The question of the extent to which such residual materials can be used as an energy source is therefore of great importance. This question was investigated as part of a research project carried out by the Institute for Regenerative Energy Technology (in.RET) in cooperation with the company M.A.M. Energietechnik GmbH from Suhl.

In view of the growing need for horse farms to dispose of their manure, the project focussed on the use of horse manure. The material first had to be dried using an innovative low-temperature drying process developed by the project partner. The dried source material was first pelletised at in.RET in order to produce homogeneous and possibly standardisable fuels. The pellets were then burnt in a 30 kW biomass boiler and the resulting dust and pollutant emissions were measured. The chemical and physical properties of the pellets were compared with the specifications of the relevant EU standard, the resulting emissions were compared with the limit values of the 1st BImSchV and the ash was analysed. These tests and the results obtained will be discussed in more detail in the presentation.

As a result, it was shown that pelletising the raw materials produces a fuel that largely meets the requirements of the EU standard and that agricultural residues can be used in small plants. The CO and NOx emissions determined during the combustion tests showed that complete combustion of such residue pellets is feasible. Somewhat more problematic are the dust emissions and ash content, which increase significantly compared to the combustion of pure wood pellets. There are approaches for optimising these fuels, which are to be investigated in further research work.