Fossil fuels description

Acid rain is the popular term for a very complex environmental problem. Over the past 25 years, evidence has accumulated on changes in aquatic life and soil pH in Scandinavia, Canada, and the northeastern United States. Many believe that these changes are caused by acidic deposition traceable to pollutant acid precursors that result from the burning of fossil fuels. Acid rain is only one component of acidic deposition, a more appropriate description of this phenomenon. Acidic deposition is the combined total of wet and dry deposition, with wet acidic deposition being commonly referred to as acid rain. 

Nowhere is the effect of anthropogenic stress felt more than in the development of natural resources of the Earth. Natural resources are varied in nature and often require definition. Eor example, in relation to mineral resources, for which there is also descriptive nomenclature (ASTM C294), the terms related to the available quantities of the resource must be defined. In this instance, the term resource refers to the total amount of the mineral that has been estimated to be available ultimately. The term reserves refers to well-identified resources that can profitably be extracted and utilized by means of existing technology. In many countries, fossil fuel resources are often classified as a subgroup of the total mineral resources. 

Petroleum is a resource, in particular, petroleum is a fossil fuel resource (Speight, 1999). A resource is the entire commodity that exists in the sediments and strata whereas the reserves represent that fraction of a commodity that can be recovered economically. However, the use of the term reserves as being descriptive of the resource is subject to much speculation. In fact, it is subject to word variations For example, reserves are classed as proved, unproved, probable, possible, and undiscovered. 

Figure 15.19 gives a description of the global carbon cycle. The inventories of the various reservoirs were already given in Table 4.1, where we noticed that the atmosphere is a relatively small reservoir with large fluxes, so that the residence time of C in the atmosphere is only a few years. The carbon system is not at steady state. Because of fossil fuel combustion and possibly also because of deforestation, the inventories of C in the atmosphere and hydrosphere are increasing. The flux related to fossil fiiel combustion is nearly 1 % of the total atmospheric CO2 reservoir. The flux due to land use is more con-troversal but is probably 1-2 X 10 mol C . As the summary at the bottom... 

There are, of course, several assumptions behind this apparently simple description. One is that the 834S signal of all fossil fuel is in the above range. At the moment only a rather small number of samples of power-station flue gases from limited locations have been analysed. A second assumption is that the 534S signal of seawater SO4 is not altered significantly when DMS crosses the air-sea interface and is oxidized to S02 and SO4 in the atmosphere. The evidence to date indicates that neither of these assumptions introduces much error, but more work is required to prove this approach. 

Carbon is naturally contained in all of Earth s compartments the global carbon cycle is a description of how carbon moves among those compartments in response to perturbations, such as emissions from fossil fuel burning and deforestation. Compartmental models of... 

Although the great majority of methanol is currently produced using natural gas and other fossil fuels, it can also be produced from renewable biomass. HameUnck and Faaij (2002) give a very fiiU description and analysis of the cost involved in such processes. They show that in a few years such processes should yield methanol with a process efficiency of about 60% and at a cost per Joule similar to current refined diesel and gasoline prices, though at the moment these are higher by a factor of about 3. 

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