With the future fuel for the automotive industry looking likely to be hydrogen – one company has aimed to resolve a problem before the gas makes it to pump and public use.
Netherlands headquartered Teesing has spent years looking for a solution to the problem of expansion when hydrogen is being dispensed at the pump to the customer.
In the future, real integration and acceptance of hydrogen vehicles in our society will depend partly on the critical issue of ease of use for the public and familiarity with this ‘new’ type of energy. As human beings we are more quickly inclined to switch if things become cheaper, faster, more efficient, safer or more sustainable. Teesing recently finished the PusH project, in which it successfully filled cylinders fast and efficiently with hydrogen at 700 bar.
Why 700 bar?
Hydrogen has a lower energy content than natural gas, which means that the same volume contains less energy. To be precise, three times less than natural gas. Refuelling hydrogen at a higher pressure (so 700 bar) supplies enough energy to give a hydrogen car a respectable range. The hydrogen cylinder will have to be filled at 700 bar within three minutes, because most consumers will not wait longer than that at the filling station.
Problems at 700 bar
But the crux of the problem with filling hydrogen gas at high speed is that hydrogen gas expands when it becomes hot. Currently the solution for this problem is to pre-cool the hydrogen gas, but this inefficient method results in unnecessary loss of energy.
Solution for 700 bar
Teesing has developed a system which counteracts the expansion. The cylinder is first filled with water at a pressure of 700 bar, after which the water is displaced by introducing hydrogen gas into the cylinder at 700 bar. The prototypes have been tested successfully and a patent has already been issued for the PusH principle.
A company spokesman said, “No expansion, no heating, less energy loss and still possible to fill up FCVs quickly up to 700 bar. This method has the additional advantage that no extra action is required to moisten the hydrogen: fuel cells function more efficiently if the hydrogen has been moistened.”
“Teesing wants to follow up the commercial feasibility of this system. The company is considering a demonstration project by means of a subsidy or investment, in which the Tongji University can continue its involvement.”
The following partners were involved in the completed project:
- Tongji University Shanghai, China
- WEH, Hydrogen refuelling components, Germany
- Itensify, High pressure & Flow control systems, Netherlands