Butane

Wikipedia:

Butane is a gas with the formula C10 that is an alkane with four carbon atoms. The term may refer to either of two structural isomers, -butane or isobutane (or "methylpropane"), or to a mixture of these isomers. In the IUPAC nomenclature, however, "butane" refers only to the -butane isomer (which is the isomer with the unbranched structure). Butanes are highly flammable, colorless, easily liquefied gases. The name butane comes from the roots but- (from butyric acid) and -ane.

Isomers

Rotation about the central C-C bond produces two different conformations (trans and gauche) for -butane.

Reactions

When oxygen is plentiful, butane burns to form carbon dioxide and water vapor; when oxygen is limited, carbon (soot) or carbon monoxide may also be formed.

The maximum adiabatic flame temperature of butane with air is 2,243 K (1,970 °C; 3,578 °F).

-Butane is the feedstock for DuPont's catalytic process for the preparation of maleic anhydride:

-Butane, like all hydrocarbons, undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing bond dissociation energies, 425 and 411 kJ/mol for the two types of C-H bonds. The two central carbon atoms have the slightly weaker C-H bonds.

Uses

The most common use of butane is as lighter fuel for a common lighter or butane torch.

Butane gas is sold bottled as a fuel for cooking and camping. When blended with propane and other hydrocarbons, it is referred to commercially as LPG, for liquified petroleum gas. It is also used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants.

Very pure forms of butane, especially isobutane, can be used as refrigerants and have largely replaced the ozone layer-depleting halomethanes, for instance in household refrigerators and freezers. The system operating pressure for butane is lower than for the halomethanes, such as R-12, so R-12 systems such as in automotive air conditioning systems, when converted to butane will not function optimally.

Cordless hair irons are usually powered by butane cartridges.

Effects and health issues

Inhalation of butane can cause euphoria, drowsiness, narcosis, asphyxia, cardiac arrhythmia, temporary memory loss and frostbite, which can result in death from asphyxiation and ventricular fibrillation. Butane is the most commonly misused volatile substance in the UK, and was the cause of 52% of "solvent related" deaths in 2000. By spraying butane directly into the throat, the jet of fluid can cool rapidly to −20 °C by expansion, causing prolonged laryngospasm. "Sudden sniffer's death" syndrome, first described by Bass in 1970, is the most common single cause of "solvent related" death, resulting in 55% of known fatal cases.

The paper "Emission of nitrogen dioxide from butane gas heaters and stoves indoors", from the American Journal of Applied Sciences, indicates that nitrogen dioxide, a toxic gas, results from burning butane gas, and represents a human health hazard from home heaters and stoves.