2017 Annual Meeting
(716b) Validated Hydrodynamic CFD Model for Catalytic Fast Pyrolysis
Inaeris Technologies (formerly KiOR) is a world leader in the development and commercialization of the CFP technology. Reactor design is a crucial element of the Inaeris technology. Depending on the design concept employed, it is possible to have multiple hydrodynamic regimes in the same reactor, ranging from moving bubbling bed, to dense phase riser, to dilute phase riser (fast fluidization). Furthermore, simultaneous feed of solid biomass and catalyst particles, and evolution of pyrolysis gases, complicates the hydrodynamics analysis. Both of these factors make it difficult to use standard CFB scale-up correlations and methods. As a result, Inaeris decided in late 2014 to start a program to develop computational fluid dynamics (CFD) models capable of supporting scale-up from pilot scale. Other future uses such as optimization, troubleshooting, and ultimately, blank sheet reactor design were also contemplated as a justification for this effort.
In early 2015, Inaeris selected the Barracuda Virtual Reactor® software package, and embarked on a collaboration with CPFD Software, for two reasons. The first was CPFDâs experience in rapid model development; the softwareâs incorporation of the MP-PIC numerical method was the second.
After two years, 1000+ cold flow CFB tests, and 500+ simulations, the collaboration has produced a single CFD model which has been experimentally validated for bubbling, dilute phase and dense phase regimes across a wide range of reactor configurations [1-4]. Equally important is that the model accurately predicts hydrodynamics for catalyst-only circulation, as well as those for catalyst and biomass co-feeding. This is important, because somewhere inside the reactor, the hydrodynamics transition from catalyst plus biomass to catalyst only (with some residual char particles). Thus the model must be able to accurately predict the extreme cases.
In this presentation, details of the model will be presented, and application of the model to reactor scale-up will be illustrated. Further recommendations for model refinement, as well as guidelines for general CFD model development for CFP, will also be given.
References
[1] B. Adkins, N. Kapur, J. Pendergrass, J. Parker, P. Blaser, KiOR Update: Incorporating Barracuda in our CFP Development Process, Proceedings of the Inaugural Barracuda Virtual Reactor Usersâ Conference, Santa Ana Pueblo, New Mexico, 2015.
[2] B. Adkins, N. Kapur, T. Dudley, S. Webb, P. Blaser, Experimental validation of CFD hydrodynamic models for catalytic fast pyrolysis (CFP), Fluidization XV, May 22-27, 2016, Quebec, Canada.
[3] N. Kapur, B. Adkins, T. Dudley, S. Webb, P. Blaser, âCold Flow Validation of Catalyst-Biomass Hydrodynamics in Catalytic Fast Pyrolysisâ, 2016 AIChE Annual Meeting, San Francisco, California, November 2016.
[4] B. Adkins, N. Kapur, T. Dudley, S. Webb, P. Blaser, âExperimental Validation of CFD Hydrodynamic Models for Catalytic Fast Pyrolysisâ, Powder Technology, published online, December 2016.