Abuse of language wants called hydrogen engine engines based on a Fuel Cell. But some details are necessary:
1) The classic combustion engine (spark ignition) is able to burn pure hydogène some modifications for improved efficiency and reliability (the chamber materials, seats and valves, piston, ignition adaptation, etc. ...). The main difficulty resides in the storage Hydrogen (Gas 27 times lighter than air and so small that it diffuses into most materials)This type of engine could obviously be called Hydrogen Engine.
2) The "hydrogen" engines that the media are talking about are actually based on a fuel cell (see the specific pages on this technology for more information) that will "transform" hydrogen (and oxygen from air) in electricity and water (liquid or vapor).
So there is that liquid water and steam coming out of the exhaust.
The still big confusion possible with the "water engine" (That does not officially exist) because it is not because we reject water that is what we consume. Is what a gasoline engine is called motor CO2? Not of course!
3) Hydrogen is not an energy carrier in any case a power source (assuming we are not talking recess thermonuclear fusion). For as there is no (or very few) present on earth in the single state, we must transform it from other chemical elements, packaged, transported and stored. All these steps consume energy it takes obviously take into account the performance and emission technology or another. This is exactly what an MIT team.
The results are unfortunately (for his defenders ...) not for the fuel cell.
This excerpt from a Science & Avenir is from a study done by MIT and compares, in 2020, different propulsion technologies:
- Gasoline Hybrid
- Diesel Hybrid
- Hydrogen with fixed reformer
- Hydrogen with board reformer
The author presents the environmental impact for each technology: energy consumption at kilometer traveled (in MJ / km) and emissions of CO2 (in grams carbon / km).
He concludes that environmentally, the diesel hybrid can strongly concurencer car fuel cell (more econological in all cases with a PAC board reformer). Economically there is a good chance that the diesel hybrid is less chèr the CAP vehicles (especially with board reformer). The diesel hybrid is the most econological currently available vehicle.
Especially as the cost and the technological development of diesel hybrid is already developed, which is far from the case of PAC! These are just a macroeconomic concepts that hold back its market launch.
The results :
Click on the image to enlarge.
This page is an extract of Science & Avenir 676 2003 June. The official website
The 7 modes of hydrogen production.
Here are 7 possible means of production of hydrogen energy:
- Reforming of heavy hydrocarbons to steam
- Reforming of light hydrocarbons
- Biomass gasification
- Gasification of coal with water
- electrolysis nuclear
- renewable electrolysis