Watch Me Build My Own High Efficiency Wood Gasifier

Prototype Gasifier Build

Wood Gasification Prototype Build

Today I would like to announce that I plan on building and testing a high efficiency gasifier similar to Larry Dobson’s wood gasifier PLANS.  I plan on providing you with all the manufacturing details and REAL TEST RESULTS! I want to forge the path for all DiYers to build and demonstrate the usefulness of this product. 
Probably one of the best reasons is to run a generator for power! Just like in video below

If you do not know what a wood gasifier is or do not understand why you should own one please read my post  What is a Wood Gasifier and why you WANT own One!
Once I finish the testing phase, I plan on incorporating an automated control system that will ensure that gasifier always operates at the highest efficiencies possible.   This will be accomplished by using properly placed thermocouples to monitor the gasifier’s performance, and to provide feedback to the air damper/agitator’s controller.  This will help those who do not want to heat water, but would rather use the exhaust gases to power an internal combustion engine (such as a home generator!).  In order to run a generator you want the exhaust gas to be as clean as possible. 

Wood Gasification Operation Explained

The picture below shows the main activity zones within the gasifier.  The numbers Located in each zone correspond to the numbers in the table below.   Read through the chart while looking at the diagram so that you can gain a basic understanding of how the gasifier is setup. 

 Wood Gasifer Critical Zone diagram


Gasifier Air Flow Path:

      1.  Air comes into an open bottom duct shell, passing through a rotating damper, then radially outward, where it convects up along the hot inner combustion shell, with the highest air velocity occurring near the shells surface due to natural convection currents (most efficient heat transfer by far).  At the top, the heated air transfers outward into the hopper-heating duct, where some heat is removed from the hot air and transferred to the outer surface of the fuel, guaranteeing fuel ignition by the still quite hot gasification air, even when the inner fuel is wet.

     2.  There is where wood Gasification occurs.  This mean that the combustible gases are separated from the wood/ash byproduct.

     3.  This is where the fuel is added to the Fuel Hopper.

     4.   This is where the exhaust gases flow through the spiral heat exchanger heating up the water contained on the other side of the inner metal spiral.  If your not using the gasifier to heat water then this where the heat contained in the exhaust gases is used to heat up the cold outside air (from zone 1 to 2).  This greatly increases the efficiency of the gasifier because must of the heat used to vaporize any water in the fuel is reclaimed.  This is why Larry is able to reach such high efficiencies even while burning relatively (up to 50% water) wet fuel!!  This is a significant improvement over the imbert gasifier’s design.  Although untested,  I believe this gasifier will serve to free oneself from reliance on modern society by using a free, renewable energy source.

    5.   This is where either the producer gas or the combustion exhaust exits the gasifier.  If your using the gasifier to heat water in the spiral heat exchanger then at zone 5 you have the exhaust from the internal combustion in the ceramic shell.  Realize that which ever mode you use the gasifier in (water heating or fuel gas producing) it always produces fuel gas.  Larry has designed the ceramic shell to be a circumferential combustor which helps keep efficiency of the system high.  There is actually a controlled fire ring burning around the gasifier during water heating mode!

if you are running a generator you won’t open the second air inlet so no internal fire ring will ever start.  The gas exiting at zone 5 is now combustible (burnable!) so you would send this directly into your generator and your up and running!.  You could also use this clean burning gas for a stove or any place you would use propane.


Once you understand the function and importance of each zones look at figure 2 which flows the air as travels through the gasifier. 

Wood Gasifier Air Flow Diagram



Figure 3 shows the path of the water (which is to be heater) through the spiral heat exchanger.  *note you do not need to use this function of the gasifier if it isn’t needed.  If you want to use the exhaust gas for another purpose then you would simply close the secondary air damper and drain the water from the heat exchanger. 

Please visit Larry’s website to download the complete set of plans and drawings.  If you are interested in building one of these for yourself you should look over all of the construction and assembly documents.  If you have any questions please feel free to ask. 

IF you do not have all of the tools required to take on such a project check back early next week as i announce a smaller project that I plan of beginning immediately!  You definitely won’t want to miss out on this one!


I am very excited to get started on this project, but I need to build a few tools First ! more on this next week!


If you want more info on Larry’s wood gasifier see my post on What is a Wood Gasifier and Why you want to OWN ONE!

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84 comments… add one
  • We’re a group of volunteers and opening a new scheme in our community. Your site provided us with valuable information to work on. You have done an impressive job and our whole community will be grateful to you.

  • Bob

    You did a fine job. This gasification will be most needed soon as the economy dies along with the dollar, I'm interested in trying to build a small gasifier to run 500 watt gen-set [ very small ] to charge 12 volt batts. Then I can step these up to 110 volts A.C. with an inverter. Any plans out there for this? I'd like to see your next set of plans also. Keep up the good work.  Bob

    • John

      I agree gasification can provide renewable power in the event of an emergency or even a monitary collaspse.  Although there aren't any plans for a gasifier that size, I would ask what you would convert to AC current if your ownly using low power devices ? It would be better to stick with DC power if possible.  If you would only be powering low power draw applicanes you can use AC just be aware there a significant losses in power during the DC AC conversion.  With that said, If you want a 500 watt gasifier, Larry has told me that his gasifier design should be able to be scaled to any size, but futher testing wil test this theory.

  • Gergely Károly

    Wood Gasifier 50 kw I intresting.

  • john d hostetter

    Please get accurate data before making statemente like ' be aware of significant losses'. Many suppliers of inverters give performance data. And there are very good ones available. Secondly : why worry about 'significant losses' when the fuel is low cost and renewable? Using an AC inverter allows using appliances already owned….on need to invest in more, thereby using energy to produce. The goal is save energy not burn up more.

    • Jfedock

      I believe my information is accurate “be aware of significant losses”. You could experience losses, if your inverter isn’t efficient, that could significantly effect the project’s total installation cost. I agree that quality inverters can have low losses, but your current appliances could be very in efficient. My goal is to help people realize their own energy sustainability as quickly as possible. If buying a quality inverter, sizing your power source appropriately, while still using your current appliances is more economical, then that is exactly the path you should take. Depending on the age and efficiency of your current appliances, it may be more cost effect to buy a few high efficiency (DC) appliances (refrigerator, clothes washer, …) then to size your system to run your current appliances. You are correct, if you have a free fuel source (wood chips, saw dust, organic waste) and a high efficiency gasifier such as the one I am building, it really doesn’t matter. In the end it really depends on your power source. If your trying to supply all of your own energy from solar PV panels, then it would probably be cheaper to go high efficiency dc route.

  • here i can have more information and if the systme is ready to work in a combustion motor,if not here i can find more information and a gasifier to run a( gerador eletrogeneo) whith diesel motor.
    i have a small factory of pine nuts so i need electric power and have so sub-produts from extraction from the fuits(pine nuts)

    • Jfedock

      Yes, this gasifier should be able to run an internal combustion engine. If you are going to use a diesel engine (with out significant modifications such as adding spark plugs) you will still need to inject a small amount of diesel fuel in order to get the producer gas to ignite. You will use significantly less Diesel then you do currently, but you won’t eliminate it entirely. How much power are you looking to generate? or maybe a better question is how much waste from your pine nut plant do you get?

    009221 35340068, 0092-300-8287009

    • Jfedock

      This gasifier should produce enought heat to run an absorption cooler. I plan on investigating the possibilites of using both the gasifier and the absorption chiller in tandom to increase redundancy and efficiency.

  • I looking for design for plasma gasifying carbon black, can u guide with a DIY project on the same as well,

    • Jfedock

      I am not sure what your question is.. Please try to restate the question.


    i went through your demonstration it was very informative thankyou, i wanted to know what will be the temperature of the gas that comes  out of the gasifier. Do we get the gas at room temperature so that we can use the gas through controlled condition, i would eagerly look forward to hear from you.
    with warm regards.

    • Jfedock

      Since I have not tested the gasifier yet I can not say for certain what the exhaust temperture would be.

      I would think the temperture will depend on if you are running the water heating mode or the producer gas mode. I would be very suprised if the gas exited at room temperture since no heat exchanger is 100% efficient.

      Since we are extracting heat out of the gas in the sprial heay exchanger/water heater the gas should be significantly cooler then when it exits the inner hearth 1200F – 1400F ( 650C – 800C)

      I would guess the exhaust air would be between 30 – 50C if the heat exchanger is working properly.

  • I work as a Professor in Environmental Science at the University of Hadhramout, Mukalla, Yemen. I live in rural areas of Yemen, where there is no electricity and LPG cylinder cooking gas is expensive and sometimes not available. I wish to design and build a simple biomass gasifier for cooking purposes and I wish to spread this simple technology to the poor community where they cannot afford to buy this expensive LPG cylinders, therefore I seek your assistance by providing simple designs to build a simple biogas generator.
    Thanks and hope to get response from you to help the very poor communities

    • Jfedock

      I commend your efforts and would like to assist in any that I can. As for plan you can find plans suitable for your needs located on . If you have any questions please Send me an e-mail and I will help best I can. From your description Larry’s latest design should be perfect as it can be used to heat water or create a combustible gas perfect for cooking!

  • This blog has inspired me to continue focusing on my own blog

  • I just want to mention I am very new to blogging and site-building and truly enjoyed this website. Almost certainly I’m likely to bookmark your site . You definitely have remarkable stories. Bless you for sharing with us your blog.

  • Ernest

    Is there a name for Larrys latest gassifier?  I am most interested in producing electricity, ac/dc. Being in southern latitudes I will stick to passive solar heat as primary source. I can see where several parts are not required for my app. I understand the need for ceramic for the hopper sleeve and the hearth. Is there a great need for the primary air to be ceramic? The grate appears to see the highest temp, does it continuosly rotate to keep depleted fuel crumbling to hel p stop any blockages?  My fuel source be from utility crews clearing right of ways, did I read this could handle vast fuel shapes. Like coarse mulch. would recycling IC engine heat be worth helping heat primary air? I am considering driving induction motors from one ic engine,  how many? I would put a clutch on each altenator( induction motor) according to its available energy.

    • Jfedock

      This version of Larry’s gasifier is named the “Round John” in honor the hearth “roundy” for short. True it may have a few extra parts then would be required if you were only going to use the producer gas. I am not sure about “several parts” not being required. I guess if you were going to use the same size gasifier as the roundy minus the water heating capability then you could eliminate the air/producer gas combustor shell, the O2 sensor, and the Combustion air damper assembly. I would caution against doing this however. Removing the Water circuit you may want to increase the number of spirals for the exhaust to inlet air heat exchanger. You will want to make sure this heat exchanger is working properly because it will greatly increase the overall efficiency of your gasifier.

      I believe what you are referencing ‘I understand the need for ceramic for the hopper sleeve and the hearth. Is there a great need for the primary air to be ceramic?’ is the combustor shell where the producer gas is ignited internally to heat the water. So for your application no you wouldn’t need another ceramic shell, or a shell at all… just use the space to increase the surface area of the inlet to exhaust air heat exchanger.

      I inner great does not need to rotate continuously, but you are correct it is used to break up any ash or fuel bridging that will cause lower quality producer gas to run the engine. Eventually, i am going to build a automatic controller that will monitor the inner gasifier zone temperature and rotate the grate when fuel bridging occurs.

      Yes you can run wide variety of fuels including wet fuels with this gasifier. Dry fuel will give you the highest quality product, but wet fuel will work if that is all you have available.

      “would recycling IC engine heat be worth helping heat primary air?”
      Well if your looking for optimum efficiency that would be perfect. Now what would be really smart is to build the air – water spiral heat exchanger exactly as planned. Route the engine coolant through the water circuit of the spiral heat exchanger… You will probably still want a radiator and fan controlled by a thermo-sensor just increase the gasifier gets hotter then the IC coolant temp. YOu will probably also want to plumb in a few valves so you can isolate the gasfier from the IC engines cooling circuit. This will prevent the engine from overheating in the event that the gasifier and coolant temperature continue to rise.

      As far as how many motors … i am not sure that depends.. Larry thinks this unit should be able to power an 11 KW generator at full power. Especially when the engine starts pulling a vacuum on the gasifer increasing the gasification rate. I plan on testing this unit on a 11Kw generator once I can afford it. Your best bet is to just buy a generator and plumb the exhaust from the gasifier into the inlet air of the Ic engine. For gasoline engines you don’t need to change anything. Diesels you still will need to spray a little diesel fuel to get the mixture to ignite. IF you want to run 100% producer gas in a diesel engine you need to remove the fuel injectors and install a spark plug/timing system to control the engine.

      Hope this helps!

  • Great, thanks for sharing this blog. Much obliged.

  • matt

    I have heard of this technology and have a question:  Is it possible to store the gas coming from the gasifier in either gaseuos form or condense it down into a liqued form such as lp gas and of so do you have a plan for that?

    • Jfedock

      Yes, It is possible to store this gas just like you would store propane or any other flammable gas. I do not have any plans for this as I am not planning on storing this gas… I plan on storing it in the form of the fuel that is fed to the gasifier. if I need syn gas then I will just fire up the gasifier. Storing uncompressed gas takes up a lots of space and buying a compressor to store the gas in tanks (like scuba tanks) would be expensive. Look for a gas compressor online and a few scuba tanks.

  • Hi
    Storing wood gas at high pressure for any length of time will cause some of the gas to react. 
    Compressed gas
    Although it was technically possible to compress town gas or street gas, this did not happen because of two reasons. Carbon monoxide, one of the components of town gas and street gas, disintegrates quickly when compressed, while hydrogen gas, another component, leaks away through steel tanks when it is compressed.

  • Hi
    110,000 BTU heat is 35 kw heat.
    How much wood gas is produced?
    How large and engine can be run from this wood gasifier?

    How large would a gasifier be that could power a 5kw generator?
    I am looking for a gasifier that could power my electric car. 

    • Jfedock

      All we currently have are Larry’s estimates. This gasifier will probably produce enough producer gas to power an 8-11 kw generator. I am not sure how large of an engine you could run, but that is the purpose for my testing. I am fairly sure that this gasifier will be able to power a 5kw generator. Larry thinks the gasifier will have excellent turn down efficiency meaning that you should still be able to efficiently power a 5kw even if the system is designed for 11kw.

      I am in the process of gathering the materials and practicing my welding. Keep checking back for updates on my progress. After my gasifier is build i will be able to answer any question you may have about the performance of this device!

  • Bear

    May God Bless your good heart 🙂
    Just a thought , if gasifyer is going to run a small generator one could use the generator produced vibrations to assist with your fuel bridging issues by a simple custom same skid mount to transfer the harmonics where you need them 🙂

    • Jfedock

      Good Idea; Currently the grate has the ability to rotate and move up and down. If I find this is inadequate then I will look into building such a skid. Thanks for the good idea.

  • Bear

    I typed my email in wrong…when I registered 🙂

  • Jeff

    So John,
    Where are you up to with the build, quite a few months have by since you first wrote about this. Have you built it? Does it work?

    • Jfedock

      I have not built the gasifier yet, I am currently simplifying the design to remove the “water heating” heat exchanger due to manufacturing concerns.
      For a complete history of my progress thus far, please read my previous blog posts. If you have any specific questions please feel free to ask.

  • David B

    Matt asked the question in September 2012 if the producer gas could be stored?
    Back in the 1970's I with others investigated a local mill that had a gas engine which had previously driven the mill.
    Gas for the engine was produced in two retorts ( one being fired one being emptied / refilled ) which appeared to be a 1920's design of gassifier. To even out the fluctuations in gas production, the gas was feed into a very large tank ( gas holder ) which had a lid floating on a water seal.
    Some thing similar could be used with a modern gassifier to store producer gas. All that would be needed is a low pressure compressor to pressureise the gas holder and lift the lid.
    The engine then benefits from having gas supplied under pressure not suction.

    • Jfedock

      You are correct this would ensure the engine received the proper flow rate and mixture of combustion gases will be more uniform. This way you will be more likely to burn a combustible mixture with a higher heating value. The problem with storing gases is they have a very low energy density so you will need a big tank or high pressures in order to store any useful amount of gas. The problem with storing combustible gas at higher pressures is that it tends to be more dangerous. Acetelyene welding gases have acetone and a matrix in the tank to stabilize the fuel. It can be done just be very careful!

  • mike

    can anyone testify that this design works? i have seen a lot of talk but no evidence yet. thanks

    • Jfedock

      This design is similar enough to the “Imbert” type gasifiers used in WWII that one can assume it will work. The question is how efficient (how fast does the fuel burn ) and what is the quality of gas exiting the device? I am building this design to answer that very question. I am ready to begin the build, but still need to finish redesigning Larry’s original design to remove the water heating component as I only want to run a generator and don’t want to pay the extra money to heat water.

  • Dimitar

    Hello to understand why I ask these questions will give you some explanations. I own a small power plant 30 KWe. Consists of:
    – Similar type, but very simple gasifier
    – From a gasifier gas pipe reaches the turbine, which is the main purification of tar
    – From turbine, the gas reaches the scrubber with a water seal and ceramic filler
    – From scrubbing is supplied to the motor generator group
    Unfortunately gasifier, turbine and scrubbing only work well with wood chips up to 20 percent humidity and sizes from 1 inch * 1 inch * 2 inch to 2 inches * 2 inches * 2 inches.
    So I discussed the plans in detail and decided to proceed with production of the gasifier, but in my mind have been raised:
    1. where fuel is fed into the combustion chamber of the gasifier?
    1.1 Can be mounted auger, which feeds fuel automatically?
    1.2 Can be mounted sensor provides information to the auger when to submit fuel and when to stop?
    2. assume that the fuel is wood chips with a small footprint such as bran. Is fuel will go down to the core?Do not get blocked before reaching the core?
    3. high moisture content of the fuel will not prevent the cooling of the gas and its purification?
    4. if you want to use only the gasifier for the production of gas without heating the water to feed the engine generator group have to make changes in the design of the gasifier?
    4.1 Water heating is part of the cooling of the gasifier is it and therefore required?
    5. since it is not clear gasifier – 32 KWe with exactly these dimensions how much gas produced. If this gas is not enough to power an internal combustion engine which drives a generator 30 KWe. Is there a specific dependence increase this size to achieve greater production of gas?
    6.the diesel compression ratio in the cylinders ranged from 16 to 30. Do we decompress the engine within 10 to 13?
    7.I reworked diesel "Perkins" 3900 cc and decompressed within 12-13. supplier of gasifier and scrubbing oblige me. Over this compression gas igniting and what not. Many did not believe him, but I demands his fulfilled. Perhaps lying ….????????
    Forgive me for my English

    • Jfedock

      Let me try to answer your questions … I’m glad you are going to build one as well!

      “1. where fuel is fed into the combustion chamber of the gasifier?”
      This model is designed to be fed through the top lid. IF you are looking for an auger fed model you would have to make a slight modification to the top lid to fit a transfer/inlet duct from your feed system.

      “1.2 Can be mounted sensor provides information to the auger when to submit fuel and when to stop?”
      Sure you can mount a distance sensor (IR) on top of the gasifier lid (so it is pointing down toward the fuel) when the fuel level drops the sensor will turn on the auger.

      “2. assume that the fuel is wood chips with a small footprint such as bran. Is fuel will go down to the core?Do not get blocked before reaching the core?”
      Larry’s current grate is designed for wide variety of materials, but if you plan to use one type of fuel you will want to measure the average size of your fuel bran and then size the slits in the grate to minize the amount of fuel that can pass through the grate. The design of larry’s grate should minimize the amount of unburnt fuel from getting through it because of the overlapping (stacked) conical sheets.

      “3. high moisture content of the fuel will not prevent the cooling of the gas and its purification?”
      The issue with the moisture content in the fuel is that water requires a lot of energy to boil it off. Thus you end up using a lot of extra fuel to boil the water off. Larry’s design attempts to recapture this seemingly lost heat by cooling the exhaust gas below 100C to condense the water out of the exhaust stream. The heat removed from the exhaust stream is transferred to the incoming air before it enters the gasification zone. This way your are recovering as much of heat used to evaporate the water in the first place. With that said your gasifier will operate cleaner and more efficiently with dry fuel, but larry’s idea should minimize the effects of using a wet fuel.

      “4.1 Water heating is part of the cooling of the gasifier is it and therefore required?”

      Larry’s design requires you run water through the spiral heat exchanger. I am currenly redesigning the gasifier to remove the water heating feature. I am unsure if my design will have enough heat transfer area to cool exhaust below 100C .. I will post the test results once I am finshed testing.

      “5. since it is not clear gasifier – 32 KWe with exactly these dimensions how much gas produced. If this gas is not enough to power an internal combustion engine which drives a generator 30 KWe. Is there a specific dependence increase this size to achieve greater production of gas?”

      Your are correct this will produce about 32kWe max power but will not power a 32 kwe generator. Larry estimates we should be able to power a 10 – 12 kWe generator. Once again I will post the results once I am finshed testing.

      “6.the diesel compression ratio in the cylinders ranged from 16 to 30. Do we decompress the engine within 10 to 13?”

      You do need to decompress your engine and in fact would loose your efficiency. You have two options with a diesel engine. 1. reduce your injector dwell time to %5 of your original dwell and plumb the gasfier exhaust to the diesel’s intake. this way still requires a 5% diesel mixture to ignite the fuel during the compression stroke. 2. you modify your engine to have spark plugs (possibly removing the current fuel injectors) and plumbing the gasifier’s exhaust to the engine’s inlet. This way allows you to run 100% syn gas, but requires spark plugs and a computer to control the spark.

      “7.I reworked diesel “Perkins” 3900 cc and decompressed within 12-13. supplier of gasifier and scrubbing oblige me. Over this compression gas igniting and what not. Many did not believe him, but I demands his fulfilled. Perhaps lying ….????????”
      I do not understand if this is a question or a statement? I hope you didn’t reduce the compression ration of the diesel as your would have greatly reduced the power and efficiency of the engine. Please clarify your question.

      • dimitar

        Can my revised Perkins diesel engine running that gas with compression in cylinders 16. My equipment supplier,  recommend me to decompress the compression ratio of 12-13. According to him, if the compression in the cylinders is 16,the gas ignites himself

        • Jfedock

          That is how a diesel engine works with diesel fuel but not with producer gas (at least not to my knowledge) . From my understanding (I haven’t actually tired this yet but will soon) if you want to burn producer gas in a diesel engine all you need to do is plumb the producer gas to the diesels air intake and reduce the amount of diesel fuel sprayed into the cylinder to 5% of its original amount. The reason you still need a small amount of diesel is because if you compress only producer gas it wont ignite…

          If you want to run 100% on producer gas you need spark plugs in order to ignite the fuel.

          The reason why the producer gas won’t ignite on its own is probably because producer gas doest have the right air to fuel ratio ( remember the diesel is no longer receiving air through the intake its getting h2 and CO from the gasifier) . Because diesel fuel is specifically designed to ignite at these conditions once it is sprayed in to the cylinder the small amount of diesel fuel ignites thus burning the producer gas as well.

          Unfortunately reducing your compression ratio will hurt the efficiency of your diesel engine quite a bit… hopefully you have sleeved cylinder liners that can be replaced and you didn’t have a machine shop bore out your block..

          Hope this helps

  • Dimitar

    I did the following:
    – Dismantled the engine Perkins
    – I replaced the piston segments, valves, valve guides to work with such a LPG.
    – I changed the main and conrod bearings
    – I replaced the valve seats with ceramic-reinforced
    – Drilling of nozzles and beds made thread for candles
    – Install plugs
    – At the fuel injection pump actuator to put Delco
    – I connected it to the coil and switch
    I measured compression – 16 units
    Then the gasifier supplier and other installations purification said:
    – The compression in the cylinders is large and the tree will be igniting gas.
    Should reduce the degree of compression in the cylinders of 12-13
    Then to comply with these conditions, I decompressed the engine to 12.5 units
    My question is supposed to unzip the engine or the dealer lied to me?
    Anyway, at one point scrubbing stopped working and engine filled with tar and still need to disassemble it.
    So I want to know – This type of reactor it is reliable, it purifies the gas and giving me trouble.
    If you think that everything will be better, I do not mind it works and try it and inform you of the results.
    In this gasifier most attracts me the fact that it can work with various materials and high humidity.
    My English is not the best, sorry

    • Jfedock

      I believe what your saying is you have already done all of the necessary steps to run your engine off of producer gas only… I do not know what you mean by unzip the engine..

      I believe this unit should work reliably for you, but I am not sure what type of scrubbing system (if any) would be required. If I had to guess I’d say I’ll still need a scrubbing system with my redesign to run a generator, but I won’t know till my build is finished

  • Dimitar

    I forgot to ask:
    if the gasifier-powered 11 to 12 kilowatt electric how to increase its size so that it produces gas to electric power 30 kilowatts
    -diesel engine is revised Perkins, who normally burn 5 liters diesel per hour?


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  • Goran Rukavina

    Goran Rukavina from Croatia
    I am interested about small scale woodgas gasifier to run generator. In my country gasifications is big unknown. I saw what you write about yours gasifier. I want to make one. I have tools but dont have experience. Can you help me in that idea?
    Thank you in advance.

    • Jfedock


      Larry has already produced a full set of plans on how to build your own gasifier/water heater.  Give me more details about what you are looking to accomplish

  • Wow, wonderful blog layout! How long have you been blogging for? you made blogging look easy. The overall look of your site is wonderful, as well as the content!. Thanks For Your article about Learn the basics of how Larry Dobson& .

    • Jfedock

      I have been blogging on this website for about 2 years now.. Thank you for the kind words.. I plan to expand my website in to a full time gig once I finish my prototype gasifier build

  • Michial

    I’m curious, but all the web pages I have read about this type of generator about the heat being generated, but none of the designs do anything but waste the energy from the heat.

    I’ve read that temps can reach 2300 degrees, why not use the waste heat to power a Steam engine to either generate power, or a compressor that compresses the excess gas create for later use…

    • Jfedock

      There are many great options for the waste heat from a gasifier {Home (air) heating, water heating green house, increasing the efficiency of the gasifier}. It really depends on your situation and climate.

      I wouldn’t consider a steam engine as a viable use for the heat because of the low efficiency of such and engine. Steam engines tend to have efficencies around 5% or so.

      Once my prototype is build I plan on investigating many different ways to utilize this “waste” heat.

  • Vern

    I have read all the comments and it seems there has been no forward progress on anyone building this gasifier unit.
    Are there any build comments, revisions or updates??
    Seems credibility is failing as time moves on without any build updates

    • Jfedock

      Thank you for the feedback. I realize the build is long over due; I would love to begin the build process! I need to make sure the build will work for my plans. You know the old saying measure twice cut once.

      With each 3D cad build I am improving the design, reducing manufacturing time, and cost.
      I completely understand REAL WORLD results are important and there is no substitutes. I will build this Gasifier. I need to make sure all the money, time and effort do not go wasted!

      Give me one more shot… I promise I will not disappoint

  • dean de loof

    super efficient panelized cabin, i have a design. i want to power it with 12 volt converted to 120. i know this would not be as efficient as we would like, but i would want air conditioning. get back to me.

    • Jfedock

      You are going to need to buy a lot solar panels to run a Central AC system. Your looking at the $40,000-60,000 range for the panels alone. The first thing you need to do is to reduce the amount of power requirements as much as possible. I suggest using super energy efficient appliances, lighting, and heating. Look into getting a gas stove and heat if possible.

      You could build a gasifier to provide heat, stove fuel, and Power if married with a generator(You probably still would want a few solar panels, just not nearly as many (<$2,000 worth)). This requires a renewable carbon source to power the gasifier but if you live in a cabin you probably have access to a lot of fallen trees and limbs.

  • Larry Phelps

    I enjoyed your video. However not being computer saavy I can’t find the web site to get the plans to build one of these things. Can you help me find the site. Thank you

  • shane

    do you think a gasifier could be made out of a Hardy heater? I have one that i use to heat my house and water with.

    • Jfedock

      It looks like a professional “rocket” type stove. It operates on a different principle then a gasifier would. I am sure you could convert one, but the amount of work and time may make it easier just to start from scratch. Probably your biggest hurdle would be the accellerated oxidation of the stainless steel in the firebox area. A gasifier will most likely require a ceramic / high temperature refractory core to surround the gasification zone. Gasification zone temperatures can be 1300 – 1500F which is out of the function temperature range for most stainless steels.

  • It’s genuinely very complicated in this busy life to listen news on Television, thus I
    simply use internet for that purpose, and get the most up-to-date information.

  • Hi Mr Fedock
    Hi have a Wayne Keith gasifier powering my saw mill.
    I was looking for plans to build a green sawdust gasifier.
    My mill produces about a ton of sawdust a day that is a big headache, I was thinking if I could use that saw dust as my fuel stock it would kill two birds with one stone so to speak, get rid of my sawdust and not have to process fuel.
    Here is a you tube of my startup.

  • Adam

    Hey I am a huge fan of gasifier technology and anyone who attempts to make one. I had to take the time to let you know what an awesome job you did and that you’re setup is exactly what I am going to do myself. I would be really grateful if you would be willing to chat with me if I need any help when building mine?? Either way you did a really awesome job at this and I am a huge fan of your setup now as well.

    • Jfedock

      Thank you very much for the kind words. If you like what you have seen so far then you will be very happy with what is still to come! Soon I will release videos on YouTube detailing how to complete the more complicated tasks (i.e. welding 20 gage stainless) Check out my YouTube channel for more updates and in depth videos of the design.

  • Are you up and running with the Dobson design of the wood gasifier?

    If so, do you have time to talk?


    • Jfedock

      No, unfortunately my welder broke then I started getting harassed by code enforcement and now am in the process of moving. I plan on resuming my build in month or so. Check out my youtube channel for my progress so far!

  • I have been searching through mountains of material over the past few months and somehow found this video of you running your household on the gasification unit. It was very good. My problem is that I can not find any good blueprint plans for building my own unit. Everywhere I look sounds promising but I find not much. I first want to build a gasification heater to heat my greenhouse (3300 sq ft). I have lots of plans for small stoves etc, but nothing more. I have found some places to buy plans but don’t know if they would work as I can not talk to anyone. If you can help let me know. I am not sure if this is an active site as the last post I see was in 2012. God Bless

    • Jfedock

      Yes the site is still alive; I have not been active lately as I recently moved and have yet to continue my gasifier build. I check back shortly as I will be building / testing my prototype soon.

      I currently do no have have a set of plans for my prototype, but you can find plans for gasifiers on

      • Thank you for your response,but it cut off the address of the web sit I might find some plans.

  • Prince Mugisha

    i am from Tanzania, and i was impressed with wood gasifier and would like to build one, this tech can improve life of millions of people in Africa, please can anyone send me simple DIY as i got every material needed but i need a blue print.

  • richard kimaro

    mr larry am one of the scientist ,reseacher i have been devoting most of my time into different scientific projects and one of them is gas fire i would like to have your email,phone number,

  • richard kimaro

    recently i ordered a gas fire from china which uses rice husk,sawdust.but the gas uptake is not working well, and the gas outpust is not satisfactory,no consistency of the output gas,how do i solve this problem

  • You are so interesting! I do not suppose I have read through a single thing like that before.
    So nice to find another person with a few original thoughts on this topic.
    Seriously.. thank you for starting this up.
    This site is something that is needed on the internet, someone with some originality!

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