Experimental Research and Analytical Modelling of a Gas-Solid Vortex Reactor (GSVR)

Experimental research and analytical modelling of a Gas-Solid Vortex Reactor (GSVR)

J. Z. Kovacevic, G. J. Heynderickx*,G. B. Marin

Laboratory for Chemical Technology, Ghent University, Krijgslaan 281 (S5) 9000 Gent, Belgium;

Tel +32 926 44 516 Fax +32 926 44 999; email: Geraldine.Heynderickx@UGent.be

Process Intensification requires the development of new reactor technologies. The Gas-Solid Vortex Reactor (GSVR) also known as the Rotating Fluidized Bed Reactor in Static Geometry (RFB-SG), provides intensification opportunities by substituting gravitational by centrifugal force. The most common limitations of operating a Static Fluidized Bed (FB) in the gravitational field are thus overcome. The high slip velocities (~1 to 10 m/s), the high solids fractions (~0.3 to 0.6), the short residence times (~50 ms), as shown by Ashcraft ^2,3, allow the GSVR to promote high throughput operations, uniform gas-solid contacting and enhanced heat and mass transfer, resulting in an intensified process on particle scale as well as on reactor scale. As an over-all result, the dimensions of the reactor can be drastically reduced. Process Intensification can be realized for different conditions: operating conditions as well as geometrical configuration.

A Fluidized Bed reactor technology in which the gravitational force field is replaced by a centrifugal force field has been considered since the seventies mainly with a rotating reactor. Extensive experimental research on the subject has not been performed, the main reason being the problematic scale-up of a rotating reactor. In the present work the centrifugal field is realized in a static reactor by a tangential introduction of the fluid phase as described in detail by Ekatpure et al ⁴. The presented study focuses on the influence of solids density, particle diameter and gas velocities on reactor hydrodynamics. 2D Particle Image Velocimetry (PIV) is used as a measuring technique to determine the particle velocities. Captured images are post processed and a particle velocity profile is obtained as shown in the added figures. At the same time the pressure profile in the rotating bed is measured using multiple pressure probes. By combining velocity and pressure profiles, the bed behaviour and influence of solids density, particle diameter and gas velocities are examined, and used to develop an analytical model for the GSVR based on the Chen⁵ partial fluidization model.

Typical 2D solids velocity profile in the GSVR based on PIV measurements

References

1.       De Wilde, J. and A. de Broqueville, Rotating fluidized beds in a static geometry: Experimental proof of concept. AIChE Journal, 2007. 53(4): p. 793-810.

2. Ashcraft, R.W., G.J. Heynderickx, and G.B. Marin, Modeling fast biomass pyrolysis in a gas–solid vortex reactor. Chemical Engineering Journal, 2012. 207–208:p. 195-208.

3. Robert W. Ashcraft, Jelena Kovacevic, Geraldine J. Heynderickx, and Guy B. Marin, et al., Assessment of a Gas–Solid Vortex Reactor for SO2/NOx Adsorption from Flue Gas. Industrial & Engineering Chemistry Research, 2013. 52(2): p. 861-875.

4. Rahul P. Ekatpure, Vaishali U. Suryawanshi, Geraldine J. Heynderickx, Axel de Broqueville, Guy B. Marin, Experimental investigation of a gas–solid rotating bed reactor with static geometry. Chemical Engineering and Processing: Process Intensification, 2011. 50(1): p. 77-84.

5. Chen, Y.M., Fundamentals of a Centrifugal Fluidized Bed  AIChE Journal, 1987. 33(5): p. 722-728.

Acknowledgment

This work was supported by the “Long Term Structural Methusalem Funding” by the Flemish government. The work was also partially supported by a European Research Council Advanced Grant, ERC-MADPII, project number 41L02311.  ADDIN EN.REFLIST