Methane cracking: Difference between revisions
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|Methane cracking | |Methane cracking | ||
|Best technologies so far | |Best technologies so far | ||
| | |__ {{p|to be filled in soon}} | ||
|- | |- | ||
|'''Not''' methane cracking | |'''Not''' methane cracking | ||
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There have been some green initiatives to use ''non-fossil-fuel energy'' to crack methane. However, this is only worthwhile if the efficiency is better than non-methane-cracking ways to make hydrogen (see table). | There have been some green initiatives to use ''non-fossil-fuel energy'' to crack methane to make hydrogen gas. However, this is only worthwhile if the ''efficiency'' is better than non-methane-cracking ways to make hydrogen (see table). | ||
Above 100%, you | Above 100%, you don't need any ''non-fossil-fuel energy'' for it to be green. Just burn some of the hydrogen to keep cracking the methane. Sadly, this has never been achieved. | ||
In the ideal case, fossil fuels could power the entire world with zero carbon emissions. At least, until [[peak oil|oil and gas reserves run out]]. | In the ideal case, fossil fuels could power the entire world with zero carbon emissions. At least, until [[peak oil|oil and gas reserves run out]]. | ||
Revision as of 00:20, 31 May 2022
Energy viability
Every methane-cracking method invented so far is a net loss of energy. Meaning that it takes more energy to crack the methane than you ultimately get from burning the hydrogen. But in theory, this need not be true:
- CH4 -> C + 2 H2 (endothermic: 74.850 kJ/mol)
- 2 H2 + O2 -> 2 H2O (exothermic: 285.820 kJ/mol)
Hydrogen production efficiency comparison
| Type | Method | Energy out / energy in |
|---|---|---|
| Methane cracking | Theoretical best case | 382% see chemistry equation above |
| Not methane cracking | Electrolysis of water | 80% |
| Methane cracking | Best technologies so far | __ to be filled in soon |
| Not methane cracking | Heat -> turbine -> electrolysis of water | 25% |
There have been some green initiatives to use non-fossil-fuel energy to crack methane to make hydrogen gas. However, this is only worthwhile if the efficiency is better than non-methane-cracking ways to make hydrogen (see table).
Above 100%, you don't need any non-fossil-fuel energy for it to be green. Just burn some of the hydrogen to keep cracking the methane. Sadly, this has never been achieved.
In the ideal case, fossil fuels could power the entire world with zero carbon emissions. At least, until oil and gas reserves run out.