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Page history last edited by jim mason 6 years ago



APL began as an experiment in collaborative science and open source engineering.  In the 8 years since we started working with gasification through the GEK Project, APL has evolved into a small-scale biomass electrical generator manufacturer. We currently offer the low-cost, open-skid Power Pallet PP20, and the updated GEK Gasifier Kit. We are actively developing the clean and quiet Power Cube PC20, and are nearing completion of our 150 kW PT150 Powertainer beta prototype. Despite the patented and proprietary nature of our newest and most optimized gasifier designs and our success in building a large installed base of machines helping to solve the problems of the waste management, energy access and climate change, we are still working with GEK participants and gasifier enthusiasts to openly advance the science of gasification, as well as the engineering solutions to implement it meaningfully for users today and into the future and around the world.


With this wiki we are trying to curate a comprehensive and growing knowledge base of everything we have learned about gasification and the resources we have uncovered in our work.  Here you will find detailed GEK gasifier building plans, gasifier configuration and operating tips, "how to" instructions for converting engines to wood gas, raw science, practical engineering, and many other topics of interest for Power Pallet users and gasifier geeks.  All topics are open for any contributions or edits you would like to offer. 


We are archiving our previous GEKforum, but will continue to host general discussion and debate about these topics in a new venue currently under design.  General information about the APL and our products can be found on the main APL site.  To get biweekly email updates on the project, click here and fill in the blanks.   






GEK How to:


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Gasifiers in Operation


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GEK Improvements, Add-ons and Customizations 


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Biomass Fuels: Their Characteristics and Prepartions


click here for full list




Practical Engineering: Solutions that Work

click here for full list




Raw Science: Drying, Pyrolysis, Combustion and Reduction


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Instrumentation, Testing and Electronic Automation


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General Resources


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Old GEK News

Comments (33)

quirxi said

at 2:10 am on Jan 20, 2009

Is there already an updraft version of the GEK ?
I would need one for a little foundry ...

Ken Boak said

at 4:37 pm on Jan 21, 2009

I've put some pictures of my GEK and first firing onto Flikr


quirxi said

at 1:20 am on Jan 22, 2009

Cool pictures ! How did the woodchip auger do ?

Ken Boak said

at 9:09 am on Jan 24, 2009

We tested the auger a few weeks back. It seems to work OK with the trashy wood chip fuel I'm experimenting with. The geared motor makes one revolution per minute and is rated at about 300W.


(account deleted) said

at 8:30 pm on Jan 28, 2009

Congrdulations guys. By my count you have now spread more gasifiers across the planet into more hands than any other single effort in the last 50 years.

Steve Unruh

Ken Boak said

at 2:56 am on Jan 29, 2009

Jim - regarding the tar fence, I think I could probably knock one up myself.

I'd take some mild steel sheet 24" long by 6 or 8 inches wide. This could be rolled into a 7" diameter tube (circumference 22" approx) - so that it allows the nozzles to protrude through it by 0.5" . This would allow caps to be screwed on for nozzle size reduction if needed.

By drilling 6 rather than 5 equi-spaced holes for the nozzles, it would allow the fence tube to pass twice over one nozzle - effectively providing an overlap seam and helping to secure it in place.

The holes for the nozzles would have to be spaced every 4.4", starting 1" in from the end of the 24" length. This will give a 1" overlap seam - which could be sealed with weatherstrip and pop-rivetted - for the non welders amongst us. The nozzles could also be sealed with weatherstrip.


(account deleted) said

at 1:33 pm on Jan 29, 2009

Hello Ken Bock - as a fellow Lister type owner I think a simple steel rod from the engine to the reactor body would provide more than enough shake. My Experimenters kit is still in production but a friend has his and Lister type engine at the same stage as yours. I would propose for initial proof testing we use power sawn up hatchet chunked (to get the nails out) shipping pallet wood as a standardized fuel. We will all of course have to modify configurations later to optimize for our own site specific fuels. As a mechanic I think if your jets were all turned 90 degrees away from center a 6"(150mm) tube could be inserted and the air nozzles turned into your holes. Stainless 6"(150mm) wood stove pipe is common here.
Steve Unruh

Ken Boak said

at 2:13 am on Jan 30, 2009


Agreed - a steel bar from the rocker cover bolt on the Lister to the GEK will certainly shake it.

Good idea using a standard stove pipe flue section for the tar fence - sometimes you find these at scrap yards.

I am working on an idea of using the hot Lister exhaust to dry and torrefy the woodchip fuel. There is significant heat energy in the exhaust gases, and the torrified woodchips will absorb the soot and aromas of burning vegetable oil, as well as providing sound-deadening.

I have a stainless steel exhaust gas (to water) heat exchanger which I might try as the gas cooler, to remove the condensate.

Later today I will strip down the GEK to analyse the first 3 runs and see the ash content, and the size and shape of the char particles remaining in the reduction cone.


Ken Boak said

at 2:23 am on Jan 30, 2009

GEK Users - please get in touch!

Jim's recent map showed about 45 GEKs shipped world wide.

It would be useful to have contact details of the new users and some idea of the proposed application.

AllPowerLabs cannot give these out - so may I invite any interested users to leave a comment, with their name, location, and whether part of an organisation or a private user. Full address or email details are not required if you wish to keep these private.

Please indicate your intentions with the GEK, eg research, mobile use, stationary use and the fuel type you intend to use.



(account deleted) said

at 3:01 pm on Jan 30, 2009

Hm-m-m. OK, I'm too old to be shy anymore. My name is Steve Unruh. My goal is to successfully produce 3kw electricity sustainable off of wood grown and harvested on our 20 acre wood lot. So small stationary power in the 6 hp range. Modern steam was too expensive and too inefficient. Stirling engines, unproven and way too expensive for one off hand built designs. So wood gas in an IC engine. So an Indian produced Lister CS clone as the most flexible/fixable current production test mule. And a Jim Mason Gek as the ONLY system in the world designed down to this low power level. Why 3kw? Because any family can support all of the modern "necessities" except for space heating and cooling on this much power with a daily 45 minute commitment for hand processing wood fuel. My personal wood sources are Douglas fir tree limbs, capishable Hazel nut and Holly tree stems ranging from 1/4" (5mm) to 1" (26mm) diameter.
I have no personal web page. You can if you wish read my Gasification posts at : http;// Lots of research web sites listed there in the posts. And those able will pick up on my mix of Heinlein/Schumacher/M.G.Kains life philosophy.
My Email is:
You can google map my little mountain valley hometown as Yacolt, Washington USA 15 miles south of Mt. Saint Helens and a mountain range west of the Windward folks.

I don't hav

ScubaPost said

at 6:11 pm on Feb 3, 2009

Hey All,

I made a 3D model of the Gek gasifier mounted on the Accord in honor of your recent accomplishment. I hope you like it:

and here's a little concept car I threw together using roughly the same size gasifier to see how a mass produced modern woodgas vehicle might look:

Let me know how you like it! Thanks.

(account deleted) said

at 1:12 pm on Feb 11, 2009

Hello Ken Bock
If you are willing, would you Email me your Email address? Our security protocols are blocking a connection route. I have a couple of Lister/iod questions and comments not related to gasification I'd like to exchange.
Thank you
Steve Unruh

adolf said

at 8:09 am on Feb 13, 2009

hello GEKers,
we've build a open core dowm draf gasifier, not very happy about the resoult we get, too much tar. it is a ricehusk gasifier.
well the point i want to stand is: is there any one trying to make GEK work with agriculture waste material, cause that will be a solution for many people in the work.
i know people working about this in colombia, so coffe, rice husk and coconut shell us primitive fuel opcions could help thousands of people.
if any one is interested in the diseng we get, just email me
some solid edge and pdf are available.
open source, of course.

gary kemp said

at 2:29 am on Mar 4, 2009

hi all in reply to ken boak's post regarding the location of people
well my name is gary kemp and i am currently in the process of getting the parts together to build one of these units (just haveing the steel laser cut) i intend to experement to see if it will run my 10kva static generator out in spain the generator supplements my solar power. this is a really great site and i have learnd a great deal, i had no idea what a pipe nipple was till now still working on the things like 4x3 cast iorn sewer increaser and 4'' ruber jim cap we obviously have these things over here its just working out what they are called in the uk then what they are called in spain
so at the moment i am very much a beginer and to be honest not that green a person but being on a pension now (retired early) the rise in fuel costs have made me seriously look at ways of useing alternative energy, and where i am in spain (near tortosa catalunia) i have plenty of wood as a fuel source and enough land to plant a couple of acres with quick growing poplar as a sustainable fuel source
just one suggestion for the site its got pics of just about everything but its the small parts as well that take a bit of identifiying, from my point of view as a total newcomer to the world of american plumbing. a lot of the bits i have to guess as to what it looks like if there isnt a close up on the photo,so maybe just a photo of one of each of the plumbing parts would help the overseas builders to identify for example a 3/8''black street elbow.
so ken you can add me to the list of builders and my contact detail is
ps has any one used anything different for the ss 3/4'' gas connector as this tube in the uk costs more than everything else put together (would flexible coppertube work)

(account deleted) said

at 12:33 pm on Mar 4, 2009

Hello Gary Kemp
If you go to "main GEK Site" then open picture "gallery" if you look at Jim Masons earlier pictured GEK V0.9 you can see that the SS gas tube could be replaced with rigid pipe and shorter copper flex tubing. Copper will heat the incoming air/cool the out going gas better than stainless but will not be as heat resistant. You would want to use the copper flexes WITHOUT the plastic sleeves on the ends. Metal to metal only. Familiarize your self and use what is available locally. The only thing at all special on the whole design is the reduction tube (3' x 4" cast reducer) and Jim himself and others are now fabricating that part out of rolled welded steel. Show them the pictures and have a local fab shop make it out of 4mm metal. Good Luck Steve Unruh

jim mason said

at 12:53 pm on Mar 4, 2009

"The only thing at all special on the whole design is the reduction tube (3' x 4" cast reducer) and Jim himself and others are now fabricating that part out of rolled welded steel. Show them the pictures and have a local fab shop make it out of 4mm metal. Good Luck Steve Unruh"

we're now making them out of 16awg stainless, not 4mm. i have some pictures of the new ones i'll post soon. i'll include the cut files so you can cut them out and bash them into shape. yes, a roller is nice to make them, but you can also make them with a vise and hammer.

your project sounds impressive gary. tell us if you need anything else. send us some pictures too. we'd love to see what you are doing.


gary kemp said

at 10:35 am on Mar 8, 2009

hi jim and steve thanks for the comments
i have just recived my steel back from the cutting shop and a great job they have made of it watched them cut some with the laser its a really impresive machine.
i supplied them the cad drawings which made the whole process easy so thanks to those who took the time to produce them
however could i just highlight a couple of things that i have just come across when checking the parts againt the drawings to make sure they are all there
on the gas cowling the 4 holes for the ash cover could be shown and a corresponding plate with 4 holes added to match
and on the swirl burner a hole indicated to take the pipe then it could all be cut at the same time, please dont take this a complaint or anything just something i noticed when checking the parts so far very impressed with it all will be able to start the assembly process so as i get back down to spain cant wait to try my hand at welding

jim mason said

at 1:41 pm on Mar 8, 2009

glad your cutting went well gary. cnc cutters are an amazing thing, aren't they?. i find them to be the core tool to enable small scale distributed manufacturing. the gek manufacturing process is premised on this tool, and thus we now have the ability to set up new manufacturing sites simply moving the files to a new machine. a manufacturing plant in a digital folder. we live in an era of such riches.

the cnc table is about $10,000. not cheap, but vastly less than starting a stamp and dye plant, which is how one would do this at large scale. dev world entrepeneurs have suprisingly been one of the main groups interested in the gek, as they see this as a tolerable price point set up local production. individuals are currently pursuing this option in india, thailand, brazil and haiti. nothing going yet, but people are scheming.

as for the missing holes, note that the files on the main gek site are the v1.x files. the instructions and pictures on the wiki are of the v2.x machine. the differences are minor, mostly the change to a full tab and slot system to make the fab fixturing easier. well, the cyclone changed to a rolled cone instead of the welded together fingers. and the lack of bolt holes you found is because previously we welded sewer cleanout fittings over these holes and didn't just use the port plates as we do currently. otherwise, there are no changes to raw dimensions between v1.x and v2.x for all vessels tubes, flange rings and end plates. there is full interchangebility between the v1.x and v2.x geks.

i haven't had time to put us the full v2 set in the formatted manner like the did the v1.x. but here they are two grouped sets. one file for all the flange rings and end plates. and one for all the vessel tubes. the new cyclone is in here too. also, the ash grate and filter mesh, which were not in the v1 drawings.


jim mason said

at 2:09 pm on Mar 8, 2009

link error. here's the correct wiki page for the v2.0 cad drawings

(account deleted) said

at 7:15 am on Apr 12, 2009

JimM. or TomP.
I would suggest you collapse this front page comment section. It looks old stale and dated, If possible the space could be used for an expanded current events or all category recent comments. Actual GEK owner comments here could be transfered to the individual owners pages. You really don't want me trying to fool with this front page. I'm pretty computer disastrous. Regards Steveu,

Joe McDaniel said

at 7:28 pm on Jun 25, 2009

Will a GEK run a diesel engine?

adolf said

at 4:00 am on Jun 26, 2009

hi again.
Joe McDaniel ask:
"will a gek run a diesel engine?"
well, 80% yes 20% no. What do i mean? my personal expirience and what i have read about said that you can easily reduce to a 25% your diesel espenses, but in any case some diesel is need to start de ignition.
in a 20 kW engine we suscess to run with a diesel reduction to 16% but the engine was running only at 15kW.
for more detales send me and email.
i don't to worry the people


Joe McDaniel said

at 6:00 am on Jul 14, 2009

Charcoal for packed bed filter. How do I obtain the charcoal for the packed bed filter? Do I have to make it myself? If so what is the best way to get the proper size?

Sonny Djatnika Sunda Djaja said

at 7:39 pm on Jul 31, 2009

I hope these instructions give advantages for our eatth. Thanks

Joe McDaniel said

at 9:52 am on Aug 6, 2009

Ok, I got everything put together and was ready for my first fireing. I had the charcoal fired up and a real good center glow. So I added my biomass material, chipped dried mesquite. Closed the lid and turned the fan on. My five are intakeds were open. I quickly got a steady stream of smoke into my swirl burner which I had a lit propane torch for the pilot light. I kept waiting and waiting for the gas to ignite. Is it possible that my biomass material was too small? I used a chinese log chipper. I even filtered out all the tiny pieces and removed the dust from my chipped materials but it would note lite off. Please help!

Andrew Schofield said

at 3:30 am on Sep 29, 2009


I am receiving updates on APL's work, as the GEK Wiki is changed. Is there a better mode? Interesting stuff here, my friend!

In the latest change post, I noted measurememt of temperature directly in front of a nozzle is currently made by a thermocouple placed here.
May I suggest this measurement could be made less invasively (disrupting fuel/air flux) by measuring radiation emitted back out one nozzle.
I know the jimbert GEK uses plumbing internal to the reactor, and fitting a sensor here may cook it.

Me doing less precise science, just look into one (of 7) nozzle bore to observe degree of brightness within the hearth. Light-off is effected here also.

Wanting to have a gasifier control unit of some type, perhaps just a low-temp alarm, what available sensor could convert radiation emmitted to a usable signal?

Andy Schofield

Answer Blip said

at 5:53 am on May 9, 2010


Mr Moffitt said

at 11:25 pm on Jul 1, 2010

Great wiki folks, lots to get a newbie to woodgas going.

JR Miller said

at 2:26 am on Jul 26, 2010

Newbie I am a retired American mechanical/electronic/software engineer. I'm in Bago City Negros Occidental Philippines. Am in the process of building several GEK's. I own a rice mill so naturally the rice hull will be my fuel. First GEK will be for Power to a ten kilowatt generator using a toyota 3k four cylinder engine. Second GEK is for a spark converted china diesel twelve hp to run a blower for a forced air rice dryer. Third GEK is for a flare off to create heat for the rice dryer seventeen kw. Last but not least is GEK for spark converted Ford industrial six cylinder diesel to run the rice mill. I am doing the GEK Electronic control design myself along with the software. I spent forty years doing these designs. LOL. Anyone in the Philippines needing help please contact me. or call or text. 0906-558-4630 I have a good friend here that owns a machine shop and is US quality on fabrication a lot of philippine machine shops lack knowledge. And Ruben is low priced.

JR Miller said

at 3:17 am on Jul 26, 2010

See there is a philippine project going on in August this year. Wished I could attend but I have severe spinal damage as the result of a sprint car crash more than twenty years ago and have a hard time traveling. Besides I smoke like a gasifier and drink like a fish and eat meat at every meal so I feel I would impose. LOL So if you come here to visit me in the central philippines expect the local culture. Work hard all day taking smoke breaks, Eat heartly and drink at night to sleep. LOL

JR Miller said

at 3:33 am on Sep 30, 2010

Getting the first unit done. Third world makes things hard. No plasma cutter. Jigsaw on stainless sucks. Also no tig just five sixty forths ss welding rod. Luckily I built race cars for many years And in my old age and spinal damage I can still time the shakes in my hands with the spot spot on thin ss while welding Will post some photos soon doing Hot Tottii with triple hips reactor for burning rice hull. Found a couple mistakes in the version 3 cad drawings. I know the paper work sucks but it makes replication easier.

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