Re: Carbon monoxide

["L. R. Cartwright (Larry)" <physics@SCNC.CPS.K12.MI.US>]

#1) Carbon monoxide is produced when carbon rapidly combines with
    a limited supply of oxygen:  2C + O2 --> 2CO

#2) If there is lots of oxygen, the CO will combine with more O2
    to produce carbon dioxide:  2CO + O2 --> 2CO2

If you burn *anything* in an enclosed space, you get #1 but not #2.
There's nothing special about gasoline.  The same thing happens with coal,
wood, charcoal, kerosene, diesel oil, methane, propane, whatever.

If you burn fuel in an engine, you get #1. By time the CO gets out of the
exhaust pipe to a further supply of O2, the temperature is too low for #2
to occur.  Hence vehicle exhaust is CO-rich.

CO is stable, in the sense that the C and O will not come apart easily.
It is however quite reactive, explosively so.  And it has an incredible
affinity for the hemoglobin in your blood; in an environment with CO and
O2 mixed, hemoglobin preferentially bonds to the CO which is why it can
kill you even in fairly low concentrations.

Historical note:  The gas piped into homes in the late 19th and early 20th
century was CO, which ran the gas lamps and refrigerators and ranges of
the day.  Gas companies manufactured the stuff by burning wood or coal
with a restricted oxygen supply.  Gas companies don't make gas anymore,
they refine it; it's CH4, C2H6 and other liquified petroleum gases.

Here in the frosty North Central region a few people CO themselves to
death every winter by using oil burners, charcoal grills, propane stoves
indoors; or by having improperly vented or leaky furnaces.

In terms of "greenhouse effect", CO doesn't seem to be any worse than CO2.
But as a pollutant, CO can be pretty nasty because of its reactivity.  It
has a tendency along with nitrogen oxides to synthesize some really foul
molecules.  Smog.

Best wishes,

Larry

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright
Physics, Physical Science, Internet Teacher
Charlotte High School, 378 State Street, Charlotte MI 48813
<physics@scnc.cps.k12.mi.us> or <science@scnc.cps.k12.mi.us>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On Mon, 16 Nov 1998, Jim Green wrote:

> A non-science friend wonders as follows:
> Why do we seem to get more carbon monoxide when gasoline burns than when
> anything else does?  Do we get it when coal burns?  Do we get as much?
> Is carbon monoxide stable?
> I am ruminating on greenhouse cases.
> What would you tell him?
> Jim Green
> JMGreen@sisna.com
> http://users.sisna.com/jmgreen