Emissions measurement sulfur dioxide

Sulfur Dioxide EPA Method 6 is the reference method for determining emissions of sulfur dioxide (SO9) from stationary sources. As the gas goes through the sampling apparatus (see Fig. 25-33), the sulfuric acid mist and sulfur trioxide are removed, the SO9 is removed by a chemical reaction with a hydrogen peroxide solution, and, finally, the sample gas volume is measured. Upon completion of the rim, the sulfuric acid mist and sulfur trioxide are discarded, and the collected material containing the SO9 is recovered for analysis at the laboratory. The concentration of SO9 in the sample is determined by a titration method. 

The EPA Method 6 provides procedures for measuring sulfur dioxide emissions from stationary sources where the gas sample is extracted from the exhaust stack. Ammonia, water-soluble cations, and fluorides cause interferences with SOx measurements. Method 6A concerns sulfur dioxide, moisture, and carbon dioxide measurements from fossil fuel combustion sources by chemically separating the SO2 and CO2 components, where different reagent chemicals are used. Method 6C discusses the use of instrument analyzers to measure... 

Figure 3.10. Time series of predictions with the acidification model PnET-BGC of changes in stream chemistry at Hubbard Brook to changes in past and potential future emissions of sulfur dioxide and nitrogen oxides, including the 1990 Amendments of the Clean Air Act and moderate and aggressive emission control scenarios. Shown are model-predicted stream concentrations of sulfate, nitrate, acid neutralizing capacity, pH and dissolved inorganic aluminum, and soil percent base saturation. Measured values are indicated for comparison...

Total sulfur in air, most of which is sulfur dioxide, can be measured by burning the sample in a hydrogen-rich flame and measuring the blue chemiluminescent emission from sulfur atom combination to excited S2 (313). Concentrations of about 0.01 ppm can be detected. 

For sources having a large component of emissions from low-level sources, the simple Gifford-Hanna model given previously as Eq. (20-19), X = Cqju, works well, especially for long-term concentrations, such as annual ones. Using the derived coefficients of 225 for particulate matter and 50 for SO2, an analysis of residuals (measured minus estimated) of the dependent data sets (those used to determine the values of the coefficient C) of 29 cities for particulate matter and 20 cities for SOj and an independent data set of 15 cities for particulate matter is summarized in Table 20-1. For the dependent data sets, overestimates result. The standard deviations of the residuals and the mean absolute errors are about equal for particulates and sulfur dioxide. For the independent data set the mean residual shows... 

A difficulty that should not be overlooked is that airborne particulates are rarely homogeneous. They vary greatly in size and shape, and their chemical composition is determined by factors specific to the source and location of the emissions. The combined effects and interactions of various substances mixed with particulates have not yet been established (except for sulfur dioxide), but they are believed to be significant, especially where long-term exposure occurs. Measurement techniques and their reliability may vary across regions and countries, and so may other factors, such as diet, lifestyle, and physical fitness, that influence the human health effects of exposure to particulates. 

Implementation of cleaner production processes and pollution prevention measures can yield both economic and environmental benefits. The following production-related targets can be achieved by measures such as those described above. The numbers relate to the production processes before the addition of pollution control measures. In sulfuric acid plants that use the double-contact, double absorption process, emissions levels of 2 to 4 kilograms of sulfur dioxide... 

The sulfur dioxide analyzer based on the ultraviolet principle is a sensitive instrument. Its detection limit can be less than one ppbv (parts per billion by volume). When used in emission measurements, the sample gas IS normally diluted prior to the measurement using a diluting stack sampler. 

In Mexico City, several air quality parameters are measured continuously by an Automated Monitoring Network operated by the Under Secretariat of Ecology. Carbon monoxide, particulate matter, sulfur dioxide, nitrogen oxide, and ozone are the contaminants exceeding Air Quality Standards. Emissions produced by 2.7 million vehicles and 35,000 commercial and industrial outfits are not easily dispersed in a Valley located at 2240 m and surrounded by two mountain chains which hinder air circulation. An Integral Program, recently established to alleviate pollution, is briefly described. 

Many deleterious effects have been associated with photochemically polluted air ozone is deflnitely associated with respiratory problems, plant damage, and material damage PAN has deflnitely been associated with plant damage, and some other members of this class of chemical compounds have been associated with eye irritation the hydroxyl radical is considered to be an important factor in the conversion of gas-phase intermediates to end products, such as sulfur dioxide to particulate sulfate the particulate complex is responsible for haze formation and has also been associated with eye irritation and respiratory effects. The aldehydes have been associated with eye irritation. Ozone and PAN themselves do not cause eye irritation. For purposes of control, much more research is needed, in order to relate the laboratory data about the concentrations of these various materials that have significant effects to their formation in the atmosphere from emission and their atmospheric distribution. The lack of convenient measurement methods has hindered progress in gaining this understanding. 

The concentrations of sulfur dioxide both emitted into the air and measured at monitoring stations have decreased significantly over the past two decades. Emissions dropped from about 26.4 million short tons (24 million metric tons) annually in 1982 to about 17.6 million short tons (16 million metric tons) in 2001. The largest decrease during this period occurred between 1992 and 2001, when the amount of sulfur dioxide released annually dropped by about a quarter. The only area in which improvement did not occur was in emissions from transportation, which rose from about 770,000 tons (700,000 metric tons) in 1980 to about 2 million short tons (1.8 million metric tons) in 2000. 

The Texas Air Control Board was responsible for monitoring emissions of hydrogen sulfide and sulfur dioxide during all phases of the Sulphlex construction The measurements indicated that neither gas was present at levels near those which would pose a safety or environmental hazard during any phase of the operation. 

Sulfur Dioxide. Both flame photometric and pulsed fluorescence methods have been applied to the continuous measurement of S02 from aircraft. In the flame photometric detector (FPD), sulfur compounds are reduced in a hydrogen-rich flame to the S2 dimer. The emission resulting from the transition of the thermally excited dimer to its ground state at 394 nm is measured by using a narrow band-pass filter and a photomultiplier tube. 

The principal measure of the previously mentioned "allowances program (see Fig. I) is expressed in terms of tons of sulfur dioxide (SOs) emitted. However, close behind the environmental effects of SO) are emissions of nitric oxides (NOt). Unfortunately, the chemistry of SO> removal differs from that of NOr removal. 

An emissions test of the pyro-gas was conducted at Conrad on December 18, 1986, while pyrolyzing TDF. Measurements included particulate, metals, volatile and semi-volatile organic compounds, sulfur dioxide (S02), nitrogen oxides (NOx), carbon dioxide (C02), oxygen (02), and carbon monoxide (CO).1 The test results are presented in Table 8-3. Note that these emission estimates do not reflect atmospheric emissions. 

The oxides of sulfur are measured both in ambient air, where their concentration is usually a small fraction of one ppm, and in stacks and other industrial emissions, where their concentrations are in hundreds of ppm. As already discussed in Section 3.2.11, sulfur dioxide absorbs radiation over a broad range of wavelengths, which includes both the IR (Table 3.20) and UV regions. 

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