Clean coal technology is an umbrella term used to describe technologies being developed that aim to reduce the environmental impact of coal energy generation. These include chemically washing minerals and impurities from the coal, gasification (see also IGCC), treating the flue gases with steam to remove sulfur dioxide, carbon capture and storage technologies to capture the carbon dioxide from the flue gas and de-watering lower rank coals (brown coals) to improve the calorific quality, and thus the efficiency of the conversion into electricity.
Clean coal technology usually addresses atmospheric problems resulting from burning coal. Historically, the primary focus was on sulfur dioxide and particulates, since it is the most important gas in the causation of acid rain. More recent focus has been on carbon dioxide (due to its impact on global warming) as well as other pollutants. Concerns exist regarding the economic viability of these technologies and the timeframe of delivery, potentially high hidden economic costs in terms of social and environmental damage, and the costs and viability of disposing of removed carbon and other toxic matter.
Coal, which is primarily used for the generation of electricity, is the second largest domestic contributor to carbon dioxide emissions in the USA. The public has become more concerned about global warming which has led to new legislation. The coal industry has responded by running advertising touting clean coal in an effort to counter negative perceptions, as well as by putting more than $50 billion towards the development and deployment of clean coal technologies, including carbon capture and storage. The expenditure has been unsuccessful to date in that there is not a single commercial scale coal fired power station in the US that captures and stores more than token amounts of CO2.
The world’s first “clean coal” power plant went on-line in September 2008 in Spremberg, Germany. The plant is state-owned and has been built by the Swedish firm Vattenfall. The plant is state owned because of the high costs of this technology, since private investors are only willing to invest in other sources such as nuclear, solar and wind. The facility captures CO2 and acid rain producing sulfides, separates them, and compresses the CO2 into a liquid state. Plans are to inject the CO2 into depleted natural gas fields or other geological formations. This technology is considered to not be a final solution for CO2 reduction in the atmosphere, but provides an achievable solution in the near term while more desirable alternative solutions to power generation can be made economically practical.
Clean Coal and the environment
According to the United Nations Intergovernmental Panel on Climate Change, the burning of coal, a fossil fuel, is a major contributor to climate change and global warming. (See the UN IPCC Fourth Assessment Report). As 25.5% of the world’s electrical generation in 2004 was from coal-fired generation (see World energy resources and consumption), reaching the carbon dioxide reduction targets of the Kyoto Protocol will require modifications to how coal is utilized.
Some in the coal industry and the U.S. Department of Energy refer to carbon capture and sequestration (CCS) as the latest in “clean coal” technologies. The “clean coal” terminology is generally not endorsed by professionals in CCS, and is actively opposed by environmental organizations that favor CCS. CCS is a means to capture carbon dioxide from any source, compress it to a dense liquid-like state, and inject and permanently store it underground. Currently, there are more than 80 carbon capture and sequestration projects underway in the United States. All components of CCS technology have been used for decades in conjunction with enhanced oil recovery and other applications; commercial-scale CCS is currently being tested in the U.S. and other countries. Proposed CCS sites are subjected to extensive investigation and monitoring to avoid potential hazards, which could include leakage of sequestered CO2 to the atmosphere, induced geological instability, or contamination of aquifers used for drinking water supplies.
Supporters of clean coal use the Great Plains Synfuels plant to support the technical feasibility of carbon dioxide sequestration. Carbon dioxide from the coal gasification is shipped to Canada where it is injected into the ground to aid in oil recovery. Supporters acknowledge that economics can be problematic for carbon sequestration.
Clean coal
Clean coal is a term most often used by the media in news stories that reference carbon capture and storage/sequestration (CCS). The phrase “clean coal” is also referred to as “cleaner coal” in an attempt to mitigate criticism. These technologies are in development and aim to reduce CO2 at coal fired power plants in order to mitigate climate change. Scientific consensus on climate change is that it is caused by human activities, which increase production of CO2 and other greenhouse gases. Carbon capture and storage is intended to reduce emissions from coal–fired power generation, which is one of the greatest sources of global warming pollution contributing more emissions than all automobiles in the United States. There is no agreement across groups as to when CCS will be available on a commercial scale. Industry leaders emphasize that the technology should be available by 2020. Meanwhile, others question its feasibility in that time frame. The Intergovernmental Panel on Climate Change suggests that industrialized or “annexe 1″ countries need to reduce greenhouse gas emissions by between 25 and 40% by 2020. No commercial scale coal-fired power plant currently exists that captures the majority of its emissions.
The US Department of Energy continues to work with private industry in developing advanced clean coal technologies. One of the clean coal technologies being developed is carbon capture and sequestration, which is currently being tested at existing coal-based plants throughout the world. Perhaps the most popular example of a coal-based plant using carbon capture technology is Vattenfall’s Schwarze Pumpe plant in Germany. Another technology under development is Integrated Gasification Combined Cycle or IGCC.
Other clean coal technologies include those that that dewater low rank coals. Low rank coals often contain a higher level of moisture content which contains a lower calorific content per tonne. This causes a reduced burning efficiency and an increased emissions output. Reduction of moisture from the coal prior to combustion can reduce emissions by up to 50 percent.
It has been estimated that commercial-scale clean-coal power stations (coal-burning power stations with carbon capture and sequestration) cannot be commercially viable and widely adopted before 2020 or 2025. This time frame is of concern to environmentalists because, according to the Stern report, there is an urgent need to mitigate greenhouse gas emissions and climate change.
Clean Coal and the environment
According to the United Nations Intergovernmental Panel on Climate Change, the burning of coal, a fossil fuel, is blamed for climate change and global warming. (See the UN IPCC Fourth Assessment Report). As 25.5% of the world’s electrical generation in 2004 was from coal-fired generation (see World energy resources and consumption), reaching the carbon dioxide reduction targets of the Kyoto Protocol will require modifications to how coal is utilized.
Sequestration technology has yet to be tested on a large scale and may not be safe or successful. Sequestered CO2 may eventually “leak” up through the ground, may lead to unexpected geological instability or may cause contamination of aquifers used for drinking water supplies. There are also concerns that plans to 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. This would have to be removed or released during the refining process.
Technologies related to reducing the environmental impact of extracting energy from coal do not address environmental impacts of coal mining. Examples of environmental impacts of coal mining include the Kingston Fossil Plant coal fly ash slurry spill.
Byproducts
The byproducts of coal combustion are considerably hazardous to the environment if not properly contained.
While it is possible to remove most of the sulfur dioxide (SO2), nitrogen oxides (NOx) and particulate matter (PM) emissions from the coal-burning process, carbon dioxide (CO2) emissions and radionuclides will be more difficult to address.
Coal-fired power plants are the largest aggregate source of mercury: 50 tons per year come from coal power plants out of 150 tons emitted nationally in the USA and 5000 tons globally. In the USA, neither the combustion products of oil, nor their associated solid or liquid waste streams, are considered to be major contributors to mercury pollution.
Potential cost of clean coal
Whether clean coal technology is adopted worldwide will …“depend less on science than on economics. Cleaning coal is very expensive.”
Projected costs for carbon capture and storage (CCS) can be found in that article. Credit Suisse Group says $15 billion needs to be invested in CCS over the next 10 years for it to play an important role in climate change. The International Energy Agency says $20 billion is needed. The Pew Center on Global Climate Change says the number is as high as $30 billion. Those figures dwarf the actual investments to date.
In the US, the Bush administration spent about $2.5 billion on clean coal technology — a large amount, but far less than what will be needed. CCS proponents say both the government and the private sector need to step up their investments.
FutureGen
FutureGen is a US government project, announced by President George W. Bush in 2003 to build a near zero-emissions coal-fueled power plant to produce hydrogen and electricity while using carbon capture and storage. Funding for the plant was withdrawn by the Department of Energy on 29 January 2008.
Support and Criticism
Support
In the United States, clean coal was been mentioned by former President George W. Bush on several occasions, including his 2007 State of the Union Address. Bush’s position was that clean coal technologies should be encouraged as one means to reduce the country’s dependence on foreign oil.
During the 2008 US Presidential campaign, both candidates John McCain and Barack Obama expressed interest in the development of clean coal technologies as part of an overall comprehensive energy plan. The development of clean coal also creates the possibility of international business for the United States and other world markets.
In 2009, President Obama included $3.4 billion in his stimulus package for advanced clean coal technologies, including carbon capture and sequestration demonstration projects.
Current Secretary of State Hillary Clinton has said that “we should strive to have new electricity generation come from other sources, such as clean coal and renewables,” and current Energy Secretary Dr. Steven Chu has said that “It is absolutely worthwhile to invest in carbon capture and storage,” noting that even if the U.S. and Europe turned their backs on coal, developing nations like India and China would not.
In Australia, clean coal is often referred to by Prime Minister Kevin Rudd as a possible way to reduce greenhouse gas emissions. (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.)
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”. The Sierra Club’s Coal Campaign has launched a site refuting the clean coal statements and advertising of the coal industry.
I say this based on my experience as the former head of the TVA, which bought and burned more than 30 million tons of coal a year. I was deeply involved in the strip mining, underground mining, trucking, and most importantly, the burning of huge quantities of coal. No one who has been deeply involved with coal can rightfully say it is clean.—S. David Freeman”Winning Our Energy Independence: An Energy Insider Shows How”
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.
Critics of the planned power plants assert 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.
The 2007 Australian of the Year, paleontologist and influential environmental activist Tim Flannery made the assertion that the concept of clean coal might not be viable for all geographical locations.
Critics also point out 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. Also, scrubbers will do nothing to reduce greenhouse gases:
Scrubbers remove some particulates, SO2, Hg(2+), and SO3 – pollution that causes smog – but they will do nothing to reduce greenhouse gas emissions that cause global warming. In fact, scrubbers are energy intensive and could lead to more of these emissions, leaving us further unable to meet Kyoto targets.—Cherise Burda, The Pembina Institute
The Reality Coalition, a nonprofit organization composed of Alliance for Climate Protection, Sierra Club, National Wildlife Federation, the Natural Resources Defense Council and the League of Conservation Voters, ran a series of television commercials in 2008 and 2009. The commercials were highly critical of clean coal, stating that there are no clean coal power plants in existence in the U.S and that without capturing CO2 emissions and storing it safely that it cannot be called clean coal.
Greenpeace is a major opponent of the concept because they view emissions and wastes as not being avoided but instead transferred from one waste stream to another.
Prior terminology
Clean coal was an umbrella term used to describe methods that have been developed to reduce the environmental impact of coal-based electricity, which accounts for nearly half of the United States’ electricity supply. These efforts include chemically washing minerals and impurities from the coal, gasification (see also IGCC), treating the flue gases with steam to remove sulfur dioxide, carbon capture and storage technologies to capture the carbon dioxide from the flue gas and coal de-watering technologies to improve the calorific quality and thus the efficiency of burning coal for energy. These methods and the technology used are described as clean coal technologies. Figures from the Environmental Protection Agency show that these technologies have made today’s coal-based generating fleet 77 percent cleaner on the basis of regulated emissions per unit of energy produced.
While the term “clean coal” is today commonly used to describe carbon capture technologies, the earliest use of the term can be traced back to U.S. Senate Bill 911 in April, 1987:
“The term clean coal technology means any technology…deployed at a new or existing facility which will achieve significant reductions in air emissions of sulfur dioxide or oxides of nitrogen associated with the utilization of coal in the generation of electricity.”
It was in the late 1980s and early 1990s that the U.S. Department of Energy (DOE) conducted a joint program with the industry and State agencies to demonstrate these technologies large enough for commercial use. The program, called the Clean Coal Technology & Clean Coal Power Initiative, has had a number of successes that have reduced emissions and waste from coal-based electricity generation. Moreover, the Program has met regulatory challenges by incorporating nitrogen oxide (NOx) control technologies “into a portfolio of cost-effective regulatory compliance options for the full range of boiler types.” This portfolio has positioned the U.S. as a top exporter of clean coal technologies such as those used for NOx. The DOE continues its programs and initiatives through regional sequestration partnerships, a carbon sequestration leadership forum and the Carbon Sequestration Core Program, a carbon capture and sequestration research and development program.
According to a report by the assistant secretary for fossil energy at the U.S. Department of Energy, clean coal technology has paid measurable dividends. Technological innovation introduced through the CCT Program now provides consumers cost-effective, clean, coal-based energy.
Sulfur dioxide (SO2) and nitrogen dioxide (NO2) control technologies emerging from clean coal technology have moved into the utility and industrial marketplace and now provide cost-effective regulatory compliance. A new generation of advanced coal-based power systems has been placed in commercial service that represents a quantum leap forward in terms of efficiency and environmental performance. These advanced power systems projects will provide a springboard for widespread, global deployment. This in turn will contribute greatly to reductions in greenhouse gas emissions.
The government and industry officials continue to use the term “clean coal” to describe technologies designed to enhance both the efficiency and the environmental acceptability of coal extraction, preparation and use, however today the term “clean coal technology” is usually used in reference to carbon capture and storage, an advanced process that eliminates carbon dioxide emissions from coal-based plants and permanently sequesters them.
In the early 20th century, prior to World War II, “clean coal” (also called “smokeless coal”) referred to anthracite and high-grade bituminous coal, used for cooking and home heating.
