The objective of this research is the improvement
and optimization potentials of the combustion behavior of wood–straw pellets in terms of sintering and
release of inorganic material. The ash melting behavior and the associated emissions can be influenced by
the wood/straw ratio and by mineral additives. Thus, experiments are carried out testing different wood/
straw ratios as well as the influence of calcium hydroxide and kaolin as mineral additives. Results show
that increased wood addition has a very poor effect on sinter behavior. Calcium hydroxide and kaolin,
however, help to elevate the ash melting temperature. Results of atomic absorption spectroscopy and
X-ray diffraction indicate that calcium hydroxide increases the release of potassium, whereas kaolin
binds potassium in the ash. Due to kaolin addition, new silicates are formed in the ash, which include
not only potassium but also sodium, magnesium and calcium.