The Use of Plant Biomass Pellets for Energy Production by Combustion in Dedicated Furnaces
Andrzej Greinert, Maria Mrówczyńska, Radosław Grech, Wojciech Szefner
Abstract
Biomass combustion is technologically difficult. It is also problematic because of the necessity to manage the ash that is generated in the process. The combustion of biomass pellets is optimum when their moisture is 6–8%. The calorific value of pellets made from straw and willow wood (4:1) was 17.3–20.1 MJ∙kg−1. There were serious problems with burning this material caused by the accumulation and melting of bottom ash on the grate, which damaged the furnace. These problems with optimizing the biomass combustion process resulted in increased CO emissions into the atmosphere. It was shown that pelletization could also be used to consolidate the ash generated during the combustion process, which would eliminate secondary dust during transport to the utilization site. For this purpose, it was suggested to add binding substances such as bentonite and bran. The analysis showed that an optimum material for pelletization should contain, on average, 880 g of ash, 120 g of bentonite, 108 g of bran, and 130 g of water.