To ensure that hydrolysis cellulose to glucose is at rate of conversion at 51% as mentioned in the mass balance calculation, there are three control system need to be install. The first three control systems are referring to the jacketed mixing vessel and the last control system is for the tubular membrane reactor

 

• pH Control for the solution inside the mixing vessel

pH value of the mixing solution in vessel need be control to provide best condition for the cellulase enzyme to perform hydrolysis of the cellulose. pH value can be control by manipulating the flow of the buffer solution into the mixing vessel and using feedback control strategy.

• Temperature Control for the solution inside the mixing vessel

Temperature of the solution also another parameter needs to be control in order to give suitable condition for the enzyme to work at its best. Temperature of the solution can be control by manipulating the flow of steam in into the jacket of the mixing vessel and using feedback control strategy.

 

• Level Control for the solution inside the mixing vessel

Level of solution inside the mixing vessel need to be control to ensure there is no overflow and overload happen for the mixing vessel. Level of the solution can be control by manipulating the flow of mixed substrate leaving the mixing vessels and using feedback control strategy.

• Pressure Control for the tubular membrane reactor

Pressure in the tubular membrane reactor need to be control to ensure the flow of permeate leaving the reactor is same with the flow of mixed substrate entering the reactor. The pressure can be control by manipulating the flow of air into the reactor and using feedback control strategies.

 

Controlled Variables:

• Temperature of the solution inside the mixing vessel

• pH value of the solution inside the mixing vessel

• Pressure in the tubular membrane reactor

• Flow rate of the permeate leaving the reactor

 

Manipulated Variables:

• Flow rate of steam into jacket

• Flow rate of buffer solution into mixing vessel

• Flow rate of air into tubular membrane reactor

 

 

Disturbance Variables:

• Flow rate of the pretreated substrate

• Flow rate of cellulose

• Flow rate of the recycle slurry

• Flow rate of makeup buffer/cellulase

Type of control algorithm

Type of control algorithm: using PID controller.

Reason:

• Need proportional control action, for quick response once the error is detected

• Integral control action is needed to bring the controlled variables back into their own set points when there is changes happen to controlled variables (eliminates offset).

• Meanwhile, derivative control action is required to reduce the oscillatory response from the integral control action. Also it can helps to anticipate the behavior of the error, therefore people can take proper actions to avoid any changes from happen in the future.

Transfer Function of the reactor.

Since the hydrolysis is primarily happen in the jacketed mixing vessel, thus the concentration of the glucose produced in the whole process is highly depends on the process inside the mixing vessel. Below is the dynamic model for the process inside the vessel: