BAM and Germanischer Lloyd present tank concept
Report about a large-scale experiment
The Federal Institute for Materials Research and Testing (BAM), Berlin, and Germanischer Lloyd (GL), Hamburg as project coordinator in the Euro-Canadian joint project EQHHPP ("Euro-Québec Hydro-Hydrogen Pilot Project") made joint experiments on the safe transport of large amounts of cryogenic hydrogen.
Review of the press conference:
The project is funded by the European Commission, the industrial participants, and the Canadian partners. Main subject is technical safety in transport of cryogenic liquid hydrogen. The project deals with hydrogen which is generated by electrolysis of water (splitting of water in its elements hydrogen and oxygen). The electricity is from the surplus of Canadian hydropower stations. Transporting hydrogen in its liquid state requires less space than for gaseous hydrogen. The behavior of liquid hydrogen is still widely unknown. This is why the model tank with a geometric volume of 61 cubic meters was designed and manufactured by the project partners. It was transported to Horstwalde in June 1996 and filled with liquid hydrogen in August. The actual transport tanks for sea-going vessels will later have a volume of 3.600 cubic meters with a transport capacity of 3000 cubic meters liquid hydrogen.
Caption proposal:
Release experiment at a model tank for liquid hydrogen on the BAM test ground at Horstwalde. The white fogs consist of air moisture condensed by very cold hydrogen gas (above the tank) and liquefied air (on ground) occurring as a by-product.
Photo: BAM, Gollner
In the experiment of 13. September 1996 the hydrogen gas cushion which had been created above the liquid hydrogen in the tank was released. This process is comparable to the venting of an express cooking pot. The venting of the gas lets the pressure drop, more hydrogen evaporates, and the remaining liquid is further cooled. This process is monitored by means of temperature sensors in the hydrogen tank to gain data on the temperature stratification and other aspects of the thermal behavior. Further measurements cover the strains and other mechanical properties. The experiments are not yet finished, so that no final statements can be made now.
The release experiments aims as simulating the later emptying of the tank after transport. The tank designers want to keep the hydrogen losses in transport as low as possible. The thermal insulation shall be so good that over a transport time of e. g. 25 days the pressure rise is so low that the safety valves do not react. The resulting gas cushion above the liquid hydrogen provides a working pressure for driving the liquid out during off-take. So the use of special pumps for the transfer of cryogenic liquids is not necessary.
Dr. Gerd-Michael Wuersig (responsible for this project at Germanischer Lloyd Hamburg) illustrated the present state of thermal insulation by comparison with a common insulating coffee pot. It the latter's insulation would be as good as that of the model tank for liquid hydrogen hot coffee would only become seven degrees colder during one week.
Abraham Bahbout from the Joint Research Centre of the European Commission at Ispra (Italy) mentioned in his speech that the European Commission considers hydrogen as an important if not the only serious alternative to conventional fuels. Looking back on about 10 years of project work he said that good project work had been done.
GL board member Professor Dr. Eike Lehmann explained the significance which this project has for GL and gave a survey of the contributions of the other partners to the project. Horst-Dieter Buss (Thyssen Nordseewerke Emden), Jean-Michel Camus (Air Liquide, F-Sassenage), Michael Hoffmann (State Materials Test Institute, University of Stuttgart) and Dr. Ulrich Schmidtchen (Federal Institute for Materials Research and Testing, Berlin) gave further information about the project in short statements.
Your contact:
Dr. Ulrich Schmidtchen (BAM Berlin, phone: (+49-30) 8104-4402) or
Dr. Gerd-Michael Wuersig (Germanischer Lloyd Hamburg, phone: (+49-40) 36149-621
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