Innovative compression solutions for efficient hydrogen mobility
Cosmhyc:
Learn more about
H2 production and benefits

Hydrogen is the simplest and most abundant element in the universe, but its gaseous form H2 doesn't occur naturally. H2 can be produced through different processes: reforming of natural gas, gasification of heavy fossil fuels, or water electrolysis. All are mature technologies applied on a large scale, mostly in industrial applications.

Electrolysis, a process of splitting water into hydrogen and oxygen by applying a direct current, can produce hydrogen directly from renewable electricity, providing a way to store it in chemical form.

The need for energy storage is becoming more acute with the increase of intermittent renewable electricity generation from wind and solar, which is not aligned with grid power demand. Water electrolysis technology is currently the most flexible solution for storing renewable electricity on a large scale in the form of H2.

When produced by electrolysis with electricity from renewable sources:

  • H2 allows storing low-carbon energy
  • H2 facilitates the integration of high shares of intermittently generated renewable electricity in energy systems
  • H2 is an option for increasing the flexibility of the energy system
Electrolyser by Nel Hydrogen © Nel Hydrogen 2017
Electrolyser by Nel Hydrogen © Nel Hydrogen 2017
H2 molecule
H2 molecule
COSMHYC:
Learn more about
fuel cell electric vehicles

In a fuel cell a hydrogen-rich fuel is oxidized and converted into heat and electricity. If pure hydrogen is used, the exhaust of fuel cells is only water vapour.

Fuel cell can be used for road passenger vehicles but also for industrial fleets and material handling vehicles, rail and air transport as well as for shipping, river navigation and pleasure boating. In Fuel Cell Electric Vehicles (FCEVs) powered by H2, the electricity needed for the engine is produced without any local pollutants emissions, eliminating local environmental and health impacts otherwise caused by transport. When H2 produced from renewables is used, overall CO2 emissions are significantly reduced and FCEVs are a low-carbon alternative to conventional transport.

The transport sector needs carbon-free solutions. A range of technical options are currently under development or are being introduced to the market: battery electric vehicles, plug-in hybrid vehicle, FCEVs or even industrial and commercial vehicles using liquid or gaseous hydrocarbon fuels synthesized from renewable hydrogen. A combination of these options is required to meet the different mobility needs of society and individuals. H2 mobility, alongside with battery technology, is thus part of the solution to fight climate change.

Cosmhyc:
Learn more about
Infrastructure for H2 Mobility

The on-road practicability of FCEVs has been demonstrated; moreover hydrogen cars are silent and comfortable. By the end of 2016 about 5,000 FCEVs were on the roads all over the world. At present, manufacturers start the production of affordable FCEVs in series. Well-developed infrastructures and efficient technologies for hydrogen refuelling stations are key to FCEVs market deployment.

The transport and distribution infrastructure can be composed of different elements depending on where the hydrogen is produced:

  • On-site production (or near the refuelling station): the electrolyser has to be installed and access to a sufficient amount of renewable electricity has to be ensured.
  • Off-site production: hydrogen needs to be compressed, pumped into the storage vessels (compressed hydrogen tube trailers or liquid hydrogen trailers for example) and transported (pipelines or trucks).
  • Storage solutions to ensure the availablitity of hydrogen.
  • Compressors are needed to supply high-pressure hydrogen to the FCEVs´ tanks.
  • Refuelling station for the distribution and the sale of the hydrogen fuel.
Hydrogen refuelling station in Hamburg © LBST 2017
Hydrogen refuelling station in Hamburg © LBST 2017
Cosmhyc:
Learn more about
hydrogen refuelling stations

With the market entry of FCEVs, the first hydrogen refuelling stations are currently opening in the EU. FCEVs can be refuelled in 3 to 5 minutes, thereby offering refuelling times similar to those of conventional cars. The stations can be exclusively for hydrogen or part of multi-fuel stations, located along roads.

FCEVs’ drivers should be able to refuel their vehicles when and wherever they need to. A hydrogen refuelling station network that lives up to this promise still has to be built-up in Europe. A minimum coverage through the territory is a prerequisite for increased usage of hydrogen vehicles. Refuelling stations should be located at the right places! Clustering them around demand centres and connecting corridors is an option to provide coverage at minimal costs and with maximum effect.

The optimal size of a station is another critical element and is largely determined by daily hydrogen demand. New generation fuelling devices are now entering the market, enabling hydrogen supply even at rush-hours. These devices are compact, saving space within the station and the storage capacity can be dimensioned to address different demand and supply configurations.

Refuelling station by Nel Hydrogen © Nel Hydrogen 2017
Refuelling station by Nel Hydrogen © Nel Hydrogen 2017
Cosmhyc:
Learn more about
H2 compression

Hydrogen is usually produced at low pressure (10 to 50 bar), but then must be compressed before transportation or distribution (350 to 700 bar for FCEVs). There are different technologies to compress hydrogen, most of them involving mechanical compression.

Below are some of the different types of compressors:

  • Reciprocating compressors use an engine to move back and forth a piston or a diaphragm. This method is widely used. By moving this piston, hydrogen is confined into a smaller volume and therefore mechanically compressed.
  • Rotary compression uses the rotation of screws, gears, etc. to force more gas into a given volume.
  • Centrifugal compressors are equipped with a turbine that rotates at a very high speed to compress H2

Alternatives technologies are also available to limit the electrical consumption and the noise and heat production, while reducing CAPEX and OPEX costs.

One of the most promising ones is the use of metal hydrides. Hydrogen is absorbed into a metallic powder at a certain pressure and can be released at a higher pressure thanks to an increase of temperature.

Pressure gauge © Nel Hydrogen 2017
Pressure gauge © Nel Hydrogen 2017
COSMHYC:
Learn more about
the economic impact of
hydrogen compression
on hydrogen fuel costs

To assure that hydrogen is an attractive fuel also from an economic point of view, hydrogen prices at the pumps need to be in the range of 8 to 10 € per kg of hydrogen. This translates roughly into fuel costs lower than 8 and 10 € per 100km.

Today, the costs for providing hydrogen to the vehicle user are often above this target value. In recent years innovations and technology development have already achieved significant cost reductions. However, further cost reductions e.g. by applying new and innovative compressor technologies are required. Currently, hydrogen compression at the refuelling station contributes between 1.5 and 2.5 € per kilogram to the total fuel costs. This shows the relevance for further innovation and development.

Fuel costs graph by LBST © LBST 2017
Fuel costs graph by LBST © LBST 2017