Search

Abstract This research aimed to evaluate the production of charcoal and wood vinegar in a mini-rectangular kiln equipped with a condenser and vertical smoke burner. The kiln had a chimney, a condenser and a vertical smoke burner. The logs were 0.90 m long and had characterized. Ten carbonization runs were conducted to evaluate the kiln’s performance, determining the gravimetric yields in charcoal, wood vinegar, and gases. The carbonization process took three days to conclude and four days to cool the charcoal. The results showed that the average yields for charcoal, wood vinegar, and gases were 34.0, 31.2, and 34.8%, respectively. The charcoal produced, despite the use of moderate-density wood, demonstrated favorable characteristics. The moisture content, ash content, volatile materials, and higher calorific values all fell within the ideal ranges. This, coupled with a good yield, confirms the technical viability of the system as an alternative for small producers.

ABSTRACT The thermal modification of wood is a process that alters its chemical composition, aiming to improve technological properties such as dimensional stability, reduction of equilibrium moisture content, homogeneity, or color. In this context, this study aimed to evaluate the colorimetry and chemical properties of the wood of Parkia pendula (angelim-saia) and Simarouba amara (marupá) that was thermally modified by different methods. Three treatments were evaluated: T1 (pre-treatment in an oven for one hour at 120 °C and treatment in an oven at 180 °C for three hours); T2 (pre-treatment in an autoclave at 125 °C for three hours under 1.2 kgf cm-2 and treatment in an oven at 180 °C for three hours); and T3 (without pre-treatment, with sample treatment in vegetable oil). The thermally modified wood was evaluated in relation to untreated wood for structural chemical composition (extractives, lignin, holocellulose and ash content), colorimetric parameters defined through the CIELAB (Commission Internationale de l´Eclairage) system and total color variation. We detected a significant increase in extractives content and a decrease in holocellulose and lignin content in T3 for both species, which can be explained by the impregnation of oil in the wood samples. The thermal modification caused the surface darkening of the wood of both species, which was more pronounced in P. pendula. Despite the colorimetric change, there was no chemical damage to the wood.

Abstract Knowledge of the characteristics and durability of every wood species is essential so it can be better directed for the correct harnessing. In a wood rot field test, this work aimed to determine the natural durability of timber species from the Brazilian dry forest, Mimosa tenuiflora and Mimosa caesalpiniaefolia . The slats were buried in the ground up to half their length and distributed in the field according to a completely randomized experimental design. Annual assessments were performed to determine the deterioration rate. Furthermore, mass loss and condensed tannin content were quantified. The condensed tannin content found for the species was 4.40% for M. caesalpiniaefolia and 3.99% for M. tenuiflora . The results of 3 years of evaluation of the test make it possible to understand that both species presented durable wood, where M. caesalpiniaefolia presented a deterioration rate of 77.27%, while M. tenuiflora presented 66.27%, making them of high natural durability.

EXTRATO O presents trabalho teve por objetivo estudar a variação, no sentido medula-casca e ao longo da altura da árvore, do teor de extrativos solúveis em água quente e água fria, das madeiras de Eucalyptus microcorys F. Muell. e Eucalyptus pilularis Sm. com idades de 20 anos, provenientes de um plantio da UFV. As amostras foram obtidas de 3 em 3 cm, no sentido medula-casca, e de 2 em 2 metro, ao longo da altura, de três árvores de cada uma das espécies. O teor de substâncias solúveis em água quente e em água fria variou, significativamente, na árvore, com uma tendência de aumento da medula para o cerne periférico. Nas camadas mais internas, também se pôde observar aumento dos teores no sentido base-topo. Nas camadas mais externas, o teor era constante mas, às vezes, descrescente. Os menores teores de extrativos foram observados na madeira do alburno.

Background: The search for substances that can overcome microorganisms’ resistance and enhance the antimicrobial activity of given products has attracted the attention of researchers. Eucalyptus wood vinegar (WV) is a promising product for developing alternative antimicrobials. Objectives: This study aimed to evaluate whether the production of WV in the co-pyrolysis of eucalyptus wood with aromatic herbs would incorporate compounds from them into WV and if that would enhance its antimicrobial action. Methodology: WV was produced alone and through co-pyrolysis with marjoram (Origanum majorana), Peruvian oregano (Origanum vulgare), rosemary (Salvia rosmarinus), thyme (Thymus vulgaris), and Turkish oregano (Origanum onites) at a proportion of 25% of herbs to the bone-dry wood weight. The antimicrobial effects were assessed against strains of gram-negative and -positive bacteria, and Candida glabrata. Microorganisms’ colony growth in agar had their absorbances recorded after inoculation and incubation. Chemical characterization of the new products was performed by gas chromatography and mass spectrometry (GC/MS). Results: After coproduction, there were relevant chemical changes concerning the original WV. Thymol, for instance, was incorporated into the WV through co-pyrolysis with marjoram, Peruvian and Turkish oregano, and thyme. The coproducts were more efficient than the WV produced only with wood, with thyme-incorporated products having the highest efficiency. This can be attributed to the increase and incorporation of the substances after coproduction, and particularly the role of thymol in enhancing the antimicrobial action. Conclusion: Given the results, the co-production of WV with eucalyptus wood and aromatic herbs has the potential to provide alternative antimicrobial products.

RESUMO O objetivo deste trabalho foi avaliar adesivos à base de creosoto vegetal e creosoto livre de nãofenólicos (NF). O creosoto foi extraído com n-hexano para retirada dos NF. Amostras de creosoto e de creosoto extraído foram desmetiladas e usadas na síntese de adesivos. Foi montado um experimento envolvendo dois tipos de adesivos à base de creosoto desmetilado, com NF e sem NF. Foram coladas lâminas de Pinheiro do Paraná, avaliando-se a resistência da linha de cola no cisalhamento em tração, em condição seca e úmida. Os resultados mostraram que os NF não influenciam negativamente a resistência da linha de cola.

ABSTRACT This research aimed to evaluate the effect of thinning on the wood volumes per hectare on the tannin content in the bark of Mimosa caesalpiniifolia. The planting was subdivided into two plots, one thinned at 12 and 55 months of age (T1), while the other plot was kept intact (T2). The dendrometric variables were measured, and ten trees were felled, five in each plot. Subsequently, wood and bark’s volume, mass, and moisture content were determined. Then, the total solids content (TST), the Stiasny index (I), and the condensed tannin content (TTC) were quantified. Dry wood productivity was statistically different between the two treatments, with values of 26.7 and 22.8 t ha-1 for T1 and T2, respectively. The percentage of dry bark corresponded to 16% of the total biomass for both treatments. The only variable that showed a significant difference was I, with values with and without thinning, 59.83 and 79.31%, respectively. Therefore, it was verified that the way the thinning was used changed the I and how they were conducted, favoring the emission of boles and increasing the frequency in the lower diametric classes instead of favoring the increase in DBH. It is concluded that thinning interferes with the biomass volumes and the Stiasny index of M. caesalpiniifolia. However, it does not alter the concentration of tannins present in the species’ bark.

ABSTRACT The study aimed to assess the effect of progressive neutralization on the antimicrobial properties against bacteria and yeasts of wood vinegar obtained from the pyrolysis of Eucalyptus urograndis (clone I144) wood. Wood samples were carbonized at a heating rate of 0.9 °C min-1 until a final temperature of 450 °C, totalizing 8 hours of carbonization. The raw pyrolysis liquids were left to settle, and the aqueous fraction was separated. Then, the aqueous fraction (raw wood vinegar - WV) was purified to yield the WV. WV samples were collected and neutralized from pH 2.5 until 7.5 (2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, and 7.5, by adding NaOH solution. Through the broth microdilution method, the antimicrobial effect of the neutralized samples at each pH was assessed on Pseudomonas aeruginosa (ATCC 27853), Salmonella enteritidis (ATCC 13076), Staphylococcus aureus (ATCC 25923), Streptococcus agalactiae (CEPA CLINICA), and Candida albicans (ATCC 10231). The minimum inhibitory concentration (MIC) and minimum bactericidal (and fungicidal) concentrations were determined through in vitro technics. Results were subjected to logarithmic regression analysis, and statistical models were fitted for each microorganism in the assessed pH range; as pH increased, a progressive decrease in the CIM increased, demanding higher concentrations of WV to inhibit microbial growth. The more resistant strains were S. aureus and S. agalactiae, which required an increase in WV concentration from a minimum of 6.25% at pH 2.5 to reaching 50% at pH 6.0. When at pH 7.0, both strains were not inhibited even at 50% (the highest concentration evaluated in the study). In contrast, C. albicans proved to be the most sensitive strain, starting from 3.12% EP at pH 2.5 and requiring only 25% for inhibition at pH 7.0. The behavior of P. aeruginosa and S. enteritidis followed the pattern of C. albicans, differing only at pH 7.0, where they required 50% of EP. As observed, even at neutral and slightly alkaline pH, the inhibitory activity of EP on microbial growth was maintained to some extent. Nevertheless, even when neutral and slightly alkaline pH values are reached, the inhibitory activity remains at a certain level. Higher pH values of the WV were associated with lower antimicrobial activity. However, its activity remained even at neutral and slightly alkaline pH values.

The indiscriminate use of antimicrobials in animal husbandry can result in various types of environmental contamination. Part of the dose of these products is excreted, still active, in the animals’ feces and urine. These excreta are widely used as organic fertilizers, which results in contamination with antimicrobial molecules. The impacts can occur in several compartments, such as soil, groundwater, and surface watercourses. Also, contamination by antimicrobials fed or administrated to pigs, chickens, and cattle can reach the meat, milk, and other animal products, which calls into question the sustainability of using these products as part of eco-friendly practices. Therefore, a search for alternative natural products is required to replace the conventional antimicrobials currently used in animal husbandry, aiming to mitigate environmental contamination. We thus carried out a review addressing this issue, highlighting wood vinegar (WV), also known as pyroligneous acid, as an alternative antimicrobial with good potential to replace conventional products. In this regard, many studies have demonstrated that WV is a promising product. WV is a nontoxic additive widely employed in the food industry to impart a smoked flavor to foods. Studies have shown that, depending on the WV concentration, good results can be achieved using it as an antimicrobial against pathogenic bacteria and fungi and a valuable growth promoter for poultry and pigs.

ABSTRACT The natural durability of the wood is essential for the definition of its use, and this property can be enhanced with the proper chemical treatment of the wood. Thus, the objective of this study was to evaluate the resistance to termites and decay fungi of Jacaranda copaia wood chemically modified through acetylation. Five experimental treatments were assessed: acetylation for 2, 4, 6 and 8 hours and a control (non-acetylated). The acetylation was carried out by immersing wood samples in acetic anhydride at 90 °C. Acetylated and control samples were subjected to the action of xylophagous termites (Nasutitermes sp.) and decaying fungi (Gloeophyllum trabeum and Trametes versicolor). The acetylation process significantly increased the resistance of Jacaranda copaia wood to the attack of the xylophagous organisms. There was no mass loss after exposure to termites of the wood in any of the acetylation treatments, while in the control wood, mass loss was 9.5%. Regarding the decaying fungi, mass loss occurred in all treatments. Acetylation for 6 and 8 hours were the most efficient chemical treatments, increasing the resistance class of the Jacaranda copaia wood to highly resistant.

Concern about the overexploitation of natural resources has increased in recent decades, especially involving water and its treatment. Paradoxically, one of the sources of water pollution is the treatment itself, due to the use of chemical flocculants, which end up generating sludge that may be highly aggressive to the environment. One of the ways to solve this problem is to use natural flocculants for this purpose, since they are biodegradable and do not harm nature. This study evaluated the efficiency of a natural flocculant produced from tannins extracted from the bark of the cashew tree (Anacardium occidentale) and compared it with two commercial coagulants, Tanfloc® and iron chloride. The water for treatment was collected from a weir. The cashew trees’ bark was collected, ground, and submitted to hot-water extraction to yield the tannins, and the extraction product was cationized. The flocculation tests were carried out using the jar test with solutions having concentrations of 33.3, 66.7, and 100 mg L-1. Turbidity and pH were analyzed before and after flocculation. Among the assessed flocculants, the cationized tannins produced the best responses both for removal of turbidity and final pH of the treated water. Tanfloc® also produced satisfactory results regarding turbidity removal. The iron chloride, besides not properly clarifying the water, left it very acidic. Since the cationized tannins practically did not change the pH and were effective in the removal of turbidity, they represent an interesting, sustainable alternative product to treat the water.

Charcoal is one of the most essential energy sources in the world and is used mainly for domestic and industrial purposes. Brazilian charcoal production occurs in rudimentary masonry kilns without concern for process safety or energy waste. This work aimed to develop a mini carbonization system of three kilns coupled to a vertical smoke burner for optimized and environmentally correct charcoal and wood vinegar (WV) production on small farms. The project was divided into three parts for dimensioning: the three-kiln set, the WV condensing device, and the smoke burner. The condenser was designed following the procedures from the standards of TEMA (Tubular Exchangers Manufacturers Association); ASME (Society of Mechanical Engineers of the United States) Section VIII, Division 1; and the NR-13 (Regulatory Standard) of ABNT (Brazilian Association of Technical Standards). In contrast to the current scenario, in which primitive carbonization technologies are still employed, bringing about low charcoal yields and significant pollution release, the use of a mini-kiln that allows charcoal production and wood vinegar recovery combined with pollutant smoke burning is an interesting eco-friendly solution. Thus, the mini-kiln model presented here brings a low cost and environmental safety to the charcoal production chain, reaching sustainability parameters and offering higher income opportunities to small producers.

ABSTRACT This study aimed to determine the concentration of condensed tannins in the bark of Mimosa tenuiflora (Willd) Poir trees. Additionally, the physical-mechanical properties of cross-laminated timber (CLT) panels bonded with an adhesive based on M. tenuiflora tannins were assessed. Bark was collected from five trees. The adhesive formulation was synthesized by mixing powdered tannins, paraformaldehyde, and water at 50 °C under continuous stirring. Bark tannins extract in its pristine state without any previous chemical treatment or modification was employed to synthesize the adhesive. Viscosity, pH, solids content, and gel time of the adhesive formulation were determined. CLT panels were manufactured with Eucalyptus spp. wood. The bonding performance was assessed by determining the physical (apparent density and water absorption) and mechanical (modulus of elasticity – MOE, modulus of rupture – MOR, and shear strength) properties of the CLT panels. Condensed tannins content in the M. tenuiflora bark was 23.4%. Adhesive properties were pH = 3.93, TS of 50.64%, gel time of 460 s, and 6,000 cP for viscosity. Values of MOE, MOR and shear strength were 4,411, 16.18, and 1.06 MPa, respectively. The M. tenuiflora tannins are promising for the formulation of adhesives to bond CLT.

ABSTRACT Agroforestry systems (AFSs) integrate, through sustainable practices, agricultural and forest crops for the production of wood and food, providing environmental services, and conserving biodiversity. The freijó (Cordia goeldiana) has potential for cultivation in the Amazon for timber purposes, but data on the characteristics of its wood produced in AFSs are scarce. Our objective was to determine the physical-mechanical properties and suggest technological applications of freijó wood produced in a multi-stratified AFS established in the state of Rondônia, Brazil in 1996. Agricultural and forest species were established in the AFS in double rows with 5.0-m x 2.5-m spacing. Three 19-year-old freijó trees were harvested for chemical, physical (density and dimensional stability), and mechanical (compression, static bending, Janka hardness, and shear strength) characterization of the wood. The wood presented a chemical composition similar to tropical hardwoods, was moderately heavy (582.63 kg m-3), and had high dimensional stability in comparison with other consecrated woods on the market (longitudinal, radial, and tangential retraction = 0.25, 4.27, and 6.83%, respectively). The values determined for parallel (32.32 MPa) and perpendicular compression (8.02 MPa), specific strength (55.32 MPa kg-1 m-3), parallel (2373.33 N) and perpendicular Janka hardness (2326.67 N), strength to static bending (63.5 MPa), and shear (5.94 MPa) were similar to the values observed in other high-density tropical woods grown in either monoculture plantations or natural forests. The wood under study is suitable for manufacture of high-value-added products, such as fine furniture, residential floors, musical instruments and structural pieces.

ABSTRACT Condensed tannins are chemical compounds derived from the secondary metabolism of plants. They are of particular interest due to their broad range of technological uses and applications. The objective of this study was to extract, quantify, and characterize by Fourier-transform infrared spectroscopy (FTIR) the bark tannins of four forest species grown in Northeast Brazil: Acacia mangium, Azadirachta indica, Mimosa tenuiflora, and Mimosa caesalpiniifolia. Bark samples were collected from 5 trees of each species grown in a five-year-old forest stand. Samples were collected, grounded, and submitted to extraction with hot water, then measured to determine total solids content (TSC), Stiasny number (SN), and condensed tannins content (CTC). FTIR spectra were acquired from tannin samples fixed in potassium bromide pellets. Among the four species, M. tenuiflora presented the highest CTC, equal to 23.4%, and the purest crude hot-water extract with SN of 91.27%. Based on FTIR characterization, tannins from M. caesalpiniifolia, A. indica, and A. mangium barks were classified as proanthocyanidins and those from M. tenuiflora bark as prodelphinidins.

ABSTRACT This study aimed to assess the influence of the seasonality on the bark tannins content of Acacia mangium trees grown in the Northeastern Brazilian Region and the effect of soil preparation on the results. Two experimental plots of 1.0 ha each were submitted to different soil preparation methods, with two different intensities. The experimental design consisted of four treatments, two types of soil preparation and, two different bark collection seasons (end of the rainy and dry seasons). The bark of the trees was collected in each treatment and the contents of condensed tannins were determined. For each experimental treatment, 15 trees were harvested and debarked. Bark material was submitted to extraction with hot water, obtaining the total solids content (TSC), Stiasny index (I), and the condensed tannins content (CTC). There was no influence of the soil preparation method on the TSC, I, and CTC. However, there was a significant difference in these parameters for tree bark collected in the rainy season, with higher values. The less intensive soil preparation method is recommended due to its lower cost, and bark should be collected at the end of the rainy season for the best yield of condensed tannins.

Pyroligneous extract of Jurema preta (Mimosa tenuiflora [Willd.] Poiret) was evaluated for its efficacy as a cutaneous antiseptic in cats (Felis catus) that were subjected to ovariosalpingohysterectomy. For this purpose, 30 cats without a defined breed were sterilized and divided into two groups. The first group was the positive control, treated with 0.5% chlorhexidine-alcohol solution, and the second group was treated with 20% pyroligneous extract of M. tenuiflora. Regardless of age and sex, all animals had visible healing at similar times. A significant reduction in bacterial growth was observed in animals treated with the extract, and no cytotoxicity was observed in the feline epithelial cells. In addition, surgical wounds of cats treated with M. tenuiflora extract exhibited improved healing. On agar plates, treatment with both chlorhexidine and M. tenuiflora extract resulted in the inhibition zones for all bacterial strains isolated from surgical wounds. Therefore, M. tenuiflora extract is demonstrated to have antiseptic effects on the surgical wounds of cats undergoing ovariosalpingohysterectomy.

ABSTRACT Among the parameters used in the biomass carbonization process, the heating rate is one of the most important. The objective of the present work was to assess the influence of different heating rates on the chemical composition of wood vinegar (WV) from two wood species. Dried disks of Eucalyptus grandis and Mimosa tenuiflora wood were used as raw material. Carbonization runs were carried out in a laboratory muffle furnace at three heating rates (0.7, 1.0 and 1.4 °C/min), with 10 runs at each heating rate, reaching 450 °C. Yields of charcoal, pyrolysis liquids and gases were determined for all carbonization conditions. Crude pyrolysis liquid from each wood species and each heating rate was bi-distilled, yielding purified WV samples. These samples were extracted with ethyl acetate and the organic fraction was analyzed by gas chromatography-mass spectrometry to obtain qualitative and semi-quantitative data. Results showed that lower heating rates produce higher yields of charcoal, while higher heating rates lead to higher yields of pyrolysis liquids and gases. Totals of 57 and 42 chemical compounds were identified in the WV of Eucalyptus and Mimosa, respectively, divided into the following groups: alcohols, ketones, furans and pyrans, and phenolic compounds. In general, higher heating rates led to greater contents of furans and pyrans and lower concentrations of phenolic compounds.

In this study, penetration and retention of the preservative chromated copper borate (CCB) in round pieces of algaroba (Prosopis juliflora (Sw.) DC) were evaluated when subjected to the sap substitution method. Sixteen trunks were randomly selected and divided into four groups. The first group underwent preservative solution 2 hours after felling (called “normal”); the second group underwent preservative solution 24 hours after the cutting down (called “posterior”); the third group was kept immersed in water for 15 days before being subjected to the preservative solution (called “immersed”); the fourth group was not subjected to preservation. After the end of the preservation process, disks were obtained at three different positions of each trunk (base, middle and top) for the evaluation of the parameters of penetration and retention. For analysis of the penetration, colorimetric reactions were used as well as the reviews of the boron and copper elements. Analyses for retaining the elements chromium, copper, and boron were carried out by spectrophotometry. It used a completely randomized factorial design with four replications (round wood) considering two design factors: Situation and Position. The situation factor consisted of three levels (immediate, posterior, immersed), and the position factor (base, middle, top). The effect of the main factors and their interactions, along with the comparison of means, were analyzed considering 5% of probability. The results indicated that pieces that were kept submerged before being submitted to the preservative treatment showed significant improvement in their treatability, maintaining an even distribution of the chemical elements along its length.

The exploitation of wood energy purposes (firewood and charcoal) has caused reduction in native vegetation, added to this, problems are generated for fauna, flora and soil. The objective of the research was to evaluate the energy characteristics of charcoal Aroeira (Myracrodruon urundeuva Allemão) and Leucaena (Leucaena leucocephala (Lam.) R. de Wit). Suppression of five specimens of urundeuva Myracrodruon and Leucaena leucocephala was performed, following quality, phenological and health criteria. Carbonization was performed in duplicate, using anhydrous wood. Also, it was carried out the coal chemical analysis and the determination of true and bulk densities. The gross calorific value was determined by adiabatic calorimeter. The experiment was arranged in a completely randomized design (DIC) and the values were submitted to analysis of variance by the test “F” at 5% of probability level. The Myracrodruon urundeuva wood and Leucaena leucocephala showed no statistical differences, with 41.22% and 40.59% of charcoal. The apparent density of charcoal Myracrodruon urundeuva (0.59 g / cm3) was higher than that of Leucaena leucocephala (0.39 g / cm3), but the species were similar to the true density of charcoal, with 1.21 g / cm3 and 1.11 g / cm3, respectively. Similarly, the gross calorific value of charcoal showed no difference between species the wood, Myracrodruon urundeuva (6869 kcal / kg) and Leucaena leucocephala (6977 kcal / kg). The amount of released volatiles and ash produced was higher on the wood Myracrodruon urundeuva with 33.87% and 3.79%. The fixed carbon content was higher in Leucaena leucocephala (67.15%). The species showed similar energy characteristics so the wood of Leucaena leucocephala can be used for the production and the use of charcoal when compared to the native species which are already known and are used for the same purposes.

The effects of biochar and nitrogen application on yields of upland rice and cowpea and on soil fertility were determined in a greenhouse in Macaíba, RN, Brazil. The trial consisted of the succession of two crops in a completely randomized design and a factorial scheme, with four replicates. Initially, four doses of biochar and four doses of nitrogen were tested for cultivation of rice. Subsequently, four doses of biochar and two doses of nitrogen were tested in half of the pots maintained for planting cowpea. Soil was sampled after rice harvest for half of the pots and at end of the trial for the remaining pots. We evaluated the following parameters: mass of hundred grains of rice, dry shoot mass, panicle number, number of filled spikelets and of empty spikelets, and grain production. Determinations for cowpea were: pod number per pot, grain number per pod, and grain production per pot. Measured soil parameters were: pH, contents of organic carbon, P, K, Ca, Mg, Na, cation exchange capacity, and exchangeable sodium percentage. Biochar addition did not influence yield components of upland rice and cowpea, but resulted in increased soil N retention, which influenced rice dry shoot mass, spikelets sterility, panicle number, and grain mass. Biochar also promoted increased soil pH, potassium content, and exchangeable sodium percentage and decreased calcium and magnesium concentrations.

O milho é cultivado em todo o Brasil para uso na alimentação humana e animal e como matéria prima de biocombustíveis e indústria. Sua produtividade é prejudicada pela degradação de água e solo, da qual a salinização é grave na região semiárida. Três experimentos foram realizados em solos (Argissolo, Cambissolo e Neossolo flúvico) do estado do Rio Grande do Norte para avaliar o efeito do biochar sobre a massa seca e nutrientes de plantas de milho irrigado com águas salinas. Os solos preenchiam colunas de PVC dispostas em casa de vegetação da Universidade Federal Rural do Semiárido, em Mossoró. O delineamento era inteiramente casualisado em esquema fatorial com quatro repetições. Os fatores estudados foram doses de biochar (0; 0,5; 1,0; e 1,5 %) e níveis de salinidade da água de irrigação (0,57; 2,65 e 4,5 dS m-1). O biochar foi obtido da carbonização de Prosopis juliflora (Sw.). Aos 40 dias após emergência determinou-se a massa seca da parte aérea e o teor de N, P, K, Ca e Mg das plantas. Os dados foram submetidos à análise de variância e análise de regressão. As respostas da massa seca e teores de nutrientes do milho indicam que o biochar pode mitigar a salinidade da água de irrigação, dependendo da dose aplicada e do tipo de solo.

The present work has the objective to produce briquettes by using fine charcoal from coconut wastes as raw material and evaluate the briquette quality. Coconut piths were collected at the city of Touros, in Rio Grande do Norte state. After a 2- month air drying, coconut pith was carbonized and hereafter ground in a hammer mill. The resulting charcoal powder was sieved and the fraction less than 40 mesh was used to produce briquettes according to an entirely randomized designed experiment involving 12 treatments and 3 replications. Starch and clay were employed as binders. The treatments were divided into 3 groups, each group corresponding to a proportion of clay, respectively 12, 15 and 18%, based on the total dry weight of the briquette. Within each group, the proportions of starch were 6, 8, 10 and 12%. The carbon powder was mixed with finely ground clay was added and then the pre-gelatinized starch in water at 80°C. The mass for each treatment was mixed until homogeneous, separating quantities of 17grams of mass for each repetition. The briquettes were produced in a laboratory press (pressure of1500psi and pressing time of 4 minutes). The briquettes were dried in an oven at 60°C until constant weight. After drying, the properties of briquettes were evaluated: bulk density, high calorific value, immediate chemical composition (moisture content, fixed carbon, volatile matter and ash) and compressive strength. Best treatments for trading products were 12/12 e 12/15.

‘Caatinga’ is an exclusive Brazilian biome, which features a wide variety of fauna and flora, and a good part of these are endemic varieties. Over the years, the abolition of ‘Caatinga’ by human activities has greatly reduced this biome. This fact is mainly due to the use of the energy potential of plant species without proper concern about the sustainability of it. A better understanding of the energy potential of plant species of ‘Caatinga’ enables a more appropriate management. The objective of this study was to evaluate the potential energy and the physical and chemical characteristics of wood species Amburana cearensis (Germans) A. C. Smith and Piptadenia stipulacea (Benth.) Ducke. Five trees of each species were felled, randomly sampled in ‘São Bento’ site, located in the city of Patos, Paraíba state. The trees were identified and transported to the Department of Forest Product Technology, Federal University of Campina Grande. From each tree, small discs were removed (5 cm thick) to 0 (base), 25, 50, 75 and 100% of the commercial height of the trunk (up to 5 cm in diameter) and large disks (15 cm thick) before and after each small disk, the small discs were divided into four parts, wedge-shaped, passing through the medulla. Two opposing wedges were used to determine the density and the rest was reserved for the physical and chemical wood analyses and the wood discs were destined for greater achievements of carbonizations. Basic density was determined according to the method of hydrostatic balance and to determine the basic density of each tree used as a weighting factor the volume between sections of each disk. After air drying, the samples for chemical analysis were transformed into sawdust and made quantitative determinations of total extractives, lignin, ash and holocellulose content was estimated by difference from the initial mass [100% - (content total extractives + lignin + ash)]. Samples intended for carbonizations were transformed into chips, and charred in an electric furnace (furnace) for 5 hours and 30 minutes. The income from the carbonization products as well as the physical and chemical properties of charcoal were determined. Averages significantly higher than 1% probability of lignin, holocellulose content, total extractives and ash wood were found for the species Amburana cearensis and Piptadenia stipulacea, and this latter had higher average lignin content and holocellulose content. The gravimetric yield was similar for both species, while the condensed liquid yield was significantly higher for Amburana cearensis. In relation to coal quality, higher values were observed for gross calorific value and fixed carbon for Piptadenia stipulacea, while Amburana cearensis exhibited higher levels of volatiles and ash.

ABSTRACT This study aimed to estimate the biomass and energy of a clonal planting short rotation experiment with hybrids of Eucalyptus urophylla ST Blake x Eucalyptus grandis (Hill) Maiden, deployed in 3 m x 3 m spacing, at the Academic Unit Specialized in Agricultural Sciences, Macaíba/RN. The analysis were performed at the Laboratory Panels and Wood Energy, Federal University of Viçosa, in which the following ratings on wood three cultivars (GG100 ; AEC0144 and AEC0224) were performed: determination of basic density, high calorific power, chemical analysis, thermogravimetric analysis and subsequent calculations for estimating the mass production and energy were performed. The base (10 cm from the ground), the third and two thirds of commercial tree height: composed for analysis, taken from three points along the stem samples were used. The design of the experiment was a completely randomized. Data were subjected to analysis of variance and the means were compared by Tukey test (a= 0.05). The clone who excelled in the first year of planting was the GG100 with 11,805 kW.h.ha-1 of energy productivity, followed by clone AEC0224 (6,755 kW.h.ha-1) and AEC0144 (4,405 kW.h.ha-1). The performance of this clone was due to mainly the higher volumetric growth. The wood quality among clones showed little difference. It should stimulate the deployments of species of short rotation in the state of RN to supply the elevated energy demand of forest biomass in the region.

Este trabalho teve como objetivo avaliar o perfil de decomposição térmica da madeira de oito espécies utilizando as técnicas de termogravimetria (TGA) e calorimetria diferencial exploratória (DSC), bem como a consistência desses métodos para decidir quais espécies devem ser indicadas para produção de energia e carvão vegetal, comparando-os com os rendimentos gravimétricos da carbonização obtidos a partir de carbonizações em mufla de laboratório. Para as análises por TGA e DSC, amostras de serragem foram aquecidas à taxa de 10 °C min-1, sob atmosfera de nitrogênio, em vazão de 50 ml min-1 até a temperatura final de 600 °C. Foram determinados os valores de densidade básica e poder calorífico superior da madeira. As carbonizações foram realizadas em mufla de laboratório à taxa de 50 °C h-1 até a temperatura máxima de 450 °C, obtendo-se os rendimentos em carvão vegetal. Também foram determinados os valores de densidade aparente do carvão das oito espécies após a carbonização. Os resultados das análises térmicas indicaram perfis de decomposição pirolítica das madeiras e evidenciaram aquelas mais estáveis à ação térmica. O comportamento da estabilidade térmica das madeiras das oito espécies foi confirmado pela análise dos rendimentos da carbonização em mufla, em comparação com a análise por TGA e DSC. As madeiras de Aspidosperma pyrifolium e Mimosa tenuiflora apresentaram maior estabilidade térmica e, portanto, maiores rendimentos em carvão vegetal, bem como maiores densidades aparentes. As técnicas de termogravimetria e calorimetria diferencial exploratória são satisfatórias para avaliação da decomposição térmica das madeiras e garantem consistência na escolha de madeiras que resultam em maior rendimento e maior qualidade do carvão vegetal.

http://dx.doi.org/10.5902/198050989293The objective was to evaluate the energy potential of woods of species under forest management plan from Seridó region in the Rio Grande do Norte state. It was used the wood species Jurema Preta, Pereiro, Marmeleiro, Catingueira, Mororó, Imburana, Jurema Branca and Mofumbo, at 20 years old, originated from the Dominga´s farm in the Caicó/RN municipality. The density, the content of volatiles, the ash and fixed carbon, calorific value, elemental composition and carbon/nitrogen (C/N) and carbon/hydrogen (C/H) analysis were carried out in the wood. Additionally, the amount of energy produced in kW.h.m-3 and kW.h.ha-1 for all species was estimated. The experiment was conducted in a completely randomized design with eight treatments (species), four replicates (sample trees), adding up to 32 sampling units. There were significant differences, at 5% significance between treatments for all variables, except for hydrogen percentage and C/H ratio. It was concluded that Mororó´s wood shows high energy potential, and along with Jurema Preta, presents higher energy generation per m3, and provides greater economy for the same productivity. The energy potential Jurema Preta wood´s stands out among the species. Pereiro´s wood stands for energy production per hectare. Marmeleiro and Jurema Branca´s woods are indicated as direct burning potential and Imburana´s wood is not recommended for power generation.

The objective was to evaluate the energy potential of woods of species under forest management plan from Seridó region in the Rio Grande do Norte state. It was used the wood species Jurema Preta, Pereiro, Marmeleiro, Catingueira, Mororó, Imburana, Jurema Branca and Mofumbo, at 20 years old, originated from the Dominga´s farm in the Caicó/RN municipality. The density, the content of volatiles, the ash and fixed carbon, calorific value, elemental composition and carbon/nitrogen (C/N) and carbon/hydrogen (C/H) analysis were carried out in the wood. Additionally, the amount of energy produced in kW.h.m-3 and kW.h.ha-1 for all species was estimated. The experiment was conducted in a completely randomized design with eight treatments (species), four replicates (sample trees), adding up to 32 sampling units. There were significant differences, at 5 % significance between treatments for all variables, except for hydrogen percentage and C/H ratio. It was concluded that Mororó´s wood shows high energy potential, and along with Jurema Preta, presents higher energy generation per m^3, and provides greater economy for the same productivity. The energy potential Jurema Preta wood´s stands out among the species. Pereiro´s wood stands for energy production per hectare. Marmeleiro and Jurema Branca´s woods are indicated as direct burning potential and Imburana´s wood is not recommended for power generation.

O objetivo deste estudo foi quantificar os estoques em volume, biomassa e carbono na madeira de um fragmento de Caatinga Arbustiva-Arbórea, na região Nordeste do Brasil, no Município de Caicó, RN. Realizou-se o inventário e a amostragem do material biológico para análises de biomassa e carbono. Para a conversão de volume de madeira em biomassa foi obtida a densidade básica da madeira de oito espécies que representavam 91% do valor de importância (VI) do fragmento. A porcentagem de carbono dessas espécies foi determinada por análise elementar da madeira. O estoque de carbono foi determinado considerando-se a porcentagem de carbono multiplicada pela biomassa de cada árvore. Para as espécies que não foram analisadas (9% do VI) utilizou-se um valor de densidade básica média () e da média de carbono (), ponderados pelo valor de importância das espécies amostradas. Foi observado um estoque volumétrico de madeira igual a 15,5 m³ ha-1. A biomassa determinada foi de 12 t ha-1, que correspondeu a um estoque de carbono de 5,7 t ha-1.

http://dx.doi.org/10.5902/198050986624A vegetação nativa da Região Nordeste vem sendo explorada e utilizada de forma intensiva e de maneira inadequada para finalidades energéticas e nas construções rurais, tornando-se evidente a importância dos conhecimentos relativos às características da madeira. Assim, essa pesquisa teve como objetivo avaliar as características físico-químicas e energéticas da madeira, os rendimentos da carbonização e a caracterização do carvão vegetal das espécies Poincianella pyramidalis Tul. L. P. Queiroz (Catingueira) e Handroanthus impertiginosus (Mart. ex DC.) Mattos (Pau-d’arco). Para atender ao objetivo, foram abatidas cinco árvores de cada espécie, amostradas aleatoriamente na Fazenda Santa Bárbara, localizada no município de São Mamede-PB. As árvores foram devidamente identificadas e transportadas para o Setor de Tecnologia de Produtos Florestais (STPF) da Universidade Federal de Campina Grande. De cada árvore, foram retirados toretes de 30 cm de altura a 0 (base), 25, 50, 75 e 100 % da altura comercial do tronco, considerada até 5 cm de diâmetro. Da porção mediana de cada torete, foi retirado um disco de 2,5 cm de espessura, subdividido em quatro partes, em forma de cunha, passando pela medula. Duas cunhas opostas foram utilizadas para a determinação da densidade básica, e as restantes foram reservadas para a realização das análises físicas, químicas e energéticas da madeira, os rendimentos em carbonização e a caracterização do carvão produzido pelas espécies estudadas. A densidade básica foi determinada de acordo com o método da balança hidrostática e para a determinação da densidade básica média de cada árvore utilizou-se como fator de ponderação o volume entre seções de cada disco. Após a secagem ao ar, as amostras destinadas às análises químicas foram transformadas em serragem e feitas determinações quantitativas de extrativos totais, da lignina, das cinzas, e o teor de holocelulose foi estimado por diferença. As amostras destinadas à carbonização foram transformadas em cavacos, e carbonizadas em forno elétrico (mufla) por cinco horas e meia. Foram feitas determinações dos rendimentos dos produtos das carbonizações, e das propriedades físicas e químicas do carvão vegetal. De modo geral, as madeiras estudadas apresentaram características físicas semelhantes. Com relação às características químicas, o pau-d’arco apresentou maior teor de lignina (28,40 %), e não houve diferença significativa entre as espécies para o teor de holocelulose. O poder calorífico superior da catingueira exibiu os menores valores, para a madeira (4.413,50 kcal.kg-1) e carvão vegetal (6.247,80 kcal.kg-1), respectivamente. A catingueira apresentou um maior rendimento em carvão (43,03 %), mas de qualidade inferior. O carvão vegetal do pau-d’arco apresentou o maior teor de carbono fixo (67,68 %). As espécies apresentaram densidade verdadeira do carvão e rendimento em carbono fixo semelhantes. Pode-se concluir que as duas espécies de ocorrência no semiárido Nordestino, apresentam boas características para produção de carvão. De modo geral, o pau-d’arco apresentou as melhores propriedades para fins energéticos.

Este estudo objetivou avaliar o desempenho de fornos retangulares no processo de carbonização, envolvendo duas rotinas de carbonização. As rotinas analisaram a influência de tatus e câmaras de combustão externa no processo de carbonização em quatro fornos retangulares instrumentados com termopares para acompanhamento da temperatura, bem como o balanço de massa e energia do sistema. A lenha utilizada na carbonização foi o clone A08, híbrido do cruzamento entre Eucalyptus grandis e Eucalyptus urophylla, com idade de 7 anos e comprimento da lenha de 3 m. Foram realizadas oito carbonizações em cada rotina. De acordo com os resultados, verificou-se que a rotina 2, caracterizada pelo uso das câmaras de combustão externa, foi mais eficiente no controle da carbonização; a instrumentação do forno é uma técnica viável, mas que requer ajustes para caracterizar, com precisão, o fenômeno da carbonização. No balanço de massa e energia, verificou-se que as perdas foram maiores que os ganhos em produção, para lenha com elevados teores de umidade.

The Caatinga is one of the richest Brazilian biomes, however its biodiversity is constantly threatened by human activities, especially the use of fire for cleaning and/or increase areas for agricultural activities. In this study, it's determined the months and the days with highest risk of forest fires in the Seridó Ecological Station in Serra Negra do Norte-RN and was developed with daily data of precipitation and relative humidity of the years 1999-2004, collected in the Climatological Station, through Monte Alegre Formula. The results show that in January, February, March, April and May, the rainy season in the region, are the months with the lowest fire danger, are classified as null to very high risk, while August, September, October, November and December, dry season in the region, reached the highest degree of danger, being classified as high to very high risk. During the study period almost 75% of days had high to very high fire hazard while the levels null and small together reached more than 13%, more occurring in the months January to April.

O objetivo deste trabalho foi avaliar o efeito da acetilação das partículas de madeira de Eucalyptus grandis e da inclusão de partículas de polietileno de baixa densidade (PEBD) e de alta densidade (PEAD) e de embalagens cartonadas nas propriedades de chapas de aglomerado. As partículas de madeira foram produzidas em laboratório a partir de toras que foram desdobradas em tábuas, convertidas em baguetas, depois em flocos e, finalmente, transformadas em partículas. Embalagens cartonadas e de polietino de alta e baixa densidades foram coletadas em depósitos de material reciclável e processadas em moinho de martelo. A acetilação foi realizada em autoclave com controle de pressão e temperatura. A acetilação promoveu significativa estabilização dimensional dos painéis, entretanto diminuiu algumas propriedades mecânicas. A adição de polietileno reduziu as propriedades mecânicas, em especial a flexão estática (MOR e MOE), porém, de modo geral, melhorou a estabilidade dimensional dos painéis, independentemente do tipo de partícula. No entanto, a adição de embalagens cartonadas reduziu a resistência mecânica e promoveu maior adsorção de vapor de água, inchamento em espessura e expansão linear, tanto nas chapas contendo partículas acetiladas quanto naquelas que não as continham.The objective of this study was to evaluate the effect of eucalyptus grandis particles acetylation and the addition of polyethylene of low (pebd) and high density (pead) and paperboard particles in the properties particleboard. Wood particles were produced in laboratory from logs that were split into plaks, baguettes and then converted into flakes and finally transformed into particles. Paperboard and polyethylene collected in recyclable material stores and processed in a hammer mil. Acetylation was performed in autoclave with pressure and temperature control. Wood particles acetylation promoted a significant stabilization of the particleboards but decrease some mechanical properties. The addition of paperboard reduced all the mechanical properties and promoted a greater adsorption of water vapor, thickness swelling and linear expansion, for boards containing acetylated or non acetylated wood particles. The addition of polyethylene reduced the mechanical properties, specially the static bending (mor and moe), however resulted in more stable boards.

Este estudo teve como objetivo principal avaliar a carga de trabalho físico e a análise biomecânica de 20 trabalhadores da carbonização em fornos tipo "rabo-quente", localizados no Norte do Estado de Minas Gerais. Para análise da freqüência cardíaca, foi utilizado o sistema Polar Eletro Oy da Finlândia. O tempo consumido pelos trabalhadores por atividade foi avaliado através do método de cronometagem individual e a análise biomecânica, realizada por programa computacional desenvolvido pela Universidade de Michigan. Os resultados evidenciaram que a carga cardiovascular exigida para a realização da atividade era de 44,5% e classificada como moderadamente pesada. A operação que mais consumia tempo de trabalho era a vedação. Havia risco de compressão no disco vertebral L5 - S1 na operação de carga, durante as fases de levantamento da rede e remoção de tora.The main objective of this study was to evaluate the physical work load and the biomechanical analysis of 20 workers at the wood carbonization in hot tail charcoal kilns, located in the North of the Minas Gerais State, Brazil. Cardiac frequency was analyzed using the Polar Eletro Oy system from Finland. The time required by the workers per activity was evaluated through the individual chronometry method and the biomechanical analysis was carried out by a software developed by the Michigan University. The results showed that the cardiovascular load required was of 44.5%, which was classified to be moderately heavy. The most time consuming activity was the sealing of the kiln. There is a compression risk of the L5 - S1 vertebral disk for the kiln loading labor, during the steps basket lifting and log removal.

Este trabalho teve como objetivo determinar as propriedades de chapas de madeira aglomerada confeccionadas com partículas geradas de maravalhas e flocos de Eucalyptus grandis, E. urophylla e E. cloeziana. Quando necessário, para manter a massa específica das chapas em 0,70 g/cm³ foram adicionadas partículas de Pinus elliottii. Os eucaliptos foram obtidos nos Municípios de Ponte Alta (Região do Vale do Rio Doce) e Três Marias (Região de Cerrado), em Minas Gerais. As densidades básicas das espécies procedentes do Município de Ponte Alta foram iguais a 0,55; 0,61; e 0,70 g/cm³, enquanto aquelas procedentes do Município de Três Marias foram iguais a 0,56; 0,58; e 0,69 g/cm³, respectivamente. A densidade do Pinus elliottii, cultivado no Município de Viçosa, foi de 0,45 g/cm³. As partículas para a confecção das chapas foram obtidas pelo processamento de flocos (0,48 x 20 x 90 mm) e maravalhas, em moinho de martelo, e selecionadas com peneiras manuais. Os coeficientes de esbeltez dessas partículas foram iguais a 19,87 e 4,66, respectivamente. Utilizou-se adesivo de uréia-formaldeído na proporção de 8% em relação à massa seca de madeira. As chapas confeccionadas com partículas processadas de flocos e contendo maior quantidade de madeira de eucalipto apresentaram maior adsorção de água, inchamento e expansão linear. Os maiores valores de dureza Janka e compressão paralela foram observados nas chapas confeccionadas com partículas processadas de maravalhas. Os valores médios de tração perpendicular, módulo de ruptura e módulo de elasticidade foram maiores nas chapas confeccionadas com partículas de flocos processados. As chapas confeccionadas com madeiras da Região de Três Marias apresentaram maiores resistências à compressão paralela, tração perpendicular e módulo de ruptura.This work aimed to evaluate properties of particleboards manufactured with particles derived from planner shavings and flakes of Eucalyptus grandis, E. urophylla and E. cloeziana. Pinus elliottii particles were mixed with eucalyptus particles when necessary and in an amount enough to keep boards densities at 0.70 gr/cm³. Eucalyptus wood was obtained from the municipalities of Ponte Alta (Vale do Rio Doce) and Três Marias (Cerrado Region), both in Minas Gerais state, Brazil. Eucalyptus grandis, E. urophylla and E. cloeziana densities collected in Ponte Alta were 0.55; 0.61 and 0.70 g/cm³ whereas those collected from Três Marias were 0.58; 0.58 and 0.69 g/cm³, respectively. The density of Pinus elliottii cultivated in the region of Viçosa was 0.45 g/cm3. Particles were produced by processing flakes (0.48 x 20 x 90 mm) and planner shavings in hammer mill. Mean slenderness ratios were 19.87 and 4.66 for particles produced from flakes and shavings, respectively. Urea-formaldehyde adhesive was applied in the proportion of 8% of particle dry mass. Boards manufactured with higher amount of eucalyptus particles absorbed more water and had higher swelling and linear expansion. Highest hardness and parallel compression were observed on boards manufactured with particles from shavings, whereas highest internal bond, modulus of rupture and elasticity values were found for boards fabricated with particles from flakes. Boards made with particles from wood derived from Três Marias had higher means for parallel compression, internal bond and modulus of rupture.

Este trabalho teve como objetivo principal a análise econômica e financeira de um projeto com 100 fornos tipo container industrial e 100 fornos tipo retangular de 40st. para a produção de carvão vegetal. Para tanto, utilizaram-se como indicadores financeiros a lucratividade, rentabilidade, prazo de retorno do investimento e ponto de equilíbrio. Os indicadores econômicos utilizados para proceder a análise econômica foram o VPL, TIR, B(C)PE e B/C. Concluíram que os fornos são viáveis do ponto de vista econômico e financeiro. Entretanto o forno container por ter maior VPL daria um retorno mais lucrativo quando comparado ao retangular de 40 st.This work aimed at the economic and financial analysis of a project with 100 units of both industrial container and 40-st rectangular kilns for charcoal production. The following financial indicators were used in the analysis: profitability, yield, payback period and break-even point. The economic indicators used in the economic analysis were VPL, TIR, B(C)PE and B/C. In this study, the two kilns are economic and financially viable. However, the container was more lucrative than the 40-st rectangular kiln.

Esta pesquisa foi desenvolvida no ambiente de trabalho da produção de carvão vegetal em bateria de fornos de superfície do tipo "rabo-quent"e, localizado na latitude de 17·27' oeste e longitude de 45º11' sul no Estado de Minas Gerais, nos meses de março a junho de 2003. O objetivo geral foi avaliar o perfil de trabalhadores e as condições ergonômicas na atividade de produção de carvão vegetal em bateria de fornos de superfície do tipo "rabo-quente". Os objetivos específicos foram: a) avaliar as características pessoais, sociais, econômicas e profissionais do operador; b) estudar o clima do local de trabalho (temperatura); e c) analisar a capacidade aeróbica do trabalhador. A metodologia empregada foi a proposta por Couto (1996) Apud (1987) e Sant'anna (1998). Pela análise dos dados, pôde-se concluir que o indivíduo da amostra era jovem, mestiço, casado, com poucos filhos e poucos dependentes financeiros, baixo nível de escolaridade, estatura média de 171,40 cm e média de peso corporal de 68,40 kg, 20% de analfabetos, de origem predominantemente rural e que professava a religião Católica. O valor do Indice de Bulbo Úmido Termômetro de Globo (IBUTG) encontrado no ambiente de produção de carvão vegetal estava de acordo com a NR 15. A capacidade aeróbica em mililitros de oxigênio por quilograma por minuto apresentou valor médio igual a 35,17 (ml02/kg/min); o menor valor foi igual a 30,56 (ml 02/kg/min) e o maior, igual a 39,23 (ml02/kg/min).This investigation was developed in the work environment of charcoal production in a line of surface kilns located at 17º 27' w latitude and 45º 11' 5 longitude in the state of Minas Gerais from March to June 2003. The general objective of this work was to evaluate the worker profile and ergonomic conditions of the charcoal production activity in a line of surface kilns. The specific objectives of this work were: a) to evaluate the individual, social, economic and professional characteristics of the operator; b) to evaluate the type of weather at the work place (temperature); c) the evaluate the aerobic capacity of the worker. The methodology used was proposed by Couto (1996) apud (1987) and Sant'Ana (1998). Data analysis showed that the sampled individual is young, African descendant, married with few children and few financial dependants, low level of education, average height of 171.40 cm and average body weight of 68.40 Kg, 20% of illiteracy, mainly rural origin and catholic religion. The Wet Bulb Globe Thermometer Index (IBUTG) found in the charcoal production environment complied with the NR 15 regulation. The aerobic capacity in milliliters of oxygen per kilogram per minute showed an average value of 35.17 ml O2 / Kg /min, and the highest value was equal to 39.25 ml O2 / Kg /min.

Este trabalho teve como objetivo avaliar as propriedades de chapas de 0riented Strand Board (OSB), fabricadas com flocos de madeira de Eucalyptus grandis, Eucalyptus urophylla e Eucalyptus cloeziana e oriundas dos Municípios de Ponte Alta e Três Marias, no Estado de Minas Gerais. As massas específicas básicas das três espécies de eucaliptos das duas regiões foram, respectivamente: Ponte Alta (0,55; 0,61; e 0,70 g/cm³) e Três Márias (0,56; 0,58; e 0,69 g/cm³). Quando necessário, para manter as massas específicas das chapas próximas de 0,70 g/cm³ foram acrescentadas às partículas de madeira de eucalipto partículas de madeira de Pinus elliottii, oriundo da cidade de Viçosa, com massa específica de 0,45 g/cm³. Os flocos foram gerados nas dimensões médias de 90,00 x 20,00 x 0,46 mm. O adesivo utilizado foi o fenol-formaldeído, na proporção de 8% de sólidos, em relação à massa seca de partículas. Parte dos flocos de eucaliptos foram acetilados. As chapas foram prensadas à temperatura de 170 °C e 32 kgf/cm² de pressão. As propriedades das chapas foram determinadas segundo as normas da ABNT NBR 14810-3 (2002) e ASTM-D 1037 (1991). Os resultados foram comparados utilizando-se as normas ANSI/A - 208.1 (1993) e CSA 0437-93 (1993). As chapas contendo partículas acetiladas foram mais estáveis e adsorveram menos umidade. Na tração perpendicular, observou-se que as chapas contendo 100% de flocos acetilados apresentaram resultados inferiores ao estipulado pela norma CSA O437-0/93 (1993). A resistência ao arrancamento de parafuso, módulo de ruptura (paralelo e perpendicular) e compressão longitudinal (perpendicular), foi reduzida pela acetilação nas chapas contendo 100% dos flocos acetilados. As espécies que apresentaram, numericamente, as maiores médias para resistência mecânica foram: Eucalyptus grandis não acetilado (dureza Janka) e Eucalyptus cloeziana misturado com Pinus sp (módulo de ruptura). Somente a resistência à compressão longitudinal foi afetada pela região de origem da madeira. Os painéis fabricados com madeira de Eucalyptus urophylla, oriunda do Município de Três Marias, tiveram médias inferiores aos das chapas feitas com a mesma espécie, porém oriundas do Município do Rio Doce.The objectives of this work was to evaluate the properties of OSB (Oriented Strand Board). Wood was collected from Eucalyptus grandis, Eucalyptus urophylla and Eucalyptus cloeziana on the municipalities of Ponte Alta and Três Marias, in the state of Minas Gerais. Wood densities were respectively: Ponte Alta (0.55, 0.61 and 0.70g/cm³) and Três Marias (0.56, 0.58 e 0.69g/cm³). Strands of Pinus elliottii, derived from the city of Viçosa, with density of 0.45g/cm³, were added to strands of eucalyptus when necessary to keep board densities close to 0.70g/cm³. Flakes were fabricated in a laboratory disk flaker measuring approximately 20.00 x 0.46 x 90.00 mm. Phenol-formaldehyde adhesive was applied at 8% solid rate, in relation to particle dry mass. Part of the treatment was carried out with flakes from acetylated eucalyptus. The boards were pressed at 170°C and 32 kgf/cm² pressure. Boards properties were determined according to the ABNT NBR 14810-3 (2002) and ASTM-D 1037 (1991) norms. The results were compared using the ANSI/A - 208.1 (1993) and CSA 0437-93 (1993) norms. OSB manufactured with any amount of acetylated flakes was more stable and absorbed less water. However the resistance to perpendicular traction of OSB with 100% of acetylated flakes was inferior to the stipulated by the CSA O437-0/93 (1993) norm. It was also found that acetylation had a negative effect on screw withdrawal resistance, module of rupture (parallel and perpendicular) and longitudinal compression resistance (perpendicular) of Eucalyptus grandis OSB having 100% of their flakes acetylated. Boards that presented numerically the highest means were manufactured with non-acetylated flakes of Eucalyptus grandis (Janka hardness) and Eucalyptus cloeziana mixed with Pinus sp (module of rupture). Only resistance to longitudinal compression was affected by the wood origin. OSB manufactured with Eucalyptus urophylla wood, from the Cerrado, had lower means than OSB made of the same species, however, from Vale do Rio Doce.

Este trabalho teve como objetivo determinar as propriedades de painéis fabricados com mistura de partículas de madeira de Eucalyptus grandis, polietileno de alta densidade, polietileno de baixa densidade e polipropileno. Empregaram-se duas formulações adesivas (uréia-formaldeído e uréia-formaldeído contendo 0,5% de epóxi). De modo geral, as propriedades dos painéis foram afetadas pela composição das partículas. Os painéis com melhores propriedades foram fabricados com 75% de partículas de madeira e 25% de partículas de polietileno de alta densidade. A adição de epóxi ao adesivo uréico aumentou os valores do módulo de ruptura, dureza Janka, e reduziu o inchamento, em espessura, de alguns painéis. As propriedades mecânicas da maioria dos painéis, exceto o módulo de elasticidade, ultrapassaram os valores mínimos estabelecidos na norma ANSI/A1-208/93.The objective of this work was to establish the properties of particleboards fabricated with blends of Eucalyptus grandis, low-density polyethylene, high-density polyethylene and polypropylene particles. Two adhesives formulations were used (urea-formaldehyde and urea-formaldehyde plus 0,5% of epoxy adhesive). Panel properties were affected by particle composition. Panels with best properties were fabricated with 75% of wood particles and 25% of high density polypropylene. The addition of epoxy to the urea-formaldehyde adhesive improved of the values of modulus of rupture, hardness and reduced the amount of thickness swelling. Except for the modulus of elasticity, board properties meet grade M-2 ANSI/A1-208/93 requirements.

Este trabalho objetivou determinar algumas características anatômicas e dimensões de fibras, elementos dos vasos, células do parênquima e dos raios da madeira da Mimosa tenuiflora (Willd.) Poir. Determinaram-se, ainda, a fração parede das fibras e o porcentual das fibras, dos vasos, dos raios e das células parenquimatosas, bem como a densidade, rendimento e propriedades do carvão vegetal. Conclui-se que a madeira de Mimosa tenuiflora possui poros predominantemente solitários, geminados e múltiplos em agrupamento radial; poros distribuídos em porosidade difusa uniforme; parênquima axial paratraqueal vasicêntrico, vasicêntrico confluente, aliforme e aliforme confluente; raios multisseriados, bisseriados e, menos freqüentemente, unisseriados; e fibras de parede espessa e muito curtas. Obteve-se um rendimento de 39,68% em carvão vegetal, com teor de carbono fixo de 71,70%, densidade igual a 0,51g/cm³, carbono fixo de 71,79 e poder calórico de 6.866 cal/g.The objective of this work was to determine anatomical characteristics, and dimensions of fibers, vessels and parenchyma and ray cells of Mimosa tenuiflora (Willd.) Poir wood. Fibers wall fraction, the percentage of fibers, vessels and ray and parenchyma cells, as well as density and charcoal production and properties were determined. The wood of Mimosa teniflora presents predominantly solitary, geminated and multiple porous in radial groups; porous distributed in uniform diffuse porosity; axial parenchyma paratracheal vasicentric, confluent vasicentric, aliform and confluent aliform; multiseriate, biseiat rays and, less frequently, uniseriate ones; very short fibers with thick walls. Charcoal yield was 39.68% with a 0.51g/cm³ density, 71.79% carbon content and 6886cal/g calorific value.

Os taninos foram extraídos da casca de Eucalyptus grandis e Eucalyptus pellita, com água quente, à qual se adicionaram 4,5% de sulfito de sódio, durante três horas. As temperaturas da solução foram iguais a 70 e 100 ºC para Eucalyptus grandis e Eucalyptus pellita, respectivamente. Para a produção dos adesivos e com o intuito de reduzir a sua viscosidade, os taninos foram sulfitados com sulfito de sódio e ácido acético. Formulações adesivas foram preparadas adicionando-se 0, 25, 50, 75 ou 100% de adesivos tânicos ao adesivo comercial de uréia-formaldeído. Foram fabricadas chapas de flocos de Pinus elliottii Engelm. e Eucalyptus grandis, utilizando-se 8% da formulação adesiva. As propriedades das chapas foram determinadas segundo a norma ASTM D-1037, de 1993. Observou-se que as propriedades das chapas foram superiores ao mínimo estabelecido pela norma ANSI/A 280.1-93, exceto no caso da resistência à umidade. Verificou-se, ainda, que o emprego de uma formulação adesiva contendo resina à base de uréia-formaldeído e tanino-formaldeído pode melhorar algumas propriedades.Bark tannins of Eucalyptus grandis and Eucalyptus pellita were extracted with 4,5% sodium sulfite in hot water solution for a period of three hours. Solution temperatures were 70 and 100ºC, for Eucalyptus grandis and Eucalyptus pellita bark respectively. Tannins were reacted with acetic acid and sodium sulfite to reduce adhesive viscosity. Adhesive formulations were prepared adding 0, 25, 50, 75 or 100% of tannin adhesives to the commercial urea-formaldehyde adhesive. Flakeboards were fabricated with 8% resin content. Board properties were determined according to ASTM D-1037 standards. Except for humidity, all board properties were superior to the values established by ANSI.A 208.1-93 commercial standard. Addition of tannins to the urea-formaldehyde adhesive improved some properties.

Os taninos foram extraídos das cascas de Eucalyptus grandisW. Hill ex Maiden e Eucalyptus pellita F. Muell. com água quente e a adição de 4,5% de sulfito de sódio, durante três horas, nas temperaturas de 70 e 100 ºC, respectivamente. Para a produção dos adesivos, os taninos reagiram com ácido acético e sulfito de sódio, para a redução da viscosidade. Técnicas de DSC (calorimetria diferencial exploratória) foram utilizadas para determinar os parâmetros cinéticos dos adesivos. Foram produzidas, em laboratório, chapas de flocos de Eucalyptus grandis e Pinus elliottii, utilizando-se 8 e 10% de adesivo de tanino sulfitado e 8% de adesivo comercial de uréia-formaldeído. As propriedades das chapas foram determinadas segundo a norma ASTM D-1037 de 1993. As propriedades das chapas fabricadas apenas com adesivo à base de taninos foram superiores ao mínimo exigido pela norma comercial ANSI/A 208.1-93, com exceção daquelas relacionadas com umidade. As chapas produzidas com adesivos de taninos da casca de Eucalyptus grandis foram superiores àquelas fabricadas com adesivos de taninos da casca de Eucalyptus pellita.Eucalyptus grandis and Eucalyptus pellita bark tannins were extracted with hot water, with addition of 4,5% of sodium sulfite, for a three hours period, at temperatures of 70ºC and 100ºC, respectively. The tannins were reacted with acetic acid and sodium sulfite, for reduction of adhesive viscosity. Calorimetric exploratory differential techniques were used to determine adhesive kinetic parameters. Flakeboards were fabricated with Pinus elliottii wood flakes, using 8% or 10% of Eucalyptus grandis or Eucalyptus pellita tannin-based adhesives or 8 % of commercial urea-formaldehyde adhesive. Board properties were determined according to ASTM D-1037 standard. Except for moisture related properties, the boards fabricated only with tannin-based adhesive were superior to the minimally acceptable ANSI/A 208.1-93 standard. The flakeboards fabricated with Eucalyptus grandis bark tannins were better than those fabricated with Eucalyptus pellita bark tannins.

O objetivo deste trabalho foi avaliar as propriedades de painéis fabricados com partículas de madeira, poliestireno (PS) e polietileno tereftalato (PET). Foram utilizadas três proporções, em relação à massa seca de madeira, de poliestireno (0, 25 e 50%) e duas proporções de PET/PS (5/20 e 10/40%), combinadas com 50, 75 ou 100% de partículas de madeira de Pinus elliottii. Os painéis foram produzidos com adesivos à base de uréia-formaldeído ou de fenol-formaldeído, em três teores (0, 4 ou 6%) e três níveis de solução de poliestireno em tolueno (0 , 4 e 6%), todos calculados em relação à massa seca total dos painéis. Foram produzidos painéis de aproximadamente 400 x 400 x 10 mm, em camada única, com densidade aproximada de 0,6 g/cm³. Determinou-se a resistência dos painéis à tração perpendicular à superfície, à flexão estática (módulos de ruptura (MOR) e elasticidade (MOE)), ao arrancamento de parafusos, bem como a absorção de água e o inchamento em espessura, após 24 horas de imersão. Todas as propriedades mecânicas dos painéis foram superiores às exigidas pela norma ANSI/A 208.1-1993. Contudo, todos os painéis absorveram água em valores superiores àqueles normalmente observados em painéis comerciais. Apesar disto, o inchamento em espessura foi compatível com o dos painéis de partículas de madeira existentes no mercado. Os painéis nos quais se aplicou a solução de poliestireno foram, de modo geral, os que apresentaram os melhores valores para todas as propriedades.This work aimed determine the properties of wood particleboards containing particles of polystyrene (PS) and polyethylene therephthalate (PET). Three amounts of polystyrene (0, 25 and 50%), two amounts of PET/PS (5/20 and 10/40%), three amounts (0, 4 and 6%) of urea-formaldehyde or phenol-formaldehyde adhesive and three amounts of polystyrene in toluene solution (0, 4 and 6%), combined with 50, 75 or 100% of particles of Pinus elliottii wood were used. Layer boards measuring approximately 400 x 400 x 10 mm with density approximately equal to 0.60 g/cm³ were produced. Internal bond, rupture and elasticity modulus, screw withdrawal, water absorption and thickness swelling after 24 hours of immersion were determined. The mechanical properties of all the boards were superior to the established by ANSI/A 208.1-1993 standard. All wood/plastic particleboards absorbed more water than those observed in commercial boards. However, the observed thickness swelling was quite similar to the values of commercial wood particleboards. Boards in which the solution of polystyrene was applied presented, in general, the best values for all the properties.

O objetivo deste trabalho foi determinar o rendimento em madeira serrada, bem como a massa específica, contração volumétrica, resistência à flexão estática, resistência à compressão paralela, qualidade da linha de cola e trabalhabilidade das madeiras de Eucalyptus grandis, Eucalyptus saligna e Pinus elliottii. Foram colhidas três árvores de cada uma destas espécies, com idades aproximadas de 50, 40 e 40 anos, respectivamente. De cada árvore foram retiradas três toras, sendo uma na base, uma no meio e uma no topo do fuste. Foram analisadas as variações em algumas propriedades, no sentido medula-casca e no sentido longitudinal. Os resultados mostraram que todas as propriedades físicas e mecânicas variaram dentro da árvore nos sentidos radial e longitudinal. A densidade básica e as resistências à flexão e à compressão aumentaram na direção medula-casca, enquanto a contração volumétrica diminuiu. Portanto, para obtenção de madeiras mais densas, mais estáveis e com maior resistência à flexão e à compressão, é necessária a colheita de árvores mais velhas. Observou-se ainda que as toras da porção média do fuste, de modo geral, apresentaram menores valores para todas as propriedades determinadas do que as da base e do topo. A resistência da linha de cola e a porcentagem de falha na madeira para madeira juvenil e adulta apresentaram pouca diferença em todas as posições no fuste. No ensaio de confecção de espiga e furação para espiga, todas as espécies apresentaram resultados satisfatórios, sem ocorrência de defeitos.

O objetivo deste trabalho foi a produção de adesivos para madeira a partir de creosoto desmetilado. Para isto, foram sintetizadas diferentes formulações de adesivos para madeira a partir de creosoto desmetilado e paraformaldeído, variando-se o pH inicial da formulação (12,00, 12,25, 12,50, 12,75, 13,00, 13,25 e 13,50) e a temperatura de síntese (60 e 70 °C), para possibilitar a verificação dos melhores pHs e da melhor temperatura para elaboração do adesivo. Foi verificado, por meio da avaliação do gel time, que a melhor temperatura de síntese foi 70 °C. Foram realizadas, então, análises por DSC (calorimetria diferencial exploratória), para obtenção dos parâmetros cinéticos e caracterização das formulações adesivas de creosoto desmetilado sintetizadas a 70 °C. Os adesivos foram utilizados para colagem, a quente (160 °C) e sob pressão (12 kgf/cm²), de lâminas de Araucaria angustifolia. Após a colagem, foram realizados os ensaios de resistência mecânica ao cisalhamento por tração, para condição seca e úmida. Verificou-se que a resistência da linha de cola e a porcentagem de falha na madeira para os adesivos de creosoto desmetilado sintetizados a 70 °C foram inferiores às do adesivo de fenol-formaldeído sintetizado em laboratório, que foi utilizado como padrão.

O objetivo deste trabalho foi analisar a cinética de cura de adesivos à base de taninos de Eucalyptus grandis, Eucalyptus saligna e Eucalyptus urophylla por calorimetria diferencial exploratória (DSC), comparando-a com a cinética de cura de adesivos comerciais: fenol-formaldeído e de taninos de acácia-negra (Acacia mollissima D.Wild). Verificou-se que o adesivo de taninos de Eucalyptus urophylla apresentou os parâmetros cinéticos (energia de ativação, entalpia, temperatura de pico e ordem de reação) mais próximos aos do adesivo comercial de taninos de acácia-negra, que foram totalmente diferentes do adesivo à base de fenol-formaldeído. Com base nestes parâmetros constatou-se que, em relação aos outros dois, o adesivo de taninos de Eucalyptus urophylla é o mais adequado para colagem, uma vez que em condições industriais ele necessitará de uso mínimo de energia e de tempo de prensagem durante o processo de colagem.

This study has shown that Eucalyptus tar and creosote can be used in phenolic adhesive formulations (resols) for wood products bonding. Some adhesives were prepared substituting 0; 17.7; 35.0 and 67.0% of the phenol by anhydrous tar and 0; 15.0 e 28.5% by creosote. In gluing Brazilian pine veneers, eucalypt tar and creosote based adhesives required longer pressing times for curing than conventional phenol-formaldehyde adhesives. By using 13C NMR, the number of carbons in side chains and hydroxyl, carbonyl, carboxyl and methoxyl groups related to 100 aromatic rings could be estimated in tar and creosote. In creosote, after reaction with excess formaldehyde in alkaline medium, only 0,28 hydroxymethyl groups was detected per phenolic ring. This low amount of hydroxymethylation explains the lack of reactivity in curing observed when creosote was introduced in a standard adhesive formulation.

This study aimed to evaluate the potential use of waste generated by forestry species that occur in semiarid northeastern at Seridó region, Rio Grande do Norte, for the briquettes production, determine the physical and mechanical briquettes properties, and to correlate the wood density with the density after the briquettes production and briquettes density with the compressive strength. Thirty-two trees were collected (eight species with four replications). The wood physical and chemical properties evaluation were held under a completely randomized design. For the variables related to briquette, it was adopted the same design with three replicates for each species, totalizing 24 sampling units. The briquettes produced with jurema-preta wood stood out as a function to higher fixed carbon content, calorific value and higher compressive strength flat. The briquettes made from waste of imburana wood had the worst performances for the studied parameters. It was observed a negative correlation between the wood density and the gain of apparent relative density of the briquettes and a positive correlation between the briquettes density and the compressive strength of flat. Esse trabalho teve como objetivos avaliar o potencial de aproveitamento de resíduos gerados pela exploração florestal de espécies que ocorrem no semiárido brasileiro na região do Seridó, Estado do Rio Grande do Norte, para a produção de briquetes, determinar as propriedades físicas e mecânicas dos briquetes, correlacionar a densidade da madeira com a densidade após a produção dos briquetes, e a densidade dos briquetes com a resistência à compressão. Foram coletadas 32 árvores (oito espécies com quatro repetições). A avaliação das propriedades físicas e químicas entre as madeiras foram realizadas segundo um delineamento inteiramente casualizado. Para as variáveis relacionadas aos briquetes, adotou-se o mesmo delineamento, com três repetições por espécie, totalizando 24 unidades amostrais. Os briquetes produzidos com a madeira de jurema-preta se destacaram em função dos maiores teores de carbono fixo, poder calorífico, e resistência à compressão plana. Os briquetes produzidos com os resíduos da madeira de imburana apresentaram os piores desempenhos para os parâmetros estudados. Foi observada correlação negativa entre a densidade básica das madeiras e o ganho de densidade relativa aparente dos briquetes e correlação positiva entre a densidade aparente dos briquetes e a resistência à compressão plana.doi: 10.4336/2011.pfb.31.68.285

Esse trabalho teve como objetivos avaliar o potencial de aproveitamento de resíduos gerados pela exploração florestal de espécies que ocorrem no semiárido brasileiro na região do Seridó, Estado do Rio Grande do Norte, para a produção de briquetes, determinar as propriedades físicas e mecânicas dos briquetes, correlacionar a densidade da madeira com a densidade após a produção dos briquetes, e a densidade dos briquetes com a resistência à compressão. Foram coletadas 32 árvores (oito espécies com quatro repetições). A avaliação das propriedades físicas e químicas entre as madeiras foram realizadas segundo um delineamento inteiramente casualizado. Para as variáveis relacionadas aos briquetes, adotou-se o mesmo delineamento, com três repetições por espécie, totalizando 24 unidades amostrais. Os briquetes produzidos com a madeira de jurema-preta se destacaram em função dos maiores teores de carbono fixo, poder calorífico, e resistência à compressão plana. Os briquetes produzidos com os resíduos da madeira de imburana apresentaram os piores desempenhos para os parâmetros estudados. Foi observada correlação negativa entre a densidade básica das madeiras e o ganho de densidade relativa aparente dos briquetes e correlação positiva entre a densidade aparente dos briquetes e a resistência à compressão plana. doi: 10.4336/2011.pfb.31.68.285