Brazil has 8.51 million km 2 of territorial area and a tropical climate. In 2010, the occupation of the Brazilian soil consists of 20.8% pasture, 6.8% agriculture, 0.8% forested areas, 61.0% natural forests, and 9.7% other areas. In 2012, of the total area of the country 3.25% (27.65 million ha) is occupied by soy bean cultivation and 1% (8.5 million ha) by sugar cane cultivation. In 2012, the main cultivated species in the country were Eucalyptus spp. (71.0%), Pinus spp. (21.75%), Acacia mearnsii and Acacia mangium (2.12%), Hevea brasiliensis (2.36%), and Schizolobium amazonicum (1.22%). From 2004 to 2012, the planted forest area growth was 50.4%. The main factor that boosted this growth was the demand of the pulp and paper, followed by wood-based panels sector. It is also notable the development of new planted forests in Brazil for energy purposes. In recent decades, scientific and technological advance shave resulted in significant improvements in productivity, resistance to diseases, uniform degree of the forest plantations, wood quality etc. Among the most researched species are the ones belonging to Eucalyptus gender for having excellent adaptability to the edaphoclimatic conditions in the country. The current average productivity of Eucalyptus is of 40.7 m 3 /ha·year. In some regions of the country the average productivity of Eucalyptus has reached 100 m 3 /ha·year. The Brazilian forestry industry uses mainly planted forests, and the pulp and paper industry consumes only this type of wood. The pulp and wood panel sectors are more technologically advanced in relation to the other wood products sectors.
RESUMOA fim de melhorar a eficácia global da produção de energia, uma estratégia é o modelo de biorrefinarias, em que todos os componentes de biomassa são totalmente utilizados para produzir uma gama de produtos de maior valor agregado. A lignina kraft é um dos produtos oriundos do processo de produção de celulose e que pode ser utilizado na confecção de materiais densificados. O objetivo deste trabalho foi avaliar o comportamento da adição da lignina extraída do licor negro kraft em briquetes confeccionados com resíduos da indústria moveleira na forma de maravalha e partículas de painéis; em diferentes proporções. Os briquetes foram produzidos em briquetadeira laboratorial, usando as temperaturas de 60, 75 e 90 o C. O tempo de compactação e resfriamento foi de 5 minutos e pressão 68,9 x 10 5 N.m -2 (1000 PSI). A qualidade dos briquetes foi avaliada em função da determinação da propriedade mecânica. Determinou-se a carga de ruptura dos briquetes. A adição de lignina kraft aos resíduos de madeira nas proporções e temperatura adequadas apresentou vantagens de aumento de resistência mecânica dos briquetes. A lignina kraft apresentou vantagens como aglutinante na produção de briquetes de resíduo de madeira na temperatura de compactação de 90 °C com adição de 20% de lignina kraft e temperaturas de 60 e 75 °C de compactação na proporção de adição de 40 e 60% de lignina kraft, respectivamente. Palavra-chave: briquetes; aglutinante; resíduo indústria moveleira.
RESUMOEste trabalho teve como objetivo avaliar chapas de partículas do tipo aglomerado convencional, chapas tipo Medium Density Particleboard (MDP) e as do tipo aglomerado com inclusão laminar. As chapas avaliadas foram fabricadas com partículas de Acacia mangium e no aglomerado com inclusão laminar utilizaram-se lâminas de Schizolobium amazonicum. O aglomerado convencional e o aglomerado com inclusão laminar apresentaram umidade de equilíbrio higroscópico estatisticamente superior ao MDP. O aglomerado com inclusão laminar apresentou maior índice de inchamento em espessura após duas horas de imersão em água, valores de módulo de ruptura em flexão estática maiores e maior resistência ao arrancamento de parafuso. As chapas do tipo MDP apresentaram maior resistência à tração perpendicular. Não foram observadas diferenças significativas nas demais propriedades. Conclui-se que a inclusão laminar melhorou o módulo de ruptura e o arrancamento de parafuso, enquanto a utilização de partículas finas nas faces melhorou as propriedades físicas das chapas.Palavras-chave: aglomerado convencional, painel de partículas de média densidade, inclusão laminar. Effect of Particleboard Type in Physical and Mechanical Properties ABSTRACTThis study aimed to evaluate physical and mechanical properties of conventional agglomerate, medium density particleboard and agglomerate with laminate inclusion. Particleboards were made of Acacia mangium particles and laminas of Schizolobium amazonicum were used to produce agglomerate with laminate inclusion. Conventional agglomerate and agglomerate with laminate inclusion showed hygroscopic equilibrium moisture statistically superior to MDP. Agglomerate with laminate inclusion showed the highest rate of thickness swelling after 2 hours of immersion in water, the highest modulus of rupture in bending strength and the best screw withdraw resistance. MDP presented the highest mean value of board internal bond strength. There were no significant differences in other evaluated properties. It was concluded that laminate inclusion improved modulus of rupture and screw withdraw resistance while the use of fine particles on the faces improved physical properties of the particleboards.
The hot acid hydrolysis followed by chlorine dioxide (A/D*) and hot chlorine dioxide (D*) technologies have proven very useful for bleaching of eucalyptus kraft pulp. Although the characteristics and biodegradability of effluents from conventional chlorine dioxide bleaching are well known, such information is not yet available for effluents derived from hot acid hydrolysis and hot chorine dioxide bleaching. This study discusses the characteristics and biodegradability of such effluents. Combined whole effluents from the complete sequences DEpD, D*EpD, A/D*EpD and ADEpD, and from the pre-bleaching sequences DEp, D*Ep, A/D*Ep and ADEp were characterized by quantifying their colour, AOX and organic load (BOD, COD, TOC). These effluents were also evaluated for their treatability by simulation of an activated sludge system. It was concluded that treatment in the laboratory sequencing batch reactor was efficient for removal of COD, BOD and TOC of all effluents. However, colour increased after biological treatment, with the greatest increase found for the effluent produced using the AD technology. Biological treatment was less efficient at removing AOX of effluents from the sequences with D*, A/D* and AD as the first stages, when compared to the reference D stage; there was evidence of the lower treatability of these organochlorine compounds from these sequences.
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