Environmental hotspots in the life cycle of a biochar-soil system

A life cycle assessment was conducted to study the environmental effects of a biochar-soil system and to identify the main environmental hotspots. Six scenarios were evaluated, which included the production of biochar from agricultural and forestry residual biomass pyrolyzed at 300, 400, and 500 °C, using a functional unit of 1 t of produced biochar. Modeling of the system and evaluation of impacts were performed using SimaPro selecting impact categories of climate change, human toxicity, freshwater eutrophication, and fossil depletion. According to the results, the climate change impact category presented the greatest relative importance in the life cycle of biochar, with greenhouse gas emission reductions of up to 2.74 t CO2 eq t−1 biochar when the biochar applied to soil is produced from forestry residual biomass at 500 °C.