Wood gas is also known as Syngas or Producer Gas. This technology is as old as the hills; the actual process is almost forgotten. Those of us fortunate enough to have had a parent who built one of these in the Second World War, and taught this technique to their offspring, can, fortunately, continue and revive and refine this amazing plant.
Wood gas uses intense heat from burning off cuts of wood, pelletized grains and stalks etcetera in order to break down the cellulose to release hydrogen and other combustible gases.
Woodgas reactors are commonly known as Wood Gasifiers. They have a way back history dating to the Second World War when fuel was in short supply worldwide. Some of us today (ourselves included) are fortunate enough to have some hands-on experience at making one of these and seeing how very efficient they actually are at producing gas. These gasifiers were mounted to cars trucks and buses and also motorcycles!
Woodgas reactors also come in the form of stoves. The most basic of these is known commonly as a Rocket Stove intense heat and uses less wood than a fire but soils the cooking pot as a fire would do. The more advanced unit is called a Gasifier Stove. Burning a very improved flame, it will not soil pots as badly as a fire or rocket stove would. It is also more efficient on wood fuel than a rocket stove.
Wood Gas Reactors available worldwide today Consist primarily of 3 types:
Updraught, where the produced gas is flowing from the bottom of the reactor to the top, where it is also loaded, and out to the cleaning and scrubbing sections. Suitable for insensitive uses such as heating flame as it is high in un-cracked tars.
Fluidised bed, where there is air or gas agitation of the feed (usually fines) wood or other fuel. The flow is upwards. Efficient energy for flames, but the gas is dirty, loaded with tars and other impurities. Needs much filtration.
Downdraught, where the gas flow is downwards. This to date has been the most popular choice for research. This gas in its untreated state does have tars, but not nearly as much as the above two types. There are many variations of down draught reactors, each inventor claiming success (in varying degrees of) tar cracking. Truth be told, if the wood is burned above 1000 degrees Celsius, most of the tars can be cracked. This is proven in laboratory studies. Our design can elevate the temperature of flame to 1250 degrees centigrade. Our wood chip tar filters recycle the chips and trapped tar back to the fire box and thus we crack ALL the tars to gas.
Wood Gas is a rapid burn fuel, burning very fast at the point of ignition to the extent that the engine needs to have its timing altered to maximise the energy of this fast burn. It does not have the higher energy values of fossil type fuels, but it does have about 70 to 80% efficiency upon ignition in an internal combustion engine. This gas can be used for boilers and other heating sources, but the reactor plant itself is not recommended for closed spaces due to possible carbon monoxide exposure (The same applies to generators and engines using petrol or diesel and even lp gas).
Wood Gas Reactors can be used to produce power (in places that produce large amounts of waste wood offcuts like saw mills, timber working enterprises and suchlike) by supplying fuel either as fossil fuel replacement, or it can be utilised as a primary fuel supply.
An excellent source of energy in emergencies.
Burns almost any pelletized dry vegetative matter.
Burns best with wood chunks but chips can also be burnt.
Solves sawmill headaches of waste wood disposal in producing engine gas for a generator- A sawmill can thus be self-sustaining and off-grid.
Excellent energy/mass conversion compared to fossil fuel (See CON section).
Although they have excellent energy/mass conversion figures for the power delivered, it needs to be borne in mind that the power peak Kw delivered is about 70% of the power peak kW delivered of petrol/diesel fuel.
Needs a good supply of dry wood or pelletized sawdust/vegetative matter.
Need 10 minutes to get gas volume built up.
Cheric Energy can custom-build your wood gas reactor to suit your requirements. Our wood gas generator design uses stainless steel and high-temperature ceramic components, and we truly believe it is far more efficient than fossil fuel despite the 70% power reduction, in that it can produce hot air as well as very hot water in a single unit. This makes the gasifier much more than 100% efficient.
Cheric Energy can make a unit for a small 7.5 kW engine right up to a great big 5 litre V8 petrol engine. Diesel engines can be modified to run on gas alone or gas-assisted operation. Both diesel options require fairly extensive engineering, and this can be more expensive possibly than replacing the compression engine with a spark firing engine.