Environmental Impacts of the Automobile Flashcards
Environmental impacts due to automobiles are uniquely related to engineering design decisions that determine the release of pollutants.
False - land use decisions (construction of roads, parking lots) are also related.
Improvements in fuel economy have lead to actual, measurable decreases in CO2 emissions.
True.
What are the three (types of) gases emitted by automobiles, besides CO2?
Hydrocarbons (HC), nitrogen oxides (NO), and carbon monoxide (CO).
Which of the 3 (types of) of non-CO2 gases emitted by automobiles lead to the formation of photochemical smog?
HC and NO gases.
Name a chemical compound that falls under the umbrella of photochemical smog?
Ozone.
Energy from what source causes HC and NO to react and form photochemical smog?
Heat from the sun.
Which of the 3 (types of) non-CO2 gases emitted by automobiles is also known as a volatile organic compound (VOC)?
Hydrocarbons (HC).
Although photochemical smog is made up of a number of chemical compounds, it is measured as an equivalent of which specific compound?
Ozone.
When/why do automobiles emit CO and HC?
Due to the incomplete combustion of fuel.
Hydrocarbons, when not the product of incomplete combustion, is emitted in what form?
As gasoline vapors.
Where do HCs come from when in the form of gasoline vapor (3)?
Hot engines, from the venting of the engine crankcase, and from the venting/refilling of fuel tanks.
Why do nitrogen oxides form during combustion?
Combustion supplies high temperatures that allow NOs to form by chemical reactions between nitrogen and oxygen in the air.
In what type of areas does the automobile’s 3 non-CO2 air pollutants pose the most significant environmental problems?
Urban.
Overall vehicle usage can be tracked by total vehicle-miles of travel (VMT) per year. How is VMT calculated for a given year?
(miles travelled per vehicle) X (total number of vehicles).
Actual on-road emissions are generally higher than federal test cycle values.
True.
Why are NO2 emissions underestimated by federal test cycle values?
Higher average speeds cause higher NO2 emissions.
Why are overall emissions underestimated by federal test cycle values?
Improper maintenance or tampering with emission control systems.
Why are HC & CO emissions underestimated by federal test cycle values?
Cogged air filters and dirty spark plugs.
Why do light trucks (as opposed to regular cars) have increased environmental impact?
Heavier vehicles consume more gasoline and emit more CO2, HC, and NO, per mile of travel.
What record percentage of the market did truck SUVs reach in model year 2021?
45%
What record percentage of the market did pickup trucks reach in model year 2021?
16%
What social phenomenon has offset the improvements made to each vehicle type’s fuel economy?
The trend away from sedans/wagons and towards truck SUVs & pickups.
Currently, most motor vehicles worldwide are powered by what two forms of fuel?
Gasoline and diesel.
Refined into gasoline, diesel oil, and jet fuel, petroleum supplies about what percentage of the energy used for all forms of transportation (in the US)?
90%
Chemically, petroleum and its derivative fuels consist mainly of what two types of compounds?
Carbon and hydrogen compounds.
Which gas is the natural product of combustion?
CO2
Through what part of the car is CO2 released into the atmosphere?
Exhaust pipe.
For every mole of octane, how many moles of CO2 and water vapor are produced?
8 moles of CO2, 9 moles of water vapor.
What is the chemical formula for octane?
C8H18
What programs have significantly alleviated the solid waste problems of discarded automobiles?
Recycling and reuse programs.
How are non-recyclable car parts typically disposed?
Burial in a landfill.
Today’s solid waste from automobiles reflects the materials used in cars that were manufactured an average of how long ago?
Eight to nine years ago.
As the mix of materials used in auto
construction changes over time, the ability to reuse or recycle those materials also may change.
True.
The environmental contaminants from automobiles can be categorized as either HC/NO/CO emissions or solid waste.
False - cars have and still emit lead and CFCs into the atmosphere.
The population of older vehicles that use leaded gasoline constitutes the first largest source of U.S. lead emissions.
False - second largest, according to the EPA.
Why do many non-US countries continue to use leaded gasoline?
Lower cost.
How do automobiles emit CFCs?
Due to CFCs used in automotive air conditioners (pre-Montreal Protocol enforcement).
Air conditioning systems in cars that utilize CFCs don’t necessarily emit them - how do they end up in the atmosphere?
Via leaks in the air conditioning system over the life of a car.
Further production of CFCs has been phased out in the United States and other industrialized nations.
True.
Generally, what is the last remaining (legal) source of CFCs?
Capture and recycling of the existing stock of CFCs will be the only source of these chemicals until they are finally depleted.
What are the 4 methods by which to design cleaner cars?
Designing for energy efficiency, reducing pollutant formation, alternative fuels, and alternative vehicles.
Why is the impact of CH4, N2O and CFCs so significant, if their emissions are small in comparison to CO2?
They have a higher global warming potential (GWP).
What 5 parts of a car in particular have been redesigned to improve combustion efficiency and reduce NO formation?
Engine manifolds, cylinders, pistons, valves, and ignition system components.
Besides modified forms of gasoline, name 4 alternative automobile fuels.
Diesel, methanol, ethanol, and compressed natural gas.
Which alternative fuel is produced from biomass?
Ethanol.
Alternative fuels promise to reduce what type of automotive emissions in particular?
Smog-forming automotive emissions.
Name two types of alternative vehicles.
Electric and hybrid.
Electric vehicles (EVs) have a battery instead of a gasoline tank, but still make use of an internal combustion engine.
False - they have an electric motor instead.
Plug-in hybrid electric vehicles (PHEVs) have a battery, a gasoline tank, which both feed an internal combustion engine.
False - the battery feeds an electric motor.
