Efficient biogas production from cattle manure in a plug flow reactor: A large scale long term study

Area of Science:

• Biotechnology
• Environmental Science
• Chemical Engineering

Background:

• Anaerobic digestion is a key technology for waste management and renewable energy production.
• Optimizing large-scale operations is crucial for industrial biogas applications.

Purpose of the Study:

• To evaluate the long-term performance of a large-scale plug flow reactor for cattle manure digestion.
• To assess biogas and methane yields, production rates, and microbial community dynamics.

Main Methods:

• Operation of a 3.85 × 10^4 m^3 plug flow reactor for three years.
• Maintaining hydraulic retention time of 25 days and substrate concentration of 7-10% total solids.
• Monitoring biogas production, methane content, and microbial populations.

Main Results:

• Average monthly biogas production reached 7.45 × 10^4 m^3.
• Stable stage methane production rate was 0.58 m^3/m^3·d with 56.4% methane content.
• Specific biogas and methane yields were 0.39 m^3/kg VS and 0.22 m^3/kg VS, respectively, with 59% substrate removal efficiency.

Conclusions:

• Long-term operation confirmed the technological viability of large-scale cattle manure treatment for biogas.
• The study highlights the industrial applicability of this method for sustainable energy production.
• Key bacterial and archaeal genera involved in the digestion process were identified.