Is LNG active

What is LNG? What is CNG What is LPG?

Compressed Natural Gas (CNG)is the name of the compressed natural gas methane. The chemical formula of the hydrocarbon is CH4, the combustion produces CO2 and water (H20). Due to the relatively high hydrogen content, less carbon dioxide is produced when it is used than with diesel fuel, for example. However, methane is also primarily obtained from fossil sources, but it can also be produced from biological waste and is then usually referred to as "biogas". Methane is lighter than air and evaporates quickly. In principle, entry into underground garages and the like is therefore also permitted. The myth that gas vehicles are generally not allowed to enter garages actually only applies to LPG vehicles (see below). However, old signs with the words "Gas vehicles prohibited" can still be seen at some of the garage entrances. Even if this does not actually mean CNG vehicles, entry could be a problem from a legal point of view, as such a formulation does not differentiate further between LPG and CNG.

Liquefied Natural Gas (LNG) is also methane, but it is liquefied by cooling it to temperatures between –161 and –164 degrees Celsius. High amounts of energy are required for this, but the gas is extremely compact and also easier to transport, for example in tankers or vehicles. In its liquid state, methane only requires around 1/600 of the volume. However, if the LNG is no longer actively cooled, it slowly evaporates again and the corresponding pressure builds up in the tank, which after a while leads to the gas having to be released. To slow down this process, the LNG tanks in the vehicle are thermally insulated. Nevertheless, the LNG can only be stored in the vehicle tank for a few days without active cooling.

Despite the energy losses through the liquefaction process, LNG can make ecological sense. Natural gas is often simply burned off as a by-product of crude oil production due to the lack of transport options. Here, deep-freezing and transport to the consumer naturally appear to be more sensible, especially since transport involves fewer environmental risks than is the case with liquid fuels: In the event of a tanker accident with LNG, the environmental damage would be manageable, after all, the gas volatilizes at normal temperatures and thus does not get there into the ground and does not form an oil slick on the water. Methane itself is considered to be extremely harmful to the climate, but it is very clean when burned. There is almost no fine dust and, due to the high hydrogen content, less CO2 is released than when burning petrol or diesel. As with all raw materials and energy sources, the decisive factor is where the methane comes from. If, for example, the gas is extracted at great expense through "fracking", a type of hydraulic blasting of the rock at great depth, the ecological balance is rather negative: The process requires large amounts of water and is criticized for endangering or even with the groundwater To pollute chemicals.
Otherwise there is still the possibility of extraction in the context of crude oil production and conventional gas production. Another source of LNG is biogas. The extraction from biological waste is of particular interest here. Alternatively, biomethane could also be obtained from agricultural crops. Here, however, critics point out the large space requirement, which also competes with food production, as well as the high energy consumption in production.

Liquefied Petroleum Gas (LPG) In addition to being used in gas cartridges for camping stoves and the like, it was or is often to be found as a fuel for cars in south-eastern Turkey. It is sometimes also traded under the name "LPG". The technology for use can be retrofitted relatively easily in gasoline vehicles and cars can be operated bivalent, i.e. with gas or gasoline, using a simple switch. LPG itself is liquefied propane or butane gas that is produced as a waste product in oil and natural gas production or in the refinery. With low pressure, the gas can be liquefied relatively easily, even at room temperature, reducing the volume by a factor of 260.
In Austria, LPG never really caught on as a vehicle fuel. It is heavier than air and therefore it is forbidden to drive into underground garages, as a “gas lake” could form there if there is a leak. In the commercial vehicle sector, LPG had a high phase in the MAN buses operated by Wiener Linien, but this was over with the introduction of the Euro 6 emissions class. Wiener Linien is now running on diesel again and in some cases, in inner-city areas, also electrically.