Investigations of thermal effects during pyrolysis of agro-forestry biomass and physicochemical characterizations of biofuel products

The development of biofuels from waste residues is critical due to higher emissions of greenhouse gases from petroleum and coal and rising energy demand. Converting agricultural and forestry biomass into biofuel products efficiently is a practical approach for simultaneously addressing renewable energy security and waste management challenges. This study examines the physicochemical characteristics of several agro-forestry residues such as camelina meal, mustard meal, flax straw, hemp straw and spruce wood to assess their suitability as feedstocks for pyrolysis to generate biochar, bio-oil and gases. An analysis was conducted to evaluate the influence of temperature (300–525 °C), heating rate (5–35 °C/min) and reaction time (30–75 min) to assess their impact on conversion efficiency and product distribution during pyrolysis. The optimal temperature, heating rate and reaction time for pyrolysis of camelina meal as a model biomass were determined to be 450 °C, 5 °C/min and 30 min, respectively. Physicochemical characteristics of biochar and bio-oil were analyzed to determine the impact of controlled thermal breakdown through slow pyrolysis. As the temperature increased, the calorific value, carbon content and thermal stability of biochar increased due to the removal of volatile matter and the development of aromatic carbon and phenolic features.