Drybench Bioreactor.

OTR and OUR calculator

The oxygen transfer rate a vessel can give against the oxygen uptake rate a culture needs, from kLa, C* and the cells' demand.

The oxygen transfer rate a vessel gives, OTR = kLa·(C* − C), against the oxygen uptake rate a culture needs, OUR = qO₂·X. When OUR exceeds the most the vessel can transfer (C at zero), oxygen runs out.

kLa (per hour)

Temperature (°C)

Headspace pressure (atm, absolute)

Inlet O₂ (% of the dry gas)

Dissolved oxygen (% air saturation)

Specific oxygen uptake, qO₂ (mmol/g/h)

Biomass (g/L)

C* 6.73 mg/L (Benson and Krause, as the USGS documents them; the gas phase taken as the inlet's)

OTR at this DO: 58.9 mmol/L/h
Most the vessel can transfer (C = 0): 84.1 mmol/L/h
OUR: 50.0 mmol/L/h

The vessel can supply this culture's demand.

31.998 mg O₂ per mmol.

Open in the app

Limits

Teaching and estimation model, not a validated process model.
The rescue cascade stays within the agitation, gas-flow and oxygen-enrichment limits you enter, and ignores cooling capacity, vessel pressure and gas-safety limits. Oxygen enrichment near flammable solvents or vapours is a fire and explosion hazard. Do not run a vessel from these outputs without your own engineering review.

A simulation, not a forecast. Every output follows from the model equations and the parameters you entered. It is a teaching and estimation model, not a validated process model, and not a prediction for any real strain, vessel or process.

Equations