What is the difference between LNG and LPG?

LNG (Liquefied Natural Gas) and LPG (Liquefied Petroleum Gas) are often confused with each other and wrongly used interchangeably: often, LNG is meant when LPG is referred to. And yet these are two completely different products with different characteristics and requirement specifications.

LPG is a by-product of the refining process and thus a mineral oil product that consists mainly of propane (C3H8) and butane (C4H10). It is mainly used in domestic and commercial applications (such as fuel for cars). LPG is liquefied under high pressure.

LNG, on the other hand, is a natural gas product which mainly consists of methane. It liquefies when cooled to about -162°C and at atmospheric pressure. The relative density of both products is also different: the components of LPG are heavier than air, i.e. the gas does not disperse when it escapes, and is therefore flammable which means that it has a different hazardous potential. LNG (natural gas), on the other hand, is lighter than air, and spreads and dilutes quickly into a mixture that is no longer flammable.

LPG is stored at high pressure whereas LNG is stored at low temperature and thus requires the use of completely different technical equipment (different material properties, thickness and insulation) and a different product standard.

How is LNG stored?

LNG is stored in specially designed, completely insulated full containment tanks. A full containment tank consists of a metal inner tank and a concrete outer tank. The thermal insulation between the steel inner tank and the concrete outer tank limits the heating up of LNG and thereby limits the evaporation (so-called boil off gas) of LNG.

What is LNG’s impact on the environment and the climate?

Compared to conventional oil-based fuels, the use of LNG as a marine and HGV fuel generates no fine particles or sulphur dioxide (SOx) and produces up to 85% less nitrogen oxide (NOx). Particularly in the shipping sector, the use of LNG as fuel can make a significant contribution to improving air quality in port cities, coastal regions and along inland waterways.

LNG can also to help reduce greenhouse (GHG) gas emissions by up to 20% (with an optimised supply chain). However, the choice of fuel is only one factor regarding the reduction of greenhouse gas (GHG) emissions in the mobility sector. Improving energy efficiency or reducing travel speed can also contribute to reducing GHG emissions.

If LNG is used as an alternative to pipeline gas, it must be regasified by heating. As regasified LNG, it is fed into the gas transmission network and then has the same environmental impact as pipeline gas. This means that, in comparison to coal, regasified LNG emits less CO2 during combustion. Generally, natural gas is the fossil fuel with the lowest CO2 emissions. If directly exposed to the environment, e.g. due to a leak, LNG causes less damage than an oil spill because it evaporates immediately into the atmosphere.

In the medium to long term, the power-to-gas technology will allow the production of synthetic LNG which is CO2–neutral. The MENA (Middle East, North Africa) region offers great potential for the establishment of power-to-gas production sites. There, the synthetic gas would be liquefied and transported by ship as synthetic LNG. It would be possible to import synthetic LNG into Germany via the LNG terminal in Brunsbuettel.

The issue of methane emissions (methane slip) is constantly brought up in connection with LNG, leading to the criticism of LNG. What is this exactly?

The main component of fossil LNG is methane (CH4) which is more harmful to the environment than COif it enters the atmosphere unburned. These methane emissions (also known as methane slip) can occur along the entire LNG supply chain, i.e. during extraction, liquefaction and transport as well as when used in engines. Each of these steps along the LNG supply chain as well as the type of engine must be considered when quantifying methane emissions. Specifically, this includes the extraction site, the degree of innovation of the liquefaction plant, the type of transport, the transport route and the type of engine (two- or four-stroke, dual fuel or LNG only engine).

Therefore, these factors need to be assessed before we can make a statement about methane emissions. As a result, it is not possible to make generalised and comparable statements about the extent of methane emissions and therefore about the potential for reducing greenhouse gas emissions when using fossil LNG. It is only possible to make meaningful and reliable statements about specific production sites, delivery routes and engines.

How does the industry deal with this problem? What exactly is being done to reduce methane emissions?

The industry takes this problem very seriously. It undertakes a series of measures to reduce methane emissions and therefore the impact on the environment.

Methane slip in engines is continuously being addressed by engine manufacturers. Modern ship engines running on LNG already emit up to 20% less greenhouse gases. In the future, these engines will also be able to run on synthetically produced LNG, i.e. based on renewable energy, thus offering flexibility and the necessary regulatory compliance with future climate protection regulations.

At the end of 2019, leading shipping associations, including the German Shipowners’ Association (Verband Deutscher Reeder, VDR), announced that they intend to set up an international fund of around €4.5 billion to reduce greenhouse gas emissions from shipping and make shipping more environmentally-friendly in general. The fund will be financed by shipping companies around the world through a mandatory research and development contribution of 2 US dollars per tonne of fuel.

The International Maritime Organisation (IMO) is also working on the implementation of its strategy to reduce greenhouse gas emissions. One of its aims is to include methane as an assessment factor in the life cycle analysis of maritime fuels and alternative sources of energy. Within the framework of the international convention for the prevention of pollution from ships (MARPOL, annex VI), new regulations are being prepared for particles and soot (black carbon) which also adversely affect the climate.

What is an open access, non-discriminatory terminal?

German LNG Terminal is an independent terminal operator. This means that German LNG Terminal is open to all gas market players that are interested to purchase throughput capacity in the terminal. This is mostly organised through long-term contracts for a substantial part of the overall capacity of the LNG terminal. Customers include energy traders, suppliers and producers that sell their own products.

Noise reduction in road freight transport
LNG produces less nitrogen oxide
What is the role of an independent terminal operator?

Neither German LNG Terminal nor its shareholder companies own, produce or trade in LNG or natural gas. As an independent company, German LNG Terminal offers its terminal services at market conditions to any party in the international LNG market wishing to utilise them.

Is LNG dangerous?

LNG is non-toxic, colourless and odourless, and it is non-flammable. Due to its cryogenic state it cannot combust. If it evaporates and turns back into gas, it behaves like natural gas in a gas oven; it only combusts with the right air-gas ratio and a source of ignition.

What happens if LNG escapes?

If LNG escapes- despite the high safety standards – it evaporates immediately because it heats up due to the ambient temperature. It does not mix with water, does 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 to 10% of the air must contain natural gas. If there is too much or too little natural gas, it is non-flammable. Whether or not this ratio is right depends on the weather, among other factors; if it is windy, natural gas disperses and a flammable ratio is not achieved. There must also be a source of ignition. LNG never combusts spontaneously. German LNG Terminal is committed to the highest safety requirements to prevent any possible LNG leakage.
A terminal/location-specific safety policy will be developed which will be in accordance with the highest standards available in the sector.

Is LNG safe to use?

The use of LNG as marine and Heavy Good Vehicle (HGV) fuel is based on a mature and safe technology which has long been used in the mobility sector. LNG has been used as fuel for trucks, cars and ships for over 50 years. The industry has built up an excellent reputation for the safety of use and its compliance with the associated safety standards.

What happens at an LNG import terminal?

LNG arrives at the terminal by ship, is unloaded and temporarily stored in tanks, then partly pressurised and heated in vaporisers (where it is regasified) and then measured and fed into the gas network. At this point, its use is identical to that of conventional natural gas. LNG – in its liquefied state – can also be reloaded and distributed by tank truck, ship and rail ank car.

What would happen if LNG accidentally leaked out from a ship?

LNG carriers are equipped with state-of-the-art safety technology. They have double hulls to ensure minimal risk of leakage in the event of a collision. In the rare event of a collision and of LNG leaking into the water, the cryogenic liquid would warm up immediately due to the ambient temperature and the warmer water and change its aggregate state from liquid to gaseous. The resulting cloud of gas would rise and disperse. LNG does not dissolve or mix with water but rather evaporates into gas and disappears as it is lighter than air. A cloud is visible around the leakage. However, this is not a gas cloud, but condensing water vapour due to the cold that is released from the LNG. The regasified LNG has already risen up out of it.

How can LNG contribute to achieving climate change targets?

LNG is liquefied natural gas, the cleanest fossil fuel available. When using LNG as fuel in small-scale applications, such as in transport or for selected industridal setors, less CO2 is emitted than when using oil products, and virtually no nitrogen or fine dust is generated. It is also a sulphur-free fuel.

LNG can make a (limited) contribution to reducing greenhouse gas emissions in the mobility sector, depending on factors such as the extraction site, the liquefaction plant, the mode and route of transport and the type of engine, etc. By optimising LNG supply chains, greenhouse gas emissions can be reduced by up to 20%. However, the use of LNG — and thus the choice of fuel — is only one measure in a series of actions to increase sustainability in the transport sector.

In the medium to long term, the power-to-gas technology will allow the production of synthetic LNG which is CO2--neutral. The MENA (Middle East, North Africa) region offers great potential for the establishment of power-to-gas production sites. There, the synthetic gas would be liquefied and transported by ship as synthetic LNG. It would be possible to import synthetic LNG into Germany via the LNG terminal at Brunsbuettel.

What role does natural gas play in the energy transition?

As the least pollutant fossil energy source natural gas plays a significant role in the energy transition: gaseous energy, first fossil but increasingly synthetic (and therefore climate-neutral) will continue to contribute to a reliable supply of energy in Germany and Europe once nuclear energy as well as coal have been phased out or are being considerably reduced and our energy needs cannot be solely met by renewable energy alone yet. The German Economic Affairs Ministry has recognised natural gas as a vital transition technology towards a climate-neutral energy supply and therefore as a cornerstone of a successful energy transition.

When used as a marine and HGV (Heavy Good Vehicle) fuel, liquefied natural gas (LNG) offers the possibility of improving local and regional air quality to its low air pollutant emissions (fine particles, SOx, NOx). LNG can also contribute to lowering the greenhouse gas emissions of shipping and heavy goods road transport by up to 20% (with an optimised supply chain).

How much energy is needed to keep LNG liquefied?

None. Once liquefied, LNG simply needs to be kept well insulated so that its cryogenic temperature of approx. -162 °C can be maintained. No further cooling measures are required.

How much energy is needed to convert LNG back into gas for the use in the engine of a ship or truck?

No additional energy is required. LNG is converted back into its gaseous state in a heat exchanger. Such a heat exchanger basically works like a radiator in reverse. The LNG is passed through a heater (heat exchanger) and by increasing its surface area, it absorbs heat from the surrounding air via the metal.

How can LNG be distributed and used for small-scale applications?

LNG can be distributed from Brunsbuettel to smaller terminals, for example in the Baltic region and the Hamburg port area or other ports in Northern Germany. This can be carried out by bunker ships or barges, tank trucks and rail tank cars.

LNG can be used:

  • as marine fuel for sea-going and inland waterway vessels,
  • as fuel for trucks (HGV transport),
  • as a low-emission source of energy for industries which are not connected to the gas network and thereforeoften use oil or propane as a source of energy.
What are the main reasons for using LNG as marine fuel or HGV fuel?

Due to its low air pollutant emissions, the use of LNG as a fuel can contribute significantly to improving air quality. Compared to conventional, oil-based fuels, the use of LNG generates no fine particles or sulphur dioxide (SOx), and produces up to 85% less nitrogen oxide (NOx). Particularly in the shipping sector, the use of LNG as a fuel can make a significant contribution to improving air quality in sea ports, coastal regions and along inland waterways. LNG can also help to reduce greenhouse gas emissions by up to 20% (with an optimised supply chain). LNG-powered engines are also quieter than diesel engines; the difference is so great that LNG-operated trucks are also allowed to drive at night where diesel-powered trucks are only allowed to circulate during the day to avoid noise pollution.

Since 2015, the standards for sulphur emissions in European and American coastal waters have been significantly tightened. Since January 2020, the sulphur content of marine fuels used on the world’s oceans may not exceed 0.5%.

Is the use of LNG as a fuel new? And what’s happening in Germany?

No, the use of LNG as a fuel is not new. In 2019, around 485.1 bn m³ or 345,5 m t of LNG were traded and transported around the world (source: BP, Statistical Review of World Energy, 2020, p. 40–42).

LNG in shipping

Worldwide there are running 469 vessels on LNG yet (source: Alternative Fuels Insight (dnvgl.com), latest access 16.04.2021)

In addition, 30 LNG-bunker vessels are already in operation, 13 more have been ordered and a further 3 ships are LNG-ready, i.e. can be easily converted to an LNG operation (source: Alternative Fuels Insight (dnvgl.com), latest access 16.04.2021).

At present, the classification society DNV assumes that a total of 271 LNG-fuelled ships will be on order and a total of 146 ships will be LNG-ready by 2027.

Alternative Fuels Insight (dnvgl.com), latest access 16.04.2021

A few prominent examples (as of April 2021):

Hapag-Lloyd AG

As per Q1, 2021, Hapag-Lloyd operates the LNG-fuelled “BRUSSELS EXPRESS”. In December 2020 the shipping company has ordered 6 further mega containerships with a capacity of 23,500 TEU each.


The world’s largest LNG-powered container ship, the CMA CGM “Jacques Saade” (23,000 TEU), was launched in September 2019. This is the first vessel in a new fleet of nine LNG-powered container ships to be built by one of the world’s largest maritime shipping company, CMA CGM.

AIDA Cruises

AIDAnova, the first cruise ship in the world to be fuelled with liquefied natural gas, has been in service since 2018. AIDA plans to put two more LNG cruise ships into service by 2023 (2021: AIDAcosma, 2023: name not yet known). The Meyer Werft group is building a total of ten LNG cruise ships for the AIDA parent company, Carnival Corporation, which are to be put into service by 2025 for various cruise brands of the group.

Bunker supplier Nauticor

The LNG bunker supply vessel “Kairos” of the Hamburg-based LNG supplier Nauticor was put into service in February 2019.

The container ship “Wes Amelie” owned by the German shipping company, Wessels Reederei from Haren (Ems), was retrofitted for operation with LNG back in 2017.

On 31 October, 2019, the PitpointLNG, based in Cologne, launched the first inland LNG-fuel station for the fulfilment of demand in LNG-for the inland waterway transport.

LNG is currently being used successfully as fuel on five Dutch inland waterway vessels.

LNG in the Heavy Good Transport

Outside Europe, many companies are already relying on gas as a fuel in Heavy Good Vehicle (HGV) transport. 15 million cars are already running on natural gas throughout the world; thousands of trucks run on LNG in China and the USA. For some years now in the Netherlands, trucks such as those operated by the food retailer Albert Heijn and Vos Logistics have also been running on LNG, bringing the total in the country to about 230.

In Germany the network of LNG service stations is growing equally.

As per April 2021 there are in service a59 LNG filling stations, furthermore 47 are planned to be built. (source: LNG-Taskforce). According to the German Energy Agency (dena) it is aimed to put in service about 200 LNG service stations in Germany to fuel up to 25,000 heavy good trucks.

Shell operates 12 LNG fuelling stations throughout Germany and plans to double its network of LNG fuel stations till the end of 2021 and to gradually switch all its sites to CO2-neutral bio-LNG.

Alternoil, the fuelling station operator from Steinfeld in the Lower Saxony, operates 16 LNG fuelling stations in its partner network as per April 2021. The company aims to put in service totally 35 LNG fuelling stations by the end of 2021. After 2021, Alternoil plans to build 28 additional LNG service stations.

Paneuropa, the nearby logistics company, plans to fully convert its fleet of vehicles to LNG latest by the end of 2021.

The Rostock based logistic company Spedition Heinz Gustke yet in June 2019 included 30 fuelled HGV into its fleet.

Reduction of greenhouse gas emissions