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 | 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 | |title=Lecture experiment on the synthesis and combustion of ammonia | ||
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|url=https://pubs.acs.org/doi/abs/10.1021/ed019p230 | |url=https://pubs.acs.org/doi/abs/10.1021/ed019p230 | ||
}}</ref> | }}</ref> | ||
====platinum==== | |||
===High Pressure=== | |||
====platinum==== | |||
* Yield: 4-5% | |||
====promoted iron==== | |||
* The catalyst is doped purified iron {{#Chem: Fe + CaO + K2O + SiO2 + Al3O4}} | |||
* The reaction takes place at 300–550 °C and 50–250 atmospheres. | |||
* Yield is over 90% | |||
The gases 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. | ||
Latest revision as of 16:06, 13 July 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 gases 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