Process Temperature

A constant process temperature is critical to successfully operate an anaerobic digester. An increase in temperature leads to increased bacterial activity with higher growth rates, faster metabolism and elevated nutrient demand. 

 

An increase in temperature leads to increased bacterial activity with higher growth rates, faster metabolism and elevated nutrient demand.

If temperature falls below a certain optimum bacterial metabolism and subsequent biogas production decelerates. Methane production decreases or is completely stopped. At the same time CO2 levels rise. 

Acid forming bacteria respond to an increase in temperature with excelerated growth and will outgrow the methanogenic bacteria. Rapid changes in temperature will result in similar effects as sudden increases in organic loading. Therefore a constant temperature is critical to the anaerbic digester 

 

Mesophilic - Thermophilic

Anaerobic digesters are operated at two different temperatur ranges - mesophilic or thermophilic. Process wise digesters operated under mesophilic conditions succeeded in the market when it comes to digesting on-farm materials. 

 

The optimum temperatur for mesophilic bacteria ranges between 86°F - 96°F, whereas thermophilic bacteria metabolize best at temperatures ranging from 122°F to 140°F. 

    • digester technology
    • biogas basics
    • microbiology behind anaerobic digestion
    • Buswell and Boyle
    • biogas composition
    • organic load
    • pH and volatile fatty acids (VFA)
    • suitable substrates
    • biogas yield
    • biogas calculator