Biochar from Acai agroindustry waste: Study of pyrolysis conditions.

The production chain of Acai (Euterpe oleracea Mart) has a high economic representativeness in the Brazilian Amazon. However, wastes generated from the processing of the fruit has been deliberately discarded in the environment, causing health risks to the population due to environmental contamination or the proliferation of disease agents. Thus, the production of biochar arises as an alternative to the irregular disposal of these residues. The objective of this work was to evaluate the conditions (temperature and residence time) to produce biochar from Acai processing residues and its potential for use as soil conditioner in the Amazon region. Acai seeds were carbonized using the process of muffle pyrolysis at different temperatures and residence times. Biochars were evaluated for their physical and chemical properties and hydrophobicity. The temperature had a greater influence than the residence time for most parameters. Higher values of pH, higher recalcitance and greater potential for water retention were observed for the biochar produced at temperatures of 600 and 700 °C. At lower temperatures (300 and 400 °C), a greater yield was observed, however, in this condition, the material presented an extremely hydrophobic character. By considering the favorable agronomic characteristics of biochar, the temperature of 600 °C and residence time of 60 min are the most suitable conditions for the production of biochar from Acai seeds.