Bioenergetic properties and a practical opening technology of the Brazil nutshell.

Abstract

Brazil Nut is one of the main non-timber exports from the Amazon, with 85% of the fruit consisting of residues from its harvest and debarking yearly available. The Amazon communities that harvest the nuts could benefit from its sustainable use. This work comprises three aims and stages: (i) to review current research and technologies for the sustainable potential of Brazil Nut residues, (ii) to evaluate the energy potential of biomass and charcoal from both fresh and degraded Brazil Nutshell (BNS) mesocarp and (iii) to design and produce a device capable of removing the Brazil Nuts from the fruit easily. Brazil Nut residues are suitable for conversion into many bioproducts and biofuels. However, carbonization is applied nowadays, where the current applied method leaves a lot of residues partially carbonized, which decreases BNS market value. This undesired result is mainly because the shape of residues harms carbonization. Since BNS has remarkable physical properties and strength, cutting them into a suitable shape for traditional carbonization is difficult. Therefore, a device has been designed for a quick, safe, and efficient cutting of the BNS for later carbonization without harming the edible nuts. The device is basically a modification of the Miter Saw Vonder Sev857 to hold and cut open Brazil nuts. The device was able to cut the shells into equal halves. Fresh BNS mesocarp samples presented a net calorific value of 4,797 kcal/kg and basic density of 1 g/cm3, while degraded BNS mesocarp samples showed a net calorific value of 4,600 kcal/kg and basic density of 0.84 g/cm3. Thermogravimetric analysis indicated that fresh and degraded BNS mesocarp samples are suitable for carbonization and have energy potential, but their thermal behavior differed. The charcoal produced at T = 400 °C from degraded BNS showed 43.2% of volatile matter, 3.5% of ash, and 53.3% of fixed carbon, while fresh samples showed 18.63% of volatile matter, 1.23% of ash, and 80.14% of fixed carbon. It was concluded that degradation in the forest floor decreases the bioenergy potential of Brazil nut shells, especially by altering their chemistry.