Biogas generation to achieve the best quality, in addition to preparing raw materials in order to achieve the levels of carbon to nitrogen ratio (C / N) = 20-30, also requires the management of gastrointestinal micro-environment in the tub (digester) in order to achieve optimum pH (6 to 7), mesophilic temperature (25 to 40 C degrees) and the homogeneous mixing for avoiding the deposition of solid material (total solid).

Stirring in the digester needs to be done to obtain a homogeneous mixture of substrates with small particle size. Stirring during the fermentation process also serves to prevent objects floating on the surface of the liquid as well as beneficial for methanogens mixed with the substrate.

Stirring also provide temperature and pH conditions that are uniform in biodigester and facilitate the release of gases produced by bacteria. Based on the interests of improving the quality of the resulting biogas, digester mixing offered as an optional for each Biogas Digester Biophosko that we present. Mechanical stirrer shaft has a length of 1.2 m, 1.75 m propeller shaft and propeller rotation median up to 1.2 m.

Digester mixer would be appropriate for all types of Biogas Digester (BD 3000L, BD 5000L and BD 7000L). Made of acid and corrosive-resistant metals, lightweight operated, has a propeller from strong metal and have a low rotation speed, tailored to the needs of the preservation process of fermentation by bacteria methanogens.

It is known that the growth of bacteria suitable medium, ie formed from organic materials within a specified time. Stirring is too soon would hinder the process of anaerobic fermentation actually inhibited.