Evaluation of temperature changes in anaerobic digestion process

The study examines the effect of temperature fluctuations on biogas production efficiency in biogas plants with the aim of evaluating the temperature flexibility of the process. Laboratory scale batch reactors were prepared with the chosen substrate (Dried Distillers Grains with Soluble, DDDS) and the study was conducted in three batches. A biogas formation potential test was implemented in each batch in a temperature-controlled room and in a temperature controlled water bath. The temperature changes took place on the third day of tests to evaluate the effect of 5°C, 10°C and 15°C increases on biogas production efficiency in separate test sets. Batch experiments showed that it is possible to ensure process recovery after 5°C and 10°C increases. Overall, the specific biomethane production was obtained between 364-412 Nml CH4 / g oDM. Unlike 5°C and 10°C increases, after 15°C increase a lower methane content was obtained. These results show that it is possible to have flexible temperature operation in the process, even with high-temperature increases