What is Compressed Natural Gas (GNC)?




 What is Compressed Natural Gas CNG?

Compressed natural gas is a simple mixture of gases, known by the acronym CNG. It is a fuel for vehicular use that is economical and environmentally clean. It´s considered a sustainable alternative for replacing liquid fuels. The terms compressed natural gas and vehicular natural gas (CNG) are equally used. 


CNG is essentially natural gas stored at high pressures, usually between 200 and 250 bar, according to the regulations of each country. This natural gas is mostly methane, which contains a high rate of hydrogen by carbon (4), it produces less CO2 per unit of energy delivered, compared to other higher hydrocarbons (with more carbon atoms and a minor radius H / C) . 

It is difficult to establish clearly the characteristics of existing CNG in the market considering that  its composition varies depending on the site of where it is extracted and the subsequent treatment that gives the gas company. 

The following table summarizes the average values ​​obtained from different sources.

Propiedad Gas Natural
Mani component CH4 (~90%) 
Tª of boiling at 1 atm (ºC) -160ºC 
Specigic weight 0,808 
Liquid phase density  (kg/l) 0,423 (*)  
calorific value (kcal/kg) 1.990 
Octane index 115
Density relative to air  0,625 

 (*) At the boiling point

Source Utilización del gas natural en vehículos de transporte público. Javier Barrentos Calero. 2005