After the Great World War , developed and industrial countries which knew the long-term problems of industrialization , began programming to avoid the related consequences .
The export of polluted technology of this countries as a gift which brought the developing countries face to face with environmental destruction effects caused the problem of destruction comprehensive .
In this aspect , considering air pollution and the resulted consequences have special significance .
The pollutants do not emit in the environment automatically . First, there should be a pollutant source to discharge them in the environment .
On this basis , air pollutants can be divided into 3 main categories :
In residential areas , the main reason of air pollution is the consumption of fossil fuels. In recent years the use of oil and gas ( especially in winter ) make pollutants disperse .
As a result of incomplete fuel consumption, the air pollution becomes aggravation and the calorific value of the fuel material decreases .
-The function of motor vehicles in air pollution
The emitted pollutants from motor vehicles result from 3 main sources of the car:
Exhaust , crankcase, evaporation from the fuel tank and carburetor . It is estimated that near the %55 hydrocarbons from the exhaust , %25 from the crankcase and %20 from gasoline tank and carburetor and all monoxide carbon and nitrogen oxides emit from the exhaust . According to a research , the amount of particles emitted from the crankcase is about one third up to half the amount of the particles emitted from the exhaust .
In gasoline motors of motor vehicles , the mixture of air and gasoline within the cylinder is exploded through a spark of the candlle and resulted gases made by fuel arrive the environment through the exhaust .
For complete combustion of one volume of gasoline , 15 volumes of air should be mixed with one volume of gasoline . In most of the cars, this relation is less than 15 to 1 . Consequently , burning is incomplete and a large amount of materials other than Anhydride carbonic and water emit from the cars exhaust which has a large share in cities air pollution .
The first effective parameter in the formation of mono oxide carbon and hydrocarbons is the relation of air to fuel in the motor .
The concentrations of these air pollutants while the relation of air to fuel decreases , increase .
Therefore, one of the consequences of less air is the formation of monoxide carbon instead of dioxide carbon , unburned gasoline and hydrocarbons .
The formation of nitrogen oxide is on unavoidable, because this material is obtained under the influence of fuel temperature and the amount of available oxygen for mixing with nitrogen .
Thus where intracombustion motors move , hydro carbons and nitrogen oxides are produced and these materials cause oxidized smog in the cities with shining sun .
The other factor in the amount of emitted pollutants (monoxide carbon and hydro carbons) is the speed of motor vehicles . The amount of emitted hydro carbons and monoxide carbon decrease with the increase of car speed , while nitrogen oxides are not subject to average speed of cars .
Lead particles , smut and motor oil are also emitted from the exhaust .
The emission of sulphur oxide From the motor exhaust depends on the amount of sulphur existed in gasoline . As the average quantity of sulphur of gasoline is low , sulphur oxides are not usually the main pollutants in gasoline motors .
There are three pollutant sources in the car other than exhaust :
The most important of them is crankcase which has put it in its place . The current air in the moving car enters crankcase . The air enters a canal and emits from crankcase ( Depending on the speed of the car ) . About %20-40 of emitted hydrocarbons are transferred to the air through the crankcase .
The emissions of crankcase are called lateral gases . which together with the emissions of the exhaust form almost all pollutin caused by gasoline cars .
In diesel motors gas oil and air do not mix before entering the cylinder . Then the air is condensed and fuel material in the form of spray enters the warm air and sparks .
The power obtained from the diesel motors is controlled through injected fuel material for each cycle . Such motors have the same problems as those of gasoline ones except for that firstly air enters the motor without control hatch therefor in diesel motors the relation of air to fuel is more than the gasoline motors . Secondly, fuel material is injected directly into combustion case and there is no need to carburator and the combustion is done by the heating based on the pressure of fuel and air mixture.
Meanwhile , the emission of monoxide carbon and hydro carbons occures in a relatively little amount .
Because emitted hydrocarbons from the exhaust of diesel motors are maily related to the unburned gas oil , so their emission depends on the sprayed fuel material volume into the combustion case .
The high temperature and extra oxygen avaiable in the case of diesel fuel cause emission of large amount of nitrogen oxide .
Industrial units pollute the air in two ways:
Production process in industrial and production units is another pollutant factor . Industrial units due to the kind of product use different sorts of preliminary materials that in different forms ( firstly or secondary pollutant ) can enter the environment along the production process .
Every industrial or production unit can not be called pollutant , but usually the unsuitable location of unit and also not using the air pollution control techniques causes air pollution .
The increase of population is one of the most effective agents of intensification of environment pollutions .
With the extension of cities and setting several factories , much poisons release in the air . In addition to the factories , cars in the cities are also considered as air pollutants . The chimneys of houses and public places are also play effective part in air pollution . Today, even pollution threatens plains and fields .
3.1 Energy Consumption Statistics
|
|
(Mtoe) |
% |
% |
% |
% |
% |
| 1967 |
|
|
|
|
|
|
| 1970 |
|
|
|
|
|
|
| 1980 |
|
|
|
|
|
|
| 1989 |
|
|
|
|
|
|
| 1990 |
|
|
|
|
|
|
| 1991 |
|
|
|
|
|
|
| 1992 |
|
|
|
|
|
|
| 1993 |
|
|
|
|
|
|
| 1994 |
|
|
|
|
|
|
| 1995 |
|
|
|
|
|
|
| 1996 |
|
|
|
|
|
|
| 1997 |
|
|
|
|
|
|
| Sector | Energy consumption |
| (mtoe) | |
| 1 Industry |
|
| 3 Domestic |
|
| 4 Power generation |
|
| 5 Fuel conversion |
|
B. Mobile sources
| Vehicle category | Energy consumption (Mtoe) |
| LPG vehicles |
|
| Motor cycles- 2 stroke |
|
| Motor cycles- 4 stroke |
|
| Gasoline cars (<1.51) |
|
| Gasoline cars (1.5-2.01) | |
| Gasoline cars & light trucks(>2.01) |
|
| Heavy trucks-gasoline |
|
| Buses (gasoline) |
|
| Diesel cars (<1.51) |
|
| Diesel cars (1.51-2.01) |
|
| Diesel cars & light trucks (>2.01) |
|
| Heavy trucks (diesel) |
|
| Buses (diesel) |
|
| Trains (coal) |
|
| Trains (diesel) |
|
| Boats/ships (diesel) |
|
| Boats/ships (fuel oil) |
|
| Light truck (3.5 Tons) |
|
| Heavy truck (10 Tons) |
|
Source: Balance sheet of energy
In nature it is found in the form of free or mixed with other elements. Sulfur is one of the impurity unchangeable in coal and heavy oils and takes part in combustion .
The available sulfur in fuels , is mixed with air oxygen when combustion is carried out and produces sulfur oxides . ( In from of gas )
Most of these oxides are produced from combustion of sulfuric materials , chemical factories , household resource , traffic vehicles , small workshops and from burning of rubbish .
The best sulfur oxide which is produced in combustion is called sulfur dioxide ( So2 ) .
This gas is heavier than air and has an unpleasant and piercing odour and colorless and mixes with water vapour and produces sulfuro acid . This acid is a colorless liquid and is a little corroding .
In industry is used as a bleaching material , but in the air acts as pollutant and causes yellow spots on the body of the car . These acid is easily mixed with air oxygen and produces sulfuric acid which is very corroding .
This acid is also produced in other way . Thus sulfur dioxide is mixed with oxygen and produces sulfuric anhydride .
This gas changes into colorless liquid in the air with white solid particles . Sulfur oxide which comes out from factory chimney is emitted quickly and becomes oxidized slowly .
The resultent sulfuric anhydride mixes with water quickly and produces dangerous sulfuric acid . sulfur oxides make leaves of the trees yellow and corrods marble and decays iron and steel .
The oxides weaknesses sight and prevents the sun radiation to the rarth .
Sulfur oxides affect on human breath organs as much so that in high condenses gas S02 causes scratching and irritation the upper parts of the lung and in low condenses together with dust particles damaged the respiratory cells .
3.2.1 Sources
| Process | Product Throughput (Ton/year) |
| Paper & pulp |
|
| Copper smelting in Zanjan |
|
| Lead smelting in Zanjan |
|
| Zinc smelting |
|
| Oil refineries |
|
| Sulphuric acid production |
|
| Sarcheshmeh copper in Kerman |
|
| Sub-region of country (eg.State province etc.) | Type of coal | Sulphor
Contents (%) |
Reference |
| Sub-region 1 | Coking coal |
|
|
| Total of country | Other bituminous coal & Anthracite |
|
|
| Sub-Bituminous coal |
|
||
| Lignite |
|
||
| Derived coal (coke) |
|
||
| Derived coal (patent fuel) |
|
||
| Derived coal (brown coal briquettes) |
|
Source: Balance sheet of energy
| Sub-region of (eg.State, province) | Type of oil | Sulphur
Contents (%) |
Reference |
| Crude Oil | 1-1.74 %W | ||
| Gasoline (motor. Aviation & jet) | Max 1 // | ||
| Kerosene | Max 0.12 // | ||
| Diesel Oil | Max 1 // | ||
| Heavy Fuel Oil | Max 2 // |
| Process | Emission factor
(S per tonne product) |
Reference |
| Paper & pulp | ||
| Copper smelting | ||
| Lead smelting | ||
| Zince smelting | ||
| Oil refineries | ||
| Sulphuric acid production |
Note: In this case, information is not available.
3.2.3 Current sulphur emission estimates
A. Sectoral breakdown of emissions
| Sector | Emission (tonnes S/yr) 1996 |
| 1 Industry |
|
| 2 Transport |
|
| 3 Domestic |
|
| 4 Power generation |
|
| 5 Fuel conversion |
|
| Source type | Emission (000 tonnes S/yr) |
| 1 Point source |
|
| 2 Area source |
|
B. Distribution of emissions
| Region | Total emission (tonnes So2/y) | Area source | Point source |
|
|
|
Shazan-Suburbof Arak | Refinery |
|
|
|
|
Petrochemistry |
|
|
|
Tabriz Province | Refinery |
|
|
|
Esfahan P. | Steel mill |
|
|
|
|
Ghatran Refinery |
|
|
|
|
Mobarakeh Steel Complex |
|
|
|
|
Amin Steel Pieces Group |
|
|
|
|
Iranian Poly Acril Company |
|
|
|
|
Iranian Refractory Products Co. |
|
|
|
|
Petrochemistry |
|
|
|
|
Refinery |
|
|
|
Fars Province | // |
|
|
|
|
Petrochemistry |
|
|
|
|
Dena rubber manufacture |
|
|
|
Khoozestan Province | Petrochemistry |
|
|
|
|
Razi Petrochemistry |
|
|
|
|
Refinery |
|
|
|
Zanjan Province | Copper smelting industries |
|
|
|
Khoozestan Province | Farabi Petrochemistry |
|
|
|
Tehran Province | Refinery |
|
|
|
Kerman Province | Sarcheshmeh Copper Complex |
|
|
|
|
Shahid Firoozi power station |
|
|
|
|
Besat power station |
|
|
|
|
Shahid Montazer-e- /Ghoam power station |
|
|
|
|
Eslam Abad power station |
|
|
|
|
Shahid Mohammad Montazeri power station |
|
|
|
|
Shahid Beheshti-e-loushan power station |
|
|
|
|
Shahid Salimi power station |
|
|
|
|
Ramin power station |
|
|
|
|
Shahid Madhaj power station |
|
|
|
|
Bandar abas power station |
|
|
|
|
Zarand power station |
|
|
|
|
Tabriz power station |
|
|
|
|
Shahid Rajaee power station |
|
|
|
|
Bistoon power station |
|
|
|
|
Hamedan power station |
|
|
|
|
Mashad power station |
|
|
|
|
Toos power station |
| Year | Emission (tones S/yr) |
| 1980 |
|
| 1985 |
|
| 1990 |
|
| 1991 |
|
| 1992 |
|
| 1993 |
|
| 1994 |
|
| 1995 |
|
| 1996 |
|
| 1997 |
|
| 1998 |
|
Nitrogen by itself is odourless and tasteless gas and forms %87 of the atmosphere . On contrary of nitrogen which is a fine gas , nitrogen oxides are dangerous for man . The number of nitrogen oxides is large but among them there are two important pollutants : Nitric oxide (No) , Nitrogen dioxide ( No2 ) . "No" gas is largely produced in car cylinders , heating power station and energy conversion .
In most of the cities , car is the only production source of "No" . This gas which comes from much heating , enters the cold exhaust at full speed and does not analysis into nitrogen and oxygen .
Part of the "No" gas that has the least hazards , revert to nitrogen dioxide in atmosphere that is hazardous . "No2" is formed simply in photochemical reactions and thus it is called one of the photochemical products .
The "No2" which is made in chemical fertilizer factories and caused by explosive materials are also enters to the atmosphere . Nitrogen dioxide which is one of the most important pollutants is brown and for this reason , weakens the sight in the cities . Besides , its sharp and unpleasant odour in condense 1-3 ppm can be observed .
"No2" gas effects the plants and prevents them from growing . It also
mixed with water vapour and produces nitric acid which is harmful to the
metals.
A. Mobile sources
| Vehicle Category | Number of vehicles |
| LPG vehicles |
|
| Motor cycles-2 Stroke |
|
| Motor cycles-4 Stoke | |
| Gasoline cars(<1.51) |
|
| Gasoline cars (1.51-2.01) | |
| Gasoline cars & light trucks (>2.01) |
|
| Heavy trucks-gasoline |
|
| Buses (gasoline) |
|
| Diesel cars(1.51) |
|
| Diesel Cars (1.51-2.01) |
|
| Diesel cars & light trucks (>1.51-2.01) |
|
| Diesel cars & light trucks (>2.01) |
|
| Heavy trucks (diesel) |
|
| Trains coal |
|
| Buses diesel |
|
| Trains diesel |
|
| Boats /ships (diesel) |
|
| Boats /ship (fuel oil) |
|
B. Industrial process emissions of Nox
| ProcessNox Emission
(thousand tonnes/yr) |
Emission Factor | |
| Mineral production |
|
Not available |
| Chemical industry |
|
|
| Metal production |
|
|
| Other production |
|
|
| Total industry |
|
|
| Transport |
|
Author: Dr. Abduli
Note: Information about the table 3.3.2 ( Emission Factors )
and the table B ( Mobile sources ) is not available.
| Sector | Emission (tonnes.No2 equivalent/yr) |
| 1 Industry |
|
| 2 Transport |
|
| 3 Domestic |
|
| 4 Power generation |
|
| 5 Fuel conversion |
|
| Source type | Emission (000 tonnes No2 equivalent/yr) |
| 1 Point source |
|
| 2 Area source |
|
3.3.4 Trends in emissions
| Year | Emission (tonnes No2 equivalent) |
| 1960 |
|
| 1970 |
|
| 1980 |
|
| 1988 |
|
| 1989 |
|
| 1990 |
|
| 1991 |
|
| 1992 |
|
| 1993 |
|
| 1994 |
|
| 1995 |
|
| 1996 |
|
| 1997 |
|
| 1998 |
3.4 Ammonia
Particles in the form liquid or solid with a diameter a little more than 0.0002 micron to 500 micron are among the most important pollutants of the air .
The time of the suspension of these particles in the air may last from a few second to several years .
Physically these particles have various properties and chemically have many various compounds and properties .
The dust emitted from the earth by wind and also the volcano ashes , salt secretion , viruses , bacteria , spores, vegetable groups can be called among the natural sources of air pollution . Since many years ago these substances have been available in the atmosphere before the appearance of the man . But human beings’ activities in some cases have increased their concentration in the air. The pollutant particles resulted from human society are usually produce and enter the air in 4 ways :
4-The material result from photo chemical reactions: Because of smog phenomenon , particles as large as 0.2-0.8 micron are formed in the air .
The available of these particles in the air is completely effective
in decreasing of the sight . In comparison , the poisonous effects of some
solid substances which are released to the air by factories and emitted
gases of the car , are more than other particles . Lead , Brilium , Asbestos
, Cadmium , Floures and Arsenic are among these of course other than the
compounds containing lead which exist through gasoline consumption , the
air pollution . For the sake of these substances is quantitative on the
whole , particles decrease the sight vision and leave unpleasant effects
in the environment .
| Sector | Emission (tonnes/year) | Percentage |
| Industry |
|
|
| Power generation |
|
|
| Biomass burning |
|
|
| Vehicular traffic |
|
|
| Natural Sources(eg.Soil dust) |
|
Source: Balance sheet of energy
3.5.3 Trends in emissions
| Year |
|
| 1960 |
|
| 1970 |
|
| 1980 |
|
| 1988 |
|
| 1989 |
|
| 1990 |
|
| 1991 |
|
| 1992 |
|
| 1993 |
|
| 1994 |
|
| 1995 |
|
| 1996 |
|
| 1997 |
|
| 1998 |