What is the oxygen transfer rate?
The oxygen transfer rate (OTR) must be known, and if possible predicted to achieve an optimum design operation and scale-up of bioreactors. Oxygen transfer is often the rate-limiting step in the aerobic bioprocess due to the low solubility of oxygen in the medium.
What is kLa oxygen?
kLa is a gas transfer coefficient, a measurement of the capacity of the bioreactor to transfer oxygen into the cultures. kLa is influenced by factors such as bioreactor geometry, gas flow, superficial gas velocity, impeller type and speed, and power input for mixing per unit reaction volume.
What is the actual mass of oxygen transfer per unit time?
5. _________ is the actual mass of oxygen transferred per unit time. Explanation: The OTR is the actual mass of oxygen transferred per unit time and it is the key process variable for design. The DO saturation concentration is the concentration of dissolved oxygen at saturation with no reactions in the liquid.
What is volumetric mass transfer coefficient?
Volumetric mass transfer coefficient (relative to the unit liquid volume) is one of the most important transport characteristics used in the scale-up, design and performance optimization of mechanically agitated gas-liquid contactors.
For which type of mass transfer does oxygen balance method is used?
Explanation: The oxygen balance technique is used for gas-liquid transfer mass transfer and is used for the measurement of the KLa values.
Why do we calculate mass transfer coefficient?
This can be used to quantify the mass transfer between phases, immiscible and partially miscible fluid mixtures (or between a fluid and a porous solid).
What is mass transfer coefficient kLa?
The kLa (Volumetric Mass Transfer Coefficient) and the OTR (Oxygen Transfer Rate) detail how efficient oxygen is transferred from the gas bubbles into the bioreactor medium, i.e. how much oxygen is available for the cultivated biomass.
What is mass transfer coefficient KLA?
How do you calculate Standard oxygen Transfer Efficiency?
The standard oxygen transfer rate (SOTR, g/m3 · s) is shown to be related to EI through a second-degree equation: SOTR = −11.5 EI2 + 2.27 EI (r2 = 0.951). The model applies over a wide range of diffuser types, diffuser densities, tank dimensions, and specific air flows.
How to calculate the mass transfer coefficient of oxygen?
(1) d [V L · c L] d t =k L a (c * −c L) V L where kLa is the volumetric mass transfer coefficient (min −1 ), ( c* − cL) is the driving force causing the mass transfer, c* and cL refer to the liquid phase oxygen concentration at saturation and at any time, respectively.
How is the rate of oxygen uptake determined?
Since Co * is constant at a fixed air pressure, Co is determined by three factors: the specific oxygen uptake rate Qo, which is determined by the biological system, cell concentration X, and the volumetric mass transfer coefficient, kLa.
How is co constant at fixed air pressure?
Since Co* is constant at a fixed air pressure, Co is determined by three factors: the specific oxygen uptake rate Qo, which is determined by the biological system, cell concentration X, and the volumetric mass transfer coefficient, k L a.
When does the power of oxygen transfer increase?
From: Computational Modeling in Biomedical Engineering and Medical Physics, 2021 Oxygen transfer would be expected to increase if mixing time is used as the scale up criterion. This can easily be seen with the relative increase in power of D5 with constant mixing compared with only D 3 with constant oxygen transfer.