Coal reserves

Known world coal reserves in 1990 were estimated to be about 1000—1600 biUion metric tons (4). The geographic distribution of these reserves is widespread, but about two-thirds of this coal resides in the United States, People s RepubHc of China, and the Commonwealth of Independent States. 

In 1990 coal production in the United States reached 0.9 biUion metric tons (2) and worldwide production was estimated to be over four biUion metric tons. In 1982 it was estimated that at least 50% of the world coal production was cleaned in some manner before use (3). As higher quaUty coal reserves are depleted and more stringent environmental regulations on pollutants, particularly sulfur oxides, are enacted, this percentage is expected to increase. 

The sulfur content of U.S. coals varies widely, ranging from a low of 0.2 percent to as much as 7 percent by weight, on a diy Basis. The estimated remaining U.S. coal reserves of all ranks, by sulfur content, are shown in Fig. 27-1. Extensive data on sulfur and sulfur reduc tion potential, including washability, in U.S. coals are given in Sulfur and Ash Reduction Potential and Selected Chemical and Physical Properties of United States Coal (U.S. Dept, of Energy, DOE/PETC, TR-90/7, 1990 TR-91/1 andTR-91/2, 1991). 

FIG. 27-1 Estimates of recoverable U.S, coal reserves in Gt by sulfur ranges and region, To convert tonnes to US tons, multiply by 1,102 and mg/MJ to Ib/lO " Btii, multiply by 2,321, (Source U,S, Coal Reserves An Update by Heat and Sulfur Content, Energy Information Administration, DOE/E1A-0529(92), Fehruary 1993.)... 

There are many benefits for using hydro resources to produce electricity. First, hydropower is a renewable resource oil, natural gas, and coal reserves may be depleted over time. Second, hydro resources are indigenous. A country that has developed its hydroelectric resources does not have to depend on other nations for its electricity hydroelectricity secures a country s access to energy supplies. Third, hydroelectricity is environmentally friendly. It does not emit greenhouse gases, and hydroelectric dams can be used to control floods, divert water for irrigation purposes, and improve navigation on a river. 

Coal is a natural combustible rock composed of an organic heterogeneous substance contaminated with variable amounts of inorganic compounds. Most coal reserves are concentrated in North America, Europe, and China. 

In many regions of the world coal reserves represent substantial indigenous resources, and for this reason coal will always play an important role in the future of power generation. Inevitably, coal is more difficult to handle and has less appeal than other clean-burning fuels such as gas. However, substantial progress has been made in modern efficient handling techniques and combustion methods that can give clean combustion with low emissions. 

The economically recoverable coal reserves are of the order of 4.2 x 10 tee, which, with an annual consumption of around 111 x 10 tee, gives a life of 38 years. However, the recoverable coal reserves are much greater, at 30 X 10 tee or 270 years supply. 

Tphe Middle East oil crisis increased natural gas needs, and dwindling gas reserves have intensified the need to use our huge coal reserves for the synthesis of gas, especially methane. Energy requirements will double in the next 10 years and triple before the turn of the century. Use of pipeline gas has been increasing by 6% per year, almost double the overall energy demand. The rate of gas discovery in the United States has not kept pace with use, and the estimated reserves of some 2,500 trillion cubic feet could easily be depleted in 25 years. Liquid natural gas is imported to ease shortages, but it is 5-10 times as expensive as natural gas. 

Prior to World War II, this was the principal organic chemical raw material. It is more difficult to process than oil, hut most European countries and the U.S. have very large coal reserves. However, it is nonrenewahle. 

Another key feature of sulfur chemistry is the Lewis acidity of sulfur dioxide. Sulfur dioxide is a common atmospheric pollutant that results from burning coal to produce electricity. Most coal reserves in North America include significant amounts of sulfur-containing impurities. When coal is burned, sulfur combines with O2 to form SO2, a hard Lewis acid. 

Furthermore, vast reserves, such as tar sand and gas hydrates, await technology to enable their economically and environmentally sound exploitation. Large coal reserves can also be exploited, for example through gasification and Fischer-Tropsch synthesis. 

In the rest of this section, coal liquefaction researchers of the United States, South Africa, Australia, Japan, Canada, and Great Britain describe their country s coal reserves and origins, and the significance of coal composition to liquefaction behavior. 

GEOGRAPHICAL LOCATION AND COAL RESERVES OF SOUTH AFRICA... 

Region Theoretical Minable Coal Reserves Total... 

Coal reserves up to the present depth levels of mining technology. 

Coal accounts for 90% of the proven energy reserves in the United States, and is a source of fuel for nearly half of the nation s electricity, typically via combustion in pulverized coal (PC)-fired boilers. While the U.S. is rich in coal reserves,... 

The current proven coal reserves of the United States are predicted to support this production level for 200 years. This liquefied coal reserve exceeds the proven oil reserves of the entire world. The reactors could also produce hydrogen or gaseous hydrocarbons from the coal as well. The excess heat from nuclear power plants could be used for central heating. 

Coal is the most abundant fossil fuel in the U.S. and many other countries. In the U.S. coal makes up about 95% of all fossil energy reserves. These reserves could last several hundred years at the current level of coal consumption. Major developing countries such as China and India, which are now using more and more of the world s oil, also have large coal reserves. 

Table 3.9. Worldwide hard coal reserves and resources, 2005...

Hard coal reserves Hard coal resources ... 

Table 3.9 shows the distribution of world hard coal reserves and resources in 2005. Total reserves amounted to 728 Gt (626 Gtce), of which the vast majority are located in the USA and China, followed by India and Russia. The top ten countries represent 85% of total reserves. Considering the production of 2005, the static lifetime of hard coal can be calculated at around 150 years however, we should acknowledge the simplicity of this approach, as coal use is expected to increase significantly in the future. As for hard coal resources, whose quantification is more uncertain, Russia is leading, followed by China and the United States. Figure 3.22 shows the geographical distribution of cumulative production, reserves and resources of hard coal. 

TABLE 24-2 Estimate of Recoverable U.S. Coal Reserves by Sulfur Ranges and Regions (Pg)... 

The worldwide coal production and consumption in 1998 were 5043 and 5014 million short tons, respectively. The known world recoverable coal reserves in 1999 were 1087 billion short tons (AER, 1999 lEA, 2000). Coal reserves are rather evenly spread around the globe 25% ate in the USA, 16% in Russia, and 11.5% in China. Although coal is much more abundant than oil and gas on a global scale, coalfields can be depleted in a region. The known world recoverable coal reserves in 1999 were 989 billion tons. 

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