Coal is the dirtiest of all fuels. In fact, coal plants are the single largest source of global warming pollution. A typical coal plant (600 MW) generates about 3.5 million tons of CO2 per year depending on its size and efficiency. It burns about 2.15 million tons of coal a year. Higher thermal efficiency (37-42 per cent) of the plants using IGCC super or ultra-super critical technology will reduce emission to an extent. The efficiency of coal plant is still too low at below 42 per cent compared to up to about 65 per cent of natural gas (or LNG) plants.
It is said that the only way to eliminate/reduce CO2 is to capture it before leaving to atmosphere. After capturing it has to be stored permanently or sequestered. Commercially viable capture and sequestration systems are yet to be in place even in the USA except for some pilot projects. We can hardly expect that Bangladesh's contemplated coal-fired power plants will install such facilities.
GLOBAL WARMING: Coal-burning power plants speed up global warming by filling the atmosphere with vast amounts of carbon dioxide. Coal burning leads to acid rain and smog, and emits more than 60 different hazardous air pollutants, such as a variety of toxic metals, organic compounds, acid gases, sulphur and, nitrogen, in addition to carbon dioxide and particulate matters.
Some emissions can be significantly reduced with readily available pollution controls, but most U.S. coal plants also have not installed these technologies.
MERCURY POLLUTION: Coal-fired power plants are the single largest source of mercury pollution. Every four tons of coal burnt produce one ton of coal ash. Waste created by a typical 500-megawatt coal plant includes more than 125,000 tons of ash and 193,000 tons of sludge a year. Toxic substances in the waste -- including arsenic, mercury, chromium, and cadmium -- can contaminate drinking water supplies, and damage vital human organs and the nervous system. One study found that one out of every 100 children who drink groundwater contaminated with arsenic from coal power plant waste is at risk of developing cancer. Contaminants enter the food chain or are scattered by the winds far and wide. Arsenic contamination of underground water in our northern districts of Bangladesh may be attributed to coal-fired power plants in Indian side around the region.
 Coal ash can spread over an area spanning up to 150,000 square kilometers (60,000 square miles). A single 100 megawatt (MW) coal-fired power plant emits approximately 25 pounds of mercury a year and 50 per cent of the mercury emitted can travel up to 600 miles from the power plant.
SULFUR DIOXIDE (SO2): Coal is a chemically complex fuel. Whenever it is burned, gases and particles of ash, called "fly ash," are released. The sulfur in coal combines with oxygen to form sulfur dioxide, which can be a major source of air pollution if emitted in large enough quantities.
Coal plants are the United States' leading source of SO2 pollution, which takes a major toll on public health, by contributing to the formation of small acidic particulates that can penetrate into human lungs and be absorbed by the bloodstream. SO2 also causes acid rain, which damages crops, forests, and soils, and acidifies lakes and streams. A typical uncontrolled coal plant emits 14,100 tons of SO2 per year. A typical coal plant with emissions controls, including flue gas desulphurization, emits 7,000 tons of SO2 per year.
NITROGEN OXIDES (NOX): NOx pollution causes ground level ozone, or smog, which can burn lung tissue, exacerbate asthma, and make people more susceptible to chronic respiratory diseases. A typical uncontrolled coal plant emits 10,300 tons of NOx per year. A typical coal plant with emissions controls, including selective catalytic reduction technology, emits 3,300 tons of NOx per year.
PARTICULATE MATTER: Particulate matter (also referred to as soot or fly ash) can cause chronic bronchitis, aggravated asthma, and premature death, as well as haze obstructing visibility. A typical uncontrolled plant emits 500 tons of small airborne particles each year. Baghouses installed inside coal plant smokestacks can capture as much as 99 per cent of the particulates.
MERCURY (HG): Mercury is classified into inorganic, organic and metallic mercury, which is a type of inorganic mercury. The methyl mercury, a type of organic mercury, is water-soluble. Most of oxidized Hg and all of the elemental Hg are carried away by wind. A small amount of the oxidized Hg ends up in water and may be formed into an organic form called Methylmercury, which type of Hg is concentrated in fish and birds. Mercury is one of the most harmful pollutants faced by fish and wildlife. Toxic mercury is released from coal-burning power plants and accumulates in rivers, lakes, water bodies and forests.
The US National Wildlife Federation (NWF), reports that as little as 0.002 pounds or 1/70th teaspoon of mercury a year can contaminate a 25-acre lake to the point where fish are unsafe to eat.
A typical uncontrolled coal plant emits approximately 170 pounds of mercury each year. Activated carbon injection technology can reduce mercury emissions by up to 90 per cent when combined with baghouses. This technology is currently found in just 8.0 per cent of the U.S. coal plants.
METHYLMERCURY (MEHG): MEHG contamination in food sources as low as one part per million (ppm) has been shown to cause death in some animals. U.S. states have issued fish consumption advisories due to high mercury concentrations in freshwater bodies throughout the country. According to the American Lung Association, 24,000 people die prematurely, 38,000 suffer heart attacks, 12,000 need hospital admissions and an additional 550,000 suffer asthma attacks every year, because of pollution from coal-fired power plants.
Harmful substances have been detected in milk cows. Mercury in mothers' blood and breast milk can interfere with the development of babies' brains and neurological systems and can lead to learning disabilities, attention deficit disorder, problems with coordination, lowered IQ and even mental retardation.
Other harmful pollutants emitted annually from a typical, uncontrolled coal plant include:
l 114 pounds of lead, four pounds of cadmium, other toxic heavy metals, and trace amounts of uranium. Baghouses can reduce heavy metal emissions by up to 90 per cent.
l 720 tons of carbon monoxide, which causes headaches and places additional stress on people with heart disease.
l 220 tons of hydrocarbons, volatile organic compounds (VOC), which form ozone.
l 225 pounds of arsenic, which will cause cancer in one out of 100 people who drink water containing 50 parts per billion.
l A 1,000 MW coal-burning power plant could have an uncontrolled release of as much as 5.2 metric tons per year of uranium (containing 74 pounds (34 kg) of uranium-235) and 12.8 metric tons per year of thorium.
In view of the long-term danger to natural endowment and public health, no coal-fired power plant in Rampal, Matarbari, Moheshkhali, Payra or any other place in Bangladesh can be justified.
Even if there are agreements with any country, wrongly entered into, we can cancel them and switch over to gas or other non-polluting energy source before it is too late.
Coal ash can spread over an area spanning up to 150,000 square kilometers (60,000 square miles). A single 100 megawatt (MW) coal-fired power plant emits approximately 25 pounds of mercury a year and 50 per cent of the mercury emitted can travel up to 600 miles from the power plant.
So the argument that Rampal is 25 km way from Sundarbans and chimney height is 275m can not justify construction of the proposed coal-fired power plant not only at Rampal but also in any other place in our country with monsoon climate having wind flow from south and North.
   In view of the long-term danger to natural endowment and public health, no coal-fired power plant in Rampal, Matarbari, Moheshkhali, Payra or any other place in Bangladesh can be justified and should not be imposed on the people. Even if there are agreements with any country, wrongly entered into, we can cancel them and switch over to gas or other non-polluting energy source before it is too late.
Dr Mustafizur Rahman is chairman, Institute of Development Strategy, Dhaka. The views expressed here are of the author's own and not necessarily of the organization he represents.
 idsrahman@msn.com
Adopting non-polluting energy source before it is too late
Mustafizur Rahman concluding his two-part article on coal-fired power plants | Published: August 25, 2016 00:00:00 | Updated: February 01, 2018 00:00:00
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