Ethanol Production by fermentation

At Fermenter

Sugar (crops) à ethanol (alcohol)

Pressure condition: 10 bar pressure

What is the transfer function for the reactor?

CSTR model tend to be simpler than models for other type of continuous reactor such as tubular reactors and packed bed reactors.

Mass Balance:

Assumptions:

The CSTR is perfectly mixed
The mass densities of the feed and product stream are equal and constant. They are denoted by ρ
The liquid volume V in the reactor is kept constant by an overflow line.

For these assumptions, the unsteady state mass balance for CSTR is:

(mass of flow rate in)-(mass of flow rate out)+(rate of generation)=(rate of mass accumulate)

Because V and  are constant it then reduce to

Energy balance for CSTR

Five additional assumptions:

The enthalpy change associated with the mixing of the feed and the liquid in the tank is negligible compared with the enthalpy change for the chemical reaction. In the other words, the heat of the mixing is negligible compared to the heat of reaction.
Shaft work and heat losses to the ambient can be neglected.
Assume it is first order of reaction.