Caracterização físico-química de biocarvões com potencial para condicionador de solo

Abstract

Biochar is a product obtained from the pyrolysis of different raw materials, which, depending on its composition and preparation temperature, has a high concentration of carbon, porosity, specific surface and minerals, which highlights it as an input with potential for various applications . The objective of this study was to develop biochars from the pyrolysis of sisal residue, neem, jurema and jurubeba biomass and evaluate their physicochemical characteristics as potential soil conditioners. The biomasses were collected and left to air dry, in small pieces, before carbonization. The pyrolysis process was carried out in an iron furnace, with the adaptation of a 200L drum, which had a chimney attached to its upper part and a 50L drum was inserted inside with the function of storing the biomass to be pyrolyzed. For each type of biomass, pyrolysis was carried out in five repetitions. The temperature, carbonization time, physicalchemical attributes of biomass and biochars were evaluated. The direct influence of the pyrolysis temperature and time and also of the raw material on the production of biochars was observed. The highest pyrolysis efficiency was for sisal residue with 60.2% of its biomass transformed into biochar. There was an increase in pH after carbonization of all biomasses and the highest value was observed for neem biochar with pH 10. Jurema's biomass and biochar samples stood out with the highest percentage of total organic matter with 94% and 81 % and highest nitrogen content with 1.95% and 2.66%, respectively. Jurubeba biomass and biochar obtained the highest potassium value with 3.63% and 1.88%, respectively, in addition to having the highest water retention capacity with 124% of available water, in relation to its mass. The biomass of sisal residue presented a high value of manganese with 294.2 mg kg-1, Zinc 84.40 mg kg-1 and Calcium 5.92%, while in biochar, there was an increase for these minerals with values of 334.0 mg kg-1, 134.10 mg kg-1 and 10.61%, respectively. It is concluded that different biomasses have potential for producing biochars, and their quality depends mainly on the pyrolysis process and the source of biomass used. The biochars analyzed presented physical and chemical characteristics with the potential to be soil conditioners.