Biomass Gasification: Wood Gas as a Fuel Supplement

What Is Wood Gas?

Biomass gasification converts wood, charcoal, or other carbon-based materials into combustible gas through partial combustion in a restricted-oxygen environment. The resulting syngas contains 15–30% hydrogen, 20–30% carbon monoxide, 2–3% methane, and balance nitrogen/CO₂. This mixture has a calorific value approximately 50% of natural gas per volume.

WWII Precedent

During WWII petroleum shortages, over one million vehicles in Europe ran primarily on wood gas. Sweden alone had 90,000 wood gas vehicles by 1944. The technology was entirely viable for transportation — vehicles adapted gasoline engines to run on wood gas with approximately 30–40% power reduction but continued operation through fuel scarcity.

Modern Gasifier Designs

Modern downdraft gasifiers (Imbert-type) produce cleaner syngas with lower tar content than updraft designs. Small gasifiers suitable for vehicles weigh 150–300 lbs and require processed wood chunks of specific moisture content (<20%) and size. Build plans are available through organizations like FEMA and GEET.

Comparison to HHO

Wood gasification is far more complex than HHO: requires a gasifier unit, cyclone separator, cooling pipes, and filter system. It also requires carrying feedstock. However, syngas can replace a larger fraction of gasoline than HHO — potentially 50–90% on adapted engines. HHO remains simpler; wood gas offers greater fuel displacement for dedicated off-grid applications.