Seleção de espécie, temperatura e tempo de carbonização na produção de carvão vegetal com resíduos madeireiros da Amazônia

Abstract

A atividade florestal na Amazônia gera grandes quantidades de resíduos, desde a exploração florestal até o beneficiamento das toras, sendo a carbonização uma alternativa potencial para mitigar este passivo. Entretanto, a diversidade de espécies e a carência de informações sobre parâmetros ideais de carbonização dificultam a operação dos fornos. Nessa pesquisa são avaliados os efeitos da espécie e parâmetros de carbonização sobre a qualidade energética na conversão de resíduos de indústria madeireira em carvão vegetal. O material de estudo foi proveniente do município de Paragominas, PA, coletando-se amostras das três espécies mais comercializadas, Handroanthus serratifolius (Vahl) S.O., Hymenolobium petraeum Ducke e Enterolobium schomburgkii (Benth.) Benth. As carbonizações foram realizadas em forno mufla, com temperaturas de 500 °C e 600 °C e patamar final de 30 min e 60 min. Os parâmetros espécie e temperatura foram os que apresentaram efeito significativo, exercendo maior influência na produção e na qualidade do carvão vegetal. O tempo no patamar final de carbonização não influenciou as variáveis. O aumento da temperatura provocou redução no rendimento gravimétrico. Os resíduos madeireiros das três espécies apresentaram características de elevada qualidade para produção de carvão vegetal.

The quality of artisanal charcoal sold for domestic use in Tucuruí municipality in the Brazilian Amazon

“…Figure 2 shows that up to 85% of the released energy can be explained by the concentration of fixed carbon. With respect to the negative correction between FCC and VMC, Figure 3 shows that 79% of the reduction in FCC is attributable to VMC, which is consistent with the findings reported by Anater et al ( 2019) and Silva et al (2020). However, the ratios and percentages reported by these authors are higher than those determined in the present study.…”

“…With respect to AC, we detected no significant differences among the charcoals produced in the different neighbourhoods, although the mean percentage was found to be higher than the one reported in the literature for charcoal prepared from tropical species (Reis et al, 2015;Oliveira et al, 2019;Silva et al, 2020), but lower than the percentage of AC in charcoal sold in some south and southeast locations (Oliveira et al, 2015;Brand et al, 2015;Anater et al, 2019).…”

“…We found that the charcoals produced in neighbourhoods 1 and 5 have lower and higher VMCs, respectively, with higher percentages those reported by Reis et al (2015); Silva et al (2020) for charcoals produced in the municipalities of Altamira and Paragominas, respectively, both in Pará. In general, there tends to be a high degree of variability in the VMC of charcoals produced in Brazil.…”

“…Oliveira et al (2019) and Silva et al (2020) also observed that the sizes of pieces in the oven strongly influence the quality of the charcoal produced. Oliveira et al (2019) also pointed out that the combustibility, maximum temperature and time in the oven also affected the quality of the resulting charcoal, and suggested that smaller pieces in the upper part of the oven and larger pieces in the lower part results in the best energy generation start and heating efficiency.…”

“…Given the species diversity in the region, it is necessary to seek knowledge regarding the behaviour of native wood during carbonization, thereby enabling the characterization of charcoal originating from forest exploitation and timber industry waste. With respect to Amazonian native wood, there has been little progress from a technical–scientific point of view, as highlighted by the research of Oliveira et al (2019) and Fortaleza et al (2019), who verified the quality of the charcoal sold in southeast and northeast Pará, respectively; by Reis et al (2015), who compared sawmill waste charcoal sold in the municipality of Altamira, PA, with babaçu coconut charcoal; and by Silva et al (2020), who analysed commercial charcoal from the State of Amapá. Studies have also been conducted in other Brazilian States with the aim of verifying the quality of the produced charcoal, such as the studies by Rosa et al (2012), Oliveira et al (2015), Brand et al (2015), and Anater et al (2019).…”