Assessment of Quality and Combustion Characteristics of Briquettes Derived from Giant Hogweed Biomass

The presence of Giant Hogweed (Heracleum mantegazzianum) in agricultural landscapes raises concerns due to its impacts on agroecology. Physically removed biomass can serve as a feedstock for solid biofuel, representing a viable strategy reducing reliance on herbicides. Giant Hogweed’s bioenergy potential is currently underexplored, particularly regarding its seasonal variations in properties and the environmental impacts resulting from its use as a biofuel. This study assessed the processability of Giant Hogweed biomass into briquettes, to determine their mechanical durability and to evaluate their basic emission characteristics during combustion in a device commonly used at the household level. Biomass was sampled at two specific stages of plant development for a comparative study of briquette properties. For both summer- and autumn-harvested biomass, a high mechanical durability of the produced briquettes, approximately 97%, was achieved. Only carbon monoxide emissions from summer-harvested biomass exceeded the limits; nitrogen oxides concentrations were within the limits for both. Thermogravimetric analysis and differential scanning calorimetry revealed decomposition patterns. Autumn-harvested biomass showed better potential for briquetting, highlighting the advantages of later collection. The findings demonstrate the potential of plant and applied processing technology for valorisation as a solid biofuel, while certain aspects still need consideration.