Resources renewable

Polysaccharides are macromolecules which make up a large part of the bulk of the vegetable kingdom. Cellulose and starch are, respectively, the first and second most abundant organic compounds in plants. The former is present in leaves and grasses the latter in fruits, stems, and roots. Because of their abundance in nature and because of contemporary interest in renewable resources, there is a great deal of interest in these compounds. Both cellulose and starch are hydrolyzed by acids to D-glucose, the repeat unit in both polymer chains. 

Triglyceride oils have declined since the 1980s and have been replaced by petroleum-derived products. However, as fossil fuels deplete the supply of petrochemicals, triglyceride-based oils are available as a renewable resource. 

Because oil and gas ate not renewable resources, at some point in time alternative feedstocks will become attractive however, this point appears to be fat in the future. Of the alternatives, only biomass is a renewable resource (see Fuels frombiomass). The only chemical produced from biomass in commercial quantities at the present time is ethanol by fermentation. The cost of ethanol from biomass is not yet competitive with synthetically produced ethanol from ethylene. Ethanol (qv) can be converted into a number of petrochemical derivatives and could become a significant source. 

Other sources of energy worth noting are the extensive wind farms, solar projects, and related emerging unconventional technologies. These renewable resources provide only small quantities of energy to the U.S. economy as of this writing. 

Advances in technology have increased the importance of lignin products in various industrial appHcations. They are derived from an abundant, renewable resource, and they are nontoxic and versatile in performance. 

Polyesters are known to be produced by many bacteria as intracellular reserve materials for use as a food source during periods of environmental stress. They have received a great deal of attention since the 1970s because they are biodegradable, can be processed as plastic materials, are produced from renewable resources, and can be produced by many bacteria in a range of compositions. The thermoplastic polymers have properties that vary from soft elastomers to rigid brittie plastics in accordance with the stmcture of the pendent side-chain of the polyester. The general stmcture of this class of compounds is shown by (3), where R = CH3, n = >100, and m = 0-8. 

Paper (qv) is a material of tremendous versatility and utility, prepared from a renewable resource. It may be made soft or stiff, dense or porous, absorbent or water repellent, textured or smooth. Some of the versatility originates with the fibers, which may vary from short and supple to long and stiff, but the contribution of chemicals should not be underestimated (see Papermaking materials and additives). 

Chemurgy is defined as that branch of appHed chemistry devoted to industrial utilization of organic raw materials, especially from farm products. A more modem and general definition for chemurgy is the use of renewable resources particularly biomass, usually plant or microbial material, for materials and energy (see Fuels frombiomass Fuels fromwaste). 

Increasingly, biochemical transformations are used to modify renewable resources into useful materials (see Microbial transformations). Fermentation (qv) to ethanol is the oldest of such conversions. Another example is the ceU-free enzyme catalyzed isomerization of glucose to fmctose for use as sweeteners (qv). The enzymatic hydrolysis of cellulose is a biochemical competitor for the acid catalyzed reaction. 

A rather impressive Hst of materials and products are made from renewable resources. For example, per capita consumption of wood is twice that of all metals combined. The ceUulosic fibers, rayon and cellulose acetate, are among the oldest and stiU relatively popular textile fibers and plastics. Soy and other oilseeds, including the cereals, are refined into important commodities such as starch, protein, oil, and their derivatives. The naval stores, turpentine, pine oil, and resin, are stiU important although their sources are changing from the traditional gum and pine stumps to tall oil recovered from pulping. 

National Research Council, Renewable Resources for Industrial Materials, National Academy of Sciences, Washington, D.C., 1976. 

Ethylene. Where ethylene is ia short supply and fermentation ethanol is made economically feasible, such as ia India and Bra2il, ethylene is manufactured by the vapor-phase dehydration of ethanol. The production of ethylene [74-85-1] from ethanol usiag naturally renewable resources is an active and useful alternative to the pyrolysis process based on nonrenewable petroleum. This route may make ethanol a significant raw material source for produciag other chemicals. 

George T. Tsao, Ph.D., Director, Laboratory for Renewable Resource Engineering, Purdue University Member, American Institute of Chemical Engineers, American Chemical Society, American Society for Microbiology (Section 24, Biochemical Engineering)... 

NOVEL MATERIALS FOR CATALYSIS AND ANALYSIS DERIVED FROM RENEWABLE RESOURCES... 

Pulp and paper manufacture is increasing in the world at an exponential rate. The demand for paper will continue as new uses are found for this product. Since most paper is manufactured from wood or wood residue, it provides an excellent use for this renewable resource. 

The agricultural and forest products industries are dependent on renewable resources for their existence. They are also acutely aware that air pollution can damage vegetation and, therefore, threaten their existence. Both industries have been exempt from many air pollution regulations in the past, but now they are finding these exemptions questioned and in some cases withdrawn (15). 

We have expanded some subject areas, which previously were of concern to only a few scientists, but which have been popularized by the media to the point where they are common discussion subjects. These include "Global Warming," "The Ozone Hole," "Energy Conservation," "Renewable Resources," and "Quality of Life."... 

Numerous other polyols are commercially available, some from renewable resources. Urethanes based on castor oil have been used for many years as encapsulants for electronic components, due to their hydrophobic nature [29J. 

C. E. Carraher, Jr. and C. H. Sperling (eds.), Polymer Applications of Renewable Resource Materials, Plenum Press, New York and London (1981). 

Biodiesel is diesel fuel produced from vegetable oils and other renewable resources. Many different types of oils can he used, including animal fats, used cooking oils, and soybean oil. Biodiesel is miscible with petroleum diesels and can he used in biodiesel-diesel blends. Most often blends are 20 percent biodiesel and 80 percent traditional diesel. Soy diesel can be used neat (100%), hut many other types of biodiesel are too viscous, especially in winter, and must be used in blends to remain fluid. The properties of the fuel will vaiy depending on the raw material used. Typical values for biodiesel are shown in Table 1. 

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