Post on 20-Apr-2023
Chapter 9
Automobile Emissions Controls
Stationary Emissions Control
Cost of Emissions Controls
Thermal Pollution from Energy Generation
Ecological Effects of Thermal Pollution
Cooling Towers
Using Waste Heat
Automobile Emissions Controls
Emissions can be controlled in several ways
Change the fuel used by the car
Change the way that the engine burns the fuel
Decrease the use of cars by subsidizing mass transit
Changing the Fuel
What are other names for methanol, ethanol and compressed gas?
How are they made? Other drawbacks of these fuels?
The Newest Fuel: Nitrogen
Newest alternative fuel
(reported this Monday)
Works by using
decompression of
Liquid nitrogen to
Push pistons and run
The car engine.
No pollutants at all, BUT
Technology not mature.
Changing the Burning ProcessMore efficient cars emit less CO2 per mile traveled.
(In the 1970s, estimated that could run
All cars on ethanol and methanol derived from
Fermented biomass if all cars averaged 60 miles
Per gallon.)
Number is out of date, but at some gas mileage
It is possible to run all cars on renewable sources
Of hydrocarbons.
Amory Lovins: using the best technology:
Could potentially build cars
That get 150 miles per gallon.
Positive Crankcase Ventilation
At the edges of the combustion
Chamber of the engine
(above the piston tops), there is a
thin layer of gasoline that does
Not burn up. This gasoline
Constitutes an air pollutant
(what is its classification?)
To keep gasoline from returning to
The air, this gasoline is recirculated
Back into the combustion chamber.
Exhaust Gas Recirculation
Exhaust gases are
Removed from the
Crankcase and then
Recirculated back into
The carburetor.
Other Pollution Controls
Minimize CO and hydrocarbons by improving burning
Of the fuel.
To improve burning: use leaner fuels and increase
Temperatures in the combustion chamber.
Leaner fuels: means mixture of air plus fuel has more
Air and less fuel.
But leaner fuels increase Nox formation because
Burning is at higher temperatures and more oxygen is
Available to form Nox.
Catalytic converters: help to get around these problems.
They require unleaded gasoline.