scope:

Special consideration is given to agricultural biogas facilities since the on-farm digestion of animal excrement (semi-liquid manure, liquid manure, solid manure) makes a significant contribution to emission control, whereas the use of crops cultivated specifically for biodigesters can generate additional emissions. Considerations should go beyond the normal operation of a biogas facility, since the production of feedstocks, the operation of the facility and the recovery of waste materials, when efficiently managed, can create a material cycle which effectively controls emissions.

The present guideline describes agricultural biogas facilities irrespective of the capacity of the digester or the scale of use, e.g. provision of power to a connected combined heat and power plant (CHP).

For the purposes of this guideline, an agricultural biogas facility uses substrates of agricultural, horticultural or forestry origin. These include:

a) all types of farmyard manure (slurry, liquid manure, solid manure)

b) all harvest products from arable land, fresh or preserved, in parts or as whole plants

c) waste agricultural products (e.g. alcohol (spirits monopoly), juice, milk) from farms and co-operatives

d) by-products from this production (e.g. distiller's residues, pomace, rape cake)

e) substrates which, according to the German Renewable Energies Act (EEG), qualify for the renewable raw materials bonus and are not listed under a) to d)

This guideline does not apply to municipal biodigesters which use biowaste from separate collection systems (VDI 3475 Part 1 and Part 2).