The science of LNG – Liquefied Natural Gas

Liquefied Natural Gas or LNG as it is known is a product which is made of near 100 per cent methane and is converted from its original form into a liquid for storage reasons.

Properties of LNG

One of the benefits of LNG is that it reduces the volume of the gas by 600 times and so is easier to transport, while is also odourless, colourless and non corrosive.

This liquefaction process is one which purifies the energy medium for use as energy. The process gets rid of impurities such as dust, water, helium and other heavy hydrocarbons. This gas is then purified at atmospheric pressure and condensed into a liquid at a very low temperature of minus 162 degrees Celsius. This creates the LNG we use and is made of around 90 percent, with a small mixture of other gases mixed in.

LNG Transportation

LNG is not as dense as water, which weighs in at 1KG/L and is in fact between 0.41KG/L to 0.5KG/L. This creates a variation in heating value of the gas. The energy density is approximately the same as propane or ethanol at around 60 percent of diesel and less still than that of petrol, and is around 70 percent the value of the fuel. Gas with a higher energy density is cheaper to transport as there is a higher energy density to the amount of space needed - this determines production costs. This production cost has a knock-on effect on business electricity rates and gas rates as you will see below.

Gas in this liquid form is a lot easier to transport than in its traditional form and so is much more cost effective a fuel. This gas is fitted into a smaller area such as pipe, lorry, or by boat if no pipe exists. These sea vessels cryogenically freeze the gas to transport it, before it is reheated and turned back into a usable format at the destination point for usage in businesses. This procedure increases business electricity rates and gas rates.

This decrease in the size of the gas makes it much more cost effective to transfer as now it can be fitted in to a smaller area such as a pipe, lorry or if over sea where no pipe exists by a cryogenically frozen sea vessel. When the gas gets to an area it is reheated and turned back into gas in its usable form.

Production

The production of gas happens all over the world, yet it is Qatar and other areas in the Middle East that produce the most LNG. The most important piece of infrastructure to produce the LNG is the plant which needs an LNG train. The largest of these trains is currently in Qatar, with the second largest is in Trinidad and Tobago and the third in Egypt. These plants usually are connected directly to independent plants in the surrounding area. There has been a huge growth of these plants worldwide due to lowering in costs of production in the last few years, ironic with the rate of business energy rates.

This factor alongside the increasing costs of oil has seen a large rise in the amount of this form of gas in production around the world. LNG has also followed those of oil prices since 2003 - a far cry from the buyer's market of the 1990s. Receiving terminals for the product currently exist in 18 countries, 18 countries, including India, Japan, Korea, Taiwan, China, Belgium, Spain, Italy, France, the UK, the US, Chile, and the Dominican Republic and there are plans for many more to receive these facilities.