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CE 3231 - Introduction to Environmental Engineering and Science. Readings for This Class: 5.5-5.6. O hio N orthern U niversity. Chemistry, Microbiology & Material Balance. Introduction. Water & Air Pollution. Env Risk Management. Air Pollution Control Technologies
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CE 3231 - Introduction to Environmental Engineering and Science Readings for This Class: 5.5-5.6 Ohio Northern University Chemistry, Microbiology & Material Balance Introduction Water & Air Pollution Env Risk Management Air Pollution Control Technologies As long as we burn fossil fuels, we will need treatment control technologies in order to attempt to offset the negative releases of pollution to the environment. This lecture presents and introduction to the most common air pollution control technologies.
Lecture 28Air Pollution Control Technologies(Air Quality III)
Air Pollution Control Device Topics Covered Include: Reason for Air Pollution Control Devices Types of Controls Description of Common Controls
C(x,0) dependent on Q Air pollution control devices seek to limit Q Q = emission rate of pollutants, g/s
Air Pollution Control Technology • Precombustion • Combustion • Post Combustion http://www.energyeducation.tx.gov/
Air Pollution Control Technology • Precombustion American Coal Foundation (http://www.teachcoal.org/aboutcoal/articles/coalreserves.html) http://online.wsj.com/article/SB124414770220386457.html
Air Pollution Control Technology • Precombustion http://www.instituteforenergyresearch.org/states/ohio/
Air Pollution Control Technology • Combustion Boiler Technology http://geosci.uchicago.edu/~moyer/GEOS24705/Images/CoalPowerPlant_TVA.gif
Air Pollution Control Technology • Combustion Fluidized Bed Combustion - still boiling water, but feed (coal) is mixed with limestone to remove SOx during the process (90% removal of Sox). - Operates at lower temperature (~800 C) than conventional boiler and reduces NOx formation due to more efficient combustion <http://www.britannica.com/EBchecked/media/113942/Schematic-diagram-of-a-fluidized-bed-combustion-boiler>.
Air Pollution Control Technology • Post- Combustion • Desulfurization • Electrostatic precipitators (dry and wet) • Bag house filters • Cyclone collectors sulfur particulates
Post Combustion • Desulfurization • Wet scrubbing • Alkaline dissolved in water • Sprayed alkali water droplets absorb sulfur http://en.wikipedia.org/wiki/File:Flue_gas_desulfurization_unit_EN.svg Simplification: H2O + CaCO3(solid) + SO2 (gas) → CaSO3 (solid) + CO2 (gas) + H+
Post Combustion • Electrostatic Precipitator • Voltage applied across plates • Attracts ions of opposite charge http://en.wikipedia.org/wiki/Electrostatic_precipitator
Post Combustion • Bag house filter • Dry filtration of gas • Air filters through fabric or other media http://www.tethis-lab.com/anima/pp-baghouse-filter.html
Post Combustion • Cyclone • Dry filtration of gas • Dust spun out of air http://www.dustcollectorscyclone.com/
Air Control Technologies • Even if we can remove the NOx, SOx, and particulates, we still have to worry about CO2 CleanCoal Technologies Parts 1 & 2 AirPollution Control Devices Video http://www.metoffice.gov.uk/education/secondary/students/smog.html