Emissions combustion, coke

Phenanthrene occurs in fossil fuels and is present in products of incomplete combustion. Some of the known sources of phenanthrene in the atmosphere are vehicular emissions, coal and oil burning, wood combustion, coke plants, aluminum plants, iron and... 

As an example, consider heavy fuel oil (CH15, specific gravity, 0.95) atomized to a surface mean particle diameter of d, burned with 20 percent excess air to produce coke-residue particles having the original drop diameter and suspended in combustion products at 1204°C (2200°F). The flame emissivity due to the particles along a path of L m will be, with d in micrometers. 

Emissions from the underfire or combustion stack due to combustion of gas in the coke oven flues... 

The presence of polycyclic aromatic hydrocarbons in the environment is of obvious concern and, apart from specific occupational environments, human exposure to these compounds derives from combustion products released into the atmosphere. Estimates of the total annual benzo[aJpyrene emissions in the United States range from 900 tons (19) to about 1300 tons (20). These totals are derived from heat and power generation (37-38%), open-refuse burning (42-46%), coke production (15-19%) and motor vehicle emissions (1-1.5%) (19,20). Since the vast majority of these emissions are from stationary sources, local levels of air pollution obviously vary. Benzo[aJpyrene levels of less than 1 pg/1,000 m correspond to clean air (20). At this level, it can be estimated that the average person would inhale about 0.02 pg of benzo[aJpyrene per day, and this could increase to 1.5 pg/day in polluted air (21). 

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. 

Every FCCU will have its own relationship between excess oxygen, CRC, and CO emissions. The majority of FCCU also operate at or near an air blower or coke limit. For these units, minimizing excess oxygen will result in increased capacity and profitability. The trade-off is CRC and CO emissions. COP is used to accelerate CO combustion and allow the unit to operate at maximum profitability at low excess oxygen and stay within allowable CO emission limits. Figure 15.10 shows a typical relationship between excess O2, CO, and NO. ... 

PAHs are formed as the by-products of incomplete combustion of fossil fuels. These compounds have been identified in many emission sources, such as vehicle exhausts power plants chemical, coke, and oil-shale industries and municipal sewage (Trapido et al., 1995). Some PAHs are known to be carcinogens. PAHs have been observed to be degraded by ozone treatment in aqueous media. The degradation kinetics of five PAHs — anthracene,... 

ASTM D-6349. Standard Test Method for Determination of Major and Minor Elements in Coal, Coke, and Solid Residues from Combustion of Coal and Coke by Inductively Coupled Plasma-Atomic Emission Spectrometry. 

Infrared absorption is one of three standard test methods for sulfur in the analysis sample of coal and coke using high-temperature tube furnace combustion methods (ASTM D-4239). Determination of sulfur is, by definition, part of the ultimate analysis of coal (Chapter 4), but sulfur analysis by the infrared method is also used to serve a number of interests evaluation of coal preparation, evaluation of potential sulfur emissions from coal combustion or conversion processes, and evaluation of the coal quality in relation to contract specifications, as well as other scientific purposes. Infrared analysis provides a reliable, rapid method for determining the concentration of sulfur in coal and is especially applicable when results must be obtained rapidly for the successful completion of industrial, beneficiation, trade, or other evaluations. 

Khalili, N., Sche, P., and Holsen, T. (1995). PAH source fingerprints for coke ovens, diesel and gasoline engines, highway tunnels, and wood combustion emissions. Atmos. Environ. 29, 533—542. 

More stringent clean air requirements are also being imposed upon the FCC process. NO, emissions, produced by combustion of the coke during FCC catalyst regeneration, are being more strictly limited. FCC NO, reduction additives have been developed to minimize or reduce the amount of this pollutant produced by the FCC process. 

Incomplete combustion of organic material, forest fires and volcanic eruptions incomplete combustion of fossil fuels, coke oven emissions, aluminium smelters, vehicle exhausts 37, 4101,7... 

Combined Gas, Soot, and Particulate Emission In a mixture of emitting species, the emission of each constituent is attenuated on its way to the system boundary by absorption by all other constituents. The transmissivity of a mixture is the product of the transmissivities of its component parts. This statement is a corollary of Beer s law. For present purposes, the transmissivity of species k is defined as xk = 1 — Et. For a mixture of combustion products consisting of carbon dioxide, water vapor, soot, and oil coke or char particles, the total emissivity eT at any wavelength can therefore be obtained from... 

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