Cellulose solid fuel

Uses Manufacture of nylon solvent for cellulose ethers, fats, oils, waxes, resins, bitumens, crude rubber paint and varnish removers extracting essential oils glass substitutes solid fuels fungicides gasoline and coal tar component organic synthesis. 

Complex pyrolysis chemistry takes place in the conversion system of any conventional solid-fuel combustion system. The pyrolytic properties of biomass are controlled by the chemical composition of its major components, namely cellulose, hemicellulose, and lignin. Pyrolysis of these biopolymers proceeds through a series of complex, concurrent and consecutive reactions and provides a variety of products which can be divided into char, volatile (non-condensible) organic compounds (VOC), condensible organic compounds (tar), and permanent gases (water vapour, nitrogen oxides, carbon dioxide). The pyrolysis products should finally be completely oxidised in the combustion system (Figure 14). Emission problems arise as a consequence of bad control over the combustion system. 

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 former variables affect the deposition of heat in the solid fuel and its transient temperature-profile, as well as the diffusion of the volatile pyrolysis products and their distribution and mixing with the surrounding atmosphere. The latter factors influence the nature and sequence of the primary and secondary reactions involved, the composition of the flammable volatiles, and, ultimately, the kinetics of the combustion. Consequently, basic study of the combustion of cellulosic materials or fire research has been channeled in these two directions. 

After the war Hercules returned to the production of commercial explosives as well as military propellants and continued to build on its cellulose and naval stores capabilities. In 1958 its explosives department created a chemical propulsion division to develop propellants for missiles and space vehicles. In 1959 it received contracts from the U.S. Air Force to develop new solid-fuel rocket motors and subsequently produced the motor for the third stage of the nation s first solid-fuel intercontinental ballistic missile (ICBM), the Minuteman. Hercules played an even larger role in the development of the Navy s submarine-launched Polaris ICBM. With cellulose came new specialties, including synthetic resins and paper chemicals, as well as carboxymethylcellulose (CMC), an intermediate used in the production of foods, pharmaceuticals, and cosmetics. From naval stores came other new specialty chemicals and an effective insecticide, toxaphene, and other agricultural chemicals.3... 

While many cellulosic wastes, particularly wood, can be and are being converted to secondary solid fuels (see above and Section 6.10.2) efforts are also undertaken to produce agglomerated, value-added secondary raw material that can be used in the manufacturing of engineered wood products. One such method is described in Swiss patent SP 530 261 [Section 13.3]. It shows that saw dust, which is produced in large... 

Uses Solvent for cellulose ethers, fats, oils, waxes, inks, lacquers, resins, coatings paint and varnish remover extraction solvent for essential oils glass substitutes laboratory reagent chemical intermediate in fungicidal formulations mfg. of nylon, adipic acid, benzene, cyclohexanone, etc. mfg. of solid fuel for camp stoves diluent in food colorants solvent in cosmetics, pharmaceutical orals in food-pkg. adhesives defoamer in food-contact paper coatings... 

Many cellulose esters have been developed. They include acetates, acetopropionates, acetobutyrates and nitrates. As the crystallinity of cellulose is suppressed by such substitutions, the esters are thermoplastic and can be manufactured by usual methods, e.g. extrusion or moulding. Properties of these compounds depend on the type of substituent and on the degree of substitution. Cellulose nitrates were the first modified polymers. Depending on the degree of substitution, different applications have been developed Highly nitrated cellulose is a well-known explosive, whereas a little less substituted cellulose is used as solid fuel for rockets and the least substituted cellulose is a thermoplastic called celluloid. Celluloid was used to make films for early movies and moulded objects, e.g. dolls and table tennis balls. However, as celluloid is highly flammable, other esters have almost completely replaced cellulose nitrates for manufacturing everyday objects. 

The majority of solids will undergo a chemical decomposition, better known as pyrolysis. Pyrolysis is the chemical decomposition of the solid fuel by the apphcation of a heat source. As the molecular bonds begin to break down, smaller molecules (lower molecular weights) are released in the gaseous form and ignited if released from the solid at a sufficient rate that the flammable limit is reached. Most solids will undergo this process of pyrolysis when exposed to a sufficient heat source some, however, may melt first and vaporize like a liquid. For example, cellulosic materials (i.e., wood, paper) and thermoset polymers will undergo pyrolysis and leave behind a carbonaceous residue (char) in the presence of a sufficient heat source, but thermoplastics (plastic bottles) will melt when exposed to heat and vaporize similar to liquids. 

The hemicellulose and cellulose polymers are hydrolyzed with enz5unes Cellulases or Hemicellulases to release monomeric sugars. The sugars from the pretreatment and enzymahc hydrolysis steps are fermented by bacteria, yeast, or filamentous fungi, although enzymatic hydrolysis and fermentation can also be performed in a combined step called simultaneous saccharification and fermentation. After a final purification (by distillation and molecular sieves), the ethanol is ready to be used as a fuel, either neat or blended with petrol. A part of the lignin (remaining biomass) can be burned to provide heat and electricity for the process, whereas the rest is retained as a valuable coproduct. The most probable use today would be as an ash-free solid fuel (Fernando et al., 2006). 

Both in the USA and the EU, the introduction of renewable fuels standards is likely to increase considerably the consumption of bioethanol. Lignocelluloses from agricultural and forest industry residues and/or the carbohydrate fraction of municipal solid waste (MSW) will be the future source of biomass, but starch-rich sources such as corn grain (the major raw material for ethanol in USA) and sugar cane (in Brazil) are currently used. Although land devoted to fuel could reduce land available for food production, this is at present not a serious problem, but could become progressively more important with increasing use of bioethanol. For this reason, it is important to utilize other crops that could be cultivated in unused land (an important social factor to preserve rural populations) and, especially, start to use cellulose-based feedstocks and waste materials as raw material. 

Solid wood material is built up of two major organic polymers (macro molecules) (1) polysaccharides and (2) polyphenylpropane [61,62], The polysaccharides consist of two groups - cellulose and hemicellulose, and make up around 65-75 % of the wood on dry basis. The polyphenylpropanes are more commonly termed lignins and constitute around 18-35 % of the wood on dry basis. In Table 9 we can see that wood fuels consist of extractives, minerals, and nitrogen as well. The chemical composition of wood of Sweden s most commonly wood species [63], the spruce, the pine and the birch are different, see Table 9. 

This paper is concerned with the potential for production of liquid fuels from biomass in Canada. To this end, the availability and cost of wood wastes, surplus roundwood, bush residues, energy plantation trees, and municipal solid wastes (mostly cellulosic) are assessed and promising thermal, chemical and biochemical conversion processes reviewed. 

Ethanol can also be produced from cellulose (qv) or biomass such as wood (qv), com stover, and municipal solid wastes (see Fuels frombiomass Fuels FROMWASTE). Each of these resources has inherent technical or economic problems. The Tennessee Valley Authority (TVA) is operating a 2 t/d pilot plant on converting cellulose to ethanol. 

Cell-Pitch Lye, It is a solid combustible material produced by evapn of spent waste liquid obtained from fermentation of sulfite-cellulose waste lyes(Ref 1). Was used in Germany as a fuel, as a binding agent and as an ingredient of AN explosives(Ref 2)... 

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