What is LNG?

Natural gas, the cleanest-burning hydrocarbon, is a major source of energy. But many energy-hungry places are located far from gas fields, making pipelines too impractical or costly to build. But if you cool natural gas to make a liquid, you shrink its volume and make it easier and safer to store and shipping.

A typical LNG process. The gas is first extracted and transported to a processing plant where it is purified by removing any condensates such as water, oil, mud, as well as other gases such as CO₂ and H₂S. An LNG process train will also typically be designed to remove trace amounts of mercury from the gas stream to prevent mercury amalgamizing with aluminium in the cryogenic heat exchangers. The gas is then cooled down in stages until it is liquefied. LNG is finally stored in storage tanks and can be loaded and shipped.

What is LNG and how can we use it?

LNG is a clear, colourless, and non-toxic liquid which forms when natural gas is cooled to -162ºC (-260ºF). The cooling process shrinks the volume of the gas 600 times, making it easier and safer to store and ship. In its liquid state, LNG will not ignite.

When LNG reaches its destination, it is turned back into a gas at regasification plants. It is then piped to homes, businesses, and industries where it is burnt for heat or to generate electricity. LNG is now also emerging as a cost-competitive and cleaner fuel, especially for shipping heavy-duty road transport.

Fuelling a growing market with LNG

LNG is rapidly playing a bigger role in the energy mix, and the market for it is expected to grow at around 5% annually. Global demand could increase from about 240 million tonnes per annum (mtpa) to around 430 mtpa in 2025. For comparison, just 80,000 tonnes of LNG were shipped in 1964, the first year of the LNG trade.

Qatar’s expansion was an act of sheer audacity. Qatar tripled its LNG production capacity to over 80 million metric tons a year — about 11 billion cubic feet a day — leaping past Malaysia and Indonesia as the world’s largest LNG maker. Last year Qatari plants exported almost one-third of the LNG traded across the globe. In the mid-2000s, with construction under way, Qatari officials thought they’d be selling much of their LNG to the United States. The Lower 48 shale-gas boom blew apart that plan. But last year, as Japan idled nuclear power production after the Fukushima disaster, Qatari exports to Japan soared 56 percent over their 2010 level, according to the BP Statistical Review of World Energy. That dulled Qatar’s pain of losing the U.S. market.