Go deeper
Resources & References
The best books, manuals, forums, videos, and tools the gasification community has produced. Everything here is tried-and-tested by real builders.
Foundational Manuals
The documents every gasifier builder should read before picking up a grinder.
FEMA Gasifier Manual (1989)
The original emergency gasifier document from the Federal Emergency Management Agency. Freely available, battle-tested design, and still the best starting point for beginners.
Gengas — The Swedish Wartime Gasifier Book
Translated from Swedish, this 1950 document covers the engineering of vehicle gasifiers in extraordinary depth. Dense but invaluable for understanding Imbert-style downdraft designs.
FAO Forestry Paper 72 — Wood Gas as Engine Fuel
A thorough technical overview from the Food and Agriculture Organization of the United Nations. Covers design principles, gas quality, and engine integration.
NREL Biomass Gasification Technology Assessment
A modern technical assessment from the National Renewable Energy Laboratory covering gasification chemistry, reactor types, and syngas cleanup.
Communities & Forums
Where active builders share builds, troubleshoot problems, and push the technology forward.
Drive On Wood Forum
The most active English-language gasification community. Thousands of build threads, troubleshooting discussions, and years of accumulated knowledge from experienced operators.
Gasification.com Community
A long-running forum with deep archives covering everything from FEMA builds to advanced Imbert designs and agricultural gasifiers.
Permies — Rocket Stoves & Gasification
The permaculture-focused Permies community has an active gasification subforum with a strong DIY and off-grid angle.
Video Channels & Documentaries
Watching experienced builders work is one of the fastest ways to learn.
Gary Gilmore — All Power Labs
Gary's YouTube channel documents hundreds of hours of real-world gasifier operation, testing, and engineering. His GEK (Gasifier Experimenter's Kit) work is some of the most rigorous open-source gasification engineering available.
Ben Peterson — Wood Gas Videos
Ben has been running wood gas vehicles for decades. His videos cover practical vehicle conversion, fuel preparation, and long-distance driving on syngas.
Viktor Zupancic — Gasifier Builds
Detailed build documentation from a European builder with a focus on clean, well-engineered designs. Excellent for understanding filter and cooling train construction.
Calculators & Design Tools
Online tools to help size your reactor, estimate gas output, and plan your build.
All Power Labs GEK Wiki
The open-source GEK gasifier wiki includes design spreadsheets, throat sizing calculators, and detailed build documentation for the most thoroughly documented open gasifier design.
Imbert Throat Sizing Calculator
A community-maintained spreadsheet for calculating the correct throat diameter, hearth diameter, and nozzle sizing for a downdraft Imbert gasifier based on your target engine power.
Biomass Energy Data Book (ORNL)
Oak Ridge National Laboratory's comprehensive reference for biomass energy content, moisture relationships, and feedstock properties. Essential for fuel selection and sizing calculations.
Books Worth Buying
A short list of print resources that go deeper than anything freely available online.
"Wood Gasification" by Alexis Belonio
A practical engineering guide focused on rice husk and biomass gasification in developing-world contexts. Excellent coverage of updraft designs and agricultural feedstocks.
"Handbook of Biomass Downdraft Gasifier Engine Systems" — Reed & Das
The definitive engineering reference for downdraft gasifier design. Written by researchers at SERI (now NREL). Out of print but available as a free PDF from NREL.
"Small-Scale Biomass Gasifiers for Heat and Power" — Stassen
A World Bank technical paper covering the economics and engineering of small-scale gasification. Particularly useful for understanding system efficiency and cost analysis.
Terminology
Quick glossary
New to gasification? These are the terms you'll encounter most often.
Synthesis gas — the combustible gas mixture (primarily CO, H₂, and CH₄) produced by gasification. Also called producer gas or wood gas.
The upper zone of a downdraft gasifier where biomass is heated in the absence of oxygen, releasing volatile gases and leaving char.
The combustion zone where air is introduced and partial combustion occurs, generating the heat that drives the process.
The char bed below the oxidation zone where CO₂ and H₂O react with hot char to produce CO and H₂ — the useful combustible gases.
The constriction in an Imbert-style downdraft gasifier that concentrates heat and ensures all gas passes through the high-temperature oxidation zone.
Complex organic compounds produced during pyrolysis that condense at lower temperatures. Tar in syngas is the primary cause of engine fouling.
The ratio of actual air supplied to the stoichiometric air required for complete combustion. Gasifiers typically operate at ER 0.2–0.4.
The ratio of the energy content of the syngas produced to the energy content of the fuel consumed. A well-designed downdraft gasifier achieves 70–80% CGE.
The volumetric flow rate of gas through the gasifier per unit of hearth cross-sectional area. A key design parameter for sizing the reactor.
The percentage of water in fuel by weight. Wet basis MC = (water weight / total weight) × 100. Gasifiers require fuel below 20% MC; below 15% is ideal.