History of Air Pollution Policy
 Air policy became a state issue
– Oregon 1952 has statewide ordinance
– California takes this a step further
 Targets mobile sources of pollution
– 1955 APCA (plus ’59 & ’62 extensions)
– 1965 Motor Vehicle Air Pollution Control Act
– 1967 AQA
History of Air Pollution Policy
 Early versions of control acts had limited
effect
– Relied on states for standards
– Provided funds to states
– Required delineation of AQCR
 Air Quality Control Regions
 “Airsheds” similar to Watersheds
History of Air Pollution Policy
 State role was inadequate
– Largely voluntary (in effect if not in fact)
– The focus was on research, technical assistance
and training
– The need for federal focus was realized
 CAA of 1970
– Technically, amendments to original air quality
legislation
The Clean Air Act of 1970
 Established a strong federal control over air
pollution
– Power vested in EPA (newly created)
– Focus on two aspects
 Standards
 Methods / Technology for meeting standards
The Clean Air Act of 1970
 NAAQS (National Ambient Air Quality
Standards)
– Primary
 Human health-based
– Secondary
 Welfare-based
 Used if primary standards were insufficient to protect
non-human health (ag, forests, social values)
The Clean Air Act of 1970
 NAAQS determined by EPA
– States must determine quality in AQCRs
 Attainment or non-Attainment
 Implement a plan to maintain or increase air quality
in AQCRs
– NAAQS based on “dose-response” curve for
criteria pollutants
 Toxic concentration vs. theoretical threshold based
on sick-days
The Clean Air Act of 1970
 NAAQS and Criteria Pollutants
– Carbon Monoxide
– Nitrogen Dioxide
– Ozone (NOx + VOCs + sunlight)
– Lead
– PM
– Sulfur Dioxide
The Clean Air Act of 1970
 Sources of Pollution
– Mobile
 Direct
 Indirect
– Stationary
 Specific
 Area sources
Combustion
 Most fuels are “hydrocarbons”
– Hydrogen + Carbon
 Perfect Combustion:
– Ignition and air
– Hydrogen > water
– Carbon > carbon dioxide
 Combustion is inherently inefficient
Types of Pollution
 Comes from two types of emissions
– Evaporative
– Exhaust
 Evaporative
– Evaporation of uncombusted fuels
 Exhaust
– Tailpipe emissions
Types of Pollution
 Hydrocarbons
– Unburned fuel
– Partially burned fuel
– Reacts with nitrogen oxides to produce ozone
– Most prevalent pollutant
– Cancerous
– Irritant to eyes and lungs
Types of Pollution
 Nitrogen oxides
– Results from high pressure and temperature in
engines
– Nitrogen reacts with oxygen
– NOx signifies many types of oxides
– Precursor of ozone (with hydrocarbons)
– Contributes to acid rain
Types of Pollution
 Carbon Monoxide (CO)
– Incomplete combustion (low air-to-fuel ratios)
 “Choked” engines
 Cold starts
– Fuel is partially oxidized (unlike CO2)
– Reduces flow of oxygen to blood stream
– 2/3 of CO emissions come from mobile sources
Types of Pollution
 Carbon Dioxide (CO2)
– A product (with water) of “perfect” combustion
– It is nevertheless a Greenhouse Gas
Types of Pollution
 Ozone
– Formed from a chemical reaction outside of
engine
– Hydrocarbons + NOx + sunlight
– Severe irritant of mucous linings
Types of Pollution
 Evaporative Emissions
– Diurnal
– Running Losses
– Hot Soak
– Refueling
Types of Pollution
 Particulate Matter (PM)
– Solid or liquid particles
– Big Particles: 2.5>=x<=10 microns
 25-100 times thinner than a hair
– Small Particles
 <2.5 microns
Types of Pollution
 PM10
– Smoke, dirt, dust
– Mold, spores, pollen
– Mobile sources:
 Roadway erosion
 Tire erosion
Types of Pollution
 PM2.5
– Toxic organic compounds
– Heavy metals
– Mobile sources:
 Diesel combustion
 Asphalt manufacture (indirectly)
Pollution Controls
 Mandated through CAA
– Catalytic converters
– CAFE standards
– Tailpipe standards
Catalytic Converters
 Two-way
– Oxydizing Carbon Monoxide into Carbon Dioxide
– Oxydation of unburned hydrocarbons
Catalytic Converters
 Three-way
– Reduction of nitrogen oxides into nitrogen and
oxygen
– Oxydizing Carbon Monoxide into Carbon Dioxide
– Oxydation of unburned hydrocarbons
 How do they work?
Catalytic Converters
 Adverse Impacts
– Decreases fuel efficiency in some situations
– Increases emissions of carbon dioxide
– Input requirements of production include
palladium or platinum – a very toxic process
CAFE Standards
 Corporate Average Fuel Economy
 Varying Standards over time and among
class of autos
– Getting more strict over time
– Applies to passenger vehicles and light trucks
 2010 – 27.5 (autos) 23.5 (trucks)
 2011 – 30.2 (autos) 24.1 (trucks)
 HOPE: 35 mpg by 2016
Tailpipe Emissions Standards
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“Smog Checks”
Primarily in urban areas
Always in non-attainment areas
Hydrocarbons, CO, Nox
Testing to be clean for a day
Most test at idle
Some “treadmill” tests
Alternative Fuels
Alternative Fuel Types
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Ethanol
Biodiesel
Electricity
Hydrogen
Methanol
Natural Gas
Ethanol
 Ethyl Alcohol (grain alcohol)
 Currently used as an oxygenate in fuels
– Reduces CO levels
 85% blends are currently used (E85)
– FFVs (Flexible Fuel Vehicles)
 10% blend (E10) used as an additive
Ethanol Production
 High-sugar or convertible starch sources
– Beet and cane sugar; corn
 Think moonshine
 Relatively low EROEI (for corn)
– Energy Returned on Energy Invested
 Better EROEI for switchgrass
 Tradeoff for corn ethanol is tricky
– Food or fuel?
Ethanol Market
 E85 and E10 blends
 E10 is an additive in CO noncompliance
areas
 E85 used as an alternative fuel (defined by
Energy Policy Act of 1992)
 3 million FFVs sold
– Oddly, not many realize they can fuel with E85
 Used as an offset in CAFE standards
Ethanol Infrastructure
EPA Fuel FInder
Biodiesel
 Made from new and used vegetable oils and
fats
 20% mixtures (B20) can be used in all diesel
engines
 100% biodiesel can be used in most
engines built since 1994
Benefits of biodiesel
 Reduces amounts of unburned hydrocarbons, CO,
sulfates, particulate matter
 Negative relationship between fuel mix and these
emissions
 BUT…
 Levels of Nitrogen Oxides increase with higher
fractions of biodiesel in fuel mixture
Production of Biodiesel
 Made from new and used vegetable oils and
animal fats
 New or recycled oils
 Chemically reacted with alcohols to
produce:
– Fatty acid methyl esters (i.e., biodiesel)
Market for Biodiesel
 Authorized as an alternative fuel in the
Energy Conservation Reauthorization Act of
1998 (the reauthorization of the Energy
Policy Act of 1992)
 Relatively large presence in public fleets
 Projected to 2 billion gallons per year
– Assuming same levels of subsidy given to
ethanol and methanol producers
Market for Biodiesel
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Bus Fleets
Heavy Duty Trucks
Marine Vessels
Home Heating
Energy Generating Facilities
Biodiesel Availability
EPA Fuel FInder
Hydrogen Fuels
 Combustion and Electric Fuel Cells
 Very low energy density
– Efficient storage is problematic
Production of Hydrogen Fuels
 Splitting and recombining Hydrogen
molecules
 Demonstration
Market for Hydrogen
 Currently, none
 Prototype models
 Production and distribution problems for
hydrogen sources
 10 – 20 year horizon for market penetration
Hydrogen Availability
EPA Fuel FInder
Electricity
 Neighborhood Electric Vehicles
 Hybrid Electric Vehicles
Electricity Benefits
 No tailpipe emissions
 Lower fuel and maintenance costs
Electric Availability
EPA Fuel FInder
Methanol
 Commonly called “wood alcohol”
 Derived primarily from natural gas
 Alternatively, biomass and coal (nonpetroleum sources)
 Currently out of favor
– MTBE
 Seen as a likely source of hydrogen
Natural Gas
 Produced from gas wells or as part of
petroleum production process
 Primarily methane (CH4)
 LNG (Liquefied Natural Gas)
 CNG (Compressed Natural Gas)
Natural Gas Benefits
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One of the cleanest burning alternatives
CO reduced 90%
Nitrogen Oxides reduced 60%
CO2 reduced 30% – 40%
Natural Gas Market
 Pre-existing distribution system
 Public filling stations
 Slow-fill system for at-home overnight filling
LNG Availability
EPA Fuel FInder
Propane
Propane
 LPG (Liquefied Petroleum Gas)
 A byproduct of natural gas and petroleum
processing
 Most used in US is produced domestically
Propane Benefits
 Fewer ozone-forming emissions
 98% reduction in benzene and
formaldehyde
 Costs less than gasoline
 85% of domestic use comes from domestic
supply
Propane Market
 200,000 vehicles in fleets currently on road
 Can purchase dedicated new vehicle
 Can purchase aftermarket conversion kits
Propane Market
EPA Fuel FInder
Environmental Policies
 Station Cars
 TDM
– Ride-sharing
– Workweek reductions
– Flexible hours
– Telecommuting
Environmental Policies
 CAFE Standards
 Voluntary efforts
– Terra Pass
– Zip Cars
– Drive on Demand (U-Haul)