Air Pollution

Essential Question What causes air pollution?

Enduring Understandings Air pollution can come in many forms and is caused by natural as well as human processes.

Review Layers of the atmosphere Troposphere Stratosphere Mesosphere Thermosphere Exosphere

Review Atmosphere Nitrogen 78% Oxygen 21% Other 1% Argon 0.9% CO2 0.036% CH4 0.00017% NOx 0.00003% O3 0.000004%

All right, enough review…. On to the new stuff!

Air Pollution Condition in which the air contains harmful substances at unhealthy levels

Air Pollution Condition in which the air contains harmful substances at unhealthy levels

Air Pollution Condition in which the air contains harmful substances at unhealthy levels

Human Sources Fossil Fuels Transportation Electricity Generation Oil Electricity Generation Coal Construction Agriculture Industry

Bhopal India Dec. 2, 3 1984 27 tons methyl isocyanate 3,000-20,000 deaths

Natural Sources Volcanoes Pollen and Spores Dust

Primary Pollutant A pollutant that enters the atmosphere as a direct result of human activity CO2 CO SO2 NOx VOCs PM

Primary Pollutant CO – Carbon Monoxide Odorless Colorless Combustion of fossil fuels Interferes w/ blood’s ability to carry oxygen Drowsiness Death

Primary Pollutant NOx – Nitrogen Oxides High temp combustion of fossil fuels Transportation Industry Acid Rain Smog Respiratory Infections Cancer

Primary Pollutant SO2 – Sulfur Dioxide Burning of what else? fossil fuels Refineries Coal Burning Power Plants Acid Rain Respiratory Ailments Damaging to Plant Life

Primary Pollutant VOC – Volatile Organic Compounds Burning of fossil fuels Paints Offgasing of plastics and vinyls New car smell Smog Cancer Fry your brain

Primary Pollutant PM – Particulate Matter Tiny Solids or liquids Smoke Hydrocarbons Construction Agriculture Acid Rain Respiratory Problems Cancer

Secondary Pollutants A pollutant that results from a primary pollutant chemically reacting with another primary pollutant or naturally occuring substance.

Secondary Pollutants O3 – Ozone H2SO4 (Sulfuric Acid) HNO3 (Nitric Acid) Acid Rain

Pollution from Cars 1/3 of all pollution from transporation 234,852,000 registered vehicles 3,982,000 miles of roadway 2,600,000,000,000 miles driven 90% from passenger cars Source: U.S. Census Bureau 2004

How is gasoline derived from oil? Crude oil (petroleum) is made of hydrocarbons Hydrocarbon = Hydrogen + Carbon Also Sulfur, Nitrogen, Oxygen, Metals, Salts Hydrocarbons contain a lot of energy! Crude oil is refined (distillation) to separate out different hydrocarbons

Products made from oil Clothing Ink Heart Valves Crayons Parachutes Telephones Deodorant Pantyhose Carpets Motorcycle helmets Pillows Shoes Toilet seats Movie film Credit cards Aspirin Golf balls Sunglasses Fishing rods Soft contact lenses Shaving cream Footballs

More Products made from petroleum Tires Toothbrushes Toothpaste Lipstick Eyeglasses Ice chests Life jackets TV cabinets Car battery cases Refrigerants Artificial Limbs Dentures Ballpoint pens Boats Nail polish Curtains Vitamin capsules Skis Insecticides Perfumes Petroleum jelly Food preservatives

Exhaust Emissions Combustion: “Perfect” Combustion Typical Combustion Hydrocarbons in fuel mix with oxygen 14.7:1 Stoichiometric “Perfect” Combustion Fuel + Air = CO2 + H2O + N2 Typical Combustion Fuel + Air = HC + NOx + CO + CO2 + H2O

Exhaust Pollutants Hydrocarbons (HC) Result of incomplete burning of fuel Component of smog Particulate Matter Black Stuff

Exhaust Pollutants NOx CO CO2

Catalytic Converter Part of exhaust system Convert harmful pollutants to less harmful emissions HC H2O CO CO2 NOx  N2

Reduction Catalyst 2NO => N2 + O2 or 2NO2 => N2 + 2O2

Oxidation catalyst 2CO + O2 => 2CO2

Drawbacks to Catalytic Converters Platinum Only works at high temperatures

Evaporative Emissions Occur when fuel evaporates before it is burned

Evaporative Emissions Diurnal Evaporation increases as temperature increases

Evaporative Emissions Running Losses Engine and exhaust vaporize fuel while car is running

Evaporative Emissions Hot Soak Engine remains hot after car is turned off and fuel continues to evaporate

Evaporative Emissions Refueling Fuel vapors are forced out of tank when displaced by fuel

Reducing Pollution from Cars Avoid unnecessary driving Consolidate trips Plan errands Car pool Share a ride Bike or Walk

Reducing Pollution from Cars Maintain your car Extend Life Increase resale value Better gas mileage Change oil, filters, belts, fluids Tires inflated Octane

Reducing Pollution from Cars Idling Stop and Go driving Air conditioning High Engine Loads Cold temperatures Refueling