Nowadays, folks are all jazzed about putting charcoal into their garden soil.
But, as a fuel: what's so great about charcoal?
I see that when they make it, it looks like they are burning it with a tarp over it. What is the mission and how is it accomplished?
Also, it was used as a component in the making of gunpowder prior to the invention of smokeless powders at the end of the 19th century.
Charcoal under a microscope looks like a cratered, cracked landscape. It has lots of surface area.
charcoal is created when wood (or woody material. I have seen charcoal made from corn stalks and the like) is heated past the point of gasification without providing it with enough oxygen to ignite the gasses. I have seen it made over a wood fire in a steel pipe that is capped at both ends, but has a 3/4" hole in one end. Once the fire gets raging, the gasses inside the vessel are expanding and escaping and once that gas ignites, it blows a pretty intense flame. What's really interesting is that without adequate oxygen inside the pipe, the pressure pushes out the oils and gasses for ignition, and what's inside actually just "cooks." When the flames blowing out of the hole start to wane then it's time to kill the fire as what you have is practically pure charcoal. You will want to let the whole thing die down and cool. ALso be careful when removing the charcoal as charcoal powder is semi-explosive around an open flame if its in the form of aerosol (in much the same way that grain dust or flour will cause dust explosions).
Now, I think it's apparent that all that expelled gas being flammable could have uses other places, like in running an engine, or stored for cooking fuel later, etc. In fact that gas can be used in a modified combustion engine and is referred to as "producer gas" or "wood gas." However, there are a lot of tars and heavy oils in it, so it has to be filtered before you get anything very refined.
At any rate, the making of charcoal is relatively simple. Plenty of heat, shortage of oxygen, and you're good to go.
I am curious to see what a combination of powdered charcoal, rock dust, and compost tea would do to a growing medium. I may be pulling my cabbages out with a tractor....
Looking up masonary stove is great to. and the easiest are the mud rocet stoves as far as i can make out drtv rocket stoves.
Hydrogen weighs more than carbon for a given fuel energy, anything less dense than a box of diapers is un-economical to ship by modern methods, and charcoal for soil is "half-baked" compared to charcoal for fuel.
Yes, atoms of hydrogen are lighter than atoms of carbon, but each one only forms one bond, and the energy available is just the difference between bonds within the fuel and bonds in the combustion products.
Just as whiskey can be a value-dense way of transporting corn to market, charcoal burning removes hydrogen and oxygen, so that a kilogram of coal burns for many more joules than a kilogram of wood. Which was very important before the industrial revolution.
Unfortunately, a fuel-joule of charcoal also has a lot more volume than a fuel-joule of wood, and the comparison is even worse between charcoal and anthracite. That means running a barge or rail car or truck with less weight than it was designed for, and paying more for shipping. (By the way, the reason I mentioned disposable diapers is that they're engineered to be as bulky as possible without increasing shipment expense, because paper pulp is so much cheaper than super-absorbent polymers).
I read somewhere (I think Bungay's Energy, The Biomass Options, Wiley 1981) that the Brazilian coal mines and iron smelters are separated by high enough mountains that plantations of eucalyptus are grown near the smelters and processed into charcoal. I hear it's much better than coal for refining steel, if you can afford it.
The traditional way to burn charcoal, which I hear is dangerous even if done correctly, is to build a bonfire in a pit and bury it as it's burning. There are also lots of wood-gas stove designs on the internet, some of which are designed to produce charcoal. The notion of a lozenge tin can work at larger scales, too: I've heard of using a paint can, and one can even build a large retort. http://www.instructables.com/id/How-to-Make-some-Charcoal/
Last point: Microbes seem to do better on charcoal that still has some hydrogen, and even oxygen, left in it. People working to re-create traditional terra preta techniques find they do better with incompletely-charred charcoal.
I knew a Chinese apparently autistic tramp here in the square beneath my house, I used to try to help tramps, who used the rocket stove system to cook with.
youtube videos maybe don't give you such precise instructions as goggle articles but you see people making the things, they fill in on your information a bit, make it easier to believe. The truth is when i am in a looking for information fase, i end up spending an awful lot of time on it. I try not to waste time on it but if I am looking up something that has to do with my prime interests it takes time which everway i do it. Books are the same, no one book has all the information and reading them is slow. Videos look easy but you end up spending hours looking at them, you also learn.
I haven't ever looked into charcoal making and i don't understand the information i came across when i was looking up wood gasifier stoves. I thought you made charcoal in long slow burns under peat and here they are producing charcoal when they have fast burns.
Before i looked at the videos of the looking at the drtv rocket stoves i had read a lot on masonry stoves in google, so maybe it was easy to understand because i had been reading about similar things and I had spent some time looking up videos of mud ovens, pizza ovens, Moroccan ovens and such.
I have just watched, the hybrid stove two cooking with biomass.of lannyplan. In lots of his work you have to really look hard to see what he has done but one video he shows you how to make his, -the green pail retained heat cooker-. That is about hayboxes another great topic. As a woman i really like a person taking me step by step through what is not usually a woman's type of learnt skills. I also just like seeing different people anyway. I like the solarcookingnuts videos, she is creative and a woman, i think she might be on this sight, her name in youtube is LoL. i saw there was a lol on some thread.
To give you more directions i like, I like larry hartweg, zed master, clean energy in harmony with the universe, and michael strizki, hydrogen powered home.
How masonry stove etc. work
I started looking up masonry stoves because i had always wondered about the stoves on which the protagonists of Russian fairy tales slept all day infuriating their mothers. They the Russian stoves turned out to be ecological.
It seems that smoke is a good fuel but as in normal fires, it spreads out and cools as it rises, it does not burn. In a masonry stove the smoke instead of goining up a chimney goes out the back of the fire box into an upperchamber sometimes into a side chamber, the way out of which is at the front so it snakes through various chambers,and it cannot expand too much just enough to get full of oxygen and the chambers get hot and as you burn a very hot fire, you build it up hot, the smoke well heated starts to burns in all the expansion chambers, which means less harmfull smoke goes into the air the harmful bits get burnt out of it.
You also bring in air from outside and bring it in so it passes under the fire box and warms on its way in, plenty of oxygen is the other requisite for burning, th eequation for burnign is, organic material, heat and oxygen. This way of burning wood uses very little wood as is apparent in some of the wood gasifier videos or rocket stove ones.
The thing is, that you don't normally want a short hot burn, you want to keep your room warm all day , so, what they do is to have a lot of masonry brick or stone or clay all round the fire box and round the succeeding chambers, this masonry absorbs and holds the heat though the masonry is thick enough to prevent the stones from burning you. It is like an agar i suppose. It lets off the heat slowlyall day and night into the room when the fires gone out, it can take these stoves a very long time to cool down.
The Finnish stoves masonary stoves are soap stone, which they say is the best and is very smart. You can order them and make them up at home if you are rich enough. The normal way to heat with a masonry stove is to light a fire in the morning for an hour or two and then not again till the next day unless the weather is very sever and then you can light them again in the evening for awhile. You can also have a oven embedded in the masonry and a water heater.
The rocket stove or wood gas stove are the poor mans or trekkers version of masonry stoves, their stoves use the same principals because they enclose the smoke and have a good supply of oxygen they burn the gas coming off the wood. Burning the wood gas enormously decreases the amount of wood they need to bring water to the boil or cook with. They use just a few bits of wood to cook with, so they need very little wood, and they are constructed with tins materials at anyones reach. A few tins, the sort you buy tinned food in.
In lanny plans cooking of pinto beans, he first uses the wood gas of his bits of wood and then when thats exhausted he changes the make up of the stove a bit, so as to cook with the charcoal he has created and then changes it again insulating the pot so that the beans go on cooking in what he calls a retained heat mode, he changes the set up, places his saw dust walled special box over the whole, making it into a a retained heat cooker, that in the old days was called a hay box.
I have tried cooking beans in a hay box and they came out really well. You bring them to the boil and boil them for ten minutes to get the bean heated through and then put them in a box full of cushions and leave them there for a few hours and they cook. At least they did in the in the first stew dish i did them in which was a clay french marmite and seemed to hold the heat really well. You can bring them up to the boil again when they're done and boil them a bit just to make sure you kill of microbes. There, i hope i have increased permiculture and such putting a lot of information within lots of peoples reach. When you ask questions paul wheatcliff i always imagine you are pumping the writers on your threads. I reckon you want us, not you, to explain things. rose macaskie Madrid.
Excellent link! Thanks! And it teaches a bit about kaowool- that could be useful for other projects!
rose macaskie wrote:
Paul you said you had looke dup the videos i had suggested on making charcoal and didnot understand them so i have looked them up again and tried to find the most explicative try, - lets make some wood gas1, Hiramcook-, or -simple wood gasifier- chadphil. these two are made to demonstrate the theory, not so that you know how to make outdoor hobo stoves.
Are you suggesting that I use some of these phrases as search terms on youtube?
When you ask questions paul wheatcliff i always imagine you are pumping the writers on your threads. I reckon you want us, not you, to explain things.
Well, I do worry that I gab too much.
In this case, this is an area I know very little about. The stuff I seem to find seems to complicated and I suspect that there are much easier ways - I just don't know what they are yet.
You just put in "wood gasifiers" and you will get a whole set of videos and will get to the ones i have given you if you sit through several videos, i just chose the ones i thought were would let you understand the principal of wood gas in my last letter the others are really about how to make hobo stoves and wood gas principals are secondary and you can only glean them.
As to why not use just the gas, they do for cars, they did during the second world war and some crazy folks are trying it now, you get trunks with tanks on them full of wood chips that are burning using down draught, i don't understand how they keep burning but they do, and the gas is channeled off the barrels into the engine and used to drive the truck!!
What i want is a lovely masonary stove to warm my house cleanly nearly and to spread a gently steady warmth around with very little fuel and they can be really attractive its like having a castle in your house.
I decided last summer that instead of spending the whole time writting what i was writting, as it was the summer holidays, I would let myself look up all this stuff and solar cooking, it is very time consuming. It means i can give you the phrases theat wil let you in quicker.
For using the gas, well really the first article when you tap in wood gasifiers on you tube is the one to look at first, maybe, but the phrase the crazy jefferson county group of men who made the video use as a title is, gasifier stove, they are, praidiedf and then you can run your eye down the choices at the right hand side of the main video and chose one of some crazy person running his car on wood gas by clicking on the one you want to see, but a frase for such, if you prefer it, is firing up the wood gas truck, this video is by old planner. rose macaskie.
In other words: how much wood and effort would there be to propel my car, say, 300 miles?
In poor countries they don't have chimneys in their houses for the smoke and they get ill they get asthma and bronchitis and even die of these illnesses. We have big chimneys, maybe because we at some point felt that putting smoke into the air was a clean way of disposing of it, now we know that smoke in the air is not a good idea, may be, it should be lead of into a smoke room where it could accumulate on the walls and then be scrapped off and stored. I have no idea what happens to carbon for instance if it does not go off into the air, I just wonder.
Here they suggested using, or rather, have started in some places using the pruning of olive trees to make bricks of biofuel. They turn them to saw dust and stick the saw dust together into sawdust logs.
They leave the earth below olives bare because, i suppose, they imagine vegetation will compete with the olives for nutrients, grass at any rate dries in summer and does not in this hard season compete with the trees for nutrients. The trees are severely pruned so their leaves can't aport much organic matter to the soil and then they turn what they have pruned off the trees which would before have gone to the live stock into biofuels. What is there left after all this to form soils in olive grooves and probably in orange grooves and lots of other orchards? Did they always leave the soils in olive grooves so bare i wonder? Do they use herbicides now days in olive grooves, they certainly do where I go though there are no olives there? When will the soils collapse In this sort of regime even for such a hardy, dry climate, bad soils, tree, as the olive.
The same is true of grapes i saw a bit of video of making a German wine a reisling i think, in which the soils had not been left bare, may be it is not necessary to leave soils bare under grapes and so soils could be bettered in vineyards through natural methods. rose macaskie.
paul wheaton wrote:
Suppose you have the contraption to get the wood gas out of the wood (and thus leave charcoal behind), and you had your car converted to being able to run on wood gas .... I wonder what the miles per effort would be?
In other words: how much wood and effort would there be to propel my car, say, 300 miles?
The book I cited before says about 50% of the energy can be extracted as liquid fuels by existing pyrolysis technology. One Google result for the heating value of generic biomass is 17000 kJ/kg, so a quick calculation shows 142 kg (a little over 300 lb.) of wood would be needed to produce liquids with the energy value of a gallon of gas.
That sounds like serious effort to me.
Lastly, the book talks about Argentina, not Brazil...it's on page 120.
so a quick calculation shows 142 kg (a little over 300 lb.) of wood would be needed to produce liquids with the energy value of a gallon of gas.
Monkeying with 300 pounds of wood vs. 1 gallon of gasoline.
No wonder not many people are fooling with this.
It was a tecnology they used for fuel in the war, not a green method of driving, looking at all the wood gas tecnics helps you understand masonry stoves which are a clean burn and use very little fuel. I dont know how much fuel a car run on wood gas uses.
I don't approve of biofuels, they use organic matter that could go to bettering soils without talking of using up food sources but if we are going to burn wood, wood stoves which burn the wood gas, smoke as well as the wood and store the heat, like rocket stoves, are more efficient than others, they use less fuel, rose .
Automobiles consume stupendous amounts of energy. And they need that energy in a concentrated ("high-quality", in thermodynamics jargon) form.
Heating a house can consume a lot of energy, too, but can be accomplished with very diffuse energy: the warmth from any object over 40 C is fine.
In that vein, I could imagine tending a woodlot, collecting some portion of the wood it produces, and putting most of that into a pyrolyzer that disperses 30% of the energy ("waste" heat) into my house or some other needful system, stores 10% as gas for cooking (bubbling it into a methane digester for storage, perhaps), saves 20% as liquids to replace part of my transportation fuel budget, and leaves the remaining 30% as insoluble carbon, to host soil biota and absorb twice its weight in carbon as my garden's humus matures.
As some pyrolysis equipment companies have discovered through trial and error, systems fueled with biomass work best when they aren't optimized around one particular function. If you have some extra wood, it may be worthwhile to use equipment that processes some of that into a denser form, but we can't drive like we do today on wood or grasses.
I don't think biofuels can all be lumped together. I don't approve of sperm oil lamps as the standard artificial light, but I think the occasional campfire is OK.
Do you need more or less wood to feed an engine with alcohol than with wood smoke, I suppose the question is, do you need more vegetable matter to fuel cars with the gases that come off alcohol or the gases that come off wood when heated. I am not a scientist, you can smash me on this one. Are alcohol or the oil that vegetables produce, the only liquids that are made to use in cars or are there others? Have you wanted to say what you say quickly, so as not to bore everyone and said it so quickly that you are difficult to understand?
Why use vegetable matter that could go to better soils when you could use wind, wave or solar energy.
If you use solar panels, don't you also shade the land in the desert, maybe this shade could make the soil under the panels usable for the growth of plants. agri rose macaskie.
The best source I can recommend for a quick but correct study of thermodynamics is called "Warmth Disperses and Time Passes," ISBN-13: 978-0375753725.
A somewhat shaky definition of thermodynamic "quality" (tailored to those with no thermodynamics training) is the temperature that a source of fuel produces most naturally. Smoke tends to burn at a higher temperature than grain alcohol; it is "higher quality". Similarly, kerosene (jet fuel) burns slightly hotter than gasoline (aka petrol, benzine), even though it is easier to refine; this gives jet engines a greater theoretical efficiency than spark ignition engines.
Solar panels have a tremendous amount of energy embodied in their manufacture. I believe they should be used to power our electrical grid much more than they currently are, but they do not produce engine fuel. Wind and wave power do not, either.
A huge amount of capital equipment exists that is not designed to run on electricity, and unfortunately many people's lives depend on that equipment's continued operation. In my opinion the best thing for the environment will be to continuously search for the lowest-impact and least-centralized mix of fuel that can be provided at a given location and time, to allow a transition to sustainability with a bare minimum of starvation and violence.
Mesquite trees shade the desert as well as solar panels do, but might be produced with less pollution.
The three major improvements to soil due to biomass that I am aware of are: energy to feed soil biota, trace minerals, and the habitat offered by stable carbon (humus). A well-designed biofuel system would contribute fuel to the global transportation network at a partial expense to the first item listed, but would not necessarily reduce the value of biomass for the other two items listed. In fact, pyrolysis may produce a greater weight of stable carbon compounds than composting, especially if the char is of a pore size and chemical nature that is conducive to a rapid buildup of mycelia within its volume.
Two promising biofuels that I think get too little press are methyl acetate (i.e., vinegar neutralized by wood alcohol) and butyl alcohol, both of which are higher-quality fuel than grain alcohol, can be produced from cheaper feedstocks, do not absorb moisture from the air, are much less toxic than gasoline or diesel, etc.
One scheme for fuel production would be to run pyrolysis at a temperature-time profile that produces enough vinegar to neutralize the wood alcohol generated, then carry out reflux and distillation to produce methyl acetate fuel and a few useful byproducts. A slightly less toxic, equally useful fuel is ethyl acetate, in which grain alcohol (from whatever source) is substituted for wood alcohol. A blend of methyl and ethyl is less toxic than the proportion would suggest, because the metabolytes of ethyl acetate are a good antidote to the metabolytes of methyl acetate...as in so many things, a mix of sources has some surprising benefits.
Using difficult vocabulary is one of the prime ways of maintaining class differences. It is a way of being aloof, of marking differences, of making people scared they could never understand what can be explained to a class of ten year olds.
I can't understand the wikipedia article on thermal dynamics the first time i read it, nor the second but looking up some of the things mentioned in then article i begin to understand it and albeit two years later it is possible that it has become an easy subject for me. For the young two years seems an eternity but they soon go by and you find that you can explain things better which is great.
I don't suppose the change over to solar or wind would be too quick anyway so thats not a worry, the worry is it being too slow. It is going to be a big industustry, better to be the ones selling solar energy objects than the ones buying them. We don't want china to win that race. Think how dangerouse it is, look up "fulgarant concentrateur solair parabolique" for a quick idea of the advantages and disadvantages of solar. It is in french but you don't need to understand it. Better have western solar cookers than chinese ones, that is racist, better earn the money us than them. Thats mean, but china is worse than normal for brutality as a nation.
The out of work don't usually get viollent, Taser them a bit and they will get used to living in tents. Get a good social security system working and you can make the necessary changes without doing for people. "To think we buy gowns lined with ermine for dolts who can't or wont determine what best will rid of of our vermint". If they are well enough looked after, lots of them will become productive. The whole system is geared to the poor not complaining and it normally works, the difficulty is to get them to fight not to stop them. Bad town planning makes for violence. I read an article about an architect who was chanign a poor part of london to get families living in it so tha tit would not be violent.
As we want to critisise them the chinese on civil rights and paying african workers in the congo properly, we had better clean up on our own act.
The death sentence does not look so cool if you imagine that you are ruled by the chinese.The church does not support tibetans even though the chinese subject the tibetan woman to forced abortions. The chinese are getting rid of a competeing religion, the first goal is to get rid of buddhists, being anti abortions comes second for the church, what hypocrites they are, it all depends on whats good for them.
We got through the first and second world war, the communists in England decided they could break the country going into the car industry and doing for it with strikes and though they broke the car industry a bit the english did not go down the drain. The standard of living for the poor got much better during my teen age when the comunists were breaking the car industry.
Can you whatch the bengalies sink and say you don't want change? agri rose macaskie.
For example: most of the people I know do not have separate concepts for straw and for hay. The two ideas are mixed together, and the two terms are used interchangeably. If I talk about gardening with them, they are sometimes offended if I distinguish between the two. But I don't do this to sharpen the distinction between their class and mine; I do this because the distinction between straw and hay matters in a garden.
I am very sorry if I have offended you, but I felt the need for a particular term in this particular context.
No energy source will replace fossil fuels entirely, but I think context is important in choosing how to adapt to their new scarcity. For example, there are huge kites (commercially available now!) designed to tow modern cargo ships, but those ships still use some fuel. There are governments that would go to war to keep cargo ships moving.
The transition will not be quick enough, I agree.
The brits seem to master the teqnic of making carcoal that is have the coppiced wood lands were created for the production of charcoal for home heating, glass & metal making, the forest was managed by these company's to ensure a supply of material for thier industries. that ended with the use of Coal and then Petrol
I feel with the appearance of the end of oil we will return to the use of wood for home heating and eventualy for use by industry we are close to this I also fear of deforestation due to the use of wood and it not be replenished we are talking mass use of biomass could be big in the use of our forest lands. management will need to be used
This could be a different string maybe I ll start one
paul wheaton wrote:
Here is an interesting video on making charcoal: http://www.youtube.com/watch?v=l_ZeO1bUiww&NR=1
Same method, as interpreted by MIT:
She clearly doesn't know what she's doing as well as the guy in the other video, but she talks about it, which I found helpful.
Kind of funny when she switches over to talk about briquetting, and all the efforts to simplify her machine. Also interesting that she has people drilling holes in tables, when they might just choose to work on a short stack of pallets.
Be careful cutting the metal that drops down on top to form a seal! That should go without saying, but apparently it didn't to me...only a scratch, but still. A coffee can that had a peel-off foil top, and so retains a lip, makes it easy.
Also, it's worth putting a fair amount of air holes in the bottom. Mine could've used 3 or 4 times as many...only about a nickel worth of area all together, I'll drill more before I use it again.
The MIT prof is right: you learn a lot the first time. I stopped the process after only 10% had charred the first time. I loaded that batch back up, and got it 90% done the next time. That's about what I had intended, since the charcoal is to be a soil amendment.
She's also quite right that it's important to have vaguely uniform pieces. One thing that's possible with a small setup, but not hers: the fuel can be stirred as the process goes along, to make things more uniform.
Even the wood that doesn't char is noticeably weakened by the heat. I could see a 40% char being worthwhile to save some effort in chipping, or just to speed decomposition. All but one piece broke up easily when hit with a Christmas tree trunk against concrete.
I'm happy to answer questions, too!
before putting the lid on and sealing the based and top with sand.
The chap in the B&W video has a huge amount of smoke - it means that the
wood is still off-gassing moisture etc.
If you put the lid on and there is smoke, draw it aside to let it burn more.
Using a lid with a chimney such as this
allows for secondary air to enter in order to burn cleanly (a la rocketstove?)
I have used drums for making huge amount of charcoal.
just break up sticks and stuff in the drum. the drum helps to dry out the sticks.
when it's full it's time to light up.
Please soak your charcoal before crushing it if it's to be put into the soil as biochar.
Easiest way to crush is done by putting in a bag and mashing with
something heavy like a log.
see MAKING BIOCHAR: with Peter Hirst of New England Biochar
I always read that it's the oposite - lower temp.
Theres a lot of conflicting information on the web.
While I'm aiming at the lower temp terra preta type char,
biochar as by Peter Hirst may be more likened to activated charcoal.
Very shortly you will see lines of flame from the holes in the lid, accompanied by a roar. It is very important to have a good draft and that the gasses coming out of the can burn or you are polluting the atmosphere with very unpleasant stuff. I took one batch out too soon and when I took off the lid it was pretty scary what the smoke was like, so don't be in a hurry to get it out, let it do its thing. When it IS done the material will be about a third smaller than it was but looking like a smaller black version of what it was when it went in, and it will be easy to crumble. This is basically almost pure carbon.
A couple of points..IF you open it up too soon, even if it SEEMS cool, it MAY catch fire when the oxygen hits it, so don't dump it into anything flammable even if you THINK it's cold enough..I dump mine into charged water to cool it off for sure & leave it to soak for several days. Worm compost tea would probably be better. Otherwise, the carbon should be aged, some say for several months, others say for up to 2 years. I am trying to short cut the process. .The other advantage to the water bucket is that this material can be very dusty when it is broken up, I just let it sit in the water and pound it with a length of 2x4 and there is no dust at all.
ANY carbon based material will make this charcoal. It is however very important to make sure that all the vapours from the material are burned or the pollution is horrendous.
Some use an afterburner to accomplish this; I just keep an eye on the lid vents and push some extra lit fuel around it if they seem to be not burning as they should. When no matter what you do there seems to be no more gasses escaping it's likely the pyrolysis is complete.
This is just my experimentation based on what I have read and seen from sites I trust; there is a lot of stuff on You Tube which is a bit irresponsible imo.
I just started experimenting with this this spring and am trying to find someplace to send samples to find out what the cardboard leaves besides carbon, so as to know about using it as a soil amendment. It seems to me that there is a possibility of turning some of the stuff that goes into landfills into a usable material and that has more interest to me than growing forests of trees just to turn them into charcoal. Several companies are doing that already.
It also seems to me that this could easilly be incorporated into a greenhouse type environment ..if you captured the heat with say a water line inside the unit which then travelled through water barrels as a passive heat design it could mean that with a minimum of wood (even from broken pallets?) you could 1)heat the greenhouse for virtually no money, 2)help to deal with the mountains of waste AND 3) create a valuable product to act as both a carbon sink (buzzword these days) and a soil amendment.
It has also crossed my mind that it would be interesting to hook this up to a sterling motor..who cares if the efficiency rating is low when what you are getting is usable electricity as a by product of a process you are already using? maybe use the electricity produced to power led lights for the greenhouse?
A link or two..Geoff Moxham (first link) is dead now from accident but he worked with biochar for a number of years
The wood gas thing..there is a US Government site with instructions on how to make a wood gas engine; I have neither the tools, the inclination nor the ability so I haven't kept the link.
Tell me how it all turns out. Here is a tiny ad:
The Earth Sheltered Solar Greenhouse Book by Mike Oehler - digital downloadhttps://permies.com/wiki/23444/digital-market/digital-market/Earth-Sheltered-Solar-Greenhouse-Book