Residential combustion

The rank of coal (maturity) is an important factor that affects PAH emissions from residential combustion. PAH emission from various coals is found to have a relationship with their volatile contents, and the complete combustion of coals with a high volatile content is more difficult to achieve. Bituminous and sub-bituminous coals with high volatile content yield more PAHs when burned at low temperatures, such as residential combustion, while anthracite coal containing very little volatile matter can burn more completely and emit PAHs with a mass that is three orders of magnitude lower than bituminous coal. Smoky coal, which is burned as fuel for cooking and heating in unvented homes, produces combustion emissions composed primarily of parent PAHs and alkylated PAHs. 

However, despite all the progress being made, the uncontrolled production unavoidably leads to environmental problems such as climate change or emission of toxic products. For example, dioxins and furans are unintentionally formed and released from various sources like open burning of waste, thermal processes in the metallurgical industry, residential combustion sources, motor vehicles, particularly those burning leaded gasoline, fossil fuel-fired utility and industrial boilers, waste oil refineries etc... 

Using USA, Sweden and Norway as examples, the major known sources of PAH were residential combustion of wood, the aluminium industry, forest fires, coke manufacturing, oil fired intermediate commercial/industrial boilers, mobile sources and residential combustion of bitumious coal. 

De Angelis, D.G., Ruffin, D.S., Peters, J.A. and Reznik, R.B., Source Assessment Residential Combustion of Wood, EPA-600/2-80-042b 1980, Research Triangle Park. 

Man-made sources The burning of coal and oil accounted for virtually all the sulfur oxides emitted from man-made sources in the eastern U.S., about 30.6 million tonnes (calculated as sulfate) in 1980. (Table 2). (Emissions are estimated from the sulfur content of each type of fuel and the amount of fuel consumed.) Electric utilities contributed 71% of the total SO2, with the majority of emissions coming from coal-fired power plants. The remainder came chiefly from industrial, commercial and residential combustion transportation smelters and industrial processes. An additional 2.1 million tonnes entered the U.S. from Canada, principally emissions from metal smelters,- and 1.2 million tonnes entered the region from the western U.S. ... 

The air pollution problems associated with combustion of coal are of major concern. These problems generally occur away from the coal mine. The problems of atmospheric emissions due to mining, cleaning, handling, and transportation of coal from the mine to the user are of lesser sigruficance as far as the overall air pollution problems are concerned. Whenever coal is handled, particulate emission becomes a problem. The emissions can be either coal dust or inorganic inclusions. Control of these emissions can be relatively expensive if the coal storage and transfer facilities are located near residential areas. 

Traditionally, residential mechanical equipment has been treated as independent devices that have little or no impact on the rest of the building other than the obvious stated purpose. Bath fans, dryers, and kitchen ranges are assumed to exhaust moisture, lint, and cooking by-products, but to have no impact on the performance of chimneys. Instances have been reported that show that this is not the case in some houses where the fireplaces and other combustion appliances backdraft52 when one or more of the exhaust fans are in operation. Houses have been reported in which the operation of exhaust devices increases the radon concentration.53 Houses have been found in which pressure differences between different rooms of the house caused by HVAC distribution fans have increased energy costs,54 occupant discomfort,54,55 condensation of the building shell,55 and radon concentrations in parts of the houses.29,56 All of these effects are the result of air pressure relationships created by the interaction of equipment, indoor/outdoor temperature differences, wind velocity, and moisture and radon availability. 

Basic box models cannot portray effects of nonuniform source patterns. If, for particular chemical species or particular source classes, the dependence of emissions on population density or other identifiable parameters is apparent and significant, we have used modifications to the box modeling approach. As an example, it might be assumed in modeling products of combustion of the lighter fuel oil distillates that source distribution patterns are proportional to population density patterns, because most of such fuel is burned in residential furnaces in cold weather cities. 

The use of sensors for surveillance of industrial combustion processes is state of the art. Especially optical sensors detect the existence of a flame. With decreasing furnace performance the amount of installed sensors declines. In residential appliances there are nearly no sensors installed because the costs for both, sensors and actuators, have to be balanced with the technical profit. The efforts for setting up combustion controls are very ambitious but in many cases not successful. First a distinction has to be made between sealed boilers and those that are open towards the room in which they are installed. The resulting controls cannot be interchanged between these two groups of appliances. 

Murphy, D.J., R.M. Buchan, and D.G. Fox. 1982. Ambient particulate and benzo[a]pyrene concentrations from residential wood combustion, in a mountain community. Pages 567-574 in M. Cooke, AJ. Dennis, and G.L. Fisher (eds.). Polynuclear Aromatic Hydrocarbons Physical and Biological Chemistry. Battelle Press, Columbus, OH. 

When hydrogen is burned in a combustion chamber instead of a conventional boiler, high-pressure superheated steam can be generated and fed directly into a turbine. This could cut the capital cost of a power plant by one half. While hydrogen is burned, there is essentially no pollution. Expensive pollution control systems, which can be almost one third of the capital costs of conventional fossil fuel power plants are not required. This should also allow plants to be located closer to residential and commercial loads, reducing power transmission costs and line losses. 

Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle-phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The gas-phase emission rates of acenaphthene were 2.02 mg/kg of pine burned, 1.15 mg/kg of oak burned, and 0.893 mg/kg of eucalyptus burned. 

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