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Thermally Modified Wood
Thermally modified wood is wood that has been modified by a controlled pyrolysis process of wood being heated in absence of oxygen inducing some chemical changes to the chemical structures of cell wall components (lignin, cellulose and hemicellulose) in the wood in order to increase its durable good, durability. Low oxygen content prevents the wood from burning at these high temperatures. Several different technologies are introduced using different media including nitrogen gas, steam and hot oil. Modification processes The first technological approach of thermal modification processes of wood is the paper of Burmester. There are five different thermal modification processes: Thermowood (or Premium wood) in Finland, Retification process (Retiwood, New Option Wood) and Les Bois Perdure in France, Plato process in Netherlands, Oil-heat treatment in Germany (OHT-Process), Westwood Process and the AlphaInterloc processes are proprietary process technologies in USA. Description of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Durable Good
In economics, a durable good or a hard good or consumer durable is a good that does not quickly wear out or, more specifically, one that yields utility over time rather than being completely consumed in one use. Items like bricks could be considered perfectly durable goods because they should theoretically never wear out. Highly durable goods such as refrigerators or cars usually continue to be useful for several years of use, so durable goods are typically characterized by long periods between successive purchases. Durable goods are known to form an imperative part of economic production. This can be exemplified from the fact that personal expenditures on durables exceeded the total value of $800 billion in 2000. In the year 2000 itself, durable goods production composed of approximately 60 percent of aggregate production within the manufacturing sector in the United States. Examples of consumer durable goods include bicycles, books, household goods (home appliances, consumer e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Resources Research Institute
The Natural Resources Research Institute (NRRI) is a United States (U.S.) based research institute founded by the Minnesota state legislature within the University of Minnesota Duluth. NRRI is a non-profit, applied research organization, established with a mission to improve the economy of Minnesota. The Institute aims to help launch small businesses and provides ongoing research and development assistance. History The mid- to late-1970s and early-1980s were particularly difficult times for Minnesota's natural resource-based industries, especially for the taconite mining industry. In the face of a domestic steel crisis, shipments of iron ore from Northeastern Minnesota's eight taconite plants plummeted. Growth in the taconite industry, which had begun in the 1950s, ended and employment in this critical base industry dropped from about 16,000 to 3,000. About 2,000 supply companies on the Iron Range, in Duluth and elsewhere in the state were also critically impacted. Perhaps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Softwood
file:Pinus sylvestris wood ray section 1 beentree.jpg, Scots Pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. The main differences between hardwoods and softwoods is that the structure of hardwoods lack resin canals, whereas softwoods lack pores (though not all softwoods have resin canals). Characteristics Softwood is wood from gymnosperm trees such as pines and spruces. Softwoods are not necessarily softer than hardwoods. In both groups there is an enormous variation in actual wood hardness, the range of density in hardwoods completely including that of softwoods. Some hardwoods (e.g. balsa) are softer than most softwoods, while the hardest hardwoods are much harder than any softwood. The woods of longleaf pine, Douglas fir, and Taxus, yew are much harder in the mechanical sense than several hardwoods. Softwoods are generally most used by the construction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torrefaction
Torrefaction of biomass, e.g., wood or grain, is a mild form of pyrolysis at temperatures typically between 200 and 320 °C. Torrefaction changes biomass properties to provide a better fuel quality for combustion and gasification applications. Torrefaction produces a relatively dry product, which reduces or eliminates its potential for organic decomposition. Torrefaction combined with densification creates an energy-dense fuel carrier of 20 to 21 GJ/ton lower heating value (LHV). Torrefaction makes the material undergo Maillard reactions. Torrefied biomass can be used as an energy carrier or as a feedstock used in the production of bio-based fuels and chemicals. Biomass can be an important energy source. However, there exists a large diversity of potential biomass sources, each with its own unique characteristics. To create efficient biomass-to-energy chains, torrefaction of biomass, combined with densification ( pelletisation or briquetting), is a promising step toward ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemicellulose
A hemicellulose (also known as polyose) is one of a number of heteropolymer, heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all embryophyte, terrestrial plant cell walls.Scheller HV, Ulvskov Hemicelluloses.// Annu Rev Plant Biol. 2010;61:263-89. doi: 10.1146/annurev-arplant-042809-112315. Cellulose is crystalline, strong, and resistant to hydrolysis. Hemicelluloses are branched, shorter in length than cellulose, and also show a propensity to crystallize. They can be hydrolyzed by dilute acid or Base (chemistry), base as well as a myriad of Cellulase, hemicellulase enzymes. Composition Diverse kinds of hemicelluloses are known. Important examples include xylan, glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan. Hemicelluloses are polysaccharides often associated with cellulose, but with distinct compositions and structures. Whereas cellulose is derived exclusively from glucose, hemicelluloses are composed of diverse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fiber is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%. Cellulose is mainly used to produce paperboard and paper. Smaller quantities are converted into a wide variety of derivative products such as cellophane and rayon. Conversion of cellulose from energy crops into biofuels such as cellulosic ethanol is under development as a renewable fuel source. Cellulose for industrial use is mainly obtained from wood pulp and cotton. Some animals, particularly ruminants and termites, can digest cellulose with the help of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors. History Lignin was first mentioned in 1813 by the Swiss botanist A. P. de Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid. He named the substance “lignine”, which is derived from the Latin word '' lignum'', meaning wood. It is one of the most abundant organic polymers on Earth, exceeded only by cellulose. Lignin constitutes 30% of non-fossil organic carbon on Earth, and 20 to 35% of the dry mass of wood. Lignin is present in red algae, which suggest that the common ancestor of plants and red algae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
