Materials nonrenewable sources

Although timber production and utilization can result in substantial environmental benefits compared with materials extracted from nonrenewable sources, timber utilization and forestry have become associated with negative environmental impacts. Tropical deforestation... 

Figure 13.4b emphasizes the finite nature and strong irreversibility of an economic system. The stock of energy and resources will eventually run out and so will the absorptive capacity of the environment for waste. An obvious extension of Figure 13.4b, therefore, is the one represented by Figure 13.4c. Just like in nature, waste has to be recycled. In nature, there is no real waste. Every form of waste is a resource for a living system. This living system is very small and called a microbe. Microbes make sure that all matter recycles in nature. Man needs to assume this humble but valuable and important role of microbes in the economic system and make sure that the material cycles get closed. Therefore, energy (or rather work) is required. But obviously this work should not be supplied from a nonrenewable source, like fossil fuels, but rather from a renewable source like the sun. Figure 13.4c therefore seems to be characteristic for a sustainable economic system and agrees remarkably with the definition of sustainability from biological systems A...

This chapter has shown how it is possible to produce materials that will allow us to continue enjoying the benefits of the present in a future that will have to provide them with less and less reliance on nonrenewable sources of energy. The answer will come partly from the rarer metals of this planet, although one of those may well be the limiting factor to all that we might achieve, and that metal is indium. 

The replacement of petroleum-derived (nonrenewable) sources of adhesive raw materials with renewable sources will follow three basic strategies 1) renewable materials will be used to replace part of the required petroleum-derived adhesive systems, 2) new polymeric adhesives will be synthesized from renewable materials and totally replace petroleum-derived adhesive systems, or 3) the adhesives systems now based on petroleum-derived materials will continue to be used, but the adhesive raw materials will be derived from renewable sources instead of from nonrenewable ones. Carbohydrates are very versatile chemicals that can be utilized in all three strategies as demonstrated by the preceding discussion. 

Although hydrogen allows tremendous choices for anode materials and provides good results, the production of hydrogen from nonrenewable sources is still far from being competitive economically. Therefore the sustainable hydrogen from water seems to be a better choice. However, the use of water instead of H2 requires an excellent electrocatalyst. The electrolysis reaction to attain protons at the anode in a PCMR is ... 

The expanding interest in alternative surfactants made from renewable resources has been driven somewhat by the perceived environmental benefits that these materials have over those from nonrenewable sources. While it is true that these aspects have been a significant driver in the level of interest in carbohydrate-based surfactants in particular, the unique physicochemical properties of these materials offer significant advantages over other materials in some applications. 

Wood is the raw material of the naval stores iadustry (77). Naval stores, so named because of their importance to the wooden ships of past centuries, consist of rosin (diterpene resin acids), turpentine (monoterpene hydrocarbons), and associated chemicals derived from pine (see Terpenoids). These were obtained by wounding the tree to yield pine gum, but the high labor costs have substantially reduced this production in the United States. Another source of rosin and turpentine is through extraction of old pine stumps, but this is a nonrenewable resource and this iadustry is in decline. The most important source of naval stores is spent sulfate pulpiag Hquors from kraft pulpiag of pine. In 1995, U.S. production of rosin from all sources was estimated at under 300,000 metric tons and of turpentine at 70,000 metric tons. Distillation of tall oil provides, in addition to rosin, nearly 128,000 metric tons of tall oil fatty acids annually (78). 

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. 

It is clear that the use (incidental or otherwise) of toxic chemicals has impacts in different spheres of human existence such as state structures and infrastructure, economics, psychic and public behavior, and the environment. Toxic chemicals are a great consumer of natural sources, both renewable and nonrenewable. They also consume raw materials and energy, and as a consequence... 

About 70% of materials that are routinely disposed of in landfills could be recycled instead. More than 30% of bulk municipal garbage collections consist of paper that could be remanufactured into other paper products. Other materials like plastic, metal, and glass can also be reused in manufacturing, which can greatly reduce the amount of waste materials disposed in landfills, as well as preserving sources of nonrenewable raw materials. 

For at least the first half of the 21st century the world will continue to rely heavily on petroleum and coal as fuels and as hydrocarbon sources for use in making polymers, etc. Improved versions of existing catalysts, as well as new catalysts/processes, will be vital in making an orderly transition from reliance on nonrenewable resources. Included in this will be the continued development of practicable fuel cell technology and processes for synthesizing clean fuels from coal, tar sands, etc. Catalysis will play a role in the shift toward increased use of renewable/recycled materials and in efforts to minimize air pollution. Catalysts that mimic... 

For a sustainable future, more things will have to be made from renewable resources and fewer from nonrenewable resources. This means using paper instead of plastic wherever possible, unless the plastic is based on a renewable source (as described in Chap. 12). The throwaway habit must be thrown away in favor of reusable objects, designed for long life, easy repair, and ease of recycling of the materials in them. Objects made of 100% postcon sumer waste must become common, instead of being rare as they are today. 

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