Cellulose production

Cellulosics. Rayon and other cellulose products such as cellophane and cellulose ethers (qv) consume 1.9% of U.S. caustic soda demand. Because of competitive products, however, this market has been decreasing since 1965 and forecasted average annual growth through 1992 is less than 0.4% (6) (see Cotton). 

A commercial bacterial cellulose product (CeUulon) was recently introduced by Weyerhaeuser (12). The fiber is produced by an aerobic fermentation of glucose from com symp in an agitated fermentor (13,14). Because of a small particle diameter (10 P-m), it has a surface area 300 times greater than normal wood cellulose, and gives a smooth mouthfeel to formulations in which it is included. CeUulon has an unusual level of water binding and works with other viscosity builders to improve their effectiveness. It is anticipated that it wiU achieve GRAS status, and is neutral in sensory quaUty microcrystaUine ceUulose has similar attributes. 

The major use of methyl chloride is to produce silicon polymers. Other uses include the synthesis of tetramethyl lead as a gasoline octane booster, a methylating agent in methyl cellulose production, a solvent, and a refrigerant. 

Uses Dielectric liquids in fixed paper capacitors heat-transfer liquid widely used in transformers and utility transmission lines swelling agents for transmission seals ingredient in lubricants, oils, and greases plasticizers for cellulose products, vinyl, and chlorinated rubbers in polyvinyl acetate to improve fiber-tear properties. In fluorescent and high-intensity discharge ballasts manufactured prior to 1979 (U.S. EPA, 1998) and in electric motors (Monsanto, 1960). 

Uses Manufacture of flavors and perfumes solvent for plastics, cellulose products, and resins lacquers, paints natural and synthetic resins lab reagent organic synthesis. 

The FP cellulose per unit (ml) volume and enzyme yield per unit (g) cellulose or substrate obtained on wheat straw, wood, and CTMP in SSF were higher than those obtained in LSF on wheat straw and wood (Tables I, II, and III). And wheat straw proved to be a better substrate than wood for cellulose production in SSF. This could be attributed to the polysaccharides (cellulose and hemicelluloses) of wheat straw being more readily available for the organism s growth and cellulose synthesis than those of wood. The hemicelluloses and cellulose were presumably not as available in wood, because of its high lignin content and high cellulose crystallinity, as in wheat straw. 

Azarniouch, M.K. and Thompson, K.M., "Alcohol from Cellulose-Production Technology", presented at "Alcohols as Alternative Fuels for Ontario" Symposium, Toronto, Ontario (19 Nov. 1976). Gaden, E.L., "Biotechnology - An Old Solution to a New Problem", Chem. Eng. Div. Award Lecture, Amer. Soc. Eng. Ed. National Meeting (June 1974). 

Azarniouch, M.K. and Thompson, K.M., Alcohols from Cellulose -Production Technology, presented at Symposium Canadian Society for Chemical Engineering and Canadian Society for Mechanical Engineering, Toronto, 1976. 

The most widely used inorganic ester of cellulose is cellulose nitrate (CN), also called nitrocellulose or gun cotton. Celluloid is produced from a mixture of CN and camphor. It was first made in 1833 when cellulose-containing linen, paper, or sawdust was reacted with concentrated nitric acid. It was the first synthetic cellulose product that was recognized. Initially, CN was used as a military explosive and improvements allowed the manufacture of smokeless powder. A representation of CN is given in structure 9.7. 

Regenerated proteins from casein (lanital), peanuts (ardil), soybeans (aralac), and zine (vicara) are used as specialty fibers. Regenerated and modified cellulose products, including acetate, are still widely used today and the production of fibers is similar to that described above for synthetic fiber production. Most regenerated cellulose (rayon) is produced by the viscose process where an aqueous solution of the sodium salt of cellulose xanthate is precipitated in an acid bath. The relatively weak fibers produced by this wet spinning process are stretched to produce strong rayon. 

Isolation and sequencing of the cellulose synthase gene(s) has not been accomplished yet however, DNA from Acetobacter xylinum containing this gene(s) was cloned into broad host-range plasmid vectors (82). These vectors were mobilized into Pel- mutants to test for complementation. To date, this approach has not produced a pellicle-forming transconjugant from a Pel- mutant of Acetobacter (82). The direct correlation between cellulose production and presence of plasmid DNA in Acetobacter has been reported... 

Ocular Effects. Workers employed at a sulfite-cellulose production facility reported ocular discomfort that was associated with periods when equipment failure resulted in relatively high air concentrations of chlorine dioxide (Gloemme and Lundgren 1957). However, this finding was confounded by concurrent exposure to chlorine gas and sulfur dioxide. 

Avicel RC and CL are water-dispersible, colloidal, microcrystalline cellulose products made for use in liquid preparations. Avicel RC and CL are coprocessed mixtures of microcrystalline cellulose and sodium carboxymethylcellulose. The amount of NaCMC can be determined using the IC method. About 10 g of Nasonex and about 25 mg of NaCMC NF are separately refluxed with 30 mL of glacial acetic acid for 2 h. The refluxed mixture is transferred to a 100-mL volumetric flask and diluted to volume with purified water, and mixed. The ion chromatograph (IC) was equipped with a suppressed conductivity detector, a 4-mm CSRS suppressor, current at 50 mA, a 250 mm x 4-mm Ion CS 12A column and a 50 mm x 4 mm Ion CG 12A guard column. The mobile phase is 0.13% methanesulfonic acid in water with a flow rate of 1 mL/min. Equal... 

American Cyanamid Company Process for producing cellulosic products. Brit. Pat. 884,805 (December 20, 1961). 

Some of the more recent SCP process concepts start with other materials, such as ethanol, acetic aad, staiches, sugars, and cellulosic products that may be more available and particularly so in the protein-needy developing countries. 

Rot and Weather Resistance. Cellulosic products are often used where degradation of the cellulose by microorganisms and by enzymes... 

The raw material that reaches the factory is a far cry from Avicel or Solka Floe that are used by many experimenters to simulate cellulosic products (Table I). In addition to the fact that the cellulose is tied up in a lignin-hemicellulose-cellulose (LHC) complex, it should be recognized that the terms lignin and hemicellulose are catchall terms covering a range of compositions and molecular weights. 

Cellulosic wastes have great potential as a feedstock for producing fuels and chemicals. Cellulose is a renewable resource that is inexpensive, widely available and present in ample quantities. Large amounts of waste cellulose products are generated by commercial and agricultural processes. In addition, municipal facilities must treat or dispose of tremendous quantities of cellulosic solid waste. 

The use of membranes for separating particles of colloidal dimensions is termed dialysis. The most commonly used membranes are prepared from regenerated cellulose products such as collodion (a partially evaporated solution of cellulose nitrate in alcohol plus ether), Cellophane and Visking. Membranes with various, approximately known, pore sizes can be obtained commercially (usually in the form of sausage skins or thimbles ). However, particle size and pore size cannot be properly correlated, since the permeability of a membrane is also affected by factors such as electrical repulsion when. the membrane and particles are of like charge, and particle adsorption on the filter which can lead to a blocking of the pores. 

Other compounds that we should consider are those derived from ligno-cellulose. Production of LMW components during oxidation of lignin, a biopolymer found only in terrestrial plants, may be quite high in fresh-waters where the input of ligno-cellulose and other allochthonous DOM is substantial (see Chapter 2). But we know little about LMW byproducts from ligno-cellulose degradation (Benner and Hodson, 1985 Moran and Hodson, 1989). 

Gluconacetobacter xylinus to optimize cellulose formation on the laboratory-scale [12]. As a result of systematic and comprehensive research over the last 10-15 years, broad knowledge of the formation and structure of BC has been acquired. This work is an important part of the integration of biotechnological methods into polysaccharide chemistry and the development of cellulose products with new properties and application potential. 

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