CO2 Filters for Automobiles
Why cannot an automobile muffler be a CO2 filter
(http://www.newton.dep.anl.gov/askasci/chem03/chem03769.htm) that is
replaced every 15,000 miles? I know cost may be a factor, but there
can be a tax deduction or some way to make this feasible. I have
never heard of anyone even trying this.
The main reasons are weight, cost, and effectiveness. First, the filters are
expensive -- and lithium is not the safest stuff in the world either. The
filters weigh a lot, and would cause your car to get significantly worse gas
mileage, causing you to burn more fuel. Moreover, car exhaust has many other
harmful substances in it (like SOx and NOx) that the lithium filter does not
clean -- and these pollutants would be increased due to the decreased gas
mileage. Pollutants and particulates also serve to foul these filters much
faster than in their current applications (e.g. submarines), so they would
not work as long as they could without fouling. Considering all these
problems, and with so many other sources of CO2 in the world (power
generation, industrial combustion, agriculture, etc.), I would guess
scientists and policy makers have determined that investing in LIOH filters
is not the most effective use of money to reduce CO2.
I bet you could get a better, and more quantitative answer (mine is largely
speculation) from the filter manufacturers themselves -- google "LiOH CO2
filter" and you can find contact information (I do not want to post it here). See
what the real experts say! For instance, how much do they weight? Cost? How
long could they last? Etc.
Hope this helps,
The problem is mass. Every gallon of gasoline, when burned completely,
produces about 8 kilograms (17 pounds) of carbon dioxide. How often do
you fill up your tank? How many gallons of gasoline are in a fill-up?
How many gallons of gasoline are consumed in 15,000 miles of travel?
How much would that weigh to carry around with your car? How much LiOH
would be needed to trap the carbon dioxide produced by burning that much
I do not think a tax deduction would make this feasible. Logistically,
you would need to get rid of carbon dioxide produced at least as often
as you purchase gasoline, not every 15,000 miles!
Richard Barrans, Ph.D., M.Ed.
Department of Physics and Astronomy
University of Wyoming
I am not familiar with the industrial process and cost for the production
of lithium hydroxide. I do know that it is not a naturally occurring compound
and is produced from brines containing lithium, usually in the form of lithium
carbonate. This means that in order to produce lithium hydroxide from lithium
carbonate an expenditure -not only of money, but also of energy (electricity)-
would have to be made. If we consider that lithium hydroxide makes for a good
carbon dioxide scrubber because it is very reactive, I can only surmise that
it takes quite a bit of energy to produce it. As such, I imagine that the
environmental cost of producing the electricity/energy needed to make lithium
hydroxide (not to mention the packaging and delivery of the product) would
offset the gains in getting rid of carbon dioxide from emissions.
Greg (Roberto Gregorius)
The reason you have not heard of anyone trying to put a CO2 "filter"
on a car, is because it unfortunately is completely impractical. For
every gallon of gasoline that is burned, there is about 19 pounds of
CO2 produced. A typical car whose gas tank holds around 15 gallons of
gasoline, will produce 285 pounds of CO2 each time it uses a tank of
gas! That means that a CO2 filter must absorb that 285 pounds of CO2,
for every single fill-up! This would require a huge "filter", that
would need to be changed at every fill-up.
As you can see, this is clearly not practical! But the even if it
were, the problem remains: what would you do with all the trapped CO2?
I assume your question results from your concern that manmade CO2 is
claimed to cause global warming. Interestingly, there are many eminent
scientists who have convincing evidence that this is simply not true.
You might be interested in reading the report published by the
Nongovernmental International Panel on Climate Change (NIPCC) that is
titled "Nature, Not Human Activity, Rules the Climate". This report
does a good job of addressing many of the hysterical claims you may
have heard. Here is the link... it is a long report, but very
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Update: June 2012