In biological fermentation processes, PID (Proportional- Integral-Derivative) controllers are commonly used to regulate various parameters such as temperature, pH, dissolved oxygen concentration, and nutrient feed rates. These controllers play a crucial role in ensuring optimal conditions for the growth and metabolism of microorganisms involved in the fermentation process, ultimately leading to higher yields and product quality. TYPES : Controllers can be classified into Three main types: ➤ Proportional controllers. ➤ Integral controllers. ➤ Derivative controllers.

1. TYPES OF CONTROLLERS - PID
IN
FERMENTATION PROCESS
PRESENTED BY:
J.Sanjay stanlin ( 121012101426 )
M.Mohammed Dhanish ( 121012101421)
3rd year B.Tech Biotechnology
XBT 602 - PROCESS
BIOTECHNOLOGY
( UPSTREAM )
SUBMITTED TO:
Ms. P Mala
Assistance Professor
Department of BioTechnology
Periyar Maniammai Institute Of
Science and Technology
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2. • INTRODUCTION
• TYPES
• APPLICATION
• ADVANTAGES & LIMITATIONS
CONTENT:
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3. • In biological fermentation processes, PID (Proportional-
Integral-Derivative) controllers are commonly used to
regulate various parameters such as temperature, pH,
dissolved oxygen concentration, and nutrient feed rates.
• These controllers play a crucial role in ensuring optimal
conditions for the growth and metabolism of microorganisms
involved in the fermentation process, ultimately leading to
higher yields and product quality.
INTRODUCTION:
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4. TYPES :
Controllers can be classified into Three main types:
➤ Proportional controllers.
➤ Integral controllers.
➤ Derivative controllers.
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5. PROPORTIONAL CONTROLLERS:
• The proportional term adjusts the control output based
on the magnitude of the error.
• For example, if the actual temperature is far from the
setpoint, the proportional term will drive the control
output proportionally to reduce the error.
• The proportional component of the PID controller
responds to the current error between the desired
setpoint and the actual value of the controlled parameter.
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6. INTEGRAL CONTROLLERS:
• In fermentation processes, disturbances or changes in the
environment may cause a steady-state error between the
setpoint and the actual value.
• The integral term continuously integrates the error over
time and adjusts the control output to eliminate this
steady-state error.
• The integral component of the PID controller accounts
for the accumulated error over time.
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7. DERIVATIVE CONTROLLERS:
• In biological fermentation, rapid changes in the controlled
parameters (e.g., sudden temperature spikes) can be detrimental to
the process.
• The derivative term helps dampen these sudden changes by
predicting the future behavior of the error and adjusting the control
output accordingly.
• For example, if the temperature in a fermenter is rising too quickly,
the derivative term can detect this trend and reduce the control
output to prevent overshooting the setpoint.
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9. APPLICATION:
• Controllers regulate fermentation temperature, pH, dissolved oxygen levels,
and nutrient concentrations to optimize microbial growth and product
formation.
• Temperature controllers maintain consistent fermentation temperatures,
crucial for enzyme activity and microbial metabolism.
• pH controllers adjust acidity or alkalinity to create optimal conditions for
microbial growth and product yield.
• Dissolved oxygen controllers ensure sufficient oxygen levels for aerobic
microorganisms without causing oxygen toxicity.
• Nutrient feed controllers manage the addition of carbon sources, nitrogen
sources, and other nutrients to support microbial growth.
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10. ADVANTAGES:
• Controllers ensure optimal fermentation conditions, leading to
improved microbial growth and product formation.
• Consistent product quality is achieved through stable process
conditions maintained by controllers.
• Precise control enhances product yield by maximizing microbial
metabolism efficiency.
• Operating costs are reduced as controllers optimize resource
usage and minimize waste.
• Controllers contribute to process safety by preventing
deviations and hazards.
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11. LIMITATIONS:
• Implementation and maintenance of control systems can
be complex and costly.
• Sensor accuracy and reliability can affect control system
performance.
• Variability in microbial behavior and environmental factors
may introduce uncertainty.
• Response time limitations can impact control performance
in dynamic environments.
• Improper tuning may lead to overcontrol, oscillations, or
instability.
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MCQ -
Questions:
1 . Which of the following parameters is NOT
commonly regulated by PID controllers in biological
fermentation processes?
A) Temperature
B) pH
C) Dissolved oxygen concentration
D) Fermentation duration
2 . What does the integral component of a PID
controller in fermentation processes primarily
address?
A) Current error between setpoint and actual value
B) Rapid changes in controlled parameters
C) Accumulated error over time
D) Future trends in error rate
A) Proportional (P) Control
B) Integral (I) Control
C) Derivative (D) Control
D) None of the above
4 . Which controller ensures sufficient oxygen levels
for aerobic microorganisms without causing oxygen
toxicity?
A) Temperature controller
B) pH controller
C) Dissolved oxygen controller
D) Nutrient feed controller
5 . What aspect can make controlling fermentation
processes more challenging?
A) High implementation and maintenance costs
B) Unpredictable changes in microbial behavior
C) Slow response time of control systems
D) Limited flexibility in adjusting production
requirements
3 . Which component of a PID controller in
fermentation processes adjusts the control
output based on the magnitude of the error?

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MCQ
Answers:
1 . D) Fermentation duration
2 . C) Accumulated error over time
3 . A) Proportional (P) Control
4 . C) Dissolved oxygen controller
5 . B) Unpredictable changes in microbial behavior

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References
:
• https://www.sciencedirect.com/science/article/abs/pii/
S0959152418303202
• https://www.slideshare.net/DhanyaKc/control-systems-
in-fermenter
• https://www.slideshare.net/nandhujaan/bioreactor-
control-system

15. THANK YOU!!!
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