Re Green Gas28 Oct 2018 16:09
Spud (or anyone else please)
I'm not trying to be deliberately negative here but there seems to be two MAJOR concerns with using hydrogen as a fuel.
1)Extreme explosive nature to the point of self igniting if freed from confinement.
2) Most Hydrogen comes from within natural gas or water, both processes to produce hydrogen gas expend more energy than is economical.
These two points are shown below.
https://www.resilience.org/stories/2006-01-03/myth-hydrogen-economy/
All free hydrogen generated today is derived from natural gas. So right off the bat we have not managed to escape our dependency on nonrenewable hydrocarbons. This feedstock is steam-treated to strip the hydrogen from the methane molecules. And the steam is produced by boiling water with natural gas. Overall, there is about a 60% energy loss in this process. And, as it is dependent on the availability of natural gas, the price of hydrogen generated in this method will always be a multiple of the price of natural gas.
Ah, but there is an inexhaustible supply of water from which we could derive our hydrogen. However, splitting hydrogen from water requires an even higher energy investment per unit of water (286kJ per mole). All processes of splitting water molecules, including foremost electrolysis and thermal decomposition, require major energy investments, rendering them unprofitable.
https://www.researchgate.net/publication/288039486_The_explosion_characteristics_of_methane_hydrogen_and_their_mixtures_A_computational_study
... In contrast to hydrocarbons, there are no established methods for the assessment of consequences arising from open air explosions in- volving hydrogen. The methods that are used for hydrocarbons, and which generally take partial confinement into consideration, may have limited applicability for hydrogen because, compared to hydrocarbons and several other flammable vapours/gases, hydrogen is much more reactive, has the broadest range of flammability limits (4%-75% v/v in air), requires low ignition energy, and has a negative Joule-Thompson coefficient (Gupta, 2008;Kang et al., 2015;Thomas et al., 2015;Faghih et al., 2016;Klebanoff et al., 2017). All these aspects imply that if leaked from its confinement, hydrogen may self-ignite. ...
Setting you a huge challenge...sorry in advance (I really want to be convinced).....but can you give a basic (trust me...it needs to be basic for me to understand!) rebut to these two problems.
Sorry again for the hassle.