1 Introduction
Since the early 1970s the need for a clean and environmental friendly alternative to the use of fossil fuel in combustion engines, especially in individual transportation, has grown with ups and downs over time. Increased awareness of climate change and global warming have enforced the so called hydrogen energy transition, which describes the significant change from the dominant oil based technologies towards the use of hydrogen as a clean fuel in transportation. Although hydrogen could be used instead of fossil fuel in combustion engines, its replacement by a fuel cell is intended. It has a higher efficiency than a combustion engine, provides electrical energy to power an electrical drive, generates water as a by-product and …show more content…
Additionally, a compact and lightweight geometry and the ability to a quick refill play a major role as well. To generate a benchmark for hydrogen storage materials, the US Department of Energy (DOE) developed a catalogue of criteria, that had to be fulfilled to make the material interesting for the automotive industry. Table 1 presents the benchmarks for the single …show more content…
Unfortunately, 1 kg of hydrogen requires 11 m3 of volume at ambient temperature and pressure. In addition, a load between 4 and 8 kg is required to guarantee comparable driving ranges with petrol fuelled cars. It is obvious that ways have to be found to increase hydrogen density to a level where storage mobility is feasible. The following chapter gives a brief but uncomplete overview on possible ways of fulfilling this task and Table 2 shows a comparability of the different types in numbers. [2]
The most common storage system for gaseous hydrogen are high pressure gas cylinders, which can handle pressures up to 70 MPa. Size and wall thickness depend on the material used. Ideally these materials have a high yield strength, low density and guarantee no to little reactivity or diffusivity. Most common used are stainless steel, aluminium or copper. Now developments focus on high strength composite cylinders which can handle up to 80 MPa and increase the volumetric hydrogen capacity from 30 to 36 kg/m3. Thus compression of hydrogen could be easily done by using a simple piston-type compressor, safety concerns about the high pressure cylinders and relatively low hydrogen density make this method not an ideal solution.
Since the early 1970s the need for a clean and environmental friendly alternative to the use of fossil fuel in combustion engines, especially in individual transportation, has grown with ups and downs over time. Increased awareness of climate change and global warming have enforced the so called hydrogen energy transition, which describes the significant change from the dominant oil based technologies towards the use of hydrogen as a clean fuel in transportation. Although hydrogen could be used instead of fossil fuel in combustion engines, its replacement by a fuel cell is intended. It has a higher efficiency than a combustion engine, provides electrical energy to power an electrical drive, generates water as a by-product and …show more content…
Additionally, a compact and lightweight geometry and the ability to a quick refill play a major role as well. To generate a benchmark for hydrogen storage materials, the US Department of Energy (DOE) developed a catalogue of criteria, that had to be fulfilled to make the material interesting for the automotive industry. Table 1 presents the benchmarks for the single …show more content…
Unfortunately, 1 kg of hydrogen requires 11 m3 of volume at ambient temperature and pressure. In addition, a load between 4 and 8 kg is required to guarantee comparable driving ranges with petrol fuelled cars. It is obvious that ways have to be found to increase hydrogen density to a level where storage mobility is feasible. The following chapter gives a brief but uncomplete overview on possible ways of fulfilling this task and Table 2 shows a comparability of the different types in numbers. [2]
The most common storage system for gaseous hydrogen are high pressure gas cylinders, which can handle pressures up to 70 MPa. Size and wall thickness depend on the material used. Ideally these materials have a high yield strength, low density and guarantee no to little reactivity or diffusivity. Most common used are stainless steel, aluminium or copper. Now developments focus on high strength composite cylinders which can handle up to 80 MPa and increase the volumetric hydrogen capacity from 30 to 36 kg/m3. Thus compression of hydrogen could be easily done by using a simple piston-type compressor, safety concerns about the high pressure cylinders and relatively low hydrogen density make this method not an ideal solution.