Vehicle Vehicle EmissionsEmissions

What will we learn today?What will we learn today?

• Atoms, molecules, and elementsAtoms, molecules, and elements• What is combustion?What is combustion?• Exhaust emissionsExhaust emissions• IDEAL products of burningIDEAL products of burning• REAL products of burningREAL products of burning

Click here for a short chemistry lesson.

Skip chemistry andgo to combustion.

AtomsAtoms

An atom contains:An atom contains:

• A A nucleusnucleus made made up of up of protonsprotons and and neutronsneutrons

• ElectronsElectrons orbit orbit the nucleus. the nucleus.

The length of an atom is: cm,, 000000100

1

Elements and moleculesElements and molecules

• Different Different elementselements have different have different numbers of numbers of protonsprotons and and electronselectrons. .

• The periodic table shows all the known The periodic table shows all the known elements.elements.

• Two or more atoms can join together to Two or more atoms can join together to form a form a molecule.molecule.

example: Water (Hexample: Water (H22O)O)

H H

OWhat elements make up water?

H H

O

Introduction to Emission Introduction to Emission ChemistryChemistry

• Water (HWater (H22O) is made O) is made of two types of atomsof two types of atoms– Hydrogen (H)Hydrogen (H)– Oxygen (O)Oxygen (O)

• Hydrogen and oxygen Hydrogen and oxygen are found naturally in are found naturally in the atmosphere as the atmosphere as diatomic molecules: Hdiatomic molecules: H2(g)2(g) and Oand O2(g)2(g)

Hydrogen

Oxygen

Water is formed Water is formed during combustionduring combustion

What is Combustion?What is Combustion?

• Combustion occurs when a fuel Combustion occurs when a fuel reacts with oxygen to give off reacts with oxygen to give off heat and light.heat and light. **Air provides enough oxygen (~20% oxygen, Air provides enough oxygen (~20% oxygen, ~80% nitrogen)~80% nitrogen)

• Fuels are typically made of Fuels are typically made of carbon and hydrogen carbon and hydrogen (hydrocarbons)(hydrocarbons)

What are some common fuels?What are some common fuels?

Why Do We Care?Why Do We Care?

• Burning of fuel is the energy source for Burning of fuel is the energy source for almost all types of automobiles almost all types of automobiles

• Combustion accounts for 85% of all worldwide Combustion accounts for 85% of all worldwide electricity productionelectricity production

Source: http://museum.nist.gov/exhibits/timeline/item.cfm?itemId=27

Source: http://www.sunocoinc.com/market/marketplace.htm

BUTBUT,,

• Combustion accounts for 90% of all Combustion accounts for 90% of all airborne pollutionairborne pollution

• Air pollution can lead to lung problems Air pollution can lead to lung problems and shorter life spansand shorter life spans

Link to “Lung Attack” activity

CombustionCombustion• Ideal combustion produces only carbon Ideal combustion produces only carbon

dioxide, water, and dioxide, water, and ENERGYENERGY::

– Natural Gas:Natural Gas:CHCH44 + 2 O + 2 O22 →→ CO CO22 + H + H22OO

– Gasoline (approximate):Gasoline (approximate):CC88HH1616 + 12 O + 12 O22 →→ 8 CO 8 CO22 + 8 H + 8 H22OO

– Glucose in your blood/muscles:Glucose in your blood/muscles:CC66HH1212OO66 + 6 O + 6 O22 →→ 6 CO 6 CO22 + 6 H + 6 H22OO

Real CombustionReal Combustion•Fuel does not exist as a pure substanceFuel does not exist as a pure substance

– varying hydrocarbon chainsvarying hydrocarbon chains

*Jet and diesel fuel contain hydrocarbon chains of 12 to 20 *Jet and diesel fuel contain hydrocarbon chains of 12 to 20 carbons in length. Fuel oil contains hydrocarbons 20 to 40 carbons in length. Fuel oil contains hydrocarbons 20 to 40

carbons long.carbons long. – sulfur (S)sulfur (S)– nitrogen (N)nitrogen (N)– oxygen (O)oxygen (O)

•The combustion process is NEVER The combustion process is NEVER complete and NEVER ideal. You will complete and NEVER ideal. You will always get more than just COalways get more than just CO22 and H and H22OO

Emissions: AutomobilesEmissions: Automobiles

• Hydrogen (H)Hydrogen (H)

• Carbon (C)Carbon (C)

• Nitrogen (N)Nitrogen (N)

• Oxygen (O)Oxygen (O)

•Let’s look at what happens in ideal and real combustion in automobiles. The symbols we will use are shown below:

Ideal vs. Real CombustionIdeal vs. Real Combustion

Hydrocarbon

Oxygen

NitrogenIdeal

Real

NitrogenWaterCarbon dioxide

Carbon dioxide Water Nitrogen

Carbon monoxide Nitrogen dioxide

Unburned hydrocarbon Nitrogen monoxide

Primary Emissions from Primary Emissions from AutomobilesAutomobiles

• Carbon monoxide (CO)Carbon monoxide (CO)

• Oxides of nitrogen (NO, NOOxides of nitrogen (NO, NO22))

• Carbon as soot or particulatesCarbon as soot or particulates• Unburned fuel (hydrocarbons)Unburned fuel (hydrocarbons)

• Carbon dioxide (COCarbon dioxide (CO22))

• Water (HWater (H22O)O)

Details of primary pollutants

Carbon MonoxideCarbon Monoxide

• Carbon monoxide (CO) – a non-irritatingCarbon monoxide (CO) – a non-irritating (won’t make you cough),(won’t make you cough), colorless, tasteless, colorless, tasteless, and odorless gas.and odorless gas.

• Source: rich combustion - too Source: rich combustion - too littlelittle air air or too or too muchmuch gasoline gasoline

*Other sources: cigarette smoke or faulty household *Other sources: cigarette smoke or faulty household furnaces*furnaces*

Carbon MonoxideCarbon Monoxide

• CO isCO is POISIONOUS POISIONOUS because it reduces because it reduces the ability of blood to bring oxygen to the ability of blood to bring oxygen to the body’s cells and tissues.the body’s cells and tissues.

Remember that oxygen is needed Remember that oxygen is needed for the combustion that gives our for the combustion that gives our

bodies energy.bodies energy.

Nitrogen OxideNitrogen Oxide

• Nitrogen oxide Nitrogen oxide (NO(NOxx: mainly NO, NO: mainly NO, NO22))

• Source: lean combustion - too Source: lean combustion - too littlelittle gasoline or too gasoline or too muchmuch air air

Nitrogen OxideNitrogen Oxide

– Environmental Effects: Environmental Effects:

• NONO22 is an component of is an component of acid rainacid rain – can damage trees and lakescan damage trees and lakes

• NONOXX reacts with other chemicals in sunlight to reacts with other chemicals in sunlight to

produce ozone produce ozone smogsmog (brownish haze) (brownish haze)

– Health Effects: Health Effects: • Lung damageLung damage• Illnesses such as asthma, Illnesses such as asthma, bronchitis,bronchitis, and and

emphysemaemphysema – (sicknesses caused by problems with breathing (sicknesses caused by problems with breathing

passages and lungs)passages and lungs)

NONOxx Emissions in the U.S. Emissions in the U.S.

• Density map of 1999 NODensity map of 1999 NOxx emissions, by county. emissions, by county.– Highly populated areas have high concentration of NOHighly populated areas have high concentration of NOxx

– Why?Why?

NONOxx Emissions Emissions

NOx emissions by source, 1999

NOx Emissions

(Contributions by Source)

55%40%

4%

1% Transportation

Fuel Combustion

IndustrialProcesses

Miscallaneous

Particulate Matter (PM)Particulate Matter (PM)

• Particulate Matter (PM)Particulate Matter (PM) - small solids - small solids and liquids suspended in the air.and liquids suspended in the air.– ex: Dust, Smoke, Sootex: Dust, Smoke, Soot

• Source:Source: burning of wood, diesel and burning of wood, diesel and other fuels by vehicles, power plants, other fuels by vehicles, power plants, and also agriculture.and also agriculture.

Particulate Particulate MatterMatter

– Health effects:Health effects:• Nose and throat irritation Nose and throat irritation • lung damage, bronchitislung damage, bronchitis• early deathearly death

– Environmental effects:Environmental effects: • main source of haze that reduces main source of haze that reduces

visibility, discolors clothes and visibility, discolors clothes and furniture.furniture.

Secondary PollutantsSecondary Pollutants

• When When emissionsemissions react with react with other other chemicalschemicals in the atmosphere, they in the atmosphere, they make make secondary pollutantssecondary pollutants..

Examplesof secondary pollutants

Greenhouse GasesGreenhouse Gases•Green house gasesGreen house gases

– Gases that trap heat like a blanket Gases that trap heat like a blanket surrounding the Earth. surrounding the Earth.

• A normal concentration of these gases keep A normal concentration of these gases keep our planet at a steady temperature, but the our planet at a steady temperature, but the temperature can rise if we have too many in temperature can rise if we have too many in the atmosphere.the atmosphere.

•Greenhouse gases:Greenhouse gases:– Carbon dioxide (COCarbon dioxide (CO22): normal combustion): normal combustion– Methane: coal production, landfills, livestockMethane: coal production, landfills, livestock– Water: airplanes and from surface water that Water: airplanes and from surface water that

evaporates as the Earth becomes warmer!!!evaporates as the Earth becomes warmer!!!

Some of the sun’s radiation is reflected back into space by the atmosphere and Earth.

EARTH

SPACE

ATMOSPHERE

Some of the sun’s radiation passes through the atmosphere and hits the Earth to warm it up.

After bouncing off the Earth, the radiation has lower energy that is absorbed by greenhouse gases.

Secondary Secondary PollutantsPollutants

• But wait! There’s more! But wait! There’s more!

NONOXX reacts with other chemicals in reacts with other chemicals in sunlight to produce ozone sunlight to produce ozone Ozone Ozone is called smog (brownish haze) in is called smog (brownish haze) in the lower atmospherethe lower atmosphere

Smog and PM reduce visibility and Smog and PM reduce visibility and lead to health problems (asthma, lead to health problems (asthma, bronchitis,bronchitis, emphysemaemphysema))

OzoneOzone• Ozone is a colorless odorless Ozone is a colorless odorless

gas made of oxygen. gas made of oxygen.

• Ozone is OOzone is O33 - three oxygen - three oxygen atoms joined together. atoms joined together.

• Ozone is helpful in the upper Ozone is helpful in the upper atmosphere by shielding us atmosphere by shielding us from ultraviolet light, but it from ultraviolet light, but it is a component of smog in is a component of smog in the lower atmospherethe lower atmosphere

O OO

ConclusionConclusion

It is impossible to eliminate harmful It is impossible to eliminate harmful emissions, but… it is the emissions, but… it is the responsibility of every one of us to responsibility of every one of us to reduce energy consumption!!reduce energy consumption!!

Emission-related definitions (EPA)