User:AszlynA/Coal pollution mitigation

Coal Pollution Mitigation (Edit)
LEAD

Coal Pollution Mitigation, sometimes also known as Clean Coal, is a series of systems and technologies that seek to mitigate (reduce harmful or unpleasant chemicals) the health and environmental impact of coal; in particular air pollution from coal-fired power stations, and from coal burnt by heavy industry. Clean Coal primarily focuses on removing sulfur dioxide (SO2) and nitrogen oxides (NOx), the most important gasses that cause acid rain; and particulates that cause visible air pollution, illness, and premature deaths. It also reduces  fly ash and reduces emissions of radioactive materials. Mercury emissions can be reduced by up to 95%. Capturing carbon dioxide emissions from coal is also being pursued.

DESCRIPTION

   When you burn coal, you release various chemicals into the air such as; Mercury, lead and other heavy metals, sulfur dioxide (SO2), and nitrogen oxides (NOx), which contribute to acid rain and respiratory illnesses, particulates, which contribute to smog, haze and respiratory illness as well and lung disease, carbon dioxide (CO2) (which is the primary greenhouse gas produce from burning fossil fuels), and finally radioactive materials, such as uranium for the coal.

Coal pollution mitigation is a series of systems and technologies that seek to mitigate the health and environmental impact of coal; in particular air pollution from coal-fired power sta nd from coal burnt by heavy industry. Primarily focuses on  sulfur dioxide (SO2) and nitrogen oxides (NOx), the most important gasses that cause acid rain; and particulates which cause visible air pollution, illness, and premature deaths.

SO2 can be removed by flue-gas desulfurization and NO2 by selective catalytic reduction (SCR). Particulates can be removed with electrostatic precipitators. Although perhaps less efficient, wet scrubbers can remove both gasses and particulates. Reducing fly ash reduces emissions of radioactive materials. Mercury emissions can be reduced by up to 95%. Capturing carbon dioxide emissions from coal is a process in which a relatively pure stream of carbon dioxide (CO2) from industrial sources is separated, treated, and transported to a long-term storage location.: 2221

BACKGROUND

Environmental impact of coal[edit]
Main article: Health and environmental impact of the coal industry

According to the United Nations Intergovernmental Panel on Climate Change, the burning of coal, a fossil fuel, is a major contributor to global warming. As 26% of the world's electrical generation in 2004 was from coal-fired generation, reaching the carbon dioxide reduction targets of the Kyoto Protocol will require modifications to how coal is utilized.

Coal, which is primarily used for the generation of electricity, is the second largest domestic contributor to carbon dioxide emissions in the US. 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 to counter negative perceptions and claiming more than $50 billion towards the development and deployment of "traditional" clean coal technologies over the past 30 years; and promising $500 million towards carbon capture and storage research and development. There is still concern about clean coal technology being perceived as more environmentally friendly than it is, and the term "Clean Coal" has been used as an example of "greenwashing". According to the Sierra Club, "Despite the industry's hype, there's no such thing as 'clean coal.' But new technologies and policies can help reduce coal plants' deadly emissions."

Measurement of pollution and availability of pollution data[edit]
In some countries, such as the EU, smokestack measurements from individual power plants must be published. Whereas in some countries, such as Turkey, they are only reported to the government, not the public. However, since the late 2010s satellite measurements of some pollutants have been available.

Combustion by-products[edit]
By-products of coal combustion are compounds that are released into the atmosphere as a result of burning coal. Coal includes contaminants such as sulfur compounds and non-combustible minerals. When coal is burned, the minerals become ash (i.e. particulate matter or PM), and the sulfur forms sulfur dioxide (SO2). Since air is mostly nitrogen, the combustion of coal often leads to the production of nitrogen oxides. Sulfur dioxide and nitrogen oxides are the primary causes of acid rain. For many years—before greenhouse gasses were widely understood to be a threat—it was thought that these by-products were the only drawback to using coal. These by-products are still a problem, but they have been greatly diminished in most advanced countries due to clean air regulations. It is possible to remove most of the sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM) emissions from the coal-burning process. For example, various techniques are used in a coal preparation plant to reduce the amount of non-combustible matter (i.e. ash) in the coal before burning. During combustion, fluidized bed combustion is used to reduce sulfur dioxide emissions. After burning, particulate matter (i.e. ash and dust) can be reduced using an electrostatic precipitator, and sulfur dioxide emissions can be further reduced with flue-gas desulfurization. Trace amounts of radionuclides are more difficult to remove.[ citation needed]

Coal-fired power plants are the largest aggregate source of the toxic heavy metal mercury: 50 tons per year come from coal power plants out of 150 tons emitted nationally in the US and 5000 tons globally. However, according to the United States Geological Survey, the trace amounts of mercury in coal by-products do not pose a threat to public health. A study in 2013 found that mercury found in the fish in the Pacific Ocean could be linked to coal-fired plants in Asia.[ citation needed]

Greenhouse gases[edit]
Main article: Greenhouse gas

Combustion of coal —a sedimentary rock composed primarily of carbon— produces carbon dioxide. According to the United Nations Intergovernmental Panel on Climate Change, the burning of coal, a fossil fuel, is a significant contributor to global warming. (See the UN IPCC Fourth Assessment Report). Burning 1 ton of coal produces 2.86 tons of carbon dioxide.

Carbon sequestration technology, to remove significant quantities of carbon dioxide from the air, 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.[ citation needed] Carbon capture and storage is applied at large-point emitters of carbon dioxide to prevent it from entering the atmosphere.

As a quarter of world energy consumption in 2019 was from coal, reaching the carbon dioxide reduction targets of the Paris Agreement will require modifications to how coal is used.

Clean Coal and the Environment [edit]
Further information: Health and environmental impact of the coal industry

In conjunction with enhanced oil recovery and other applications, commercial-scale CCS is currently being tested in the U.S. and other countries.[ by whom?] 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 water sources such as oceans and aquifers used for drinking water supplies. As of 2021, the only demonstrator for CCS on a coal plant that stores the gas underground is part of the Boundary Dam Power Station.

The Great Plains Synfuels plant supports 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. A drawback of the carbon sequestration process is that it is expensive compared to traditional processes.