Fuel Cell is more prospective environmentally friendly and economically than electric or hybrid. Fuel Cell dominantly need hydrogen gas. That is why we should know more about hydrogen fuel.
Hydrogen fuel itself can be produced from hydrocarbons or water. By a generator or fuel cell, hydrogen gas is converted to produce electricity. Byproduct of this process is water. It is compared to electric or hybrid cars that fuel cell car is more attractive for development. He is free electricity from the battery power making it the cleanest cars on the road. Moreover, reaching distance of battery powered cars are still limited.
Hydrogen gas is highly reactive gas. Even at a concentration of 4-74%, hydrogen gas form explosive mixtures with air. The mixture will spontaneously explode because it is triggered by fire, heat or sunlight. For this reason, the use of hydrogen as a fuel should be very careful. Although the energy density per gram of hydrogen gas is greater than gasoline, but per volume of energy density is lower. Various storage technology of hydrogen gas has been developed by considering the cost, weight and volume, efficiency, durability, time charging and discharging (charge and discharge), working temperature and efficiency.
1. High-pressure tank
Technology is the most common and simple volumetric and grafimetrik albeit inefficiently.Higher the pressure, more energy per unit volume. An uncompressed hydrogen has the energy density of 10.7 kJ / L, when it is compressed at 750 bar pressure, energy density increases to 4.7 MJ / L. But there is still much smaller than gasoline, which it is 34.656 MJ / L
2. Liquid hydrogen tank (cryogenic)
In this technology, hydrogen gas is liquefied at very low temperatures. At a pressure of 1 atm, required temperature is to 22 K. It is enough energy to cool hydrogen energy up to one third of the stored energy. Energy density is up to 8.4 MJ / L. Although it is very heavy, but the volume is smaller than the high pressure tank making it suitable for static applications.
3. Metals and alloys
Metals or metal alloys (alloy)-like sponge can absorb hydrogen. Hydrogen will imbibition in interstitial spaces in the crystal lattice of metal so that hydrogen is not flammable and safer. For example: TiFe (1.5 wt%) and Mg2NiH4 (3.3 wt%).
4. Chemical
In this method, hydrogen is stored in the form of another chemical compound that is more secure. At the time of use, new compounds are converted into hydrogen through a chemical reaction.
a. Methanol
Infrastructure for distribution of methanol is very easy because it is as same as gasoline. When it is used, methanol is converted to H2 gas by releasing CO and CO2 gas.
b. Ammonia
Volumetric efficiency is slightly higher than methanol but it is toxic. it must be catalized at 800-900 oC for temperatures to release hydrogen. It is normally distributed in the form of liquid at a pressure of 8 atm.
c. Metal hydride
It is a reactive compound which it will soon release the hydrogen when reacting with water. Examples are the Well, LiH, NaAlH4, NaBH4, LiBH4, and CaH2
5. Fisisorpsi:
In this method, the hydrogen will be adsorbed on the surface of porous materials such as graphite nanofiber, carbon nanotubes, zeolites and Metal Organic Framework (M
