Production and characterisation of pellets from rice straw and rice husk

Residues from rice harvest (i.e. straw and husk) were pelletised and the main properties of the products were evaluated. Pellets were produced in a commercial pelletiser with a maximum capacity of 200 kg/h from the local company Nova Pellet (Novara, Italy). The feedstock was collected from a nearby farm and left to air dry. No ligand was necessary as moisture of biomass was in the range 10–14%. The samples were characterized in terms of their physical, chemical and physico-chemical properties. In addition, their mechanical performance was assessed by means of axial and diametral compression tests and durability tests. All the analysed properties were compared with the established quality standards for non woody pellets. In general, rice straw pellets presented better properties with all their parameters falling into the quality standards. On the contrary, rice husk pellets fell out of the standards in several tests such as recommended size or durability. For this reason, rice straw pellets were found suitable for their use as fuels whereas the use of rice husk pellets was recommended for other applications as for example adsorbent agents.