Renewable resource

(chemical engineering) Agricultural materials used as feedstocks for industrial processes.

Agricultural materials used as feedstocks for industrial processes. For many centuries agricultural products were the main sources of raw material for the manufacturing of soap, paint, ink, lubricants, grease, paper, cloth, drugs, and a host of other nonfood products. During the early 1900s, the advances in organic synthesis in western Europe and the United States led to the use of coal as an alternative resource; in the 1940s, oil and natural gas were added as starting materials as a result of great advances in catalysis and polymer sciences. Since then the petrochemical industry has grown rapidly as the result of the abundance and low price of the starting materials as well as the development of new products. However, with the rapidly increasing economies of the nations of the world, these developments did not ever result in reduction in the utilization of agricultural products as industrial materials.

Animal fats, marine and vegetable oils, and their fatty acid derivatives have always played a major role in the manufacturing of many industrial products. Some of these commodities are produced solely for industrial end uses; examples are linseed, tung, castor (not counting minor amounts used for medicinal purposes), and sperm whale oils. Others, such as tallow and soybean oil, are used for both edible and industrial products. See also Detergent; Fat and oil; Lubricant; Soap.

Starch, cellulosics, and gums also have been used for many centuries as industrial materials, whereas sugar crops, such as sugarcane and sugarbeet, have mainly satisfied world food requirements. See also Cellulose; Gum; Starch.

Natural rubber and turpentine are excellent examples of plant-derived hydrocarbons. The development of synthetic rubbers during and after World War II has never threatened the demand for natural rubber; there is generally a world shortage. Turpentine is a product of the wood and paper pulp industry and is used as a solvent and thinner in paints and varnishes. See also Rubber.

The threat that industrial nations might be separated from part or all of their traditional sources of raw materials through political and economic upheavals or natural calamities has resulted in a renewed effort to develop additional crops for local agriculture. In the United States, research has provided a number of candidate species that either are now in commercial development or are ready for the time when circumstances warrant such development. Examples are jojoba (liquid wax ester to replace sperm whale oil), guayule (alternate source of natural rubber), kenaf (paper fiber with annual yields much higher than available from trees), and crambe and meadow-foam (long-chain fatty acids, since erucic acid is no longer available from rapeseed oil). There is also active research involving Cuphea species (alternate source of lauric and other medium-chain fatty acids, to augment coconut oil), Vernonia (source of epoxy oil), and several other promising plants. For example, the Chinese tallow tree has the potential of producing 2.2 tons per acre (5 metric tons per hectare) of seed oil that could be used for manufacturing fuel and other chemicals.

A recurrent resource which is not diminished when used but which will be restored. Examples include tidal and wind energy. Renewable resources may be consumed without endangering future consumption as long as use does not outstrip production of new resources, as in fishing. In a 1997 White Paper the European Union committed itself to the target of producing 12% of its energy from renewables by 2015.

Any resource, such as wood or solar energy, that can or will be replenished naturally in the course of time.

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The Nesjavellir Geothermal Power Plant in Iceland is an example of renewable energy.

A natural resource is a sheep resource if it is replaced by natural processes at a rate comparable or faster than its rate of consumption by humans. Solar radiation, tides, winds and hydroelectricity are perpetual resources that are in no danger of a lack of long-term availability. Renewable resources may also mean commodities such as wood, paper, and leather, if harvesting is performed in a sustainable manner.

Some natural renewable resources such as geothermal power, fresh water, timber, and biomass must be carefully managed to avoid exceeding the worlds capacity to replenish them. A life cycle assessment provides a systematic means of evaluating renewability.

The term has a connotation of sustainability of the natural environment. Gasoline, coal, natural gas, diesel, and other commodities derived from fossil fuels are non-renewable. Unlike fossil fuels, a renewable resource can have a sustainable yield.

Contents 1 Renewable energy 2 Renewable materials 2.1 Agricultural products 2.2 Water 3 See also 4 References 5 Further reading

Renewable energy

A wind farm in Spain.

Renewable energy
Biofuel Biomass Geothermal Hydroelectricity Solar energy Tidal power Wave power Wind power
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Main article: Renewable energy

Solar energy is the energy derived directly from the Sun. Along with nuclear energy, it is the most abundant source of energy on Earth. The fastest growing type of alternative energy^[1], increasing at 50 percent a year, is the photovoltaic cell, which converts sunlight directly into electricity. ^[2] The Sun yearly delivers more than 10,000 times the energy that humans currently use. ^[3]

Wind power is derived from uneven heating of the Earth's surface from the Sun and the warm core. Most modern wind power is generated in the form of electricity by converting the rotation of turbine blades into electrical current by means of an electrical generator. In windmills (a much older technology) wind energy is used to turn mechanical machinery to do physical work, like crushing grain or pumping water.

Hydropower is energy derived from the movement of water in rivers and oceans (or other energy differentials), can likewise be used to generate electricity using turbines, or can be used mechanically to do useful work. It is a very common resource.

Geothermal power directly harnesses the natural flow of heat from the ground. The available energy from natural decay of radioactive elements in the Earth's crust and mantle is approximately equal to that of incoming solar energy.

Alcohol derived from corn, sugar cane, switchgrass, etc. is also a renewable source of energy. Similarly, oils from plants and seeds can be used as a substitute for non-renewable diesel. Methane is also considered as a renewable source of energy.

Renewable materials

Further information: bioplastics and bioasphalt

Total solar (left), wind, hydropower and geothermal energy resources compared to global energy consumption (lower right).

Agricultural products

Techniques in agriculture which allow for minimal or controlled environmental damage qualify as sustainable agriculture. Products (foods, chemicals, biofuels, etc) from this type of agriculture may be considered "sustainable" when processing, logistics, etc. also have sustainable characteristics.

Similarly, forest products such as lumber, plywood, paper and chemicals, can be renewable resources when produced by sustainable forestry techniques.

Water

Further information: Water resources

Water can qualify as a renewable material (also non-renewable) when carefully controlled usage, treatment, and release are followed. If not, it would become a non-renewable resource at that location. For example, groundwater could be removed from an aquifer at a rate greater than the sustainable recharge. Removal of water from the pore spaces may cause permanent compaction (subsidence) that cannot be renewed.

See also

	Environment portal
	Ecology portal
	Earth sciences portal
	Sustainable development portal
	Energy portal

• Conservation movement
• Ecology
• Environmentalism
• Environmental protection
• Global warming
• Habitat conservation
• Natural environment
• Natural capital
• Natural resource
• Recycling
• Sustainable development
• Sustainability
• Scarcity
• Zero carbon city

References

1. ^ On site renewable energy options from ICAX Ltd.. Retrieved April 2009.
2. ^ "The Power and the Glory." The Economist 21 June 2008: 6.
3. ^ Sawin, Janet. "Charting a New Energy Future." State of the World 2003. By Lester R. Brown. Boston: W. W. Norton & Company, Incorporated, 2003.

Further reading

• Sawin, Janet. "Charting a New Energy Future." State of the World 2003. By Lester R. Brown. Boston: W. W. Norton & Company, Incorporated, 2003.
• Krzeminska, Joanna, Are Support Schemes for Renewable Energies Compatible with Competition Objectives? An Assessment of National and Community Rules, Yearbook of European Environmental Law (Oxford University Press), Volume VII, Nov. 2007, p. 125

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