LNG is liquefied natural gas (Liquefied Natural Gas) known as methane (СН4). It is produced by cooling the regular commercial gas to condensation temperature (-161,5°С), as a result it is converted into liquid. The gas reduces its volume by about 600 times without compression, only under effect of low temperature, simultaneously having removed from the impurities that make it more clean and practical as a fuel for using it in any way.
LNG is produced at the so called liquefaction facilities (plants), following which it is transported in special cryogenic tanks that allows to keep the low temperature within the container for a long time (up to 70 days), to the storage station (for long term storage) or to the LNG Regasification local or system station, where it is converted into commercial gas before delivery to the end user.
Consequently, LNG shall not be considered as a different type of fuel. It is rather a physical form of the regular natural gas which storage and transportation technique allows carrying out the so called pipeless gasification and it has undeniable advantages compared over other types of fuel not only to suppliers but also to end users.
CNG is compressed natural gas methane СН4, in liquid state at the very low temperature -161,5°С without compression. When it passes through the atmosphere it very quickly returns to its initial gaseous state, increasing its volume 600 times and evolving the cold. The high-density and low volume allow to store CNG efficiently and transport it over long distances in the cryogenic tanks, as well as to use as a fuel for the high power engines of vehicle of the continued operation or of long distance logistics.
CNG – (compressed) natural gas methane СН4 at pressure of 200-250 bar and which produced at the gas-compressor stations from the commercial gas and most often used as a fuel for the low and medium power engine units. It is the most common form of the natural gas motor fuel. It is stored and transported in special containers maintaining pressure. It is lighter than air, evaporated quickly and not accumulated indoors.
LPG is liquefied petroleum gas (С3Н8, С4Н10 - propane/butane mix, Commercial propane/butane mix), is a product of the oil-associated gas with the boiling temperature from 0 to -40 °С depending on the composition of mixtures, that lays it open to the low winter temperatures. LPG shall be stored in the gas holders or special containers under pressure of up to 1,6 mPa and widely used as a fuel for the vehicle and very seldom for the individual farms (in view of its high cost infrastructure). LPG is heavier than air, it flows along floors and it is a highly flammable and explosive substance. It keeps forward diesel fuel and masut fuel oil, but it is inferior in efficiency and environmental disposal factors as a fuel for the boiler-houses and vehicles to the natural gas.
Many say that gas will help save Astana from the smog and improve the environment. How LNG may influence the situation of critical pollution?
Heavy slurry, ash dust and other combustion products of coal, fuel oil, diesel and hard coal remaining in the city atmosphere in calm weather cause considerable discomfort for the inhabitants and concern of environmentalists. In the framework of the Astana city gasification project, it is possible to significantly reduce the negative impacts on the ecology of all over the city and region.
LNG technology enabling efficient supply of natural gas to consumers in the regions that do not have main gas pipeline, will allow replacing environmentally unfriendly energy resources.
Natural gas (methane) is the most environmentally friendly of the fossil fuels and is currently used worldwide to reduce emissions of carbon dioxide. Compared to coal, natural gas produces much less carbon dioxide and sulfur emissions. Liquefied natural gas has no odor, is colorless, it is not flammable and not explosive, chemically non-toxic, by 75-99% consists of methane.
In the methane molecule one carbon atom is to four hydrogen atoms. Such an optimal ratio of these elements is not observed in any one of the remaining hydrocarbons. In the case of natural gas, which is composed of methane, this means that when generating one unit of energy, less carbon dioxide is emitted than from the other energy sources. So, in propane, one atom of carbon is to 2.7 atoms of hydrogen; in fuel oil, this value is even smaller.
The worst indicator of carbon dioxide is observed at direct combustion of brown coal: for each generated unit of energy, about twice as much greenhouse gases are emitted than in the case of natural gas. Even the cleanest coal technologies produce 70 percent more life cycle greenhouse gas emissions than electricity generated based on regasified LNG.