Total uses first featured compressed H2 and BMW CCH2 technology
Total has opened a hydrogen fuelling station in Munich which features the first public fuelling station where two pumps dispense hydrogen using two different types of refuelling technology. The first is a&nbsp;cryo-compressed hydrogen storage technology developed by BMW which involves&nbsp;storing gaseous hydrogen at low temperature on board the vehicle at a pressure. The second pump used an industry-standard 700 bar CGH2 hydrogen storage technology.
Cryo-compressed hydrogen storage, being developed by the BMW Group based on its long experience with cryogenic storage, involves storing gaseous hydrogen at low temperature on board the vehicle at a pressure of up to 350 bar. It is currently at the advanced development stage and will only come on stream for general use over the longer time frame. CCH 2 tanks offer up to 50% more hydrogen storage capacity than 700 bar tanks and can support a driving range of more than 500 kilometers (310 miles).

Total has opened a hydrogen filling station on Munich’s Detmoldstraße. The station, which completes the European HyFIVE project’s South Cluster—comprising Stuttgart, Munich, Innsbruck and Bolsano—is the first public filling station at which the two pumps dispense hydrogen using two different types of refueling technology: industry-standard 700 bar CGH 2 hydrogen storage technology ( SAE J2601 ); and cryo-compressed hydrogen storage technology (CCH 2 ).



From a 2010 paper by BMW and Lawrence Livermore researchers describing CCH 2 technology. Commercial automotive hydrogen storage technologies occupy the extremes of this phase diagram. Hydrogen is often stored as a compressed gas (red dot) at ambient temperature (horizontal axis), very high pressure (dotted lines), and relatively low density (vertical axis). Hydrogen is much more compact as a cryogenic liquid (blue dot) but with higher energetic cost (solid lines indicate the theoretical minimum work, also known as thermomechanical exergy) to compress and/or liquefy hydrogen.



Cryogenic-capable pressure vessels have flexibility to operate across a broad region (shaded in green) of the phase diagram, and therefore can be fueled with gaseous H 2 at a low energetic cost when energy or fuel cost savings is important or, respectively, with LH 2 or cryogenic hydrogen at elevated supercritical pressures when long driving range is desired.



Aceves et al. Click to enlarge.

BMW recently showcased two hydrogen fuel cell demonstrator models—BMW i8 and BMW 5 Series Gran Turismo. Half of the fuel cell 5 Series GT has 70MPa (700 bar) CGH2 storage and the other half has CryoCompressed at 35MPa (350 bar). The i8 Fuel Cell Vehicle only has 70MPa CGH2 Storage. (Earlier post.)

US DOE and CCH2 The DOE Hydrogen Program conducted a technical assessment of cryo-compressed hydrogen storage for vehicular applications during 2006-2008. The term “cryo-compressed” was coined by Salvador Aceves and colleagues at Lawrence Livermore National Laboratory (LLNL) and refers to their concept of storing hydrogen at cryogenic temperatures but within a pressure capable vessel, in contrast to liquid (or cryogenic) vessels which store hydrogen at low pressures. Cryo­-compressed hydrogen storage can include liquid hydrogen or cold compressed hydrogen. LLNL designed and fabricated a cryogenic-capable insulated pressure vessel (up to 350 bar) for on-board hydrogen storage applications. BMW worked with LLNL in the development of a prrof-of-concept and in the review of the technology.

In order to research and develop both types of tank system and their integration in the vehicle, BMW Group needs to have both systems available for testing in the real world and not just in the laboratory. Much more realistic test scenarios can be achieved if lab tests are supplemented by testing at a public filling station, the company said.

BMW says that since fuel cell electric vehicles are particularly suited to longer-distance trips, they are an ideal complement to the BMW i models, and to the future plug-in hybrid production models from the BMW brand, which will be based on the already proven eDrive technology. In the long run, the company said, hydrogen fuel cell drive will become an integral part of BMW’s Efficient Dynamics program, adding to the diversity of the BMW Group’s powertrain portfolio. This portfolio can be flexibly tailored to different vehicle concepts, customer requirements and legal and regulatory requirements in the international automobile markets.

However, a basic requirement for the successful introduction of hydrogen fuel cell vehicles is the development of a hydrogen refuelling infrastructure in the relevant automobile markets. In important initial markets for hydrogen, such as Japan, California/USA and Europe (particularly Germany, the United Kingdom and Scandinavia), it is realistic to assume that the current infrastructure initiatives will lead to the establishment of an initial hydrogen refueling infrastructure by around 2020. Unlike Japan, which as an island has little or no need to make allowances for cross-border traffic, Europe faces much more challenging requirements in terms of ensuring a transnational infrastructure.

The BMW Group is therefore actively contributing its expertise as a partner in important initiatives for the development and planning of a hydrogen infrastructure, such as the H2 Mobility and CEP initiatives in Germany, and also as an active member in the EU’s Fuel Cell Hydrogen Joint Undertaking. The BMW Group is also collaborating intensively with Total Germany and the Linde Group on refueling processes and technology.

Over the long term, moves are afoot to use power-to-gas electrolysis to store surplus renewable electricity in the form of hydrogen. Production of hydrogen from surplus electricity would offer a realistic long-term prospect of ensuring a cost-efficient supply of green hydrogen for use in fuel cell electric vehicles.

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