LNG - Zip-Tech Group

Go to content

Main menu:


Zip-Tech Energy
LNG is liquefied natural gas, a clear, colourless, non-toxic liquid that forms when natural gas is subjected to cooled condition to -1620C (-2600F). This process reduce the volume of the gas 600 times, therefore making it easier to store and transport e.g. by lorry tankers, ships to energy-hungry towns and cities overseas. Although, it can be very transported by pipe, but in some cases, pipeline construction may be too expensive or technically challenging. To solve this transportation problem, the natural gas liquefaction technique was developed so that liquefied natural gas (LNG) may be shipped by special tankers.

Natural gas is a fossil fuel derived from the slow transformation of plant and animal organic matter deposited on the seabed and other geologically suitable structures. Over the millennia, these materials were subjected to high temperatures and pressures, and converted by various processes:-
    • Chemical
    • Heat and
    • Pressure
into gaseous hydrocarbons. Sometime the formation may yield both gas and solid hydrocarbon. They are available today in two forms: liquid (oil) and gaseous (natural gas).

Because oil and natural gas usually have a common origin, exploration and production are often conducted jointly in the same deposits. It consists of 90% methane (CH4), 5 to 10% ethane, and less than 1% other hydrocarbons such as butane and propane. It may also contain inert gases, including nitrogen and carbon dioxide, plus very small quantities of trace elements

The natural gas liquefaction process is the procedure carried in turning the gas into liquid by cooling the gas down to a temperature of -160 degrees Celsius, at normal atmospheric pressure. This process transforms the gas, and changes its state to liquid, reducing its volume by a factor of 600, thus enabling transport of larger quantities of product globally.

Contrary to compressed natural gas coming directly by pipeline from production areas (e.g. Algeria and Russia), LNG is almost pure methane, since its other components are removed in the liquefaction process:-
    • Carbon dioxide must be removed beforehand because it would damage the liquefaction units by solidifying inside. It is generally considered as waste.
    • Hydrocarbons that are heavier than methane (ethane, butane, propane) are recovered and sold as raw material or as fuel to the petrochemical industry.
    • Helium is a by-product of substantial commercial value

LNG is highly combustible it does not burn itself, it needs to be in vaporized form and mixed with oxygen air before it burns .Is combustible in the range of 5% to 15% volume concentrations with oxygen. Combustible mixtures in confined space will burn explosively.

LNG is a cryogenic substance and physical contact or spillage constitutes a personnel and equipment hazard. Natural gas presents an asphyxiation hazard. Its main component is methane. It gasifies violently when directly introduced into a cargo tank at ambient temperature, rapidly increases the internal pressure of the cargo tank and makes the atmosphere into a flammable condition.
LNG Key Facts
LNG currently accounts for more than 35% of international trade in natural gas, with increasing demand, growing constantly. The success of LNG is due to its flexibility compared to pipeline transportation:-
    • LNG tankers can sail to many receiving terminals, conversely a receiving terminal can accommodate ships from different countries.

To date, the LNG industry Worldwide comprises of:-
    • 25 LNG production terminals - 89 liquefaction trains are in operation in 18 countries on five continents. Qatar is the world leader in LNG production, ahead of Indonesia, Malaysia, Australia and Trinidad & Tobago. The total annual production capacity of LNG reached 282 million tons a year in 2012.
    • 93 LNG receiving terminals and regasification plants in 26 countries on four continents. In 2012, the global LNG import market was 236 million tons. Japan, Korea and Spain are the leading importers of LNG. The overall regasification capacity was 668 million tons a year at the end of 201
    • Currently, 378 LNG tankers are in service worldwide. Their total transport capacity is 53.7 million cubic meters and growing

What is LNG?
LNG is natural gas that has been cryogenically cooled to liquid state.
It is the same gas or methane that is piped throughout the UK for domestic use but, by cryogenically cooling the gas to -162°C, its volume is reduced making it easier to store helping to deliver a cleaner future.

LPG & CNG (www.ztenig.com)
On a cycle representing congested urban traffic, both LPG and CNG outperform petrol powered vehicles on emissions of carbon monoxide (CO). Indeed, emissions of CO from CNG powered vehicles are of the same order as those emitted by diesel vehicles. However, emissions of total hydrocarbons (THC) from CNG vehicles are relatively high because of methane, the major component of natural gas. Although methane is a small contributor to the formation of low level ozone it is a major factor in global warming. Emissions of NOx and particulates from both LPG and CNG powered vehicles are significantly lower than those from diesel vehicles. Moreover, emissions of NOx from CNG vehicles are half those from equivalent petrol engined vehicles. A recent study using a small delivery van fitted with a three way catalyst and capable of switching between CNG and petrol, showed that on a modified EU emission test cycle, emissions of CO, non-methane hydrocarbons (NMHC) and NOx were 76%, 88% and 83% respectively lower with CNG than with petrol. Using data from other studies CNG also compares favourably with emissions from equivalent sized diesel-engine vehicles

Back to content | Back to main menu