The document discusses optimization of low temperature biogas production from biomass through anaerobic digestion. It describes an experiment using sludge from a dairy wastewater treatment plant in a two-stage continuous-flow reactor at 33±2°C. Various parameters were measured including biogas production, composition, temperature and organic compound levels. Calculations were done to model microbial growth and optimize bioreactor geometry based on factors like flow rate and biogas production. The results showed significant arguments for applying optimization techniques when designing anaerobic bioreactors.

1. Optimization of low temperature biogas production from biomass by anaerobic digestion Marek Markowski, Ireneusz Białobrzewski, Marcin Zieliński, Marcin Dębowski, Mirosław Krzemieniewski University of Warmia and Mazury in Olsztyn

3. The aim of the study The aim of the study was to determine the influence of some geometric parameters of the bioreactor on the performance of the continuous-flow-type low temperature biogas production from biomass by anaerobic digestion and to determine the optimal geometric parameters of the digester.

5. The experiment ← Fig.1: The two-stage mixed flow reactor scheme. ↓ Fig.2: Simplified flow scheme of the methanogenic part of the bioreactor for computational calculations

7. Calculations

8. Calculations The heat production :

9. Calculations The Monod’s model: The Contois’s model:

10. Microbial growth rate depending on temperature: Calculations

11. Calculations Initial conditions:

12. Optimization

13. Optimization The total biogas production was related with the flow rate, which depends on geometry of bioreactor, so:

14. Results Fig.3: Biomass concentration in the flow symmetry axis

15. Results Fig. 4 : Substrate concentration in the flow symmetry axis

16. Results Fig. 5 : Product concentration in the symmetry axis

17. Results Fig. 6 : Temperature in the symmetry axis

18. Results Fig. 6 : Temperature in the symmetry axis

20. Thank you for your attention! mgr inż. Konrad Nowak