From pverhaart at optusnet.com.au Sun Jul 1 06:23:21 2001 From: pverhaart at optusnet.com.au (Peter Verhaart) Date: Tue Aug 31 21:36:57 2004 Subject: FORUM In-Reply-To: <008f01c0ffee$4a5bbf80$ee85a141@tedscomputer> Message-ID: <5.1.0.14.2.20010630213457.00a73ec0@mail.optusnet.com.au> Tom Miles, Ron Larcon, Alex English and Tom Reed. I would like to express my great appreciation for the way you have and are running the Stoves List. I am sure a great many like myself enjoy the results of your efforts. Piet - Stoves List Archives and Website: http://www.crest.org/discussion/stoves/current/ http://www.ikweb.com/enuff/public_html/Stoves.html Stoves List Moderators: Ron Larson, ronallarson@qwest.net Alex English, english@adan.kingston.net Sponsor the Stoves List: http://www.crest.org/discuss3.html - Other Biomass Stoves Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml For information about CHAMBERS STOVES http://www.ikweb.com/enuff/public_html/Chamber.htm From ronallarson at qwest.net Sun Jul 1 09:36:09 2001 From: ronallarson at qwest.net (Ron Larson) Date: Tue Aug 31 21:36:57 2004 Subject: Fw: Briquettes with holes (2) Message-ID: <007a01c10232$a225ef60$e6f4b4d1@computer> Stovers:        Several comments on the following Friday message from Tom Duke:   1.  I heard Mark Hertsgaard talk on his book at the year 2000 ASES meeting at Madison.  I strongly recommend the book - which I also bought (autographed).  Mark describes travels around the world talking to both powerful and ordinary people - only about the environment.  I believe he found China to have the worst environment of any place he went. I also have heard the Chinese are cleaning things up pretty rapidly.    2.  As near as I can tell, we have no one on the "stoves" list from China.  But Ralph Overend and Helena Chum from NREL have been there.  Maybe they or others who have been to China on stoves expeditions can give their thoughts on the good and bad aspects of these coal "honeycombs".  Anyone able to report on all the important dimensions and numbers of holes?   Should there be a difference between the appropriae "holiness" of briquettes using biomass vs. coal?    3.  I first "met" Tom Duke via e-mail as the first person to try the charcoal-making stoves idea back in 1995 (?), after I wrote in to "bioenergy".    Tom reported within days on two really brilliant additions -       a ) half (?) filling a really tall (4 meters?) chimney pipe (30 cm diameter?) with "sticks" and top lighting as a barn overnight heater. With top lighting he got the usual 25% (?) charcoal production and a very long continuous Power output.   (Tom - can you tell when and where that might be archived?)       b)  Building the charcoal-making stove entirely as two side-by-side holes in the ground (zero capital expense).  Again got good (?) charcoal production, controllable output, low emissions.  (Tom - again can you tell when and where that might be archived?  I know both preceded the start-up of "stoves")   4.  On my way to Madison a year ago, I stopped in to see Tom and family for a few hours of real talk (and lunch).  We don't hear enough from Tom on stoves because his passion is wind generation.  Small test wind generators of novel design were all over Tom's pretty large (and lovely) farm and barn.  I strongly recommend Tom to anyone listening in who is looking for a really bright widely-read farmer/engineer/scientist to try out new ideas.  (I am talking about for pay usually - so far his inputs have all been for free.)  Tom is a lot like Alex English (a tad older) for those of you who know Alex.   Tom - thanks for the valuable addition.   Ron     ----- Original Message ----- From: Thomas Duke To: Ron Larson Sent: Friday, June 29, 2001 8:52 AM Subject: Re: Briquettes with holes (2) Ron:Page 163 of "Earth Odyssey" by Mark Hertsgaard has this: " I was especially intrigued by bikes carrying the coal briquettes locals called "honeycombs" (because of the holes drilled in the briquettes to encourage cleaner burning). Round, black, the size of small coffee cakes, the honeycombs were stacked by the hundreds into squat pyramids and sold off the carts for burning in the home stoves of the poor. Honeycombs were said to be the cause of much of China's air pollution, but where was the pollution?" Mark in in Beijing when he is seeing the squat pyramids of honeycombs. Tom Duke (Tom 1 day earlier wrote this - but I don't think either went to all stovers:   Ron and stovers:The Chinese use a coal they call honeycomb coal. It has holes drilled in it. I don't have pictures. But I read about it in one of the books; I think it was "Earth Odyssey" by Mark Hertsgaard, 1998, Broadway Books, New York. ISBN 0-7679-0058-8He said it was preferred because of the quality of the burn.)  Ron Larson wrote: Stovers:   The following is a relatively "new" topic that I hope others can comment on - especially those who have similar photographic or other data.       From ronallarson at qwest.net Sun Jul 1 16:49:22 2001 From: ronallarson at qwest.net (Ron Larson) Date: Tue Aug 31 21:36:57 2004 Subject: briquettes with holes In-Reply-To: <3B3D7708.00000B.15435@pentium-333> Message-ID: <00fe01c1026f$17dbf100$e6f4b4d1@computer> Elsen (cc: Stovers)       1.  Thanks for the quick input on this issue.    See more notes below.  
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From: elk To: stoves@crest.org Sent: Saturday, June 30, 2001 12:51 AM Subject: briquettes with holes >Our experience here in Nairobi indicates that the larger the briquette the less breakage there is in transport and the lower the amount of waste fines.   (RWL--1) I am sure you are correct that the extra edges can create new potential breakage problems.  But I wonder about these solutions:       a.  Maybe there could be some "rounding" - more like a donut"  (both inner and outer "edges" - a term that doesn't apply well to a donut).     b.  Maybe there is some reduced body tensions due to better drying characteristics (which might be the reason Richard Stanley has used the interior hole).   >This is a simply due to the fact that there fewer 'edges' per kilo with larger briquettes- the edge of a briquette being the area most susceptible to breakage.   (RWL-2):  This would seem to have some upper limit.  Can you describe this more in terms of thickness as well as diameter.  What are your optimum dimensions now?  Could you try holes in the way you are making your briquettes?   >Briquettes with holes have almost double the 'edge distance' that solid briquettes have, are much more prone to being crushed and would certainly burn faster due to higher surface area.       (RWL-3): I know that you use a lot of clay to prolong the burn - and your customers like this feature.  Is it possible that Richard's use of "raw" biomass would lead to a different optimization to your concentration on starting with charcoal fines?   Might it be possible that intense burns but with a smaller input (number of briquettes) but with higher overall efficiency would be a better way to go?  This has been the approach of Paul Hait with his "thermal array" of charcoal briquettes.     >I would expect that only an unusually large briquette, stood vertically in a stove with good ventilation and carefully lit from below would exhibit any form of chimney effect.       (RWL-4):  This is a great question, that I hope you and others can look into.  Clearly, a few centimeters of heighth isn't going to create a huge draft.  On the other hand there is still some theoretically, and the interior of the hole is creating plentiful gases, which in turn has to create a large velocity to maintain a steady state.  The photographs show such vigorous combustion clearly.     (RWL-5)  I would like to see a test with the hole's axis lying horizontally.  I think there may still be sufficient (internal-to-the-hole and circular symmetry) radiative heat transfer to drive a significant flame even in that position.  Anyone have any results to report?  (Photographs?)  This is the geometry closest to what Paul Hait does.     (RWL-6):  Some of us at the Pune conference will remember a talk by John Rouse - in which he described a grate made of homemade ceramic "rods".  I am thinking of the "donuts" resting in a "non-flat" position between these grate rods.   >On the positive side, the lower bulk density and novel form of a briquette with a hole could be marketing advantages.   (RWL-7):  I'm not sure why that should be the case, but will take your word for it.  The description by Tom Duke of carrying them suggest that it might be possible to carry them easily when tied up with a single thong.  I hope Richard can comment on the marketability aspects.   (RWL-8)  Others on the list (such as Richard Stanley) may not have been on the list long enough to know of Elsen's considerable background in doing briquette-related research (as well as charcoal-making and charcoal-making stove research as well).   Elsen has a major business starting up in Nairobi in the making and marketing of chrcoal briquettes.  Some of this has been with bagasse and sugar cane residue.  Elsen - from what you know of Richard's approach, do you think that making the briquettes from sugar cane residue would be feasible - and marketable?  The part I like about this approach is that one doesn't lose two-thirds of the energy in the initial pyrolysis.  If Richard's combustion process is complete enough, perhaps biomass briquettes can be provided cheaper than charcoal.  What do you think?   (RWL-9)  Thanks for your input.  I think we will probably be discusing this for a bit longer.  Yours can be a major factor in better undestanding this interior hole phenomenon.   Ron     >elk     Elsen Karstad elk@wananchi.com www.chardust.com _________________________________________________IncrediMail - Email has finally evolved - Click -------------- next part -------------- A non-text attachment was scrubbed... Name: bin00222.bin Type: application/octet-stream Size: 1431 bytes Desc: " Here" Url : http://listserv.repp.org/pipermail/stoves/attachments/20010701/89cd0971/bin00222.bin From ronallarson at qwest.net Sun Jul 1 22:09:00 2001 From: ronallarson at qwest.net (Ron Larson) Date: Tue Aug 31 21:36:57 2004 Subject: Fw: Briquettes with holes Message-ID: <000301c1029b$b47f1ba0$5c7de13f@computer> A.D. (and Stovers):       Your comments, as usual, are very interesting. Thanks   Before some questions, let me tell new stoves members that you led last November's stove conference and head a major successful Indian development group that has done some very fine stove work.  In the following, I should also mention that you and I have both been members of a bamboo list - but your knowledge is enormously better than anyone I know on bamboo (and a whole range of biological topics).       More below.     ----- Original Message ----- From: A.D. Karve To: Ron Larson Sent: Friday, June 29, 2001 7:53 AM Subject: Re: Briquettes with holes Dear Ron, >In one of the publications by Dr. P.D.Grover of New Delhi, India, I saw a fat cylindrical char briquette. This briquette fits snugly into the hollow space of the stove, so that you use just a single briquette at a time. The briquette has 19 vertical holes, symmetrically arranged, equidistant from each other .  You ignite it from below, and once all the cylindrical cavities are burning, you get a uniform hot front hitting the pot kept on the stove. Dr. Grover calls it a honeycomb briquette.  We made such briquettes and tried them out. They had many disadvantages. The very first one was the difficulty in getting all the holes burning simultaneously.       (RWL):  I know of several other Grover technologies but was not aware of this one.  Many of his stove designs have been for charcoal making - and I wonder if this was also.  I believe it might well be a successful charcoal making design if lit from the top.   I can't be sure, but I believe that you will then find all holes burning simultaneously.  In all the charcoal-making stove tests I have perfomed, such was the case.  Stopping a burn (by smothering or using water) has mostly shown a horizontal flat demarcation between the charcoal and unpyrolyzed regions. I can't give a good reason for why this should be so - but believe the Grover 19-hole unit will "draw" evenly.  But it must be lit on the top.     >Another was that this briquette did not leave you any freedom to control the heat. In a normal charcoal stove, you can control the heat by adjusting the number of charcoal lumps burning in the stove.  This flexibility was not available when you used the honeycomb briquette. Initially it produced less heat, then it produced very intense heat, as as the briquette burnt itself out, the heat ebbed. If you still needed intense heat, there was nothing you could do.   (RWL):  One of the beauties of a charcoal-making stove is that one does have good control over power output  - by controlling the primary air.  We have been getting a ratio of about 3:1 for Pmax/Pmin.  But again, one has to use top lighting.  Once the primary air has been established, the power output stays quite constant.     I am less sure that all this will work with a solid piece with 19 holes.  As you have indicated below, it may be better to place 19 straight pieces into a cylinder in which they fit tightly (leaving "triangular" spaces between).  One may need some lateral "communication" between the air passageways - which is not possible with the 19-hole design.  But this is a needed experiment.  If you have any of these 19-hole briquettes left (or can make them still easily), I hope you will try (with top lighting).     >In a charcoal stove or in one using smaller char briquettes, you go on adding a few fresh charcoal lumps or briquettes, to give a constant high heat intensity over any length of time. However, after we had completed our studies, somebody told me that the honeycomb briquette was not meant for a cookstove but for a stove used for room heating! Fortunately, we don't need any room heating in Pune.       (RWL):    Could you give us some more background on the dimensions of the "Grover" briquette and holes - and the difficulty of making them.   >In our conference in Pune, last November, there was a paper from Asian Institute of Technology, Bangkok, describing the production procedure of a hollow cylindrical briquette.  The hollow cavity would certainly give intense heat, as suggested by you, but in order to use that heat effectively for cooking, all the briquettes must be vertically oriented. In fact, even our solid cylindrical char briquettes produce the same effect if the cylindrical briquettes are arranged vertically, packed in such a way within the firebox of the stove, that they touch each other. The triangular empty spaces left between the adjacent briquettes have the same effect as that described by you for a hollow cylindrical briquette.  Yours Nandu     (RWL):  I have now forgotten the details of that AIT paper.  Could you (or they) remind me of what the results were? (Dimensions?  biomass or charcoal?) As I said in a message immediately preceding to Elsen Karstad, I am not so sure that the stacking must be vertical.  I believe the radiative effect will be stronger than the convective effects. I presume that you have not used your packed cylinder approach with top-lighting?      I am glad that you wrote especially because I wanted to talk about using short sections of bamboo as "one-hole-briquettes".  As bamboo (any other plantss?) comes in dozens of species and (I believe) have central holes of many sizes, it would seem that we should be learning more about its combustion characteristics when used in short sections.  My only perception of burning bamboo is in long sections. Could you (and anyone listening with access to dry bamboo) try some experiments with different length to diameter ratios and oriented in the stove in different ways (bamboo central axis pointed both up and horizontally).  I am guessing that the combustion properties witll be improved with short hollow sections.  This should be an "easy" way also to test the flame properties with diferent orientations and separations.  If really better by exploiting the advantages (if any) of this different form of encouraging combustion, perhaps there could be a bigger role for bamboo in household cooking - which I know is of interest to you..   Thanks in advance for any new data you can add.   Ron
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From: Ron Larson To: stoves@crest.org ; "Richard Stanley" Sent: Friday, June 29, 2001 11:03 AM Subject: Briquettes with holes         From ronallarson at qwest.net Sun Jul 1 23:11:55 2001 From: ronallarson at qwest.net (Ron Larson) Date: Tue Aug 31 21:36:57 2004 Subject: Briquettes with holes - (R. Stanley) In-Reply-To: <4.3.1.2.20010629093006.00e15930@mail.ilstu.edu> Message-ID: <00db01c102a4$6e068e20$5c7de13f@computer> Richard and all stovers: Thanks for the answers below - I will just ask a few more questions below: > > Holes: The hole has effect only when the radius of the briquette is about > equal to its height. > I have played with surface area to volume ratios but this simple rule of thumb > works quite well. The diameter of the hole is optimal at 1/4 to 1/3 the > diameter of the briquette. > > > As to Tom Larson's concern for pyrolsis migration rates, our study, published > in the American Chemical society's Journal of Chemical Innovation this past > February, identifies two distinct kinds fo heat being generated in the burn > cycle. (RWL): I tried unsuccessfully to reach this site. More after I read the article. >The first is a rapid rise to 800 centigrade within about 6 to 10 > minutes for five to fifteen minutes, with licking convective flames. The > flames then die down to yeild an infrared glow in the core for the remaining > 20 to 30 minutes. The briquettes even if exposed to an evenly applied heat > source all around their bottom, will tend to burn from the center out, not > uniformly and not from the outside in. > > Carbonisation begins in teh center and ends on the exterior surfaces. > (RWL): I don't understand "carbonization" - which I would reserve for processes that leave carbon (charcoal) at the end of the cooking (which is the case for our charcoal-making stove). I presume that there is total combustion? Do you use this term to imply that there is a pyrolysis process going on throughout? Can one get a more continuous power by placing the briquettes on the fire in a staggered fashion? Are cooks happy with the time sequencing of the power output? > Application of such as Approvecho's Justy or Rocket stove would retain heat > in the combustion chamber and allow for retention long enough to complete > combustion. we have created similar chambers with 1 inch annular spaces . The > effect was to create an induced draft outside the briquette which tended to > augment secondary combustion above the briquette but the burn was still most > intense through the center core. This is only part of the story however. > What needs to be added to either of these stoves or anyone elses for that > matter, would be a direct feed of air from beneath the briquette and a grate > to let the resulting ashes (and there is s considerable production of ash, > relative to charcoal or wood) fall off , retaining open exposure of the > glowing red core to the cooking surface. The attached burning demonstration up > in the Andees a few weeks ago gives you the idea. Also attached is a suggested > modification of stoves to utilise the briquette in teat same region. > (RWL): I am suffering from still not undertanding the full operation of your stove (so I apologize for not having read the above article). I now gather that the intense flames do not continue throughout the burn. Better let me read more. Is it possible to "jiggle" the briquettes to remove the built-up ash? and restart the moe intense power output? > Blocking the hole reduced the heat output of the briquette to nothing much > more than a pile of compressed leaves or if you use it sawdust or carbon dust > or whatever you use are a resource. It is nothing like the center core burn > effect, everything else being equal. > (RWL): Could you clarify "blocking the hole"? How is this accomplished? > It is our and teh technology's godafather, (Ben Bryant's) original and > continuing intent to produce a technology so readily do-able that in the right > location of demand and entrepreneurial capacity, it immediately "ignites" > interest and generates direct income amongst the poorest of the poor. > (RWL): Can you give any references on the work of Bryant? > The basic starter press I detailed to Paul can be paid back in a few weeks of > production. In some areas we encourage the trainers NOT to sell it for cash > but rather set in motion the idea of producing briquettes to pay for the > press. paybeck times are under these circumstances around 6 weeks. > And as the entrepreneur expands and needs higher [produciton capacity, we can > step over to a reciprocating ram, even making it double-acting, with a feed > and sump tank but we have always to think carefully about who will afford it > and how will it be maintained. But I do not mean to imply that we are not > holding back where the demand and capacity exists: In fact newer and far more > productive presses are emerging out of necessity in places like Cusco Peru and > probably in Kangemi Kenya and in the northern province of Haiti later this > year. (RWL): I have zero background in briquette presses. It sounds like you are doing very well on this side. I am impressed by what you have done. > > Further into the technology still, we are considering a more sophisticated > application for the US household and municipality, ever more laden, as they > appear to be, with junk mail and yard waste but that takes money and a serious > investment group (if anyone is interested !) > (RWL): I hope others with briquetting background and support will be contacting you. > A group in Cusco at their San Antonio University, is eager to design the > perfect briquette. The problem is that it is not an issue of greater pressure > (the process of wet slurry dewatering is quite elastic with respect to phase > change. We operate ao 10 to 15 atmospheres. there is nor substantial change in > the density or burning quality at four times this much pressure --although the > capital and operating cost of the required equipment would indeed rise > sharply. > (RWL): Please help me with the term "phase change". From what initial phase to what final phase? > Nor is the quality of the burn defined by an exact ratio of the natural > resources we use, for these change in compostiion substantially according to > teh time they are harvested and teh point at which they are pulled out of the > decomposition cycle--- which is an essential step in preparing the material. > However, the method and principles used in determining the right compostiion > is exact. It is exact but extremely dependent upon the feel for the material. > Sure, the more carbonaceous the material, the greater calorific value, but if > the briquette is spongey or for that matter too tight, it will be less > efficient than well prepared mixtures of your died out garden variety grass > clippings leaves. > > Thus far its been all about developing this capacity in the third world. It is > here where that kind of "feel" for agro residue material comes quite > naturally. It is another story to try to train colleagues back home. That is > why I sometime cringe at the notion of someone simply grabbing a press and > running off to train someone else without proper training themselves. Quite > frankly they would do better to go to Particia Ngari, or Nestor Velasquez, or > Seif Salmini, for their own knowledge of their own area, than myself. > (RWL): I hope they will all feel free to jump in with guidance for the rest of us. > Think I will have to lug one of these presses to the Biomass conference this > September. If we accomplish nothing else, we can all make and take home our > winter heating supply out of the left over papers... > > Happy 4th to you all > > Richard Stanley > Legacy foundation > 541 488 1559 > > > (RWL) Richard - Thanks again for your responses above. I won't go over my questions, since there are probably answers in your written technical paper. If not I'll be back. I wish I had gotten my inquiry started a little earlier so as to ask a few questions also of Paul Anderson (now presumably in the air on his way to SA). Later. I hope he will keep us abreast of what he is doing if he can get to a terminal. I have made a number of other responses and questions in my three responses to Tom Duke, Elsen Karstad, and Dr. Karve. Please jump in if anything I said has been in error. Again congratulations on some very interesting briquette and stove work. Sorry for not jumping in earlier. Ron - Stoves List Archives and Website: http://www.crest.org/discussion/stoves/current/ http://www.ikweb.com/enuff/public_html/Stoves.html Stoves List Moderators: Ron Larson, ronallarson@qwest.net Alex English, english@adan.kingston.net Sponsor the Stoves List: http://www.crest.org/discuss3.html - Other Biomass Stoves Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml For information about CHAMBERS STOVES http://www.ikweb.com/enuff/public_html/Chamber.htm From elk at wananchi.com Mon Jul 2 01:41:53 2001 From: elk at wananchi.com (elk) Date: Tue Aug 31 21:36:57 2004 Subject: Where There's Fire...... Message-ID: <3B4008DB.00001D.14313@pentium-333> Stovers;   Some background from Kenya......     Where There’s Smoke There’s Charcoal……….   Next time you order your kilo of roast meat at the market, give a thought to the fact that you about to consume half a kilo of charcoal at the same time- or five kilos of wood from the tree’s point of view……..    Some figures here- they get interesting:   Of Kenya’s 28 million inhabitants, 20% are urban dwellers. Sixty percent of these 5.6 million urbanites use charcoal as their domestic fuel of choice on a daily basis- more than 500 grams per person per day. Taken at conservative rate of consumption, this amounts to One Million, Six Hundred and Eighty Thousand kilograms of charcoal consumed in Kenya’s cities PER DAY.   Hold on- if we take the tree’s point of view again, how much actual wood is this? Well, the earthen-mound kiln technique of carbonization is about the most inefficient method available, and effectively the ONLY method currently in use in Kenya. You get a charcoal yield from wood of between 8 and 13%- say 11% on average. This means that on every day of the year some Fifteen Million Two Hundred and Seventy Three Thousand kilos of tree are cut down and burned into charcoal.   If your average charcoal-fodder type tree weights, say 50 kg, this amounts to one hundred and Eleven Million Four Hundred and Ninety One trees in a year. At one thousand trees per hectare, this amounts to eleven thousand square kilometers per year……..   Kiln efficiency can be increased to close to 40% with tight controls. In commercial practice just under 30% is achievable with the use of metal or brick kilns. Sawdust can be converted to charcoal powder at a 36% yield via the downdraft system.     The problem here is that there is no incentive to increase efficiency- the wood is free for the taking. If wood was sourced from commercially planted and nurtured woodlots it would have a commercial value prior to carbonization- conversion efficiency would then be important. As-is, with uncontrolled access to free material, the overriding incentive is labour, and the earthen-mound is the simplest, easiest and most maintenance-free method. Until the perceived value of wood as the raw material for the manufacture of charcoal changes, there’s little hope in controlling the impact of the charcoal industry on Kenya’s increasingly disturbed woodlands and forests.       Elsen Karstad Chardust Ltd. www.chardust.com   _________________________________________________IncrediMail - Email has finally evolved - Click Here From elk at wananchi.com Mon Jul 2 14:08:41 2001 From: elk at wananchi.com (elk) Date: Tue Aug 31 21:36:57 2004 Subject: Briquettes with holes Message-ID: <3B409D14.000005.15933@pentium-333> Ron (and Stovers);   As I'm only concerned with charcoal briquettes and am using extruders exclusively, I can adress only a limited aspect of the 'briquettes with holes' discussion. I think that the larger biomass briquettes do indeed have a real need for holes- particularly those that are not compressed/extruded under the huge pressure sufficient to melt lignin and bind as dense (or denser) than wood.   To agglomerate a few of your questions here Ron- I could indeed produce extruded briquettes with holes, but I think that the number of rejects would rise tremendously. My extruders tend to warm up and mix/agitate the charcoal powder/clay/water mixture..... which (please excuse the description) exits the 6 inch long by 1.25 inch dia. extrusion die with much the same consistency and temperature as dog poo. Like dog poo, the briquettes firm up as they cool. Unlike dog poo tough, they don't attract flies when laid out on the drying racks (thank goodness).   Anyway- the point being, is that low pressure extruded briquettes with holes would tend to collapse upon extrusion unless drawn out of the machine on a conveyer. I'm sure that by increasing the pressure (using more power) and feeding a drier mixture, some extruders would indeed happily produce hollow briquettes.   More intense burns- and I'm sure that vertically arrayed briquettes like Paul Hait's brilliant Pyromid inspiration are great when controlled. The problem arises with duration. I simply do not like having to continuously feed a charcoal fire. None of my customers want to either. The commercial trade-off between intensity and duration tends to favour duration when it comes to charcoal customers here in Africa. Slow is better, as long as the minimum acceptable amount of heat is produced for the job at hand. This would tend to be a negative factor against hollow charcoal briquettes.   And efficiency? Well, that depends very much on the properties of the stove, and in my experience you can cook more food on slow-burning fuels.   As for the commercial aspects- most charcoal here in Kenya is sold by volume. A four litre paint tin, a 20 litre vegetable tin and a feed sack are the three most common measures. It would certainly help me to have a hollow product- air is cheap! The novelty value of marketing a hollow briquette could amount to a brand or trademark, and with it the opportunity for a value-added profit. I'm not there yet though- still struggling to compete on a price-basis with lump-charcoal made from illegally harvested wood. Hmmm.... maybe it IS time to look for profits though......   elk   Nairobi www.chardust.com _________________________________________________IncrediMail - Email has finally evolved - Click Here From english at adan.kingston.net Mon Jul 2 18:17:48 2001 From: english at adan.kingston.net (*.English) Date: Tue Aug 31 21:36:57 2004 Subject: Webpage update Message-ID: <200107022215.SAA17910@adan.kingston.net> Stovers, You can view some new pictures, related to briquettes with holes, from Richard Stanley. Check the "New" section. Alex - Stoves List Archives and Website: http://www.crest.org/discussion/stoves/current/ http://www.ikweb.com/enuff/public_html/Stoves.html Stoves List Moderators: Ron Larson, ronallarson@qwest.net Alex English, english@adan.kingston.net Sponsor the Stoves List: http://www.crest.org/discuss3.html - Other Biomass Stoves Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml For information about CHAMBERS STOVES http://www.ikweb.com/enuff/public_html/Chamber.htm From reap at interlink.net Mon Jul 2 20:38:34 2001 From: reap at interlink.net (REAP-Canada) Date: Tue Aug 31 21:36:57 2004 Subject: The energetics of corn burning In-Reply-To: <20010629035652.17021.qmail@web13507.mail.yahoo.com> Message-ID: <001901c10358$3b935040$0201010a@proview> Norbert wrote: > One item that should be added to the discussion is energy quality. Methanol > can be used to power cars, whereas pellets can't (very easily, anyway). > > Space heating requires low grade heat, so burning ethanol for space heating > doesn't make any sense. Neither does electricity or oil or gas, for that > matter. ("Cutting butter with a chainsaw", as Amory Lovins said). (snip) I couldn't agree with Norbert more about the need for the energy quality discussion. It just hasn't happened in a significant way.We had some discussion on energy quality here previously late last year (see the thread "widening the discussion about bioenergy development"). Perhaps it would be good if we could bring in some energy analysts like Amory Lovins and David Pimental as speakers at a biomass conference to provoke discussion. My feelings are that the excessive transformation of the energy quality of biomass ... "the straw to gold" approach is the technologists dream but it ends up being the energy analysts nightmare..and the economics follow. Turning biomass into a fully modern energy carrier like electricity or liquid fuel limits its potential for economic success in the near term in most regions of the world. As a naive and enthusiastic student of biomass energy 10 years ago, I invested my retirement savings in a methanol company that is now a penny stock...today I invest in railstocks and they are doing pretty well....there isn't enough land in the world to do it all with biomass and fossil fuels will long hold onto the transportation market. Biomass can however make major inroads in the energy sector by using pellets (an energy carrier of intermediate quality) to displace high grade energy forms (like oil, natural gas and electricity) in heat related energy applications. For example in some hydro rich provinces in Canada up to 60% of the houses are heated electrically. Indirectly, biomass could make major contributions to the grid by displacing electrical heat in these applications. So there is no need to focus on direct biomass power production when we can "produce" about 2.5 times as much electricity indirectly from the same hectare of biomass if it is used for space heating to displace electrical space and hot water heating. So to paraphrase Lovins, we indeed need to match the energy quality of the fuel with the end use application. However, there needs to be convenience for most people, and the fully automated fuel supply systems that are being developed for pellet stoves and furnaces is getting close to oil and natural gas systems for user convenience. Roger Samson Resource Efficient Agricultural Production (REAP)-Canada Box 125 Maison Glenaladale Ste Anne de Bellevue, Quebec, H9X 3V9 Tel. (514) 398-7743, Fax (514) 398-7972 REAP@interlink.net WWW.REAP.CA "Creating ecological systems of energy, fibre and food production" ----- Original Message ----- From: Norbert Senf To: ; Sent: Friday, June 29, 2001 10:44 AM Subject: Re: The energetics of corn burning > At 10:03 AM 2001-06-29 -0400, REAP-Canada wrote: > >(snip) > > > >I do not know if money is well spent continuing to prime the ethanol pump > >with subsidies (or value added grants as they have been recently called) > >when there could be major R & D efforts to develop biomass > >heat...bioenergy's best comparative advantage for development. > (snip) > > One item that should be added to the discussion is energy quality. Methanol > can be used to power cars, whereas pellets can't (very easily, anyway). > > Space heating requires low grade heat, so burning ethanol for space heating > doesn't make any sense. Neither does electricity or oil or gas, for that > matter. ("Cutting butter with a chainsaw", as Amory Lovins said). > > One fuel that is often overlooked for space heating is cordwood. Recent > advances in masonry heater combustion technology, for example, allow it to > be burned on a domestic scale with particulate emissions in the same range > as pellets, about 1 g/kg. > > Best ....... Norbert > ---------------------------------------- > Norbert Senf---------- mheat@mha-net.org-nospam > Masonry Stove Builders (remove -nospam) > RR 5, Shawville------- www.heatkit.com > Quebec J0X 2Y0-------- fax:-----819.647.6082 > ---------------------- voice:---819.647.5092 > > > > > > > - > Stoves List Archives and Website: > http://www.crest.org/discussion/stoves/current/ > http://www.ikweb.com/enuff/public_html/Stoves.html > > Stoves List Moderators: > Ron Larson, ronallarson@qwest.net > Alex English, english@adan.kingston.net > > Sponsor the Stoves List: http://www.crest.org/discuss3.html > - > Other Biomass Stoves Events and Information: > http://www.fsec.ucf.edu/bioam/ > http://solstice.crest.org/renewables/biomass-info/ > http://solstice.crest.org/renewables/biomass-info/carbon.shtml > > For information about CHAMBERS STOVES > http://www.ikweb.com/enuff/public_html/Chamber.htm > - Bioenergy List Archives: http://www.crest.org/discussion/bioenergy/current/ Bioenergy List Moderator: Tom Miles, tmiles@trmiles.com Sponsor the Bioenergy List: http://www.crest.org/discuss3.html - Other Bioenergy Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml From kdavies at igc.org Mon Jul 2 21:09:12 2001 From: kdavies at igc.org (Karl Davies) Date: Tue Aug 31 21:36:57 2004 Subject: The energetics of corn burning In-Reply-To: <20010629035652.17021.qmail@web13507.mail.yahoo.com> Message-ID: <3B411AD3.F231D257@igc.org> REAP-Canada wrote: > I couldn't agree with Norbert more about the need for the energy quality > discussion. It just hasn't happened in a significant way.We had some > discussion on energy quality > here previously late last year (see the thread "widening the discussion > about bioenergy development"). > Perhaps it would be good if we > could bring in some energy analysts like Amory Lovins and David Pimental as > speakers at a biomass conference to provoke discussion. Sorry, but I wouldn't consider Lovins much of an energy analyst. As far as I know, he still thinks we have 200 years of natural gas to burn. He also thinks his Hypecar (sic) and the "New Hydrogen Economy" will save Industrial Civilization. Fat chances. Lovins' and Hawkens' messages play well with the "progressive" corporate types they get paid so well to hang out with. But their messages just don't fit with the realities of declining hydrocarbon resources and net energy analysis. Pimentel is another story. Karl Davies http://www.daviesand.com http://groups.yahoo.com/group/energyresources/messages - Bioenergy List Archives: http://www.crest.org/discussion/bioenergy/current/ Bioenergy List Moderator: Tom Miles, tmiles@trmiles.com Sponsor the Bioenergy List: http://www.crest.org/discuss3.html - Other Bioenergy Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml From karve at wmi.co.in Mon Jul 2 22:18:13 2001 From: karve at wmi.co.in (Priyadarshini Karve) Date: Tue Aug 31 21:36:58 2004 Subject: briquettes with holes Message-ID: <000d01c10367$033b0940$112033ca@karve> Stovers,     A.D. Karve (Nandu) has already written of our experience with the char briquettes with hole(s). I just want to add a few things.     Firstly, he forgot to mention another disadvantage of the honeycomb briquette - the method of production is not favourable for mass production. The briquettes need to be made by hand, one at a time, using a mold.     Secondly, I think that our method of stacking cylindrical briquettes vertically in a regular pattern, is somewhat similar to (perhaps a primitive version of ) Paul Hait's Harmonic Thermal Array. Having seen both our stack and the HTA in action, I suppose any arrangement of the briquettes, that allows sufficient air gaps in between, should work in the same manner.       Regarding Ron's suggestion of lighting from the top: Please note that what Nandu and I are talking about here are briquettes made from 'char', so there is no question of producing charcoal while burning the briquettes.        In his first message, Ron has mentioned my work on the sawdust stove. In this stove the sawdust is manually packed around an L shaped cavity. Thus, in a way this is a rather big biomass briquette with a central hole. I found that with a proper height to diameter ratio (6:1 in my case), one gets a smokeless blue flame from the central hole. I also found that one can introduce multiple tunnels in the packed sawdust, however this is a bit tricky, as the sawdust is to be packed manually in the stove, and dense packing is important to the stove operation. I have operated the stove with three symmetrically placed L shaped tunnels (tunnel dia 4 cm), and was quite satisfied with the result. In a way, this is like a honeycomb biomass briquette, but with just three rather than ninteen holes.     We have also experimented with lighting from the top in the sawdust stove. This produces a very tall and vigourous flame, not quite suited for cooking, with the existing design of the stove (no control over the primary air). I suppose a design similar to the Turbo stove/charcoal making stove would be a natural end-point in the evolution of the sawdust stove if we experiment with lighting from the top.       Regards,     Priya     Dr. Priyadarshini KarveLecturer in Physics, Sinhgad College of Engineering, Pune, India.Member, Appropriate Rural Technology Institute, Pune, India.Founder Member, Sandarbh, Pune, India.   Address for correspondence: 6, Koyna Apartments, S.No.133, Kothrud, Pune 411 029, IndiaPhone: 91-020-5442217/5423258E-mail: karve@wmi.co.in / adkarve@pn2.vsnl.net.in  From elk at wananchi.com Tue Jul 3 01:10:04 2001 From: elk at wananchi.com (elk) Date: Tue Aug 31 21:36:58 2004 Subject: Snapshot from Nairobi: Energy costs Message-ID: <3B4152D5.000010.17395@pentium-333> Stovers;   It is said that you can double the cost of cooking at each point between the following fuels:   wood >> charcoal >> kerosene & LPG >> electricity   This point is driven home with an analysis of the comparative costs between heating water with charcoal and electricity:   I've recently started marketing a simple upright 90 litre cap'y charcoal-fired water heater here. It's pictured in the Stoves website- using five vertical 1" dia. pipes as chinmeys running through a tall cylindrical water tank. The firbox is in the base.   We've tested this out at close to 50% efficient, which is pretty good, and I understand that by comparison, immersion water heaters are running at close to 75%. Please correct me if I'm wrong here or if any of the following analysis is flawed:   In Kenya we pay as much as US $ 0.14 per kilowatt-hour for electricity. My observation is that it takes a minimum of 2 hours for a 3 kW electric immersion heater to raise 90 litres of water 50 ' C. This is effected at a cost of (.14*3)*2= US $ 0.84.   My charcoal heater does the same amount of work in roughly the same amount of time with 2.5 kg of my briquetted vendor's waste charcoal at  cost of usd $ 0.17   This does underscore why lower income groups here in Kenya aren't connected to the National grid, doesn't it? The wide disparity in energy costs here is also highlighted, and just maybe the energy from biomass is undervalued? Is this gap quite as large in developed countries too?   elk Nairobi www.chardust.com _________________________________________________IncrediMail - Email has finally evolved - Click " Url : http://listserv.repp.org/pipermail/stoves/attachments/20010702/41176881/bin00223.bin From heat-win at cwcom.net Tue Jul 3 01:58:51 2001 From: heat-win at cwcom.net (Thomas J Stubbing) Date: Tue Aug 31 21:36:58 2004 Subject: [Fwd: [energyresources] Sustainability plans] Message-ID: <3B415DBA.FA47982E@cwcom.net> Dear All, Opinions vary as to when first oil, then natural gas and fnally coal will run out but certainly we cannot go on burning four times as much oil as is being discovered for ever! In that and the broader context outlined in this forwarded message (sent to the 'gasification' but not to the 'stoves' list) we are going to need stoves as never before. I hope you find it interesting. Regards, Thomas J Stubbing To: "energyresources" Subject: [energyresources] Sustainability plans From: "Kermit Schlansker" Date: Mon, 2 Jul 2001 11:41:03 -0400 Cc: "solar conc." , "Sustainable Community" , "Gasification" , "Malletts Creek Group" , "smartgrowth" , "ROE" Delivered-To: mailing list energyresources@yahoogroups.com List-Unsubscribe: Mailing-List: list energyresources@yahoogroups.com; contact energyresources-owner@yahoogroups.com Reply-To: energyresources@yahoogroups.com          I wish all of you on ROE, and energyresources would stop bickering, stay on subject, and concentrate on work that  will help save my Grandchildren. A book which is very much on subject which I hope some of you will buy is "Renewable Energy" from Island press This book gives a good survey of solar, wind, and biomass.        As it stands now there are no tactics published on the Internet that will save society. The various energy groups are really not combining to produce a sustainability plan. I have tried but my material needs improvement and no one reads it.          We need to figure out some tactics which will make a difference. We could possibly write a manifesto and try to get some of our lawmakers to read it. Certainly it is possible to prevent wholesale death in the USA for 200 years if the right things are done.              The keys to Sustainability are apartment houses, planned communities, railroads, co manufacturing, cogeneration, everyone farming and manufacturing, no houses, no cars, no planes, technically adroit conservation, massive tree planting, solar, wind, and biomass energy and  short travel distances.             I am including my latest 4 minute speech to Ann Arbor City Council.                  Kermit Schlansker        Ann Arbor, Mi                                                       Biomass           When natural gas and oil are gone there will be insufficient coal, solar, or wind to heat houses. It will take martial law to prevent the wholesale cutting of trees. Solar and wind are regional and intermittent sources and can never replace fossil fuels in the quantity that we are using now. Possible biomass energy sources are wood, crop residues, energy crops, leaves, grasses, seaweed, algae, sewage, and manure. A mass planting of trees would not only store carbon thus slowing Global Warming, but would also make an energy source for future generations. Trees grow food in the form of fruit and nuts. Forests are useful for nature, lumber, fuel, food and topsoil. Leaves and cuttings from trees and shrubs are an excellent source of energy. Ashes from burning biomass will become a prime source of fertilizer in the future. Biomass is the only energy source that is dependable enough to heat buildings in the winter. However unless it is used in the most efficient way there will not be enough.         The most popular way of using wood to make electricity has been to convert it to steam in a boiler and then use the steam to power steam engines or turbines. Another process is to partially burn wood chips thus producing a combustible gas that can be used to run an engine. During World War 2 the Germans and many others powered cars with wood chips. I myself crouched beside the gasification stove while riding with a German salesman shortly after the war in the back of a wood powered VW bug. There is a design of a small wood gas generator on the Internet that powers a tractor. If the wood gas is ran through a catalyst it is possible to make methanol. This probably will be the prime method of making tractor fuel because it can be done anywhere in the country on a local basis and uses cellulose rather than food as feedstock.         A way of converting soft biomass to energy is to combine it with sewage in a tank and use the digesting action of bacteria to produce biogas that is a mixture of methane and carbon dioxide. The process is about 50% efficient. The really good thing about this process is that tank residues are excellent fertilizers. This gas can also be converted to methanol. In China there are many small biogas generators made from polyethylene bags. Every scrap of human and animal manure is carefully saved for these bags. Much of this energy is used for cooking.         Ethanol is a possible tractor fuel and can be made from corn or other sources of starches and sugars. This process has been controversial because food is used as feedstock and because it takes about as much energy to produce the ethanol as there is in it.          Production of Ethanol and Methanol and other biomass processes can be made more energy effective if they are done only in the winter by heating systems. In that way all of the waste heat from digestion, fermenting, distilling, chemical processes and electrical generation is used to heat the building and the process becomes 100% efficient. Another efficient way of gasifying wood and distilling ethanol would be to do it in summer using solar mirrors and collecting the waste heat to make electricity.           Local governments must get involved in planting fruit and nut trees for food and energy and do research on how to plant at lowest cost. Future generations can not exist if local governments persist in being so technically inept and morally uncaring in their attitude towards the future.                                                                           Kermit Schlansker Your message didn't show up on the list? Complaints or compliments? Drop me (Tom Robertson) a note at t1r@bellatlantic.net Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. - Stoves List Archives and Website: http://www.crest.org/discussion/stoves/current/ http://www.ikweb.com/enuff/public_html/Stoves.html Stoves List Moderators: Ron Larson, ronallarson@qwest.net Alex English, english@adan.kingston.net Sponsor the Stoves List: http://www.crest.org/discuss3.html - Other Biomass Stoves Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml For information about CHAMBERS STOVES http://www.ikweb.com/enuff/public_html/Chamber.htm From rstanley at legacyfound.org Tue Jul 3 04:16:14 2001 From: rstanley at legacyfound.org (Richard Stanley) Date: Tue Aug 31 21:36:58 2004 Subject: Briquettes with holes - (R. Stanley) In-Reply-To: <4.3.1.2.20010629093006.00e15930@mail.ilstu.edu> Message-ID: <3B417EDC.FE71D02E@legacyfound.org> > Ron et al, Following your comments to my replies about the holy briquette issue: The article is no longer posted on the web (the journal of chemical innovaiton pulls it off the site, after a few months, by policy. It was the front article in the February issue of Chemical Innovation of the ACS, titled" A Unique Approach to Conservation pp 22 - 28. Perhaps I am using the incorrect term when using the word, " carbonisation". What I am referring to is a blackening of the material from the center hole outward. If the burn is interrupted once the surface is blackened, or carbonised (smothering the briquette to prevent further combustion) the briquette will behave very much like charcoal in a subsequent burn. Indeed only in passing through this state with the licking flames etc., it begins to behave like charcoal with a radient red glowing core. There is complete combustion in that all that remains is a completely whitened, friable ash- at the end of the process but it would appear that in the process we are making a form of ?or passing through a stage of?charcoal making with incomplete combustion, in getting to that final completely combusted state. It is agreed however that this is hardly a charcoal production exercise, as the attempt is to create an oxygen rich environment, not a reducing environment. In as much as we start with partially decomposed compressed agro residues, and move through what appears to be a carbonised solid into a burning radient core before arriving at complete ash material, it is changing state. I could not honestly state whether this answers your question about a pyrolysis process going on throughout. How the cooks handle the burning rate... Most often the cooks like to simply jam them into a clay stove (see the recent Peru photos on Alex's site ) or atop a grate with little regard to alignment, other than the fact that they will try to keep them upright. The latter is usually enough to assure them of fairly good performance. The rapid rist is great for cooking quick meals . but that temperature curve will depend upon the ingredients used. In Malawi we used the water hyacinth and or the coarse (starchy residues from corn milling to slow down and extend the burn, much as clay is used in the charcoal briquettes (aside from its other advantage as a binder ). One can jiggle the briquettes or simply add more to maintina a more constant heat output but the tendency is to design the briquette burn characteristic into the mixture. You buy the mixture you want for your cooking and heating needs. Like pine versus Oak or hickory smoked versus mesquite flavored. its hyacinth vesus mango or cedar shavings versus eucalyptus , or corn stover and harina versus eucalyptus and potato stems . Kind of fun to see what emerges. It is different in every area and it is designed by the producers acting in response to their own cultural epicure in balance with their own resources and indiginous botannical knowledge. Generally there is the flame up period for accompanied by a darkening of the surface then a die back into the coal stage . One can of coure jiggle the briquettes to remove the ash and this is usually done. The trick with teh briquetes, is to assure that the jiggled briquette sheds its ash well beneath the embers in such a manner as to not block the air flow from beneath. This is accomplished through the use of a relatively coarse 1.5" to 2 " square grate or the equivalent, set about 2 inches above the floor of the stove. One could make the grate coarser such that the ember itself will fall down after a few minutes into that stage of the burn. This allows maintenance of the flame stage by simply adding new briquettes atop the embers a the right time. Because the ember stage is effectively generating radient heat ,it requires /is very sensitive to distance from the cooking surface. If it were easy to effect a rising grate which one would operate with a counterweight such that as the briquette mass was reduced, the grate would lift it closer to the pot , this would be the ideal. Accomplishing such.a feat reliably and economically in a development environment is another story. The usual practice is to simply toss in a few more briquettes and or to adjust the recipe to the heating or cooking application. At their average cost of 2.5 us cents and 2 to 4 per person per day consumption rate (measured over the six nations we have extended the technology over the past seven years from sea level to 11,500 ft) we usually can equal or beat the price of wood and charcoal, so such niceties are a counterbalanced rising grate are not exactly critical to the adaptation process. By blocking the hole I should have more accurately stated that we simply do not create a hole by removing the center pipe from the mold, making a solid cylindrical briquette. As concerns Ben Bryant's publications, I would kindly refer you to Dr. Ben Bryant's email address: fibro@uswest.net As former professor emertitus of the College of Forest Resources at University of Washington, I am sure he could provide you with a list of publications on the subject. My first contact with Ben began in the late 1970's where I had read about his work in a Volunteers in Technical Assistance publication whilst manageing a 7 yr long Appropriate technology project in Arusha Tanzania. four nations and five assignments later I had subsequent reason to apply his ideas in Malawi while residing there from 1994 through 1999. I maintain a working relationship with Ben to date through ongoing project extension and design work. with his life long immersion teaching and research in natural materials , he is a well respected technical advisor on our foundation's board. With respect to Phase changes : We begin with a slurry of between 15 and 25 % fibrous solids and pith (and in the case of sawdust or rice husks, granular material) in water. the press dewaters this mass. Assuming the right permeability , combined with the right elasticity /plasticity the mass is dewatered, randomly aligned and interlocked fibers, to result in a damp mass which will then be reduced under simple open air drying conditions in four to six days to about 1/3rd its "press-exit" weight. The mixture is obviously a liquid but once dewatered behaves as a solid--al at ambient temperature with this method. This process incorporates a compound lever press which has a practical operating pressure of about 2000 lbs +/-500 depending on operator strength. Tests under hydraulic rams with 5 times this pressure do nto significantly change the nature or strength _OR DENSITY of the final product. In fact not until one increases pressure ten times or more does one begin to see evidence of a pahse change from solid cake dewatering to resin release and literal flow of resinous materials. This is what I call a phase change form solid to plastic if nto liquid. The latter process might make sense in an urban dense population area, and it implies such an increase in cost and other production factors temperature control, precision in the ram tolerances, maintanance, training, etc, that it does not make sense where the objective is to generate employment amongst microentrepreneurs. As to whether Seif or Patricia, Nestor or the dozens of tohers would feel like jumping in to support your curiosity , you might have to first establishwhat we are taking for granted in this news group: Ie., that we are acting out of goodwill and in the interest of improving the science of the process for the common good. I am assuming this is what Paul Anderson in Mozambique is now attempting with a local and indigenous population, although he is riding only on a few emails to guide him in the effort. Patricia Ngari runs the Kangemi women empowerement center, in Kangemi, just outside Nairobi (I'm sure Elf knows her) . Nestor Velasquez is the project site manager in Cusco Peru, Seif is or was a site manager in Mangochi district, Malawi. As to Els' experience in Niarobi, I do not recall him when I began in East Africa in 1974. I have see nhis briquettes and he has a very good product. His market is for the urban areas and is being developed as a bursiness by him which is commendabel in nairobi these days. Our two project s in Kenya Kangemi(above) and prior to that in Makueni are of a different focus. We are trying to generate income while providing a rpoduct which competes with fuelwood and charcoal. It cannot be as hot as charcoal as it has far to little carbon.(In Bamaco Mali, where carbon dust is abundant and the briquettes were made of up to 45% charcoal dust, the resulting briquettes were in fact far superior to charcoal but that was urban Bamaco, not rural Kenya, where the sites were distant from the 'fines' as byproducts of charcoal production). It can however compete well with most kinds of fuelwood in use in these sites and that is why we sought them out. Well family is coming in for the fourth of July here, so have got to fire up grille (If you've ever tasted a chicken leg roasted over briquettes made of cedar fronds and junk mail, You will never go back to mesquite !) Anon, Richard Stanley - Stoves List Archives and Website: http://www.crest.org/discussion/stoves/current/ http://www.ikweb.com/enuff/public_html/Stoves.html Stoves List Moderators: Ron Larson, ronallarson@qwest.net Alex English, english@adan.kingston.net Sponsor the Stoves List: http://www.crest.org/discuss3.html - Other Biomass Stoves Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml For information about CHAMBERS STOVES http://www.ikweb.com/enuff/public_html/Chamber.htm From kchishol at fox.nstn.ca Tue Jul 3 13:08:41 2001 From: kchishol at fox.nstn.ca (Kevin Chisholm) Date: Tue Aug 31 21:36:58 2004 Subject: [Fwd: [energyresources] Sustainability plans] In-Reply-To: <3B415DBA.FA47982E@cwcom.net> Message-ID: Dear Thomas ...del.... > Dear All, > > Opinions vary as to when first oil, then natural gas and fnally coal > will run out You assume that we will run out of oil, gas, and coal. We will NEVER run out of gas, oil and coal, and that is not an opinion; that is an absolute fact. What will happen is that as these resources get scarcer, their prices increase, and then it becomes worthwhile conserving. but certainly we cannot go on burning four times as much > oil as is being discovered for ever! Of course not. What you are doing is makint the same mistake that the Club of Rome did: linear assumptions that don't recognize non-linear changes in demand as a result of increase in prices. In that and the broader context > outlined in this forwarded message (sent to the 'gasification' but not > to the 'stoves' list) we are going to need stoves as never before. > > I hope you find it interesting. The posting is excessively philosophical, and the well meaning gentleman has fixed views that are not open to discussion. The Bioenergy List was occupied with such discussions, and they seem to have accomplished very little. Is it possible to stick closer to the design, construction, and testing of stove systems, and to reserve philosophical discussions about the World's Energy Problems for other venues? Kevin Chisholm > - Stoves List Archives and Website: http://www.crest.org/discussion/stoves/current/ http://www.ikweb.com/enuff/public_html/Stoves.html Stoves List Moderators: Ron Larson, ronallarson@qwest.net Alex English, english@adan.kingston.net Sponsor the Stoves List: http://www.crest.org/discuss3.html - Other Biomass Stoves Events and Information: http://www.fsec.ucf.edu/bioam/ http://solstice.crest.org/renewables/biomass-info/ http://solstice.crest.org/renewables/biomass-info/carbon.shtml For information about CHAMBERS STOVES http://www.ikweb.com/enuff/public_html/Chamber.htm From adkarve at pn2.vsnl.net.in Tue Jul 3 20:40:27 2001 From: adkarve at pn2.vsnl.net.in (A.D. Karve) Date: Tue Aug 31 21:36:58 2004 Subject: Briquettes with holes In-Reply-To: <000301c1029b$b47f1ba0$5c7de13f@computer> Message-ID: <000001c10424$19b96a00$5d8ac7cb@vsnl.net.in> A non-text attachment was scrubbed... Name: not available Type: multipart/alternative Size: 0 bytes Desc: not available Url : http://listserv.repp.org/pipermail/stoves/attachments/20010703/ff8444e6/attachment.bin