Masonry Mass Heater powered by pyrolysis

I note that there was some conversation of transitioning from combustion to pyrolysis to provide the thermal energy to heat a masonry mass. I was asked to post this comment:

Paul,

I find the rocket stove mass heater of interest. However, it appears to be a combustion device
that depends on a narrow range of fuels -- mainly wood. As such, it accelerates the natural
carbon cycle. That is, the carbon in the wood, if left alone in nature, would take decades of
decay before it fully returned to the atmosphere.

Combustion rockets it right back into the atmosphere in very short order.
What I would like to see is a pyrolysis unit heating the masonry mass and
the resulting biochar added to the compost on its way to the garden. This
will retard the carbon cycle by keeping the carbon out of the atmosphere for
a much longer time than the natural carbon cycle. And MUCH longer than
energy systems based on combustion.

Additionally, the pyrolysis system could use many feedstocks and might even
dispense with wood as a heat source altogether.

What progress on this transition as been made?

Full disclosure: I am working with Jerry Whitfield, the inventor of the first practical wood pellet stove in 1984, on a very scalable continuous feed biochar reactor. We expect to show a parlor stove rated at 25K btus per hour in late 2012. We will also have larger units for industrial applications. We hope to see the parlor stove used in energy+ homes, homes that create more energy than they use, in such a way as to integrate heating with gardening with cooking & eating. Our hope is to arrange configurations of these homes that will creatively implement ideas from permaculture, co-housing, transition towns, carbon negative energy, etc. For the record, in Massachusetts, 11 energy+ house are currently under construction and 100 more are in the pipe line.

All comments, suggestions, and inquiries are welcome.

Cheers,

Jock

Could you add a link to something that explains what you're up to? I think for most of us who want rocket stoves, we will use wood that is produced incidentally on the farm. Wood that I recycle would be burned otherwise so my using it adds nothing additional to the atmosphere. Let's all gang up and pick on oil and coal. Compared to those, a rocket stove powered by windfall is a huge improvement.

My understanding is that biochar requires higher temperatures than charcoal. 900 degrees vs 400 degrees, something about the microstructure of the end product. To achieve these temperatures without combustion, focused sunlight could do the job-a fresnel lens. To also heat masonry, this sunlight would have to pass through the fresnel and be absorbed by masonry-thats got trombe wall written all over it. To pyrolize biomass continually, I'd think it would have to be small-pellets fit the bill. A convenient feedstock for homeowners would be leaves and grass.

So...homeowner rakes leaves and dried grass clippings, makes his own pellets with a pellet mill, the pellets go into a hopper which continually feeds biochar retort tubes at the focus of a fresnel lens placed in front of a trombe wall. While you are at it, save the gasses produced for cooking and lighting.
or something like that.

Gents,

Many thanks for the comments.

Ken: Worth trying. The gases contain vaporized tars and such that are prone to condensing into a hot mess. Best to combust the pyrolysis gases as they emerge from the pyrolysis chamber. Keeps thing much simpler.

Dale: We are still pretty much in stealth mode and do not have any formal literature at this time. I expect that we will build 4 or 5 of the energy+ houses on our site about 4 miles from down town Boston within the next 12 -18 months. I concur that rocket stoves are far superior to all fossil fuel based solutions. Combustion, however, does accelerate the carbon cycle and is not carbon negative. Why not take the wood waste stream you currently combust but transition to pyrolysis? You'd get all of the benefits you currently get, plus you would be retarding the carbon cycle by sequestering the biochar in your compost/garden? To say nothing of improving soil health etc.

The developer's web site is here: http://transformations-inc.com/

You might find this video on a TLUD heating a retort to be of interest. Thanks to Doug Clayton & Hugh McLaughlin.

http://www.youtube.com/watch?v=Kg95KYrH8PI

For those who want to learn more about pyrolysis, biochar & gardening, and hopefully teach it to others, the Biochar Activity Kit, organized by Doris Hamill of NASA Langley, may be of interest:

http://www.greaterdemocracy.org/archives/1316

Regards,

Jock

biochar is a good idea but can be difficult/expensive to attain. The rocket, though it releases the CO2 quickly, is efficient reducing the fuel needed and keeping living tree's on the land. Biochar would be useful in area's needing soil remediation of some sort. Additionally, efficient combustion has the benefit of not producing methane, a major component of natural degradation which is 20x worse than CO2, and so long as the fuel is sustainably harvested you are only putting back what your fuel takes out. You do have to put out the inorganic nutrients so those aren't lost to the soil but thats true of biochar as well.

Ted,

It is true that biochar is not readily available just yet. This will change quite rapidly, perhaps starting as soon as 2013. Recently, the Sonoma Biochar Initiative took delivery of 11 tons of biochar. So the availability issue is already starting to be solved. Meanwhile, please take a look at Doug's video mentioned above.

As biochar should be mixed with compost before adding to the soil, I expect that the replenishment you speak of is well covered. And of course pyrolysis also solves the methane problem as well.

In any case, the transition from combustion to pyrolysis is just getting started.

Regards,

Jock

well for my take on it being in the pacific north west and our region as a whole being fire aspected? whats the point unless i am in a city? the country side round here is full of charcoal in the soils and all it does is make it so i dont have to add some other amendment. So far I have seen very little to recommend Bio char in our area. my other question is what exactly are you using to create the pyrolisis. there has to be a pretty large or long energy input somewhere.

Ernie,

Glad to hear from you.

I am also glad for you if you live where there is abundant charcoal in the soils! if you follow the postings of Erich Knight, you would learn of many other uses for biochar: aquaculture, animal feed, storm water runoff mitigation, soil remediation for various contaminants, nutrient management on farms, use in latrines, water filtration, and much more.

As for energy, once started, a very simple and easy process, pyrolysis basically sustains itself via a parasitic load on the thermal energy created during the pyrolysis process or on the heat generated by combusting the pyrolytic gases. For example, a simple TLUD could quite easily be configured to power a masonry heater. To learn more about TLUDs, please check out this very simple design:

http://www.greaterdemocracy.org/archives/1393

This video shows how simple it is to get a TLUD in a 55 gallon barrel started:

http://www.youtube.com/watch?v=Kg95KYrH8PI

A few photos of a simple iCan TLUD being used for cooking. When the meal is cooked, you have also produced some biochar for your compost pile.

Well the links are interesting and yes i understand the uses of activated charcoal.
I dont actually see that you are in fact saving much at all; you have a burn of pyrolitic gasses that approaches 100 percent and is still composed of steam and CO2 and you have incomplete combustion of the biomass that you have put in the system, resulting in activated charcoal.
the RMH in some respects uses the same principals however we burn the wood to a fine ash that is mostly pure mineral.
We exhaust steam and CO2 and no smoke when it goes out.
I can see that for some places charcoal could be good in the soils (I have yet to see a side by side done in laboratory controls so i keep giving folks the benefit of the doubt as far as general north american soils).
I can see that Charcoal could be used for a variety of things that would directly benefit human health (like water filtration and sewer treatment. fresh water being of primary concern).
What i dont see is where its substantially better than a wood gas production unit. Or simply taking as much biomass as we can get and simply burying it in a pit. the fears of methane are from methane hydrides and there is absolutely nothing that will stop it when they let go, cow farts and rotting vegetation in swamps produce so little in comparison of what is now leaking from the permafrost layer every hour that its not even on the scale anymore.


The RMH may not produce charcoal but it pays for its carbon output by using pretty much any biomass you can give it (I haven't tried dried mushrooms yet; but Conks burn pretty well) and making the trade on annually produced vegetation.
It seems the biochar might sequester carbon into the soils and such so it would remove some in due time but i still have a hard time seeing that it is a solution in and of itself. I can see it as part of the answer. to actually be an answer the WORLD would have to use massive amounts of forests to convert to charcoal and bury in the ground (eventually it would I assume end up in the land fills. I cant claim the rocket stove is THE answer either.

Now i am not getting down on the tech cause i can see where it can be a great thing but it is an apple and the rocket stove a banana ( I like banananana ---Its hard to stop spelling it) they dont actually compare to each other. I can put the rocket stove ash into a soil and make rhodies grow like mad, feed it to fish and give them a mineral supplement etc. but that does not make the rocket like the pyrolizer stove you have. both ways are an answer to the same problem from different approaches. I will look forward to seeing what you come up with over time and cheer when you get it in code. the I can looks to be a nice simple device that lots of folks can get behind and the Biochar experiment kit looks like fun and i will try some of the experiments with my students against endophitic fungi's and normal soils, to see if there is a difference in the way the I can makes biochar. Sides i always like a bit more stuff to learn about the various forms of fire.

Ernie,

Thank you for your long reply so I will try to respond to a few key points. Glad you liked the links. I hope others will also study them.

1. Biochar is not activated carbon. Pyrolysis does, however, convert basic organic carbon into elemental carbon which is far more resistant to oxidation than organic carbon. Thus burying biochar has a much longer payoff in terms of carbon sequestration than simply burying biomass.

2. I am not sure what you mean by not saving much. Hoever, we do NOT combust the biomass. If we did, it would not be pyrolysis and we would create ash, not charcoal. I would argue that the resulting biochar has far more value than simple mineral ash. Biochar is now selling for between $200 and $1,200 per ton. I do not believe there is even a market for mineral ash from combustion.

3. Question: How well does chicken litter work in a RMH? We can pyrolyize it just fine, altho the biochar does have a high ash content.

4. I concur about the problem with methan hydrates. A very serious problem indeed.

5. I concur. There is no silver bullet. Neither RMH nor Biochar. We need all of the buckshot we can get.

6. As we can use most any feedstock in a pyrolysis process, there is no need to use wood at all. It is a red herring to argue, as Biofuels Watch often does, that biochar is a threat to the forests of the world. Quite the opposite. Pyrolysis, by not using wood fuels, promotes aforestation.

7. All of the above will become more clear when you play around with the Biochar Kit. You will find the collection of references to be most useful. If you have any questions at all about the kit, please ask me and I can get answers from the team that assembled it. I know that Paul Stamets inoculates biochar with mycelium and calls it mycrochar. It appears to be a wonderful combo. He has even TMed the name.

As I sometimes say, I play with fire and put folks in touch with their inner pyro. I really look forward to your results from fooling around with pyrolysis. Do be careful. Even small iCans develop temps around 1,000 degrees F.

Many thanks for a stimulating conversation.

Cheers,

Jock

Hi Jock (and everyone else)--I have been playing around with soup-can-size (and 55 gallon drum size) pyrolysis reactors. What is the purpose of the metal plate sandwiched between the two cans in some of those photos? Is it a concentrator ring? Turbulence-generator (perhaps those are one and the same)? I assume there is a hole in it. How large is the hole?

Had about 35 students building soup-can TLUD's yesterday. Most of them were somewhat successful, with a couple utter failure (I think not enough primary air), but lots of learning and excitement. Unfortunately we left our 55 gallon TLUD under the attendance of a guy who had no idea what biochar's end-goal was, and he let it burn all the way to ash Ah well. Seemed to work pretty well while it was going!

FWIW (mostly for the techno/scientifically inclined)

The what of pyrolysis (had to look it up) is: Heat biomass (that is, more or less, almost any substantially non-metallic, non-plastic mass) really hot BUT do it in the absence of oxygen; keep out oxygen and it won't burn. Result is that "stuff happens" to the biomass (remember, no oxygen, no burning, just really hot) breaking it down into various gases and leaving the remaining solids mostly pure carbon (depending on hot dirty or contaminated the biomass input was).

The why of pyrolysis: From a very brief review, commercial pyrolysis seems to be about the production (from biomass inputs + energy) of liquid or gas fuel with a by product of salable "biochar". The two sites below give overviews of two commercial systems using different methods; but the end results of both are fuel and char. I have not found any info on energy-in to fuel-energy-out ratios but I haven't looked very hard - this is just for conceptual overview. A significant practical +plus+ for many entities is the reduction of large waste mass into much smaller and easily disposable, if not actually salable, material quantities. IOW it's a way to make your garbage disappear more easily and cheaply.

http://pacificpyrolysis.com/technology.html

http://www.btgworld.com/en/rtd/technologies/fast-pyrolysis


Rufus

I am intrigued by biomass stoves that have char as a byproduct of operation.
Char is stable and can be used in a vehicular charcoal gasifier, which is simpler and cleaner than wood gasification. A biochar producing stove that stores heat in a bell or bench could cover a lot of a homesteads energy needs.

Why not design a gasification system that you can smoke meat make biochar and run a generator off a single source of wood maybe Apple smoke ribs with cornstalk biochar with all the exhaust being condensed filtered and running a generator 🤔now that would be cool