Combustion emissions

Combustion aids Combustion emissions Combustion technology Combustion turbines Comedos... 

Environmental considerations also were reflected in coal production and consumption statistics, including regional production patterns and economic sector utilization characteristics. Average coal sulfur content, as produced, declined from 2.3% in 1973 to 1.6% in 1980 and 1.3% in 1990. Coal ash content declined similarly, from 13.1% in 1973 to 11.1% in 1980 and 9.9% in 1990. These numbers clearly reflect a trend toward utilization of coal that produces less SO2 and less flyash to capture. Emissions from coal in the 1990s were 14 x 10 t /yr of SO2 and 450 x 10 t /yr of particulates generated by coal combustion at electric utiUties. The total coal combustion emissions from all sources were only slightly higher than the emissions from electric utiUty coal utilization (6). 

RCRA incinerator regulations include adrninistrative as weU as performance standards. Administrative standards include procedures for waste analysis, inspection of equipment, monitoring, and facihty security. Steps needed to meet adrninistrative standards are outlined ia the permit apphcation performance standards are demonstrated during a trial bum. Trial bum operating conditions are included in the permit to assure ongoing compliance with the performance standards. Performance standards include destmction and removal efficiency (DRE), particulate emissions limits, products of incomplete combustion emission limits, metal emission limits, and HCl and Cl emission limits (see Exhaust CONTROL, INDUSTRIAL). 

Products of Incomplete Combustion Emission Limits. Products of iacomplete combustion typically are not directly measured duting the trial bum. Instead, levels of carbon monoxide (qv) emissions are used as an iadication of combustion efficiency. High combustion efficiencies are assumed to result ia acceptable levels of products of incomplete combustion. If carbon monoxide emissions are measured at less than 100 ppmv dry basis, the standard is met. However, if emissions are greater than 100 ppmv, no more than 20 ppmv of total hydrocarbons (qv) are allowed at the iaciaerator stack duting the trial bum. 

In general, the environmental consequences resulting from emissions generated by the combustion of treated wood and the chemicals used to treat them are not well understood. Combustion of the materials involved in the incident unquestionably produced hazardous products of incomplete combustion emissions (e.g., dioxins and furans). 

The passage of the Clean Air Act Amendment (CAAA) on November 15, 1990, started a process for regulating the composition and quality of gasoline and diesel fuels sold in the United States. The CAAA s intent was to improve the nation s air quality by reducing ozone and other air pollutants. Title II of the CAAA requires the manufacture and sale of cleaner fuels in order to reduce evaporative and combustible emission of ... 

Diverse techniques have been employed to identify the sources of elements in atmospheric dust (and surface dust) (Table V). Some involve considering trends in concentration and others use various statistical methods. The degree of sophistication and detail obtained from the analyses increases from top left to bottom right of the Table. The sources identified as contributing the elements in rural and urban atmospheric dusts are detailed in Table VI. The principal sources are crustal material, soil, coal and oil combustion emissions, incinerated refuse emissions, motor vehicle emissions, marine spray, cement and concrete weathering, mining and metal working emissions. Many elements occur in more than one source, and they are classified in the... 

Emissions of NOj due to fossil fuel combustion emissions (Tg N/yr) Fertilizer production and usage (TgN/yr) ... 

Cooke M, Degner KB, Osborne MC, et al. 1984. Candidate sampling and analysis methods for twenty- one suspect carcinogens in combustion emissions. Proceedings-Air Pollution Control Association Annual Meeting, 77th 84-12.4. 

Polycyclic aromatic hydrocarbons (PAHs, sometimes also called polynuclear aromatics, PNA) are a hazardous class of widespread pollutants. The parent structures of the common PAHs are shown in Fig. 4 and the alkylated homologs are generally minor in combustion emissions. PAHs are produced by all natural combustion processes (e.g., wild fires) and from anthropogenic activity such as fossil fuels combustion, biomass burning, chemical manufacturing, petroleum refining, metallurgical processes, coal utilization, tar production, etc. [6,9,15,18, 20,24,131-139]. 

When epidemiological studies form the basis for the risk assessment of a single chemical or even complex mixtures, such as various combustion emissions, it may be stated that in those cases the effects of combined action of chemicals have been incorporated. Examples can, for instance, be found in the updated WHO Air Quality guidelines (WHO 2000). Thus, the guideline value for, e.g., ozone was derived from epidemiological studies of persons exposed to ozone as part of the total mixture of chemicals in polluted ambient air. In addition, the risk estimate for exposure to polycyclic aromatic hydrocarbons was derived from studies on coke-oven workers heavily exposed to benzo[fl]pyrene as a component of a mixture of PAH and possibly many other chemicals at the workplace. Therefore, in some instances the derivation of a tolerable intake for a single compound can be based on studies where the compound was part of a complex chemical mixture. 

Sources. B[major component of polynuclear aromatic hydrocarbons, also known as polycyclic aromatic hydrocarbons, and is usually bound to small particulate matter present in urban air, industrial and natural combustion emissions, and cigarette smoke. 

As we have seen, key nitroarenes found in extracts of ambient particulate matter are 1-nitropyrene (1-N02-Py), predominant in primary combustion emissions, and 2-nitrofluoranthene and 2-nitropyrene, major products of gas-phase atmospheric reactions. Here we focus simply on their atmospheric fates as particle-bound species participating in heterogeneous decay processes. Formation of such nitro-PAHs in gas-phase reactions is addressed in Section F. 

Lewtas, J., Combustion Emissions Characterization and Comparison of Their Mutagenic and Carcinogenic Activity, in Carcinogens and Mutagens in the Environment (H. F. Stich, Ed.), Vol. V, The Workplace Sources of Carcinogens, pp. 59-74, CRC Press, Boca Raton, FL, 1985a. 

Lofroth, G., Mutagenicity Assay of Combustion Emissions, Chemo-sphere, 7, 791-798 (1978). 

Mumford, J. L., C. T. Helmes, X. Lee, J. Seidenberg, and S. Nesnow, Mouse Skin Tumorigenicity Studies of Indoor Coal and Wood Combustion Emissions from Homes of Residents in Xuan Wei, China with High Lung Cancer Mortality, Carcinogenesis, 11, 397-403 (1990). 

In a house used for investigating indoor air pollution that had natural gas fueled applicances (a convective heater, a radiant heater, and a range with four burners), both the surface reaction of N02 and the direct combustion emissions contributed significantly to the measured indoor HONO. When an appliance was operational, the contribution of direct emissions was the more important source (Spicer et al., 1993). 

Emissions from fireplaces and stoves have been reported in several studies testing furnaces and wood fuel typical for different areas of the world. Wood smoke emissions typical for central Europe were investigated by Schmidl et al. [22, 23]. In these studies, different common European wood types were analysed to derive chemical profiles of wood combustion emissions for various types of wood. An overview of the fuel wood types used in the Alpine countries is given by Kistler et al. [24]. In the above-mentioned emission studies, wood has been burnt in a tiled wood stove [22] and in two automatically and two manually fired appliances [23]. The authors found a high variability for the emissions from small-scale manually fired wood combustion appliances in the performed individual tests. 

Finally the so-called mono- and macro-tracer approaches can be applied for determining source contributions. These methods rely on the fact that a number of chemical compounds can be directly linked to biomass combustion emissions. For example, ambient concentrations of water-soluble potassium, certain PAHs, anhydrosugars and many other tracers have been used as indicators for the impact of biomass burning. When the fractions of one of these tracers in PM and carbonaceous aerosols emitted by wood burning are known (emissions ratios), the contribution of wood burning at a receptor site can be calculated based on the concentration of the considered tracer (mono tracer method). 

Brandt C, Kunde R, Dobmeier B et al (2011) Ambient PM10 concentrations from wood combustion - emission modeling and dispersion calculation for the city area of Augsburg, Germany. Atmos Environ 45 3466-3474... 

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