Sources of sulfur emissions

Tn the last several years, much of the work in sulfur oxide emission - control has been aimed at emissions from power plant stacks. However, there are many other stationary sources of sulfur emissions including non-ferrous smelters, sulfuric acid plants, and petroleum refineries. The papers in this collection are concerned with these other sources of sulfur-bearing off-gases. This volume is intended to be a consolidated reference source for those interested in the latest sulfur recovery methods. 

Can the sources of sulfur emissions described above account for all the sulfur observed to be deposited That is, does "what goes up" equal "what comes down" The answer is yeii The fate... 

The third major source of sulfur is pyrite and related sulfide minerals. The ore is roasted to secure SO2 gas which is then usually used directly for the manufacture of H2SO4 (p. 708). Again air pollution by vS02 gas emissions has been the subject of increasing legislation and control during the past three decades (p. 698). 

Emissions from sinter plants are generated from raw material handling, windbox exhaust, sinter discharge (associated sinter crushers and hot screens), and from the cooler and cold screen. The primary source of particulate emissions, mainly irons oxides, magnesium oxide, sulfur oxides, carbonaceous compounds, aliphatic hydrocarbons, and chlorides, are due to the windbox exhaust. Contaminants such as fluorides, ammonia, and arsenic may also be present. At the discharge end,... 

Power boilers at pulp and paper mills are sources of particulate emissions, S02, and NOx. Pollutants emitted from chemical recovery boilers include S02 and total reduced sulfur compounds (TRS). 

Before considering treatment of sulfur emissions to atmosphere, their minimization at source should be considered. Sulfur emissions can be minimized at source through ... 

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. 

The numerous process heaters used in refineries to heat process streams or to generate steam (boilers) for heating or steam stripping can be potential sources of sulfur oxides (SO2, and SO3), nitrogen oxides (NO and NO2), carbon monoxide (CO), particulates, and hydrocarbons emissions. When operating properly and when burning cleaner fuels such as refinery fuel gas, fuel oil, or natural gas, these emissions are relatively low. If, however, combustion is not complete, or heaters are fired with refinery fuel pitch or residuals, emissions can be significant. 

The main source of S emissions from riceflelds is the burning of crop residues, during which most of the sulfur in the residnes is converted to volatile oxides (Fox... 

Specifically, rapid urbanization, with the associated growth in industry and transportation systems, has increased regional concerns with regard to emissions of sulfur dioxide and nitrogen oxides. According to estimations for the year 2000, sulfur dioxide emissions in Asia surpassed the emissions of North America and Europe combined. The primary manmade source of sulfur and nitrogen in the Asia-Pacific region is fossil fuel combustion in... 

Since 1970, in OECD countries the problem of air quality has become the subject of studies at many scientific centers. Oil from the Middle East became the main source of energy. The content of sulfur in oil constitutes 2.5%-3%. In 1985 some European countries signed the CLRTAP protocol on a 30% reduction of sulfur emissions. As a result, present day levels of S02 emissions have decreased by more than 50% compared with 1980. Of course, this was possibly largely due to Europe going over to the use of Russian gas. 

Emission Rate Algorithms. In order to compile a natural emissions inventory, emission rate functions must be determined for the sources included in the inventory. The emission rate for a specific source will vary depending upon certain environmental conditions. Analyses of sulfur emission measurements collected by Adams et al. (2) and later studies (21.22) suggest that temperature plays an important role in determining sulfur flux. While the mechanisms controlling the release of natural sulfur emissions are not well understood, field observations have demonstrated characteristic trends in temperature-flux patterns. Sulfur emissions tend to increase logarithmically with increasing temperature for normal ambient temperatures (10°C to 35°C). 

The low emission rates measured in this study indicate that salt marshes are a minor source of sulfur to the global atmosphere. Furthermore, our measurement of deposition rates show the potential for losses to the same soil surfaces at times of elevated atmospheric concentration. 

Sulfuric acid is manufactured from elemental sulfur. Alining was the main source for this element, which was obtained from sulfide-containing ores, or in very pure form from underground deposits by the Frasch process (injection of superheated steam and air into drillings and the separation of the mixture that rises to the surface). The large-scale consumption of petroleum and natural gas has changed this scenario since sulfur occurs as an impurity in most fossil fuels and must be removed before the fuels are processed. These fuels are presently the main source of sulfur, and their relative importance tends to increase with more rigorous controls on emissions. 

Examination of the spatia-J. variation in the concentrations of excess S04, As, and H+ reveals an area of influence of some source of sulfur and arsenic on rainwater composition immediately to the northeast (downwind) of Tacoma,WA. Since the Tacoma smelter is the major emission... 

Power plants and refineries are the primary fixed sources of pollutant emissions in most urban areas. However, other industrial sources, distributed throughout the area, also emit substantial amounts of contaminants. Also during the winter months effluents from home heating can add significantly to the pollutant load in the atmosphere. Sulfur dioxide and particulates are emitted from nearly all fixed sources although many of the particulate emissions are controlled by the use of abatement devices and sulfur dioxide by the use of low sulfur fuels. Also, power plants emit large amounts of nitrogen oxides, and refineries, hydrocarbons. 

Fumaroles represent a gentler and more continuous source of sulfur. The sources can be dispersed and quite small, so the total emissions from this source are not easy to estimate. Some of them are dominated by H2S. The sulfur gases, SO2, H2S, Sg, have been found in a range of fumaroles (Montegrossi et al., 2001). Although present Sg remains a minor component several orders of magnitude below SO2 and H2S. The production of sulfuric acid through aerial oxidation of sulfur(IV) is the most familiar process but it can readily be produced by disproportionation in fumarolic systems (Kusakabe et al, 2000) ... 

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