17 Mar. 1979|
Wood gas vehicle plans,green woodworking tools for sale,diy wine storage cabinets,wood plank flooring lowes - For Begninners
Our wood gas truck has racked up 1,500 miles running on wood chips and wood scrap, and is still going strong. Wood gasification is a thermo-chemic way to extract flammable gases from wood, leaving nothing but a few small char particles -known as bio-char- and some condensate.
Unfortunately, the ready wood gas is substantially diluted with useless nitrogen (N2) which came in with the incoming air. Soft woods, like coppice willow, are fast and easy to grow and will gasify excellently in a well-dimensioned gasifier. After the generator comes an extensive cleaning train, since the gas is dusty with carbon particles and is water-saturated.
Wood is virtually free, because trees can thrive on land that is not suitable to grow crops.
If the car wood is made and transported by petroleum-fueled machines, the fossil CO2 output is only about 10 grams per driven kilometer.
One can harvest 1,000 km worth of car wood –that is about 1 m3 of loosely filled wood blocks - in 8 hours. A woodgas-powered car will not allow you to get somewhere fast, but it will allow you to get there. Since a few years back, commercial manufacturers of small gasification systems has become active in many countries, including the US. I knew they did this back during WWII, but did not know of actual practioners of the black art of wood-gassified cars.
I also wonder about the competitiveness of burning wood for a steam engine instead - or additionally using waste heat from a wood-gassified car to cogenerate steam for additional power.
In the Scandinavian countries, woodgasification always got more interest, just because the availability of so much wood.
If I could use these wood chips in a co-gen set-up like you described, not only could I make electricity, but the bio-char "waste" is an awesome soil amendment if used properly. A community of gasification enthusiasts hosted by Wayne Keith, resident expert & woodgas pioneer.
The gasifier and engine are connected, so the draw of the engine determines how much gas is being produced. Although oil has potential to bring more energy, it adds to the tars that distillate out of the wood.
But the most pleasant advantage of wood as an engine fuel is the fact that it is accessible to almost everyone. Bulky gasifier systems feed an electric power generator while most of the heat is recaptured and used to dry the wood and heat buildings. If you make the wood fuel all by hand and don’t eat much meat, the fossil CO2 output is minus 10 grams per kilometer. While the basic wood block fuel can produce excellent numbers, we still have to take the refinery into account.
The gasifier, wood and operator all have to work in a successful trinity, otherwise it will not work. When you want to build a wood gasification system yourself, a couple of hundred hours studying cannot be avoided.
I am always looking for ways to exploit my local waste streams, and one of the "wastes" readily available to me is wood chips from the local tree-service companies. Since wood is the most accessible, free and ever-regenerating storage medium of solar energy, it would be a shame not to use it. These make the gas low from a calorific standpoint and reduce engine power to about 60 % of the original power vs petrol. As I mentioned earlier, these tars have to be cracked into smaller hydrocarbons in the hot part of the gasifier. Meanwhile the temperature of the gas is lowered towards the dew point, so after the cyclone comes a cooler to remove the condensed water. It is possible to refine wood gas to a liquid using the so-called Fischer-Tropsch process, but not on a small personal scale.
A well-designed gasifier in combination with an experienced operator will minimize this danger. Gasification (as well as simply building a gasifier) is a combination of thermodynamics, math, material knowledge and manual crafts.
They are an excellent choice if you want a gasifier and have more money than manual skills.
This article will not deal with the direct burning of wood, nor with gasifiers meant for heating purposes. This is done by burning about 15% of the wood by means of injecting a restricted flow of air, but at high velocity.
It’s a tricky process, taking place in a very short time, and is therefore sometimes not completely done.
Stationary systems are often much bigger compared to vehicle gasifiers, less compromised and therefore more reliable, easier-to-control, and produce cleaner gas. We cannot make cars from wood; they still need inputs of fossil energy and other commodities. Wood gas cannot be stored by compressing it, since carbon monoxide is an unstable gas and will fall apart under pressure. They have designed the Power Pallet which produces 10kWe, sort of the wood powered off-gridder.
Instead, we’ll talk about wood gas generators connected to internal combustion engines and vehicle engines in particular.
Of course, first the gasifier has to be fired up with the help of a fan, creating and artificial draw.
Between the restriction plate (fat black drawn) and the grate, the actual reduction to carbon monoxide and hydrogen takes place.
On the scale of personal transportation, a wood-powered car is somewhere in the middle if the scale has a petroleum fueled car on one end and a horse on the other. Besides that, it cannot be scaled up to present mileages, simply because there is not enough wood. A sharp brain, patience and perseverance are needed regardless Buying a gasifier and immediately storing it for crisis times is not the way to go. I have been following them for quite sometime and even visited for a bit (search "monk welds gasifier"). Tarry gas is the worst enemy of a woodgasser (guys who drive on wood) and the most difficult one to fight. A wood-powered car is slightly more sustainable than a biodiesel-fueled car, because preparing the basic fuel (wood blocks versus vegetable oil) asks for less - or even no - fossil input. Once ready, the black art starts… Yet, a very simple gasifier can be made in only one day. During this oxidizing stage, the remaining wood becomes char and the escaping tars are cracked by the heat into much smaller hydrocarbons. After all, wood is bundled solar energy, allowing for a continuous power supply (which cannot be said of PV panels or wind turbines). It is exciting and stimulating to obtain a perfect purple flame from a black box filled with chopped wood. However, the tar and ash must be removed from the gas or they may produce deposits, possibly resulting in engine damage. Should the wood only be used for electric power generation and the heat being wasted, then I consider it again as a crisis fuel.
So, to clean the fuel, the "smoke" is first routed through a liquid-cooled "densifier" (a multitubed heat exchanger surrounded by a water jacket and plumbed into a junk automobile air conditioning condenser that's mounted in front of the existing radiator), which precipitates moisture and residue from the gas. By referring to the accompanying color photograph, you can see that the extreme left (silver) clevis controls the forward (wood gas) throttle plate, the central (red) fastener governs the movement of the rear (fresh air) valve, and the far right (black) U-clasp puts the gasoline carburetor's accelerator rod in motion.The broad blue arm in the middle of the assembly functions as a master control, and is connected to the truck's "gas" pedal. As it moves laterally, this simple arrangement regulates the operation of either the gasoline or the wood gas (or both) throttle. Instead of allowing the sliding control pin to move both "smoke fuel" clevises at the same time, they drilled an access hole in only the right shoulder of the air mix (red) arm and fastened a short spring between the lever's slotted bracket and that of its silver-colored (wood gas) neighbor. When the handle is pulled to its midway position, both the wood gas and petrol throttles function, allowing the motorist to pull away while rapidly bringing the gasification unit up to a good fuel-producing temperature.
Since, in this configuration, there's not sufficient draw to influence the carburetor, very little if any gasoline enters the manifold through that atomizer's idle circuit.