Investigation on internal structure of pellets with halloysite additive and effect of moisture content before the pelletizing process

The article presents analysis of the particle size distribution inside pellets and the influence of moisture content before pelletization process on final product mechanical strength. The following types of biomass were used without and with the content of additive (halloysite): Polish wheat straw-(SP-K), miscanthus (DM), cereal straw (DS) and herbaceous pellets (BZ). Particles inside pellets were characterized by a grain size smaller than 3 mm and the cumulative weight percent passing through the sieve with mesh screen 1 mm for each sample was higher than 70 %. The moisture content before pelletization process for tested materials was in the range of 25%-30% depending on the material which was used, while values of mechanical strength of pellets were within the range of 77.7%-96.2% (depending on the type of material and moisture content before the pelletization process).