In future, alternative biomass fuels will be able to help replacing fossil fuels. Horse manure offers here an enormous potential. The pelletisation of horse manure with the patented Bioburn-process provides several advantages in regards to handling and combustion. Goal of this project is to ensure a quality for the horse manure pellets to ISO 17225 standard and a quality management as well as a compliance with the current emission limits of LRV. First, different mixtures of horse manure, cereal waste and mycotoxin-grain have been pelletized with an extruder. Then the pellets have been analysed with respect to their elemental composition and combustion behaviour. Compared to wood pellets, this horse manure pellets have following differences: ? Very good mechanical properties:
- homogeneous, accurate to dose, good distribution on the grate
- Similar values in water content, heating value and bulk density compared to wood chips
- Massive higher ash content and mineral metals as well as higher nitrogen- and chlorine content
- Lower ash melting temperature (comparable to straw)
The ash content and in particular the substances potassium and chlorine, that are responsible for aerosol formation, are seen as critical parameters in regards to dust emissions, slagging and the formation of PCDD. Moreover, the high content of nitrogen leads to higher NOX-emissions. On basis of the fuel analysis a suitable combustion system could be found with the 550 kW grate furnace from Schmid energy solutions, with can handle also fuels with high ash content. During the combustion tests in part load and full load comprehensive flue gas analysis have been done. The high level of contaminants in the fuel could also be found in concentrated form in the ash. All ash fractions have been analysed also for PCDD. The measured values confirm the correlation of PCDD content in the ash and the flue gas.