Producer gas is
fuel gas
Fuel gas is any one of a number of fuels that under ordinary conditions are gaseous. Most fuel gases are composed of hydrocarbons (such as methane or propane), hydrogen, carbon monoxide, or mixtures thereof. Such gases are sources energy t ...
that is manufactured by blowing a
coke or
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when dea ...
with air and steam simultaneously.
It mainly consists of
carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
(CO),
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
(H
2), as well as substantial amounts of
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
(N
2). The caloric value of the producer gas is low (mainly because of its high nitrogen content), and the technology is obsolete. Improvements over producer gas, also obsolete, include
water gas
Water gas is a kind of fuel gas, a mixture of carbon monoxide and hydrogen. It is produced by "alternately hot blowing a fuel layer okewith air and gasifying it with steam". The caloric yield of this is about 10% of a modern syngas plant. F ...
where the solid fuel is treated intermittently with air and steam and, far more efficiently
synthesis gas
Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide, in various ratios. The gas often contains some carbon dioxide and methane. It is principly used for producing ammonia or methanol. Syngas is combustible and can be used ...
where the solid fuel is replaced with methane.
In the USA, producer gas may also be referred to by other names based on the fuel used for production such as
wood gas
Wood gas is a fuel gas that can be used for furnaces, stoves, and vehicles. During the production process, biomass or related carbon-containing materials are gasified within the oxygen-limited environment of a wood gas generator to produce a c ...
. Producer gas may also be referred to as suction gas. The term suction refers to the way the air was drawn into the gas generator by an internal combustion engine.
Wood gas
Wood gas is a fuel gas that can be used for furnaces, stoves, and vehicles. During the production process, biomass or related carbon-containing materials are gasified within the oxygen-limited environment of a wood gas generator to produce a c ...
is produced in a
gasifier
Gasification is a process that converts biomass- or fossil fuel-based carbonaceous materials into gases, including as the largest fractions: nitrogen (N2), carbon monoxide (CO), hydrogen (H2), and carbon dioxide (). This is achieved by reactin ...
Production
Producer gas is generally made from
coke, or other
carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...
aceous material such as
anthracite
Anthracite, also known as hard coal, and black coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the hig ...
. Air is passed over the red-hot carbonaceous fuel and
carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
is produced. The reaction is
exothermic and proceeds as follows:
Formation of producer gas from air and carbon:
:C + O → CO, +97,600 calories/mol
:CO + C → 2CO, –38,800 calories/mol (mol of the reaction formula)
:2C + O → 2CO, +58,800 calories/mol (per mol of O i.e. per mol of the reaction formula)
Reactions between steam and carbon:
:HO + C → H + CO, –28,800 calories/mol (presumably mol of the reaction formula)
:2HO + C → 2H + CO, –18,800 calories/mol (presumably mol of the reaction formula)
Reaction between steam and carbon monoxide:
:HO + CO → CO + H, +10,000 calories/mol (presumably mol of the reaction formula)
:CO + H → CO + HO, –10,000 calories/mol (presumably mol of the reaction formula)
The average composition of ordinary producer gas according to Latta was: CO: 5.8%; O: 1.3%; CO: 19.8%; H: 15.1%; CH: 1.3%; N: 56.7%; B.T.U. gross per cu.ft 136 The concentration of carbon monoxide in the "ideal" producer gas was considered to be 34.7% carbon monoxide (carbonic oxide) and 65.3% nitrogen. After "scrubbing", to remove
tar
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bit ...
, the gas may be used to power
gas turbine
A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...
s (which are well-suited to fuels of low calorific value), spark ignited engines (where 100% petrol fuel replacement is possible) or diesel internal combustion engines (where 15% to 40% of the original diesel fuel requirement is still used to ignite the gas ). During
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
in Britain, plants were built in the form of trailers for towing behind commercial vehicles, especially buses, to supply gas as a replacement for petrol (gasoline) fuel. A range of about 80 miles for every charge of anthracite was achieved.
In old movies and stories, when describing suicide by "turning on the gas" and leaving an oven door open without lighting the flame, the reference was to coal gas or town gas. As this gas contained a significant amount of carbon monoxide it was quite toxic. Most town gas was also odorized, if it did not have its own odor. Modern 'natural gas' used in homes is far less toxic, and has a
mercaptan
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl gro ...
added to it for odor for identifying leaks.
Various names are used for producer gas, air gas and water gas generally depending on the fuel source, process or end use including:
* Air gas: a.k.a. “power gas,” “generator gas” or “Siemens’ producer gas.” Produced from various fuels by partial combustion with air. Air gas consists principally of carbon monoxide with nitrogen from the air used and a small amount of hydrogen. This term is not commonly used, and tends to be used synonymously with wood gas.
* Producer gas: Air gas modified by simultaneous injection of water or steam to maintain a constant temperature and obtain a higher heat content gas by enrichment of air gas with H. Current usage often includes air gas.
* Semi-water gas: Producer gas.
* Blue water-gas: Air, water or producer gas produced from clean fuels such as coke, charcoal and anthracite which contain insufficient hydrocarbon impurities for use as illuminating gas. Blue gas burns with a blue flame and does not produce light except when used with a Welsbach
gas mantle
A Coleman white gas lantern mantle glowing at full brightness
An incandescent gas mantle, gas mantle or Welsbach mantle is a device for generating incandescent bright white light when heated by a flame. The name refers to its original heat sou ...
.
* Lowe’s Water Gas: Water gas with a secondary pyrolysis reactor to introduce hydrocarbon gasses for illuminating purposes.
* Carburetted gas: Any gas produced by a process similar to Lowe’s in which hydrocarbons are added for illumination purposes.
* Wood gas: produced from wood by partial combustion. Sometimes used in a gasifier to power cars with ordinary internal combustion engines.
Other similar fuel gasses
* Coal Gas or Illuminating gas: Produced from coal by distillation.
* Water gas: Produced by injection of steam into fuel preheated by combustion with air. The reaction is endothermic so the fuel must be continually re-heated to keep the reaction going. This was usually done by alternating the steam with an air stream. This name is sometimes used incorrectly when describing carburetted blue water gas simply as blue water gas.
* Coke Oven Gas: Coke ovens give off a gas exactly similar to illuminating gas, part of which is used to heat the coal. There may be a large excess, however, which is used for industrial purposes after it has been purified.
*
syngas, or synthesis gas: (from synthetic gas or synthesis gas) can be applied to any of the above gasses, but generally refers modern industrial processes, such as natural gas reforming, hydrogen production, and processes for synthetic production of methane and other hydrocarbons.
* City (Town) gas: any of the above-manufactured gases including producer gas containing sufficient hydrocarbons to produce a bright flame for illumination purposes, originally produced from coal, for sale to consumers and municipalities.
Uses and Advantages of Producer Gas:
* It is used in furnace. When furnaces are big, no scrubbing etc. is required. When furnace is small, scrubbing is necessary to avoid chocking of small burners. In gas engines, it is used after scrubbing.
* There is no loss due to smoke and convection current.
* Quantity of air required for the combustion of producer gas is not much above the theoretical quantity while burning solid fuel far more than theoretical quantity is required. So in case of solid fuels, the larger quantity of exhaust gases takes away sensible heat and thus there is loss of heat.
* Producer gas is more easily transmitted than solid fuel.
* Gas-fired furnaces can be maintained at a constant temperature.
* With gas, an oxidising and reducing flame can be obtained.
* Heat loss due to converting solid fuel into producer gas can be made in an economic way,
* Smoke nuisance can be avoided.
* Producer gas can be produced even by the poorest quality of fuel.
See also
*
Fuel gas
Fuel gas is any one of a number of fuels that under ordinary conditions are gaseous. Most fuel gases are composed of hydrocarbons (such as methane or propane), hydrogen, carbon monoxide, or mixtures thereof. Such gases are sources energy t ...
*
Gasification
Gasification is a process that converts biomass- or fossil fuel-based carbonaceous materials into gases, including as the largest fractions: nitrogen (N2), carbon monoxide (CO), hydrogen (H2), and carbon dioxide (). This is achieved by reacting ...
*
Gasifier
Gasification is a process that converts biomass- or fossil fuel-based carbonaceous materials into gases, including as the largest fractions: nitrogen (N2), carbon monoxide (CO), hydrogen (H2), and carbon dioxide (). This is achieved by reactin ...
*
History of manufactured gas
The history of gaseous fuel, important for lighting, heating, and cooking purposes throughout most of the 19th century and the first half of the 20th century, began with the development of analytical and pneumatic chemistry in the 18th century. ...
*
Pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
*
Water gas
Water gas is a kind of fuel gas, a mixture of carbon monoxide and hydrogen. It is produced by "alternately hot blowing a fuel layer okewith air and gasifying it with steam". The caloric yield of this is about 10% of a modern syngas plant. F ...
*
Wood gas
Wood gas is a fuel gas that can be used for furnaces, stoves, and vehicles. During the production process, biomass or related carbon-containing materials are gasified within the oxygen-limited environment of a wood gas generator to produce a c ...
References
* Mellor, J.W., ''Intermediate Inorganic Chemistry'', Longmans, Green and Co., 1941, page 211
* Adlam, G.H.J. and Price, L.S., ''A Higher School Certificate Inorganic Chemistry'', John Murray, 1944, page 309
External links
Paxman Suction Gas Producers
{{DEFAULTSORT:Producer Gas
Fuel gas
Industrial gases