As Biogas generally called, are all gases which result from microbial degradation of organic matters under anoxic conditions (under exclusion of oxygen). In addition to the classical biogas, there is also digester gas from sewage treatment plants as well as landfill gas, which results from fermentation of solid biomass/bio-waste, food leftovers, organic fertilizers, plant remains and energy crops.

Biogas can be used for energy in different ways, i.e. for heat production and/or for electrical power generation. All fermentation gases improve the ecological balance and today they have already a significant portion on the production of electricity.

To keep all processes during fermentation continuously at a high degree, it is necessary to have the knowledge about the process and the produced biogas. Therefore a precise and reliable measurement of biogas quantity (flow) and quality (analysis) is particularly important even for Monitoring projects. Thus process problems can already be recognized and intervened in the process at the early stages.

There are special challenges on the sensor systems and its expected operation time, since fermentation gas is a damp and corrosive gas by its components. Furthermore, the concentrations of these components are not constant. They change depending on the kind of substrates and/or process and/or process conditions. Despite varying gas composition, only with a combination of the gas flow measurement and analysis, an exact and reliable regulation to the mass of gas is possible.

Spaans babcock