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1.80 [16] 1.26: battery, Fluoride-ion [citation needed] 1.7: 2.8: battery, Hydrogen closed cycle H fuel cell [17] 1.62: Hydrazine decomposition (as monopropellant) 1.6: 1.6: Ammonium nitrate decomposition (as monopropellant) 1.4: 2.5: Thermal Energy Capacity of Molten Salt: 1 [citation needed] 98% [18] Molecular spring approximate [citation ...
Liquid hydrogen also has a much higher specific energy than gasoline, natural gas, or diesel. [12] The density of liquid hydrogen is only 70.85 kg/m 3 (at 20 K), a relative density of just 0.07. Although the specific energy is more than twice that of other fuels, this gives it a remarkably low volumetric energy density, many fold lower.
Hydrogen compressors are closely related to hydrogen pumps and gas compressors: both increase the pressure on a fluid and both can transport the fluid through a pipe.As gases are compressible, the compressor also reduces the volume of hydrogen gas, whereas the main result of a pump raising the pressure of a liquid is to allow the liquid hydrogen to be transported elsewhere.
The stone or stone weight (abbreviation: st.) [1] is an English and British imperial unit of mass equal to 14 avoirdupois pounds (6.35 kg). [ nb 1 ] The stone continues in customary use in the United Kingdom and Ireland for body weight .
The Space Shuttle main engine's turbopumps spun at over 30,000 rpm, delivering 150 lb (68 kg) of liquid hydrogen and 896 lb (406 kg) of liquid oxygen to the engine per second. [7] The Electron Rocket's Rutherford became the first engine to use an electrically-driven pump in flight in 2018.
For some usage examples, consider the conversion of 1 SCCM to kg/s of a gas of molecular weight , where is in kg/kmol. Furthermore, consider standard conditions of 101325 Pa and 273.15 K, and assume the gas is an ideal gas (i.e., Z n = 1 {\displaystyle Z_{n}=1} ).
At an electricity cost of $0.06/kWh, as set out in the Department of Energy hydrogen production targets for 2015, [73] the hydrogen cost is $3/kg. The US DOE target price for hydrogen in 2020 is $2.30/kg, requiring an electricity cost of $0.037/kWh, which is achievable given recent PPA tenders for wind and solar in many regions. [74]
The sequence of endothermal dehydrogenation followed by hydrogen purification is considered as the main drawback which limits the overall efficiency of the storage cycle. [1] LOHC shipping without heat recycling has an energy efficiency of 60-70%, depending on the dehydrogenation rate, which is equivalent to liquid hydrogen shipping.