Wood Scinece /waste Recycling

Wood wastes are one of the leading contributors of greenhouse gases cum climate change. While the burning of wood wastes results in CO2 emission, decomposition generates methane. In place of these emissions, wood wastes can be converted into biochars which have a lot of novel applications. However, low biochar yield was the common limitation of wood wastes, essentially, due to a mixture of different classifications of trees that pyrolyse at different conditions. In this study, biochar yield from sorted wood wastes was optimised by varying pyrolysis temperature and time. Power consumption, cost, and carbon footprint of the optimised biochar and ash were compared for both hydropower grid and diesel generator scenarios. Optimal pyrolysis yields were 33.6 % (400 °C), 29.4 % (350 °C) and 18.5 % (400 °C) respectively for hardwood sawdust char (HSC), softwood sawdust char (SSC), and mixed sawdust char (MSC) at 2 hours duration for all materials. The CO2 emissions from ash were 2.49 kg and ...

Brazil has experienced a crescent seek for housing alternatives in relation to masonry, and the wooden houses have demonstrated as a very rational and sustainable possibility. However, the production of building parts and components can present environmental liabilities, both if the timber companies which compose this chain do not have efficient plans for the management of their generated waste and if these companies do not present technologically advanced production lines. These wood-based wastes from the civil construction activities are found in the pure and natural modes or through the chemical modification of wood. Both residual examples can pollute and result in irreversible environmental problems if assertive actions are not applied for their control and discard. Nevertheless, this study aims to discuss the problem about the topic of wooden waste from civil construction, as well as share proposals to help in the mitigation of this Brazilian current question.

O aumento da disponibilização de resíduos gerados pelas indústrias madeireiras gera um problema para a cadeia produtiva, pois, muitas vezes, estes resíduos são depositados em locais inadequados ou são reutilizados de modo errado. O presente trabalho teve como objetivo a concepção de pequenos objetos de madeira com o enfoque de reaproveitar resíduos lignocelulósicos, provenientes de processos industriais. Os objetos produzidos foram um cesto, uma migalheira e um suporte para computadores pessoais portáteis. A proposta de uso de resíduos de madeira procurou agregar valor aos mesmos, sustentabilidade no processo de produção do produto, além do aspecto ambiental, que buscou minimizar à disposição dos resíduos no meio ambiente de forma indiscriminada. A confecção destes produtos é simples e requer baixa qualificação de mão-de-obra, fator que promove a geração de trabalho e de renda para artesãos de pequenos empreendimentos econômicos solidários, como é o caso da parceria estabelecida com a marcenaria de mulheres, localizada no assentamento rural de Pirituba.

Composites made of recycled low density polyethylene and wood or bark flour of Pinus radiata D. Don were tested, the effect of the flour content and density of the composites on physical and mechanical properties were determinated. These both types of composites were prepared by injection moulding and without chemical additives at 20/80, 40/60 and 60/40 of flour/polyethylene (w/w). Several physical and mechanical properties were measured. The results were tested for comparison of means and Multiple Linear Regression Analysis (ARLM), followed by the method stepwise (SWM). The results indicate that the physical properties and the E increased with increasing flour content, while the tensile strength and the hardness tended to decline. The composites made with bark flour had higher stiffness, absorbed less water and swelled less, and show similar hardness than the composite made with wood flour, but only the composite with 20% (w/w) of bark flour showed greater tensile strength than the others composites. The content of flour was the variable that most affects the properties evaluated, except to the E and the hardness of the wood flour composites, they were most affected by their density.

Wood products follow the same cycle as other materials: manufacture, use and disposal. For certain applications, chemical additives are added to wood to increase its durability against biological and physical attack. At the end of life, waste wood is chipped or crushed before being recovered as raw material for new products or as fuel for energy. In recycled wood, there is the potential that some wood particles are contaminated by hazardous substances, such as organic or heavy metal preservatives. erefore there is a need for a quality control method of assessing recovered wood that is on the one hand su ciently precise and on the other not too expensive to preclude the use of recycling wood in to new products. is paper covers some preliminary research that is part of a large study that aims to develop a robust analytical method for recovered wood. However the extreme variability of recovered wood makes it di cult to develop such protocols on real recovered wood samples. Consequently, model chip piles with known contamination levels were created to simulate real world recovered wood samples.