7.6: Reduction of Air Pollutants Flashcards
Regulation: Pollution Credits
Companies that reduce emission well below EPA-set level earn pollution credits that they can sell to companies who release more
Regulation: CAFE Vehicle Standards
Requires vehicle manufacturers to work to make more efficient vehicles which burn less gasoline and release less NOx, PM, CO, CO2
Reducing Air Pollutants with a Vapor Recovery Nozzle
Captures hydrocarbon vocs that are released from gasoline fumes during refueling; it reduces VOCs and benzene (carcinogen)
Reducing Air Pollutants with a Catalytic Converter
Required on all vehicles after 1975; it contains platinum and palladium which binds to NOx and CO converting it to CO2, N2, O2, H2O
Reducing SOx with Crushed Limestone
Crushed coal is mixed with limestone before being burned with the calcium carbonate in the limestone combinign with SO2 to produce calcium sulfate which reduces the SO2 being emitted
Reducing NOx with Fluidized Bed Combustion
Fluidizing jets of O2 are pumped into the combustion bed which makes combustion more efficient as the coal is combusted at a lower temp which emits less NOx
Dry Scrubbers (NOx, SOx, VOCs)
A large column with chemicals (commonly calcium oxide) absorbs the compounds from exhaust streams
Wet Scrubbers (NOx, SOx, VOCs, PM)
A dry scrubber that also has mist nozzles that trap PM in water droplets which fall to the bottom of the scrubber or get trapped at the top by the mist eliminator
A sludge collection system traps polluted water for disposal
Reducing PM with Electrostatic Precipitator
Emissions are passed through a device with a negative charged electrode which gives particles a negative charge. these particles stick to postiviely charged collection plates which trap them and from there are disposed in landfills
Baghouse Filter (PM)
Fabric bag filters trap PM as air from combustion/industrial process passes through with the PM being collected and taken to a landfill
