Automated gasifier for syngas-gasoline hybrid engine

I am new to gasification, and I have done a ton of research on the subject. I want to build a small unit that will supply a supplemental, steady stream of woodgas to my engine in a 1998 Honda Civic. It is a fuel injected engine. I plan to use a constant flow gas valve to control the flow of the woodgas into the air intake of the engine. The engine should regulate the gasoline it uses automatically.
I am looking for a way to automate the whole process of gasification. Here are a few design ideas I had, and I would love some feedback:

  1. An electrically heated gasifier. Basically I would use an electrical coil, powered by the alternator and car battery, to generate heat inside the wood container chamber. This heat releases the syngas in the wood, which is fed into the engine. Part of this power is used to heat the gasifier and power the gas cooling apparatus.

  2. An autostart, two container gasifier. This would use an upper “monorator” container that holds the wood to be converted to syngas, and a lower burn chamber to supply the heat. An adjustable valve would be fit into the top container to supply the right amount of air for gasification. This would be adjusted and left alone. The bottom container would hold additional wood, which would be burned at high temperatures in order to heat the upper chamber. This chamber would be supplied with a high amount of air, by using an electric blower. This blower would be regulated depending on how much woodgas is needed.

Basically I want to get rid of the tedious process of starting the gasifier, as well as cut down on setup time. All I want to do is load in dried mulch or wood chips, and start the gasifier with a press of a button. I realize this is a tall order, and probably the holy grail of woodgas generation, but I think it is something that needs to be looked at seriously, because it will be much easier for non-technical people to operate.

Please provide any and all feedback. I realize I am probably naive and need some people to tell me how it really works. That’s why I’m here. I want to avoid any and all mistakes that I can.

Welcome to the site Colby.
A lot of us have came to this site with big ideas of how we can improve on what is out there. Maybe some of these ideas can work and maybe not. The fact of the matter is, we need to start with what is known and proven to really grasp the concept of gasification. I myself am still learning. I would strongly urge you to obtain a membership. With a membership, not only will you get one of the most efficient designs out there to run a vehicle, but a lot of people that will assist you in the build. There are so many variables and factors involved that just can’t be understood by reading on the internet. Building a gasifier and running an engine with it will move you towards a better understanding. It’s my opinion that once that step has been achieved, one can move forward and introduce their ideas to add on their system. I am one that came here with big ideas, tons of hours on the internet and even built a working unit. My unit had many flaws but I didn’t know why and what. That is what this site will teach you. A lifetime membership here would have saved me a lot of money and time had I started here first before my build. You are one step ahead of me.
Again, welcome to the site.

Draw a picture of how you envision your internals of your design… give us something to look at and critique… most of us here try to be helpful where we can be. That being said, if you’re trying to do something that has never been done before you may just have to do it… and find out what the results are first hand. Look forward to see what you’re thinking in this regard.

Just a note on your concept of woodgas production… it’s not just “heat up some wood”. That may look good on TV but that’s not gasification. That’s actually called pyrolysis. in short order your engine will seize up with tars. There are several more steps in the gasification process, pyrolysis is only the first. You must have combustion (of the pyrolysis gas), reduction in a charcoal base, and cooling/filtering of the gas. Now you have a clean syngas containing no tars, ready to run a motor. Very different than pyrolysis gas.

Steer clear of the mulch. Most of that stuff is full of long stringy wood, bark, dirt and leaves, which don’t work well. You will do better with uniform chips or chunks of wood from a known clean source. Most vehicle gasifiers need chunks, from egg size up to fist size is perfect.

One final note, “the tedious process of starting the gasifier” takes me about 2-5 minutes, mostly to load wood and wait as it warms up. Once lit it will go all day, through several starts and stops.

If you’re really after a push button start, check out how Vesa Mikkonen starts his units. No automation. Ekomobiili wood gas-generator - YouTube

Note that he’s in no hurry. His systems cost $$$ because of the stainless and the sophisticated control and filtering systems he uses.

I was under the impression that you could filter out the tars in the pyrolysis gas and feed it into your engine. Do you mean that you need to break down the tars in the gas by burning it off (or cracking the tar)? I have heard there is a low temperature method that produces more tar, and therefore requires more filtering, and a high temperature method that “cracks” the tars so they don’t need to be filtered out.
I guess most of what I want to cut down on is the time it takes to set up the wood in the gasifier. I have researched how it is done, and it looks like it needs to be in a specific kind of configuration to burn well.
Also, about the mulch, I have researched what is called a “monorator” that is supposed to work with moist wood. Not sure if this is legit, has anyone tried it? I can get free mulch from my local landfill so I would really prefer to use that.

My experience is you can’t filter tar, what are your sources that say you can. I’d be interested in reading that. I don’t believe you can crack tar either… you can burn it in your gasifier and use that heat to generate wood gas though… my 2 cents on that topic. Do you have a reference as to where you seen a monorator that can use wet mulch? I’d like to see that.

Again, I suggest you draw a picture of your idea and post it… or are you looking for some one to do some designing for you?

Here is the article on monorators:
I watched this video on how to run your truck on woodgas:

This video, and the 16 after it, have taught me a huge amount on how these work. In the description the video publisher says that it can be run on almost any organic matter. The woodgas is fed through a series of metal tubes along side the truck. The tube changes direction many times, and traps tar at the end of the tubes. The tar drips down and is collected at the bottom. There are also filters using hay and other materials that trap the rest of the tar. Another thing he uses to trap the tar is a “cyclone filter”. It basically uses the same approach as the tubes. It changes the direction of the gas, swirling it inside of a canister. The tar collects on the outside of the canister and is collected at the bottom.
I have heard the term “crack tars” a lot, and I think it just means getting the tar to a high enough temperature so that it burns.
One thing I forgot to mention is that I would have a microcontroller that reads the temperature in the burn chamber using a thermocouple, and regulates it to the optimum temperature by controlling either the amount of air that feeds the burn chamber, or by regulating the current through the coils. It depends on which design I go with. I have attached pictures of my two ideas. Thanks for your input.

Ok, I’ve read that on monorators… i don’t recall seeing where it talks about using mulch… pretty sure all the systems that had a good performing monorator used chunks. the USSR had a system that used green cord wood for large machinery i’m told… not sure if it would scale down to the size of vehicles we want to use thougjh.

I’d take everything uttered by that Mr teselonian with a grain of salt. I had asked him very simple questions on gasification and he never once allowed my questions to be viewed on any of his vids let a alone answered them… as far as i’m concerned he’s a quack…

The systems you’re suggesting are more like destructive distillation… You can make wood alcohol or methanol like that I’m told… You can try it if you wish, but there are much better ways than that to run an engine. I do really doubt you’ll ever filter the tars out that it produces…

five minutes of my life i can never get back……….


Well Cody, I wish it were that simple, but it’s not. In your first design, It would take far more energy in the form of electricity to heat the wood, then you would get out of the wood gas, and what is left is charcoal, which is a good fuel, but there is no way there to use it. The second design simply uses a wood fire to heat more wood, which again leaves charcoal, and the “exhaust port - exits car” is the unrefined wood gas you need to run the car. I don’t know how old you are, but if you like to read, you could start with the Embert design which worked for thousands, (maybe millions) of people during and after WWll. It is a proven design, that incorporates a monorator wood hopper, and is the basics of designs that followed. Our FEMA has a design to look at also. At the top of this page under “Learn” and “Resources” there is a lot of historically accurate data that will get you headed in the right direction. And as a paid up member of this site you can also learn all the details of a working WK system. You will find the recommendation here, is to start with a working design, then make improvements. It’s not that easy, and it’s not that simple.

Here is a direct, unedited quote from my collection of “Steve’s Book of Wisdom” that I complied several months ago - good advice then, good advice now.

“Take the advice many systems now experienced Dutch John put up here on the DOW:
“On your first gasifier build up a known design (exactly as presented to get your first experience.” “Then later experenced you can try your own ideas” He’s had his own “better idea” failures.
One of MikeL’s greatest expressed frusterations is on his offered up double brake rotor design fellows elaborate, fail and then blame his concept.
Read super smart Chris Seanz collage of “better ideas” “that did not work” on his first self build up experience. His Wayne built up worked right out the gate. Couple of problems later on due to a Chris “It’ll be OK” Wanyne, “OK. Your system. Give me a call if you have a problem”
Expereinced Wayne himself has a system heat expansion cracking failure in the last 12 months 'cause he changed just one little thing from his proven bread crumb path.
Dr Tom Reed says many of his attemped systems did NOT work.
The saddest thing we all of us now having done it see are new guys build thier own way, or worse by polled ideas and selected listened too opinions, fail to make a working sysem, tip all of that work and effort into the scrap and walk away cursing.”

Hi Colby,
On the website here, you’ll find plenty of old books with old knowledge about the basics of wood-gasification.
If you read them carefully and pay attention to the real process what takes place , then you’ll understand that there is more then one way to skinn the cat, but still unavoidable facts are;…
Gasifying material needs energy… a lot of energy…
Your 2 idea’s will gasify the wood, yes, but…

First: gasifying = heating any material at an temperature that it becomes gaseous and stay’s gaseous ( putting it simple )
The endproduct is a cracked original material ( breaking the molecular links by heating )
For example H2o aka water becomes Hydrogen and Oxygen

Same goes for the “tar” products, depending their consistence they will be “cracked” at certain levels of temperature and dwell times to become a single molecule again ( i try to keep it simple )
Depending the volatile contents of the wood, some chemicals can become very nasty…

Using only heat without the presence of oxygen aka pyrolysing will create you an useable gas, depending the input material
Up to 85% of the organic material can be converted into pyrolise gas, rest wil be pyrolise oils and ashes
The process will need its heat from an external source.
The gas will be containing almost zero % nitrogen

Using heat with restricted oxygen supply aka thermolyse
The material itself will provide energy for the different processes, partially combusted…
The different reactions in the gasifier , more important the reduction zone, will convert the gasses from the combustion zone ( cracking-zone ) into useable gasses ( CO, H2, CH4 mostly )
More heat and sufficient dwell time in the reduction zone will determinate the amount of tar left in the gas.
Gas will contain nitrogen.

If you look at any single aspect of an existing gasifier system then i agree that things can be automated but at a high $$ and not so simple, as already stated in above postings.

You studied a ton already ? Back to the books for another million i would say :wink:
Keywords: woodgas, syngas,… Carbon’s, Hydro carbon’s…

Hmm, you said that heating wood without the presence of oxygen will create a useable gas? That is what I am trying to do in both designs. Did you mean an unusable gas? Because if it is useable then why wouldn’t these designs work?
I have seen many, many designs that filter out the tar from the gas using various methods… and I realize that these tars can be broken down into more gas, but I want to keep it simple. I have an excess of wood so to me it doesn’t matter much if I am efficient with it. I could probably use the tar as a fuel in the burn chamber in fact.
By the way, I am 23 years old, and recently graduated with a BS in Mechanical Engineering. Just so you guys know what I will and won’t understand etc.
From my understanding, pyrolysis produces combustible gas with tars in it. These tars need to either be filtered out or turned into more fuel.
Oh and I found this Wiki page that describes the energy balance of a gasification system:
I have done some energy conversion math, based on what mileage people usually get from their woodgas vehicles, and have come up with an output energy of about 13000 kJ/kg of wood. According to the Wiki, it should take around 4000 kJ/kg of wood to run the process. This is a net of 9000 kJ/kg. So theoretically an electric heat supply should work… however that is a huge amount of power to supply so it would be unlikely.

Pyrolysing = heating the “wood” without oxygen.
Put simple,… more heat during pyrolysing = more gas , less tar
But also many possible new reactions in mixing different components again.
Yes tar can be “filtered-scrubbed-trapped” and reused as fuel.

Pyrolyse gives a useable gas.

I am not sure the figures you’r mentioning in the math are useable, i have checked the link you provided.
Better look up the figures on the documentation provided in the resources section ( treatise on gas producers for example )
These provides more general and excellent numbers which are still useable.

Try to calculate how much energy you’ll need to make an , for your purposes, useable gas from 1 kg wood.
Also take in account that at the end you are converting carbon into gas. ( look wikipedia for carbon )

Energy balance : rule of thumb… 3kg wood ( dry mass ) substitutes 1 liter gasoline
3Kg charcoal substitutes 2 liter gasoline.

If wasting wood is none of concern, then first turn it into charcoal for starters.
if you are mastering charcoal gasifying then switch to raw wood.
Making an automated system with charcoal would be much easier to start and learn. ( one of the projects i am working on )

I myself keep myself humble busy with charcoal, bringing myself to a next level. still learning from the experiences from the others and from the past projects ever build.

You also could jump into the water, presumed you are a good swimmer, and try to build an WK gasifier, automated. More to learn, better results then other commercial builds.

You’r idea’s both will work, but will also need external energy for the conversion wood-gas.

Don’t waste energy on an apparatus for cooling the gas, try to use the heat to preheat air and feedstock.

Gasifying is basically old technology… so read old books if you can, they are worth it to read.

Read back some topics from others here on DOW, they contain good , valid information, useful to make decisions.

Anyhow, have questions, ask, but please also read the articles in the resource section, you know how important that knowledge is after you’ll read it.



I will say one thing only. Tar WILL ruin your engine! Nobody driving on wood intentionally makes tar then filters it out. Tar is an extremely microscopic particle yet it conglomerates easily into a large mass. It will either pass through a filter or clog fine filters quickly.

For all practical purposes, once you’ve made tar you can’t get rid of it. The effective cure is prevention - don’t make tar in the first place. Burn it inside the gasifier, make heat and drive the gasification process. Gasifier design has centered around this principle for the past hundred years.

Yup to what Chris said.

Hmm it is true that cleaning out tar from filters constantly would be a pain. I have heard you can run it through wood chips, which catch the tar. Then you use those chips in the burn chamber. Another method I have seen for producing tar free gas is subjecting it to very high temperatures:

Here is a cool paper on removing tars from the gas at low temperatures:
I haven’t read through it all yet but I will soon.

wood chips won’t catch all the tar, and I use chips in my filter.

Reading all these articles is a great idea if you want to study gasification. If you really want to understand wood gasification, you need to operate one. It is so hard to sift through what is on the internet that will give you a true understanding. It may only confuse you.
To operate a gasifier you need to do 1 of 3 things. One can purchase a a turnkey ready to run machine, 2: GEK has all the parts stamped out and then only assembly is required or thirdly get a welder and some scrap metal and follow a design.
I chose to scrounge up some material and put together something to make wood gas. Then I was really hooked. I through that away because I then discovered the actual temps inside burned through the metal I used. I then applied more reading and videos. Within 2 months of discovering wood gas, I was able to run a 12 hp motor on wood gas. I found out I was extremely lucky that I didn’t produce tar and ruin my engine. At that time I wanted even more understanding and found this site. If you want real life experiences that provides a more focused understanding, this is the place. I visit this site everyday just to read posts when I’m not working on my project. I pick up very useful tidbits every time. The articles one can find may not be applicable to running car engines or small engines.
I say, grab a welder and get your feet wet, well not literally but figuratively. After you have a unit and can burn wood, you will know which articles you are reading will be applicable to what you need to learn. Then the fun begins. Wood gasification ties a lot of things together. Science, engineering, plumbing, welding, chemistry, etc. The best thing about this site is all those people are right here. Once you start cutting and welding metal people here will chime in with some tips.

Bill S

I am definitely going to experiment for sure, that is the most fun part! Obviously I am not going to experiment right away on a car though. I think my first step in testing will be to burn the gas off and see if I get any tar out of it. My biggest concern right now is getting clean gas. Next step will be running a small engine off of it, maybe a small generator… basically the cheapest thing I can get my hands on. After that I will work on automation, ease of use etc. before I make the final design to put on the car. Right now I am just looking for a reasonable place to start. I really want to make a gasifier that can run on almost any organic matter, which is why I chose a two container design. It seems relatively simple to heat a container full of organic matter until it gives off woodgas. Yes it will contain a large amount of tar, like many people have said. I think it would be extremely beneficial to discover a way to trap this tar and reuse it in the burn chamber. I will keep researching this and experimenting. I will look at all the existing designs but so far I have not found any that can take a variety of sizes and types of organic matter without producing tar. My goal is to run a car on mulch. Maybe it’s impossible, but I want to experiment anyways.