Avaliação da qualidade da madeira de Coffea arabica L. como fonte de bioenergia

Abstract

EVALUATION OF Coffea arabica L. WOOD QUALITY AS A SOURCE OF BIOENERGYABSTRACT: This work aimed to evaluate, through principal component analysis, the quality of Coffea arabica L. wood obtained from different growth systems and varieties as a source of bioenergy. Wood from three different growth systems (natural, conventional and organic) and two different varieties (Mundo Novo and Catuaí) were used, totalizing six treatments. The contents of elementary components (C, H, N, S and O), ash, lignin, total extractives and holocellulose, basic density, the higher heating value, the lower heating value, as well as the lower and higher volumetric heating values of the analyzed woods were quantified. Principal components multivariate statistical analyses were conducted. The scores of the principal components of interest were determined as a way to divide the woods into groups. Group I was composed by the wood from the organic coffee "Mundo Novo" and natural "Mundo Novo"; Group II by the organic "Catuaí", and Group III by the wood from convencional "Mundo Novo", natural "Catuaí" and convencional "Catuaí". Wood residues from the species Coffea arabica L. showed great potential for energetic use, especially the woods from the conventional systems and the "Catuaí" Variety. Woods from Group III stood out, due to the high volumetric heating values , basic density, lignin content and higher heating value. However, the woods of this group showed high nitrogen content.

How the chemical nature of Brazilian hardwoods affects nanofibrillation of cellulose fibers and film optical quality

“…The oxygen-to-carbon (O/C) ratio was determined for bleached fibers on a dry basis by using a Vario Micro Cube elemental analyzer Leite et al 2014).…”

Characterization of pequi shell (caryocar brasiliense camb.) For its use as a biomass

“…Inferior calorific value was obtained indirectly, using the methodology cited by Leite et al (2014), through Equation (1):Where: ICV = inferior calorific value (kcal/Kg); SCV = superior calorific value (kcal/Kg); H = hydrogen content (%); 600 = heat of condensation of water at 0 °C; 9 = Represents the amount of water (in kilograms) that form by oxidizing one kilogram of hydrogen.…”

“…The figure 1 shows the average value of superior calorific power (SCV) and inferior (ICV), obtained to samples with different moisture content. According to Leite et al (2014) the SCV and the ICV of a determined biomass are the most important physicochemical properties to be considered for the choice of a thermochemical process, because they indicate the quantity of energy released during the transfer of the heat, related to the process efficiency, that is, the higher the SCV, more efficient is the biomass to generate thermal energy (VIEIRA et al, 2013).…”

Balanço de massa, energia e exergia na produção intensiva de frangos de corte.

“…A partir de uma análise elementar, constatou-se que a biomassa da madeira apresenta em sua composição a quantidade de 47% a 54% de Carbono (C), 5,6% a 7% de Hidrogênio (H), 40% a 44% de Oxigênio (O), com 0,1% a 0,5% de Nitrogênio (N 2 ) (SILVA, 2013). Outros estudos apontam 49,31% a 50,07% de C, 6,6% a 6,64% de H, 41,07% a 42,11% de O, 0,39% a 0,52% de N 2 e 1,18% a 1,77% de cinzas com madeira de cafeeiros (LEITE et al, 2014) e 50,3% de C, 6% de H, 43% de O e 0,4% de cinzas para a lenha seca (SARDINHA; MACEDO; MACEDO, 2002). Por sua vez, Marri et al (1982), estudando diferentes tipos de madeira seca, encontraram os valores de 51,8% de C, 6,3% de H, 41,3 de O, e 0,5% de cinzas.…”

“…caracterização da madeira como combustível foi realizada por vários autores, identificando seu poder calorífico e consequente potencial como insumo. Valores de PCS foram encontrados com valores de 19600 kJ/kg para a grimpa de Araucária, 18220 kJ/kg para o pó de Pinus(GABARDO et al, 2011), 19200 kJ/kg para lenha mista com massa específica de 450 kg/m 3 (FUNCK;FONSECA, 2008), 19561 kJ/kg para o PCS e 18067 kcal/kg para o PCI da madeira de cafeeiro(LEITE et al, 2014).Outros autores ainda indicam 18477 kJ/kg para o PCS e 17121 kJ/kg para o PCI da bracatinga seca em estufa (STURION;TOMASELLI, 1990). Segundo alguns manuais de empresas de caldeiras indicam PCI de 15400 kJ/kg (ALFA LAVAL, [s.d.])…”