Sulfur dioxide coal burning

Petroleum is also versatile. It contains all the commercially important hydrocarbons, such as those that make up gasoline, diesel fuel, jet fuel, motor oil, heating oil, tar, and even natural gas. Using fractional distillation (Section 12.1), oil refineries can convert one type of petroleum hydrocarbon to another, thereby tailoring their output to fit consumer demand. Furthermore, petroleum contains much less sulfur than does coal and so produces less sulfur dioxide when burned. So, despite its vast coal reserves, the United States has a royal thirst for petroleum, the king of fossil fuels, consuming about 20 million barrels each day. This is about 11 liters per U.S. citizen per day. 

The annual production of sulfur dioxide from burning coal and fossil fuels, auto exhaust, and other sources is about 26 million tons. The equation for the reaction is... 

An industrial atmosphere is characterized by pollution composed mainly of sulfur compoimds such as sulfur dioxide (SO ), a precursor to acid rain, and nitrogen oxides (NO ), the backbone of smog in modern dties. Sulfur dioxide from burning coal or other fossil fuels is picked up by moisture on dust particles as sulfurous add. This is oxidized by some catalytic process on the dust particles to sulfuric acid, which settles in microscopic droplets and fall as acid rain on exposed surfaces. The result is that contaminants in an industrial atmosphere, plus dew or fog, produce a highly corrosive, wet, acid film on exposed surfaces. 

Sulfur Dioxide Emissions and Control. A substantial part of the sulfur dioxide in the atmosphere is the result of burning sulfur-containing fuel, notably coal, and smelting sulfide ores. Methods for controlling sulfur dioxide emissions have been reviewed (312—314) (see also Air POLLUTION CONTROL PffiTHODS COAL CONVERSION PROCESSES, CLEANING AND DESULFURIZATION EXHAUST CONTROL, INDUSTRIAL SULFURREMOVAL AND RECOVERY). 

In magnesium casting, sulfur dioxide is employed as an inert blanketing gas. Another foundry appHcation is as a rapid curing catalyst for furfuryl resins in cores. Surprisingly, in view of the many efforts to remove sulfur dioxide from flue gases, there are situations where sulfur dioxide is deHberately introduced. In power plants burning low sulfur coal and where particulate stack emissions are a problem, a controUed amount of sulfur dioxide injection improves particulate removal. 

The behavior of these pollution roses is intuitively plausible, because considerable hydrocarbon emissions come from motor vehicles which are operated in both winter and summer and travel throughout the urban area. On the other hand, sulfur dioxide is released largely from the burning of coal and fuel oil. Space heating emissions are high in winter and low in summer. The SO2 emissions in summer are probably due to only a few point sources, such as power plants, and result in low average concentrations from each direction as well as large directional variability. 

Consider coal burning in a boiler house. The assessor may not be able to measure the mass of sulfur dioxide (SOj) leaving the boiler stack, because of access problems and the lack of suitable sampling ports on the stack. The only information available is that the coal is of soft quality, containing 3% sulfur by weight and, on average, 1,000 kg of coal is burned each day. 

Fluidized bed combustion boilers are often conventional boilers but with unconventional, specially designed furnace beds. Fluidized bed combustion boilers are used to burn solid fuels, such as low-grade, high-sulfur crushed coal. The benefit of this process is its ability to provide 95 to 100% combustion (depending on the reactivity of the fuel) combined with reduced emissions of sulfur dioxide (S02) and nitrogen oxides (NOx). 

Another key feature of sulfur chemistry is the Lewis acidity of sulfur dioxide. Sulfur dioxide is a common atmospheric pollutant that results from burning coal to produce electricity. Most coal reserves in North America include significant amounts of sulfur-containing impurities. When coal is burned, sulfur combines with O2 to form SO2, a hard Lewis acid. 

Sulfur dioxide also exists in Earth s atmosphere. It is released by the burning of fossil fuels, such as coal and gasoline, in power plants and automobiles. Once in the atmosphere, the sulfur dioxide... 

Acid rain is actually a catchall phrase for any kind of acidic precipitation, including snow, sleet, mist, and fog. Acid rain begins when water comes into contact with sulfur and nitrogen oxides in the atmosphere. These oxides can come from natural sources such as volcanic emissions or decaying plants. But there are man-made sources as well, such as power plant and automobile emissions. In the United States, two-thirds of all the sulfur dioxide and one-fourth of the nitrogen oxides in the atmosphere are produced by coal-burning power plants. 

Sulfur Dioxide. Sulfur dioxide and nitrogen oxides, which are produced in modern society when coal, gas, and oil are burned in cars, power plants, and factories, react with water vapor in the air to form acids that negatively affect organic materials and even metals and stone when dissolved in airborne rainwater, the oxides of sulfur and nitrogen are the main cause of the formation of acid rain (see below). 

Acid rain is caused primarily by sulfur dioxide emissions from burning fossil fuels such as coal, oil, and natural gas. Sulfur is an impurity in these fuels for example, coal typically contains 2-3% by weight sulfur.1M Other sources of sulfur include the industrial smelting of metal sulfide ores to produce the elemental metal and, in some parts of the world, volcanic eruptions. When fossils fuels are burned, sulfur is oxidized to sulfur dioxide (SO2) and trace amounts of sulfur trioxide (SC>3)J21 The release of sulfur dioxide and sulfur trioxide emissions to the atmosphere is the major source of acid rain. These gases combine with oxygen and water vapor to form a fine mist of sulfuric acid that settles on land, on vegetation, and in the ocean. 

When coal, oil, and gas are burned for energy in power plants and in industries, sulfur dioxide is produced. Sulfur dioxide combines with water in the atmosphere to produce sulfurous acid (H2SO3). Subsequent oxidation in the presence of oxygen (air) yields sulfuric acid (H2SO4). 

Small amounts of some contaminants can be serious. When we burn coal, not only do we produce carbon dioxide, the major product, but we can liberate small amounts of mercury and larger amounts of sulfur dioxide. The mercury can form toxins that harm fish as well as humans, while sulfur dioxide can produce acid rain that destroys forests and water supplies. How can these contaminants be most effectively removed or dealt with And how can we generate the energy that we need without releasing such by-products ... 

Sulfur dioxide is released during the burning of sulfur-containing coal. Much of that gas is now removed from the effluent and used in the production of sulfuric acid. The dioxides of Se and Te are recovered from the residue after the elements have reacted with concentrated HN03. 

Fluidized bed combustion is a newer technology that burns coal in an efficient manner and can produce both electricity and heat. A mixture of finely crushed coal and limestone rides on a stream of air, which allows the coal to be burned at temperatures lower than conventional coal burners. This reduces the nitrogen oxide produced. The limestone absorbs sulfur from the coal, which reduces the sulfur dioxide. 

Sulfurous acid (H SOj) can be produced by burning sulfur to form sulfur dioxide (SOj) gas and by then dissolving the gas in water to form sulfurous acid. This is the acid produced by burning coal that has a high sulfur content the gaseous sulfur dioxide by-product of combustion then combines with atmospheric water to form acid rain. ... 

A growing use of lime is in pollution control, where lime scrubbers placed in combustion stacks remove sulfur dioxide present in combustion gases from the burning of high sulfur coal. 

Sulfur dioxide is released during these operations when either coal or oil is burned. Coal and oil both naturally contain compounds of sulfur that, when burned, produce sulfur dioxide. The sulfur content of both coal and oil ranges from less than 1 percent to more than 7 percent, although refined petroleum tends to have lower concentrations of sulfur than do most forms of coal. Natural gas, by... 

The goal of beneficiation is to remove as much sulfur from a fuel as possible before it is ever burned. When burned, fuel with lower sulfur content will produce less sulfur dioxide. Beneficiation is usually accomplished by a physical process that separates one form of sulfur, pyritic sulfur, from coal. Pyritic sulfur consists of sulfur minerals (primarily sulfides) that are not chemically bonded to coal in any way. The name is taken from the most common form of mineral sulfur usually found in coal, pyrite, or iron sulfide (FeS2). 

The mechanisms by which acid rain forms and exerts its effects on the environment are now quite well understood. The primary culprit in this process is sulfur dioxide, produced when sulfur-containing coal is burned in power generating plants ... 

Oxides of sulfur (principally sulfur dioxide) are generated during the burning of fossil fuels, most notably coal, and are classified as reducing pollutants because of... 

---