Gas as a transport fuel
Natural gas is a fundamental player in a low-carbon future: clean combustion, low carbon dioxide (CO2) emissions (even carbon-neutral when renewable gas applies), technology maturity, availability and competitive fuel cost are key factors to boost the role of natural gas. Through compressed natural gas (CNG) and liquefied natural gas (LNG), a complete range of applications can be supported, from small city cars up to long-haulage trucks, as well as in the maritime sector.
Benefits of gas in transport
Natural gas as a transport fuel offers important benefits to consumers, the environment and the economy. It provides a quick and cost-effective way to meet key EU objectives, including decarbonising road transport and improving air quality in cities.
Natural gas is an immediately available alternative to oil, with lower GHG emissions than any other hydrocarbon fuel and emitting virtually none of the pollutants (particulate matter and nitrogen oxides or NOx) that increasingly contaminate the air in areas with dense traffic. Vehicles fuelled by natural gas are quieter compared to Diesel and offer a lower total cost of ownership compared to conventional fuels. The technology used in natural gas vehicles is mature and safe.
Gas as a vehicle fuel is available as compressed natural gas (CNG) and liquefied natural gas (LNG). It can be used for cars, vans, buses and trucks, with many different models on the market today from established manufactures. LNG is also becoming the fuel of choice for the shipping industry due to its low sulphur emissions.
Natural gas also offers important synergies with biomethane from waste and biomass or synthetic gas produced using wind and solar energy. When using renewable gas, a quasi carbon-neutral mobility is achieved without any impact on the infrastructure and vehicle technology.
‘g-mobility’ stands for gas as a transport fuel that enables cleaner mobility, low-emissions transport and efficient use of gas in passenger cars, trucks, public transportation, and ships. It has vast potential to enable a cleaner future for transport, in which use of natural and renewable gas contribute to decarbonisation and improved air quality.
g-mobility is also an open energy platform where — thanks to the flexibility of natural gas technologies — bio and synthetic fuels can be easily integrated, creating a solid link to the renewable electricity sector and green hydrogen.
NGVA Europe’s flagship product – a map of CNG and LNG fuelling stations across Europe – provides real-time information on the development of natural gas fuelling stations in Europe. The map is continuously updated and improved to reflect the current situation on the number of CNG and LNG filling stations in operation or planned.
Which kind of CNG vehicles are available in EU?
Several car manufacturers in Europe are producing different CNG models, ranging from small city cars to luxury sedan for private use. For commercial use, small vans, buses, coaches and trucks that run on CNG are available. NGVA Europe tracks all models on an annual basis, with the latest information available here.
Which kind of LNG vehicles are available in EU?
Vehicles manufacturers in Europe are producing different LNG models, mainly trucks and buses. NGVA Europe tracks all models on an annual basis, with the latest information available here.
Where are the CNG stations in EU?
NGVA Europe provides locations and details for all CNG stations in Europe, including information on renewable natural gas content sold at operating or planned CNG stations. Our CNG station map can be found here.
Where are the LNG stations in EU?
NGVA Europe provides locations and details for all LNG stations in Europe, including filling procedure guidelines, contact information, planned stations, etc. Our LNG station map can be found here.
What is CNG?
CNG (compressed natural gas) is the most widely used technique to store natural gas in vehicles. Natural gas provides for CNG to be subsequently distributed to filling stations via the current gas network from where it can be easily compressed and transferred to natural gas vehicles and used as fuel. Natural gas is compressed up to 200 bars at the station and stored in high pressure storage system at filling stations where it will be used to fill NGVs through dedicated filling nozzles. A 100-litre gas tank at 200 bars contains approximately 16 kg of CNG, thta has the same energy content of 22-23 litres of diesel fuel.
CNG is commonly used by passenger cars, vans, buses and trucks, particularly in urban areas where distances between refuelling points are relatively short. Many city buses, for example, are fuelled by CNG: benefitting from close to zero pollutants of particulate matter and NOx, the use of CNG substantially reduces air pollution and contributes significantly to a healthier urban environment. CNG is increasingly offered as bio-CNG: adding varying percentages of biomethane to the gas mix increases the potential for CO2 reduction.
What is LNG?
LNG (liquefied natural gas) is natural gas converted to liquid by cooling it to -163 degrees Celsius. It is stored in insulated containers that keep the gas liquid. LNG achieves a higher reduction in volume than with CNG, meaning that a larger amount can be transported over a longer distance. Natural gas from the Middle East is carried as LNG in special ships to Europe and the United States, where LNG is gasified and injected into the natural gas grid or distributed by road.
LNG use in vehicles also offers the possibility to cover longer distances, making it an ideal fuel for trucks and buses. Compared to CNG the energy content of the unit of volume is three time higher: 1 liter Diesel fuel corresponds to 4,7 liter CNG at 200 bar and to 1,6 liter LNG.
NGVA Europe actively supports the creation of an extensive network of LNG filling stations for trucks in Europe. It works together with the NGV industry in the Blue Corridors project, which demonstrates that LNG can be a viable alternative to diesel in long-distance haulage. Due to its low sulphur emissions LNG is becoming the fuel of choice also for the shipping industry. LNG can also be produced from renewable sources, blended with natural gas and used as bio-LNG.
Filling a CNG vehicle
Two options are available for CNG filling; fast filling at public CNG filling stations or time filling for fleets or at home overnight. In both options, the CNG-connector is connected to the receptacle on the vehicle, triggering the start of an automated filling process in which gas is compressed and transferred from the source into the tank. After filling, pressure on the connector is released and safe disconnection is possible. The filling time for an average CNG vehicle is equivalent to a conventional fuel vehicle.
Filling an LNG vehicle
LNG vehicles are filled through standardized filling nozzles and receptacles. The standard filling procedure involves grounding the vehicle, followed by cleaning of the receptacle and nozzle with optional attaching of vent lines from the vehicle to the filling station. After connecting the nozzle to the LNG vehicle, the driver or operator presses the ‘dead-man’ switch to start the automatic filling procedure. Filling stops automatically when the vehicles is full. The receptacle and nozzle are released and cleaned. Filling times are equivalent to that of a diesel filling operation. Protective safety equipment needs to be worn during the entire filling procedure.
What is renewable gas?
Renewable gas is natural gas produced from any renewable source, and includes biomethane, synthetic gas, hydrogen. It can be produced through different pathways. For example, through anaerobic digestion (biological processes in which microorganisms break down biodegradable material) bio-waste is converted into biogas and upgraded to biomethane. Gasification is a process that converts organic waste with high carbon content into carbon monoxide, hydrogen and carbon dioxide, then combined to produce synthetic methane. Power-to-Gas is a process in which excess renewable electricity is converted to hydrogen and upgraded via methanation to methane. All renewable gas can be blended with natural gas and used as fuel for NGVs.
Bio-CNG compressed natural gas from renewable sources, e.g., from anaerobic digestion of organic waste sources
Bio-LNG liquefied natural gas from renewable sources, e.g., from anaerobic digestion of organic waste sources
Bio-SNG synthetic natural gas from renewable sources, e.g., from lignocellulose gasification
CH4 methane, a chemical compound, the main constituent of natural gas
CI compression ignited engine, ignition of the fuel through mechanical compression
CO2 carbon dioxide, a greenhouse gas
CNG compressed natural gas
DISI direct injection spark ignition, at high pressure fuel is injected in the combustion chamber and ignited through a spark plug
Euro 5,6 European Union emission standard for passenger vehicles
Euro V, VI European Union emission standard for heavy-duty vehicles
EU-28 European Union with its 28 Member States
FQD Fuel Qualitative Directive, regulation the sustainability of biofuels
GHG greenhouse gas, a gas that absorbs and emits radiation within the thermal infrared range
HDV heavy-duty vehicle, the category of vehicles including trucks, buses and coaches with weight over 3,5 tonnes or passenger vehicles with more than eight seats
HPDI high pressure direct injection, a process in which high pressure fuel is injected into the combustion chamber of an engine and ignited through a mechanical compression
JRC Joint Research Centre of the European Commission to support European policies with independent evidence
kWh kilowatt hour, unit of energy
LCA life-cycle assessment, a systematic set of procedures for compiling and examining the inputs and outputs of materials and energy and the associated environmental impacts directly attributable to the functioning of a product or service system throughout its life cycle
LDV light-duty vehicle, the category comprising passenger cars and vans with weight below 3,5 tonnes
LNG liquefied natural gas (stored @-163 degrees Celsius)
NEDC New European Driving Cycle, designed to assess the emission levels and fuel economy in passenger cars
NGV natural gas vehicle
Nm3 normal cubic metre, referenced at a temperature of 0°C and pressure of 1.01325 bar atmosphere
NOx nitrogen oxides, pollutants responsible for smog and acid rain
OEM original equipment manufacturer
PtG Power-to-Gas, process of creating synthetic natural gas from excess renewable electricity.
RDE real driving emissions, a test that measures pollutants and emissions emitted by vehicles while driving on the road
RED Renewable Energy Directive, policy for the production and promotion of energy from renewable sources in the EU
SI spark-ignited engine, a combustion process in which the air-fuel mixture is ignited by a spark from a spark plug in the combustion chamber
SNG synthetic natural gas, natural gas produced from synthesis of H2, CO or CO2
SOx sulphur oxides, pollutants responsible for respiratory symptoms and acid rain
TtW tank-to-wheel, part of the life-cycle assessment that considers only the vehicle energy use and emissions from tailpipe
WLTP Worldwide Harmonised Light Vehicles Test Procedure (for passenger vehicles and light commercial vans), a new regulatory test procedure for emissions and consumption for light duty vehicles following up NEDC from September 2017
WtT well-to-tank, part of the life-cycle assessment that considers only the impact from fuel production, transmission and distribution till the vehicle tank
WtW well-to-wheel, the combination of well-to-tank and tank-to-wheel analysis
WtX well-to-X (e.g., well-to-wheel, well-to-wake, and well-to-grid), part of the life-cycle assessment that considers different pathways for fuel production and energy uses, as well as associated emissions