are completed.
Although coal deposits are widely distributed, the majority (approximately 79%) of the recoverable reserves of the world are located in five regions: (i) the United States, (ii) Russia, (iii) China, (iv) Europe and Eurasia outside of Russia, and (v) Australia and New Zealand. By rank, anthracite, and bituminous coal account for approximately 47% of the estimated worldwide recoverable coal reserves on a tonnage basis, subbituminous coal accounts for 30%, and lignite accounts for 23%. As these numbers indicate, the United States has a vast supply of coal (approximately 28% of world reserves and more than 1,600 billion tons – 1,600 x 109 tons – of the remaining coal resources. The United States is also the second- largest coal producer in the world (after China) and annually produces more than twice as much coal as India, the third-largest producer of coal (Höök and Aleklett, 2009; EIA, 2010, 2011, 2012a, 2012b).
The quality and geological characteristics of coal deposits are important parameters for coal reserves. Coal is a heterogeneous source of energy, with quality (for example, characteristics such as heat, sulfur, and ash content) varying significantly by region and even within individual coal seams. At upper levels of coal quality are premium-grade bituminous coals, or coking coals, used to manufacture coke for the steelmaking process. Coking coals produced in the United States have an estimated heat content of 26.3 million Btu per ton and relatively low sulfur content of approximately 0.9% by weight. At the other end of the spectrum are reserves of low-Btu lignite – on a Btu basis, lignite reserves show considerable variation (International Energy Agency, 2010; EIA, 2010, 2011, 2012a, 2012b).
1.6.5 Other Definitions
While the definitions presented above are in common use, there are other systems of resource/reserve definition and nomenclature that are similar to the definitions used above (EWG, 2007) and also deserve mention here.
The definition of resources according to the scheme of the World Energy Council
The definition of reserves according to the scheme of the WEC is the proved amount in place, which is the resource remaining in known deposits that has been carefully measured and assessed as exploitable under present and expected local economic conditions with existing available technology. On the other hand the proved recoverable reserves is the tonnage of coal within the proved amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology.
The estimated additional reserves recoverable is the tonnage of coal within the estimated additional amount in place that geological and engineering information indicates with reasonable certainty might be recovered in the future.
The International Energy Agency (IEA),
The US Energy Information Agency (EIA)
Other national geological agencies use different definitions, such as the German Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), which
1.7 Energy Independence
Energy independence has been a political non-issue in the United States since the first Arab oil embargo in 1973. Since that time, the speeches of various presidents and the Congress of the United States have continued to call for an end to the dependence on foreign oil by the United States. The congressional rhetoric of energy independence continues but meaningful suggestions of how to address this issue remain few and far between.
Energy interdependence also makes the domestic economy more susceptible to disruptions in distant and unstable regions of the globe, such as the Middle East, South America, and Africa. In fact, in many countries with proven reserves, oil production could be shut down by wars, strikes, and other political events, thus reducing the flow of oil to the world market. If these events occurred repeatedly, or in many different locations, they could constrain exploration and production, resulting in a peak despite the existence of proven oil reserves.
Even in the United States, political considerations may affect the rate of exploration and production of energy sources. For example, restrictions imposed to protect environmental assets mean that some oil may not be produced. In addition, policies on federal land use need to take into account multiple uses of the land including environmental protection. Environmental restrictions may affect a peak in oil production by barring oil exploration and production in environmentally sensitive areas.
The government must adopt policies that ensure energy independence. The US Congress is no longer believable when the members of the Congress lay the blame on foreign governments or events for an impending crisis. In the United States, crude oil imports are considered a threat to national security but there is also the line of thinking that the level of imports has no significant impact on energy security, or even national security. However, the issue becomes a problem when import vulnerability increases as crude oil imports rise, which occurs when oil-consuming countries increase the share of crude oil imports from politically unstable areas of the world.
Currently, the United States is an exporter of crude oil and crude oil products but the question remains related to the longevity of such a situation. In addition, US dependence on crude oil has increased in recent years and this indicates two possible areas of concern regarding the extent to which crude oil influences energy security: (i) the increase in the crude oil share of energy use, and (ii) the inability or unwillingness of the United States to reduce dependence on oil. It is because of such variations that the potential of gasification must be considered as an option for energy production, particularly for the production of liquid fuels and chemicals.
For many decades, coal has been the primary feedstock for power generation but due to recent concerns related to the use of fossil fuels and the resulting environmental pollutants, irrespective of the various gas cleaning processes and gasification plant environmental cleanup efforts, there is a move to feedstocks other than coal for gasification processes (Speight, 2013). Indeed, the mounting interest in the use of mixed-coal feedstocks and non-coal feedstocks for power generation reflects
