3 ms·

I'm not entirely convinced about the rationale for hydrogen, but I'll play devil's advocate. If you burn the CH4 at the place of extraction, then you need a way

I'm not entirely convinced about the rationale for hydrogen, but I'll play devil's advocate. If you burn the CH4 at the place of extraction, then you need a way to transport the electricity. This is a hard problem. You can instead ship the natural gas via pipes (or LNG) to some other place, close to the consumer, where it will be burned in a power plant. For this option, there will be leaks proportional to the distance the gas is shipped. A pipeline 100km long will leak 10 times more than a pipeline 10km long. When the famed analysis that claimed 3.5% average CH4 leakage came out, they simply did not consider the length of the pipe. If you instead immediately convert the CH4 into H2, and ship that via pipes, then you have no reason to have CH4 leaks beyond a tiny amount associated with the extraction itself (which would be there even if you decide to convert the gas into electricity on the spot). So, all in all, there's a case to be made that the conversion of CH4 into H2 would result in great reductions in overall greenhouse gas emissions.

HALtheWise 5y ago
I don't understand why the leak rate from H2 pipes wouldn't be as bad as CH4. In fact, shipping hydrogen is generally much harder, since it requires such deeply cryogenic temperatures to stay liquid, unlike liquid natural gas which can be accomplished with just pressure.
- credit_guy 5y ago
  H2 is not a greenhouse gas. The leak of H2 does not contribute to global warming.
  - rrrrrrrrrrrryan 5y ago
    If you burn a greenhouse gas to create H2, and then X% of the H2 goes to waste through leakage, it's possible this process may contribute more to global warming than just transporting and burning the greenhouse gas itself, depending on X. If X is very large, you could argue that the leak of H2 does contribute to global warming.
JimTheMan 5y ago
The pipeline is welded the full length, so a linear leak rate doesn't really make sense. Where it could leak would be at valve station flanges, which by code are required every X km depending on the land risks. You can test to see whether the flanges are leaking, and you can tighten accordingly in most cases. Effectively this leaking can be avoided in a transmission/industrial sense with the right amount of applied effort.

HALtheWise 5y ago

I don't understand why the leak rate from H2 pipes wouldn't be as bad as CH4. In fact, shipping hydrogen is generally much harder, since it requires such deeply cryogenic temperatures to stay liquid, unlike liquid natural gas which can be accomplished with just pressure.

credit_guy 5y ago
H2 is not a greenhouse gas. The leak of H2 does not contribute to global warming.
- rrrrrrrrrrrryan 5y ago
  If you burn a greenhouse gas to create H2, and then X% of the H2 goes to waste through leakage, it's possible this process may contribute more to global warming than just transporting and burning the greenhouse gas itself, depending on X. If X is very large, you could argue that the leak of H2 does contribute to global warming.

JimTheMan 5y ago

The pipeline is welded the full length, so a linear leak rate doesn't really make sense. Where it could leak would be at valve station flanges, which by code are required every X km depending on the land risks. You can test to see whether the flanges are leaking, and you can tighten accordingly in most cases. Effectively this leaking can be avoided in a transmission/industrial sense with the right amount of applied effort.