Project Update: Incorporating CFD in the CFP Development Process

Project Update:  Incorporating CFD in the CFP Development Process

 

John Pendergrass, Peter Blaser and Travis Carver, CPFD Software

Bruce D Adkins and Neeti Kapur, KiOR

 

Keywords:  fluidization, scale-up, CFD, catalytic fast pyrolysis

Scale-up of fluidization processes is challenging, time-consuming and often counter-intuitive.  KiOR's proprietary Catalytic Fast Pyrolysis (CFP) process was developed and commercialized using a traditional scale-up approach utilizing multiple reactor scales and established engineering scale-up principles.  The flow of catalyst concepts, reactor ideas and process designs has historically been fairly linear:

This historical scale-up process has been resource-intensive.  In the past 6 years there have been approximately 8,000 individual tests in 3 different PRUs, 37,000 hours on stream in 2 different KCRs and 18,000 hours on stream in the demonstration unit. 

Recently, KiOR has added Computational Fluid Dynamics (CFD) technology to their development process.  Modeling of gas particle fluidization is performed using the commercial Barracuda Virtual ReactorŽ software, enabling simulation of particle loadings ranging from dilute to close-pack while, at the same time, including the full particle size distributions of multiple particle materials. 

This presentation provides a status update on the incorporation of CFD in the CFP development process.  The experimental and operational data from various scales is being used to validate and inform the computational models which, in turn, inform the scale-up process.  Sample results are shown from three critical sub-projects:

1.       Catalyst circulation:  Catalyst circulation and hold-up is studied using a Circulating Fluidized Bed (CFB) for a wide range of catalyst-to-feed ratios, both experimentally and numerically.

 

2.       Biomass-catalyst mixing:  Biomass-catalyst mixing is studied across a wide range of fluidized bed operational densities, further verifying the applicability of the CFD results for the wide range of operating conditions possible at commercial scale.   

3.       Reaction kinetics and heat of reaction:  To date the CFD for this system has been primarily applied to hydrodynamics only.  Work done toward extending the validation of the models to thermal and reacting systems is presented.