Temperature-based control of an anaerobic reactor using a multi-model observer-based estimator.

Area of Science:

• Environmental Science
• Biotechnology
• Chemical Engineering

Background:

• Anaerobic digestion is crucial for organic waste treatment.
• Reactor stability is challenged by organic overloads.
• Temperature influences microbial activity in anaerobic digestion.

Purpose of the Study:

• To develop and validate a temperature-based control strategy for stabilizing anaerobic reactors during organic overloads.
• To assess the impact of mesophilic-thermophilic temperature transitions on methane production rates.
• To improve effluent COD concentration control in UASB reactors.

Main Methods:

• Batch activity tests and reactor runs were conducted.
• Mesophilic-thermophilic temperature transitions were analyzed.
• A multi-model observer-based estimator was employed for control.
• A 10 L UASB reactor was used for testing the strategy.

Main Results:

• Methane production rate increased initially with temperature augmentation, especially under thermophilic conditions.
• Sustained thermophilic conditions (24h) showed inferior methane production compared to optimal mesophilic conditions (35°C).
• The proposed temperature-based control strategy stabilized effluent COD concentration during organic overloads.
• The strategy led to increased methanization rates and overall improved reactor stability.

Conclusions:

• Short-term temperature augmentation is a viable strategy for managing organic overloads in anaerobic reactors.
• Optimizing temperature control enhances both methane production and reactor stability.
• The multi-model observer-based estimator effectively stabilizes UASB reactors under dynamic loading conditions.