Balanço de massa da carbonização e propriedades físico-químicas de carvões vegetais de coprodutos do manejo florestal sustentável da Amazônia

Abstract

The co products or residues from sustainable forest management in the Amazon are promising for the production of steel charcoal. However, there is a gap in the literature on the performance of charcoal from these co-products for steel and/or industrial purposes. The objective of the research was to analyze the influence of the quality of residues from sustainable forest management in the Amazon and the carbonization temperature on the physical-chemical properties of charcoal destined for steelmaking purposes. From the residues, the chemical, physical and energetic characteristics of the wood were determined. The carbonizations were carried out in the laboratory with four final temperatures (400, 500, 600 and 700°C). The gravimetric yields of the carbonization process were evaluated. The charcoal produced was characterized by apparent relative density, immediate chemical composition, energetic properties, and the specific consumption (CE) was calculated. The results showed significant variations for basic wood density (0.42-0.99 g/cm³), lignin total (22.78-40.68%), acetone-soluble extractives (0.25-8.08%), total extractives (2.45-12.01%), ash (0.36-1.91% ) and calorific value (19.0 - 20.57 MJ/kg). Furthermore, a wide variation was observed for the gravimetric yield in charcoal (31.66-39.41%). The apparent density of charcoal varied from 0.37 g/cm³ to 0.66 g/cm³. The EC ranged from 2.60 m³/ton to 7.09 m³/ton. For the higher calorific value of charcoal, there was an interaction between species and temperature, with the highest values being found at higher temperatures. Energy density was greater at higher temperatures, ranging from 11.53 to 20.99 GJ/m³. The study found that analyzes of chemical and physical composition are extremely important for the classification of raw materials for charcoal production. It was observed that temperatures between 400 and 500°C are suitable for charcoal production. Waste from the species D. excelsa and M. elatawere considered more suitable for the production of biothermal reducer, as they produced denser coals with better energetic properties. The study showed that the properties of wood are more relevant than the pyrolysis temperature, since high yields were found in the carbonization of woody residues from M. elata and D. excelsa at temperatures between 600 and 700°C.