EVALUATION OF THE PROCESSING AND UTILIZATION OF INVASIVE HERBACEOUS PLANTS FOR THE PRODUCTION OF BIOFUEL PELLETS

The object of this research was the biomass of two harvested invasive herbaceous plants, and one of pine tree. This plant biomass was harvested, dried and utilized for pressed biofuel production. After harvesting and drying, plant biomass was chopped and milled, and later pressed to cylindrical 6 mm diameter pellets, which were produced using a granulator of low power (120-150 kg h(-1)). After chopped plant milling, it was determined the fractional composition of the mill in all three samples: 60-75% of mill particle size was less than 2.0 mm. So, this milling quality met the requirements for the production of pellets. After analysis of pellet biometrical properties these parameters were measured: the length of produced pellets ranged from 23 to 31 mm, and the diameter was sufficiently stable and varied from 6.0 to 6.2 mm. After investigation of pellet physical-mechanical and elemental properties it was determined that the bulk density of pellets (moisture content 8-9%) reached 1057-1100 kg m(-3). Determined lower calorific value of investigated pellets varied from 16.9 MJ kg(-1) to 19.0 MJ kg(-1). Harmful gas emissions during burning of the tested biofuel pellets were also evaluated. These emissions from the combustion of pellets were sufficiently low and did not exceed the allowed values. Finally, it can be stated, that all investigated granules meet the most important requirements for the quality of biofuel, and it can be prepared and used for energy purposes, for burning in special boilers suitable for granular biofuel.