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The Gasifier Experimenters Kit (aka: the Lego gasifier)

The Gasifier Experimenters Kit (GEK) offers beginners through experts an easy way build, compare and customize a wide variety of gasifier reactor types and configurations. Whether you're a DIY enthusiast or a university researcher, the GEK will get you over the starting hurdles of biomass gasification, and on to the more rewarding work of refining specific architectures, testing fuels, and making power.

The GEK kit is designed in a modular fashion which allows for easy switching between common reactor types and operating regimes. Each "reactor type" is a separate assembly that bolts into a common "gas cowling and ash handling" base. See here for the full list of planned GEK reactors. Within each reactor type, relevant variables are easily adjusted and sub-assemblies are simply replaced via standardized "bolt to" flanges.

The result is a Lego system of gasification- a motivated and flexible building system enabling you to run, compare and share results over a wide range of architectures and commonly discussed --but rarely implemented-- "expert configurations".

Getting Started in Downdraft Gasification

The default reactor offered for the GEK system is a nozzle and constriction (Imbert type) downdraft reactor. An Imbert downdraft is the usual starting point for generating low tar wood gas to power internal combustion engines. The GEK version combines all common Imbert type variations into a single configurable reactor, with easy adjustability of all critical dimensions. Here's what it can do:

  • variable combustion / reduction zone size and shape (tube, bell, inverted V, hourglass)
  • variable air nozzle position and size
  • air preheating (or lack there of)
  • active tar recycling into incoming air
  • variable air injection architecture (air from top, bottom, or side annular ring)
  • "monorator" type condensing hopper
  • rotary grates/stirrer additions

The GEK Imbert reactor is delivered with a default configuration known to produce clean syngas when operated by a knowledgeable enthusiast. This default configuration will run 5-20hp engines. Other GEK configurations will support up to 50hp engines. (typical disclaimers apply, given the variability of fuels and human operators)


To be clear, the GEK is not a turnkey wood gasification unit. It does not guarantee 24/7 hands free operation right out of the box. Such is usually a dubious claim anyways, given the fuel sensitivity and use variability of all small-scale gasifiers. What the GEK does promise is a highly motivated building and configuration system, enabling you to build, run and test all the best ideas in small scale biomass gasfication. In the hands of a knowledgable operator, the GEK will produce excellent results. And once you do achieve your performance goals, the GEK manufacturing scenario gives you an easy to way to set up formal manufacturing of your solution in your local area.

GEK Community

The expertise to support the GEK is the responsibility and opportunity of its community of users. We encourage the growth of specific set up suggestions, use reports, and quantative data via the project wiki and general community collaboration. A basic instrumentation set comes with the full GEK kit, so you will be able to share quantative data with others- mabye even help advance the general state of gasification.

The GEK design partculars and manufacturing technique are open source and well documented (see the downloads page for details). You are welcome to use this common base "operating system" to build new "applications", "widgits" or other customizations- whether open source or proprietary. Or to put it in gearhead terms, the GEK is the proposed "small block chevy" of gasification. It is now your job to build the better cams, carbs, cranks, and manifolds to make it go faster. . .

We invite you to join the GEK community of collaborative science and open source engineering.

Questions? Contact: gek_at_allpowerlabs_dot_org

downdraft reactor rings