Power generation combustion process

Combustion is an applied science that is important in transportation, power generation, industrial processes, and chemical engineering. In practice, combustion must simultaneously be safe, efficient, and clean. 

A process development known as NOXSO (DuPont) (165,166) uses sodium to purify power plant combustion flue gas for removal of nitrogen oxide, NO, and sulfur, SO compounds. This technology reHes on sodium metal generated in situ via thermal reduction of sodium compound-coated media contained within a flue-gas purification device, and subsequent flue-gas component reactions with sodium. The process also includes downstream separation and regeneration of spent media for recoating and circulation back to the gas purification device. A full-scale commercial demonstration project was under constmction in 1995. 

Thermal energy, power generation, and incineration have several factors in common. All rely on combustion, which causes the release of air pollutants all exhaust their emissions at elevated temperatures and all produce large quantities of ash when they consume solid or residual fuels. The ratio of the energy used to control pollution to the gross energy produced can be a deciding factor in the selection of the control system. These processes have important differences which influence the selection of specific systems and devices for individual facilities. 

Nitrogen oxides are generated by both human and nonhuman action, but the major sources of NO, are high-temperature combustion processes such as those occurring in power plants and automobile engines. Natural sources of NO., include lightning, chemical processes that occur in soil, and the metabolic activities of plants. 

The introduction of the internal combustion engine in the late nineteenth century opened up an entirely new approach to combined heat and power. Rather than using the same fluid for the heat and power process as was the case with hot air and steam processes, the tremendous waste heat generated by the internal combustion process can easily be transformed into useful heat. Cogeneration applications using stationary engines were common in Europe prior to World War I and remain quite popular because the heat is relatively... 

The gas turbine shown in Figure 3-7 is an open-cycle type. An open-cycle type gas turbine uses the same air that passes through the combustion process to operate the compressor. This is the type most often used for stationary power unit applications. A typical example of power requirements for an open-cycle type gas turbine would be for the unit to develop a total of 3,000 hp. However, about 2,000 hp of this would be needed to operate its compressor. This would leave 1,000 hp to operate the generator (or other systems connected to the ga.s turbine). Thus, such a gas turbine power unit would be rated as a 1,000-hp unit because this is the power that can be utilized to do external work. 

Tests conducted in Finland and Sweden have indicated the viability of using waste paper and plastic packaging as a fuel in a conventional power plant rather than in a municipal solid waste incinerator. If the process is accepted, as much as 30 million tonnes of the 50 million tonnes of combustible packaging which Europe consumes each year could be used for power generation. The feasibility of the initiative is discussed, and its implications in terms of future power plant construction. APME... 

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