Search results
Results from the WOW.Com Content Network
This process is known as secondary growth; it is the result of cell division in the vascular cambium, a lateral meristem, and subsequent expansion of the new cells. These cells then go on to form thickened secondary cell walls, composed mainly of cellulose, hemicellulose and lignin. Where the differences between the seasons are distinct, e.g.
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. [1] 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. [2]
Wood science [1] is the scientific field which predominantly studies and investigates elements associated with the formation, the physical and chemical composition, and the macro- and microstructure of wood as a bio-based and lignocellulosic material.
The by-products from the wood processing industry are called wood processing residues and consist of cut offs, shavings, sawdust, bark, and black liquor. [27] Wood processing residues have a total energy content of 5.5 EJ annually. [28] Wood pellets are mainly made from wood processing residues, [m] and have a total energy content of 0.7 EJ.
Charcoal briquettes, often made from compressed sawdust or similar, in use. Carbon and carbon-rich materials have desirable properties but are nonvolatile, even at high temperatures. Consequently, pyrolysis is used to produce many kinds of carbon; these can be used for fuel, as reagents in steelmaking (coke), and as structural materials.
Carbohydrates that are composed of carbon, hydrogen, and oxygen and range in complexity from relatively simple sugars to large molecules of cellulose. Fats that are composed of glycerids of fatty acids, like butyric, stearic, and oleic. They also include carbon, oxygen, and hydrogen. Lignins are complex compounds from the older wood parts. They ...
Molecules with very small chain length resulting from the breakdown of cellulose are known as cellodextrins; in contrast to long-chain cellulose, cellodextrins are typically soluble in water and organic solvents. The chemical formula of cellulose is (C 6 H 10 O 5) n where n is the degree of polymerization and represents the number of glucose ...
Cellulosic sugars are derived from non-food biomass (e.g. wood, agricultural residues, municipal solid waste). [1] The biomass is primarily composed of carbohydrate polymers cellulose, hemicellulose, and an aromatic polymer (lignin). The hemicellulose is a polymer of mainly five-carbon sugars C 5 H 10 O 5 .