exist (Fan, 1989), we consider here only those bioreactors in which the liquid phase is the continuous phase. 

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