Renewable resources sources

Several issues remain to be resolved. For one, it is not typically cost effective for large-scale production from renewable resources. Sourcing is a concern, and it is unclear whether there are sufficient biomass resources available to meet societal demands. The intermittency of biomass availability is also an issue. All of these aspects need to be considered in the evaluation of what may ultimately become the major source of chemicals and energy for the future. 

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. 

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. 

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. 

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. 

C. E. Carraher, Jr. and L. H. Sperling (eds.). Renewable Resource Materials New Polymer Sources, Plenum Press, New York (1985). 

Methane from renewable biological sources will never be a major energy resource, yet it can be a valuable addition to the energy supply mix. Nevertheless, whether methane comes from fossil fuel reservoirs or from bioconversions, it is certain to provide useful energy for many years to come. 

As will be evident from the above discussion many valuable chemicals can be made from renewable resources. In many cases current production methods fail to compete effectively with routes from fossil sources. With advances in biotechnology and increasing oil prices, renewable feedstocks will become more commercially attractive, especially for fine, speciality and pharmaceutical chemicals. If future bulk chemical production were to... 

Mineral resources are nonrenewable resources, in contrast to renewable resources such as surface water and timber, which are or can be replenished naturally or artificially. The geological processes by which most mineral deposits form take a very long time. They can, in no way, be thought to replenish deposits extracted from the ground and dispersed by use. However, it is important to recognize that mineral resources are extendable with the help of advancing technology that develops uses for sources that were not readily usable or exploitable before, allows hidden deposits to be discovered, and enhances the efficiency of recovery and of use. 

J.J. Meister, Review of the Synthesis, Characterization, and Testing of Graft Copolymers of Lignin, p.305-322 of Renewable-Resource Materials New Polymer Sources, C.E. Carraher,... 

In conclusion, it is noteworthy that cyclodextrins, liposomes and chitin derivatives are all readily available from renewable biochemical sources and offer advantages of biodegradability and safety in use. However, it needs to be borne in mind that this fact alone does not necessarily mean that they are entirely environmentally innocuous in the long run. Demands on resources for the husbanding and processing of bioforms that may be necessary in order to sustain demand for commercially viable qualities and quantities can exert deleterious effects, not least because they may give by-products that present problems of utilisation or disposal [70]. 

Demirbas, M. F., Technological options for producing hydrogen from renewable resources. Energy Sources, Part A Recovery, Utilization, and Environmental Effects 2006, 28(13), 1215-1223. 

McKinley, K.R., Browne, S.H., Neill, D.R., Seki, A., and Taka-hashi, PK. (1990). Hydrogen Fuel from Renewable Resources, Energy Sources, 12. pp. 105-110. 

The Non-renewable Resource Assessments (NRAs) are part of step 5 in an 8-step process that may ultimately result in (partial or limited) protection of certain areas from development. Phase 1 of an NRA is a desktop exercise that evaluates all existing mineral deposit and survey data for an area from all sources, determines knowledge gaps of the mineral potential, and suggests an approach for Phase 2 follow-up work. Phase 2 of the NRA typically involves field and analytical work designed to lead to a better understanding of the resource potential for a candidate protected area. 

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