Mike wrote, > In short, liquid N2 ****is not a FUEL source****. At best it is an energy transfer medium, like a battery or compressed air.
Yes, but we can muddy the water somewhat by proposing a liquid air hybrid. Liquid air can be a fuel, of sorts. Fred - what do you think about this.... Nitrogen is roughly 80% of air and has little value as an oxidizer. Oxygen is a strong oxidizer. All strong oxidizers can technically be called fuels, especially if they can be enriched to the level of being able to superoxidize water. Moreover, in the process of liquefying air, it is just as efficient (almost) to both liquefy and enrich the end product in oxygen. LOX has drawbacks and is not really needed. By compressing air in two stages (which is normal) and separating the "first" stage of expansion magnetically (oxygen has good paramagnetism, nitrogen no) then you can chill the second stage with the nitrogen separated from stage-one and not loose any significant energy. IOW producing liquid enriched air of about 40% O2 content is almost as energy efficient as producing LN, and you do end up with a "fuel" of sorts, and it is one with extraordinary "lust" for "free"electrons and it can superoxidize (burn) water. It is dangerous and must be handled carefully. More on those details in a latter post on how to use this speculative process to perhaps quadruple the energy released per unit of cryo-liquid carried - compared to normal LN. However, one must realize that unless the electricity used to liquefy air or any gas mixture is coming from a nuclear plant (or wind, solar etc), there will still be carbon released "somewhere" to make any cryo-liquid. Nevertheless, this still could be beneficial as the Carnot numbers make it more appealing than many realize. Plus during the cryogenic stages, some CO2 can be removed but not nearly as much as is produced in a coal fired plant making the electricity. It still beats a gasoline engine in all respects. This ability to separate magnetically is due to differences in electron distribution, called the Lewis structure. O2 has an unpaired electron on each atom. Molecules with unpaired electrons are paramagnetic and exhibit magnetic properties. With oxygen the magnetic properties are pretty dramatic, as the following images show. The Lewis structure of N2 does not have unpaired electrons. Molecules with no unpaired electrons that do not exhibit magnetic properties and are diamagnetic and very easy to separate in the first stage of a two stage liquefaction process . http://www.chem.uiuc.edu/clcwebsite/liquido2.html Think about it. What would you rather have - a real liquid fuel or a real chill.... Jones
