[at-l] Trail-related engineering stuff

[spiriteagle99@xxxxxxxxxxx (Jim and/or Ginny Owen)]

Shane wrote:
>Nope.  I been doin' my homework.
>
>LPG emits 15 times more CO2 (carbon dioxide) per kg than wood, and kerosene
>nearly 10 times as much.  That's not surprising, since LPG >and kerosene
>are more energy 'concentrated' than wood.  By heat energy, kerosene
>provides 5.25 times the heat energy as the same weight of dry wood.
>
>BUT, for that same amount of heat, that kerosene produces about twice as
>much CO2 as wood for the same heat energy.

Since Shane did his homework, I felt compelled to do mine.  <G>
My only comment on the above numbers is that they come off a page that's
designed to sell wood stoves.  Draw your own conclusions <G>

Next - I'll apologize to Shane - I wasn't intending to be insulting
regarding his ability to count.  But there are a couple confusion factors in
counting this stuff.

Anyway - Shane shamed me into coming up with real numbers here - so ---
I dug out the numbers for several different fuels and kicked around some
equations. Following are the results - in terms of how much CO2 is produced
by each. I'll happily answer questions, but preferably privately since the
results may bo on topic but the process wouldn't be.

Initial conditions - Ginny and I use 2.5 oz of white gas per day when we're
using the Whisperlite Internationale. That means we use 2970 BTU per day for
cooking purposes.  That's an overall number and includes any inefficiencies
because it's what gets us two hot meals per day. I used 2900 BTU/day  as a
base number,  then used the specific gravity and published numbers for heat
value and carbon dioxide production (carbon coefficient) for the particular
fuel. The numbers come with some caveats - we'll get to that later.

The results --
Gasoline - I used numbers for regular unleaded - couldn't find numbers for
white gas.  I HAVE used regular unleaded for long distances - it produces
more soot than white gas but works just fine. The bottom line here is that
it produces 0.514# CO2 per day.

Kerosene - DON'T use this in a white gas stove without changing the jet over
to a specific kerosene jet.  It also produces some soot, but not as much as
everyone thinks.  In a stove, it does pretty well.  And for the conditions I
used (2900 BTU per day), it produces 0.511# CO2 per day.

Methanol - also know as Heet or, even better, denatured alcohol.  I had to
use numbers that aren't as reliable as I'd like, but will work for an
approximation.  This is a relatively low-energy fuel, requiring nearly twice
the fuel weight of a gas stove and it would produce 0.797 # CO2 per day.

Propane - is a high-energy fuel and would produce 0.409 # CO2 per day.

Wood - assuming dry, well seasoned wood would produce 0.934 # CO2 per day.

A couple caveats - first that these are theoretical values that will vary
due to the conditions under which they're used.  Wet wood , for example,
will produce more because part of the energy goes into evaporating the
water.  Second that white gas, propane and kerosene are "controllable" in
that (in the absence of major stove malfunction) they can (and should) be
turned off when not in actual use (cooking - or in my case, heating water).
Third, methanol and wood are not "controllable" in that once started they
must be allowed to burn out, thus producing more combustion byproducts than
was calculated here.  That is, unless you want to dump sand or water in the
works.  But - DO NOT - REPEAT - DO NOT dump water on an alcohol fire unless
you want it to spread.

Of course, none of this is terribly significant in the great scheme of
things.  And there are other, far more important factors in stove selection
- including personal preference.

This whole exercise was, first, a matter of curiousity and second, an excuse
for me to dig out some information and actually calculate something
relatively real.  I won't tell you why that's important to me right now.


>Petroleum distillates cost much more to produce, and have other byproducts
>besides fresh air.  Alcohol, and other biomass distillates, require energy
>AND biomass to produce that far exceeds their value in terms of energy
>gained.  (It's a net-loss proposition.)
>

The only other comment here is that Shane and I will someday have to have a
conversation about that last statement.  Short version is that if it were a
net-loss proposition, then it wouldn't be done on a long term basis.

>
>No, but it does make you a heathen.  As a Minister of the Holy Flaming Zip,
>I can grant you forgiveness but you have to convert now.  This is a limited
>time offer...

Oh, God help us - another evangelizer!!! <VBG>

Let's see, in that last week I've been called a heathen, an unwashed
barbarian - and a few other, less printable things.  Cool.  Means I must be
doing the right things.  <VVVBSEG>


> > Uh - tell me again - which one of us understands what?

>I understand that you're a heathen, your soul sold to Republican Alcohol
>Producers who have subtly slipped the idea into the backpacking community
>that alcohol stoves are fun and easy to build >and use.

Hmmm - I became a Republican so I could vote AGAINST Bush the Elder in the
primary.  Prior to that I spent 25 years as an Independent, and prior to
that I was a registered Democrat.

And alcohol stoves ARE fun and easy to build and use.  Try it - you might
like it.  I resisted for a long time - but resistance is futile, you will be
assimilated.


>you will probably be reassigned to
>spread your anti-wood-burning rhetoric elsewhere.  Probably Mongolia.

Cool - when can I leave?  <G>


>At least that's what the radio-transmitter the government had aliens
>install in my head tells me.

C'mon now - you know the only voices that don't lie are the ones that don't
need the radio ------

>If they send you to Mongolia, can we have a trip report?  I understand that
>some parts of the country are really pretty, and I've always wanted to hike
>there...

Yeah - me too.


>That snow's got you all cabin fevered up, Jim.  Eat a Twinkie and have a
>cigarette.  ;)

Now I know you - the Devil in disguise -- tempting me like that.  <VVBG>

Have a good day - I need to get back to work. Catch-up is tough.
Walk softly,
Jim


_________________________________________________________________
STOP MORE SPAM with the new MSN 8 and get 2 months FREE*
http://join.msn.com/?page=features/junkmail