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Methane cracking: Difference between revisions
→Hydrogen production efficiency levels
(Created page with "==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:<br /> : CH4 -> C + 2 H2 (endothermic: 74.850 kJ/mol)<br /> : 2 H2 + O2 -> 2 H2O (exothermic: 285.820 kJ/mol) ===Hydrogen production efficiency levels=== {| class='wikitable' ! Type ! Method ! Energy out / energy in |- |Methane c...") |
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: 2 H2 + O2 -> 2 H2O (exothermic: 285.820 kJ/mol) | : 2 H2 + O2 -> 2 H2O (exothermic: 285.820 kJ/mol) | ||
===Hydrogen production efficiency | ===Hydrogen production efficiency comparison=== | ||
{| class='wikitable' | {| class='wikitable' | ||
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|Methane cracking | |Methane cracking | ||
|Theoretical best case | |Theoretical best case | ||
|382% | |382% {{p|see chemistry equation above}} | ||
|- | |- | ||
|'''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 | 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). | ||
Above 100%, you | Above 100%, you can keep the system going without any ''non-fossil-fuel energy'' inputs. Just burn some of the hydrogen itself to crack the methane. | ||
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]]. | ||