2011+Emission+controls

2011+Emission+controls - Emission Controls 1 Types of...

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1 Emission Controls
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2 Types of Emissions Carbon dioxide Historically not an issue Nitrogen Oxides Sulfur Mercury Unburned fuels – Mostly Carbon Monoxide Other (non fuel)Particulates
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3 What we need to do:
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4 Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to that of the same mass of carbon dioxide (whose GWP is by convention equal to 1). The GWP depends on the following factors: – the absorption of infrared radiation by a given species – the spectral location of its absorbing wavelengths – the atmospheric lifetime of the species
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Global warming potential (GWP) 5
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How do we limit or control CO 2 ? Return to the stone age Use fuels high in H and low in C Use fuels with higher GWP – Burning is better then emitting directly Sequester in any of a number of ways 6
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7 Carbon monoxide During World War Two, carbon monoxide was used to keep motor vehicles running in parts of the world where gasoline was scarce. External charcoal or wood burners were fitted, and the carbon monoxide produced by gasification was piped to the carburetor.
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Controlling Carbon monoxide Arrange for complete burning of fuel – Extra oxygen helps Use Catalytic converter – Rutgers Cogen Installing Lowers temperature in combustors by spraying water Lowers Nox, but increases CO Catalyst bed causes CO to react LATER in HRSG – Replaces duct burner 8
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9 Nitrogen oxides or “NOx” Elemental Nitrogen (N 2 ) is good Nitric oxide (NO)is the primary contaminant 27% of NOx comes from power plants Sierra club says 40%? 49% from vehicles, 19% Industrial/Commercial/Residential Nitrous Oxide (N 2 O) a secondary contaminant, formed by the combination of atmospheric oxygen(O 2 ) and nitric oxide (NO) in the presence of sunlight. Is a greenhouse gas Also a general anesthetic Nitrogen dioxide (NO 2 ) is a prominent air pollutant
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10 Nox is involved with Ozone Ozone is O 3 Ozone is chemically unstable, and when left to its own devices, it doesn't linger long. It is also extremely reactive with other compounds. This can be good or bad, depending on where the ozone molecules happen to be.
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11 Stratospheric ("Good") Ozone When ozone occurs in the upper atmosphere, (where it's supposed to be), it absorbs energy from sunlight. – In the process, it filters out ultraviolet rays, making life on the planet possible -- and far more comfortable. Unfortunately, because ozone is so highly reactive, other chemicals can easily bond with the ozone molecules, depleting the protective ozone layer. (That's the cause of the "ozone hole“)
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Ground Level ("Bad") Ozone Ozone forms when sunlight reacts with volatile organic compounds and nitrogen oxides. Smog is ground level ozone!
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2011+Emission+controls - Emission Controls 1 Types of...

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