The H2 Project - A little bit about hydrogen

A little bit about hydrogen

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There are no warranty, express or implied, and legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights, in this document.The data in this document should only be seen as overall guidelines.

Basics

Hydrogen was discovered in 1766 by the English chemist and physicist H. Cavendish.

Hydrogen is the first element in the periodic table, consisting of one proton and one electron making it the smallest and lightest of all elements.

Hydrogen reacts with many different materials and is one of the most abundant elements in the universe, 90% of the atoms in the known universe are hydrogen. Hydrogen therefore can be produced from a various types of sources. The most important source is water, which can be split into hydrogen and oxygen by electrolysis.

Safety

Hydrogen is as dangerous as gasoline, but perhaps safer because of its safety characteristics.

• Hydrogen is lighter than all other elements.
• Hydrogen has a low density and thus a higher buoyancy
• Hydrogen diffuses faster through air than other gas fuels
• Hydrogen is odorless, tasteless, colorless and non toxically
• Hydrogen ignition interval covers large differences in concentration
• Hydrogen burning flame is invisible in day light
• Hydrogen ignition energy at certain concentrations are very low
• Hydrogen flame rate are quite higher than that of other fuels
• Hydrogen ignition temperature are quite higher than gasoline
• Hydrogen is explosive in a large concentration interval when concealed, but in open air difficult to explode

Hydrogen vs. Gasoline Safety properties

Characteristic	Hydrogen	Fuel
Ignition energy (MJ)	0,02	0,24
Ignition temperature (°C)	520	240
Ignition interval (concentration in air Vol. %)	4,1-72,5	1-7,6
Lower detonation level (concentration in air Vol. %)	13-18	1,1
Flame rate (m/sec.)	2.7	0.3
Flame radiation (%)	17-25	34-43
Buoyancy (relative density)	0,07	4
Diffusion (cm2/sec.)	0.61	0.05

Credits: www.miniHydrogen.dk

How to convert a car?

Hydrogen conversions are like natural gas (CNG) conversions. Many of the components may be rated for either fuel selection.

However, there are essential differences and opportunities gained by using hydrogen. Correctly engineered, a hydrogen engine can produce more power than similar displacement gasoline engine. A hydrogen engine is even less polluting than a natural gas vehicle, which is already lower compared with a gasoline or diesel engine. There are many considerations in doing a conversion to hydrogen; choosing a fuel delivery system (direct injection is best), selection of tanks, and placement of safety devices.

Production

Electrolysis can electrochemically split water into hydrogen and oxygen in essentially the reverse of the reaction in a fuel cell. To make sense for large-scale use, this process must use an inexpensive source of electricity. Because wind energy is currently the lowest cost renewable energy, it is the leading candidate. It is also an intermittent source that would benefit from being able to produce hydrogen when its electricity is not needed and to add fuel-cell generation when electricity demand exceeds what the wind turbines can provide. The combination also benefits because electrolyzers require direct current and wind turbine power must be converted to direct current before conversion back to alternating current suitable for the electric grid.

Credits: www.nrel.gov

Mema is back to Buenos Aires

After 2 months of hard work and adventurous travels, Mema has gone back to Buenos Aires. Thanks a lot for her support. We'll see again very shortly ;-)