Acid Deposition Long-Term Trends (1986) / Chapter Skim
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2. Emissions of Sulfur Dioxide and Nitrogen Oxides and Trends for Eastern North America
2. Emissions of Sulfur Dioxide and Nitrogen Oxides and Trends for Eastern North America
Pages 48-92
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From page 48... ...
The production and fate of these compounds will not be discussed further in this chapter. We continue removing or mining carbon, sulfur, nitrogen, and crustal material from the Earth's long-term reservoir for two purposes: to "produce" energy from the fossil fuels and to manufacture from extracted minerals disposable or permanent objects for societal use.
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From page 49... ...
Thus human activities significantly enhance the natural redistribution of the Earth's crustal material over eastern North America. Over the past 100 years the average emission density over eastern North America was about 1-2 g sulfur m~2 yr~ .
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From page 50... ...
. Producing activities include energy production (fossil fuels)
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From page 51... ...
51 NATU RAL CH EM ICAL CYCLI NG Pla nts External world ~V' Animals Microorga nisms Producers ~ - [ Recyclers FLOW OF CHEMICALS FROM HUMAN ACTIVITY _ Mobi I izers Prod ucers J L External world _~.
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From page 52... ...
In principle, every producer, i, may deliver its product to any consumer, j. Mathematically, this producer-consumer transfer is characterized by a surface transfer matrix, Al]
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From page 53... ...
is the fuel and metals production rate at a given mining region, ci (weight fraction) is the concentration of sulfur in fuel and ore, and sij is a dimensionless transfer matrix element between producer S and consumers of fuel and ores.
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From page 54... ...
~ l ,' 'GRS 25 i! ''' _ 30 20 15 _ 10 _ 5 O ~ ,.~ l., ,lt~l.~ -I ~''-' - 1 ~ ,,,I.~ il,l.ll , l O 850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 t97Q 1980 1990 2000 TERR Illllll l Illllllll Illllllll Illllllll Illllllll lIIIIIIII Illllllll Illllllll Illlllill ~rlllllll Ir~l I I I I !
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From page 55... ...
Coal consumption declined to another minimum in 1960, because the increasing energy demands were supplied by cleaner fuels, natural gas and petroleum. Accelerated oil and gas consumption began in the late 1930s and 1940s, such that by 1950 the energy supplied by oil exceeded that of coal and maintained its rise up to the early 1970s.
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From page 56... ...
. The significance of these shifts to sulfur emissions is that each coal-producing district has its own range of sulfur content: a shift in the relative production rate results in a change of the average sulfur content and sulfur production.
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From page 57... ...
57 Sulfur Content The next parameter that will be examined is ci, the concentration of the contaminant sulfur, for each coal-producing regione Knowing the production rate P and concentration ci permits the calculation of the mass of contaminant, Mi = ciPi, that is mobilized by each producer. 180 170 - 180150 140 130 120 110 ~oo 90 ~o 70 ~0 50 40 30 20 10 b Pennsylvania ~ / .
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From page 58... ...
58 o I J o~ ~\\\\\~ o ~o o ~ ~ ~ N ' A Z o tr C~ _ ~ ~n ~_ 0 10 0 a 0 0 ~ _ _ 0 (SUol Uo!
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From page 59... ...
On the other hand, the districts in the Midwest produce coal ranging from 2 to 4 percent sulfur, with little production outside this range. Thompson and York (1975)
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From page 60... ...
The data are averaged for the 9-year period from 1970 to 1978. SOURCE: Energy Information Administration 1981.
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From page 61... |
From page 62... ...
Hence, while U.S. coal production has increased in the 1970 to 1980 period from about 500 to 800 million tons/yr, the corresponding increase of the coal sulfur mobilization was only about 12 percent.
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From page 63... ...
It appears that Pennsylvania, West Virginia, and Ohio account for almost half of the Appalachian coal consumption. The normalized transfer matrix for Interior coal shows that most of it is consumed within the interior region (Figure 2.13(b)
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From page 64... ...
of sulfur distribution function (solid line) of coals shipped from the Appalachian, Interior, and Western coal mining regions.
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From page 65... ...
Coal Consumption In the early l900s coal was the nation's major fuel, supplying almost 90 percent of its energy needs. Later, coal's importance declined, mainly because of competition from petroleum and natural gas.
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From page 66... ...
B I 7 tr: 1 1 1 31 al 1 1 O- ~ .G~,...................... 1880 18BO 1900 1920 1940 1960 1980 2000 YEAR FIGURE 2.11 Trends in coal sulfur production for the Appalachian, Interior, and Western coal-producing regions.
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From page 67... ...
Together, these states account for about one third of the coal consumed in the United States. In 1975, coal consumption was about 550 million tons/yr, roughly the same as around 1920 and 1943 (Figure 2.15)
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From page 68... ...
~` I ~ (~ b INTERIOR COAL c WESTE R N COAL hi CONSUMPTION (%) ~` FIGURE 2.13 Normalized surface transfer maps of shipment to consumer states from coal producing regions.
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From page 69... ...
By 1974, the seasonal pattern of coal use was determined by the winter and summer peaks of utility coal use. The seasonal shift of coal sulfur emissions has undoubtedly resulted in significant changes in seasonal patterns in acid deposition.
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From page 70... ...
coal consumption by consuming sector. SOURCES: Mineral Resources of the United States, Yearbooks (U.S.
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From page 71... ...
1974. Data from Mineral Yearbooks (U.S.
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From page 72... ...
. For comparison, coal consumption density for 1975, calculated and plotted in a similar manner, is given in Figure 2.18 (b)
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From page 73... ...
73 in d ~^ -~ a, Al o ~ UP I_ o .
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From page 74... ...
The emitted sulfur from oil products is calculated as crude oil sulfur content minus recycled sulfur. AS seen in Figure 2.21, the oil sulfur emission estimated in this manner ranged between 3 and 4 million tons/yr for the
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From page 75... ...
Since then, there has been a significant decrease, caused primarily by declining imports and the increasing fraction of recycled sulfur. For 1982, emissions of sulfur from oil consumption were about 2 million tons/yr, which is less than 20 percent of the sulfur emissions from coal.
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From page 76... ...
With respect to air pollution, natural gas is the cleanest of the fossil fuels, and sulfur emissions from combustion of natural gas are negligible. Copper and Zinc Smelting Significant production of copper began in the United States about 1895 and reached approximately 1 million tons annually by 1920.
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From page 77... ...
However r acid production is practical only from converter gases. With tightly hooded converters, 50 to 70 percent of the sulfur oxides can be removed; removal of additional sulfur oxides requires scrubbing.
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From page 78... ...
These include sulfur emissions in the eastern United States and southeastern Canada from coal and oil combustion and copper and zinc smelting. The Canadian emission trends were taken from the United States-Canada Memorandum of Intent (1982)
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From page 79... ...
trend in sulfur emissions from copper and zinc smelting. SOURCES: Mineral Resources of the United States, Yearbooks (U.S.
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From page 80... ...
Currently, sulfur emissions in the subcontinent are estimated to range between 11 and 15 million tons/yr (22 to 30 million tons of sulfur dioxide/yr)
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From page 81... ...
Another increase occurred in the early 1940s, followed by a decrease in the late 1940s and l950s, an increase in the 1960s, and a decrease in the 1970s. Current sulfur dioxide emissions are comparable
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From page 82... ...
Estimating historical emission trends of nitrogen oxides is difficult because most of the nitrogen oxide is formed by the fixation of atmospheric nitrogen at high temperatures of combustion rather than by oxidation of the nitrogen contained in the fuel. The nitrogen oxide emissions depend primarily on the combustion temperature
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From page 83... ...
Since combustion processes in internal-combustion engines and boilers have undoubtedly changed since the turn of the century, it is likely that nitrogen oxide emission factors also have changed historically. Because combustion parameters can vary randomly over a wide range, and because information on historical combustion processes is generally lacking, assumptions concerning changes in emission factors over time constitute the major source of uncertainty in developing trends in nitrogen oxide emissions.
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From page 84... ...
The emission factor for other petroleum products was assumed to be constant over time. Based on these estimates of emission factors and data on fuel consumption, regional emission trends were calculated (Figure 2.27)
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From page 85... ...
Evidently, there has been no significant change since the mid-1970s. The nitrogen oxide emission estimates for Region B are given in Figure 2.27(b)
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From page 86... ...
Currently, the emission densities in the two regions are almost equivalent. COMPARISONS WITH OTHER TREND ESTIMATES Sulfur Dioxide The methodology presented in this chapter for estimating sulfur emission trends is for the most part similar to other approaches found in the literature.
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From page 87... ...
Nitrogen Oxides Gschwandtner et al.
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From page 89... ...
Coal combustion accounts for most of the current sulfur emissions, which are estimated to be between 11 and 15 million tons of sulfur/yr. Sulfur mobilization by oil products increased from the 1940s until about the 1960s, when it leveled off at 3 to 4 million tons of sulfur/yr.
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From page 90... ...
In eastern North America, sulfur dioxide emissions showed the most rapid rate of increase in the period from approximately 1880 to 1910. Since then sulfur emissions have increased overall by about SO percent, but the increase has not been monotonic.
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From page 91... ...
1985. Historic emissions of sulfur and nitrogen oxides in the United States from 1900 to 1980.
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From page 92... ...
1977. Compilation of Air Pollutant Emission Factors.
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