Introduction: Charcoal Powered Generator - Gasifier

Picture of Charcoal Powered Generator - Gasifier

Ask any farmer, survival expert, Boy Scout, hippie or prepper and they will tell you the awesome uses for charcoal. From improving your garden to filtering water and field medicine. But did you know with a few scrap parts you can run an unmodified internal combustion engine?

I've been interested in alternative energy for a long time. I wanted to find an inexpensive, scalable option that could work in virtually any inhabited part of the world. People are smart and creative. I knew there must be something out there. After lots of searching I found a very cool theory. It was not on a fancy tech blog or news conference. I found my answer in a grainy video on YouTube. An older man wearing dirty bibbed overalls who introduced himself as "Gary from Pennsylvania" He had a new take on a very old idea: Charcoal Gasification. I found this both brilliant and fascinating because I had been considering building a wood gasifier for years.

Following a rough outline of what I could see on his video I was able to build a functioning proof of concept using mostly junk parts: A metal 5 gallon bucket with lid, random valves and pipe fittings and a piece of PEX. Obviously my first try was raw and intended for rapid prototyping - but it worked, it was cheap and it was fast. I successfully ran an unmodified internal combustion generator engine purely on the gas produced by burning charcoal.

This has the potential for many benefits on the modern homestead, those to start freeing themselves from petroleum dependance, powering the remote cabin in the woods, pumping water to life sustaining crops, or mowing your lawn if gas ever hits $5 a gallon. However, for me one of the most exciting aspects of this project is the potential to increase the quality of life of the disenfranchised, the forgotten people of war torn countries, those living in poverty in a far away villages. Those who are a world apart removed from my aggravation when "my seat" is taken at the local coffee shop. Away from my First World Problems. I have friends who go to the far corners of the world to teach indigenous peoples new low impact, high yield environmentally friendly framing techniques. I want another carbon neutral tool for them to use.

I've included a video here to show you my raw unedited first run. The audio and video quality are not great - but you can share my "hey cool it works" moment.

Step 1: Wood Gasification As Fuel Is Old Technology

Picture of Wood Gasification As Fuel Is  Old Technology

The science and history:
Caution I'm not a physicist but I play one on the internet.

Wood gas, syngas, gasification, producer gas. All words that describe the same idea. Turning some sort of organic biomass in to a harnessable useable fuel source.

The general idea: Biomass, if burned in an oxygen low (controlled) environment will produce (mainly) hydrogen, carbon monoxide, carbon dioxide, tars and bio crude. Laymen's terms: If you burn wood the right way you get flammable smoke! That gives a new meaning to the term smoke bomb...

The roots of gasification run deep into the history of industrial man. The flammable vapors were piped into homes and street lamps in the late 1800's before being replaced by Natural Gas. Wood gas generators were strapped to literally thousands of vehicles and machines across Europe during World War II when petroleum based fuels were in extreme demand. Rumors have it that North Korea still uses wood gas as fuel.

One could write a doctoral thesis explaining exactly what is going on. So I'll leave the heavy lifting to the experts. Check out some of this research:

Research, Research, UN Research, Research with fun pictures, Vintage Research, 130 pages of light reading

Step 2: Wood Gasification Vs Charcoal Gasification

Picture of Wood Gasification Vs Charcoal Gasification

There are a lot of wood or bio-mass gasifiers plans out there. They span the range from backyard hack jobs to shiny massive industrial commercial units. Even FEMA has plans for you to build your own. This is probably my favorite DIY FEMA build - his video is worth watching.

For me wood gasifiers have a few inherent issues to overcome.

  • DIY wood gasifiers are complicated to build for the average joe and includes a good amount of welding.
  • Commercially available units are awesome but expensive - and not available world wide.
  • Wood gasification produces bio-crude - that if not cycloned, removed, and filtered properly it can enter your engine.

Bio-crude, quite literally a heavy oil or tar, is made by a process called thermal depolymerization. "Under pressure and heat, long chain polymers of hydrogen, oxygen, and carbon decompose into short-chain petroleum hydrocarbons" Burn bio-mass properly and you get oil that can be refined into gasoline just like the crude oil found in the ground. Some people find very creative uses for bio-crude or tar. (There is much talk about algae based bio-crude - keep your eyes out for that!)

Bio-crude is cool unless you are piping it into your engine's carburetor. Then it will just reduce the life of your engine.


The process of making charcoal however has already removed those long chain polymers. So, when you run your gasifier on charcoal - you just produce vapor and no tar. Charcoal is extremely easy to make using two 35 or 55 gallon barrels - but I cheated and prototyped with a bag of store purchased "all natural lump charcoal".

Step 3: Proof of Concept From Scraps

Picture of Proof of Concept From Scraps

I started my gasification journey with a bucket, a paint can, house project scraps and a tool box full of free 2nd hand pipe fittings.

For this style build you will need a few things.

  • metal container with locking lid that has a gasket
  • Filter canister and filter medium. I used a paint can and some foam rubber I found.
  • Scrap metal plates - I used 16ga
  • Pipe fittings - the majority of mine were 3/4 inch black steel pipe. Beware of galvanized.
  • Intake piping - I used pex initially. This was a bad idea.
  • Exhaust gas recirculation piping. Check out Walker 40000 flexible exhaust pipe. It has a 1 inch ID which fits nicely over a 3/4 inch black steel pipe. In stock at most O'Reilly Auto Parts. Sold by the foot.
  • Ball valves. You will need at least one. Two if you use the exhaust gas recirculation. Three if you want a flare off. Four if you want to use a fan motor to start the charcoal fire.
  • High temp RTV. I found a full calk gun tube at O'Reilly Auto Parts for $2 more than the 3oz size.
  • Clamps
  • nuts and bolts
  • Welder or JB Weld epoxy
  • Pipe wrenches
  • Drill
  • Step bit or really huge drill bit
  • Outdoor work space
  • Carbon monoxide detector

Step 4: Generator

Picture of Generator

My father dropped off his low hour RV generator for fuel system repairs. He was a convenient victim to my mad scientist experiment. This is a 1985 Onan 3.0 with just under 300 hours. It has spent its life tucked up under a very cool Toyota based motorhome. It sprung a fuel pump leak. After I resolved his issues it was just calling to me. It was the perfect candidate for a gasification upgrade. The biggest task was leaving the generator so that it would run on gasoline or charcoal gasification.

I rigged up a metal outlet cover as a threaded mounting bracket for my adapter. Basically you need to figure out how to get T fitting on your carb. One side goes to the carb, one to the fresh air intake ball valve and one to the gasification reactor.

The exhaust was also fitted with a T and a ball valve. One side of the exhaust went to the atmosphere while the other side would be plumbed back to the fresh air intake of the reactor. This would provide a path for some of the unburned carbon monoxide to find its way back into the reactor while also acting as a fan to the flame. Smarter people than me say this is a helpful feature. I've seen these gasifiers run both ways. I think I had a flaw in my return line design.

Step 5: Reactor

Picture of Reactor

The reactor was easy to build. I will say that my air inlet pipe was too low. Please put yours at least 2 inches up from the bottom of the bucket.

These are the steps I made up to build the reactor.

  • Cut 3 equal sized pieces of 16 ga metal. One for the exhaust side, two for the inlet side.
  • Bend the two inlet pieces of metal to the general curve of the bucket. One will go on the outside and one inside for support.
  • Vice both inlet pieces of metal and drill holes in each corner. Clamping each hole with a bolt before moving to the next.
  • Drill holes and bolt both to the bucket. One inside, one outside.
  • Drill a pilot hole for the air inlet pipe through both plates and the bucket.
  • Use a setpper bit drill a hole just large enough for your inlet pipe. Check fit often. Drill through both plates and bucket.
  • Place inlet pipe into bucket so that it fits more than 1/3 but less than 1/2 way into the bucket. I used a screw on stainless fitting on the end of my pipe. It was cut to length and the stainless stands up to the heat better than black iron pipe. Weld inlet pipe into place. (*edit - not stainless. See the fail photos at the end!*)
  • Remove both plates.
  • Put a generous amount of high temp RTV between the outside plate and the bucket. I also put RTV around the weld for good measure.
  • Bolt both plates to bucket.

    Reactor Top
  • Weld 3/4 inch fitting on to the 3rd piece of (unbent) metal.
  • Drill out hole on underside with stepper bit.
  • Drill a hole in each corner
  • Place on bucket lid and drill outside corner holes - securing with a bolt after each hole is made.
  • Drill center hole out after top plate is bolted to the bucket lid.
  • Remove bolts and plate noting the orientation to ensure proper fit. I made an x with a sharpie on the plate and the lid.
  • Put a generous amount of high temp RTV on the underside of the top plate. Bolt to bucket lid.

Let the RTV cure for 24 hours.

Step 6: Filter

Picture of Filter

Charcoal gasifiers are considered updraft gasifiers. Meaning the air is brought in form the bottom of the reactor, burned and the escaping gases are vented through the media (unburned charcoal) and out the top of the reactor. Charcoal is also extremely dusty. Dust particles can hitch a ride on the outbound gases and find its way into your engine. The dust can be stopped with a simple filter.

In this case I used a paint can, two bulk head unions (that I found in that box of parts) and some packing foam I found at work that was getting tossed.

I cut holes in the top and bottom of the paint can for the unions. I added RTV for good measure even though it had a hefty gasket.

The foam was cut into circles and smushed in to the paint can.

Step 7: Charcol

Picture of Charcol

Charcoal needs to be all natural "lump". Hard wood is preferred but softwood will work - it will just burn out faster. You can't use the pressed, chemically treated "ez" light.

You can buy a bag for testing purposes, but I would highly recommend making your own if you want to do this for more than just an experiment.

Charcoal pieces should be more than 1/8 inch but smaller than 3/4 inch. As I understand it this will maximize your air flow while providing carbon dioxide scrubbing goodness.

Step 8: First Run - Smoke Em' If You Got Em'

Picture of First Run - Smoke Em' If You Got Em'

I really had no idea what to expect. My 30 year old generator was only started once in the past 15 years. It was cold and raining but I was very impatient. I had to know if this thing worked.


I took a lit propane torch and placed it on the tip of the air inlet on the reactor and let it sit there. I closed the fresh air intake ball valve and hit the electric starter on the generator.

The suction of the engine pulled the flame of the torch into the reactor lighting the charcoal. Shortly I had a very hot fire burning which produced a good amount of gas. I sprayed the air intake with a hit of starter fluid to help the process along. Did I mention it was cold and raining?

I continued to crank the engine while adjusting the ball valve on the carb fresh air intake. I finally found the right mixture to allow the engine to run by itself. I was successfully able to run a reciprocating saw off my outlet. After about 15 min I shut it down because I had too many leaks.

Gary says he gets about 30 min from 1 gal of charcoal on a 5 hp engine. I have no clue what horsepower this engine was but I burned very little in my first 15 min run (or subsequent runs).

On that note - please be careful. These gases are dangerous in under the right conditions. Carbon monoxide poisoning can kill you if you are exposed long enough. Carbon monoxide (CO) will attach it self to the oxygen molecules in your blood which leads to poor oxygen absorption resulting in organ failure. Failure to operate a device like this in a poorly ventilated area could bring permanent personal injury or death.

Step 9: 2.0 Revisions

Picture of 2.0 Revisions

Version 1.0 was a complete off the wall proof of concept that worked - but it leaked.

Version 2.0 saw a few upgrades.
Carb adapter plate. I tapped a 3/16 piece of flat steel with a 3/4 inch pipe thread and two bolt holes. Utilizing the paper gasket I already cut this stopped all the leaks at the carb from plate flex. I attached the other bracket for good measure to keep the weight of the iron pipe from pulling down on the carb.

I also removed the pex pipe. That was a bad idea. It melted at the bucket and I did not have any pex clamps on it. In an effort to save a few bucks I just removed the exhaust gas return line and put it on the intake side. I was very fortunate the 1 inch inside diameter pipe fits very tightly over a 3/4 inch black iron pipe. If you turn it one the flexible line loosens enough to slip over the pipe fitting - a gentle twist the other way and it locks down like a Chinese finger trap. Exhaust style u bolt clamps would be recommended.

No more leaks!

Step 10: Pop a Cap

Picture of Pop a Cap

Combustion needs three things: Air, Fuel, Ignition. (A special thank you Mr. McNeese in my 1st year of high school auto shop class- see I was not completely tuned out!)

A charcoal gasifer has plenty of heat (ignition) and fuel (charcoal) so the only way to put it out is to remove the air from the environment. This is easily done with metal caps or valves.

I caped and left a very hot reactor over night and the next morning it was cool to the touch and not smoking.

Step 11: Opportunities for Improvement

Picture of Opportunities for Improvement

Compression and storage
All results are data and not all of our hypothesis are correct. I theorized I could compress it, store it in a propane tank and burn it on an outdoor burner. (Think grill, turkey fryer, stove or eventually Coleman lantern). I successfully compressed the gas I produced but I was not able to light it in said stove. I think that if would light in my engine - it would light by itself. I blame my cheap leaking Harbor Freight 12v compressor. I'm not sure it had the ability to draw the volume needed to stoke the fire properly. I would very much like to try this with a larger compressor and see how it does.

Materials and design
This fire was HOT! I though I had a piece of stainless that I cut to length for my fresh air intake. It was actually some sort of cheap shiny chrome looking metal. It melted into large blobs in the bottom of my bucket. Cool - but not working as intended. I would also move my intake pipe up 2 inches from the bottom of the bucket to allow for a larger reaction zone and ash bed.


Prototyping lab

This is my dad's generator. He is coming by tomorrow and I'll have to return it. If I continue to pursue this further I would like to build a rapid prototyping lab. I have a 1971 John Deere Kohler motor with electric start and a bad carb sitting in my workshop. I think mounting this on a cart with a battery would be advantageous. I would like to find a more universal platform that would allow for the utilization of different implements other than just a generator. Belt driven water pump, hydraulic pump, fan, alternator etc.

Charcoal production and refinement
I don't have a charcoal production and processing set up at my house. I can see a real potential for me to utilize a charcoal gasifier. I already burn wood for heat so I have it on my property. I just need a few barrels and a way to properly screen charcoal sizes. Gary Gilmore from PA has a few videos on his awesome setup.

Comments

EVENTUALLY A GREAT JOB!!!!

CONGRATS!!!!

cflorer (author)2016-04-15

When it comes to material, if it burns or rots, you can make fuel from it. I was part of a project where we generated 1 megawatt of power from human waste (poop power). We were also looking at a large scale municipal waste project that would make power from construction wood waste, and yard waste.

RidwanO1 (author)cflorer2016-10-12

Please i want to know how to generate power from poop, from organic waste and i have abundant palm kernel shell around locally.. Can even supply anywhere in the world, my whatsapp/wechat 2347060727672

cflorer (author)RidwanO12016-10-12

http://www.motherearthnews.com/renewable-energy/methane-digester-for-electricity-zmaz70mjzkin

billbillt (author)2016-05-22

This is great to see!.. A few things I remember from reading about this in the past is:

Less HP output from the engine... Wood gas has less btu's available..

The engine needs to be taken down(yearly?) to clean the "sap" out that comes from the wood..

All of this is really just a minor inconvenience when getting free fuel..

heathbar64 (author)2016-04-15

Do you participate on the drive on wood forums? If not you really should. Gary is a member there, and a lot of other really smart and helpful people.

Rusznic (author)2016-04-15

I'm just commenting on the video - it is very hard to understand what you are saying. It is so noisy it is better to dub over the video because we can't hear much!

Other than that good work mate! I've been looking into alternative energy generation for some time now.

Skilltagz (author)2016-04-12

Quick note about CO poisoning, its doesn't bind to the O2, it binds to the oxygen receptor site on the alpha/beta-hemoglobin in your red blood cells, and doesn't detach as easily as O2 and CO2, which is what prevents your tissues from getting oxygen. Great 'ible :)

Rusznic (author)Skilltagz2016-04-15

You are right here!

BruceD20 (author)2016-04-12

After following this type of subject for years- I don't know why I never made the obvious and plain connection to just using charcoal. Wood gas on a large scale can be a real hassle with the filtering, cooling and removal of tar and gook created by raw green biomass. This way you benefit from several uses of the same source materials for heating and whatever, then using the charcoal in the gasifier. I have also found on Google Books that several old 1900's book on Town Gas and Gasification can be downloaded and are a written in plain simple terms. These books allow us to rediscover what has been used in times past to have a comfortable living with simple, manageable tech.

Try these titles- (look to the right for the Gear Icon- Many can be downloaded in PDF!)

https://books.google.com/books?id=qb5LAAAAIAAJ&pg=...

Also- go to Google Books and search for "Producer Gas" It will really open your eyes to old tech. Many of these great books can be downloaded as well!

Thanks again!

FernandaH (author)2016-04-08

Sadly even coal is expensive in the rural areas of South Africa. They turn to Paraffin for a cheaper fuel to burn but it doesn't always help. A friend of mine showed me a rocket-geyser for hot water, it was amazing how much hot water you can get from just a cup of burning paraffin. But burning coal or wood has serious complications not only for the people with health issues (you have to see what it looks like when everyone in a camp burns wood on a cold winter evening) but also for the the environment.

David the R (author)FernandaH2016-04-08

Using a woodgas generator eliminates much of the problems caused by open burning wood in an open fire. The vehicles above are using wood, not charcoal.

UnclTodd (author)2016-04-08

I wish I had kept all those back issues of Mother Earth News from the 1970's and '80's... I remember a few feature articles about "hands-on" Gasogen production and use!

David the R (author)UnclTodd2016-04-08

Go to their website, the 1981 plans are still there.

Type woodgas in the search...

Jack Rodgers (author)2016-04-07

Interesting but impractical on a global or even state wide scale. Charcoal comes from burning trees. Go to Haiti and see how the poor natives cut down all the trees to cook. Or Oklahoma City where the ancestors cut down all the trees... etc.

sogoesme (author)Jack Rodgers2016-04-07

Syngas producing systems can use most any biomass not just charcoal, including waste products from farming/food production for example, straw or shrub, quick growing willow, gasification systems are extremely practical, look at is as a form of solar power, nature also lets us store that energy (biomass) for when we need it, there will always be waste or quick growing biomass so there will always be gasification.

loachridge (author)2016-04-07

Great work on re-working history.

For those who think "impractical" or the like. I have a 23 foot diameter 1500 degree gasifier at work running a high pressure boiler for our steam turbine to generate the electric for the campus.

Oh, yeah. It was built by government. To lower our carbon footprint.

SHOE0007 (author)2016-04-07

Interesting project you actually generated gasses from the charcoal.

Wynfordeagle (author)2016-04-07

"Failure to operate a device like this in a poorly ventilated area could bring permanent personal injury or death."

You may want to re-word that. Your device must only be operated out of doors where there is very good ventilation. Operating it in closed spaces will cause the serious problems you mention.

I would take that even farther. I read a very interesting white paper discussing the carbon monoxide buildup of an engine operating at 10ft vs 20ft away from your house.

Farmer Bean (author)2016-04-07

Any updates?

dbrooks-1 (author)2015-02-10

This is undoubtedly cool, but I'm wondering what you mean by carbon-neutral. If you mean that it doesn't need fossil fuel input, I agree, but if you mean that it wouldn't add greenhouse gases to the atmosphere, I'd have to strongly disagree. The sad truth is that the process of making charcoal gives off disproportionately large amounts of CO2.

I love the good intention behind this project, but it would need to be paired with an initiative to upgrade charcoal-making facilities (i.e. clean charcoal kilns). Or you could try to use biochar instead of traditional charcoal.

Man Up (author)dbrooks-12016-04-07

It is carbon neutral because the carbon released in any biomass fuel was originally absorbed from the atmosphere. Plants absorb gaseous CO2 and combine it with water to form carbohydrates. The energy they use to do this comes from the sun.

Biofuels are actually carbon fixating - when you burn biomass, then biochar is the unburnt byproduct. It's 99% pure carbon. That biochar is often used to amend the soil. So in other words, biofuel use will have a net fixating effect is used in mass.

heathbar64 (author)dbrooks-12015-02-10

What make this carbon neutral is that the wood will release the same carbon into the air when it decay's on the ground as it does if we accelerate the process.

yrralguthrie (author)heathbar642015-02-10

If I lay a log down on the ground and let it decay, it may be gone in a couple of years. If I cut it up and burn it, it may be gone in a day. More Carbon in the air every day wood is burned. Wood is not carbon neutral when time is considered. If the log you burn today would have taken 1000 days to decay then there is 1000 times more carbon in the air today than if you left the log on the ground. Also the carbon from the decaying log is used by the organism that cause the decay, it is not released into the air. So burning wood actually releases many times, 1000, the amount of carbon into the air than the decaying log. Burning biofuel to heat a home not ecologically sound.

AmosP3 (author)yrralguthrie2016-01-03

Yeah... No. You are mistaken, I'm afraid. Combustion of the products of gasification (at sufficiently high temperatures) creates mostly carbon and water, as someone pointed out above. Carbon is super duper stable in elemental form and not a problem for the greenhouse effect.

On the other hand, methane and CO2 from rotting wood, are big drivers of the effect. In sum, gasifying and combusting wood is not only carbon neutral, it would likely sequester large amounts of carbon in stable elemental form and lead to a reduction of greenhouse gases, ceteris paribus.

dbrooks-1 (author)yrralguthrie2015-02-11

That's a good summary of what I read yesterday when I was confirming my belief that this wasn't a climate change panacea. And we haven't even acknowledged the way that incomplete combustion of wood--alluded to below in mention of CO production--can contribute to ground level pollutants like smog. Or the way that charcoal production is a major cause of deforestation in countries that use a lot of charcoal. Unless that wood is harvested renewably, which it very rarely is in rapidly developing parts of the world (e.g. Brazil) because renewable seems like a luxury, charcoal production contributes significantly to the destruction of our much-needed carbon sinks.

That said, there are some well-supported arguments for clean charcoal or biochar, made from renewably harvested bio-stock, having potential to be a significant net positive for climate change. It's just much more complex than people might guess.

stresser (author)dbrooks-12015-02-16

That is mostly incorrect.

Carbon neutral simply means it does not add to the total load of CO2 in the eco system. Since ALL the CO2 in a tree, came from the atmosphere in the first place, none is being added to the ecosystem. The CO2 in fossil fuels are not part of the ecosystem, and therefore burning them adds to the total amount of CO2.


The time frame of release is irrelevant. Carbon neutral means that as long as we keep the mass of trees stable, or ideally increasing, the total amount of CO2 tied up in trees will balance out that which is re released into the atmosphere. If we increase the total mass of CO2 being consumed by vegetation, if fossil fuels were abandoned, total CO2 in the atmosphere would drop regardless of how much vegetation was burnt.

The problem with this, is that our total mass of of vegetation is decreasing.

namora (author)2016-04-07

This is likely one of the dirtiest fuel sources possible if you discount the Tar Sands effort. The production of charcoal by incomplete combustion is a huge producer of carbon monoxide alone. It is an interesting project but no combustion energy source can be anything but a major source of atmospheric carbon. Sorry, but do the science.

Man Up (author)namora2016-04-07

So here is the science: this is a carbon fuel that is locally sourced, so there is a much lower embodied energy than fuels transported from abroad. People using biomass generators are literally picking up sticks in their own yard. And the carbon content of the fuel is captured by plants from the atmosphere, so this is at least carbon neutral. This is the most environmentally friendly form of combustion energy out there. The only way to generate energy more cleanly is to go solar. And most people I know who are using biomass generators are doing so to augment PVA power sources in off-grid applications.

mstroven (author)namora2016-04-07

so what? People in poverty and in war-torn countries don't give two shakes for their "carbon footprint". Nor - for that matter - do I.

BryanB7 (author)2016-04-07

I am going to play with this. I have rebuilt or modified many devices to not put out any or very low carbon . All have passed the emissions test .One of my friends has a wood gasifier he will help me with this project. Thank you of posting this emagen the posabilatys

михат (author)2016-04-07

usually put 2 filter and cooled manifold, so the eye is not too hot

ValentinoM (author)2015-03-26

wow! you know, in Italy during Fascism, when the country was embargoed and couldn't import enough oil, people started running vehicles with charcoal and wood. They used these funny modifications (an equipment called "gassogeno" aka wood gas generator). I always found this technology fascinating!

kel999 (author)2015-03-16

great!!

John_the_Builder (author)2015-02-10

Cool, I learned something new. I would have thought that the process of heating Wood into Charcoal would also burn off most of the Gasification potential. So using Charcoal rather than wood to gasify, is actually cleaner?

quirxi (author)John_the_Builder2015-02-10

Hmm, I also thought that characoal does not gasify very much compared too plain wood. In fact I always thought that heating up wood in the absence of oxygen till all vapor and gas left the wood is the way to make charcoal!? Could anybody clarifiy this ?

GordieGii (author)quirxi2015-02-21

Both correct. Turning wood into charcoal removes pretty much all the hydrogen and oxygen leaving behind pure carbon (plus ash which is basically salt and lye) behind. The terms gasification and syngas are being used somewhat loosely. Syngas or synthesis gas usually refers to a mixture of CO and hydrogen, produced by passing steam through a hot coal bed (possibly with a little air to keep it hot, excuse my ignorance) which is the stuff that used to kill people if they left an unlit stove on by carbon monoxide poisoning. Gasification usually refers to driving off the hydrogen, oxygen and some of the carbon in the former of hydrocarbons and carbohydrates from biomass, leaving behind charcoal. In this case gasification is used to mean the production of relative hydrogen free Syngas. In the combustion chamber it acts like a mixture of CO2 and "carbon gas" (2 CO + 1 O2 = 2 CO2 + heat)

GordieGii (author)quirxi2015-02-10

You are correct, sir!

You make charcoal and wood-gas by heating wood in the absence of oxygen and when all the wood-gas has evaporated off you are left with charcoal.

Charcoal does not gassify. It produces carbon monoxide. (Not vapor, an actual gas.) Which is combustible.

In theory, once you got the CO (carbon monoxide) generator and the ICE (internal combustion engine) running you should be able feed the exhaust back to the CO generator and have an almost closed loop. The oxygen enters at the carburetor, in the ICE the oxygen and CO turn into CO2 (carbon Dioxide) then the CO2 exhaust goes back into CO generator where one CO2 molecule and one carbon atom turn into two CO molecules which then go back to the carburetor. ...and round and round.

Of course, in practice, you have to let air in at the carburetor so the volume in the system would increase indefinitely so you have to let some of the exhaust escape and lose some CO2 so you have to let a little air in at the CO generator to make up for the loss.

SeanP3 (author)GordieGii2015-02-18

At first, I read the "closed loop" as perpetual, but obviously noone is claiming that, nor should they.

One thing about this system that I don't think I saw mentioned is the energy required for converting CO2 to CO.

The super hot coal bed has enough energy to convert CO2 into CO, which slightly reduces the amount of heat in the coal bed.

In theory, you could _completely_ close the loop for some finite amount of time ... pipe the CO2 back through the bed, convert it to CO, reduce the residual heat energy in the coal bed, repeat.

In practice, feeding in more fresh air (O2, specifically) burns more Carbon into CO2, which also produces heat and raises the temp of the coal bed.

Some perfect mixture of closing the loop and letting in just enough fresh air, and you should be able to tweak the efficiency of the system. You only need to "burn" the coal fast enough to keep the heat high enough to produce the amount of CO that the generator can use.

Going out on the "crazy limb" for a minute ... if you're in a cold climate where heat is needed, imagine building a TLUD wood gasifier to heat your house while producing the charcoal, with a system like this that can be engaged off the hot coal bed after the wood gas phase is over. In other words, heat your house first, then charge your batteries with the excess heat from the coal bed.

Interesting thoughts all around, thanks for the video too!

Sean P

quirxi (author)GordieGii2015-02-13

Cool, thank you for the explanation. Now I understand how it works! Thirst I thought that perhaps H2 is produced by putting water vapor over the coal.

I think its called water gas: C + H2O --> CO + H2

see: http://en.wikipedia.org/wiki/Water_gas

yrralguthrie (author)GordieGii2015-02-10

Say What...?

theo67 (author)2015-02-15

Sound like it is what was called "Producer Gas". We used to learn about this in school science. Producer gas contraptions were fitted to cars during WW2 due to gasoline being in short supply. I recall seeing some of these with a smoking chimney attached to the rear of the car. The driver carried a bag of coke or charcoal and stopped occasionally to stoke up the burner. There were also reports of them exploding as well.

bgoldberg1 (author)2015-02-14

By choosing to use charcoal as fuel, instead of wood, you lose a significant amount of energy which would otherwise go to producing useable power. This is because the act of turning wood into charcoal throws away a significant fraction of the chemical energy in the wood.

Also, gas made from charcoal has a larger proportion of carbon monoxide, and less hydrogen, than wood gas. Since carbon monoxide will spontaneously decompose into carbon dioxide and carbon dust, when compressed, it will lose more energy than wood gas would, if you choose to compress it for storage.

My advice is to not bother storing the gas, but produce it as you need it. A storage tank for the gas wouldn't be much lighter than the gasifier itself, and charcoal (or wood) will be safer to keep stored than compressed gas anyway.

Also, consider going for wood instead of charcoal. All Powers Labs has designed some very clever gasifiers which recycle waste heat from the engine, in a way that results in a surprisingly higher conversion rate of solid chemical energy (in the wood) into gaseous chemical energy (fuel gas). This results in higher efficiency.

hjartland (author)2015-02-13

This is a very cool idea. As for the carbon neutral part. It has a ways to go. That said it could do a lot for remote villages who lack petroleum. Often times they have all kinds of bio-mass to make into char-mass.

As for the storage of compressed gasses. You may want to put a heating and expansion chamber inline between the feeder tank and the carburetor. The state of the gasses coming from the reactor had a lot of heat and HVLP (high volume-low pressure). The right kind of chamber could defuse the pressure from the tank and make it more of a LPHV low pressure-high volume. At the same time you could introduce heat.

Anyway, just a thought or two. Keep innovating. Detractor are never happy until it is completely refined. Use their critiques to identify problems and make it better.

Nice job!

brewgoat (author)2015-02-12

Great instructable. Will be trying this very soon. I would add one comment on it being CO2 neutral. Wood in its raw form is a kind of carbon sink. Even if it does decay not all of the carbon gets released back into the atmosphere as many other things like other plants and animals would have used some of the carbon. It's not a 1 to 1 transfer from the wood to the atmosphere.

jimkeel (author)2015-02-12

Be EXTREMELY cautious while attempting to compress a combustible gas! Spend lots of time on research (ideal gas laws) and safety (the container and compressor could easily explode if the gas ignites during compression).
Second, research the regulator used on the grill (or whatever device) you are attempting to operate with the compressed gas. It should have a flow rate, and an output pressure, matched to the fuel it was designed for. Learning more about the properties of gassified charcoal would provide some good information to guestimate the adjustments needed.

Above all: BE CAREFUL WITH COMPRESSED GAS! Even scuba cylinders explode when filled incorrectly with air, and it is almost always a tragedy.

stoobers (author)2015-02-10

Hello,

This gas likely won't "compress" as you hope. The primary combustion gas is hydrogen, with CO thrown in there as a consequence of the smoldering charcoal. So it won't really "liquify" like propane will, and there won't be much in the tank.

I have never seen anyone do this on such a small scale. I wouldn't have thought it possible, so I am impressed.

This is pretty much a mini version of the fema woodgas article, except with charcoal instead of wood.

Is there any chance you will do some experiments on how long you can keep the tool doing physical work (using a pumping water, etc) to see how much power you make and for how long? Then you can get a horse power hour per pound of charcoal rating for your rig. I don't think that has ever been calculated, and would be worth publishing somewhere.

I read gasoline works out to be 14 horse power hour per gallon (at 7 pounds-ish per gallon) so about 2 horse power hour per pound of gasoline. Do you think your rig is close to that?

More Cowbell (author)stoobers2015-02-10

Hey Stoobers,
This was definitely a proof of concept experiment for me. I see a lot of things floating across the interwebs and I'm skeptical. (I understand the irony - because this build too is on the internet) This was the original video I ran across that made me want to build a charcoal gasifier. By the looks of it he has a much better space to produce and process charcoal. The generator is about to ship out. Camping season is almost here down in the Mid Atlantic/South East and my retired parents are eager to get their 4cyl YoterHome on the road.

I'm still not convinced I can't compress wood gas - but I'm stubbon. I think that if I can get a better flare off the reactor I'll be able to store it. We'll see!

stoobers (author)More Cowbell2015-02-11

I am positive you can compress the gas.
The issue is liquifying the gas.
Since it is H2, it won't really liquify, so if you quadrupled the pressure, you would have 4x the gas, which is pretty high for a decertified propane tank - think of how thick a helium bottle is, and that is what you might need to make the compression viable.
That may be a lot of work for just a little more gas.
You likely would be better off getting a big air tight bladder (think hindenburg, or a weather balloon) and filling it up.
Some of the books on producer gas show a big air bladder on the roof a bus to hold the gas, so it can store up the gas to make the hills.
The CO mixed in is heavy, so it won't likely float away.
It is ok if the gas "breaks down", as it would break down into other things that are inflammable.

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