Haber process: Difference between revisions
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* Scaling: 100-200cc of gas per minute over 1kg of catalyst | * Scaling: 100-200cc of gas per minute over 1kg of catalyst | ||
See "The Direct Synthesis of Ammonia"<ref>{{cite pub|publication=J. Chem. Educ.|title=The Direct Synthesis of Ammonia: A lecture table experiment|first1=Alfred T.|last1=Lars|url=http://pubs.acs.org/doi/pdf/10.1021/ed002p285|year=1925}}</ref> for a description of producing the catalyst. | See "The Direct Synthesis of Ammonia"<ref>{{cite pub|publication=J. Chem. Educ.|title=The Direct Synthesis of Ammonia: A lecture table experiment|first1=Alfred T.|last1=Lars|url=http://pubs.acs.org/doi/pdf/10.1021/ed002p285|year=1925}}</ref> for a description of producing the catalyst. | ||
====Tungsten==== | |||
Apparently Tungsten can also be used as a catalyst at about 600°C and atmospheric pressure.<ref>{{cite pub | |||
|title=Lecture experiment on the synthesis and combustion of ammonia | |||
|first1= F.|last1=Fromm | |||
|pages=230 | |||
|journal=Journal of Chemical Education | |||
|year=1942 | |||
|volume=19 | |||
|issue=5 | |||
|doi=https://doi.org/10.1021/ed019p230 | |||
|url=https://pubs.acs.org/doi/abs/10.1021/ed019p230 | |||
}}</ref> | |||
====platinum==== | ====platinum==== | ||
===High Pressure=== | ===High Pressure=== | ||
| Line 21: | Line 32: | ||
The gasses are refrigerated, the ammonia removed as a liquid, and the process is repeated. Iron oxide can be used in place of iron, because it will be rapidly reduced by the hydrogen gas to water and pure iron. | The gasses are refrigerated, the ammonia removed as a liquid, and the process is repeated. Iron oxide can be used in place of iron, because it will be rapidly reduced by the hydrogen gas to water and pure iron. | ||
==Hazards== | ==Hazards== | ||
* At the extremely high temperatures and pressures involved, rupture and explosion of the reaction vessel is a serious concern. | * At the extremely high temperatures and pressures involved, rupture and explosion of the reaction vessel is a serious concern. | ||
Revision as of 01:06, 1 May 2020
The Haber Process is a vital industrial process which produces "fixed" nitrogen from atmospheric nitrogen, allowing the production of fertilizers and other nitrogen-based compounds. Hydrogen and nitrogen are run over a heated catalyst at pressure and bond to produce ammonia.
Process
Atmospheric pressure
plain iron oxide
Simple iron oxide can be used as a catalyst.
- The catalyst is purified Fe3O4 (magnetite) with the oxygen removed by exposure to hydrogen at high temperatures. This provides the appropriate porosity.
- The reaction takes place at 440-450°C and atmospheric pressure
- Yield is 0.25% ammonia
- Scaling: 100-200cc of gas per minute over 1kg of catalyst
See "The Direct Synthesis of Ammonia"[1] for a description of producing the catalyst.
Tungsten
Apparently Tungsten can also be used as a catalyst at about 600°C and atmospheric pressure.[2]
platinum
High Pressure
platinum
- Yield: 4-5%
promoted iron
- The catalyst is doped purified iron Fe + CaO + K2O + SiO2 + Al3O4
- The reaction takes place at 300–550 °C and 50–250 atmospheres.
- Yield is over 90%
The gasses are refrigerated, the ammonia removed as a liquid, and the process is repeated. Iron oxide can be used in place of iron, because it will be rapidly reduced by the hydrogen gas to water and pure iron.
Hazards
- At the extremely high temperatures and pressures involved, rupture and explosion of the reaction vessel is a serious concern.
See Also
References
- ↑ Lars, Alfred T. (1925) "The Direct Synthesis of Ammonia: A lecture table experiment"
J. Chem. Educ. - ↑ Fromm, F. (1942) "Lecture experiment on the synthesis and combustion of ammonia"; pp230.
DOI:https://doi.org/10.1021/ed019p230