Fuel gas is any one of a number of

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy bu ...

s that under ordinary conditions are gaseous. Most fuel gases are composed of

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

s (such as methane or propane),

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 ...

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 si ...

, or mixtures thereof. Such gases are sources

energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...

that can be readily transmitted and distributed through pipes. Fuel gas is contrasted with liquid fuels and from solid fuels, although some fuel gases are liquefied for storage or transport (for example, autogas). While their gaseous nature has advantages, avoiding the difficulty of transporting solid fuel and the dangers of spillage inherent in liquid fuels, it also has limitation. It is possible for a fuel gas to be undetected and cause gas explosion. For this reason, odorizers are added to most fuel gases. The most common type of fuel gas in current use is

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon ...

Types

There are two broad classes of fuel gases, based not on their chemical composition, but their source and the way they are produced: those found naturally, and those manufactured from other materials.

Manufactured fuel gas

Manufactured fuel gases are those produced by chemical transformations of solids, liquids, or other gases. When obtained from solids, the conversion is referred to as

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 react ...

and the facility is known as a

gasworks A gasworks or gas house is an industrial plant for the production of flammable gas. Many of these have been made redundant in the developed world by the use of natural gas, though they are still used for storage space. Early gasworks Coa ...

. Manufactured fuel gases include: * Coal gas, obtained from pyrolysis of coal * Water gas, largely obsolete, obtained mainly from coke * Producer gas, largely obsolete, obtained mainly from coke * Syngas, major current technology, obtained mainly from

* Wood gas, obtained mainly from

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of ligni ...

, once was popular and of relevance to biofuels *

Biogas Biogas is a mixture of gases, primarily consisting of methane, carbon dioxide and hydrogen sulphide, produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste and food waste. I ...

, obtained from landfills * Blast furnace gas

Well or mine extracted fuel gases

In the 20th century,

, composed primarily of methane, became the dominant source of fuel gas, as instead of having to be manufactured in various processes, it could be extracted from deposits in the earth. Natural gas may be combined with hydrogen to form a mixture known as HCNG. Additional fuel gases obtained from natural gas or

petroleum Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude ...

: * Propane * Butane * Regasified liquefied petroleum gas

Uses

One of the earliest uses was gas lighting, which enabled the widespread adoption of streetlamps and the illumination of buildings in towns. Fuel gas was also used in gas burners, in particular the Bunsen burner used in laboratory settings. It may also be used gas heaters, camping stoves, and even to power vehicles, they have high calorific value. Currently, fuel gases, especially syngas, are used heavily for the production of ammonia for fertilizers and for the preparation of many detergents and specialty chemicals.

References

Industrial gases Synthetic fuel technologies {{Energy-stub