ETHOS

Report on TLUD Discussions at the 2010 ETHOS conference
By Christa Roth and Kelpie Wilson
Submitted 8 March 2010

There was a good showing of TLUD technology at the annual ETHOS Stoves conference in Kirkland, WA, USA on January 29-31, 2010. This report covers some of the discussions about TLUDs that took place at conference sessions.

Dr. Paul Anderson, a.k.a., “Dr. TLUD”, made the pitch for TLUDs and biochar throughout the conference. He brought a large collection of 20 different TLUDs. Most were simple homemade devices made from “tincanium” (Dr. Anderson’s Friday evening presentation on the wonders of “tincanium” was delightfully humorous). TLUD designers Art Donnelly, Christa Roth, and Hugh McLaughlin all had stoves on display. Anderson had one example of a mass produced TLUD that is manufactured in India.

About 30 people attended the TLUD community discussion session. To get an overview and discover who had which type of specific interest, the participants were asked to raise hands on which aspects of application of the TLUD principles they were interested in. The following aspects were identified:

• Applications: is the main focus on cooking, biochar, or a combination of both?
• What are appropriate sizes? TLUDs exist for 2 cups, 2 liters, 5 l, 20 l up to 5 gallon, 20 gallon, 55 gallon. The interest in producing biochar is driving design of larger TLUDs.
• Natural draft or forced air. If using forced air, what are the implications of different power sources: grid, Thermo Electric Generator (TEG), battery based electricity
• Emissions (indoor, outdoor, any)
• Fuels (types of fuels, sizes and densities)
• Locations (which continent, urban, peri-urban, rural environments)
• Materials for TLUDs (ceramics, metal)
• What price range is acceptable? (developed country, developing countries)
• What can we as individuals and organizations do to advance TLUD technology?
• What are the future prospects of TLUD technology?

Participants at the TLUD session participants made a list of TLUD features as compared to other stove types such as the rocket stove:

• Makes biochar
• Starts fast, boils water very quickly, and burns a long time on one load of fuel
• Less attention required for fuel input (no continuous stoking of the fuel needed), increasing freedom for the operator/cook
• Fuel flexible – uses small size waste that cannot be burned in other stoves
• Cleaner than other kinds of stoves, with low Black Carbon (BC), Organic Carbon (OC) and CO
• Variety of scales and applications from cooking to metal forging, including barbecue, grilling, frying, heating, lighting
• Lightweight, portable and modular; can use multiple units to control heat output
• Easy and cheap to build from tin cans or sheet steel. Dimensional tolerances are not stringent
• Low temperature operation. Pyrolysis temperatures are below 500 degrees C, resulting in less combustion chamber burnout
• Suitable for fireplaces that are not allowed to burn open fires any longer
• Safe for indoor space heating with flue exhaust
• Can be an inexpensive add-on to existing stoves for specialized applications (e.g. water kettle in addition to a plancha stove) and to take advantage of small sized fuels not suitable for a rocket stove

A few TLUD problems/challenges were also identified:

• Lack of turndown ratio
• Lack of emissions robustness. More emissions on startup and sometimes on shut down.
• Changing fuel form factor when adding new fuel can cause stalling.

The group discussed in detail the following ideas for advancing TLUD development:

Materials: light-weight ceramics are not necessarily needed for insulation of the combustion chamber, unlike in a rocket stove, as for TLUDs the temperature in the fuel bed stays at ambient temperature until the pyrolysis front passes through. Then temperatures get higher. The open flames are not within the combustion chamber but above the fuel bed. The hottest parts of a TLUD stove are the concentrator disk and the bottom of the fire chamber, where the remaining charcoal might be burnt creating high temperatures (if the char is not dumped out and conserved for other use e.g. as biochar). Ceramics are cheap to fabricate, e.g. consumable stove components like the concentrator disk or the bottom plate of the fire chamber. Options for modular stove designs containing ceramic parts to be explored further. A huge gap between standard pottery and industrial ceramics was noted.

Production and Dissemination: Stoves should come as a kit: combustion chamber + pot stand/application + snuffer box for the char to be saved.

Economics of charcoal: The saving of char could become more popular if the produced charcoal were attributed more value (carbon offsets for biochar used in the soil, charcoal fines to be processed into charcoal briquettes, water filters etc.)

Modular advantages: TLUDs excel on high power output, e.g. boiling water, but don’t turn down the power so well. The concept of having a different and/or smaller combustion unit for the simmering stage or replacing the continuous heat addition with a retained heat cooker should be explored further. Modular systems could use a number of TLUD burners under a large pot or grill. If cooking lasts a long time, such as firing a grill at a restaurant, you could replace spent TLUDs with new ones to keep the heat going while you recharge spent TLUD’s with new fuel.

Despite the advantages of the TLUD there are very few stove programs using TLUDs. Here are the ones we know about:

• The BP Oorja stove, now called FirstEnergy, distributed 400,000 units in India, but there exists little feedback on the campaign.
• Phillips had a TLUD stove and planned a major roll-out in India to start late 2009, but no up-to-date info is available.
• Nathaniel Mulcahy of World Stove is manufacturing institutional and household size stoves in Haiti (uses a pyrolytic gasifier technology similar to TLUD); allegedly building over 100 units per day with plans to upscale and add a fuel production unit for grass pellets. This is a very interesting project in the limelight, with high potential to create worldwide awareness. To be observed.

Other than those listed above, there are no projects yet at a major scale. Participants observed that this was a ‘chicken-and-egg’ scenario: Donors only want to roll out ‘already proven technologies’ but nobody apart from major companies like BP or Phillips has the money to do the research needed to prove the technologies. Funding is needed for research to get the combustion chamber to the application stage and to collect user feedback on a major scale.

The group felt there was a strong need to get more experience on the ground building and cooking on TLUDs. In Uganda this year a TLUD-project with World Bank funding will start. Funding has been secured for 2 years. More projects are needed.

What participants committed to do:

• Cook on a TLUD. Several people have been making TLUDs, but very few have been cooking on them. Some people volunteered to use a TLUD for cooking for a given time, like a month, and blog about the experience. More volunteers are needed to do this.
• Create awareness and knowledge about TLUDS.
• Paul Anderson committed to put a TLUD handbook on the web.

Upcoming TLUD events include a Combined Heat and Biochar event in Massachusetts on 9-13 August (contact Paul Anderson for more details) and the annual Stove Camp at Aprovecho, 26 to 30 July. Dean Still, organizer of the Aprovecho Stove Camp has said the camp will focus on the TLUD this year.

From Willie to Richard: A Family of Tincanium Stoves
Paul Anderson,Hugh McLaughlin

A Power Point Presentation presented at the 2010 ETHOS Conference. It is a bit "tongue in cheek."

Enjoy!

Paul
--Paul S Anderson, Ph.D. -- aka Dr. TLUD ("Dr. Tee-lud")
Biomass Energy Consultant with BEF, & Partner in Chip Energy.
Specialist in micro-gasification.
Office & Res: 309-452-7072

The 2010 ETHOS Conference is being held in Kirkland, Washington, on January 29th ~ 31st, 2010.

The 2010 ETHOS Conference aims to expand its reach from previous annual meetings, encouraging participation of Southern partners, international stoves experts, and development specialists with field experience in the transfer of cooking technologies.

2010 ETHOS Conference & Registration on their website

Summary of ETHOS Stove Camp, August 3-7, 2009
Dean Still and Nordica MacCarty

Forty three folks attended Stove Camp this year coming from as far away as Norway, Germany, Honduras, and Mexico. Some people were too busy making stoves to be in the official photo. Paal Wendelbo, winner of the $250 prize for most interesting development, is the white haired gentleman two spaces to Dean’s left. The theme this year constellated around health issues. You can see the presentations and results from Stove Camp by visiting http://www.aprovecho.org/lab/index.php.

Stoves Camp 2009 Group Photo

Stove Camp featured many experiments. We set up a Test Kitchen, in which stoves were tested, making posho (African corn meal mush). Particulate Matter and Carbon monoxide were recorded in both the room air and at the nose/mouth of the cook. We also used a RAD 57 from Masimo to non-invasively measure levels of CO in the cook’s blood before and after cooking. Stoves were also tested under the emissions hood, and practice WBTs were run without emissions measurements. Peter Scott and Dr. Andreatta were successful in creating an aluminum mitad with even temperatures for making injira.

See the attached report for more detail

Finned Pots as a Means of Increasing Efficiency Dale Andreatta, Ph.D., P.E., dandreatta@sealimited.com, February 13, 2009

Executive Summary A pot with heat transfer fins has much greater surface area than pots with no fins. In theory, this could lead to greatly increased heat transfer to the pot for a given stove, and the pot would theoretically improve the performance of the stove under all conditions. While we often concentrate on the stove as the primary element of a cooking system, the efficiency of a stove is mainly determined by the heat transfer to the pot, and designing a better pot would be an easy way to make a more efficient stove. A variety of types of finned pots were built and tested. The best designs were separated out in the lab, using natural gas to simulate a wood flame. Several types of fins can be retrofit to existing pots. The better designs of finned pots performed well over a range of conditions using simulated stoves, and sometimes also with an actual wood burning stove modified to use natural gas to simulate a wood flame. With fins on or near the bottom of the pot the finned pots typically gave around a 1.76-fold improvement in heat transfer. If the fins were on the sides of the pot a greater than 2-fold improvement was achieved. Tests on actual stoves using wood as the fuel generally gave smaller improvements in performance, generally 1.33 or less, corresponding to a 25% or smaller reduction in fuel usage. These tests were done under a variety of conditions with a variety of stoves, including the open fire (3-stone fire). On industrial fuel stoves using kerosene or alcohol, improvements were even less, with the finned pots giving 1.2 fold improvements or smaller. In some tests the finned pot used more fuel than an unfinned pot. The reasons for this wide range of results is not known. It is not recommended that finned pots be pursued as a means of increasing the efficiency of stoves. Better results can probably be achieved with less effort by using skirts around the pot. These skirts could be attached to the pots with optimum dimensions. See attached report presented to ETHOS 2009

ETHOS 2009 Developing World Cooking Stove Conference Charlie Sellers, February 11,2009 This was my third ETHOS (Engineers in Technical and Humanitarian Opportunities of Service – a long name for people who often just call themselves “stovers”), and the Seattle suburbs are as cold as usual at this time of year. ~100 researchers came from around the world to compare notes on stove projects, stove designs, standards and testing procedures, health impacts, other associated appropriate technologies, and so on. More apparent this year was interest in carbon credit funding and biochar (terra preta) applications, and all year long there has been an increased emphasis on refugee camp stoves (and more testing of stoves in the field, versus in the laboratory) so this was more apparent at the conference. There was a raft of new stoves introduced this year, including the new BioLight thermoelectric-powered-fan one for camping and more, the likewise fan powered Lucia Stove from www.worldstove.com (shown with developer Nate Mulcahy), and the souped up Peko Pe natural draft gasifier presented by Paul Anderson (pictured with Crispin Pemberton-Pigott, wielding his ever present combustion analyzer). The venerable Dr. Larry Winiarski and Dean Still are also shown here with the upcoming finned pot atop StoveTec’s (www.stovetec.net) rocket stove - now 36,000 strong in the field just since last year. The trend toward stove models like all these, designed for mass manufacturing, continues, and this trend was recently discussed here: coming-of-corporate-biomass-stoves-mass.html). And yours truly demonstrated in light snow the new biomass gasifier (the red one) from All Power Labs here in Berkeley (www.allpowerlabs.org). Look soon for Peter Scott’s new rocket stove design and application website at rocketstove.org.

Resources for the interested include past conference proceedings () and reviews
(http://improvedstoves.blogspot.com/2007/02/ethos-2007-conference-report-and.html
http://improvedstoves.blogspot.com/2008/02/ethos-2008-conference.html) and the master site for all things related to biomass stoves is here: www.bioenergylists.org.

Notes from the ETHOS Conference of 2009,
by Paul S. Anderson, 4 February 2009

I enjoyed (and benefited from) the 2009 ETHOS Conference more than in most previous years.  ETHOS is growing and evolving, and so are our stoves.  

This year we seemed to have had more discussions of issues than in the past.  There were topical “panels” of usually three or four qualified people.  The topics of these plenary sessions were:  Carbon Credits; Stove Testing Issues (not results of specific stoves); Safety; and Stove Standards.  Those sessions still tended to be presentations, but there was somewhat more interaction and some effort to get to the underlying difficulties that need more discussion.  Attendees still need to read-between-the-lines and/or have some more private discussions to see some of the differences of position.  

The session Crispin and I led about controversial issues that need to be discussed was only moderately successful (in my opinion) because we spent our time identifying the issues and did not have time for discussions of those issues. Next year, we hope to have some of those topics PRE-identified and to have discussion time about those issues. I have volunteered to work on that, and Mark B. has accepted my offer. (More about this in some future messages.)

There were still about 30 somewhat standard (academic style) presentations, usually with PowerPoint slides. But they were in three concurrent sessions with 30 minutes (too much in my opinion) allocated to each presenter (who usually did make sure to fill all of the minutes, often with background info that could have been omitted, in my opinion). So each attendee could only hear about 10 of them. I will comment on four of the nine that I was able to attend. There were certainly other excellent presentations, but I am not trying to summarize the entire conference.

1. Alan Berick did a masterful job of calling attention to simmering by the use of only charcoal, available from the fire that was used to bring the pot to boil. There were questions about the heat retained in a ceramic stove body, etc., and certainly he will do more work on this. But really he called attention to the need to have “different” heat sources for boiling and simmering. This is akin to the advocacy of retained heat cookers (RHC or “hayboxes”) for integrated cooking. We should all think more about having two or more modes or devices for different cooking (as in bringing-to-boiling vs. simmering vs. tea-for-two in the morning).

2. Jonathan Cedar and Alex Drummond discussed (and later showed) their “BioLight” cookstove that includes an attractive device attached to the side of the stove to use the heat of the fire to create the electricity (via a TEG = thermoelectric generator) to drive the blower to make the fire burn well. The theory and practice have been known for a long time, but they impressively accomplished it in their attractive prototype, a variation of a Reed-style Woodgas Campstove. Neither the stove body nor the TEG power units are available for purchase, but they should be encouraged to continue their work. [Side note: The TEG in the bottom of the innovative Philips cookstove (seen in previous years) has been removed and that stove is moving to the marketplace with battery or plug-in for the required electric power.]

3. I liked my own presentation about the low emissions of TLUD gasifiers, especially if the charcoal is NOT burned in the TLUD. This favorably relates both to Alan Berick’s findings (above) and to the carbon credit and biochar sequestration topics. (Enough said. My paper is at the Stoves Internet site: http://www.bioenergylists.org/andersontludcopm I think that in future years we should have many papers placed there in advance of the conference.)

4. Nathaniel “Nat” Mulcahy attended ETHOS for the first time and (in my opinion) presented the most dramatic stove innovation I have seen since the day I met Tom Reed and his TLUD prototype. Nat presented about the Lucia Stove (and some info about the larger WorldStove). True science and engineering in action. His website is underdeveloped, but he has 13 YouTube items that will partially bring you up to speed. Visit: www.youtube.com/worldstove I will be writing more in another message about his “coaxial gasification” (vs. stratified gasification in TLUDs and most other small gasifiers). I spent some extra time with Nat and can say that he has deep understanding of the issues, and he has solutions already in place.

The “Lighting of the Stoves” was Sunday afternoon, with a light snowfall!! Five stoves were fired up.

1. The Rocket stove produced in China. Reliable, economical, and this one had a very nice pot-skirt that attached to the pot and let the emissions/draft out through (20 mm??) holes near the top of the skirt. Many people (including me) purchased one of those stoves (and would like to get the skirt). Contact Aprovecho to get your stove (under US$30, plus shipping).

2. The “PP-Plus” natural draft TLUD from Servals in Chennai, India. It uses the natural draft techniques combined by Paul Anderson and Paal Wendelbo. I will be posting within a few days a document on how to make a PP-Plus gasifier. (Wendelbo’s extremely interesting life as a TLUD pioneer was highlighted at the Friday night slide-show and is at the Stoves Website: http://www.bioenergylists.org/wendelbopekope ).

3. The GEK downdraft gasifier. This is not a cookstove. It is a gasifier intended as a start-up kit for aspiring gasifier enthusiasts, including cleaning and cooling of the gases. This is for sale as a kit or as a set of plans for construction. About forty units are around the world.

4. The Lucia Stove by Nat Mulcahy. Mentioned previously. The live-fire demo was impressive. The turbulence of the gases/flame and the air control provided a very clean combustion, measured by Crispin and his furnace-emissions analyzer.

5. The BioLight by Drummond and Cedar. Discussed previously. It performed very well, and was measured by Crispin to have very clean combustion slightly better than the other four stoves shown this year.

As someone mentioned, in previous years usually only one gasifier was among the stoves ignited. But this year four of the five were gasifiers, each distinctly different from the others.

The “Crispin Awards” were inaugurated this year. Crispin gave out three little bottles of “Gold Medal” Canadian pure maple syrup to stoves 3, 4, and 5 in the above list. The criteria were the emissions readings from his furnace emissions analysis equipment. The three winners did share one thing in common. All three were with force air, and even used true blowers, not just small fans.

In summary, it was a beneficial conference. Another report on the meeting has been posted by Kelpie Wilson, with insights especially for the issues of biochar:
http://www.biochar-international.org/projectsandprograms/memberprojects....

Hello stoves community,

At ETHOS 2009 we held a panel on stove safety, bringing in viewpoints from corporate standards development, national standards certification, and small to medium scale developers. The team led by Nathan Johnson (Iowa State University) included Crispin Pemberton-Pigott (New Dawn Engineering), Casper Thijssen (Philips), and Karabi Dutta.

The panel gave a comparative analysis of how different stove industries (multinational corporations, medium-scale companies, NGOs, small developers, etc.) addressed fundamental stove safety questions. These topics included:

a) applicability of standards and regulation;
b) incentives and benefits
c) facilities and equipment availability
d) cost vs. benefit
e) resulting action

We determined that each type of industry has a different perspective that influences their path or actions towards a safer stove. And that all sub-industries may not produce safer stoves given the same incentive mechanisms or policies. As such more than one path to safety may be needed to reach the greatest amount of end-users (and producers). The panel ended the discussion with an overview present work in stove safety with recommendations for next steps.

Please view the attached file for more details. I will be leading a group in 2009 to work on the following: assemble database of injury data, b) analyze incentive mechanisms, cost/ benefit, c) development of lab testing procedures for different stove categories, d) publication of findings/ results, and e) look for partnerships with international agencies to support safer stove design and production.

Please contact me if you have any questions. There will be more updates to follow. Best,
Nathan Johnson
atlas@iastate.edu
PhD Candidate, Mechanical Engineering, International Development
Iowa State University

ETHOS 2009 PROGRAM
Mark Bryden, January 21, 2009
ETHOS 2009 – Changing the World… one household at a time
NGOs, academics, students, technical trainers, and global programs.