Oscillatory baffled reactor

Fig. 1.3 S mall scale oscillatory baffled reactor (OBR) for gram scale suspension polymerization.

X-W. Ni, From maximum to most efficient production using a continuous oscillatory baffled reactor, http //www.nitechsolutions.co. 

Formulation of multi-component emulsions and mixtures are of interest in chemical and industrial processes (Vilar, 2008 Vilar et al., 2008). Standard stirred tank reactors (STR) and oscillatory baffled reactors (OBR) are traditional methods for the formulation of liquid-liquid mixtures and liquid-solid emulsions. Compared with STR, oscillatory baffled reactors provide more homogeneous conditions and uniform mixing with a relatively lower shear rate (Gaidhani et al., 2005 Harrison and Mackley, 1992 Ni et al., 2000). Figure 17 is a sketch of a typical oscillatory baffled reactor. It consists of the reactor vessel, orifice plate baffles, and an oscillatory movement part. The orifice plate baffles play an important role in the OBR for the vertex generation in the flow vessels as well as the radial velocities of the emulsions and mixtures. They are equally spaced in the vessel with a free area in the center of each baffle... 

Figure 17 Sketch of the oscillatory baffled reactor (top) and flow within baffled sections (bottom).

Figure 18 Tomographic images of local oil fraction distributions in oscillatory baffled reactor (top left), with estimated velocity profiles (top right) from crosscorrelation signals between adjacent electrode rings (bottom right) and vector map (bottom left) (Vilar et al, 2008 Vilar, 2008) (see Plate 15 in Color Plate Section at the end of this book).

Vilar, G., On-line measurement of dispersions in an oscillatory baffled reactor using electrical impedance tomography, PhD Thesis, University of Leeds, Leeds UK (2008). 

Visualization of dispersions in an oscillatory baffled reactor, ERT applications in, 207-209 Visualization of multi-phase fluids through sudden expansions, PET applications in, 214 V-mixer, 163... 

The concept of process intensification aims to achieve enhancement in transport rates by orders of magnitude to develop multifunctional modules with a view to provide manufacturing flexibility in process plants. In recent years, advancement in the field of reactor technology has seen the development of catalytic plate reactors, oscillatory baffled reactors, microreactors, membrane reactors, and trickle-bed reactors. One such reactor that is truly multifunctional in characteristics is the spinning disk reactor (SDR). This reactor has the potential to provide reactions, separations, and good heat transfer characteristics. 

Harvey, A. (2013) Green Chemistry in Oscillatory Baffled Reactors in Process Intensification for Green Chemistry, Engineering Solutions for Sustainable Chemical Engineering, (eds K. Boodhoo, and A. Harvey), John WUey Sons. Chichester pp. 157-172. 

Figure 10.17 Basic scheme of an oscillatory baffled reactor heated by solar thermal energy over an energy storage tank...

Solano, J.P., Herrero, R., Espin, S. et al. (2012) Numerical study of the flow pattern and heat transfer enhancement in oscillatory baffled reactors with helical coil inserts. Chemical Engineering Research and Design, 90,732-742. 

Phan, A. N., Harvey, A. P., Rawchffe, M. (2011). Continuous screening of base-catalysed biodiesel production using new designs of mesoscale oscillatory baffled reactors. Fuel Processing Technology, 92, 1560—1567. 

A Study of a Phase Transfer Catalytic Reaction between N>Butyl Bromide and Sodium Phenolate in an Oscillatory Baffled Reactor... 

Tubular reactor Inverse suspension polymerization of acrylamide in a batch oscillatory baffled reactor 1 m in length, with a diameter of 5 cm) up to 9 baffles oscillate with a frequency between 1 and 5 Hz 178... 

The oscillatory baffled reactor (OBR), illustrated in Figure 5.13, is a novel form of continuous plug flow reactor, in which tubes fitted with equally-spaced, low-constriction orifice plate baffles have an oscillatory motion (range 0.5 to 10 Hz) superimposed upon the net flow of the process fluid. 

Figure 5.14 Typical mixing patterns in an oscillatory baffled reactor.

Figure 5.15 Residence time distributions of oscillatory baffled reactors.

Figure 5.19 Comparison of Nu versus Re for smooth-walled tubes and oscillatory baffled reactors at varying Re, (Mackley and Stonestreet, 1995).

Figure 5.20 Mixing based design methodoiogy for continuous oscillatory baffled reactors (Harvey and Stonestreet, 2002).

Intensification of a Batch Saponification Process by Conversion to Continuous Processing in an Oscillatory Baffled Reactor (OBR)... 

Harvey, A.P. and Mackley, M.R. (2002). Intensification of two-phase liquid batch reactions using continuous oscillatory baffled reactors. AIChE Annual Meeting, Indianapolis, USA, November. 

Harvey, A.P. and Stonestreet, P. (2002). A mixing-based design methodology for continuous oscillatory baffled reactors. Chem. Eng. Res. Des., Vol. 80, pp. 31-44. 

Harvey, A.P, Mackley, M.R. and Seliger, T. (2003). Process intensification of biodiesel production using a continuous oscillatory baffled reactor. J. Chem. Technol. and BiotechnoL, Vol. 78, pp. 338-341. 

Ni, X., Bennett, D.C., Symes, K.C. and Grey, B.D. (2000a). Inverse phase suspension polymerization of acrylamide in a batch oscillatory baffled reactor. J. Appl. Polym. ScL, Vol. 76, pp. 1669-1676. 

Ni, X., Zhang, Y. and Mustafa, I. (1998). An investigation of droplet size and size distribution in methylmethacrylate suspensions in a batch oscillatory baffled reactor. Chem. Eng. ScL, Vol. 53, pp. 2903-2919. 

The chapter on mixers is comparatively short - not because mixers are unimportant, but because mixing is such an integral part of other intensive processes (heat exchange, reactions and crystallisation/precipitation as examples), that the topic is addressed continuously through other equipment and application chapters. The point is well made by Wu et al. (2(X)7) who stresses in their recent review that PI needs to be implemented via increased mixing, as well as heat and mass transfer - hence the success in this area of the spinning disc and the oscillatory baffle reactors. 

The chemicals (bulk, fine and pharmaceutical) and offshore industrial sectors are not the sole preserves of process intensification, as has already been illustrated in this book. In this chapter the reader is introduced to other process industry sectors where PI has made significant inroads into unit operations. Some sectors adopted intensification techniques in advance of the chemical industry (e.g. nuclear reprocessing), others pioneered techniques, such as ultrasonics, decades before they became accepted in areas such as chemical reaction intensification (e.g. in metallurgy). The food sector uses microwaves routinely for speeding up cooking processes, and effluent treatment can benefit from oscillatory baffle reactors. Aerospace, although perhaps not regarded as a process industry, is also included in this chapter. 

---