Motor Vehicle Emissions and their Environmental Impacts

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Motor Vehicle Emissions and their Environmental
Impacts

• Two key concerns/drivers 
• Air pollution and its effects on human health
• GHGs and Global climate change
• The Sustainable Transportation context
• Local, regional, and global impacts of transport
• Emissions, noise, resource use

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Course outline

• Fuels and technologies
• Pollutant formation
• Emission measurement and characterization
• Emission control technology
• Emission modelling
• Air quality modelling
• Human health impacts

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MOTOR VEHICLE EMISSIONS OF CONCERN FOR HUMAN
HEALTH

• Criteria Air Contaminants (CACs) the pollutants
  regulated on the basis of human health
  criteria CO, NOx, NMHC, PM10 (PM2.5)
• Non-regulated pollutants, (or aspects) of recent
  (and/or increasing) concern, e.g.
• benzene
• formaldehyde
• acetaldehyde
• 1,3 butadiene
• MMT
• number and chemical composition of PM10

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Motor vehicle emissions and human health

• We have the technology to minimize direct and
  indirect human health effects
• Further improvements still possible
• Aftertreatment technology
• Fuel cell applications in transportation
• Hybrid vehicles
• Implementation of technology uneven around the
  world correlating with economic development
  levels
• Other issues related to transportation may become
  dominant
• Noise
• Land use patterns
• Greenhouse gas emissions

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Motor vehicle emissions and climate change

• Transportation is a major (and increasing)
  contributor to global CO2 emissions
• Technological solutions for reducing
  transportation CO2 emissions
• much more difficult than other sources
• much more difficult than air pollutant emissions.
• Significant reductions will probably be achieved
  only through a combination of
• technological fix
• Changes in transportation patterns
• ?Sustainable transportation ?

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Sustainable Development

• Development that meets the needs of the present
  without compromising the ability of future
  generations to meet their own needs.
• Elements of sustainability
• Economic
• Social
• Environmental

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Environmentally Sustainable Transport
Organization for Economic Co-operation and
Development (OECD)

• Types of impact on the environment
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• Local and regional impacts of atmospheric
  emissions.
• Of most concern among this type of emission are
  those that raise the concentration of ozone (O3)
  and breathable particulate matter (PM) near
  ground level, severely impacting human health.
  Ground-level ozone is formed as a result of the
  action of sunlight on mixtures of nitrogen oxides
  (NOx) and volatile organic compounds (VOCs),
  which are both components of the exhaust gases of
  motor vehicles propelled by internal combustion
  engines. Accordingly, criteria were used
  concerning each of NOx, VOCs, and PM.

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Environmentally Sustainable Transport
Organization for Economic Co-operation and
Development (OECD)

• Types of impact on the environment
•  
• Global impacts of atmospheric emissions.
• In addition to numerous pollutants with likely
  global impacts (e.g. CO, lead, tropospheric
  ozone, persistent organics, methane, N2O, etc.),
  the transport related emission of greatest
  concern is carbon dioxide (CO2) on account of its
  likely involvement in climate change. CO2 is a
  major component of motor vehicle exhaust
  accordingly, one of the criteria concerned CO2
  emissions, and their reduction.

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Environmentally Sustainable Transport
Organization for Economic Co-operation and
Development (OECD)

• Types of impact on the environment
• Local and regional impacts not resulting from
  atmospheric emissions.
• The remaining two criteria concerned noise and
  land use. In many places, noise is the most
  important transport related problem. In some
  places, land use for transportation is perceived
  to be a key issue in that it is often both a
  factor generating transport activity and a
  contributor to environmental stress.

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OECDs Environmentally Sustainable Transport
(EST) Project

• ENVIRONMENTALLY SUSTAINABLE TRANSPORT (EST)
  FUTURES, STRATEGIES AND BEST PRACTICE, OECD 2000.
• Synthesis Report
• http//www.oecd.org/dataoecd/15/29/2388785.pdf
• Guidelines
• http//www.oecd.org/dataoecd/53/21/2346679.pdf

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the EST project developed the following brief
definition of an environmentally sustainable
transport system as one where,

• transportation does not endanger public health or
  ecosystems and meets needs for access consistent
  with
• (a) use of renewable resources below their rates
  of regeneration, and
• (b) use of non-renewable resources below the
  rates of development of renewable substitutes.

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KEY SIGNS OF UNSUSTAINABLE TRANSPORT TRENDS(from
OECD EST Guidelines)

• Climate protection the CO2 criterion
• Regional air quality the NOx and VOC criteria
• Local air quality the particulate matter (PM)
  criterion
• Quietness the noise criterion
• Land use/take criterion

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Motor Vehicles

• Internal combustion (IC) engines
• Spark ignition (SI) - gasoline, propane, natural
  gas, ethanol
• 4-stroke vs 2-stroke
• Compression ignition (CI) - diesel, biodiesel

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Alternative technologies for powering motor
vehicles (Faiz, Weaver, Walsh, 1996)

• Electric and Hybrid-Electric Vehicles
• AC or DC motors drive wheels alone or in
  conjunction with IC engine. There is no pollution
  from the electric motor at the point of use
  urban air pollution effectively eliminated.
  Pollution at source of electricity generation may
  still be a problem. However, pollution control
  for large stationary sources is typically easier
  and cheaper than for small moving vehicles.
•  Challenges cost, range, performance
• However, already proven in small niches,
  attracting RD

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Electric vehicles

• Continuous electric supply
• Trolley buses or trams supplied by overhead
  wires,
• electric rail transportation systems
•  
• Stored electricity
• Battery powered vehicles, the electricity may be
  generated through hydro, nuclear, or fossil fuel
  combustion
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• On-board generation
• Fuel cells provide the electricity from
  hydrogen, or hydrocarbons stored on-board

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Hybrid-Electric vehicles

• Hybrid an IC engine provides steady power at
  base load, optimized for efficiency and minimum
  emissions, electric motor provides the power for
  accelerations and heavy loads.
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• Regenerative braking Kinetic energy of vehicle
  converted to electric energy instead of heat

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MOTOR VEHICLE EMISSIONS

• Regulated (criteria air contaminants, CAC)
• CO, NOx, NMHC, PM
• Non-regulated
• Individual (speciated) HCs
• carbonyl compounds (alcohols, aldehydes, ketones)
• Air toxics, e.g. benzene, toluene, ethylbenzene,
  1,3,butadiene, formaldehyde, acetaldehyde
• CO2 (i.e. fuel economy)

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MOTOR VEHICLE EMISSIONS

• Exhaust (tailpipe) (CO, NOx, VOC, PM)
• Evaporative (VOC)
• Resting
• Diurnal heat build
• Hot soak
• Running
• Refuelling

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Measures for the abatement of air pollution from
motor vehicles (Onursal Gautam, 1997, Table
3.1)

• Vehicle Targeted
• Fuel Targeted
• Transport Management

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Measures for the abatement of air pollution from
motor vehicles (Onursal Gautam, 1997, Table
3.1)

• Vehicle Targeted
• Emission standards and related measures for new
  vehicles
• Emission standards
• Certification
• Assembly line testing
• Recall
• Warranty
• Emission standards and inspection programs for
  in-use vehicles
• Emissions restriction on imported vehicles

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Measures for the abatement of air pollution from
motor vehicles (Onursal Gautam, 1997, Table
3.1)

• Fuel Targeted
• Gasoline standards
• Lead
• Volatility
• Benzene and aromatic hydrocarbons
• Reformulated gasoline
• Oxygenated gasoline
• Diesel fuel standards
• Sulfur
• Cetane number
• Aromatic hydrocarbons and density
• Alternative fuels (CNG, LPG, methanol, ethanol

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Measures for the abatement of air pollution from
motor vehicles (Onursal Gautam, 1997, Table 3.1)

• Transport Management
• Driving bans
• On-street parking and trading restrictions
• Traffic priority for buses
• Ride sharing
• Staggered work hours
• Speed limits and other traffic management
  measures
• Land use planning and controls

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VEHICLE TYPE SPECIFICATIONS
Indication of Environmental Impacts of the traffic
TRAVEL DEMANDS
VEHICLE ENERGY, EMISSIONS MODEL Submodels for
estimation of fuel use and pollutant generation
rates for specified vehicle types under the given
traffic conditions
TRAFFIC MODEL Simulation, estimation of levels of
traffic flow, travel times, delays and congestion
in study area, over nominated time period
POLLUTANT DISPERSION MODEL Simulation, estimation
of area-wide pollutant levels
METEOROLOGICAL CONDITIONS
NETWORK CONFIGURATION
TOPOGRAPHY AND BUILT ENVIRONMENT DATA