Biogas is produced during the anaerobic digestion of organic material. Substrates are specifically grown energy plants like maize, previously unused parts of plants, liquid manure, wastewater sludge and other bio-waste. The organic material is biodegraded by microorganisms into biogas, which is a mixture of mainly methane and carbon dioxide. In many cases the organic material also contains foam active substances like proteins. During  digestion disturbing foam might occur if the process in not correctly driven and foam active substances are present: inside the digester, during the isolation of the biogas from the digestion substrate, during the digestate evaporation etc.

The selected Struktol antifoaming agents are well balanced between destruction of already built foam, prevention of foam and degassing of high viscous digester content.

A good distribution of the antifoam in the digester is important. The best addition point would be into the substrate just before it is pumped into the digester. For the digestate evaporation the best addition point would be after the decanter and after the adjustment of the pH-value.

Addition rates depend on the amount of foam activity and must be found out by pretests.