Crispin,
Thank you. Well stated.
One question I have is about scale. A TLUD stove or 1000 of them together are still small. But would a full size Kon Tiki flame-cap kiln (or 100 of them) alter the scenario that you describe? I am asking for your opinion, because there never have been 100 large flame-cap kilns operating together, so measured results are not possible. And consider that they could be well operated (no winds) vs. poorly operated (windy day with damp fuel). In other words, would scale up in very large numbers alter your statements?
With respect for alternative explanations, or for some confirmation, I hope that some who are more informed than I am (the chemist types) to make comments. Also, there should be opportunity for those who published papers (or the peer reviewers) to respond. I hope that Hans-Peter might comment on this aspect.
To All: Please note, we seek clarification, not to make one person correct and another person incorrect. The instruments for measurement can give sufficient rationale for some statements.
On the other hand, if this large discussion about methane-during-char-making is essentially concluded without much more discussion, then your (Crispin’s) comments will be circulated and saved and quoted in subsequent discussions about PyCCS and climate impact. Let’s get it right, as best we can.
Note: As I was writing the above, an excellent additional message was posted by James Joyce. I have appended that message below after the one by Crispin.
Paul
Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email: psanders@ilstu.edu Skype: paultlud
Phone: Office: 309-452-7072 Mobile: 309-531-4434
Website: www.drtlud.com
From: Crispin Pemberton-Pigott <crispinpigott@outlook.com>
Sent: Saturday, February 23, 2019 3:38 PM
To: Anderson, Paul <psanders@ilstu.edu>; d.michael.shafer@gmail.com; biochar <biochar@yahoogroups.com>
Cc: Stove Discussion <stoves@lists.bioenergylists.org>; Hans-Peter Schmidt <schmidt@ithaka-institut.org>; Kathleen Draper <kdraper2@rochester.rr.com>; Hugh McLaughlin <wastemin1@verizon.net>
Subject: Re: [biochar] Methane from char-makers [1 Attachment]
Dear Paul
Since you asked:
Measurement of methane is done using a CxHy detector (which burns it, if it is cheap, makes it glow if it is expensive). Such a device is in the NDIR detector of the 500 and 700 series of ENERAC combustion analyzers. They measure CO2, CO and CxHy with the same cell.
The main point is that the exact molecule sought is not accurate, it is "centered’. This means the detector is set to report CH4 (which is C1H4 and thus a CxHy) in the centre of its detection range. You could have it set to C2H6 if you wanted. It will report "CxHy" but it is really the combination of several different gases with the methane reported mostly.
So the detection of methane accurately is not really available in small, inexpensive devices.
The numbers you cite for the CO2e of methane are unusually high. There is extremely little methane in the atmosphere inspire of thousands of points of leakage of natural gas (seeps) into the atmosphere. That low value is because it is quickly converted to CO2. Further, there a host of critters that take it directly for food.
The idea that charcoal making could produce enough methane to be detectable against the huge natural leakage is far fetched. There is a large cloud of detectable methane over all tropical forests created by rotting wood. That is far more than could ever be produced by turning the wood waste into charcoal.
Anytime you want to paint some scary scenario you should force people to put numbers on it so it can be viewed in perspective. It takes place in a context where there are huge natural processes in place.
Taken together, turning wood into charcoal or cooking with wood waste and making charcoal, in the context of domestic cooking cannot meaningfully dent anything.
The focus should remain on delivering effective and appreciated cooking services at low cost. To a certain extent, but not obsessively, the memes about charcoal being the enemy of the environment should be countered with realistic quantification and the promotion of modern science and engineering. Aircraft engineering and cell phone technologies get modern science behind them, why not domestic fuels?
Thanks for raising awareness
Crispin
********************
|
Here is the message from James Joyce that also adds valuable content: In terms of measuring CH4 emissions, thought I would mention that we found nearly a decade ago that CO (carbon monoxide) was an reliable indicator of combustion efficiency in the emissions control stage of our systems. We compared VOC, CH4 and HC readings to CO readings. CO is one of the last gases to “go”, with an autoignition temperature of 690 deg C compared to 540-600 deg C for methane, depending which reference you use. Most other species have an autoignition temperature in in the range of 350 to 500 deg C. CO is relatively cheap to analyse for using a chemical cell meter like a https://www.testo.com/en-US/testo-310/p/0563-3100 . We find that CO readings less than 200 ppmv (at less than 10% O2) indicate effective destruction of all hydrocarbon species (i.e. >98.5%). Obviously is important to take the readings where you are not getting lots of air dilution, which could be hard for a stove. We find that thermal oxidation of biomass off-gas for 2 seconds residence time at more than 850 deg C can yield CO readings as low as zero. That probably can’t be achieved in flame cap devices due to radiant heat losses. All I can suggest is to achieve temperatures exceeding 600 deg C in the flame cap for as long as possible. I think high double wall sides would help in this regard. If the flames are escaping from the stove or flame cap kiln they will almost certainly be releasing more unburnt hydrocarbons than if they are contained within a sidewall, because when they escape they are rapidly quenched. ********** [ end of message by James Joyce ]********** Sent: February 23, 2019 12:49 PM Cc: stoves@lists.bioenergylists.org; schmidt@ithaka-institut.org; kdraper2@rochester.rr.com; crispinpigott@outlook.com; wastemin1@verizon.net Subject: RE: [biochar] Methane from char-makers [1 Attachment] |
Michael, Hans-Peter (HPS), and all,
1. Several days of messages. The chemists and testing-experts have not replied (yet).
2. HPS has provided two publications that indicate methane, but there are no “replications” that confirm nor deny. Basically, we have very little info.
3. This thread of discussion started because HPS mentioned significant methane from Kon-Tiki (and by association, other flame-cap devices/ combustion).
4. The question remains: Is methane is so important that methane emissions from char-making could negate (cancel, or even be worse than char) the impact of PyCCS (that includes sequestration of carbon as biochar)?
5. If this is true, then this could shatter the prospects for PyCCS. We cannot sweep this under the table. It must be understood. There is a difference between knowing the impact (or lack of impact, so we can forget about this) versus just dropping the topic as if it perhaps doesn’t matter (or that it is contrary to what we want to believe).
6. I do seriously question whether TLUD stoves (all or most of them) emit methane of consequence, versus the published results about stoves that are reported to be TLUDs but do we know for sure and what fuel was used and if operated correctly.
7. What do Jim Jetter and Tami Bond (both are not yet receiving these messages) and Hugh McLaughlin and Crispin PP and others say? If in fact they did test for methane? Do we reach out to the authors of the publications that HPS provided? I hope that HPS can assist further.
I think this topic should be of highEST interest to the IBI and USBI and others. Please assist.
Paul
Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email: psanders@ilstu.edu Skype: paultlud
Phone: Office: 309-452-7072 Mobile: 309-531-4434
Website: www.drtlud.com
From: d.michael.shafer@gmail.com <d.michael.shafer@gmail.com>
Sent: Saturday, February 23, 2019 7:48 AM
To: biochar <biochar@yahoogroups.com>
Cc: Discussion of biomass cooking stoves <stoves@lists.bioenergylists.org>; Schmidt, Hans-Peter <schmidt@ithaka-institut.org>; Kathleen Draper <kdraper2@rochester.rr.com>; Anderson, Paul <psanders@ilstu.edu>
Subject: Re: [biochar] Methane from char-makers [1 Attachment]
According to the EPA, the GWP or Global Warming Potential, of methane is 25.
As for emissions, I am personally surprised by any claim that TLUDs emit methane. The entire point of a good stack is to encourage methane to burn at a high temp to break down other GHGs. Certainly none of our emissions tests has registered any CH4.
Out here it is nigh on impossible to get a closed room for testing emissions from a trough or trench. (Thai universities see no interest in uncompensated research in the public good.) The water wrapped methane molecules strikes me as improbable, although I think that the suggested risk to the climate is so great that someone needs to re-run these emissions tests immediately.
M
On Thu, Feb 21, 2019, 9:40 PM ‘Anderson, Paul’ psanders@ilstu.edu [biochar] <biochar@yahoogroups.com> wrote:
[Attachment(s) from Anderson, Paul included below]
To all,
The message from Hans-Peter (HPS) is important about emissions from cookstoves AND from char-making devices. The focus is on methane emissions. Some comments, based on a rapid look at the 2 articles attached, which should be studied by the chemists and emissions specialists in our groups.
1. Why are the stove tests not including methane emissions results? (be sure Jim Jetter sees this.)
2. HPS says methane is 100 times worse than CO2, but others say 25 times worse. Which is it?
3. Major comment by HPS: “methane molecules get wrapped by arising water vapor which prevent its combustion.” Correct or not? Can it be explained more fully? And conclusion would be to use very dry fuel, right? (meaning changing our stoves?)
4. I take issue with one comment from table 4 on page 12 (of 16 in Kon Tiki article) about disadvantage of TLUD stoves: “Too small to generate larger amounts of biochar.” THAT statement is the perspective of a SINGLE stove. But when they are used by the thousands, each 1200 TLUD stoves produce about one ton of char/biochar EACH DAY. 36,000 in West Bengal are producing about 30 tons per day, every day, and have been doing so for a few years, and will continue. On a worldwide scale today, that much charcoal is probably more than that of all the flame-cap devices combined on a daily basis. (That last statemen can be challenge if anyone has and data.)
AND the heat energy is not being wasted when TLUD stoves make charcoal. Although the comment in the table overlooks the importance of “scale by number” (instead of “scale by size”), I am glad that the TLUD stoves were at least mentioned in the report and Table. That is progress over being totally ignored.
I hope that there is substantial discussion about the methane topic.
Paul
Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email: psanders@ilstu.edu Skype: paultlud
Phone: Office: 309-452-7072 Mobile: 309-531-4434
Website: www.drtlud.com
From: Schmidt, Hans-Peter <schmidt@ithaka-institut.org>
Sent: Thursday, February 21, 2019 12:29 AM
To: Anderson, Paul <psanders@ilstu.edu>
Cc: Kathleen Draper <draper@ithaka-institut.org>
Subject: Re: Webinar comments by Hans-Peter
Hi Paul,
Please find attached our paper on low tech pyrolysis emissions. The CH4-emissions of TLUD and Kon-Tikis are in the same order. Optimization of gas combustion and especially the use of dry feedstock can greatly reduce CH4-emissions of both. CH4-emissions of forest wild fires are in the some order as optimized Kon-Tiki (see the other attached paper). In field burning of harvest residues produce more methane especially when the residues are humid as is often the case.
The quantity of emitted methane may not look high but as the Global Warming Potential (GWP) of methane is about 100 times that of CO2 in the first 20 years, the climate effect of rather low CH4-quantities is already considerable.
The problem with methane in all low-tech pyrolysis systems is that methane molecules get wrapped by arising water vapor which prevent its combustion.
Be well, Hans-Peter
Von: "Anderson, Paul" <psanders@ilstu.edu>
Datum: Donnerstag, 21. Februar 2019 um 04:25
An: "Schmidt, Hans-Peter" <schmidt@ithaka-institut.org>
Cc: "biochar@yahoogroups.com" <biochar@yahoogroups.com>
Betreff: RE: Webinar comments by Hans-Peter
Hans-Peter,
Thank you.
There was no attached graph. Please send.
I am assuming that you are not subscribed to the Biochar Listserv because you do not send replies to that address. So I am forwarding your very valuable comments to the Biochar listserv. More comments are below.
Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email: psanders@ilstu.edu Skype: paultlud
Phone: Office: 309-452-7072 Mobile: 309-531-4434
Website: www.drtlud.com
From: Schmidt, Hans-Peter <schmidt@ithaka-institut.org>
Sent: Wednesday, February 20, 2019 6:01 PM
To: Anderson, Paul <psanders@ilstu.edu>
Subject: Re: Webinar comments by Hans-Peter
… considering that 40 t DM of biomass per ha is what can be expected in tropical carbon farming systems, the 1500 t of biomass necessary for one standard size E-pyrolysis would need about 40 ha. And even when they do not achieve those numbers in productivity in the first years, with 100 – 200 ha there would be enough biomass per village. In the tropics, this is more or less year around, and the machines can work in continuous processes.
[PSA>>] The above is a valuable statement. DM is “dry matter”, right? Just knowing about 40 t/ha/year would require 40 ha, and then to have extra, allow up to 100 or 200 ha. 100 ha is NOT a very big area; it is only 1 sq km.
So a safe easy statement is that there can be sufficient biomass to produce 1 t of char per day for a year from a area the size of about 1 sq km.
??? Did I say that correctly? We do not want to be saying things that we later need to retract.
???? Maybe others who are in the tropical settings (Thailand, Uganda, etc.) could comment about this.
The US$ 50.000 estimate are based on our experimental E-Pyrolysis data, the Pyreg 1 t BC per day systems and experiences with other rotary kiln systems.
[PSA>>] I looked up the Pyreg rotary kiln. Nice video of a small model at
https://www.youtube.com/watch?time_continue=138&v=Rok9a28IJqQ
???Where is there some info of a larger unit that does 1 t BC per day? Or was that a calculated estimate of scale-up? Either way, that is a good starting point.
It is only an estimate but I do not see any that may increase the material and construction cost beyond 50.000 when it enters serial mass production. And I also think that 50.000 would be a kind of limit for investors to start upscaling.
[PSA>>] I agree. The $50,000 is not a trivial amount and could be the limit for investors. And that is ONLY based on when serial mass production is possible.
??? Statement: What the world needs is a 1 t of BC per day system that costs only $25,000. Is that a good goal or “dream”??? Would that price make the production of biochar become a major factor quickly??? I would like several people to comment about this. Not just Hans-Peter has answers. Comments from all are appreciated.
The methane emissions shown in the graph are based on our Kon-Tiki paper (attached). The data are even much worse when the feedstock is not completely dry. We are going to publish a paper about it within the next months.
[PSA>>] As said before, please send the graph. I really did not associate methane with burning of biomass. I need some instruction. Does an open fire (bonfire or campfire or 3-stone fire) put out considerable methane emissions? The testing of cookstoves does NOT have a methane concern!!!! So is it something about the flame-cap of the Kon-Tiki and other open cone kilns that “causes” the methane to be created and to escape?? Please help with this question. I am still not understanding about methane for such fires.
[PSA>>] Paul
Best, hp
Von: "Anderson, Paul" <psanders@ilstu.edu>
Datum: Mittwoch, 20. Februar 2019 um 23:57
An: ‘Hans-Peter Schmidt’ – Switzerland – Nepal <schmidt@ithaka-institut.org>, "biochar@yahoogroups.com" <biochar@yahoogroups.com>
Cc: "Anderson, Paul" <psanders@ilstu.edu>
Betreff: Webinar comments by Hans-Peter
Hans-Peter,
Just wondering, why do you think that the 1 t/day of char production would be a size that would be appropriate for villages? We are discussing developing countries. Would this be expected year round, or maybe only seasonally for 2 to 5 months (and then idle)?
And where did the $50,000 price per pyrolyzer installation come from? I am content if you say it was just a convenient number, but maybe you have some basis for it.
*********
Another question:
I was surprised by your comment about the (relatively) high emissions of methane from the Kon Tiki (and other) flame-cap charmakers. Any links to reports about this? Why methane? I would have more easily believe high PM or CO.
Paul
Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email: psanders@ilstu.edu Skype: paultlud
Phone: Office: 309-452-7072 Mobile: 309-531-4434
Website: www.drtlud.com
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