General formula for calculating the efficiency of hydrogen production by water electrolysis
1 cubic meter of hydrogen has a mass of 89.9 g and a heat quantity of 14 .3 x 10,000 x 89.9 = 12,855.7 kJ. Hydrogen production by electrolysis is generally around 55%. To produce 1 cubic meter of hydrogen, 12,855.7 kJ/55% = 23,374 kJ of electrical energy is required. The time required for electrolysis with a power of 100 W is: 23,374 kJ/0.1 = 233,740 s = 65 h (hours). )
Detailed information:
Production of hydrogen by electrolysis of water is a relatively convenient method of producing hydrogen. Direct current passes through an electrolytic tank filled with electrolyte and the water molecules undergo an electrochemical reaction on the electrodes and decompose into hydrogen and oxygen.
The principle of a hydrogen fuel cell is that the reverse reaction of water electrolysis provides hydrogen and oxygen at the anode and cathode respectively. Once the hydrogen has diffused outward through the anode and reacted with the electrolyte, it is released. electrons and reaches the cathode via an external charge. A hydrogen fuel cell refers to a device that reacts between hydrogen and oxygen to produce electrical energy (there are also "hydrogen internal combustion engines" driven solely by the combustion of hydrogen, like BMW's hydrogen 7 series). The driving force of a hydrogen fuel cell vehicle comes from the vehicle's engine, just like a pure electric vehicle, so a hydrogen fuel cell vehicle can be understood as an "electric vehicle with its own hydrogen generator" . Advantages of hydrogen fuel cells: No pollution: Hydrogen fuel cells do not pollute the environment. By electrochemical reactions rather than combustion(petrol, diesel) or energy storage (batteries). Burning releases pollutants such as carbon monoxide and dust. Fuel cells only produce water and heat. Noisy: Hydrogen fuel cells operate quietly, with only about 55 dB of noise, which is equivalent to the level of normal human conversation. This makes the fuel cell suitable for indoor installations or outdoor locations where noise is limited. High efficiency: The power generation efficiency of hydrogen fuel cells can reach more than 50%, which is determined by the conversion properties of fuel cells. It directly converts chemical energy into electrical energy without the need for intermediate conversion of thermal energy and mechanical energy (generator).