Lightweight hydrogen storage for hydrogen vehicle

The one storage has been constructed for incorporation into a Ford Focus, which has been converted to hydrogen operation by NFVE. The storage fulfil the following specificatons: 1) Trunk dimensions: 104x75x55 cm. 2) Storage pressure: 1-200 bar. 3) Storage capacity (200 bar): 1,21 kg hydrogen approx 145 MJ (LHV) approx 4,5 L gasoline. 4) Discharge rate: 100 Nl/min at start, 500 Nl/min at accelration, 250 Nl/min at 80 km/h. IRD (DK) and CRF (I) have constructed the other two storages for incorporation into each a Fiat Sciento Elletra car converted to fuel cell operation. The storages fulfil the following specificatios: 1) Max dimensions: 110x90x60 cm. 2) Storage pressure: 1-200 bar. 3) Storage capacity (200 bar): 0,72 kg hydrogen approx 87 MJ (LHV) approx 2,7 L gasoline. 4) Discharge rate: 60 Nl/min. The present storages can easily be converted to operation at 300 bars. All components are specified for 300 bar operation except the pressure regulators. The possibility of making an all polymer fibre reinforced tank was investigated experimental. The hydrogen loss through different polymer liners in test tanks was measured. The losses ranged from nothign using a metallised polymer liner up to 2.6%/month for a pure polymer liner. There results indicate that it is possible to make sufficient hydrogen tight fibre reinforced tanks with polymer liners. Substitution of the present aluminium liner with a polymer liner will reduce the tank weight from 4.5 kg to approx. 2.4 kg