Search results
Results from the WOW.Com Content Network
There are many ways to obtain hemicellulose; all of these rely on extraction methods through hardwood or softwood trees milled into smaller samples. In hardwoods the main hemicellulose extract is glucuronoxlyan (acetylated xylans), while galactoglucomannan is found in softwoods.
The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. The technology entails several steps, both mechanical and chemical. It is the dominant method for producing paper.
White liquor consists mainly of sodium hydroxide and sodium sulfide in water and is the active component in Kraft pulping. [1] White liquor also contains minor amounts of sodium carbonate, sodium sulfate, sodium thiosulfate, sodium chloride, calcium carbonate and other accumulated salts and non-process elements.
In industrial paper-making processes, organosolv is a pulping technique that uses an organic solvent to solubilise lignin and hemicellulose. It has been considered in the context of both pulp and paper manufacture and biorefining for subsequent conversion of cellulose to fuel ethanol.
Xylan (/ ˈ z aɪ l æ n /; [3] / ˈ z aɪ l ən / [4]) (CAS number: 9014-63-5) is a type of hemicellulose, a polysaccharide consisting mainly of xylose residues. It is found in plants, in the secondary cell walls of dicots and all cell walls of grasses. [5]
Black liquor as used for gasification. New waste-to-energy methods to recover and utilize the energy in the black liquor have been developed. [citation needed] The use of black liquor gasification has the potential to achieve higher overall energy efficiency than the conventional recovery boiler, while generating an energy-rich syngas from the ...
Cellulosic sugars are used as renewable resources for biochemical and biofuels industries and can be used to produce intermediates by fermentative processes. The availability of industrial sugars from renewable resources, in sufficient quantities and at a favorable cost enables the products to be cost-competitive to fossil fuel based products.
Hemicellulose is located between and within the cellulose fibrils and is incorporated into the cellulose structure. The fiber or pulp with high hemicellulose content has a high maximum tensile strength and a low maximum tear index. The cellulosic fibers enclose the outside of cellulose fibers, acting as natural binders.