Sulfur dioxide pollution from

Bipolar membranes may be used to avoid the acid rain problem [11]. From 65 to 90% of the acid rain problem is due to sulfur-dioxide pollution from the smoke of power stations. A process was developed to sorb sulfur dioxide from flue gases by sodium sulfite solution. Sodium sulfite was converted to sodium... 

Air Pollution. Particulates and sulfur dioxide emissions from commercial oil shale operations would require proper control technology. Compliance monitoring carried out at the Unocal Parachute Creek Project for respirable particulates, oxides of nitrogen, and sulfur dioxide from 1986 to 1990 indicate a +99% reduction in sulfur emissions at the retort and shale oil upgrading faciUties. No violations for unauthorized air emissions were issued by the U.S. Environmental Protection Agency during this time (62). 

Turner, D. B., and Irwin, J. S., Comparison of sulfur dioxide estimates from the model RAM with St. Louis RAPS measurements, in "Air Pollution Modeling and Its Application 11" (C. de Wispelaere, ed.). Plenum, New York, 1982. 

Since this estimated share pattern was derived mainly from projection of trends (particularly long term trends), it seems appropriate to focus on oil and speculate as to how possible future events might alter its forecast future role. Events related to pollution control tend to indicate increases in petroleum demand. The use of lead free gasoline, for instance, requires additional refinery processing, which in turn consumes more petroleum fuel. Increasingly tighter controls on sulfur dioxide emissions from thermal-electric plants will cause a shift from coal to low sulfur fuel oil if there is no economic flue-gas desulfurization to cope with coals sulfur content. 

However, this reaction is very slow in the absence of a catalyst. One of the mysteries during early research on air pollution was how the sulfur dioxide produced from the combustion of sulfur-containing fuels is so rapidly converted to sulfur trioxide in the atmosphere. It is now known that dust and other particles can act as heterogeneous catalysts for this process (see Section 15.9). In the preparation of sulfur trioxide for the manufacture of sulfuric acid, either platinum metal or vanadium(V) oxide (V205) is used as a catalyst, and the reaction is carried out at approximately 500°C, even though this temperature decreases the value of the equilibrium constant for this exothermic reaction. 

Sulfurous acid. Sulfur dioxide (SO2) from the burning of high-sulfur coal forms sulfurous acid in contact with water. Oxidizing air pollutants, such as hydrogen peroxide, convert sulfurous acid to sulfuric acid ... 

There is, however, some success to note in the reduction of sulfur emissions from industrial operations in some developed countries. The European Union, for example, expect a decrease in sulfur dioxide emissions from 1990 to 2010, ranging from 11 to 47% in its individual member states (Anonymous 1999, see also Part I, Chapter 3). However, significant problems persist with regard to air pollution by SO2 (see the following paragraph). 

The problem of sulfur dioxide pollution is made more complicated by the energy crisis. As petroleum supplies dwindle and the price increases, our dependence on coal will probably grow. As supplies of low-sulfur coal are used up, high-sulfur coal will be utilized. One way to use high-sulfur coal without further harming the air quality is to remove the sulfur dioxide from the exhaust gas by means of a system called a scrubber before it is emitted from the power plant stack. A common method of scrubbing is to blow powdered limestone (CaC03) into the combustion chamber, where it is decomposed to lime and carbon dioxide ... 

However, this reaction is very slow in the absence of a catalyst. One of the mysteries during early research on air pollution was how the sulfur dioxide produced from the combustion of sulfur-containing fuels is so rapidly converted... 

Thus, it has become very apparent over the last three decades that abatement of air pollution needs to be mandatory now and in the future. Four main avenues of action are open to decrease the amount of sulfur dioxide emitted from stacks of power-generating plants (1) bum low-sulfur fuels, (2) desulfurize available fuels, (3) remove SOx from flue gases, or (4) generate power by nuclear reactors. 

As an example of how to balance a chemical equation, consider the reaction of hydrogen sulfide gas (H2S) with sulfur dioxide (SO2) to yield elemental sulfur (S) and water (H2O). This reaction is the basis of the Claus process by which commercially valuable elemental sulfur is recovered from pollutant sulfur dioxide and from toxic hydrogen sulfide in sour natural gas. The steps used in balancing the equation are the following ... 

The equation has excellent correlation with observed data, as shown by Fig. 2.17, which compares predicted and observed corrosion rates. This equation accounts for 92% of the variability of the corrosion rates R = 0.92). Thus, only the 8% residual variability cannot be explained by the equation. This formula should be used with caution, however. It was developed from corrosion rate data collected at sites with fairly high humidity and sulfur dioxide pollution levels. Thus, it predicts no corrosion when the... 

Hydrogen sulfide pollution from artificial sources is not as much of an overall air pollution problem as sulfur dioxide pollution. However, there have been several acute incidents of hydrogen sulfide emissions resulting in damage to human health and even fatalities. The most notorious such incident occurred in Poza Rica, Mexico, in 1950. Accidental release of hydrogen sulfide from a plant used for the recovery of sulfur from natural gas caused the reported deaths of 22 people and the hospitalization of over 300. 

Toxic or malodorous pollutants can be removed from industrial gas streams by reaction with hydrogen peroxide (174,175). Many Hquid-phase methods have been patented for the removal of NO gases (138,142,174,176—178), sulfur dioxide, reduced sulfur compounds, amines (154,171,172), and phenols (169). Other effluent treatments include the reduction of biological oxygen demand (BOD) and COD, color, odor (142,179,180), and chlorine concentration. 

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