Resumo em Inglês:

ABSTRACT There is an increase in researches to create alternative fuels through the use of biomass and agroindustrial lignocellulosic residues. The present study proposes the use of rice bran as source of energy with the potential to enhance bioethanol production. Using different concentrations of cells (1-5 g.L–1) and rice bran (2.5-7.5 g.L –1) with Saccharomyces cerevisiae, a factorial design 22 was carried out. The nutrient source provided by rice bran affects the substrate conversion in product (Yp/s) response in a quadratic form, but its linear form showed no significant effect (α = 0.05). When it comes to means, the best results were obtained for 12 h and for fermentation medium 2 (23.320 g.L–1 of ethanol), which contained the highest rice bran concentration and the lowest initial cell concentration. Medium 3, consisting of 2.5 g.L–1 and 5 g.L –1 of rice bran and cells, respectively, showed the lowest K s (4.434 g.L–1).

Resumo em Inglês:

ABSTRACT The efficient use of biomass as fuel requires prior knowledge of the composition and properties of the material in order to be able to develop technologies for its efficient combustion while ensuring that emissions of pollutants remain within acceptable limits. Therefore, the analysis of the physical and chemical properties of these materials is essential in order to evaluate their potential for energy purposes. Given the need for improved understanding of biofuels, this study aimed to characterize biomass waste obtained from the manufacturing process of wood panels and urban waste for the production of solid biofuels. Biomass wastes were characterized in terms of their physical and chemical properties. Wastes that presented the poorest qualities for use as fuels were eucalyptus bark, industrial waste, and sweepings, which had high ash contents and low calorific values. The remaining wastes showed satisfactory characteristics for use as solid biofuels.

Resumo em Inglês:

ABSTRACT Different classes of solvents such as mineral acids and ionic liquids have proved to be capable of disrupting hydrogen bonds among different polysaccharide chains. Recently, a specific family of proticionic liquids (PILs) has been developed with functionality in various industrial applications, adding to the benefits and advantages of their use, since they are absent of aromatic or halogenated molecular structure, making them structurally free of toxicity. This work aimed to verify the influence of proticionic liquids 2-HDEAS, 2-HEACi, 2-HEAL impregnated in the Prosopis juliflora (mesquite) biomass, through the thermogravimetric analysis of macrocomponents hemicellulose, cellulose and lignin. Tests were performed in a simultaneous thermogravimetric analysis equipment under inert atmosphere, 100 mL/min of nitrogen, and 10 °C/min heating rate. It was verified that all PILs present great potential in the degradation and dissolution of the macrocomponent structure of Prosopis juliflora.

Resumo em Inglês:

ABSTRACT This study aimed to determine the chemical and energetic composition of Brazil nut waste in the city of Castanhal-PA. Some of the material was crushed, sifted and stored for acclimatization and analysis. Molecular and immediate chemical analyses were performed on the raw material according to NBR standards. Another part was charred in Muffle furnace, with heating rate of 1.67 °C.min-1 and temperature of 450 °C for 60 minutes. For biomass, 55.76% of lignin and 2.61% of minerals were found. Means of 65.67% for volatiles were also found; 2.08% of ashes and 21.64% of fixed carbon. In the elementary, means of 53.54% of carbon and 0.11% of sulfur were found. For charcoal, 25.81% of volatiles were found; 1.76% of ashes and 67.50% of fixed carbon. Residues have high levels of lignin, fixed carbon and low ash contents, demonstrating potential for direct burning for energy, charcoal, activated carbon and biochar.

Resumo em Inglês:

ABSTRACT This work aimed to chemically and energetically characterize palm waste in the municipality of Igarapé Açú-PA. The residue was crushed, sieved and acclimated up to 12% of humidity. Chemical analyses were performed in the fresh material, according to NBR standards. Part of the residue was transformed into charcoal at 450 °C, with heating rate of 1.67 °C.min-1 and residence time of 30 minutes. Elementary analysis (CHNS-O) was carried out in the fresh and carbonized material. For biomass, means of 32.67% of lignin and 2.58% of minerals were found. Means of 79.71% for volatile materials and 9.85% for fixed carbon were also found. In the elementary analysis, mean values of 53.79% for carbon and 0.7% for sulfur were found. Palm biomass residues presented high fixed carbon, structural carbon and lignin levels, thus presenting potential to be used in the direct production of energy, activated carbon and also biochar.

Resumo em Inglês:

ABSTRACT The tobacco production requires annually a large volume of firewood used in the cure process of tobacco leaves, representing up to 10% of its production cost. An alternative is the use of agroindustry residues, such as sawdust or pellets. The objective of this study was to analyze the consumption and to characterize forestry biomass used in the tobacco cure process in farmers from Candelária, Southern Brazil, aiming the culture energetic efficiency. Forestry biomass consumption, residues formation after combustion and biomass quality were verified. In terms of available energy, the consumption for each kilogram of dry tobacco was 77.23 MJ for firewood, 61.40 MJ for sawdust and 37.51 MJ for pellets. Pellets presented the best physicochemical characteristics for use as energy, as well as the lowest consumption and the lowest organic fraction present in combustion residues.

Resumo em Inglês:

ABSTRACT The aim of this study was to apply geostatistics to predict the spatial pattern of variations in moisture content of eucalyptus wood chip piles to generate subsidies for adequate sampling and material handling. Wood chip piles were installed in three different storage cycles using newly cut material for 7, 30, and 60 days. Sampling was performed in axial (top, middle, and base) and lateral positions, so that all samples were georeferenced in relation to the distance from the ground and the center of the pile. Moisture values were submitted to geostatistical analysis and kriging. The results confirmed the spatial dependence of moisture content over the piles stored at 7 and 30 days; however, the effect of rainfall was crucial to reduce the spatial dependence of moisture content. The results showed that geostatistics is a useful tool for the creation of reliable sampling protocols.

Resumo em Inglês:

ABSTRACT The objectives of the present work were to determine the properties of wood and charcoal from Eucalyptus clones and assess impacts of charcoal features on the CO2 gasification reactivity and to compare with coke reactivity. Gasification reactivity was performed using charcoal particles in a furnace setup at 820 °C, under CO2 atmosphere. The results show that there is wood variability among evaluated clones and strong correlations between wood and charcoal properties. All charcoals had higher reactivity in comparison to coke. The decrease in porosity and increase in apparent density in Eucalyptus wood led to a slight decrease of CO2 gasification reactivity. In addition, strong positive correlation between charcoal reactivity and potassium concentration (K) was found.

Resumo em Inglês:

ABSTRACT This work aims at the physicochemical characterization of four species: Eucalyptus sp, Pinus sp, Citrus sinensis and Hevea brasiliensis for use in ceramic furnace. Immediate analysis, chemical analyses were carried out (total extractives, Klason lignin, holocellulose and alpha-cellulose content). Results were applied to ANOVA and Tukey for statistics. The ash content of Pinus sp was 1.60%, for volatile material content Eucalyptus sp presented 83.61%, for fixed carbon values, Citrus sinensis presented 20.03%. Chemical analyses in the total extractive content, Citrus sinensis presented 21.76%, Klason lignin content, Pinus sp had 39.24%, Eucalyptus sp 60.29% had the highest holocellulose and alpha-cellulose, which was 42.72%. Pinus sp sample was the one with the highest heating value of 20.090 J/g. According to results obtained in the analyses, it is possible to conclude that all species have potential for applications in ceramic furnace.