Wood gasifier on a Ford truck converted to a tractor (an EPA tractor).

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Wood gas, also known as holzgas, air gas or blue gas, is the product of thermal gasification of biomass or other carbon containing materials such as coal in a gasifier or wood gas generator. It is the result of a high temperature reaction (>700 °C), where carbon reacts with steam or a limited amount of air or oxygen producing carbon monoxide (CO), molecular hydrogen (H₂), and carbon dioxide (CO₂). Image File history File linksMetadata Wood_gasifier_on_epa_tractor. ... Image File history File linksMetadata Wood_gasifier_on_epa_tractor. ... This article or section does not cite its references or sources. ... Image File history File links Portal. ... For the water carbonator, see Gasogene. ... Switchgrass, a hardy plant used in the biofuel industry in the United States Rice chaff. ... Coal Coal (IPA: ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... This article or section does not cite its references or sources. ... Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ...

In several gasifiers the actual gasification process is preceded by pyrolysis, where the biomass or coal turns into char releasing polycyclic aromatic hydrocarbon (PAH) rich tar and methane (CH₄). Other gasifiers are fed with previously pyrolysed char. Wood gas is flammable because of the carbon monoxide, hydrogen and methane content. Simple sketch of pyrolysis chemistry Pyrolysis usually means the chemical decomposition of organic materials by heating in the absence of oxygen or any other reagents, except possibly steam. ... An illustration of typical polycyclic aromatic hydrocarbons - NASA Crystal structure of a hexa-peri-hexabenzocoronene reported by Müllen and cooworkers in Chem. ... Tar is a viscous black liquid derived from the destructive distillation of organic matter. ... Methane is a chemical compound with the molecular formula CH4. ...

Usage

Wood gas can be used to power cars with ordinary internal combustion engines if a wood gasifier is attached. This was quite popular during World War II in several European countries because the armies active in the war did not always have access to oil. In more recent times, wood gas has been suggested as a clean and efficient method to heat and cook in developing countries, or even to produce electricity when combined with a gas turbine or internal combustion engine. Compared to the WWII technology, gasifiers have become less dependent on constant attention due to the use of sophisticated electronic control systems, but it remains difficult to get clean gas from them. Purification of the gas and feeding it into the natural gas pipelines is one variant to link it to existing refuelling infrastructure, liquification by the Fischer-Tropsch process is the other possibility. This article or section does not cite any references or sources. ... This article or section does not cite its references or sources. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... // The Fischer-Tropsch process is a catalyzed chemical reaction in which carbon monoxide and hydrogen are converted into liquid hydrocarbons of various forms. ...

Production

Fluidized Bed Gasifier in Güssing Burgenland Austria operated on wood chips

A wood gasifier takes wood chips, sawdust, charcoal, coal, rubber or similar materials as fuel and burns these incompletely in a fire box, producing solid ashes and soot (which have to be removed periodically from the gasifier and constantly from the gas) and wood gas. The wood gas can then be filtered for tars and soot/ash particles, cooled and directed to e.g. an internal combustion engine, gas turbine, Stirling engine or fuel cell to produce electricity. Most of these devices have severe requirements to the purity of the wood gas, so the gas often has to pass through extensive gas cleaning in order to remove or convert (i.e. to "crack") tars and particles. If you plan to run wood gas in an internal combustion engine, get to know your local cylinder head repair shops. Image File history File links Download high-resolution version (800x761, 106 KB) Holzvergaser Güssung 2006 eigene Aufnahme File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Wood gas Güssing Fischer-Tropsch process Cellulosic ethanol ... Image File history File links Download high-resolution version (800x761, 106 KB) Holzvergaser Güssung 2006 eigene Aufnahme File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Wood gas Güssing Fischer-Tropsch process Cellulosic ethanol ... Güssing ( in Hungarian Németújvár ) is a town in Burgenland, Austria The lords of Güssing (in Hungarian: Köszeg, in Slovak: Kysak) were a noble family in the frontier region of Austria and the Kingdom of Hungary. ... Burgenland (Hungarian Várvidék, Őrvidék or Felsőőrvidék, Croatian Gradišće, Slovenian Gradiščansko) is the easternmost state or Land of Austria. ... This article or section does not cite any references or sources. ... This machine has a single-stage centrifugal compressor and turbine, a recuperator, and foil bearings. ... Cut away diagram of a Rhombic Drive Beta Stirling Engine Design Pink - Hot cylinder wall, Dark grey - Cold cylinder wall (with coolant inlet and outlet pipes in Yellow), Dark Green - Thermal insulation separating the two cylinder ends, Light Green - Displacer piston, Dark Blue - Power piston, Light Blue - Flywheels, Not Shown... A fuel cell is an electrochemical device similar to a battery, but differing from the latter in that it is designed for continuous replenishment of the reactants consumed; i. ...

The heat of combustion of producer gas is rather low compared to other fuels. Taylor ^[1] reports that “producer gas” has a lower heating value of 5.7 MJ/kg versus 55.9 MJ/kg for natural gas and 44.1 MJ/kg for gasoline. Presumably, these values can vary somewhat from sample to sample. The same source reports the following chemical composition by volume which most likely is also variable: Heating value (or calorific value) is used to define the amount of heat released during the combustion of a fuel or food. ...

A Charcoal Gas Producer at an alternative festival Nambassa 1981.

• Nitrogen N₂ 50.9%,
• Carbon monoxide CO 27.0%,
• Hydrogen H₂ 14.0%,
• Carbon dioxide CO₂ 4.5%,
• Methane CH₄ 3.0%,
• Oxygen O₂ 0.6%.

The quality of the gas from different gasifier varies a great deal. Staged gasifiers, where pyrolysis and gasification occur separately (instead of in the same reaction zone as was the case in e.g. the WWII gasifiers) can be engineered to produce essentially tar-free gas (<1 mg/m³), while single reactor fluid-bed gasifiers may exceed 50,000 mg/m³ tar. The fluid bed reactors have the advantage of being much more compact (more capacity per volume and price). Depending on your intended use of the gas, tar can be beneficial as well; increasing the higher heating value of the gas. Image File history File linksMetadata Nambassa_1981_Alt. ... Image File history File linksMetadata Nambassa_1981_Alt. ... Nambassa was a series of hippie-conceived festivals held between 1976 and 1981 on large farms around Waihi and Waikino in New Zealand. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Methane is a chemical compound with the molecular formula CH4. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ...

History

The first wood gasifier was apparently built by Bischof in 1839. The first vehicle powered by wood gas was built by Parker in 1901. Blue gas was used as a secondary fuel source for some zeppelin designs of the early 20th century, stored in gas cells within the envelope, just below the hydrogen gas cells. The engines could use either the blue gas or liquid petroleum-based fuel for power. Around 1900, many cities delivered wood gas (centrally produced typically from coal) to residences. At this time also, Rudolf Diesel and Georges Imbert were also developing their various engines. It has been theorized that all of these internal combustion engines had been inspired by observing the operation of the fire piston fire making device which had been discovered in New Guinea and Sumatra early in the 1800s. Natural gas began to be used only in 1930. Wood gasifiers are still manufactured in Singapore, China and Russia for automobiles and as power generators for industrial applications. 1839 (MDCCCXXXIX) was a common year starting on Tuesday (see link for calendar). ... 1901 (MCMI) was a common year starting on Tuesday (link will display calendar) of the Gregorian calendar (or a common year starting on Wednesday of the 13-day-slower Julian calendar). ... This article is about Rudolf Diesel, the German inventor. ... A fire piston is an ancient device which is used to start fires. ... Sumatra (also spelled Sumatera) is the sixth largest island in the world (approximately 470,000 km²) and is the largest island entirely in Indonesia (two larger islands, Borneo and New Guinea, are partially in Indonesia). ... Natural gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide. ...

See also

• Manufactured Gas Plants

External links

• Biomass Energy Foundation (American) extensive site on wood gas and gasifiers, http://www.woodgas.com/ .
• Food and Agriculture Organization of the United Nations: Wood Gas as Engine Fuel, 1986, http://www.fao.org/DOCREP/T0512E/T0512e00.htm. Detailed explanation of the theory and praxis of wood gasifiers, including dangers and downsides.
• Hans Hochwald: Wood gas producers, http://highforest.tripod.com/woodgas/woodgas.html. A schematic of a wood gasifier, and links.
• Report about an '85 Yugo car converted to wood gas by Igor and Anton Peterka: http://freeweb.deltha.hu/zastava.in.hu/wood-gas.htm
• Description of several wood gas stoves: http://journeytoforever.org/at_woodfire.html
• GasNet, European Union biomass gasification research coordination, http://www.gasnet.uk.net/
• Tar measurements on gasifiers, European standardisation effort, http://www.tarweb.net/
• Description of Fire Piston,

http://www.geocities.com/firepiston/ link broken try http://web.archive.org/web/20050206184859/http://www.geocities.com/firepiston/

• Information to build/use your own wood gasifier for the auto,

http://www.gengas.nu/byggbes/index.shtml

• Economic evaluation of operation of vehicles on wood gas
• Info about wood gas as vehicle fuel
• Woodgas-International.com International discussion group covering wood gasification techniques, with sections devoted to automobile-based gasification and cooking/heating applications. Based in Germany, with both English and German language sections.
• Finnish "eco"-car association (wood fueled car association) (in Finnish)
• Experimental single chamber gassifying high moisture wood chip furnace (For home heating - outside hot water type)

References

1. ^ Taylor, Charles Fayette (1985). Internal-Combustion Engine in Theory and Practice - Vol.1. Cambridge: The MIT Press, pp. 46-47. ISBN 0-262-70027-1.