Editing Compressed natural gas (section)

{{Short description|Fuel gas mainly composed of methane}}
{{Use British English|date=February 2021}}
{{Redirect|CNG}}
{{distinguish|liquefied natural gas}}<!--As explained herein at [[#Comparison with other natural gas fuels]]-->
{{distinguish|text=[[autogas]] nor with [[gasoline]] (petrol)}}
'''Compressed natural gas''' ('''CNG''') is a [[fuel gas]] mainly composed of [[methane]] (CH<sub>4</sub>), [[Gas compression|compressed]] to less than 1% of the volume it occupies at [[standard atmospheric pressure]]. It is stored and distributed in hard containers at a pressure of {{Convert|20|-|25|MPa|psi+bar|}}, usually in [[Cylinder|cylindrical]] or [[Sphere|spherical]] shapes.

CNG is used in traditional petrol/[[internal combustion engine]] vehicles that have been modified, or in vehicles specifically manufactured for CNG use: either alone (dedicated), with a segregated liquid fuel system to extend range (dual fuel), or in conjunction with another fuel ([[Bi-fuel vehicle|bi-fuel]]). It can be used in place of [[gasoline|petrol]], [[diesel fuel]], and [[liquefied petroleum gas]] (LPG). CNG combustion produces fewer undesirable gases than the aforementioned fuels. In comparison to other fuels, [[natural gas]] poses less of a threat in the event of a [[Oil spill|spill]], because it is lighter than air and disperses quickly when released. [[Renewable natural gas|Biomethane]], [[biogas]] from [[anaerobic digestion]] or [[landfill]], can be used.

In response to high [[fuel]] prices and environmental concerns, CNG has been used in [[auto rickshaw]]s, [[pickup truck]]s, [[transit bus|transit]] and [[school bus]]es, and [[train]]s.

The cost and placement of fuel storage containers is the major barrier to wider/quicker adoption of CNG as a fuel. It is also why municipal government, public transportation vehicles were the most visible early adopters of it, as they can more quickly amortize the money invested in the new (and usually cheaper) fuel. In spite of these circumstances, the number of vehicles in the world using CNG has grown steadily (30 percent per year).<ref>{{Cite web |url=http://www.cgmum.co.in/GNC.pdf |title=Market Studies Series, GNC |publisher=Consulate of the Argentinian Republic, Mumbai, 2009, in Spanish |access-date=2011-01-03 |archive-date=2012-06-27 |archive-url=https://web.archive.org/web/20120627205348/http://www.cgmum.co.in/GNC.pdf |url-status=dead }}</ref> Now, as a result of the industry's steady growth, the cost of such fuel storage [[Gas cylinder|cylinders]] has been brought down to a much more acceptable level. Especially, for the [[Gas_cylinder#Types|CNG Type 1 and Type 2 cylinder]]s, many countries are able to make reliable and cost effective cylinders for conversion need.<ref>{{Cite web|url=http://www.zafirotech.net/index.php/road-transport/natural-gas-vehicle-cng/ |title= About natural gas vehicle (CNG as an auto fuel) | website = Zafiro Tech|access-date=2013-12-14 |url-status=dead |archive-url=https://web.archive.org/web/20131214180334/http://www.zafirotech.net/index.php/road-transport/natural-gas-vehicle-cng/ |archive-date=2013-12-14}}</ref>