Can vehicles really run on gas produced from wood?
Wayne Keith is not concerned about the gas price hikes caused by the war in Iraq, increased demand from China and India, or hurricane Katrina. Neither is he concerned about the 1968 huge (390 cubic inch) gas-guzzling engine in his farm pickup. In fact, as far as Keith is concerned, the bigger the engine, the better, and he feels that the performance of his truck would be improved if he had an even larger engine. This is because he has retrofitted this vehicle to run on gas produced by partially burning wood.
The Keith family is remarkably self sufficient in many ways. They are not worried about power outages, because electricity for their home is generated by a self made windmill. Wayne and his wife, Lisa, also built their attractive log home with no help, and with lumber they harvested from their farm and processed through their home made sawmill. Their main activities on their farm near Springville in St. Clair County are beef cattle and hay production, for which they need a pickup and gooseneck trailer for hauling.
Keith indicates that a cord of logs brings no more than $27 in most local markets these days, but he claims that if wood is used to fuel his pickup, a cord could be worth as much as $900 with gas prices around $3.00/gal. But since the wood he uses for fuel is residue from his sawmill, as far as he is concerned, it’s free. And while most of us are concerned about the current cost of gasoline every time we get into our cars to go somewhere, Keith doesn’t think twice about going for a leisure drive every Sunday afternoon, in addition to putting his pickup to work during the week.
The technology is not new: it was used in Germany in response to gasoline shortages during World War II. It involves gasification of wood in a small gasifier, and using the resultant wood gas or synthesis gas (commonly referred to as syngas) instead of gasoline to fuel the engine in the truck. More specifically, Keith has built a 6 ft. reactor or gasifier in the bed of his pickup. He places relatively large pieces of wood into this apparatus, and ignites it. The lid of the gasifier is then closed to limit the amount of air (and therefore oxygen) that enters.
Under normal combustion conditions, such as with an open fire or many conventional furnaces where air and oxygen are not limited, the products of combustion are mainly carbon dioxide, water and ash. However, when oxygen is limited, combustion is incomplete, and a mixture of gases (mainly carbon monoxide, hydrogen and a small amount of methane) is produced, along with some ash. This syngas is highly flammable, and can be used to replace gasoline.
At the point of production in the gasifier, the syngas is extremely hot (over 2000º F) and needs to be cooled down. Keith achieved this by building a gas radiator that is mounted behind the cab of the pickup. The gas is then cleaned up by running it through a filter, which is simply a small barrel containing hay and mounted in front of the hood. Finally, this remarkably clean gas is directed to the carburetor to replace gasoline.
The system is designed to start on gasoline, but within a minute or two it is switched to wood gas. Controls for the wood gas include a separate
accelerator peddle, to the left of the brake peddle, and operated with the left foot, and a lever on the steering column to control the amount of oxygen to the gasifier, and therefore, the composition of the gas.
Keith emphasizes that the wood must be dry when placed in the gasifier. So before using it as a fuel for his truck, he dries the wood by heating it with fire in barrels. He also points out that his 6 ft. gasifier was designed to take him about 100 miles without having to refill it, and that it is necessary to remove about 2 gal. of ash every 1,000 miles. The pickup travels at 60 miles per hour comfortably, and can reach 80 miles per hour in the winter when the humidity is low.
Wayne is quick to point out that his wood fired pickup is not polluting, if compared to vehicles that run on gasoline or diesel. And of course, this is perfectly true, especially with regard to green house gases. When we burn gasoline or diesel which are derived from oil, it amounts to removing carbon from below the ground (in oil wells) and releasing it into the atmosphere, thus adding to the atmospheric pool of greenhouse gases, and the risk of global warming.
Because trees extract carbon from the air as they grow, burning wood just recycles it back into the atmosphere. Keith’s pickup is therefore carbon neutral. In addition, there is no visible sign of emissions from the engine when he is traveling, as is the case with so many diesel vehicles, and Keith is proud to show how clean the spark plugs are, compared to those in vehicles that run on gasoline.
In summary, Wayne Keith and his family are to be admired and congratulated for a remarkable example of rural ingenuity and self-sufficiency, and their obvious commitment to environmental responsibility.