Rocket Stove Gasifier

This post is long and involved. I hope to explain my project well enough for others here to attempt it as well. I am hoping to achieve a sustainable, inexpensive alternative energy source that will allow an individual to provide all the electricity his or her home requires. ROI should be less than 2 years, I hope.

I'm attempting to build a gasifier inside a rocket stove. My theory is that if the feedstock to generate producer gas is not also used as the heat source, then anything organic or patrolium based could be gasified in that chamber, which is heated by the rocket stove. You can't gasify paper products or municipal waste in a wood gasifier because most other feedstocks do not burn like wood, which is what the wood gasifier is set up to consume. Air flow, chamber size, reduction zone---wood gasifiers are set up for wood or woody feed stock only. Throw something non-woody in there and it all falls apart.

Using the rocket stove's heat to release and clean producer gas from a wide variety of feedstock might result in a true multi-fuel gasifier capable of turning landfill-destined trash or agricultural waste into fuel for engines and/or burners.

Bio-briquettes made from trash/waste could be burned in the rocket stove to provide heat to gasify a wide variety of feedstock in the gasifying chamber. Bio-briquettes could even be gasified in the chamber as well.

We need 1400 degrees to crack the tar molecules in producer gas, so it's clean enough to fuel an engine. A rocket stove can attain 1600 degrees in the flue. Seems to me there is potential to use that heat to generate clean producer gas from waste simply and economically. I say simply because the only skill required is the ability to operate a rocket stove. Wood gasifiers take more skill to run than operating a rocket stove. I say cheaply because the design is inexpensive and the fuel is real cheap.

I want that Mr. Fusion, which Doc had on the Delorian at the end of Back To The Future. Maybe this will work, maybe it won't. Either way, I bet we learn something new.

We need a longer burn time per load for the RS, a way to feed the gasification chamber with fresh feedstock, and a good reduction chamber design to clean the gas for this to have a chance to work. After that we need to add a filter & cooling radiator outside the RS, which will not bee too challenging because wood gasifiers already use them. If all that comes together, we might really have something helpful.

An inceneration plant explained their process, which I intend to adapt for the home user. They put trash in a large container. Beneath that container are natural gas burners. They use natural gas to heat the trash. Dirty producer gas results. That gas is piped to a second heat chamber, where the 1400 degree temperature cracks the tar molecules. Clean producer gas results. That clean producer gas is then piped to the burners beneath the trash container. The natural gas is shut off. Producer gas then continues to feed the burners to cook the trash until it is incinerated. In essence, this company figured out how to make the trash incinerate itself with its own producer gas, which is less expensive than using natural gas to incinerate all of it.

I want to do the same thing with a rocket stove. Heat the trash in the chamber, pipe the dirty producer gas to a reduction chamber inside the flue for high heat cleaning. Instead of feeding the clean producer gas to the fire, I want to pipe it to a generator so we can generate electricity.

The reduction chamber, where the gas is cleaned (tar molecules cracked) would be full of rocks hot enough to clean the gas. The gas would filter up through the rocks, coming out the top as clean producer gas. That's my first thought on the reduction chamber. Maybe someone here can design a better one.

So, to sum up, we have two chambers. Top chamber is heated and the feedstock inside offgasses. The dirty producer gas is piped to the second chamber down in the flue, where it gets cleaned with the high heat. Tar molecules are cracked, gas is clean. Pipe it out of the stove to a generator or storage bladder.

I don't care who accomplishes this first or who gets credit. All that matters is getting it done, coming up with DIY instructions, and spreading the information. If several of us try this and share our results, we'll get a solid working gasifier much sooner. I'll answer any questions to the best of my ability, especially if you are going to try to build one. If you know a member who might be interested in trying to build this, please alert him or her to this thread.

If the inceneration company can make this work, so can we. Thanks.

If this thing works, a person would be able to get the gas going and pipe it to the generator every few days to charge a home battery bank. If there were passive systems in place, like solar & wind, the time between runs could be extended.

These gasifiers could incinerate waste that would otherwise be going into a landfill. This will reduce the amount of methane released into the atmosphere as the waste decomposes. The rocket stove burns clean enough that it's a good tradeoff. The incineration process will provide producer gas to fuel a generator or even a vehicle, as well as heat water for home use.

The processes that happen inside a standard wood gasifier, which get complicated, are all about getting enough heat for clean producer gas without actually igniting it. Heat from a rocket stove would bypass those processes by directly heating the gas enough to crack the tar molecules. Simple to operatreek expensive to build from repurposed items, free fuel, free water heating, and environmentally better than allowing the waste to decompose and offgas methane into the atmosphere.
What's not to like about this setup, other than we can't know if it works at the home user level until we try it?

Bill, do you have a design yet or are you still in the concept stage?

Funny you should ask, Joe. We just ran our rocket stove for the first time about 5 hours ago. (we finished building it today, then just had to take it for a quick test drive) It got hot, really really hot. LOL. We did make dirty producer gas from a canister atop the stove and it did burn. Lots of tar, as expected. It was still pretty darn cool to do it, though.
The canister just smoked for a couple of minutes and that smoke wouldn't ignite. Then, just when we were getting worried, viola, success! The smoke suddenly lit and the canister spewed a flame of its own.

This is just the first baby step. Our test stove is complete, the test gasification canister is also complete. We proved to ourselves that we can make producer gas using an external flame as the heat source, though we were fairly sure it would work. The next step is to route/pipe the gas down into the rocket stove to a reduction canister to see if we can crack all those tar molecules. We need 1400 degrees F to accomplish this. Our cannister will be filled with firebrick pieces from smashed firebricks. The gas will enter the canister from the bottom, filter up through the brick pieces, then exit through a pipe at the top of the canister and out the side of the rocket stove.

This canister will be in the flames, so we're hoping the brick pieces get hot enough to crack the tar molecules as they filter through. If we can get clean wood gas this way, we can proceed.

The next step after that will be to make a bigger canister at the top so we can put a greater quantity of gasifyable material in. We're already designing a bigger stove based on rocket stove technology. We're hoping to build one that can be loaded with enough logs to burn for hours, rather than having to manually feed it every few minutes. (logs will be bio-briquettes made from pressed waste paper and agricultural waste, not wood)

After that, we'll be designing a way to add fresh material to the gasifier at the top without shutting down to reload. An auger & hopper will probably be used for this, though we're open to alternative suggestions.

Filtering and cooling will be done the same way it is on standard wood-only gasifiers. We intend to store the gas in innertubes, then run a generator from the stored gas. (I have access to lots of tubes) Since we have no air entering the gasifier the way a standard wood-only gasifier does, I'm not sure about the flow rate of the gas. Storing it first, then using it, solves that problem. I'll be curious to see if our gas has a high nitrogen content, since we're not pulling air into our gasifier. Does the nitrogen come from a reaction to the limited oxygen drawn into a wood-only gasifier, or does it come directly from the feedstock, oxygen having nothing to do with it? Don't know, but want to find out. Would be pretty cool to get a more energy-dense gas using this method, but that's just an idle curiosity of mine at this point. I just remember someone mentioning that the nitrogen content came from the air drawn into a gasifier to keep it hot and there was no way around that. We'll see.

A note of interest is that we had charcoal in our gasification chamber after it was done. We gasified wood this run, btw. We'll try other feedstocks once we get to briquetting.
I can briquette the charcoal, then burn it in the stove, using it as the external heat source for our next batch of producer gas. I wasn't expecting this byproduct, but I was hoping for it.

Please follow this thread and feel free to share it with others who might be interested. It's open source. By all means, if you want to do it too, go for it. I'll look forward to hearing whatever results you all get and assisting in any way I can.

I'm feeling pretty excited at this point. We're not there yet, but we're on our way down the path. This the most fun you can have with your clothes on, I'm telling you. Next weekend we'll be trying to clean the gas using the external heat source. I will be updating on our progress, or lack there of, as we continue on our quest for a simplified, truly multi-fuel gasifier. In the mean time, really think about what it will mean for independent, localized energy production if we succeed.

Take care, all. And thanks for taking the time to follow this.

Hey Bill, I will be following your experiment. I was lucky enough to work on an industrial sized wood gasification project about 5 years ago. We used wood chips fed with an auger into a gas fired chamber. as the gas and ash exited it was quenched in a water bath and compressed. We then made ethanol with it. We found that we had to get a lot hotter than 1400 degrees to crack the tar and spent a lot of time cleaning tar out of the system before we realized this.

The company built a full sized plant in Georgia and has since gone out of business.

Wonder if it was your companie's diagram I studied in preparation for this project. Now, that would be funny.

Wyomiles, my partner and I would very much like it if you made yourself available to advise us from time to time. You have done on a large scale what we're trying to do for home scale power, so your thoughts are invaluable to us. Nothing too taxing, just advice and maybe a few suggestions to kick us in the right direction, if you wouldn't mind.

And you said you made ethanol from a byproduct of gasification, as in vehicle fuel??? I'd be getting way ahead of myself if I asked you how you did that now, before we even know if this type of gasification works at the home level. Rest assured that if we're successful, we're going to want to know more about this.
You see, the biggest argument I see against fuel alcohol is that patrolium fuel is frequently used to distill it. I believe homemade methane or producer gas would make a dandy distilling fuel. Use non-food material to make the mash and we'd really be in business. Electricity AND vehicle fuel from this process would really be---too cool to let myself think about it at this early stage.

So, it looks like we may need more heat than I originally thought to crack that tar. I have to go with Wyomiles hands-on experience over a companies diagram of how it should work.
We have charcoal as a byproduct of this thpe of gasification. Do you think we could burn the charcoal in the stove to get enough heat to crack those tar molecules into short chain fuel? Or, if we put the charcoal in the reducer chamber, heated from the stove, and filtered the producer gas through the charcoal pieces, would that be a better way to clean the tar out of it?

If you absolutely positively had to get this type of gasification to work in a small home system, what would you try?

I'm a bit late to the party as I've really just started exploring a lot of the topics you have on the site. I suppose late is still better than never.
In any case, some clarification would be useful.

I've seen a number of videos that imply that a blue flame (no oranges/reds/yellows) from the gas output indicates no (or minimal) tars and other contaminants - I wonder if you can confirm that?

Does the breaking down of the tars (as opposed to filtering them) result in a useful byproduct (that would be good), or are they simply burned out of the gas and turned into heat?

I wonder about the benefit of Burning a separate fuel supply from that which is being gasified - at what point do you get more gas from the alternate biomass that you would have gotten from the original fuel? If you don't reach that point I'm not sure what your gaining.

I suppose you could use the waste heat form the rocket stove to dry additional fuels that might improve the initial gasification stage.

I suppose as a late state enhancement you could use a Stirling engine run on the rocket stove waste heat to turn the auger for the feed system.

Hi, Vince.

To the best of my knowledge, cracking the long chain tar molecules into short chain molecules results in more fuel in the gas. Someone with more knowledge feel free to correct me if I'm wrong, please. There's not much literature I came across directly stating that as a fact, but I think that's the case.

With the concern about burning more overall material, I fully expect it to burn more, not less, though with the charcoal byproduct that equation might change.
This gasifier is being designed with the intention of using trash that would otherwise go into landfills, so the more we burn cleanly, the better. We'll briquette the trash, gasify it, and hopefully, briquette the resulting charcoal and use it to fuel the rocket stove on the next run.

As for filtering it through a barrel of sawdust, the initial concern was polluted sawdust and what to do with it. With the rocket stove able to burn it cleanly, I'd be inclined to briquette the tarry sawdust and burn it during the next run. So long as the rocket stove can burn it cleanly, it should work. Thanks for making me think about that. If I can't crack enough tar out of the gas, that may still be a workable option. Maybe the tar will make the sawdust briquettes burn hotter in the stove.

As for the Stirling to power the auger, I think that's a great idea. I've got a Stirling design in mind to try out, so maybe we'll use it for that if we're successful with it.

We intend to us te rocket stove for water and home heating as well, so that should help the overall efficiency, if efficiency is a concern when burning waste to keep it out of landfills.

This project is still at an early stage. I don't know if it's going to work or not, but I'm going to try every last thing I can think of to get a successful multi-fuel gasifier. That way, whatever biomass resources you have available in your particular area, you can turn it into energy.

I will post our initial results on trying to clean the gas after we do it this Sunday. We'll try it without charcoal first, then with charcoal as the rocket stove's heat source. A good way to check the tar content of the gas is to run the gas trough a white towel and look at the towel to see if a lot of residue is on it. Checking the flame is another standard method. Yellow flames are not good. Blue flames indicate clean gas. We'll see.

Bill, the company was Kergi and then Range Fuels. I am not sure how much I can say because I signed non disclosure forms. Not sure how that works since they went out of business. But if you look at some of these patents you will find all of the theory that we put into practice. Some of which turned out to be wrong, as with the temperatures. The pilot plants and the full scale plant have been purchased and the tech is being tried by other companies so we will see if they can make it work.

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=0&p=1&f=S&l=50&Query=Klepper&d=PTXT

Wyomiles, don't get yourself into trouble. Advise us in whatever way you feel comfortable with.
Do nondisclose agreements cover hints? "Getting warmer, guys." "No, no, if you get any colder you'll make ice shiver.".

Already, your comments have helped us. We have a better idea of what we're up against with cracking tar. That charcoal byproduct might just prove to be vital to this project's success. I'm looking into home forges that use charcoal right now to figure out how to get as much heat for tar cracking as possible.

Our fallback position if we fail to crack the tar enough to run an engine without damaging it looks to be filtering the gas trough sawdust, then briquetting the tarry sawdust to fuel the rocket stove during a later run. It's not our preference, but it will allow us to gasify feedstocks other than wood, which is the main goal. We will still use the charcoal to ensure we burn hot enough to eliminate any smoke in the rocket stove, so we don't pollute the air with our tar waste.

We plan to throw together a sawdust filter so we can at least get some clean producer gas to play with. We'll catch some in an innertube, then test it for purity. That way, we'll at least be able to say we can get clean gas for running a motor.

Other than that, I'm not sure what else we can prepare for this coming weekend's attempt at cleaning up the gas with heat.

I want to thank those who have taken the time to comment. If we do succeed, we'll do so quicker due in part to you folks who brought up things we needed to expect and prepare for. Thank you.
Stay tuned.

FYI, Marcos has a topic 'charcoal gasification' that can effectively accomplish my goal of multi-fuel gasification. You should look it up as it has serious potential. I did comment on it because I'm extremely interested.

Quick update. My partner jumped the gun and built a reduction chamber. He tested it yesterday and said he got clean gas for a short while. He reconfigured it, trying for even better performance, and then got a lot of tar, according to what he told me. He's putting it back the way it was for this weekend's testing.
I was not there for this because I was grinding away at my stupid job, (I'm not jealous he got to play and I didn't ) so I can't absolutely back up his results, but I do trust him.

He also thinks he found a way to supply a rocket stove with enough fuel to last for hours, so I'm excited to get there on Sunday and see it all for myself.

We're going to have to work with charcoal gasification next. Really itching to play with that, too, but I have to keep to one thing at a time. At this point, I have no doubt we're going to succeed, one way or another.

hey bill, have you gave this thread a look yet? https://permies.com/t/4860/wood-burning-stoves/idea-invention-combining-stoves

pictures help alot sometimes, even if it is just an idea, maybe that thing with the crushed brick pieces in it you made...might be interesting to see!

As for your friend, the fire tender, have you-all thought of running a tube of syngas to the inlet of a normal air compressor & tank? I haven't tried it yet because the syngas might ignite within the compressor due to heat of compression, but perhaps low pressure (25 psi), and a large volume tank (50 gal.) might hold a good amount of syngas, safely.

Is you main goal to collect & safely store filtered/viable syngas, without a lot of air pollution creating it?

james beam

Hi, James.
Our goal is to build a clean burning gasifier that can gasify more than just wood. We want to put the producers gas to burners and motors for electric generation. We also want to accomplish home heating and water heating with it. We intend this to be the active part of a larger system that has passive power production from wind and solar. Heating will most likely be done by heating thermatic oil, than piping it to where heat is needed.

Charcoal is a byproduct of this gasification process. Our intended feedstock is municipal and agricultural waste, pressed into bio-briquettes. The briquettes that get gasified will become charcoal. The resulting charcoal will probably be mixed into the bio-briquettes which will be burned in the rocket stove on the next run, to get more heat for cleaning the tar out of the gas.

That's where we're at right now. We're at an early stage, so things might change.

Looks to me like your drawing will work to make bio-char. If you pipe the "smoke" from the char chamber back down into the fire below, that will both clean up the smoke so it doesn't dirty the air so much and it will feed the fire, increasing the heat and reducing the amount of wood you need to burn to make the bio-char, in theory.

You can add TEG's for electricity, but you will need to cool the other side. With your long winters, you can circulate antifreeze in from a barrel outside in a closed loop to accomplish that.

A portion of your charcoal might also be used in a charcoal gasifier to run a generator if you need more electricity.

I had thought I would like to store the producer gas in pressurized tanks, but members here helped me to see that's not really viable, though it is posible.I will store it in a stack of innertubes just to have some ready to roll without having to start the gasifier, but I won't be bothering to try storing it in tanks.

Last Sunday's stove test revealed another way NOT to set up a stove. LOL.
We're pulling air into the stove from the top, so the incoming air heats up before it makes it down to feed the fire. That part seems to work okay.
We tried to "swirl" the fire for a cyclone effect. Inside the flue, we placed a butterfly piece that was supposed to get the updraft swirling. It did swirl it, but it restricted the updraft too much and it didn't burn hot.
Also, we removed the sand so we could pull air down by the outside of the flue. I know, big mistake. We killed the best part of a rocket stove with that move.

Now, none of those mistakes is unfixable. We're installing pipes down the outside of the flue to bring in preheated air. We'll try to set the inlet nozzles so they swirl the new air into the burn chamber. We will also replace the sand once the air inlet pipes are installed, so the sand is all around those pipes on the outside of the flue. Hopefully, the hot sand will heat the pipes, also heating the incoming air.
For the fuel feed, we we're going to try not bringing in air through a hole in the briquette. The air should come preheated from the pipes in the sand. This should allow us to fill the feed tube solid with material.
One method we're considering for long burn times between refueling is a spring-loaded "log" in the feedtube. A stopper would stop the log from going into the stove more than an inch or two. When that portion has turned to ash, the spring should push more of the log in, which will be held at the stopper. The ash would crumble as more of the log is pushed into place.
The other method for consideration is making the briquettes into balls. The feedtube would be inclined at the back, so the balls can roll into the stove. The whole track would be loaded. A stopper would stop the balls from rolling all the way into the stove. When the burning ball has turned to ash, the next ball should roll in, keeping the fire going until the last ball makes it in and burns to ash. The longer the track, the more balls loaded, the longer the burn time between refills.

Has anyone seen others attempt either of these refueling techniques? If so, did they work or fail? Any comments or suggestions appreciated. We're trying to get as hot as possible in the stove so we can crack the tar molecules in the producer gas, so the gas becomes clean enough to run an engine without doing damage.

I'd like to be able to report that we got the stove as hot as humanly possible, a feat that impressed the greatest minds of our time, but we didn't even come close. It feels like we took a step backwards in one way because the stove didn't work as well as it did before. In another sense, I feel like we learned alot and will be able to incorperate a few new things into our stove this week.

If need be, we can scrap the air inlet tubes and put the air intake back at the feed logs or balls. We're just trying to bring preheated air in under the fire and swirl it for a cyclone effect. Next weeks test may not go much better than last weeks test. But, we do learn something each time we play and we're getting more familiar with the stove. All this should lead to a good attempt to getting the heat necessary to clean up the producer gas before it leaves the stove.

Tune in next week. Same bat time, same bat channel.

Last Sunday's test run went much better. We've got the incoming air preheated, the flue insulated, and the air swirling.
The air is taken in beneath the fire.

I think we've gotten it up to heat pretty well and have most of the final design complete. It doesn't look like any single stove we've seen. We incorporated things from several other stoves.

We're going to see what the gas looks like next weekend. Hopefully, we'll get some fairly clean gas. We plan to filter and cool the gas, regardless of how clean we get it before it comes out of the stove. The filter material will be briquetted and fed to the stove whenever it needs to be changed.

At this point, we know gasification is going to work, either as originally planned or by making charcoal for a charcoal gasifier. Our next step after this is to begin adding cost effective passive energy production. Solar hot water heating seems the simple enough, so we'll tackle that next. (Simple in that it's been successfully done and there are plans all over the place. We don't have to start from scratch)
After that, we will be working to set up wind machines that work at ground or roof level and that are simple and cheap to build.
We're both looking at battery banks for our homes now.

We got sidetracked with the Ecklin/Brown generator, so no further progress on the rocket stove gasifier this week. We're looking for a way to generate electricity from the stove that doesn't involve gasification and decided to play with this configuration. It works, but is not outputting as well as we had hoped. Our coils are all wrong and the magnets aren't very powerful, so it's no surprise the output isn't much. Mainly, we wanted to confirm for ourselves we would really get electricity from the setup, which we did. We're going to try a few other Lentzless setups as well before we get back to the rocket stove gasifier. I'm excited to try a magnetic piston that will run by shielding stationary magnets from a magnet inside a tube, which is wrapped with a coil. Works like a shake flashlight, only the stationary magnets on each end will be "turned" on and off in series with 2 blades to get the center magnet shooting back and forth inside the coil. Yes, we'll need rotation to accomplish this. But, a Stirling motor might have the speed and necessary HP to accomplish that. In theory, it should work. In practice, we'll get to see for ourselves.

In any case, that's where we're at right now. No matter which way we go, the rocket stove will be the heart of the active portion of our larger system.

I am also interested in wood gas. Our new dragon heaters seem to get hotter than a traditional rocket heater, This might help with higher temps. If there is some way we can collaborate that would be great!

So I've been doing tons of research, and I think there's lots of information about gasifiers that can benefit rocket stove development.

There is a bit of existing work on scaling gasifier stoves down really small. For example: http://www.hedon.info/docs/BP53-Anderson-14.pdf

The riskier part about these is that I am uncomfortable with using them indoors. CO is a normal part of gasifier operation, and if the "secondary" burn doesn't get enough air or for some reason goes out, I wouldn't want that leaking into living space. But if the goal is to run a generator, they can be run outdoors or in a well ventilated area. You'll just have to deal with the heat loss to the out-of-doors and some mechanism for capturing and safely transferring the heat indoors.

For the water heating inclined: http://www.chipenergy.com/brochureflashboiler.htm

and there's a veritable ton of information, formulas, sizing charts, and even a "gasifier experimenters kit" here: http://www.gekgasifier.com/

Sandy, we will freely share our design for the stove. It's our goal to put the info out for anyone who wants to replicate. We might build them or supply a few of the more difficult parts to make at a profit, but any customers will have access to the same plans everyone else has, so they'll buy only if they don't want to build it themselves.

That Chip Energy furnace looks great. Thanks for the link.

At this stage we're fairly confident we have the heat necessary to gasify just about any gasifyable material. We've generated what we think is clean producer gas already (tested with a white cloth, not anything more elaborate) on a small scale, which is why we're confident. Gasifying plastic is a goal of ours as well and we'll try once we've made one last configuration to the furnace. We're setting up a burn chamber beneath the flue. Our last test made the flue glow red hot when we ran it wide open for 10 minutes. It smoked for less than 30 seconds upon start up, which I think is pretty good. The outer wall was too hot to touch within a few minutes. (flue is insulated like a normal rocket stove)
My partner gets credit for the stove as it is his design. He incorperated a lot of things we saw in other stoves to a point where this thing no longer looks strictly like a rocket stove. It works much better (burns way hotter) than the original rocket stove we built. It's taking in preheated air and swirling it up the flue. The air intake is adjustable, so we dont have to run it full throttle all the time. We've got an automatic feed on it so it can go longer between refueling. All in all, I'm very happy with our progress so far. We're hoping others might find value in its use.

The last model we build will be smaller, but will improve upon our latest performance. After we complete that one, we'll be ready to build a better gasifier for it. We want to be able to manually feed the gasifier while it operates. The feedstock will be garbage, to begin with. That feedstock should not need much processing. We're hoping to compact it and feed it into the chamber. Like I said, we want to try plastic as that should be a fairly energy dense material. We will have a filter, so we'll get to see if the plastic fumes leave a paraffin residue or if the furnace cleans that up as well. The sawdust in the filter will be made into bio-briquettes and fed into the furnace if we gunk it up, which should dispose of it cleanly.

The other thing we intend to use this stove for is heating thermatic oil, which will circulate to a radiator in the ductwork. We're hoping to flip the furnace fan on to distribute the heat to our homes. Hot water will also be provided from the stove. That will be tackled/attempted after the gasifier is up and going.

For my house, this stove will run outside. For my partner's house, he wants to install it inside. I'm curious to see how he plans to make that work. After seeing what he's accomplished so far, I'm not going to doubt he'll make that work.

Another thing he wants to attempt is to install a turbine on it. I'm not exactly sure what he has in mind, so it should be interesting and I'm sure I'll learn something new.

And, you can cook on it as well if you cut the air intake back. We want to play with water distilling and desalination as well, but later. We've made a lot of progress so far, I think, but there is still a long way to go. We need to tackle air conditioning, the Ecklin generators, wind turbines that operate at roof level, and solar heating, to name a few. I'm going to get to play for many years to come, I think.

Everyone who has posted/Bookmarked/set a watch on This Thread - should/should have checked out Rob Torcellini's Thread 'Burning Pellets in a Rocket Mass Heater'
there his Videos show the continuous feed he users with his 'Rocket Stove' to heat his greenhouse/Aquaponics system !

[ Please note that this thread has grown to two 2 pages, videos you want to watch are on 2nd page !]

My contribution here is to suggest looking at large Autoclaves [ 30 gal-ish and some bigger ] .These have plumbing that should be super adaptable for a
Gasifier Chamber !

Be safe,keep warm ! Pyro Magially Big Al

Thanks, Allen. I'll go look it up. Glad so many others are building these types of energy gadgets. If we all keep at this, people will have better and better options to power their lives other than paying the energy providers.

allen lumley wrote:
[I] suggest looking at large Autoclaves [ 30 gal-ish and some bigger ] .These have plumbing that should be super adaptable for a
Gasifier Chamber !

Steam autoclaves seem to be designed for 132C. that's way too low. I'd be afraid it'll melt.

Any Pictures you can show us yet Bill?

Kevin W.: Mea culpa !!! Re-reading over what I wrote shows the need for me to clear up a few things. Perhaps if I had started with a descirption of the chamber that holds a load of wood while it is being 'Kiln Dried', and then spoke about the plumbing arrangement of a working Autoclave as an adjunct to a gasifying chamber, then my thoughts might have been more clearly expressed.

I am making a very small point that when a successful SAFE gasifier is made it will have many of the characteristics of an Early Autoclave. My hope was that we might save some time by not trying to re-invent the wheel !

- After years of people being maimed and even killed by Autoclaves, the 130 c temp was found to be the lowest temp that could create medical sterilization . A violent autoclave failure was even used as a 'back story' in 2 separate "Mash" series episodes !

Today - most Medical Autoclaves have been downsized to a capacity of only about 5 gal worth of space - or much less ! ! I was referring to the work that has been done in creating a workable plumbing arrangement, especially good seals - necessary here to keep oxygen out of the containment vessel as the only way to keep the reducing biomass from consuming itself and/or the 'producer,or syn gas '.

I could have referred to Grandmothers pressure cooker or to its descendent, a pressurized system used to spray paint,or 'white wash ', the fact that todays more modern systems can be operated safely by an untrained person, still allows us to look at what is/was out there, and its operating characteristics . Again let me apologize and say, that I was only 'spitballing' an idea - If I am going to put my thoughts out there it is MY duty to read over the material to make sure my thoughts are clearly expressed !
.
. Be Safe, Keep Warm, Pyro magically Big Al

Hey Bill- I'm also interested in gasification and biochar. currently working on getting a Adams retort to work at top efficency, but also just finished a rocket stove. Keep us posted on your project and any pic or unit layout to share?
Steve

No worries, Alan. Any ideas that could help are welcome.

We have pictures and videos. Just need to get them up here, or links to them. My partner is not exactly verbose, so a few videos are more like silent films. Lol. But, it does show it operating.

We're building another one from scratch. After that we'll be working on the gasifier portion of this. We need a more durable, modular setup for gasification. We want to use the stove for more than just gasification, so we're building modular pieces to put on/in it. In the end, we want to be able to cook on it, heat water for the home, heat thermatic oil for home heat, purify water, and gasify just about any gasifiable material. Those are the goals, at any rate.

We haven't taken the rocket gasifier any further at this point. We believe we have the necessary heat to achieve clean producer gas from just about any gasifyable material, but we need to actually test that with something better than a white cloth and looking to see the blue flame. We're going to have to run an engine for an extended period of time, then tear it down to check for tar build up or damage.

Right now, we're working on the Lenzless generator. My partner is busy with work and so am I, so we're working seperately until we can get back to this. I'll post about the generator soon. We're adding linear generators to the Ecklin setup. If we're correct, the output should be dramatically increased while the input remains the same. It's a simple addition that operates from the same inductors that are already on the Ecklin setup. Lenz's Law is still very much in evidence, but should have little effect on the spinning inductors---on the energy input to spin the inductors.

This is the generator we hope to attach to the producer gas fueled motor, or stirling, or windmill, or hydro unit. I don't know if it will run itself, and neither does anyone else. I can't find any work being done with this particular setup, though there is plenty of examples of Lenzless generators and linear generators powered by free piston engines. What we're doing is a bit different than those, though we're using a lot of the same technology.

I believe we have something worth building and sharing here. We'll see.

My partner is gathering the materials to build a more user-friendly, smaller rocket stove gasifier. He'll be using thicker SS to make the flu. The flu got extremely hot on the big stove he built the last time we ran it full blast. We got worried when the inside flu glowed bright red. We didn't try charcoal in it, though we know it would have burned hotter. Next one should stand up to the heat better, I think. Also, all intake air will be brought in from below the fire in the next one. Our current model brought air in from beneath the fire as well, but also from the fuel feed tube. We want the ability to control the air feed, which will control the heat, so we'll be adding a sliding "door" to the air intake.

We will be adding a spring-loaded slide to feed the fire. Bioblocks will be inserted into the feed tube. The spring will push them into the fire a bit at a time. This will give us the ability to load enough blocks to run the fire for an hour or so between refueling, depending on how the air intake is set. Fuel feed tube will be fully enclosed.

The gasifier will be more streamlined as well, though it doesn't need much of an overhaul. We're extremely happy with its performance. We'll be adding a feed system so we can add material to gasify while it's operating, instead of waiting until its shut down. Also, we're looking into a catalyst that is supposed to help convert moisture into hydrogen. We don't know if this will work, but if it does, we would like to be able to gasify material with a higher moisture content and get a more energy dense motor fuel.

We're learning as we go.

This is one of the most exciting threads of come across on here yet. I can't wait to see the plans...keep up the good work!

So, we've got one heck of a rocket stove. A problem we're having is consistency of the quality of the gas. Yes, the stove does get hot enough to clean the gas, but only when it's running wide open and eating up fuel very quickly. If we slow it down, it doesn't run at its maximum heat, which we need if we're to clean up the producer gas enough to run an engine, consistently throughout an entire run.

Still, even if the rocket stove can't reliably burn hot enough to clean producer gas without going through way too much material, this was not a waste of time. A rocket stove like we built has other uses and it is still the heart of our energy system. We will still be using it to heat our homes and hot water. And, the feed system itself was worth accomplishing. The ability to run it quite a while without having to constantly push sticks farther into it is an advance that makes running one less user intensive. We're also sure we can use it to make charcoal without polluting the air, which is useful for the next step in our quest for a multi-fuel, gasify-anything gasifyable, gasifier.

We learned a ton and will be releasing info for any folks who want to DIY this rocket stove for themselves.

Nor have I given up on a multifuel gasifier. We're moving straight to charcoal gasification. We'll be trying to build a separate, reloadable chamber inside the charcoal gasifier. It's in that chamber, surrounded by hot charcoal, we plan to put gasifyable materials other than wood. The theory is that the dirty producer gas will filter out into the bottom of the hot charcoal bed and rise up through it to the top, after which it will exit the charcoal gasifier, along with producer gas from the charcoal itself. The heat from the charcoal should cause the material in the chamber to off gas. We'll see if the hot charcoal is hot enough to crack the tar molecules for a quality gas capable of running an engine. We'll be attempting wood first to see if the producer gas comes out clean or not. If it does, we'll try plastics and other waste materials.

After that we'll either have a gasifier that can gasify many different materials or we'll be able to eliminate one more unworkable idea from our list, bringing us one step closer to that thing that will work.

Gasifying plastic is desirable to us because too much of it never really gets recycled, it is extremely inexpensive, and it is supposed to be energy dense. If we can gasify it cleanly (without polluting the air) and get quality producer gas, we'll have accomplished something useful. (We'll be using plastic from milk jugs and soda bottles, never PVC.)

Another area to explore is making charcoal from sources other than wood. There's a project in Kenya right now that is doing just that. I don't know if their charcoal made from waste is suitable for a charcoal gasifier, but I intend to find out. Bio-briquetting will probably play a big part of this, I think.

I'll report our results whether they succeed or fail.

We attempted the charcoal cleaning of the gas today. Feel like a real dipwad. The charcoal was damp and wouldn't burn well. We also used small holes to allow gas from cut up plastic bottles into charcoal chamber. Big mistake there, too. Every hole clogged with parrifin residue.
Will make a fresh batch of charcoal tomorrow and use bigger pipes for the inlet.
Note to self: Half-assed preparation gives half-assed results. We'll try doing this the right way tomorrow.

Bill B. : Have you watched the (3) Gary Gilmore - Gasifying charcoal Videos on You Tube ? I just watched them and discovered large ASSumptions in my thinking !
He uses a worm gear to add Hydrogen rich fuels to his controlled Charcoal gassifying burn after he has started his generator on the Carbon Monoxide Rich smoke from
the initial Gasifier burn !

I am trying to find a link to a simpler process for converting Plastic back to Petroleum! I know I pointed out that link to someone, just need to figure out Who !

For the Crafts ! Be safe, warm ! As always, your questions/comments are solicited and Welcome ! PYRO-LOGICALLY Big Al !

Bill B : Turning plastics back into petroleum is apparently even easier than we thought! Check out Vimeo.com 4139407 , this is Originally work from U.N. University
Channels. I guess that the plastics labeled 1 inside the recycle triangle is the one you should not try to reprocess ?

For the Crafts ! Be safe and warm ! As always Questions/comments are solicited and Welcome ! PYRO AL

Thanks Allen. I've been watching Gary's videos, since he's on the leading edge of charcoal gasification. I'm glad to hear he's adding steam reformation to his unit. I'll have to check that out to see what he's using as his catalyst. If my info is correct, the catalyst should have a high Nickel content.

http://www.trumpetcalling.org/gasproducer/

That link is to an account of driving across Australia on producer gas. Well worth reading. He apparently used materials other than wood in his charcoal gasifier, like tire treads. Multi-fuel? Was he running the producer gas through hot charcoal to ensure clean, non-tarry producer gas?
He also set up automated cooling via steam from a water jacket on his gasifier. The introduction of hydrogen greatly increased HP in his vehicle and miles per pound of wood, according to this account.

Reading this gave me hope that I'm on the right track about a multifuel gasifier that not only accepts damp feedstock, but uses the extra moisture to increase the hydrogen content in the gas.

Thanks for the heads up about plastic soda bottles. That is exactly what we tried to gasify without any success. LOL. We'll attempt milk jugs instead, since I know those will off gas burnable fuel.

Quick question for anyone who can help: how much incoming air, if any, does the charcoal need in order to burn, after getting it going and closing the top? With raw producer gas filtering up through the charcoal, we can't let in enough air to ignite it.

Hi everyone. A very interested topic and something I've been looking at myself for a while and can maybe contribute a few thoughts. I've only quickly scanned this thread, so apologies if some of these points have been covered.

This concept for gasification has been around for awhile i.e. separating the producer gas feedstock from the heat source. I first came across it while doing my Chem Eng degree 20+ years ago. In terms of terminology, Bill is correct to call this 'producer gas' as 'syngas' is produced using pure oxygen for combustion. Producer gas (or wood gas) is produced using air, and will contain a lot of inert nitrogen, as compared to syngas. Sorry to be pedantic but that may help people when it comes to searching for production ideas.

The blue flame mentioned is the combustion of carbon monoxide with hydrogen and water vapour (yes, water vapour is an important component of the reaction sequence) and yes it does indicate good combustion.

Cracking the tar should be done in the presence of a catalyst - the type used will determine which reactions are favoured and I wont go into all the options here, but iron is I believe the most common for poorer feedstocks such as biomass. This can be as simple as an iron pipe, perhaps with iron filings inside if you want to get more complex.

A point to consider though when working with this gas is that you will get different producer gas components depending on the type of feedstock, the type of materials used to pipe the gas, the temperature of the heat source, the moisture content etc.

If you're thinking about gas to liquid conversion then you're talking about the Fisher-Tropsch process. This process is generally done at below 300 deg C. Higher temps will generally favour methane (which of course is not a problem if you want methane), but of course methane is harder to store if that's your aim, than something that can be easily liquefied.

I mentioned water vapour above. You should keep this in mind when thinking about feedstocks - using plastics for example will probably need an additional source of water.

Some useful documents for those who want to get deeper into the topic while still keeping it relatively simple are listed below. Though they all describe a traditional type of gasifier, they all contain relevant info for this type of project:

Handbook of Biomass Downdraft Gasifier Engine Systems, Solar Energy Research Institute, US Dept. of Energy, 1988 (some good info of tar cracking and fuels)
Woodgas as a Fuel Engine, Food and Agriculture Organization of the UN, Paper 72
Construction of a Simplified Wood Gas Generator for Fueling Internal Combustion Engines in a Petroleum Emergency, FEMA. 1989 (2nd Ed)

There is an interesting video here ... http://www.youtube.com/channel/UCVP1PTBbRGpmTQE1oQx8xNw (the Teslonian Man Show) which shows a practical 'backyard' application of what this thread discusses. It doesn't use a rocket stove heat source but he does separate the feedstock from heat source and goes as far as tar cracking and running a generator from the resulting hydrogen once all the hydrocarbons are stripped out.

Hi, Craig. Thanks for posting. Thanks for the heads up on the iron catalyst and hydrogen content. I just found out about Mr. Teslonian (sp?) the other day. He's ahead of me on this, for sure. That guy is making liquid engine fuel in his back yard, for crying out loud.

My goal is to make producer gas clean enough to run an engine from any gasifyable feedstock, not limited to wood only. Yes, I'd like to dispose of things like dog/human poop, trash, plastics, waste paper, and plant matter while turning it into energy.

If I understood correctly, we need to pipe the gas from the top chamber, with appropriate steam content, through a lead pipe down into the stove. Put lead filings and nickel filings in the reduction chamber, which is down at the hottest point inside the stove.
Pipe gas out of reduction chamber and to an ole fashion sawdust filter, then through a radiator to cool it, then into the engine.
Sawdust from the filter gets compressed into pellets or bio-briquettes when it needs to be replaced. Pellets or briquettes are fed to the stove at a later point both to dispose of it cleanly and to fuel the stove.

We very nearly melted the flue the last time we ran it wide open for 30 minutes straight. We've since built a more sturdy version to handle that heat, so no more fears there. We should be able to run charcoaled biomass for an even hotter burn without damaging it.

Our new stove is more compact, made of thicker metal, and modular, which means add-ons will snap into place. Add-ons we are working on include the gasifier, cooktop with oven, water heater, and thermatic oil heater for heating a home or RV or tent. Future add-ons we're looking into include a TEG setup for quiet electric generation, water distiller/desalinater, and possibly a boiler to run a Tesla Turbine, if that can be done safely. Additionally, we're experimenting with our Lenzless generator in the hope to power it from the stove, since that's a low torque, high speed application. Who knows, maybe it can be made to snap right onto a RMH at some point, allowing it to be removed & used for other applications during the summer. We plan to take this stove to the limits of what it can accomplish.

I'm fairly excited to finish the final version of the stove that folks can use. It's small enough to be portable, but powerful enough for applications bigger than cooking. It'll be open sourced, so folks can build & use it, or go into business building it for others, which is exactly what we intend to do ASAP.

Thanks to all who participated in this thread. It's all leading to something good.

Yesterday, we built & tested the 3rd iteration of our stove. I showed up at 10:30AM and left at 9:00PM.

We've gone with a square configuration that is half the size of the original with a flue height at waist level. It is light enough to carry easily. The L pipe is inside the box & preheated air from dead air space inside the box is swirled around and into the fire to feed it. It does not draw outside air from the end of the tube, like a standard rocket stove. Air is brought into the lower box trough the back, below the flue.
The second change was a second air intake at the vertical flue. Air is drawn into the vertical box, then drawn into the flue holes a foot and a half above those intake holes on the outside of the box. This air is also preheated and creates a reburn in the flue.
For this trial run, there was no insulation at all in the stove. We needed to see how both air intakes worked without it.
The results were better than we expected, easily matching the last fully insulated version. It ran absolutely smokeless and came up to heat in under a minute. There was no smoke back at any point. We lit a single piece of paper in the cold stove and the smoke immediately drafted up the flue. Wide open, I was unable to hold my hand above the top, even standing on my tiptoes with my hand held as high as I could above the flue. The draft out the top feels like sticking your hand in a very hot, fast wind. (I believe the secondary air feed in the flue increases velocity quite a bit) Looking down the flue while lit can only be done safely with a mirror. No one under 9 feet tall will be leaning over to look down the flue without singing off their eyebrows.
All in all, we're very happy with performance. To finish out, we'll insulate, add adjustable feet so it sits level above uneven ground, and put the final choke on it so the air intake can be regulated for hotter or longer burns, depending on which add-on is snapped into place and how much heat it requires.

We're hoping that using this same stove for multiple purposes and tasks will ultimately make gasification, water/oil heating, cooking, charcoal making, waste disposal, and steam power cheaper and more user friendly. We'll see.

Oh, and it didn't eat up as much wood running wide open as our last stove. Again, I think the reburn section with its second air intake is responsible for this.

I think the performance of this stove soundly beats the standard rocket stove we first built and will prove to be more versatile and just as portable.

It's only going to perform better once we properly insulate it, so we're just about finished with our final iteration of the stove. We're working on the gasifier add-on as well. Hopefully, we'll successfully and reliably make clean producer gas from a variety of feedstock by the time we complete our final stove. We're also working on a 2 burner cooktop with an oven for baking, so we're hoping to begin with the stove & 2 add-ons. Sky's the limit after that.

https://www.dropbox.com/sc/kkcremo2vc202x6/OVPihVsQfW

My partner got on photobucket, so we'll start posting more pics and videos soon. In the mean time, here's 2 quick snaps of the stove.

I'm more confident than ever that we'll get a multi-fuel gasifier to work. While I believe we can now reliably get enough heat out of our last version of our stove to clean up the producer gas, I had to plan on failure and find a backup method to accomplish this goal, just in case. Researching led me to believe that the dirty producer gas could be cleaned up by running it through a seperate charcoal gasifier. I knew that in theory, it should work. But, there was nothing I could look to in past designs to confirm this, or at least give evidence it will work---until now.

Copied excerpt:

(Perth, Western Australia, 1981. A Toyota diesel Land Cruiser fitted with dual firebox gas producer being tested. The unit has both an updraft generator for charcoal fuel and a downdraft generator for wood chips. The two are coupled so that gas from the wood chips passes through the burning charcoal and is purified of tars before entering the engine. For short runs, only the charcoal generator is lit. It is efficient, quick starting, and handles variable loads with little change in gas quality. For long runs, both fireboxes are lit. The gas formed by the downdraft generator supplements that from the updraft generator. The downdraft generator has three rows of air inlets (tuyeres). By unplugging the different rows a wide array of fuels and horsepowers can be accommodated. The unit shown was sized for use on an 8-ton truck.)

What this means for the charcoal gasifier crowd, started by Gary Gilmore, is their gasifier is capable of cleaning up dirty producer gas. A down and dirty biomass gasifier that outputs tarry producer gas, but from a hugely wide array of feedstocks, can be coupled to his charcoal gasifier to produce a greater quantity of clean, engine-ready producer gas. What's more, if thoughtfully designed, this second gasifier could produce more charcoal as its byproduct, which would go into the charcoal gasifier during subsequent runs. Also, it should be possible to use the waste heat from the charcoal gasifier as the heat source to gasify the material in that other gasifier.

If the implications are thought through, this should be recognized as great news. Not only are the gasifiers good for energy production, but they'll also be great for the clean elimination of waste. The utility companies will be overjoyed to learn they could soon burn less coal to generate less electricity and the garbage companies will be relieved when 60%+ less trash goes to the curb.
(Kidding a bit, there. We all know that if this ever catches on, the govt will have to outlaw the technology in order to protect the energy companies and waste disposal companies that are "too big to fail." As well, we all know that 99% of the population is content to use coal and oil products for energy, right up to just before the coming energy crisis hits us all.)

I'm going to continue with my original attempt to use the stove only, no charcoal, to accomplish this. But, I'm going to fire off an email to Gary in the hopes he'll share this with the people following and working with his charcoal gasifier. We'll see what comes of it. Hopefully, they'll get this done on their side and before long there will be two different ways to accomplish the universal, turn-just-about-anything-into-energy gasifier.