Direct solid wood to gas conversion creates a large percentage of hydrogen as a flammable gas. Hydrogen is a boon for clean combustion. Hydrogen energy is kind of a holy grail in energy circles.
1966 Hydrogen Vehicle Prototype
But when hydrogen is mentioned, it brings up an often asked question - Is this safe?
Any gas with enough power to pop in a combustion chamber, drive a piston, and power a vehicle at highway speeds is obviously explosive. Gasoline and diesel do their job well because they explode well. Folks are good with the inherent dangers of this robust explosive power stored in tanks onboard the vehicle.
A wood powered engine operates on "producer gas". That is gas that is produced just moments before it is consumed. The suction of the engine powers the process, so if the engine dies, the process stops. A 120 pound hopper of wood contains about a million potential btu. Wood requires continuous processing, the engine running, to make useful gas. A 20 gallon tank of gasoline contains over 2 million potential btu ready to blow up with the right mixture of heat and oxygen.
Relatively speaking, producer gas is far safer than fossil fuels onboard a vehicle in terms of immediate explosive capability.
Safe for Eons vs?
In eons of biomass energy use, there were never any huge scale problems. Current energy paradigms are potentially unsafe at massive scale.
BP Horizon Blowout Covers the Gulf of Mexico in Oil
Fukushima Nuclear Energy Disaster - Still in Process
Kuwait Oil Field Fire as Nations Fight to control "Cheap" Oil
Wildfires - vast potential energy wasted
Fracking is basically the art of pumping clean water from above ground mixed with proprietary chemical concoctions into the earth to create fissures and pressure to drive out "natural" gas. Fresh water is removed from the above ground cycle, contaminated, then circulates everywhere below ground that water flows. Next problem, clean water.
So overall big picture, biomass energy is the safest known energy resource. It operates completely within the existing carbon cycle, powered by the daily passage of the sun overhead. Done wisely, saving the biochar for use in the soil, biomass reverses the recent global environment change wrought by pump and dump fossil fuel technologies. Biochar also improves soils, creating more biomass growth, and purifies water.
"If our recently devised economic system puts at risk the air, water, land and biodiversity that we rely on for our health and very survival, we must come up with something better." - David Suzuki