The impact of fuel combustion on the environment, why is fossil fuel burning polluting the environme

China is a coal-rich, oil-poor, gas-rich country, with the rapid development of the economy, the contradiction between domestic oil supply and demand is becoming increasingly prominent, the dependence on imports is increasing year by year, net imports of 70 million tons in 2000, 80 million tons in 2001, net imports of oil in 2003 reached a record 97.79 million tons, accounting for more than 40% of China's total energy demand. However, China's total natural gas reserves are 38 trillion cubic meters and coal reserves are 114.5 billion tons. Therefore, the promotion and application of clean alternative fuels as a supplement to petroleum resources has been of great strategic significance to China.

As far as vehicle fuels are concerned, there are currently five main types of international and domestic vehicle clean fuels: liquefied petroleum gas, natural gas, methanol gasoline, ethanol gasoline, and dimethyl ether. Each of them has its own characteristics and advantages and disadvantages, but in the final analysis, we should and need to know who is the subject of the current development, who is the trend of future development and how it will be used, and which existing enterprises are running such projects.

The following is elaborated and analyzed from six aspects: the basic introduction of fuel, advantages and disadvantages, use effect, development, operation of enterprises, and economic analysis

1. Liquefied petroleum gas.

Liquefied petroleum gas (LPG) is a mixture of hydrocarbons (such as propane, propylene, butane, butylene) with three or four carbon atoms, which is non-toxic, colorless and odorless at room temperature and pressure, and has the advantages of high octane number, good anti-knock performance, high calorific value, low storage and transportation pressure, etc., and is a substitute fuel for automobiles with excellent performance.

The pollution of burning coal is greater, the sulfur content of general coal is about 2% (mass fraction), and the sulfur content after coal washing is also greater than 1%, and sulfur will form SO2 after combustion, which is quite serious to the air pollution. In addition, coal burning also has the problem of dust pollution.

(1) Combustion of coal.

Because coal contains a small amount of sulfur, nitrogen and other elements, sulfur dioxide (SO2) is emitted when burned

Nitrogen dioxide (NO2

and other pollutants, they will form acid rain when dissolved in water Acid rain not only affects human health and plant growth, but also causes damage to natural resources and buildings If coal is not fully burned, it will also produce the toxic gas carbon monoxide (CO) to pollute the air Therefore, the use of raw coal as fuel should be minimized

2) Combustion of fuel for automobiles.

The fuel used in automobiles is gasoline or diesel They will produce carbon monoxide, nitrogen oxides and unburned hydrocarbons, lead-containing compounds, soot, etc., collectively known as exhaust gases Discharged into the air, it will cause air pollution and damage to human health

Answer: Sulfur dioxide (SO2) is emitted when coal is burned

Nitrogen dioxide (NO2

and other pollutants, they will form acid rain when dissolved in water, and if coal is not fully burned, it will also produce the toxic gas carbon monoxide (CO) to pollute the air

The fuel used in automobiles is gasoline or diesel They are burned to produce carbon monoxide, nitrogen oxides and unburned hydrocarbons, lead-containing compounds, soot, etc., collectively known as exhaust gases Discharged into the air, it will cause air pollution

Since fossil fuels are the main part of the world's primary energy, they are extracted and burned in large quantities, so the impact on the environment is also a cause for concern.

The environmental impact of the mining process is most typically coal mining, which includes damage to land, damage to villages, and impacts on water resources. According to incomplete statistics, so far, an average of 20,000 hectares of farmland have collapsed per 10,000 tons of coal mined. More than 4.8 billion tons of coal are pressed under buildings in China, of which 2 3 are pressed under villages for coal.

Moreover, coal combustion pollutes the environment by producing sulfur dioxide and nitrogen dioxide.

In the plain areas of Shandong, Hebei, Henan, Anhui and Jiangsu provinces, there are 1,100 coal-pressing villages, with more than one million villagers living there. The pollution of water resources caused by mining has a large amount of impact on the ecological environment, with an average of 2 tons of sewage being discharged for every ton of raw coal mined, and what is more serious is that in some areas, due to the serious pollution of water sources and rivers, lakes and seas, there is a shortage of water for residents.

The impact of fossil fuels on the environment during the utilization process is mainly the pollution caused by various gases and solid wastes during combustion and waste heat during power generation. There are two main environmental impacts of pollutants produced by fossil fuels. The first is global climate change.

The carbon in the fuel is converted into carbon dioxide into the atmosphere, which increases the concentration of carbon dioxide in the atmosphere, which leads to the intensification of the greenhouse effect, changes the global climate, and imbalances the ecological balance. The second is thermal pollution. The "waste heat" left over from the power generation of thermal power plants is discharged into rivers, lakes, the atmosphere or oceans, causing thermal pollution in most cases.

For example, when this waste hot water enters the water, its temperature is on average 7 8 higher than the temperature of the water, causing organisms to leave the water.

Coal: The main element is carbon, with small amounts of cyanide, oxygen, phosphorus, nitrogen, and sulfur, which are responsible for the formation of acid rain.

What are the main pollutants produced by combustion (a).

a.Sulfur oxide SOX

b.Dust. and HC compounds.

Common pollutants in the combustion process are carbon monoxide, sulfur dioxide, nitrogen oxides and soot, and combustion also produces noise pollution, thermal pollution and lead pollution (see Vehicle Exhaust Pollution).

1. Carbon monoxide is mainly caused by incomplete combustion of carbon-containing fuels. It accounts for about 3% in boiler exhaust and up to 13% in car exhaust. For boilers and industrial furnaces, as long as the fuel is fully oxidized, secondary combustion may reduce the carbon monoxide content in the flue gas.

Reducing carbon monoxide in the exhaust of internal combustion engines is a more complex issue. The main measures are: improving the structure of internal combustion engine equipment, such as correctly designing the boost ratio, adding a catalytic refueling unit to the exhaust duct, and automatically adjusting the oil-gas ratio in operation.

2. Sulfur dioxide comes from sulfur, sulfate and organic sulfide in fuel. The volume concentration of sulfur dioxide in flue gas is and is sometimes reached. Since more than 90% of the sulfur in the processing is transferred to heavy oil, the sulfur content of heavy oil can reach 1 3%.

Effective measures to prevent sulfur dioxide pollution are: fuel desulfurization or flue gas desulfurization, and the use of low-sulfur fuel combustion is also the most commonly used method.

3. Nitrogen oxides include nitrogen dioxide and unstable nitric oxide, nitrous oxide and nitrogen tetroxide. At high temperatures (above 1650), they can be produced directly from nitride orange noises in fuel and nitrogen and oxygen in the air. The nitrogen oxide content in flue gas can reach 1200 mg m3 and in car exhaust up to 4000 mg m3.

Its content can be reduced by wet liquid absorption, dry solid adsorption or catalytic conversion methods; The use of lamellar combustion in gasoline engines is also a way to reduce the nitrogen oxide content.