Wood gas generator

wood gas generator is a gasification unit which converts timber or charcoal into a gas , a syngas consisting of atmospheric nitrogen , carbon monoxide , hydrogen , traces of methane , and other gases, which – after cooling and filtering – can then be used to power an internal combustion engine or for other purposes. Historically wood gas generators were often mounted on vehicles , but present studies and developments focused mostly on stationary plants.



Gasification HAD beens year and significant common technology qui Was Widely used to generate coal gas from coal Mainly for lighting Purposes During the 19th and early 20th century. When the first stationary internal combustion engines based on the Otto cycle became available in the 1870s, they began displacing their engines and causing them to lose power. Adoption accelerated after the Otto engine is patent expired in 1886. The potential and practical applicability of gasification to internal combustion engines are well understood from the earliest days of their development.

In 1873, Thaddeus SC Lowe developed and patented the water gas process by which large amounts of hydrogen gas could be generated for residential and commercial use in heating and lighting. Unlike the common coal gas, or coke gas which was used in municipal service, this gas provided a more efficient heating fuel.

During the late 19th century internal combustion engines Were Sometimes fueled by coal gas, and During the early 20th century Many stationary engines switched to using producer gas created from coke qui Was Substantially Cheaper than coal gas qui Was based on the distillation (pyrolysis) of more expensive coal.

In about 1920 French inventor Georges Imbert created the ‘Imbert’ downdraft generator.

During World War II gasoline was rationed and in short supply. In Great Britain, France, the United States and Germany, large numbers of such generators have been constructed or converted into fuel for vehicles. Commercial generators Were in output before and after-the war for use in special Circumstances in gold distressed economies .

Germany produces gasoline units for vehicles, trucks, artillery tractors and even tanks, to preserve the limited supplies of fuel. [1] Even in non-combatant countries, such as Sweden or Brazil, gasogene was popular, as oil became hard to obtain. In Brazil, named Chico Landi won at São Paulo ‘s Interlagos circuit in 1944, driving a wood gas – powered Alfa Romeo. [2]

Post World War II

The US Federal Emergency Management Agency (FEMA) published a book in March 1989 describing how to build a gas generator in an emergency when oil was not available. [3]

The European Union sponsored a wood gas project in Güssing , Austria, starting in 2005. This project was powered by a 2 MW electric power plant and 4.5 MW heat. There was also an experimental device to use the Fischer-Tropsch process to convert diesel fuel to a diesel-like fuel . By October 2005, it was possible to convert 5 kg wood into 1 liter of fuel.


There is a rich literature on gas-works, town-gas, gas-generation, wood-gas, and gas producer, which is now in the public domain due to its age. [4]

Most successful wood gas generators in Europe and the United States are some variation of the earlier Imbert design. Wood gas generators often use wood; however, charcoal can also be used as a fuel. It is denser and produces a cleaner gas with the volatile tarry and excessive water content of wood.

The FEMA unit from 1989 has distinct advantages over the future. to a larger area, causing a drop in temperature; a lower operating temperature leads to tar generation and it lacks a true area reduction further Top Increasing this design’s propensity to Produce tar. Tar in the wood gas stream is considered to be a dirty gas and will be able to speed up, possibly leading to stuck valves, and rings.

A new design known as the Keith gasifier improves on the FEMA unit, incorporating extensive heat recovery and eliminating the tar problem. Testing at Auburn University has proven to be 37% more efficient than running gasoline. [5] This system set the world speed record for biomass powered vehicles [6] and has made several cross country tours. [7] [8]

The United Nations produced the FOA 72 document [9] with details of their wood gas generator design and construction, as well as World Bank technical paper 296. [10]


Wood gas generators have a number of advantages over the use of petroleum fuels:

  • They can be used for internal combustion engines (or gas turbines , for maximum efficiency), using a renewable resource , and in the absence of petroleum or natural gas , for example, during a fuel shortage.
  • They have a closed carbon cycle , contribute to global warming , and are sustainable in nature.
  • They can be made easily in a crisis using materials on hand.
  • They are far cleaner than burning a wood fire or a gasoline-powered engine (without emission controls ) Producing little, if any soot.
  • When used in a stationary design, they reach their true potential, they are possible to use in their combined heat and power scenarios (with heat recovery from the wood gas producer, and possibly the engine / generator, for example, to heat water for hydronic heating ), even in good economic times, provided a sufficient supply of wood is possible. Larger-scale facilities can reap even better efficiencies, and are Useful for heating district as well.


The disadvantages of wood gas generators are:

  • the large specific size
  • the relatively slow starting speed; the time to heat up the temperature and the temperature of the room.
  • a batch burning operation, which some designs feature, and that which occurs regularly in the production process.
  • the stop-and-go operation of a gas-fired machine: the residual heat still produces gas, which for a certain time leaves the gasifier burner
  • the primary fuel fuel-gas produced during gasification is carbon monoxide : it is an intentional fuel-product, and is subsequently burned to safe carbon dioxide in the engine (or other application) along with the other fuel-gases; However, continuous exposure to carbon monoxide can be fatal to humans in small to moderate concentrations.
  • the humidity of the wood (usually 15 to 20%) and the water vapor created by the O- and H-atoms of the dry wood (condiments during the gas) liquid and filtering procedure and yields a liquid (see also wood tar ), which needs specific water treatment. This treatment requires about 25 to 35% of the original wood gas energy.

Safety consideration

When using a large percentage of poisonous carbon monoxide (CO) gas , there is considerable potential for injury or death . Wood gasifiers of proven and thoroughly tested construction are considered to be safe for use, or in a separate environment, for example, under a shelter open to the air on two sides; they may also be considered to be extremely safe (eg, negative pressure ), fully independent, battery-powered, regularly tested carbon -monoxide gas detectors. However, caution must be kept in mind that the design of the building is thoroughly tested, and only with a “buddy” at all times, and with constant vigilance for any sign of headache, drowsiness, or nausea, as These are the first symptoms of carbon monoxide poisoning.

In addition, mixtures of excessive quantities of air and gas should be avoided if combustion is present. Long-term storage of wood-gas, except through the use of a gasholder -type water-displacement apparatus, which should not be attempted, to the volatile elements present in the gas, which, if allowed to excessively precipitate, will condense in the storage vessel. Under no circumstances should be more expensive than 1 bar (15 psi) above ambient, as this may be induce condensation of volatiles, as well as lead to the likelihood of severe injury or carbon monoxide or deflagration if the vessel leaks or fails. quote needed ]

Media coverage

In 2008, an example of designing and constructing a portable fuel generator is shown on the National Geographic Channel’s Planet Mechanics in the eighth episode, “Tree Powered Car”. [11]

In 2009, another example of designing and constructing a working gas powered generator engine was in the TV series The Colony in the second episode of the first season “Power Struggle”. Also used in the tenth episode “Exodus” to power an escape vehicle.

This truck set the land speed recordfor biomass powered vehicles in September 2011

A 2010 Mother Earth News article discussed and shown pictures of a wood gas powered engine installed in a truck pickup. [12] As part of the BBC science series “Bang Goes The Theory”, a Volkswagen Scirocco was converted to a design by Martin Bacon to run on coffee grounds , and after its construction in London to Manchester successfully. Part of the team are working on a more advanced design.

On September 14, 2011, at the Bonneville Salt Flats has a new world speed record for vehicles powered by a speed of 73 mph. [13]

On the popular US radio program Car Talk , a caller in episode 1201 (qui aired on January 7, 2012 and Was subsequently named “20 Miles Per Woodchip”) Described a wood gas Generating vehicle he rode in as a boy During World War II in Germany. The hosts were not familiar with the technology, because it was never adopted in the US.

On March 12, 2012, a season 2 Episode of Doomsday Preppers, a wood gas generator is shown on Ford truck and a house by Scott Hunt on his multi-acre woodland property in South Carolina.

Serbian TV sitcom “Truckdrivers 2” (= “Kamiondzije II”) from 1983. talks, as a part of plot, about a gas generator affixed to a chassis of a lorry.

An article appeared in Mother Earth News in April 2012 featuring the Keith gasifier, showing pictures and talking with inventor Wayne Keith. [14]

In the BBC Documentary Wartime Farm , Episode 5 (aired October 2012) they built a gas powered gas powered vehicle. [15]

In Season 3 Of Mountain Men On The History Channel, Eustice Conway is shown operating a wood gasified Toyota pickup for hauling goods

The Finnish prime minister Juha Sipilä has received some media attention for the fuel market as a result of his political career. [16]

List of commercially available systems

There are only a few companies that produce wood gasifier systems commercially. A list can be found here below. Since wood gas systems have the tendency of being rather broad, most focus on stationary applications (electricity production). Some may be suitable for building into vehicles though. [17] [18]

  • Holzenergie Wegscheid GmbH
  • Entrade Energiesysteme AG
  • Vulcan Gasifier LLC
  • Victory Gasworks
  • Garringer Gasifier
  • ALL Power Labs
  • Husk Power Systems
  • STAK Properties LLC
  • Foutch Manufacturing
  • Community Power Corporation
  • Gasógenos GADA
  • REP Renewable Energy Products GmbH
  • Gasification Australia Pty Ltd
  • International Supply Biz
  • Borealis Wood Power Corp
  • Zhengzhou Shuliy Machinery Co., Ltd
  • Volter
  • Spanner Re² GmbH
  • MRC Green
  • Associated Engineering Works
  • National Innovation Foundation – India,
  • Trillion Gasifiers
  • Northern Self Reliance
  • Superior Gasification
  • Tactical Wood Gas Inc [19]

See also

  • Gas engine
  • Engine-generator ; can be connected to the gasifier via a wood gas hose, hereby also being able to produce power when the vehicle is not running, in effect forming a vehicle-to-grid system
  • Exhaust heat exchanger : can be used to help heat the gasifier, increasing gas output of the wood gasifier
  • Stirling engine : Another engine that uses heat from wood, rather than needing to convert it to wood gas [20]
  • Hot air engine : similarly to the stirling engine, can use heat directly and can run on wood [21]


  1. Jump up^ “The Eastern Front Forum” . East Front.
  2. Jump up^ Wolfe, Joel (2010), Autos and Progress: The Brazilian search for Modernity , New York City: Oxford UP, p. 108, ISBN  978-0-19-517456-4
  3. Jump up^ H. LaFontaine, FP Zimmerman (1989) Construction of a Simplified Wood Gas Generator for Fueling Internal Combustion Engines in a Petroleum Emergency , FEMA Publication
  4. Jump up^ Literature about the history and manufacture of wood and coal gas generators can be found using online book digitization projects, Such As Google Books, and thesis Often-have Such materials downloadable in full, as They Have Passed into thepublic domaindue to Their age. For example, searching for “Producer Gas”, “Gas manufacture and works”, or “Gas Generators” onGoogle Bookswill yield Many full books on the subject That can sate the appetite of one interested in thehistory of technologyor serve the amateur experience well, even dated as they are.
  5. Jump up^ Dr. David Bransby (July 10, 2010). “Auburn University Test Results” . Drive On Wood . Retrieved 2012-04-12 .
  6. Jump up^ Dr. David Bransby (December 28, 2011). “Wayne Keith sets a new world wood gas speed record” . Biofuels Digest . Retrieved 2012-04-12 .
  7. Jump up^ Dr. David Bransby (September 2008). “Bio-truck: Coast to Coast and Back” . Auburn University . Retrieved 2012-04-12 .
  8. Jump up^ Michael C. Bolton (September 15, 2011). “Springville AL inventor breaks records in his wood burning pickup” . Birmingham News . Retrieved 2012-04-12 .
  9. Jump up^ United Nations FOA 72
  10. Jump up^ World Bank 296
  11. Jump up^ [1]Google search
  12. Jump up^ Rick Bates (February-March 2010). “Use a Wood-gas Generator to Power Your Truck” . Mother Earth News . Retrieved 2010-05-11 .
  13. Jump up^ John Rockhold. “73MPH On Wood Gas New Record Sets” . Mother Earth News . Retrieved 10-9-2011 . Check date values ​​in:( help ) |access-date=
  14. Jump up^ Richard Freudenberger (April-May 2012). “Wood Gas Wizard” . Mother Earth News . Retrieved 2012-04-12 .
  15. Jump up^ “BBC Wartime Farm Website” . BBC . Retrieved 2012-10-06 .
  16. Jump up^ Camino-Driving, Jalopnik-Endorsed Badass Elected Leader Of Finland. Jalopnik 2015-04-20. Retrieved 2015-07-07
  17. Jump up^ GEK build into car
  18. Jump up^ Foutch Manufacturing building LEAF into school bus
  19. Jump up^ List of additional wood gas generator suppliers
  20. Jump up^ Stirling engine animation
  21. Jump up^ Hot air Stirling engine example