Kraft lignin fractionation by organic solvents: Correlation between molar mass and higher heating value.

The new concept of integrated biorefineries has significantly changed pulp and paper industries. Lignin, which until then was only burned to generate energy, is now an important raw material for new products production. Kraft lignin (KL) fractions obtained by sequential fractionation with five organic solvents. This sequence allows to extract fractions from lower molar mass to higher molar one, resulting in more homogeneous samples. Lignin's fractions were characterized by FTIR, GPC, TGA and Higher Heating Value (HHV). HHV for KL was 24966, the lowest being 17,891 (F5) and the highest being 27051 J/g (F1), inversely proportional to the molar masses of fractions. This is a very important result indicating that the lower HHV fractions can be used for certain applications, such as antioxidants, additives, polymers, among others, adding value to kraft lignin. Fractions with higher HHV could be used for energy generation in the cellulose paper industry.

Forest harvest byproducts: Use of waste as energy.

Forest harvest waste is an attractive biomass feedstock for biofuel production. However, for better use it is necessary to understand the physical-energetic characteristics of the biomass which composes the waste. Therefore, this study aimed to evaluate the bark, wood and tree top characteristics from Eucalyptus urophylla × Eucalyptus grandis (called urograndis) and Acacia mangium harvest wastes. These species present fast-growing characteristics. The evaluations were carried out with waste generated in the forest harvest in central Brazilian plantations. Three fractions were studied: the Top, Wood and Bark. The energetic and physical characteristics of wastes and briquettes were determined. The top and bark of these species are not yet recognized for their energy potential. A. mangium presented better energetic and physical characteristics than urograndis, with a higher mean of fixed carbon (20.84%), a high heating value (20.34 MJ kg-1), as well as high bulk and energy density (272.66 kg m-3 and 5599.00 MJ m-3). A. mangium bark and urograndis tree tops were the fractions with the best characteristics for energy purposes. Bark, wood and tree top waste generated after urograndis and A. mangium forest harvesting can be used as byproducts for energy purposes in their fresh form (as collected in field) or as briquettes, presenting an alternative for the waste.

Thermal degradation of calcium and sodium alginate: A greener synthesis towards calcium oxide micro/nanoparticles.

Processes for nanoparticle synthesis often use toxic solvents under aggressive conditions. A greener alternative is the burning of self-organized alginate systems. We followed the influence of the CaCl2 concentrations during gelation of sodium alginate and the heating rate on the synthesis of nanoparticles by the combustion method using TGA as a reactor vessel. Samples were collected after each main process of mass loss and characterized using the Scanning Electron Microscopy, Infrared Spectroscopy, and X-ray Diffraction. Samples treated at 50 °C·min-1 presented porous structures at temperatures more than 500 °C lower than the treatments at 10 °C·min-1. All calcium alginate samples presented changing from a predominantly amorphous to crystalline structures such as Ca(OH)2, CaCO3 in the calcite phase and CaO as a function of the temperature, while sodium alginate produced mainly Na2CO3, NaOH and NaO. We observed two main correlations: 1) between the porosity and the heating rate, and 2) between the formation of crystalline structure in intermediate temperatures and the CaCl2 concentration in the gelation step.

Production and characterization of bamboo pellets / Produção e caracterização de pellets de bambu

Agroforestry biomass is a great energy alternative, with potential to produce pellets and briquettes. The objective of this study was to assess the potential of using the biomass of bamboo species to produce pellets. Mature culms of the species Bambusa vulgaris var. Vitatta, Dendrocalamus asper and Bambusa tuldoides were used, in addition to wood discs of 6 year-old hybrids of E. urophylla x E. grandis for comparative purposes. Biomass was characterized by the bulk density, proximate analysis, calorific value and energy density. Pellets were characterized (moisture content, length, diameter, durability, bulk, apparent and energy density) after production. All the characteristics of bamboo and eucalyptus pellets met the quality specifications required in international product marketing standards, except for the ash levels. The species Bambusa vulgaris var. vitatta, Dendrocalamus asper and Bambusa tuldoides had energy characteristics that indicate its potential for being used as an energy source in the form of pellets.

A biomassa agroflorestal é uma ótima alternativa energética, com potencial para produzir pellets e briquetes. O objetivo deste estudo foi avaliar o potencial de uso da biomassa de espécies de bambu para produzir pelotas. Colmos maduros da espécie Bambusa vulgaris var. Vitatta, Dendrocalamus asper e Bambusa tuldoides foram utilizado, além de discos de madeira de híbridos de E. urophylla x E. grandis de 6 anos para fins comparativos. A biomassa foi caracterizado pela densidade a granel, análise aproximada, valor calorífico e densidade de energia. Pellets foram caracterizados (teor de umidade, comprimento, diâmetro, durabilidade, volume, aparente e densidade de energia) após a produção. Todas as características de pelotas de bambu e eucalipto atendem às especificações de qualidade exigidas pelas normas internacionais de comercialização de produtos, com exceção dos níveis de cinza. As espécies Bambusa vulgaris var. vitatta, Dendrocalamus asper e Bambusa tuldoides tinham características energéticas que indicam o seu potencial para ser utilizado como fonte de energia na forma de pellets.