Mechanical Decomposition of Substrates for Increase of the Biogas Yield

Besides encymes the mechanical decomposition of substrates is most widespread. We as biogas plant operators use mechanical decomposition of substrates as long as we operate plants. In case of liquid manure animals made the decomposition, the shredder at the harvest in case of silage. A decomposition beyond this requires considerable expense on energy and wear […]

About the Sense of Decomposition Procedures

  Many „new“ procedures to increase the biogas yield from the substrates are developed and propagated particularly in economically difficult times. The best known techniques at the market are use of enzymes for decomposition and for decrease of viscosity mechanical decomposition by a crusher or an extruder ultrasonic decomposition thermal decomposition by heating up. I […]

Sense and Necessity of the Micronutrient Addition

Micronutrients or trace elements (these are mostly heavy metals) are needed in all biogas plants. The micronutrients are the central atoms in the enzymes which must be produced by the methane bacteria in order to produce biogas. Without micronutrients there is also no biogas. A part of the needed micronutrients is mostly delivered with the […]

Acidification of the Digester

At the operation of biogas plants acidification of the digester is one of the most expensive problems. When the digester biology is acidotic, it can possibly last months, till the plant has its full performance again and the planned revenues flow again. Hence it is especially important to control the digester biology continually and to […]

Analysis of the Supply with Micronutrients in Biogas Plants – Expensive and Useless?

The analysis of the micronutrient concentrations in the digester supplies no usable information about the level of supply of the digester biology. These costs can be saved. The use of individual mixtures makes no sense, as the level of supply cannot be sensefully detected. A safe micronutrient supply of the digester biology is only possible by the correct addition of a defined product adjusted to the growth of the bacteria population.

Selfheating and Cooling of Digesters

When I started constructing and commissioning the first high-loaded biogas digesters (digester load 8-10 kg oDM/cbm/d) in 2005, an unexpected phenomenon appeared – the digesters warmed up by themselves in summer without activated heating. The real problem was the too fast increase of temperature, leading to a breakdown of the biology. In a few weeks the planned digester temperature of 39 °C increased to 43 °C, and the digester biology suddenly became unstable.

The Influence of Temperature on the Biogas Production

The still common understanding assumes the existence of a mesophilic (35 – 40 °C) as well as a thermophilic (50 – 55 °C) temperature range for the biogas production. More stable biological process conditions should be enabled by the mesophilic range, the thermophilic range is said to be faster and to produce more gas. 20 […]