Nitrogenous gas is produced when compounds containing nitrogen are decomposed, such as protein, urea and uric acid.

Microorganisms that live and multiply in an environment containing no free or dissolved oxygen.

Decomposition of organic substances caused by anaerobic bacteria, partially with release of biogas.

Fertiliser to be used for fermentation purposes.

Product of anaerobic biological decomposition or organic matter. Contains approx. 45-70 % methane, 30-55 % carbon dioxide, small quantities of nitrogen, hydrogen sulphide and other trace gases.

Plant for the production, storage and utilisation of biogas, including all necessary equipment and fixtures . Biogas is thereby produced by means of fermentation of organic substances.

The buffer capacity is the quantity of a strong acid required to adjust the pH to a predefined value (e.g. 4.4).

Colourless, non-flammable, non-toxic gas with a slightly acidic smell, produced together with water when an organic compound is combusted.

Simultaneous conversion of energy used into electrical (or mechanical) energy and into heat to be used for heating purposes (useful heat).

Biogas produced in the fermenter is saturated with water vapour and must be dried before it is used in the combined heat and power plant. This is done by installing a sufficiently dimensioned earth line in a condensate trap, or by drying the biogas.

Organic material that is not a fertiliser and is destined for fermentation.

Ratio between carbon and nitrogen in a substrate. The C/N ratio of the substrate to be fermented is important for a good fermentation process (ideal ratio: 13/30). The C/N ratio in the fermented substrate can be used to determine the availability of nitrogen for fertilisation (ideal: 13).

The decomposition of organic compounds consisting of many atoms into smaller molecules by means of biotic or non-biotic processes. Biotic decomposition is caused by biological processes (e.g. by enzymes or microorganisms). Non-biotic decomposition is caused by chemical reactions (e.g. slow oxidation, combustion, conversion) or physical influences (e.g. UV radiation).

Property of a substance that can be decomposed by biochemical, chemical or physical reactions. The end products of the reactions are either other compounds (metabolites) or in the case of complete mineralisation CO₂, H₂O, NH₃.

Biological or chemical process for the removal of sulphur from biogas.

Dry content of a substance mixture after drying at 105 °C.

Average retention time of the substrate in the fermenter.

Release of fumes, gases, dust, affluent or odours into the environment. Emissions also include noise, vibration, light and heat radiation.

Device for the separation of non-emulsified organic oils and fats, installed for example in wastewater systems of restaurants, commercial kitchens, meat factories, meat and fish processing plants, margarine factories and oil mills (see DIN 4040).

Material left over in the fermenter after biogas production, biogas production by-product.

Container or pit in which slurry, liquid manure as well as fermented substrate are stored before further use.

Vessel in which the substrate is decomposed by microorganisms and biogas is released in the process.

Time of the full loading of a plant when the total usage hours and the average degree of utilisation within one year are converted to a utilisation rate of 100%.

Structure placed on fermentation vessel in which biogas is collected for further use.

Room or area where the gas tank is installed.

Gastight vessel or foil bag in which biogas is temporarily stored.

Unit for the production of electricity and heat by means of an engine with an attached generator.

Combustible, strong toxic gas with an unpleasant pungent smell like rotten eggs which can, however, be tolerated in low concentrations.

Process step for reduction and/or elimination of disease agents and/or phytopathogens. BioAbfV or EC Hygiene regulations give information about the process.

Heat transfer coefficient, also known as K value, is a measure for thermal insulation properties. It corresponds to the heat that is conducted through a surface of one square meter of a material at a temperature difference of one degree Celsius. The smaller the K value, the lower the heat loss.

The marketing and selling of goods, dispatch of products and storage of goods for the purpose of selling.

Colourless, odourless and non-toxic gas. Releases carbon dioxide and water when combusted. Methane is one of the key greenhouse gases and is contained in biogas, natural gas, sewer gas and landfill gas.

The gases nitrogen monoxide (NO) and nitrogen dioxide (NO₂) are also referred to as NO_x (nitrogen oxides). They occur in all combustion processes (especially at high temperatures) when the nitrogen in the air reacts with the oxygen, or where compounds containing nitrogen are oxidised.

Organic content of the substance after removal of the water and any inorganic substances. Normally determined by drying the substance at 105 °C and combustion at 550 °C.

Preliminary treatment of a material (e.g. chopping, removal of unwanted substances, homogenisation, etc.).

Areas in which an explosive atmosphere might occur, due to local or operational conditions.

The rate of the biological or chemical degradation of organic compounds,

Collective term describing any biomass that is used as a material or for the generation of energy (not including foodstuff and animal feed). Normally, they consist of products from agricultural production or forestry, such as timber, flax, rapeseed, sugar and starch extracted from sugar beet, potatoes or maize that are used for a secondary purpose.

Method for the transfer of non-pumpable substrates or substrate mixtures to the fermenter.

Colourless gas, with a pungent smell, produced by combusting sulphur or roasting sulphides. The corresponding aqueous solution is known as sulphurous acid.

Organic bio-degradable material collected for the purpose of fermentation for the production of biogas.

Quantity of material feed to and processed in a plant per time unit.

VOA/TAC is the ratio of volatile organic acids to total anorganic carbon (carbonate buffer capacity).

Organic content of the material brought into the fermenter relative to the usable fermenter capacity per time unit. Expressed in kg ODS/m³*d.