1994 Fiscal Year Final Research Report Summary
The formation Mechanism of Nitrogen Dioxide in Combustion Field and Its Emission Control
Project/Area Number |
05650208
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Thermal engineering
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Research Institution | Takushoku University |
Principal Investigator |
HORI Morio Takushoku University, Faculty of Engineering, Professor, 工学部, 教授 (40013685)
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Co-Investigator(Kenkyū-buntansha) |
MATSUNAGA Naoki Takushoku University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (10199820)
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Project Period (FY) |
1993 – 1994
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Keywords | Oxides of Nitrogen, / Nitrogen Dioxide, / Air Pollution, / Combustion, |
Research Abstract |
The present research has been performed to obtain primarily the fundamental experimental data on the formation mechanism of nitrogen dioxide (NO_2) in combustion field by using flow reactor.NO_2 is a toxic constituent of the nitrogen oxides (NO_x) emitted from combustion systems. The important results of the present research are summarized in the following. 1.The analysis of the NO_2 emission data of combustion system shows that the proportion of NO_2 to NO_x in the exhaust ranges ordinary from 20% to 80%. 2.The effect of hydrocarbons on the formation process of NO_2 in a quartz flow reactor (total lenght : 795mm, inner dia. : 16mm, residence time : 1.46s) has been studied using a reacting flow of dry-air/No (20ppm) /hydrocarbon gas. The experimental parameters were inital hydrocarbon concentration (0-100ppm) , type of hydrocarbons (C_1-C_3, five kinds) , and reactor temperature (600-1100K) . (1) The formation rate of NO_2 increases by increasing the initial hydrocarbon concentrations due to the promotion effect of the hydrocarbons on the conversion of NO to NO_2. (2) The promotion effect depends strongly on the type of the hydrocarbons. Among five hydrocarbons employed, ethylene and propane show much stronger effect than methane and propylene. (3) The formation rate of NO_2 in a initial stage of reaction increases rapidly by increasing the reactor temperature. Although, above 1000K,NO_2 once formed is reduced to NO in a middle stage of reaction. Therefore, NO_2 can exist in a final stage of reaction only within a certain temperature range (700-1000K) . 3. The results of a chemical kinetic calculation using 115 elementary reactions for hydrocarbon-oxidation/NO/NO_2 system agree qualitatively with the measurements of the flow reactor. 4. As the possible methods of controlling NO_2 emission, the lowering of hydrocarbon concentration and the removal of relatively low temperature region in combustore, and the use of methane or propylene as fuel can be suggested.
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Research Products
(10 results)