Hydrogen electrostatic sparks

The research into energetic molecules which produce a large amount of gas per unit mass, led to molecular structures which have a high hydrogen to carbon ratio. Examples of these structures are hydrazinium nitroformate (HNF) and ammonium dinitramide (ADN). The majority of the development of HNF has been carried out in The Netherlands whereas the development of ADN has taken place in Russia, USA and Sweden. ADN is a dense non chlorine containing powerful oxidiser and is an interesting candidate for replacing ammonium perchlorate as an oxidiser for composite propellants. ADN is less sensitive to impact than RDX and HMX, but more sensitive to friction and electrostatic spark. 

During the test, hydrogen flow rate was raised to a maximum of approximately 55 kg/s (120 Ib/s). About 23 seconds into the experiment, a reduction in flow rate began. Three seconds later, the hydrogen exploded. Electrostatic discharges and mechanical sparks were proposed as probable ignition sources. The explosion was preceded by a fire observed at the nozzle shortly after flow rate reduction began. The fire developed into a fireball of modest luminosity, and an explosion followed immediately. 

HAZARD RISK Flammable dangerous fire hazard explosion hazard with air mixtures of ether vapors can form peroxide that detonate when heated decomposes on heating and on contact with water, producing toxic and corrosive fumes of hydrogen chloride and formaldehyde may generate electrostatic charges can ignite by electric sparks attacks many metals, resins and plastics NFPA code not available... 

Molecule 5, C5H4 Removal of an appropriate pair of hydrogens from 3 gives, as an alternative to 4, molecule 5, tetracyclo[2.1.0.0 . 0 ]pentane, pyramidane. This was still unknown as of early 2007, despite having sparked a fair amount of interest (19 references in Chemical Abstracts) because it is the canonical molecule with a pyramidal carbon atom. Pyramidane was discussed in Chapter 2. Noteworthy are the facts that it has a lone pair at the apex (prominent electrostatic potential region), and that computations provide good evidence that it will prove to be reasonably stable, perhaps even isolable at room temperature. 

Ono, R., Nifuku, M., Fujiwara, S., Horiguchi, S., Oda, T., 2(X)7. Minimum ignition energy of hydrogen-air mixture effects of humidity and spark duration. Journal of Electrostatics 65 (2), 87-93. 

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