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Clean coal technology



Clean coal is the name attributed to coal chemically washed of minerals and impurities, sometimes gasified, burned and the resulting flue gases treated with steam, with the purpose of removing sulfur dioxide, and reburned so as to make the carbon dioxide in the flue gas economically recoverable. The coal industry uses the term "clean coal" to describe technologies designed to enhance both the efficiency and the environmental acceptability of coal extraction, preparation and use[1], with no specific quantitative limits on any emissions, particularly carbon dioxide.

The burning of coal, a fossil fuel, is one of the principal causes of anthropogenic climate change and global warming [http://en.wikipedia.org/wiki/IPCC_Fourth_Assessment_Report. The concept of clean coal is said to be a solution to climate change and global warming by coal industry groups, while environmental groups believe it is greenwash. Greenpeace[2] is a major opponent of the concept because emissions and wastes are not avoided, but are transferred from one waste stream to another. The 2007 Australian of the Year, paleontologist and environmental activist Tim Flannery made the assertion that "Coal can't be clean"[3].

There are no coal-fired power plants in commercial production which capture all carbon dioxide emissions, so the process is theoretical and experimental and thus a subject of feasibility or pilot studies. It is has been estimated that it will be 2020 to 2025 before any commercial-scale clean coal power stations (coal-burning power stations with carbon capture and sequestration) are commercially viable and widely adopted.[4]. This time frame is of concern because there is an urgent need to mitigate greenhouse gas emissions and climate change to protect the world economy according to the Stern report. Even when CO2 emissions can be caught, there is considerable debate over the necessary carbon capture and storage that must follow.

Additional recommended knowledge

Contents

Byproducts

The byproducts of coal combustion are very hazardous to the environment if not properly contained. This is seen to be the technology's largest challenge, both from the practical and public relations perspectives.

While it is possible to remove most of the sulfur dioxide (SO2), nitrogen oxides (NOx) and particulate (PM) emissions from the coal-burning process, carbon dioxide (CO2) emissions and radionuclides [5] will be more difficult to address. Technologies do exist to capture and store CO2, but they have not been made available on a large-scale commercial basis due to the high economic costs[6]. For this reason renewable energy sources or nuclear power may be a more cost-effective and environmentally friendly alternative.

Potential cost of clean coal

In Carbon capture and storage under "Cost of CCS" lifetime costs for natural gas, pulverized coal and IGCC with and without carbon capture are detailed.

In a study conducted in 2003 by the IEA GHG, "the capital cost of building a Shell-designed IGCC could cost $1371 per kW-electric without carbon capture and $1860 with it."[7]

Comparisons with other energy sources can be found in Economics of new nuclear power plants.

Support

Clean Coal has been mentioned by United States President George W. Bush on several occasions, including his 2007 State of the Union Address. Bush's position is that clean coal technologies should be encouraged as one means to reduce the country's dependence on foreign oil. Senator Hillary Clinton has also recently said that "we should strive to have new electricity generation come from other sources, such as clean coal and renewables."[8].

In Australia, clean coal is often referred to by Prime Minister Kevin Rudd as a possible way to reduce greenhouse gas emissions [1]. The previous Prime Minister John Howard has stated that nuclear power is a better alternative, as clean coal technology may not prove to be economically favorable [9].

Criticism

Prominent environmentalists including Dan Becker, director of the Sierra Club's Global Warming and Energy Program, believe that the term clean coal is misleading: "There is no such thing as 'clean coal' and there never will be. It's an oxymoron". [10] Complaints focus on the environmental impacts of coal extraction, high costs to sequester carbon, and uncertainty of how to manage end result pollutants and radionuclides. There are other forms of clean and renewable energy such as solar, wind and hydroelectric which are supported by many of the environmentalist groups and campaigns.

Critics of the planned power plants contend that there is no such thing as "clean coal" and that the plant will still release large amounts of pollutants compared to renewable energy sources such as wind power and solar power. They also contend that the continuing construction of coal-powered plants (whether or not they use carbon sequestration techniques) encourages unsustainable mining practices for coal, which can strip away mountains, hillsides, and natural areas. They also point out that there can be a large amount of energy required and pollution emitted in transporting the coal to the power plants. Some people contend that sequestrian technology has yet to be used or proven on such a large scale and that it may not be successful, lead to unexpected geological instability, contaminate groundwater supplies, and that sequestered CO2 may eventually "leak" up through the ground. There are also concerns that plans to possibly pump some of the sequestered CO2 into certain oil and gas reserves to help make the fuels easier to pump out of the ground will lead to increased concentrations of CO2 in potential fuel supplies which would have to be burned off during the refining process, thus adding to global warming.[11]

See also


Industry Articles on Clean Coal

Steven Edwards, Senior Vice President and Managing Director Americas Region, Black & Veatch

  • IGCC Technology: A Promising – and Complex – Solution - World Energy Magazine Vol. 8 No. 3

Steven F. Leer, President and CEO, Arch Coal, Inc.

  • America's Vast Coal Reserves: A Pivotal Asset in an Uncertain World - World Energy Magazine Vol. 6 No. 2

Mark O’Neill, Executive Director, Australian Coal Association

  • Clean Coal: The Path to Major Reductions in Greenhouse Emissions - World Energy Magazine Vol. 8 No. 2

Ron Wood, President, Energy Engineering & Construction Division, Black & Veatch

  • The Comeback of Coal-Fired Power - World Energy Magazine Vol. 7 No. 4

Reference notes

  1. ^ AustralianCoal.com.au - Clean Coal Overview
  2. ^ GreenPeace.org - Clean Coal Myths and Facts
  3. ^ Herald Sun, Melbourne Australia February 14, 2007 04:30pm
  4. ^ David Brockway, Chief of the Energy Technology Division, CSIRO, quoted by Crikey.com.au 20 Feb 2007
  5. ^ ORNL.gov - Coal Combustion: Nuclear Resource or Danger?
  6. ^ BBC.co.uk - Clean coal technology: How it works
  7. ^ Parliamentary Office of Science and Technology (2005). Cleaner Coal. Retrieved on 2007-04-23.
  8. ^ Remarks of Senator Hillary Rodham Clinton to the Cleantech Venture Forum VIII
  9. ^ NineMSN.com.au - Interview: John Howard February 11, 2007
  10. ^ Grist.org - Coal Position
  11. ^ http://ohvec.org/links/news/archive/2005/fair_use/10_16.html
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Clean_coal_technology". A list of authors is available in Wikipedia.
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