Can pyrolysis oil be re-gasified to fuel a gas engine?

Hi I am new to this site but I have experimented with wood gas for many years. My goal has been to run my irrigation pump engines on wood gas. ( I am a farmer in California raising Almonds)
I want to re-gasify pyrolysis oil in a retort, it may need to be steam reformation, to produce a gas that is manly CO, H2 and CH4. I am trying to produce a gas that is a higher BTU than producer gas is. I saw a flow diagram for making green diesel that followed my idea except I want to run a gas engine instead of making green diesel in a fischer tropsch reactor. I would appreciate any information or experience that any one can share.


Welcome to the DOW KenS,
See if you can clean up this link for viewing.

→ Renewable Methanol (scroll to that page’s bottom)
→ MI report 2019
The page 9 flow graphic shows the gasification of wood → to syngas place in possibilities.
See then pages 12 and 17 for other process steps graphics.
Your answer is, YES.
But . . . many steps even just to gaseous, without going farther into a motor fuel liquid.

Then look at the reformation plant pictures on pages 14, and 24.
You would have to make a down scale sized similar to make enough fuel gas to feed hungry irrigation pump engines. And this will certainly not be hands-off.
Be a big jump from a fellow able to operate a nutshell/tree trimmings to woodgas maker, versus a reformation plant.
Can your orchard afford this expensive human operator?
Can your food growing orchard afford the drive-by visible exposure of a scary-dangerous “chemical plant”?

You are California.
I am Washington State.
CA, WA, OR main cities now are Eco-Activists centers.
Up here they killed the Waunna, OR woodchip to methanol plant; the Rainer OR nuclear steam-electric plant. Killed the building of a natual gas to methanol plant on the Washington side of the Columbia River. The Centralia coal steam-electric plant has survived only by being invisible from I-5. No longer using the local brown coal, the five trains a week of Montana and Dakota’s better coals have to be least visible run past parallel I-5 and Columbia Gorge I-84 and SR14.

While processes and reprocessing may be technological feasible. Even economically feasible . . . will it jump the Eco-Activists hurdles?? They vote their beliefs. And they are now sold on central distributed out electrical power. Made somewhere else. By someone else.

Stay small. Direct use fuel gasify your nut shells and trees trimmings into upsized larger pumping engines. This uses up the hot internally made woodchar to fuel gas convert the hot internally made pyrolysis made gases. Low. low pressures. Manageable heats. With smaller, less visible, scary to lookie-lou’s, systems.
Steve Unruh


Hello Ken,
I suspect that you could drizzle your pyrolysis oil into the air inlet off a charcoal gasifier. This idea comes from Garry Gilmore’s Ranger pickup video where he drizzles waste oil. What is your source of pyrolysis oil?


It was great to see Gary’s video again.


Steve, Thank You for the welcome and your comments and information. Yes I do live in California so I will need to not be very visible. I live in the north part of the state so it is easier here.
The hurdle I have with directly using tree limbs (prunings) in a gasifier is being able to chunk them so the chunks will flow down and not hang up in the neck of the gasifier. I have a chipper and a grinder so I can make the limbs into small wood chips that would be the right size to make bio oil with fast pyrolysis. I have the auger part built for a fast pyrolysis unit I just need to finish the project! And start making bio oil to experiment with. I need to do something, with almond prices low from the Corina virus shut down, I don’t have the money for fuel for pump engines but I have a big pile of wood chips!!!
Is there a gasifier design that bio oil can be gasified in? ( put rocks in a gas gen gasifier and dribble the bio oil in from the top :smiley:)
Ken S.


Thanks for the additional details KenS.
Yes. The shut downs had cost my Wife’s CNA training school dearly too. An excellent employee have to let go after four months in with no students to manage. Two contract Instructors with no work. A single mother CPR Trainer not used.
$30K, then another $17K fixed expenses to have to pay out with more consequences to come. Versus ~$200K in lost incomes.

Open up Bob Mackeys avatar above for his woodgasing his Dakota pickup topics. He is in the Washington State stone-fruits center and raw-wood chunks gasifies successfully. And is now charcoal gasifing too. Ha! Ha! Hardwood’s tree crotches.
See how he is handling fruit tree hardwoods.

So far as an oil eater gasifer; Gary Gilmore’s, RindertW linked to, shows this as simple as can be done. Then Eddie Ramos’s system in Brazil. Charcoal; enhanced with wastes. Simple.

I do not mean to be critical, but it seems to me you are adding too many steps for a direct use system.

“Fast pyrolysis” to make bio-oil??
Have any info links to this you can put up?
Steve Unruh


Hello Ken.

This whole pyrolisys oil isnt quite clear to me. Is there a reason why you want to go trugh the trouble with it when runing a stationary engine straight from a producer on wood chip fuel is well understood and countlessly prooven?


Hi Ken, it is good to have another west coast member wanting to do some gasification for running practical machinery like a water pump for irrigation of your orchard.
Keep it simple is one of the main keys to success. Here on this site there are many gasification builds that have done this. Look around at the many builts Charcoal being the simplest and then the wood gasifier builds. The cool thing is they both work. It is just the type of fuel in the pyrolysis stage that is different and that makes the gasifier complexity different.


Hi thank You for each of you comments and questions. I will try to answer some of your questions and give some more reasons why I am trying to use pyrolysis oil to run an engine.
One reason for going the pyrolysis oil direction is wood chunkers are not really available but wood chippers and grinders are very available. The first PTO chipper I bought made a very small 1/4 in. chip that is the right size for a pyrolysis oil reactor.
Another reason is my irrigation pump engines uses around 100 gal. of diesel fuel a day which is about the same as 2000 Lbs. of wood. That is a lot of wood to chunk with a saw! Also my pump engines are sized to the load and are not able to have the 25% to 30% loss in power. This is the reason I am trying to make a higher BTU gas using pyrolysis oil. One of my pump engines is a propane engine that I sized to be able to run on natural gas; so if I can make a gas that has about the same BTU as natural gas then I can run that engine.

20 years ago I was trying to make a higher BTU gas by making charcoal in a retort I built. I caught the gasses in a tank and when I burned them a few days later the gas started to burn as a light blue flame typical of wood gas then it changed to a heavy orange flame. ( methane?) I also made a black liquid that I later learned was pyrolysis oil.

The idea of putting the pyrolysis oil in the air intake of the gasifier would work.
Ken S.


First of all, there is no need to make chunks for a gasifier. Countless wood chip sistems exist.

Pyrolisys oil or tar is the nasty thing we all try to avoid geting in an engine. Haveing anything to do with it is risky.

Im afraid adding the oil to the gasifiers air intake will not make more potent gas thain a wood gasifier does. Because then it becomes just a more complicated wood gasifier.
Think of a wood gasifier like this. It consists of a charcoal gasifier (charbed) and a charcoal kiln (hopper) where wood chunks or chips break down to charcoal and oils prior to being combusted.

If power is the problem, then the solution is not being a purist. Runing hybrid will solve your problem. If you run 75% woodgas 25% petrol mix the power drop will be minimal.


Sounds like pretty big heap of wood. Are you sure your almonds produce enough wood to satisfy the investment into gasification? No matter of that, I agree with @KristijanL , that hybrid or dualfuel would be the best choice for you.


ChuckW turned us onto some info I think you might be able to use.


Thank you for the explanations, KenS.
So, your 100 gallons of fuel oil a day is for days you irrigate.
And that is one day a week for each section of trees? Correct?
How many days a week must you operate the pumping?
How many irrigation days a productive season must you irrigate operate?

I think KamilK was correct you can not possibly have enough self generated tree pruning/thinning/culling to annually supply your needs.

Using wood-for-power any system that throws away 25%-35% of the energy potential will be in a deep dark energy hole.
O.K. if you own a timber lot watching overgrowths and weather damaged fall and rot on the ground.
Some here love charcoaling. O.K. . . . (only using the white chicken breast, so’s special breeding hybrid breast makers. Saddest chicken we ever raised)
Your pyrolysis oil is only a possible 10-20% of refining down whole raw wood.
So, is the charcoal portion sold for a side income stream? A few come here to the DOW where that is their primary concern.
And they come asking the reverse. What can be done with the wastes off-gases and tars?
And some fryer oils diesel drop-in substitutes have come here asking how to gasify their accumulating barrels of heavy glycerin’s contaminated with methanol. Geez Dude. IF it has a fuel value why did you not focus on the using it up in the power making engine directly??

Most here are trying to direct use all of the wood’s energies, as directly as possible. So wastes and fractional utilizable thinking is not in our pursuits views.
Only interesting are DIY integrated systems that can evolved to 70% cycle full use efficiency. My bulk in-house wood stove sets this standard.

No offences intended. Just explaining the responses you will get.
Steve Unruh


Sounds to me like a hybrid diesel or diesel-electric system with wood-gas as a range extender to lessen overall fuel cost. Like Patrick Johnson. Build the whole thing on a skid or trailer structure. :cowboy_hat_face:

Ken, If you can build a refinery for pyrolysis oil, you can certainly build a wood chunker. Several proven formulas exist that could even be partially automated. maybe start a sawmill side business and have lots of scraps to use for fuel.


Do you shell the almonds? I’m not familiar with the shell. My almonds come in plastic bags, but I am familiar with burning cherry pits and they burn super hot. I believe many other pits and shells have the same BTU value. If almonds shells are the same it seems like an Ideal fuel source.


I can’t add much technical help but will add a caution. When I got into gasification (for a Fischer Tropsch project) in '08, I worked with a couple of chemists. One of them gave me some pyrolysis oils to “play with” as I’m in the industrial chemical business. He cautioned me that not only did it stink to high heaven, it contained lots of really toxic components.

Be careful handling the oils!


Yeah, its preety much what gives ciggaretes their hazard to health…

Tod, have you shared your experiances wih the FTS reaction here?


Hi. to answer the question if I have enough wood to run pump through out the irrigation season? The answer is yes! The irrigation pumps run 3 to 5 days a week April through October, less at the beginning and end of the season. I use around 5,000 gal. of diesel fuel and 10,000 gal. of propane per year. On the wood supply side; I sell 20 cord of fire wood per year and then the pruning’s that I chip, 25 to 30 tons per year. Also I am 200 acres surrounded by 1000’s of acres of almond orchards. Some of the pruning’s are ground up and left in the orchards which is good but a lot is pushed into piles and burned.
I am realizing the direction I need to go is a gasifier that is designed to use wood chips and continue to use some diesel or propane so there is not much power loss as Kristijan L. suggested.
Can you give me a link to wood chip gasifier plans?
Thanks for all the suggestions and questions.


Hello Ken, I am almost a beginner in the world of wood gas, but let me express my opinion on your situation:
-5000l of oil = 50000 kWh of energy
-10000 gall of propane (38000 l) = 250000 kWh of energy

so together you use 300000 kWh of energy, if we say that the efficiency of the motors is 30% you actually need 90000 kWh of energy to drive the pumps

-if we take 30,000 kg of dry wood = 120,000 kWh of energy, which would at best produce 30,000 kwh of propulsion energy, …

so I can easily conclude that you only have a third of the energy needed in wood, but even that is already a good proportion.
How powerful are your engines? Have you perhaps considered using electric motors for propulsion if your location allows?


Hey Ken,
With that level of power use, you would have a reasonable payback interval with a commercial offering.
Doubtful an R&D project is what you want when the pumps really must be working.
Quite a few offering out there for chips to electric power, but buyer beware.
Here is one western company with quite a few installed and running plants at the scale you are looking at, using a fuel you seem to have:

Don’t know much about them except through the testimonials.
They seem to be using parallel, hopperless, downdraft gasifiers to scale to the desired output.