Földgáz - A környezetkímélő energia forrása
What is natural gas?
Natural gas is a colourless, odourless gas, which is flammable, and a considerable amount of energy can be gained by burning it. The flue of natural gas is predominantly CO2 and water and beyond this it only contains a minimal amount of burnt pollutants.
It was created in the course of millions of years under the land and the deep seas by means of the decomposition product of organic matters. It wandered under the surface into the fields bordered by cover rocks through the cracks of the rock. These large fields consisting of porous rocks – sand stone, limestone with a loose construction – can be found in a range from some metres below the surface down to the depths of more than 5 000 metres. Here natural gas pressure exceeds even 300 bars while its temperature exceeds 180 °C in some cases, depending on the depth of the deposit.
Natural gas can mostly be found in crude oil deposits but deposits containing only natural gas are not rare, either. It can often be found in sedimentary rocks but sometimes even in volcanic rock, too.
Natural gas is the mixture of hydrocarbon based inflammable gases. Its largest part is methane and the rest is made up of hydrocarbons with a higher C-number, which is ethane, propane, butane, etc., as well as so-called inert gases (CO2, N2). Approximately 10 m3 air is necessary for burning a unit (1 m3) of natural gas, and in the course of its ideal combustion no smoke, soot or ash is generated.
| Typical the natural gas composition: | |
|---|---|
| Methane (CH4) | 97% |
| Ethane (C2H6) | 0,919% |
| Propane (C3H8) | 0,363% |
| Butane (C4H10) | 0,162% |
| Carbon dioxide (CO2) | 0,527% |
| Oxygen (O2) | 0-0,08% |
| Nitrogen (N2) | 0,936% |
| Noble gases (A, He, Ne, Xe) | trace element |
After the natural gas is brought to the surface it is cleaned from the pollutants, such as: water, other gases, crude oil related pollutants and mechanical pollutants so that the quality according to the standards can be attained.
After cleaning (gas preparation) the natural gas gets to the national natural gas transmission systems typically through a large diameter international gas transmission system or to a smaller extent in a liquid state by means of special tankers, then to the consumers through the gas distribution pipelines with the involvement of natural gas traders. The most important benefit of natural gas as an energy source in comparison to electricity is that its transportation to great distances is much more efficient (less network loss), and it can also be stored.