loading page

Linking maximal shear rate and energy dissipation circulation function in airlift bioreactors
  • +4
  • Mateus Esperança,
  • Mariane Buffo,
  • Caroline Mendes,
  • Guilherme Rodriguez,
  • Rodrigo Bettega,
  • Alberto Badino,
  • Marcel Otavio Cerri
Mateus Esperança
Federal Institute of Education, Science and Technology of São Paulo

Corresponding Author:[email protected]

Author Profile
Mariane Buffo
University of São Carlos
Author Profile
Caroline Mendes
Federal University of Rio Grande
Author Profile
Guilherme Rodriguez
Federal University of Itajubá
Author Profile
Rodrigo Bettega
University of São Carlos
Author Profile
Alberto Badino
University of São Carlos
Author Profile
Marcel Otavio Cerri
Author Profile


Pneumatic reactors are an important class of bioreactors widely used in biotechnological processes. The growing interest in these reactors is mainly related to their good mass transfer capacity, as well as lower operating costs, due to the simple mechanical structure. Knowledge of the transport phenomena and hydrodynamics of bioreactors is important to enable definition of the best bioreactor model and operating conditions for a specific bioprocess. Several performance parameters are used to evaluate bioreactors, with the imposed shear being one of the most difficult to quantify. For stirred tanks, the fragmentation of microorganisms has been well correlated with a hydrodynamic parameter called the “energy dissipation/circulation function” (EDCF). However, there have been no estimates of the EDCF for pneumatic bioreactors. The present work proposes a methodology to estimate the EDCF for different pneumatic bioreactors and operating conditions. The difficulty in estimating the EDCF for pneumatic bioreactors is in defining the volume of higher energy dissipation. Here, this was achieved employing the maximal shear rate obtained using computational fluid dynamics simulations. The estimated volume was validated by comparing pellet fragmentation in conventional and pneumatic bioreactors, under conditions that led to similar EDCF values.