Liquefied petroleum gas (LPG) and Liquefied natural gas (LNG) are often confused with each other. LPG consists chiefly of propane (C3H8) and butane (C4H10), and is used mainly in domestic and commercial applications (such as fuel for cars). LPG is liquefied by holding it under high pressure. LNG, by contrast, is a liquid at atmospheric pressure but at a very low temperature (approx. – 162° C). LPG’s specific gravity is also totally different from LNG’s: LPG’s components are heavier than air and the gas does not disperse if it escapes. LNG (natural gas), by contrast, is lighter than air and disperses and rarefies very quickly into a mixture that is no longer flammable.
The storage of LPG is at a high pressure, unlike the storage of LNG which is at low temperature, and thus requires the use of very different equipment (other material properties, thicknesses, insulation) and standards.
LNG arrives at the terminal by ship, is unloaded and stored in tanks, warmed (or regasified) and then delivered to the gas transport network. At this point, its use is identical to that of conventional natural gas. The LNG can be distributed (loaded) by truck and ship as well.
LNG arrives at the terminal by ship, is unloaded and stored in tanks, warmed (or regasified) and then delivered to the gas transport network. At this point, its use is identical to that of conventional natural gas. The LNG can be distributed (loaded) by truck and ship as well.
The ships in which LNG is transported have double hulls so that the risk of leakage during a collision is minimal. Should this happen in an extreme condition, and LNG escapes into the water, then the cold liquid will immediately heat up due to the ambient temperature and the warmer water and the resulting gas cloud will rise and disperse. The LNG will not dissolve or mix with water, but disappear as gas because it is lighter than air. A cloud will be visible around the leakage; this is not a gas cloud, but condensing water vapour due to the cold that is released from the LNG. The flammable natural gas has already risen up out of this.
From the moment the LNG is regasified, the environmental impact is identical to that of natural gas (e.g. fewer CO2 emissions on combustion in comparison with coal). If there is direct environmental exposure, for example through leakage, LNG causes less damage than an oil spill since it will immediately vaporize into the atmosphere.
LNG is liquefied natural gas; it is therefore, like natural gas from the gas network, the cleanest fossil fuel available. When using LNG as fuel in small-scale applications, such as transport or for isolated industry, less CO2 is therefore emitted than with oil products, virtually no nitrogen and fine dust, and it is a Sulphur-free fuel. It is thus an affordable and cleaner alternative to oil products.
Pakistan Onshore LNG is an independent operator. This means that players in the gas market can contract throughput capacity in the terminal. They will do so largely under long-term contracts for substantial volumes of gas each year. Off-takers will be energy companies and also producers that sell their own products.
Pakistan Onshore LNG will have a commercial interest in the trade in or sale of LNG or natural gas. As independent companies they will offer their services to anyone wishing to use them. Pakistan Onshore LNG will give all customers a fair chance to use the independent LNG terminal by means of an open season procedure.
It does not take any extra energy. The LNG is converted back into a gas in a heat exchanger. Such a heat exchanger is actually a heating radiator in reverse: the LNG is passed through the radiator (heat exchanger) and, by increasing the surface area, it absorbs heat from the surrounding air via the metal.
LNG is a colourless, non-flammable liquid. It is not toxic or poisonous and has no odour. It is so cold that it cannot combust. If it evaporates and turns back into a gas, is it like natural gas from a gas cooker; it can only combust with the right air-gas ratio and a source of ignition.
LNG will evaporate immediately because it heats up due to its surroundings. It does not mix with water, will not float and cannot be absorbed into the ground. Before it can combust, it must first evaporate and the LNG-air ratio must be just right; i.e. 5-10% of the air must be made up of natural gas. If there is too much or too little natural gas, it is non-flammable. Whether or not this ratio is good depends, among other things, on the weather; if it is windy, natural gas disperses and there will not be a inflamable ratio. Moreover, there must also be a source to ignite it. LNG will never spontaneously combust.
LNG as a fuel has positive effects on the environment and health. With the combustion of natural gas, a lot less fine dust, nitrogen, sulphur and other emissions are released. The use of LNG instead of oil-based fuels reduces CO2 emissions by up to 20%, SO2 by 100%, NOx by almost 90% and fine dust.
Gas-fired engines using LNG are quieter than diesel engines; the difference is so great that trucks running on LNG can be used at night for distribution where trucks are now only allowed during the day to prevent noise nuisance.
Gas-fired engines using LNG are quieter than diesel engines; the difference is so great that trucks running on LNG can be used at night for distribution where trucks are now only allowed during the day to prevent noise nuisance.
Significant cost savings can be achieved on fuel consumption in ships because 80% of the operational costs of a ship consists of fuel costs. LNG can be a cheaper and is a cleaner fuel.
No. Globally, 15 million cars already run on natural gas; in China and the US, thousands of trucks use LNG. In Pakistan, companies are interested in introducing this concept.
Yes, the use of LNG as transport fuel is definitely safe. It is already a long-accepted fuel throughout the world for use in trucks, cars and ships. Industry has built up an excellent safety reputation in the more than 50 years that LNG has been used.
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