Fossil fuels, CO2 emission

For this base year (1994) the cumulative fossil fuel CO2 emission is 238 10 g CO2—C (Boden 2009) hence, 50 % of the CO2 added to the atmosphere is captured by the world s oceans. The total oceanic dissolved carbonate carbon (Table 2.9) corresponds to 0.028 g as carbon in seawater taking into account the volume of the world s oceans (Table 2.3). The experimentally estimated seawater standard carbonate carbon is 0.0244 g L seawater (Dickson et al. 2007). In the first 200 m of the ocean, the total deposited anthropogenic CO2 (Table 2.82 and assuming that 30% is within this layer) only contributes to 3% to dissolved inorganic carbon (DIC). Hence, it is very difficult to measure trends in the DIC because of manmade changes (see Fig. 2.96). 

Boden, T. A., G. Marland and R. J. Andres (2009) Global, regional, and national fossil-fuel CO2 emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US. Department of Energy, Oak Ridge, Tenn., U.S.A. doi 10.3334/CDIAC/ 00001... 

FIGURE 3.2 Regional fossil fuel CO2 emissions. SOURCE IPPC (1992). 

The projection of future emissions of fossil fuel CO2 is subject to a number of uncertainties. The growth rate has already shown great variations and the reserves of fossil fuels are not... 

Often, many simultaneously occurring pollutants or contaminants determine an environmental problem. In industry, agriculture, and households, products are often mixtures of many compounds. The process of production and consumption is accompanied by emissions and consequently by contamination. One example is the use of toxaphene in the past, a very complex mixture of polychlorinated camphenes, as a pesticide. Technical toxaphene consists of more than 175 individual compounds. A second example is industrial and domestic emissions resulting from the combustion of fossil fuels. The emissions contain both a mixture of gases (SO2, NOx, CO2, etc.) and airborne particulate matter which itself contains a broad range of heavy metals and also polycyclic aromatic hydrocarbons (PAH). 

The principal anthropogenic sources of CO 2 are the burning of fossil fuels and the production of cement. Total CO2 emissions can be estimated based on statistics of fossil fuel use and cement production (Andres et al., 1994). Average 1980 to 1989 fossil fuel combustion emissions have been estimated as 5.5 Gt(C) yr. During 1991, estimated total emissions were 6.2 Gt(C). Cumulative CO2 emissions since the preindustrial era have been estimated as approximately 230 Gt of carbon (Andres et al., 1994), which represents about 30% of the current amount of CO 2 in the atmosphere (Figure 21.11). 

As seen from Table 2.50, only three anthropogenic activities contribute substantially to emissions on a global scale stationary combustion of fossil fuels (CO2 and SO2), mobile combustion of fossil fuels (CO2, CO, and NMVOC), and agriculture (CH4, NH3, N2O). 

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). 

Fig. 11-21 Annual CO2 emissions from each type of fossil fuel with growth rates (Rotty, 1981).

The atmospheric CO2 content increased by about 1 ppmv per year during the period 1959-1978 (Bacastow and Keeling, 1981) with the South Pole Pco increase lagging somewhat behind the Mauna Loa (19.5°N,155.6 "W) data. This difference is consistent with our knowledge of interhemispheric mixing times and the fact that most fossil fuel emissions occur in the northern hemisphere (see also Conway et al, 1994a). 

Fossil fuel emissions alter the isotopic composition of atmospheric carbon, since they contain no C and are depleted in C. Releasing radiocarbon-free CO2 to the atmosphere dilutes the atmospheric C content, 3delding lower C/C ratios ("the Suess effect"). From 1850 to 1954 the C/C ratio in the atmosphere decreased by 2.0 to 2.5% (Fig. 11-23) (Suess, 1965 Stuiver and Quay, 1981). Then, this downward trend in C was disrupted by a series of atmospheric nuclear tests. Many large fission explosions set off by the United States with high emission of neutrons took place in 1958 in the atmosphere and the Soviet Union held extensive tests during... 

Marland, G., Boden, T. A., Griffin, R. C., Huang, S. F., Kanciruk, P. and Nelson, T. R. (1989). Estimates of CO2 emissions from fossil fuel burning and cement manufacturing, based on the US Bureau of Mines cement manufacturing data. Rep. ORNL/CDIAC-25, NDP-030, Carbon Dioxide Information Analysis Center, Oak Ridge Natl. Lab., Oak Ridge, TN. 

The rapid pace of development of our world over the last century has heen largely based on easy access to fossil fuels. These resources are, however, limited, while their demand is growing rapidly. It is also becoming clear that the scale of carbon dioxide (CO2) emissions following the use of fossil fuels is threatening the climate of the Earth. This makes the development of sustainable production and energy solutions in industry, transportation, and households the most important scientific and technical challenge of our time. 

Worldwide, approximately 300 million tonnes of wastes per year are sent in blended form to cement plants to replace fossil fuels (up to 20%) and for use as inputs (up to 6%), thus contributing to reduce CO2 emissions [2]. This demonstrates its importance in saving natural resources. 

The world energy consumption for industrial and human activities has burned more than 10 billion tons of fossil fuels per year (in coal equivalent). This is the major reason for increase CO2 emission (Fig. 4). 

The total GHGs emission is the sum of GHGs emission from RDF pretreatment (of 4.1) and utilization step (of 4.2) converted to kg CO2/MJ. This unit is used to compare GHGs emission from RDF samples and from fossil fuel (Fig. 18). 

By calculating the total GHGs emission from pretreatment and utilization step of RDF, converted to kg CO2/MJ, a figure of GHGs emission from RDF sample compare with fossil fuel has been presented. Result showed an advantage of RDF to fossil fuels because it leads to the less GHG emissions. 

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