Energy and Electricity - Introduction to Carbon Capture and Sequestration - page 36

Paving the way for change
Question: If we convert all of the CO 2 emitted by a car over its lifetime into limestone
and use this limestone to pave someone's yard, what is the surface area we can cover?
How does this differ depending on whether the car is a Prius or Hummer?
Solution: Miguel Angel Garcia Jr., Eunice JiYoung An, Joshua Deitch, and Anton Mlinar.
Typically, cars run on internal combustion engines that rely on the com-
bustion of fossil fuels to turn chemical energy into mechanical energy. As
a by-product, carbon dioxide is produced and released as exhaust into
the atmosphere. But there are alternatives to this process. The two meth-
ods which have garnered the most attention are the hybrid electric and
electric vehicles. By relying either partially (hybrid) or almost wholly (EV)
on electric power, these vehicles reduce the combustion of fossil fuels for
power, thus reducing carbon emissions. Due to their high gas mileage
and decreased emissions, many people are hailing hybrids (like the Prius)
and new mid-sized electric vehicles as viable weapons to battle climate
change.
There's no doubt that hybrid and electric vehicles represent some
reduction in carbon emissions compared to gas-guzzling alternatives
like the Hummer, but to what degree? Even if the electricity supplied to
a EV is carbon free (or carbon neutral), there is still a significant energy
cost in the production of these hybrid and electric vehicles, and thus
the carbon savings gained from replacing internal combustion engines
could be offset by emissions related to production. Also, there are
many concerns over the batteries used by these cars. Not only is bat-
tery manufacturing energy-intensive, but considerable pollution results
from the mining of essential rare earth metals that it involves. To deter-
mine the true environmental impact of alternative engines for transpor-
tation, we compared emissions from production and use between the
Hummer and the Prius. To make it more interesting, we represented
these values in terms of surface area of limestone that would be cre-
ated by each, assuming we could capture all of the carbon emissions
in this format.