Carbon dioxide fossil fuel

As pollutants go, carbon dioxide might be considered a relatively innocuous component of our atmosphere. After all, every breath we exhale contains about 4% carbon dioxide even though the inhaled air is only about 0.04% carbon dioxide. Fossil fuel combustion and natural decay processes combined with forest and grassland fires release billions of metric tons of carbon dioxide into the atmosphere annually. At the same time, trees, grasses, and other plants remove equivalent quantities of carbon dioxide from our atmosphere each year. Carbon dioxide is constantly being dissolved in and released from the ocean and other bodies of water as their temperature fluctuates. In other words, carbon dioxide is constantly being added to and removed from our atmosphere by a variety of processes, some natural and some of human origin. 

Despite the fact that they are chemically identical, it is possible to analytically identify bio-based plastics apart from identical fossil fuel-based plastics. Carbon dioxide in air has two isotopic forms of carbon, CO and CO, in equilibrium with each other, and plastics derived from plant sources will therefore have both these isotopes. Any isotopic carbon in fossil fuel deposits, however, had long decayed over the millions of years since their formation (half-life of C is 5730 years) into C and fossil fuels, and plastics made from them do not have significant levels of Burning a sample of plastic and measuring the ratio in the CO using liquid scintillation counting or isotope-ratio mass spectrometry therefore provide a test as to the origin of the plastic (ASTM D 6866). 

Significant costs, both economic and environmental, have been identified in the use of fossil fuels for the production of electricity. Economically, the prices of fossil fuels have been driven upward by the market economy, and environmentally, the combustion of large quantities of carbon-based fossil fuels releases a great deal of carbon dioxide and other gases into the atmosphere. 

Burning of any hydrocarbon (fossil fuel) or, for that matter, any organic material converts its carbon content to carbon dioxide and its hydrogen to water. Because power plants and other industries emit large amounts of carbon dioxide, they contribute to the so-called greenhouse warming effect on our planet, which causes significant en-... 

The control of carbon dioxide emission from burning fossil fuels in power plants or other industries has been suggested as being possible with different methods, of which sequestration (i.e., collecting CO2 and injecting it to the depth of the seas) has been much talked about recently. Besides of the obvious cost and technical difficulties, this would only store, not dispose of, CO2 (although natural processes in the seas eventually can form carbonates, albeit only over very long periods of time). 

In photosynthesis, nature recycles carbon dioxide and water, using the energy of sunlight, into carbohydrates and thus new plant life. The subsequent formation of fossil fuels from the biomass, however, takes... 

Rayon is unique among the mass produced man-made fibers because it is the only one to use a natural polymer (cellulose) directly. Polyesters, nylons, polyolefins, and acryflcs all come indirectly from vegetation they come from the polymerization of monomers obtained from reserves of fossil fuels, which in turn were formed by the incomplete biodegradation of vegetation that grew millions of years ago. The extraction of these nonrenewable reserves and the resulting return to the atmosphere of the carbon dioxide from which they were made is one of the most important environmental issues of current times. CeUulosic fibers therefore have much to recommend them provided that the processes used to make them have minimal environmental impact. 

Vinyl compares favorably to other packaging materials. In 1992, a lifecycle assessment comparison of specific packages made from glass, paperboard, paper, and selected plastics concluded that vinyl was the material that has the lowest production energy and carbon dioxide emissions, as well as the lowest fossil fuel and raw material requirements of the plastics studied (169). Vinyl saves more than 34 million Btu per 1000 pounds manufactured compared to the highest energy-consuming plastic (170). 

Furthermore, it is not tme that other plastics are more environmentally friendly than vinyl. A more recent study compared vinyl to a number of other packaging materials and found that vinyl consumed the least amount of energy, used the lowest level of fossil fuels, consumed the least amount of raw materials, and produced the lowest levels of carbon dioxide of any of the plastics studied (184). In fact, the Norwegian environmental group BeUona has concluded that a generally reduced use of vinyl plastics can lead to a worsening of the environmental situation (185). 

Carbon. Most of the Earth s supply of carbon is stored in carbonate rocks in the Hthosphere. Normally the circulation rate for Hthospheric carbon is slow compared with that of carbon between the atmosphere and biosphere. The carbon cycle has received much attention in recent years as a result of research into the possible relation between increased atmospheric carbon dioxide concentration, most of which is produced by combustion of fossil fuel, and the "greenhouse effect," or global warming. Extensive research has been done on the rate at which carbon dioxide might be converted to cellulose and other photosyntheticaHy produced organic compounds by various forms of natural and cultivated plants. Estimates also have been made of the rate at which carbon dioxide is released to soil under optimum conditions by various kinds of plant cover, such as temperature-zone deciduous forests, cultivated farm crops, prairie grassland, and desert vegetation. 

The balance between animal and plant life cycles as affected by the solubiHty of carbon dioxide ia the earth s water results ia the carbon dioxide content ia the atmosphere of about 0.03 vol %. However, carbon dioxide content of the atmosphere seems to be increa sing as iacreased amounts of fossil fuels are burned. There is some evidence that the rate of release of carbon dioxide to the atmosphere may be greater than the earth s abiHty to assimilate it. Measurements from the U.S. Water Bureau show an iacrease of 1.36% ia the CO2 content of the atmosphere ia a five-year period and predictions iadicate that by the year 2000 the content may have iacreased by 25% (see Airpollution). 

The increasing number of atomic reactors used for power generation has been questioned from several environmental points of view. A modern atomic plant, as shown in Fig. 28-3, appears to be relatively pollution free compared to the more familiar fossil fuel-fired plant, which emits carbon monoxide and carbon dioxide, oxides of nitrogen and sulfur, hydrocarbons, and fly ash. However, waste and spent-fuel disposal problems may offset the apparent advantages. These problems (along with steam generator leaks) caused the plant shown in Fig. 28-3 to close permanently in 199T. 

Combustion processes are the most important source of air pollutants. Normal products of complete combustion of fossil fuel, e.g. coal, oil or natural gas, are carbon dioxide, water vapour and nitrogen. However, traces of sulphur and incomplete combustion result in emissions of carbon monoxide, sulphur oxides, oxides of nitrogen, unburned hydrocarbons and particulates. These are primary pollutants . Some may take part in reactions in the atmosphere producing secondary pollutants , e.g. photochemical smogs and acid mists. Escaping gas, or vapour, may... 

One of the main benefits from future use of biofuels would be the reduction of greenhouse gases compared to the use of fossil fuels. Carbon dioxide, a greenhouse gas that contributes to global warming, is released into the air from combustion. Twenty-four percent of worldwide energy-related carbon emissions in 1997 were from the United States. Carbon... 

To comply with carbon reduction goals, some countries impose taxes on carbon dioxide emissions. Since biofuels have lower full-cycle carbon dioxide emissions than fossil fuels, biofuels are more cost-competitive with fossil fuels in regions where these taxes are imposed. 

Burning fossil fuels can release air pollutants such as carbon dioxide, sulfur oxides, nitrogen oxides, ozone, and particulate matter. Sulfur and nitrogen oxides contribute to acid rain ozone is a component of urban smog, and particulate matter affects respiratory health. In fact, several studies have documented a disturbing correlation between suspended particulate levels and human mortality. It is estimated that air pollution may help cause 500,000 premature deaths and millions of new respiratory illnesses each year. 

---