Timeline for What are disadvantages of methane or ammonia compared to dihydrogen for metal ore reduction?
Current License: CC BY-SA 4.0
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Jul 21, 2023 at 7:50 | comment | added | Poutnik | Note that one of methods to produce hydrogen by easy means is letting water vapor to pass (red hot?) iron peelings. $\ce{3 Fe + 4 H2O -> Fe3O4 + 4 H2}$, resp. $\ce{ Fe + H2O -> FeO + H2}$. | |
Jul 20, 2023 at 21:36 | comment | added | Karl | At temperatures where H2 effectively reduces iron oxide, NH3 falls apart into its base components. Which means there is no point in making NH3 in the first place. | |
Jul 20, 2023 at 9:54 | comment | added | Poutnik | In a summary, you are correct. Additionally, NH3 and CH4 would still keep disadvantages of H2, regarding metallurgic aspects. For some other metals than iron, hydrogen is already used, especially if carbon is not applicable. | |
Jul 20, 2023 at 9:53 | comment | added | tobalt | Just to make sure I understand correctly: Does it mean that CH4 and NH3 aren't really reducing agents in molecular form, but only CO, C or H2 are? And that only the tiny amount of elemental H2 that thermally cracks from e.g. CH4 would work as an active reducing agent? | |
Jul 20, 2023 at 9:21 | comment | added | Poutnik | You are really mistaken. Review what the partial pressure is. Sure, C content is against the whole H2/CH4/NH3 agenda. All that would be energetically and technologically very challenging. I did say chemists would not use CH4 nor NH3 (but H2 or C or CO), as you have asked a "simple chemistry question". | |
Jul 20, 2023 at 9:14 | comment | added | tobalt | Why would they not use CH4 or NH3 is the main question. The partial pressure of "hydrogen" at the same gas pressure is higher in both CH4 and NH3 than in H2, having 4 and 3 hydrogen atoms per molecule, instead of 2 if I am not mistaken. And the production of CO2 from renewably generated CH4 is of course exactly a net zero. The C alloy content in these metals is not really an argument pro-hydrogen either is it ? In summary, I don't see how this answer adresses the question in its current state. | |
Jul 20, 2023 at 7:06 | history | answered | Poutnik | CC BY-SA 4.0 |