DEVELOPMENT OF A MACHINE FOR CHOPPING WOOD RESIDUES

CAD software and FEM analysis were used to modify the drum of threshing machine into machine for chopping wood residues. The operating parameters that affecting the performance of the chopping machine are drum speed (450, 1000 and 1200 rpm), three stages of serrated disk arrangement clearance between drum flail knives (0.7, 1.5 and 3 cm) and three levels of feeding capacity (W1 􀵌 300, W2 = 360 and W3 = 420 kg.h-1). The developed machine was operated by the addition of two types of knives (sharp free knives + serrated discs) to the original knife existing already in the machine. The machine was evaluated in terms of production capacity, cutting efficiency, power requirements and energy consumption. Using the modified (serrated) saw disk mill and flail knives reduced the energy requirement for chopping and raised fine degree of the chopped materials and solve the clogging problem. The cutting productivity and cutting efficiency raised with reducing the clearance between flail knives (0.7, 1.5 and 3 cm) while the power requirements and energy consumption reduced.

PRODUÇÃO DE MÓVEIS RÚSTICOS COM MADEIRA RESIDUAL DA FLORESTA AMAZÔNICA

A exploração madeireira e as conversões de áreas de florestas para uso alternativo do solo na região Amazônica, em especial no estado do Amapá, resultam em grandes quantidades de madeira residual que em geral são abandonadas em campo. Essa problemática da geração de resíduos florestais e principalmente do desperdício e da falta de alternativas para o seu uso apropriado, resultou nesta proposta de pesquisa que teve como objetivo a produção de móveis rústicos artesanais como uma alternativa para o uso da madeira residual da floresta Amazônica. Foram coletados resíduos de madeira deixados no campo após a colheita de floresta Amazônica manejada, destinando-os à fabricação de mobiliário rústico, obtendo como resultado final os seguintes protótipos: banco peça de tora única, balcão para barzinho, aparador de madeira, pia de madeira, mesinha de centro com tampo de madeira, mesinha de centro com tampo de vidro. Foi testada a viabilidade técnica para fabricação artesanal das peças de mobiliário utilizando máquinas e ferramentas portáteis. Os resíduos de madeira se mostraram excelente fonte de matéria-prima para movelaria rústica possibilitando múltiplas alternativas de designs, apesar de certas dificuldades terem sido evidenciadas no decorrer do processo como: peso, dureza, orientação da grã da madeira, entre outras que, no entanto, não impossibilitaram a produção dos móveis. O uso da madeira residual para fabricação de móveis rústicos pode se constituir num novo e empreendedor negócio para a região Amazônica, contribuindo para a geração de renda local. Verificou-se que o método empregado proporcionou a produção de móveis originais, o que agrega valor à sua comercialização. Palavras-chave: trabalho artesanal; empreendedorismo; projeto. Rustic furniture production with wood residues from the Amazon forest ABSTRACT: Harvesting and conversions of forest areas to alternative land use in the Amazon region, especially in the Amapá state, result in large amounts of wood residues that are generally abandoned. This problem about the forest residues and mainly of its loss and the lack of alternatives for its proper use, resulted in this research proposal that aimed to produce handcrafted rustic furniture as an alternative to the use of wood residues from the Amazon forest. Wood residues left in the field after harvesting the managed Amazon forest were collected and destined for the manufacture of rustic furniture, obtaining the following prototypes as a final result: log bench, bar counter, wood dresser, wood sink, coffee table with wood top, coffee table with glass top. The technical feasibility of handcrafting furniture pieces using portable machines and tools were tested. Wood residues proved to be an excellent source of raw material for rustic furniture, enabling multiple design alternatives, although certain difficulties were evidenced during the process such as: weight, hardness, wood grain orientation, among others that did not prevent the furniture production. The use of wood residues to rustic furniture manufacture can constitute a new and entrepreneurial business for the Amazon region, contributing to the generation of local income. It was found that the method used provided the production of original furniture, which adds value to its marketing. Keywords: artisan work; entrepreneurship; design.

Innovative wood use can enable carbon-beneficial forest management in California

Responsible stewardship of temperate forests can address key challenges posed by climate change through sequestering carbon, producing low-carbon products, and mitigating climate risks. Forest thinning and fuel reduction can mitigate climate-related risks like catastrophic wildfire. These treatments are often cost prohibitive, though, in part because of low demand for low-value wood “residues.” Where treatment occurs, this low-value wood is often burned or left to decay, releasing carbon. In this study, we demonstrate that innovative use of low-value wood, with improved potential revenues and carbon benefits, can support economical, carbon-beneficial forest management outcomes in California. With increased demand for wood residues, forest health–oriented thinning could produce up to 7.3 million (M) oven-dry tonnes of forest residues per year, an eightfold increase over current levels. Increased management and wood use could yield net climate benefits between 6.4 and 16.9 million tonnes of carbon dioxide equivalent (M tCO2e) per year when considering impacts from management, wildfire, carbon storage in products, and displacement of fossil carbon-intensive alternatives over a 40-y period. We find that products with durable carbon storage confer the greatest benefits, as well as products that reduce emissions in hard-to-decarbonize sectors like industrial heat. Concurrently, treatment could reduce wildfire hazard on 4.9 M ha (12.1 M ac), a quarter of which could experience stand-replacing effects without treatment. Our results suggest that innovative wood use can support widespread fire hazard mitigation and reduce net CO2 emissions in California.

Agronomic Effects of Tectona grandis Biochar from Wood Residues on the Growth of Young Cedrela odorata Plants in a Nursery

Biochar from agroforestry biomass residues is an alternative source of fertilizers for improving the soil fertility. In Costa Rica, Cedrela odorata is planted in pure plantations and agroforestry systems and different types of substrates are used in the nursery to enhance the growth and performance of the young saplings. The main objective of the present study was to evaluate the growth (in height, diameter, biomass) and distribution of carbon (C), hydrogen (H), and nitrogen (N) for C. odorata plants in a nursery with different application rates of biochar produced from Tectona grandis wood residues. The results showed that the above-measured variables were statistically affected by different application rates of the biochar. The stem diameter, total height, number of leaves, and height increment were statistically significantly higher in the substrate with an application rate of 25–50 tons/ha, in contrast to the 0 and 75 tons/ha application rates, which were statistically the lowest. As for the levels of C, H, and N, there were differences, with the highest values of N and C being in the leaves and stem with the 50 tons/ha application rate and the highest values of H for the 75 tons/ha application rate. The above results showed that applying biochar obtained from T. grandis residues improved soil conditions, resulting in better growth of C. odorata saplings with an application rate of 25 and 50 tons/ha.

Effect of Pyrolysis Temperature and Wood Species on the Properties of Biochar Pellets

Thermal treatments such as torrefaction and fast pyrolysis are commonly employed methods to produce biofuels with high-energetic properties. In this study, wood chips were heat-treated at different temperatures of torrefaction (315 °C) and fast pyrolysis (400 and 454 °C) to form energetic pellets. Three softwoods, jack pine (JP), balsam fir (BF), and black spruce (BS), were evaluated. Pellets are produced using 20% moisture content and 15% pyrolytic lignin as a binder. Untreated- and treated-wood residues were characterized by surface chemistry, elemental analysis, and chemical composition, whereas all pellets were characterized in terms of density, high heat value (HHV), and durability. Results showed that both thermal treatments caused significant changes in the physicochemical structure of wood residues. Using temperatures higher than 315 °C leads to the disappearance of hydroxyl groups, a decrease in oxygen and hydrogen contents, and an increase in carbon content. Regardless of the treatment temperature, pellets made from heat-treated JP had the best durability (93%). In contrast, the calorific values of wood-treated pellets reached up to 31 MJ/kg, compared to untreated-wood pellets (19 MJ/kg). Thus, the densification of the thermal-treated wood residues represents a potential approach for producing biofuels with high energetic value.

Analysis on the Use of Briquettes as an Alternative to Improve the Generation of Thermal Energy in the Locality of Aripuana-Brazil

The city of Aripuana is one of the largest wood producer in the state of Mato Grosso, Brazil. Wood residues are used in the electricity generation at three thermoelectric plants in this region. However, the plants have high costs in transporting the wood residues (due to poor road conditions). Hence, this paper compares the energy performance of wood residues in natura and compacted as briquettes by calculating the heating value and determining the influence of moisture content on the energy characteristics of wood residues. The goal is to demonstrate the viability of using briquettes in order to improve thermoelectric generation. The wood residues from this region are affected by the high humidity of the biome. An alternative to improve the use of energy contained in the wood residues is to produce briquettes with lower humidity. This allows one to maintain high levels of heat energy in a lower volume, facilitating handling and storage. The results show that the use of briquettes improved the performance of thermoelectric plants, generating 1 MW of electricity power with less than 1 ton of briquettes. This contributes to the preservation of the environment, reducing operating costs, transportation and storage of the raw materials.

Wood Residues in the Moratuwa Woodworking Industry Cluster of Sri Lanka: Potential for Sector Synergies and Value-Added Products

The Moratuwa Woodworking Industry Cluster (MWIC) is a geographically concentrated cluster of over 1,600 small-to-medium scale wood-based manufacturing and retail facilities in Sri Lanka. Firms include furniture manufacturers, carpentry shops, sawmills, and integrated sawmills. The concept of industrial symbiosis explores the synergies between industrial facilities to exchange energy, water, by-products, and waste to achieve a higher efficiency in resource utilization. This research was undertaken to address the lack of quantitative information on wood residues generated within the MWIC. A survey of 180 primary and secondary wood product manufacturers was undertaken to quantify MWIC firm by-product production and consumption of wood residues to establish a baseline for possible end use and waste synergies. The total population of enterprises generating wood waste is 730; retail facilities are not included. Sawmills produce approximately 66% of the 6,490 MT of MWIC's monthly wood residue generation, with the balance produced by carpentry and integrated enterprises. Teak (Tectona grandis) and mahogany (Swietenia macrophylla) are the dominant species used in the MWIC, accounting for most of the wood waste. Three main types of wood waste were identified in the survey: sawdust (76.5%), boards with significant wane (16.5%) unusable for further products, and offcuts (6.9%). Only 55% of the wood waste generated in MWIC is currently used; the remaining 45% is taken to landfills or disposed of in other ways, such as discarded in waterways or other nonapproved locations. Improved wood waste sorting by type at the mill level and aggregated wood waste within the MWIC was determined to increase the usability of wood waste as potential inputs in other wood manufacturing sectors in the MWIC.

ASSESSMENT OF ECOLOGICAL AND ECONOMIC EFFICIENCY OF COMPOSITE FUEL PRODUCTION FROM THE PEAT AND BIOMASS

The goal of investigation was assessment of environmental impact and economic efficiency of composite briquette production on the base of peat and renewable biomass. Biomass for composite briquettes was obtained from straw (cereal crops and rape) and wood residues (sawdust, chips) Experimental composite briquette were produced from the mixture of peat and biomass in relation to – 25 : 75, 50 : 50, 75 : 25. The technological cards of biomass feedstock production for 6 variants were developed. Technological cards were used for calculation of emission into the atmosphere during life cycle of biomass production and prime cost of biomass. The lowest volume of gas (SO2, NOx, CO2) and particulate matter (PM) emission was installed for biomass production from the sawdust. The highest volume of emission was installed for production of biomass from the straw with pressing it in standard bale. The volume of CO2 emission for the sawdust production was 6 kg per ton of biomass and for the standard bale of straw was 19 kg per ton of biomass. Prime cost of sawdust production (lowest) was 11 belarusian rubles per ton of biomass, for the wood chips was 19 rubles per ton and for the straw varied from 26 to 33 rubles per ton in depend of technology. It was installed that growth of biomass rate in composite briquette had a good influence on number of basic fuel characteristics (contents of ash, sulfur and moisture). The variation of calorific value of briquette was not significant in depend of biomass contents. In accordance with assessment of all characteristics the better briquettes was obtained from the peat and sawdust.