CPFD Modeling to study the Hydrodynamics of an Industrial Fluidized Bed Reactor for Alumina Chlorination


  • Zahir Barahmand
  • Chameera Jayarathna
  • Chandana Ratnayake




CPFD simulation, bubbling regime, fluidized bed reactor, reactor design, alumina chlorination


Aluminum is one of the most used metals. Since aluminum has a unique combination of appealing properties and effects, it allows significant energy savings in many applications, such as vehicles and buildings. Although this energy-saving leads to lower CO2 emissions, the production process of aluminum still dramatically impacts the environment. The process used exclusively in the aluminum industry is the Hall-Héroult process with a considerable carbon footprint and high energy consumption. As the best alternative, Alcoa's approach (which is not industrialized yet) is based on the chlorination of processed aluminum oxide, reducing the traditional method's negative impacts. Further to Alcoa’s effort, this study aims to investigate the possibility of a new low-carbon aluminum production process. This aim can be achieved by designing an industrial fluidized bed reactor with an external (due to high corrosion inside the reactor) gas-solid separation unit. The aim is to handle 0.6 kg/s of solid reactants and produce aluminum chloride as the main product. The research focuses on determining the best bed height based on the available reaction rates, choosing the best reactor dimension to reduce particle outflow under isothermal conditions (700°C). Autodesk Inventor® and Barracuda® are used for 3D modeling of the reactor and CFD simulation for multiphase (solid-gas) reactions, respectively. Although results have shown that the bed aspect ratio (H/D; H- bed Height and D- bed Diameter) does not affect the reaction, it highly affects the reactor’s hydrodynamics and particle outflow. The final design shows the best hydrodynamics belongs to bed aspect ratio equal to 2.


Adoption of the Paris Agreement (FCCC/CP/2015/L.9/Rev.1). United Nations, 2015. https://unfccc.int/resource/docs/2015/cop21/eng/l09r01.pdf

Aluminium Market Size, Trends | Global Industry Forecast [2027], 2021.

Z. Barahmand. Design of an Industrial Chlorination Reactor Using CPFD Simulations [Master Thesis]. University of South-Eastern Norway, 2021.

Z. Barahmand, O. Aghaabbasi, E. K. L. Rustad, J. L. Salcido, C. Jayarathna, and C. Ratnayake. Designing of a medium-scale circulating fluidized bed reactor for chlorination of processed aluminum oxide. In Proceedings - 1st SIMS EUROSIM Conference on Modelling and Simulation, Finland, 2021.

Z. Barahmand, C. Jayarathna, and C. Ratnayake. CPFD simulations on a chlorination fluidized bed reactor for aluminum production: An optimization study. In Proceedings - 1st SIMS EUROSIM Conference on Modelling and Simulation, Finland, 2021a.

Z. Barahmand, C. Jayarathna, and C. Ratnayake. Study of the thermal performance of an industrial alumina chlorination reactor using CPFD simulation. In Proceedings - 1st SIMS EUROSIM Conference on Modelling and Simulation, Finland, 2021b.

Z. Barahmand, C. Jayarathna, and C. Ratnayake. The effect of alumina impurities on chlorination in a fluidized bed reactor: A CPFD study. In Proceedings - 1st SIMS EUROSIM Conference on Modelling and Simulation, Finland, 2021c.

E. L. Bray. Aluminum Statistics and Information. United State National Minerals Information Center, 2021. https://www.usgs.gov/centers/nmic/aluminum-statistics-and-information

C. Clemence. Leaders Emerge In The Aluminium Industry’s Race To Zero Carbon. Aluminium Insider, 2019. https://aluminiuminsider.com/leaders-emerge-in-the-aluminium-industrys-race-to-zero-carbon/

D. Geldart. Types of gas fluidization. Powder Technology, 7(5), 285–292, 1973. doi:10.1016/0032-5910(73)80037-3.

E. Hartge, D. Rensner, and J. Werther. Solid concentration and velocity patterns in circulating fluidized bed. In P. Basu & J. F. Large (Eds.), Circulating Fluidized Bed Technology, pages 165–180. Pergamon, 1988. doi:10.1016/B978-0-08-036225-0.50020-4

M. Horio. Circulating Fluidized Beds (J. R. Grace, A. A. Avidan, & T. M. Knowlton, Eds.). Springer Netherlands, 1977. doi:10.1007/978-94-009-0095-0_2

A. Kovács, C. Breward, K. Einarsrud, S. Halvorsen, E. Nordgård-Hansen, E. Manger, A Münch, and J. Oliver. A heat and mass transfer problem for the dissolution of an alumina particle in a cryolite bath. International Journal of Heat and Mass Transfer, 162, 120232, 2020. doi:10.1016/j.ijheatmasstransfer.2020.120232

M. Kruse and J. Werther. 2D gas and solids flow prediction in circulating fluidized beds based on suction probe and pressure profile measurements. Chemical Engineering and Processing: Process Intensification, 34(3), 185–203, 1995. doi:10.1016/0255-2701(94)04004-4

D. Kunii, O. Levenspiel. Fluidization Engineering. Butterworth-Heinemann, 1991.

R. Mabrouk, J. Chaouki, and C. Guy. Exit effect on hydrodynamics of the internal circulating fluidized bed riser. Powder Technology - POWDER TECHNOL, 182, 406–414, 2008. doi:10.1016/j.powtec.2007.07.008

Mapping resource prices: The past and the future. ENV.G.1/FRA/20410/0044; pages 370. ECORYS, 2012.

National Fuels and Energy Conservation Act, S. 2176. U.S. Government Printing Office, 1973.

A. W. Nienow. Fluidization of dissimilar materials. Fluidization, 357–381, 1985.

B. Øye, B. Could the chloride process replace the Hall-Héroult process in aluminium production? SINTEFblog, 2019, March 28. https://blog.sintef.com/sintefenergy/energy-efficiency/could-the-chloride-process-replace-the-hall-heroult-process-in-aluminium-production/

W. S. Peterson and R. E. Miller. Hall-Heroult Centennial: First Century of Aluminum Process Technology, 2007.

C. Philippsen, A. Vilela, and L. Zen. Fluidized bed modeling applied to the analysis of processes: Review and state of the art. Journal of Materials Research and Technology, 4(2),208–216, 2015. doi:10.1016/j.jmrt.2014.10.018

S. Prasad. Studies on the Hall-Heroult aluminum electrowinning process. Journal of the Brazilian Chemical Society, 11, 245–251, 2000. doi:10.1590/S0103-50532000000300008

M. Rhodes, H. Mineo, and T. Hirama. Particle motion at the wall of a circulating fluidized bed. Powder Technology, 70(3), 207–214, 1992. doi:10.1016/0032-5910(92)80055-2

R. Senior and C. Brereton. Modelling of circulating fluidised-bed solids flow and distribution. Chemical Engineering Science, 47(2), 281–296, 1992. doi:10.1016/0009-2509(92)80020-D

J. Sinclair, and R. Jackson. Gas‐particle flow in a vertical pipe with particle‐particle interactions, 1989. doi:10.1002/AIC.690350908

Survey of potential processes for the manufacture of aluminium (ANL/OEPM-79-4). Little (Arthur D.), Inc., Cambridge, MA (USA), 1979.

A. Svensson, F. Johnsson, and B. Leckner. Fluid-dynamics of the bottom bed of circulating fluidized bed boilers. In Proceedings - 12th International Conference on Fluidized-Bed Combustion, 2, 887–897, 1993.

The Aluminium Effect—European Aluminium. 2021. https://european-aluminium.eu/about-aluminium/the-aluminium-effect/

J. Thonstad. Aluminium Electrolysis: Fundamentals of the Hall-Héroult Process. Aluminium-Verlag, 2001.

M. Van de Velden, J. Baeyens, J. Degrève, and J. Seville. The residence time distribution of the gas phase in circulating fluidized beds (CFB). In Proceedings - European Congress of Chemical Engineering, 16–20, 2007.

W. Yang. Handbook of Fluidization and Fluid-Particle Systems. CRC Press, 2003.

Y. Yang, Y. Jin, Z. Yu, and Z. Wang. Investigation on slip velocity distributions in the riser of dilute circulating fluidized bed. Powder Technology, 73(1), 67–73, 1992. doi:10.1016/0032-5910(92)87008-X

H. Zhang, L. Shu, and S. Liao. Generalized Trapezoidal Fuzzy Soft Set and Its Application in Medical Diagnosis. Journal of Applied Mathematics, e312069, 2014. doi:10.1155/2014/312069

W. Zhang, Y. Tung, F. Johnsson. Radial voidage profiles in fast fluidized beds of different diameters. Chemical Engineering Science, 46(12), 3045–3052, 1991.