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Post by colinsaengdara on Jan 11, 2014 14:31:45 GMT -8
The subject of emissions is one of the most important topics for the future of wood burning. The traditional box stove designs of the past, and the way that we used them, have given wood burning a bad reputation. The EPA rules about wood stoves are designed as an attempt to address the paradigm of traditional wood burning stoves and their testing methods are not effective at determining true efficiency. Basically, a stove is evaluated in a lab under conditions that usually do not reflect how they are used in the real world. Here in this forum, we are designing new approaches to burning wood and biomass, with a strong emphasis on rocket stoves and their various designs. Because rocket stoves have a very high velocity gas flow through the combustion zone they tend to burn very efficiently. Limited extra air, high velocity gas flow, high temperature all contribute to good conversion of biomass fuel to it's eventual products CO2, H20 and mineral (ions I suspect).
The new EPA rules will be targeting particle emissions much more aggressively than in the past. I have not done a thorough review of the new rules, nor have I read the studies that link fine particle emissions to problems in human health. I think it's highly likely that there is a qualitative difference between soot and the various fine mineral particles that are likely to be the bulk of rocket stove emissions. But this would need to be tested.
Emission controls that I am aware of for traditional stoves focus on improving the combustion efficiency. I'm thinking here of catalytic converters and secondary air designs that attempt to reduce the damage of the poor designs of the firebox and the slow burning methods of the user. But rocket stoves (and from here on out, I am referring to a properly designed rocket stove with an insulating refractory firebox and insulated heat riser of sufficient height to allow for complete combustion) already burn nearly all the tars, and once warmed up have no issue with creosote (condensed tars that adhere to inner surfaces). This is a huge qualitative difference in the emissions of rocket stoves that should open the door to different engineering solutions than one would use to approach cleaning up traditional wood stove emissions.
In my mind, a rocket stoves emissions are clean enough and free enough of sticky tars, that one could use a stainless steel mesh filter, or a series of them, electrically isolate them so that one is positive and one is negative to attract the various mineral ions that flow out with the flue gases. Attach one filter to the positive side of a battery, attach the other to the negative side, and see what happens. Some materials like plastics can handle the relatively low temperatures at the exhaust end of a rocket mass system and plastics might generate static charge simply by friction with the air stream. This could be helpful or harmful if placed in the right sequence.
I know that this could be handled by adding power to the system, and I think that's fine for testing hypotheses to see if the idea is viable, but in the end, I wouldn't be satisfied with anything less than a passive system.
There are only a couple of folks here who have the expensive test equipment, but we should be able to come up with homebrew solutions to measure fine particle emissions using small diameter HEPA filters for post emission equipment sampling.
I hope that our community will take the new EPA standards seriously and start to educate ourselves and each other about what they mean, what the science is behind them. I also hope that we can be proactive and look for passive solutions that eliminate the problem altogether. This would be the time to start!
Brainstorming 101
Any and all ideas are welcome. Please don't dismiss ideas too quickly, something that might not sound promising on the face of it may be a subtle solution to another design's shortcoming. I've tried to kick this off with the idea of negatively and positively charged mesh filters but that is just an example. Please offer your thoughts and solutions if this topic interests you.
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Post by matthewwalker on Jan 11, 2014 14:42:06 GMT -8
Excellent post Colin, thank you for taking the time. I don't think any of us have the means currently to measure particulate, but I did learn of one way while in DC. Norbert Senf was kind enough to introduce me to the Condar system, a DIY particulate emissions measuring system. It's fairly straightforward to build and operate, and he has data comparing it to a commercial measuring device and they were basically identical in their results. Let me see if I can find a link here.... Here's the start of the rabbit hole, from Norbert's website: heatkit.com/html/lopezq.htmYou can go for hours from here. Have fun! |
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Post by colinsaengdara on Jan 11, 2014 14:47:39 GMT -8
Awesome Matt! Thanks for the link!
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Post by Dan (Upstate NY, USA) on Jan 11, 2014 16:23:53 GMT -8
I am not sure that I get much particulate at all from my J-tube rocket stove. I have 30 feet of 8" pipe attached to 27 feet of 6" pipe external insulated heat riser. I only find fly ash in the first 7 feet of 8" pipe and I no longer find any fly ash in the cleanout of my 27 feet of 6" external chimney. Maybe I should acquire a fine filter and strap it down over my cap to see what I get after a few days.
I think most of it would be creosote from the beginning of my batch burn before everything is heated up...?
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Post by colinsaengdara on Jan 11, 2014 19:31:27 GMT -8
My impression has always been the same wolf, but according to Matt, Peterberg and the folks at the woodstove decathalon the size of the particles they are discussing are super fine! So small and lightweight, in fact, that they do not settle out of a moving gas stream. So yes, the only way we would know for sure is to filter a sample of your exhaust gas. I started this thread in order not to hijack pinhead's thread regarding the new regulations: EPA Announces New Regulations for WoodstovesThe meat and potatoes of the article: None of this directly effects me - I'll never buy a NEW wood burning stove anyway. But I'm curious: Do Rocket Stoves and Peterberg Batch Box stoves meet these requirements? It's in the woodstoves for heating section. So the concern is that the high turbulence /velocity burn will create higher volumes of small mineral particulates in the gas stream as the organic matrix is pyrolyzed and reduced rapidly from around the minerals. With the regulations eventually going down to just 1.3 grams per hour, I'm pretty certain we need to address this issue proactively. |
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Post by patamos on Jan 11, 2014 22:15:39 GMT -8
Okay. When i read the thread started by Pinhead, the first marble that rattled around my noggin was trying to picture a way of inducing some sort of mirror image (opposing double cyclonic?) venturi effect near the exhaust stack exit. Like what permies do to ionize water. Can't remember the proper name for the effect. But have heard that one can buy little units to install directly in pex water lines.
If some of what is heading out the stack is O2 vapour then at least one of the basic elements is in common. Maybe such a modification of gas trajectories could de/re/counter ionize the matter before it exits...
Beyond the proto-notion, please consider this post a brain fart of an intermediate impossibility....(?)
well being
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morticcio
Full Member
"The problem with internet quotes is that you can't always depend on their accuracy" - Aristotle
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Post by morticcio on Jan 12, 2014 16:54:34 GMT -8
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Post by matthewwalker on Jan 12, 2014 17:33:14 GMT -8
Unfortunately that cat will only burn stuff that is not consumed by the heater. Our stoves burn all the stuff that can be burnt, well, pretty dang close anyway. What's left is inorganic and cannot be burned, so a cat won't help. At least, that's my understanding. I'm new to all this, so for sure I could be way wrong. I do that a lot!
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morticcio
Full Member
"The problem with internet quotes is that you can't always depend on their accuracy" - Aristotle
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Post by morticcio on Jan 12, 2014 18:44:22 GMT -8
I'm not sure either! It is a Dutch company so maybe Peter could find out more? This Swiss design by Oeko is another approach, but requires a power supply. I noticed that the Ecolink product has references in their testing literature to what looks like the Oeko particle animation drawing. |
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Post by oboblomov on Jan 13, 2014 10:30:59 GMT -8
The subject of emissions is one of the most important topics for the future of wood burning. The traditional box stove designs of the past, and the way that we used them, have given wood burning a bad reputation. The EPA rules about wood stoves are designed as an attempt to address the paradigm of traditional wood burning stoves and their testing methods are not effective at determining true efficiency. ... Thank you, Colin, for your clear framing of this extremely important issue. I hope I've not come too late to this discussion. Been thinking about "particulates" a bit since Pinhead's original post. Had intended to do a bit more reading first but it never happened. Just a few ideas from memory. You make the important point that there is a qualitative difference between pollutants of different particle size. This is especially so for particles that are in the one micron range (at least in one cross section.) The reason for this is that all bacteria, disease causing and otherwise, are either round or rod-shaped cells with a basic cross sectional dimension of one micron. Airborne bacteria that get sucked into the innermost air channels in our lungs normally get gobbled up by our macrophages that are slithering around in there. This mechanism works very well and to our good health as long as the macrophage sticks to ingesting bacteria. Macrophages are very efficient at killing the bacteria they ingest, but if they should happen to mistake a one micron sized non-bacterial particle for a bacterial cell, and ingest it, all micro-hell breaks loose for them. The long and short of it is that these macrophages die and our lungs have no way of getting rid of all of the micro-carnage. So, after many, many of these "lethal ingestions" our lungs can be quite a mess. You should be concerned about breathing micron-sized particles, but not overly so. My father-in-law worked for 40 years with railroad locomotives, steam (coal and oil burning, with asbestos flying all over the cab, day in, day out) and later with diesel engines. Probably one of the worst case air pollution environments one can imagine. After removal of one lung and an early retirement at 55 - the silver lining - he enjoyed another 40 years of spectacularly good health! Of course he never smoked. Now the caveats to this post: While I was once a microbiologist of a sort, there are great, gaping holes in my scientific background. I don't know much about human biology, or medical microbiology, for that matter; subjects that the tone of this post might imply I have greater knowledge of. I'm just trying to make clear what I think is going on with particulates and health. A personal concern of mine. Some of you may possess better knowledge and I welcome your input in advance. Take-home lesson: Don't go sniffing (too much) from you near-odorless chimney stacks. obob |
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Post by Robert on Jan 13, 2014 16:41:01 GMT -8
BTW anyone knows how to measure the level of:
CO (carbon monoxide), NO (nitric oxide), NO2 (nitrogen dioxide), SO2 (sulfur dioxide)
will the Testo 330-2 do the job?
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Post by colinsaengdara on Jan 13, 2014 18:03:37 GMT -8
Okay. When i read the thread started by Pinhead, the first marble that rattled around my noggin was trying to picture a way of inducing some sort of mirror image (opposing double cyclonic?) venturi effect near the exhaust stack exit. Like what permies do to ionize water. Can't remember the proper name for the effect. But have heard that one can buy little units to install directly in pex water lines. If some of what is heading out the stack is O2 vapour then at least one of the basic elements is in common. Maybe such a modification of gas trajectories could de/re/counter ionize the matter before it exits... Beyond the proto-notion, please consider this post a brain fart of an intermediate impossibility....(?) well being Patamos, thanks for the input! I confess that I'm not familiar with the permie water ionizer concept. I'll have to go explore a bit to see what you are getting at here. Could you explain a bit about what the purpose of the ionizer is in water systems? Is it for precipitating out excess calcium? Thanks in advance, and thanks for the interesting post! @ Obob WOW! Fascinating stuff! I was never sure why small particles were of particular concern, but you present a compelling hypothesis! I know we are just starting to learn about all the symbiotic relationships between ourselves and the microorganisms who call our bodies "home". I do hope we have a microbiologist in our midst to shed more light on this topic. Thanks so much! Colin |
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Post by oboblomov on Jan 13, 2014 19:08:29 GMT -8
Thanks, Colin. Heard that explanation nearly 40 years ago by a fellow who was trying to figure out how asbestos causes the cancer, mesothelioma. Did a bit of reading today and learned that that what I presented above is still considered one of the mechanisms for asbestos caused cancers. (Probably wouldn't have sounded as tentative if I'd read that before I posted  ) It is also the basic mechanism behind lung diseases like silicosis, asbestosis, black lung and brown lung. All caused by lung macrophages ingesting bacteria-sized foreign particles and being killed in the process. The mass of dead macrophages is then walled-off with scar tissue - a process that diminishes lung capacity. Or so I was told. Macrophages are our friends, normally. They kill bacteria that might cause infections in our bodies. But when they ingest particulate matter (the PM of the EPA), they turn against us and self-destruct, causing big trouble. obob |
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Post by patamos on Jan 13, 2014 20:49:38 GMT -8
Hi Colin, The basic idea is that the double hydrogen electrons in water are ionically bound in the H2O molecule. When water is made turbid, ala splashing on rock at the bottom of a waterfall, many negatively charged hydrogen ions are released. When we absorb these ions into our bodies they have the effect of neutralizing free radicals. When clay dehydrates it releases such H- ions. This is why non-fired clay-based plasters and features within a dwelling are considered health enhancing. This is why a walk in nature after a spring/summer/fall shower can be so refreshing. Many companies are now making devices to ionize water that is coming out of the tap. Presumably by evoking specific patterns of turbulence. The jury is out as to whether some or any of these devises work well. And there is plenty of disinformation from the pharma-corp establishment who would rather we not be aware of freely available (and thus non-patentable) health care products. My train of thought in first posting was, if negative ions can be pulled from water by shaping its flow patterns, and if the turbidity of high velocity rocket combustion is having a similar effect on flue gasses... how might we evoke a dynamic in which the ions rebind with (  ) before exiting the flue? Setting up a slight electrostatic charge is one idea, as alluded to in the discussions from Pinhead's starter thread. I have just been wondering if the power of the fire's draft might somehow be utilized to power a subatomic reintegration in a relatively passive manner. Does anyone know which of the particulate ions are causing the respiratory trouble? ANd whether they are positive or negatively charged? well being pat |
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morticcio
Full Member
"The problem with internet quotes is that you can't always depend on their accuracy" - Aristotle
Posts: 371
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Post by morticcio on Jan 14, 2014 0:27:26 GMT -8
BTW anyone knows how to measure the level of: CO (carbon monoxide), NO (nitric oxide), NO2 (nitrogen dioxide), SO2 (sulfur dioxide) will the Testo 330-2 do the job? It can measure CO. It needs an (expensive) upgrade for NO. |
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) It is also the basic mechanism behind lung diseases like silicosis, asbestosis, black lung and brown lung. All caused by lung macrophages ingesting bacteria-sized foreign particles and being killed in the process. The mass of dead macrophages is then walled-off with scar tissue - a process that diminishes lung capacity. Or so I was told.
) before exiting the flue? Setting up a slight electrostatic charge is one idea, as alluded to in the discussions from Pinhead's starter thread. I have just been wondering if the power of the fire's draft might somehow be utilized to power a subatomic reintegration in a relatively passive manner.