[Stoves] FW: REQUEST for complete sets of raw data of cookstove tests.
Kevin
kchisholm at ca.inter.net
Wed Apr 24 17:20:02 CDT 2013
Dear Paul
I append my original message, on this thread, below. What leads you to believe that I only equate fuel with wood and trees?
Equally, why do you feel that Crispin only equates fuel only with wood and trees?
In my clip from an excel spreadsheet, I clearly show both Ag. Waste and Stick Fuel stoves in my example, with no prejudice or advantage extended to either. Additionally, I show both "char producing" and "full combustion" stoves, with no prejudice or advantage extended to either. I leave it entirely to the Customer to decide which stove system is best for him.
How is that being unscientific?
Kevin
----- Original Message -----
From: Paul Anderson
To: Discussion of biomass cooking stoves
Sent: Wednesday, April 24, 2013 3:13 PM
Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of cookstove tests.
Dear Crispin and Kevin,
You are happy to talk about Fuel efficiency, and use ENERGY numbers. And then immediately discuss forests being destroyed.
Please get past the equating of fuel with wood and trees. Beating on that drum constantly is unscientific.
Paul
Paul S. Anderson, PhD aka "Dr TLUD"
Email: psanders at ilstu.edu Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.comOn 4/24/2013 9:49 AM, Crispin Pemberton-Pigott wrote:
Dear Kevin
You analysis is correct. When rating the performance of a stove from a fuel use perspective, the chart is correct:
Two stoves are being compared for "Efficiency".
Given facts from Tests:
STOVE A
STOVE B
STOVE C
STOVE D
Nature of Fuel
Ag. Waste
Ag.Waste
Stickwood
Stickwood
Fuel Energy Supplied, MJ
10
15
10
15
Energy to Cooking Pot, MJ
5
5
5
5
Energy in Char, MJ
0
5
0
5
Stove Efficiency, %
50.00%
33.33%
50.00%
33.33%
If someone is interested in the char, it can be reported. What Ron is proposing, to add that heat energy available in the char back into the mix, is akin to considering the energy efficiency to be the fuel efficiency which is precisely what created for us a problem in the first place.
The energy value of the char came from somewhere. Consider a stove that takes 2 tons of forest per year. If it produces ¼ of a ton of forest's worth of energy in the form of char, fine. Say so. But saying so does not reduce the two tons of forest it takes. If you have (as you pointed out) a second stove that can utilise the charcoal, then that can be viewed as a 'system' by all and sundry, but is still does not change the fact that Stove 1 takes two tons of forest each year which is what the reported fuel consumption should be. No smoke and mirrors.
Burying the char as a soil amendment instead of burning it merely takes us back to the two tons of forest per year draw-down and returns it to the environment in an (apparently) inert, solid form.
What has been happening that is wrong, in my view, is that stoves that take off 3 tons of forest per year have been getting credit for taking only one ton and proclaimed to be 'better' and 'more fuel efficient' than a two-ton stove. Plainly this is not the case and the test method has to report the fuel consumption correctly. It is a problem that the UNFCCC methodology does not handle this well because it is being used for CDM trades.
Regards
Crispin
----- Original Message -----
From: Kevin
To: Discussion of biomass cooking stoves
Cc: jetter jim
Sent: Tuesday, April 23, 2013 6:49 PM
Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of cookstovetests.
Dear Paul
(comments below...)
----- Original Message -----
From: Paul Anderson
To: Discussion of biomass cooking stoves
Cc: jetter jim
Sent: Tuesday, April 23, 2013 4:11 PM
Subject: Re: [Stoves] FW: REQUEST for complete sets of raw data of cookstove tests.
Ron, Crispin, Jim and all,
One stumbling point is the difference between the words Fuel and Energy. We cook with fuels. We cook with energy. But a piece (1 kg) of wood (fuel) can deliver 16 MJ of energy if burned to ash or it can deliver (example) 11 MJ of energy PLUS charcoal that represents 5 MJ of energy.
The piece of wood is totally changed in both cases. But in the second case, part of that wood has been transformed into charcoal, which is certainly not wood. Wood consumed is 1 kg. Energy consumed is 11 MJ (with charcoal left over). Two very different results to be reported.
And then there is the case of one kg of agricultural "refuse" that is 16 MJ if consumed totally, or 11 MJ plus charcoal if pyrolyzed, and in NEITHER case was there any consumption of wood. Where deforestation is an issue, stoves that can use (easily use) agricultural refuse need to be distinguished from the wood burners.
# To view the issue differently...
Two stoves are being compared for "Efficiency".
Given facts from Tests:
STOVE A STOVE B STOVE C STOVE D
Nature of Fuel Ag. Waste Ag.Waste Stickwood Stickwood
Fuel Energy Supplied, MJ 10 15 10 15
Energy to Cooking Pot, MJ 5 5 5 5
Energy in Char, MJ 0 5 0 5
Stove Efficiency, % 50.00% 33.33% 50.00% 33.33%
# So, we see that for the same cooking task, Stove A and stove C have the best efficiency, both at 50%
while Stoves B and D also have the same efficiency, both at 33.33%
# Now it is up to the Customer:
IF HE WANTS CHAR, he chooses Stove B if he has Ag Waste for fuel, or stove D, if he has stickwood fuel
IF HE DOES NOT WANT CHAR, he chooses Stove A if he has Ag Waste for fuel, or stove C, if he has stickwood fuel.
# Thats all the Customer needs to know, in order to make the best choice of stove for his circumstances.
Even when the stove testing is conducted with wood as the standard fuel, the test RESULTS need to clearly reveal that wood did NOT need to be burned.
# This is an efficiency test. This is not a test of the merits of using Ag. Waste or Stickwood. The test tests teh stove with whatever fuel is supplied.
In the movies, "No animals were harmed in the production of this film."
For SOME cookstoves, "No wood was burned in the cooking of these meals (or the conducting of these tests)."
# That is an issue above and beyond Stove Efficiency Testing.
What happens to the charcoal (whether burned or as biochar or otherwise lost) should not be the issue.
# The "Efficiency Test" is a measure of "efficiency of utilization of fuel by the device being tested." Regardless of the value of the char production, the simple fact is that the char represents non-utilization of the fuel supplied to the device being tested. The fact that the char could be used in another stove, or could be used as Biochar for soil Application is another issue entirely. If we take credit for the fact that the char could be used elsewhere in another system, we could really confuse the issue if we claim such things as :
" 20% of the supplied energy was lost through the sidewalls of the stove but it heated the kitchen beneficially, so I think the Stove Efficiency should be increased by 20%
or
" I am using the stove to heat a small enclosed greenhouse, and I am venting the stack gases inside to use the CO2 by the plants. Since the fuel contained 50% carbon, and it was burned to completion, I claim 100% 'Efficiency of utilization of the fuel."
# External, or "subsequent usage benefits" are issues outside the scope of "efficiency of use of fuel by the device being tested.
Best wishes,
Kevin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130424/da271ad9/attachment.html>
More information about the Stoves
mailing list