Search

Copyright of Floresta is the property of Revista Floresta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Briquetting is a form to aggregate value in the biomass production chain, to re-use sustainably waste and to provide high-quality solid biofuels, as well as to enable the development of the energy market. The aim of this study was to evaluate the potential of the production of briquettes from epicarp waste of macauba fruit and verify the influence of different temperatures and compaction pressures on the chemical, physical, and mechanical characteristics of the briquettes. The epicarp was reduced to particles and, then classified, dried, and characterized for their physical and chemical properties. The briquettes were produced by using compression pressures of 62, 83, and 103 bar and temperatures of 90 and 120 °C. The effect of these factors upon the variables studied was verified through regression analysis. The increase of pressure and temperature contributed to greater mass loss of the briquettes. Apparent density and energy density increased due to temperature rise. High values of energy density were obtained, which demonstrates the potential of the macauba fruit epicarp to produce briquettes for generation of thermal energy. [ABSTRACT FROM AUTHOR]

The combination of pelletization and torrefaction allows for obtaining pellets with higher energetic density. Thus, biomass becomes more attractive and usable for energetic purposes, and therefore, knowing the chemical properties becomes important to guarantee the quality of the torrefied pellets for fuel. The objective of this study was to evaluate the effect of torrefaction of Pinus sp. pellets on their chemical properties. The wood was previously transformed into particles and dried to 16% moisture content for further pelleting. For the torrefaction, the pellets were dried to 0% moisture content and subjected to heat treatment in a screw type reactor at the temperatures of 210, 250, and 290 °C and the times of 10, 20, and 30 minutes. In order to determine the chemical properties, the structural chemical composition, immediate chemical composition, elemental composition, and thermogravimetric analysis were performed. The torrefaction promoted significant changes in the chemical properties of Pinus sp. pellets, especially regarding the proportional increase of carbon content in detriment to oxygen reduction, increase of the thermal stability, and proportional increase of the lignin content by the reduction of the hemicelluloses. This improves the energetic quality of the biomass and turns it into a more competitive fuel when compared to fossil fuels. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of genetic material and the planting location on charcoal produced from eucalyptus wood from short rotation systems. It was evaluated five clones of Eucalyptus sp. from three municipalities of the state of Minas Gerais. Wood chip samples were charred in electric oven muffle, with heating rate of 1.67 °C/min and evaluated the following parameters of the resulting carbon: Yield charcoal, Proximate composition (fixed carbon, volatiles matter and ash), Density apparent and Higher heating value. Was noted that both variables - genetic material and planting location - had a significant effect on yield charcoal, in proximate composition and higher heating value. Already the coal density was not affected by any of the two variables. The yield and density were below the values reported in the literature for coal produced under the same laboratory conditions, with wood from conventional systems with older cut. In general, it can be observed the importance of assessing the potential for the production of coal individually. Furthermore, it was shown that clones of Eucalyptus spp. from short rotation systems are less suitable for charcoal production than conventional systems. [ABSTRACT FROM AUTHOR]

The pellets are becoming an important renewable source of energy for industrial and domestic use. The consumer market is increasingly demanding in terms of product quality and this may be improved through the use of various additives, such as kraft lignin. The objective of this study was to evaluate the quality of eucalyptus pellets produced with the addition of different percentages of kraft lignin. The raw material used for production of pellets was wood with bark of an Eucalyptus grandis x E. urophylla clone, with approximately five years of age, obtained from commercial planting, and 10% of waste of eucalyptus harvest (tops, leaves and branches). Excluding the control (0% lignin) was added 1, 2, 3, and 5% kraft lignin, relative to the dry mass of raw material. The pellets were produced in a laboratory pelletizer with a horizontal circular array. The following properties of the pellets were evaluated: moisture content, gross and net calorific value, unit density, bulk density, energy density, ash content, length and diameter, hardness, mechanical durability and fines content. The addition of kraft lignin contributed to improving the pellets physical and mechanical properties, as regards the density, mechanical durability, fines and hardness. The addition of lignin caused the elevation of the levels of ash and moisture content of the pellets. It is concluded that addition of lignin to pellet production is feasible, since lignin is used with lower contents of ash and moisture. [ABSTRACT FROM AUTHOR]