Quality and energetic evaluation of the charcoal made of babassu nut residues used in the steel industry

Abstract

Brazil is the only country in the world that uses large scale charcoal in steel-making blast furnaces. Meantime, the monoculture plantations of Eucalyptus are not able to meet the demand for charcoal from the steel industries.Therefore, research is necessary, in order to use lignocellulosic residues for the production of charcoal with technological properties which are suitable for the reduction of iron ore. Given the above, the objective of this study was to evaluate the quality of charcoal which was made with babassu nut shell and designed for utilization in the steel industry in the function of the final carbonization temperature. All three layers of babassu nut shell (epicarp, mesocarp and endocarp) were used together. The initial temperature of the test was 100°C and the final temperatures were: 450°C, 550°C, 650°C, 750°C and 850°C. For the charcoals produced, the following properties were determined: apparent relative density, energy density and fixed carbon stock, in addition to chemical compositions (immediate and elemental) and heating values (higher and lower). Charcoal made of babassu nut shell showed high values of apparent density and energy density, and has a potential to replace coal and wood charcoal in the steel industry. The effect of the final carbonization temperature was expressed for all characteristics evaluated, except for the nitrogen content. Babassu nut shell must be carbonized at temperatures higher than 550°C, so that the charcoal produced can be used in steel-making blast furnaces.Index terms: Alternative biomass, renewable energy, bio-reducer, carbonization. RESUMOO Brasil é o único país no mundo que utiliza, em grande escala, o carvão vegetal nos altos fornos siderúrgicos. Contudo, os plantios homogêneos de Eucalyptus não são capazes de suprir a demanda de carvão vegetal das siderúrgicas. Por isso, são necessárias pesquisas visando ao aproveitamento de resíduos lignocelulósicos, para a produção de carvão vegetal com propriedades tecnológicas adequadas à redução do minério de ferro. Dessa forma,objetivou-se, neste trabalho, avaliar a qualidade do carvão vegetal da casca do coco babaçu, destinado ao uso siderúrgico, em função da temperatura final de carbonização. Foram utilizadas, conjuntamente, as três camadas constituintes da casca do coco babaçu (epicarpo, mesocarpo e endocarpo). A temperatura inicial do ensaio foi de 100ºC e as temperaturas finais foram de 450ºC, 550°C, 650°C, 750°C e 850°C. Para os carvões produzidos, foram determinadas as seguintes propriedades: densidade relativa aparente, densidades energéticas e estoque de carbono fixo, além das composições químicas (imediata e elementar) e os poderes caloríficos (superior e inferior). O carvão vegetal da casca do coco babaçu apresentou elevados valores de densidade aparente e de densidade energética e é passível de substituir o carvão mineral e o carvão vegetal de madeira na siderurgia. O efeito da temperatura final de carbonização foi pronunciado para todas as características avaliadas, com exceção do teor de nitr...

Combustion of Biomass and Charcoal Made From Babassu Nutshell

“…The higher average rate of combustion of the charcoal produced at 850°C, in relation to the charcoals obtained at the temperatures of 650°C and 750°C, can be explained by the lower ash content of the charcoal produced at high temperature (PROTÁSIO et al, 2014b).…”

“…Therefore, studies on the use of alternatives biomass, for example, the babassu nut waste, have great potential to be used for energy generation (PROTÁSIO et al, 2014a(PROTÁSIO et al, , 2014b(PROTÁSIO et al, , 2014cREIS et al, 2015). Babassu nutshell showed a high basic density and a suitable lignin content for the sustainable production of bioenergy and charcoal (PROTÁSIO et al, 2014a).…”

“…In addition, the charcoal of babassu nutshell has high values of apparent density and energy density, possesses chemical and energetic properties suitable for steel use, and can be considered as a potential replacement of wood charcoal (SILVA et al, 1986;EMMERICH;LUENGO, 1996;PROTÁSIO et al, 2014b). The charcoal from babassu coconut can be used for direct heat generation in other industrial segments; however, their combustibility or combustion performance should be studied.…”

Effect of Extractives and Carbonization Temperature on Energy Characteristics of Wood Waste in Amazon Rainforest

“…The higher the final pyrolysis temperature, the higher the concentration of carbon in charcoal (PROTÁSIO et al, 2014).…”

“…Different authors also found a positive relationship between the heating value and the final carbonization temperature (TRUGILHO; SILVA, 2001;PROTÁSIO et al, 2014). The two principal components account for approximately 81% of the variance in the original data; thus, it was decided to use only these two principal components for principal PCA.…”