FEMA Gasifier

One Straw is all about Being the Change you wish to see in the world. Most of my energy is focused on local, sustainable food production, but as it is written man cannot live on Bread Alone. So I was thrilled to have the opportunity to partner with some local folks in our Sustain Jefferson group during the Winter of 2007/8 to begin constructing a Stratified Downdraft Gasifier based on plans update by F.E.M.A. during the late 80’s The plans were found on Gengas (and are also located in the resource section in their entirety) and are intended to power a vehicle, usually a tractor, during an emergency fuel shortage -like if a Category 4 Hurricane hit the Gulf Coast and flooded a major metropolis. Not that that would ever happen…

The fact that the plans are designed for a crisis has some BIG upsides and some significant downsides. On the upside -the plans are intentional designed “loose” -you can build a FEMA gasifier from just about any scrap metal that even comes close to matching their plans which is fantastic if you and your community are freezing and hungry in a crisis: you can build one on a shoestring budget in relatively little time. The downside is that all that “looseness” in the deisgn means that alot of corners are cut and the design is not intended to operate for the long term, say sustained use in a Peak Oil or Energy Bioneer situation. More on those challanges in the more detailed pages and videos of this section of the blog.

Why am I excited about gasification? Several Reasons:

  • You don’t need a PhD in Engineering to build one -though welding skill is needed.
  • Its CHEAP. Even with a fancy copper heat exchanger, sourcing a used engine and generator we will come in at under 10% of a 15kw PV array.
  • The Fuel is local and renewable. Any softwood will work just fine.
  • Both Electricity and Heat are created, and captured, at once. Nice!
  • The same system can also pump water, chip wood, etc if the engine has a PTO or if you convert other engines to run on the syn-gas.
  • Super efficient burn means freaky low emissions and lots of run time: 10# of chips = 1 hour.
  • The end result is Bio-Char -a fantastic soil amendment that literally sequesters 50% of the carbon input to the system.

Our gasifier is designed to end up as a small Co-Gen unit supplying both electricity and heat to a residence using only sustainably harvested carbon from the community. While we have successfully built a gasifier, we still need to iron out some significant details like a sustainable filtering mechanism, efficient heat exchangers, and sourcing a 12-15kw generator.

The technology is proven -literally millions of gasifier were in use in WWII in Europe and Korea was running taxis on them well into the 80’s. What we need now is to use the updated, safer, and simpler FEMA design and tighten up the design to allow it to be used sustainably in a home, long term, with reasonable maintenance limits -hopefully no more than with a typical outside wood burner. But this wood burner uses a fraction of the fuel and emissions, and you get electricity to boot

Interested in learning more? Check out the these pages for more info:

Why Gasifiers Rock



Just remember that you incur any risks as your own should you attempt to create hydrogen for yourself!  Gasifiers, like all machines, are dangerous and must be treated with respect and all due caution

I will update the pages periodically with our progress and please drop comments with other resources you find out there. Wood Chip Gasification is incredibly exciting -and I love the grass roots nature of it!


13 Responses

    • Rob,

      I have looked at the shop-made gasifier shown on the Sustainability Jefferson website and am assuming that it is one and the same as yours. I have noticed a few areas that could possibly be improved, i.e., larger hopper, add an auger to the top of the rod to stop bridging/choking of the wood chips, etc.. If you could send me an email address where I could email you with an attachment… drawing of the changes I think would be beneficial… it would be greatly appreciated. My reason for this, is that I want someone with a more expert opinion than mine to review my suggested changes to keep me from making a gross mistake.

      Thanks for the way in which you are supplying information about useful and simple wood gasification devices.

      Noble Faubion

  1. Check this gentelman’s site out for an off the wall, elegant, but brilliant, idea for a gas scrubber.


  2. Great Link Owen! I am intrigued by the “bio filter” an love his homemade “chunker”. He is using a smaller BCS which is encouraging as I intend to use the Grillo as part of a similar system in the future.


  3. hey there fellow earthworker!

    i was very excited to find your site on wordpress, as i am a new wordpresser myself….solosoikos is my blog….it means one sun and many homes….

    i document the practices on our farm and retreat center…

    your page has really great design and information, i am interested in design projects that pertain to energy…sounds like the gasifier is one of these!

    thanks one straw!
    how do you plan on reducing tillage? large scale production on no til? how can we do it?

  4. Reducing tillage has many paths -the main one is in reducing the need for tillage: compacted soil and/or weeds. Mulches and covercrops help on both accounts by sinking roots deep into the soil, and smothering the surface blocking light.

    The other main hurdle to overcome is the Western “need” to till -our knee jerk reaction to take spade/tiller to the soil as soon as the crop is done.

    Read Masanobu Fukuoka’s One Straw Revolution to get a more philosophical view on the issue.

  5. Glad I stumbled upon your site! I too am working on a sub-acre market garden, going pro this year. Good bye to the grey cubicle and corporate world. I am also working on a gasifier project. Mine uses a Lister CS diesel clone and one of Jim Mason’s gasifier experimenter’s kits. Ready to run the engine this weekend I hope. Looking for chip sources….any ideas?

  6. We got our chips from our local municipalitiy’s chip pile, but after some issues with the chips “bridging” in the unit, we switched to wood pellets designed for stoves. If you want to make your own pellets check out a small pellet mill from http://www.pelletpros.com

    Good luck on your projects! The World needs more people Going Local!


    • I’m very new to this wood gas thing…been spending my time on passive solar and Vawts and haven’t caught the wood gas bug yet. Checking out a few web sites on the topic its easy to see how one could get caught up in this one. Regardless, I haven’t found any discussion forums on the topic other than this one, so let me pose a newbie question to you…if enough wood gas can be produced as in Ed Burtons version, could you not draw the gas through a compressor (instead of an engine) and store it in a propane tank. Then, could you not burn the gas in a modified propane fireplace or furnace? Are there any sites out there that comment on storing wood gas?…safe pressures and so on?

      • Wood gas is fantastic, but it has some issues that must be overcome. You have already found one, so you’re doing well! One of the primary combustibles in wood gas is hydrogen. Hydrogen is really REALLY small. So small that goes through just about everything, even stainless steel. Unless you had something ridiculous like glass lined lead tanks or something your gas begins degrading the instant you make it. You might be ok if you use it within a day, maybe not, depending on how finicky your engine is. The second problem is also exasperated by storage – wood gas is dirty as its contaminated with varying degrees of tar and other solids. This can be controlled to some degree by the quality of the burn and various filtering, but it adds complexity and must be designed around. Also, storing the gas concentrates the impurities. The best designs use the gas as its made, and any excess is flared off in a boiler (NG hot water heaters work great and are easy to convert) to be stored as hot water. If a generator is part of the system (recommended) excess gas can be stored as electricity in batteries.

        I see no reason that any propane appliance couldn’t be converted. We converted water heaters for boilers, and increased the gas inlet to about 1″ to offset the low pressure of the wood gas system. Worked well. Do this at your own risk and only after proper precautions – messing with combustible gases is inherently dangerous!

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