In Munich on the street Detmoldshtrasse yesterday, July 16, was put into operation the world’s first public hydrogen station that combines two technologies gas stations, one of which is fundamentally new. The first – a fairly common industry standard CGH2 (sompressed gaseous hydrogen), hydrogen gas at a pressure of 700 atmospheres (bar). Second – CCH2 (cryo-compressed hydrogen), a technology patented by the group BMW. This method of storing hydrogen at cryogenic temperatures, but still in a gaseous form, not liquid, and a pressure of 350 atmospheres.
The project involved industrial partners and the government. From left to right: Andreas Opfermann (Linde Group), Guillaume Larroque (TOTAL), Matthias Klitts, White Shtaynle (German Federal Ministry of Transport and digital infrastructure).
When technology CCH2 cylinders contain 50% higher energy content than a pressure of 700 bar and at ambient temperature. This method can easily provide hydrogen passenger cars run over 500 km on one filling. However, the Germans point out that the massive use of standard CCH2 find not soon. But BMW intends to explore this method of refueling and storage of real, not the laboratory (the first vehicles to him, the Bavarians have already built). And yet this gas station has completed the creation of the so-called southern cluster (Stuttgart, Munich, Innsbruck and Bolzano) in the framework of a large European project HyFIVE Development hydrogen infrastructure. Now these machines can easily drive from southern Germany to northern Italy.
Until now, cars that run on hydrogen (as fuel elements and equipped with internal combustion engines that consume hydrogen) used several storage options H2. It cylinders with gaseous hydrogen compressed at a pressure of 350 atmospheres (examples – Honda FCX Clarity, Mazda RX-8 Hydrogen RE) or 700 atmospheres (as in the Hyundai ix35 / Tucson Fuel Cell).
The Mazda RX-8 hydrogen burned in the Wankel engine. The Honda FCX Clarity worked electrochemical generator, similar to the fuel cell installed in the interior of the crossover Hyundai.
According to the latest mass-produced cars (Toyota Mirai) and concepts (Audi A7 Sportback h-tron quattro, Honda FCV ), a combination of “fuel elements and cylinders at 700 bar” would be the most common variant of hydrogen technology in the coming years.
Regarding the mass model Mirai uses already common in Japan, the US and Europe standard filling . But in the experimental hatchback BMW 5 Gran Turismo provides both cylinders under the “700-aspirated» CGH2, and a chilled gas CCH2.
engineers applied tried and liquid hydrogen (BMW Hydrogen 7), which was kept in a well-insulated cryogenic tank at relatively low pressure, but at a temperature of? 253 ° C. This sedan burned hydrogen in the 12-cylinder engine.
The liquid hydrogen allows to store 75% more energy per liter in the calculation of volume than gas at a pressure of 700 bar. However, there is a lack of technology. No insulation could not stop even if slow, but still the heating tank. Hydrogen began to slowly evaporate. When pressure in the tank at six atmospheres of hydrogen “Seven» BMW opened a safety valve. Because of this, in the car, delivered to the parking lot, the entire stock of hydrogen disappeared within 12 days of inactivity. Most likely, this method of storing hydrogen on board the cars are never developed.