Never trust anything written by lawyers/economics/MBAs on climate change - only analysis by chemical or mechanical engineers is worth reading.

Methane pyrolysis is an old technology from early days of oil refining for production of hydrogen & Ammonia/fertilizer/Methanol. it yields half as much H2 than SMR/ATR so it can't compete on cost, unless there is carbon tax/CO2 penalty. Also, coke produced by pyrolysis is lower quality than that produced by Delayed Coking of crude oil refining.

Most of the comments seem to confuse pyrolysis (no O2) with reforming (H2O), which produces CO2. ATR uses partial O2 & H2O and is more energy efficient & cheaper.

Commonsense should tell you e- generated by H2 can't compete with CH4, because Ch4 is the feedstock & H2 is the product!

Interesting to see this on the HN front page. On the subject of methane pyrolysis, it turns out if you look at the Gibbs free energy calculation, about half of the energy of methane combustion is released from the formation of water, and the other half from the formation of carbon dioxide. That suggests that if you can be efficient with conserving the heat of pyrolysis, you can make a methane power plant that starts with a pyrolysis step to separate out the carbon atoms in an oxygen-free environment, and then burn the remaining hydrogen to power the cycle, and the end result would be a zero-emissions natural gas power plant. It would require twice as much gas to run, but if you can find a good value-added use for the carbon, it could potentially still be cost effective.

This would probably be much more efficient than doing pyrolysis to extract the hydrogen for use in electricity generation somewhere else, because you don't lose the substantial stored heat energy in the process of cooling that hydrogen back down.

And I can't help but wonder if fossil fuel companies might suddenly start endorsing aggressive zero-emissions targets if there's a way for this to double the demand for their products, rather than eliminating it.

It requires more input energy, but it's been really good to see electrolysis of H2O for hydrogen generation take off. There are honestly industrial/grid scale operations actually starting now (as opposed to being constructed). E.g. Aces Delta in Utah. 220MW of wind/solar as input (i.e. equivalent to power for a medium sized city) As a disclaimer, my wife works on that project, but I think it's incredibly cool regardless.

Pyrolysis is a less energy intensive way to produce hydrogen, and does deserve more attention. But it still requires methane as a feedstock.

Hydrolysis let's use use hydrogen as essentially a fixed loss battery. It's perfectly complimentary to seasonally variable renewables like wind and solar. Batteries have too high of a loss though time for seasonal or multi-year storage. If you can store it (big if... Not everywhere has a salt dome like Delta, UT), hydrogen really is a great solution.

This comes up on a regular basis in the discussion around hydrogen, sometimes it's also known as turquoise hydrogen. The claims made here are very misleading, let me quickly explain why.

The idea here is that you make hydrogen from fossil methane by splitting it into hydrogen and carbon. Now, the claim is that you now have "clean" or "climate neutral" hydrogen. But it's made from fossil gas, and there's carbon. If you would now bury that carbon or do something else that guarantees that carbon never ends up in the atmosphere, ok, you might claim that. (Still with caveats: your fossil gas production has upstream emissions you need to account for.)

But that is not economically feasible. So the idea is: sell that carbon as a co-product. But now, that carbon will in almost all cases eventually still end up as CO2 emissions. But these pitches never talk about that. Claiming that hydrogen is "climate neutral" is, then, more an accounting trick. If you are honest, you would have to do something like associate half of the eventual emissions to it.

I wrote about it in more detail before: https://industrydecarbonization.com/news/the-problem-with-tu...

Hydrogen isn’t “clean” in any sense and I dislike that adjective is used so commonly with hydrogen.

When burned in air it produces far more NOx than burning methane due to higher temperatures. For example, one popular idea (hydrogen blending - HENG) is to mix it into the natural gas people burn in their homes. But burning a 15% hydrogen blend leads to a ten fold increases in health damaging NOx over burning natural gas.

And leakage during transportation is much worse than NG - particularly in liquid form. Combined with fact that leaked hydrogen is an extremely potent (indirect) greenhouse gas with more and more studies arriving at a number between 10 and 13 for its GWP100 (https://cicero.oslo.no/en/hydrogen-leaks-add-to-global-warmi... for example).

Some back of the envelope calculations from fellows I work with suggested that the waste heat from a single gas turbine exhaust could supply enough H2 for 3 gas turbines - so a CC power plant with 3 gas turbines, 2 with standard HRSGs that use the exhaust gas to run a steam turbine, and the 3rd using the exhaust heat to run a methane pyrolysis process, would be the preferred configuration. Slightly less efficient, but 0 carbon emissions. The biggest issue would be running the plant at varying loads - you would need storage for excess H2 to run more efficiently.

Splitting methane to get hydrogen and carbon seems like exactly the wrong direction to move. Just because we like the idea of hydrogen fuel?

Monolith was the first mover here, they are making carbon black for Goodyear. Last year they were running into problems meeting targets for a $1B DOE loan, haven't seen if they've managed to get on track.

https://www.wsj.com/business/energy-oil/a-high-profile-clean...

Hydrogen is dead. It was a perfect example of green washing - even Greenpeace (Greenpeace Energy)(Green Planet Energy) was using it to greenwash import fossils to Germany from russia.

If there is a good, easy way to generate methane using atmospheric CO2, then, we could have a chemical battery in the form of methane, which is far easier to handle than Hydrogen.

But I wonder what the round trip efficiency of such a system would be. Current lithium batteries have it at around 80%

Is there some reason this wasn't done 100 years ago? 50? 30?

Methane outgassing/flaring from oil extraction operations has been going on the entire time we've been oil drilling. Why didn't the oil companies extract this resource?

And who is c3es? Wikipedia says they are a rename from the Pew Center for Global Climate. It may be a logical fallacy to question the motives of an argument, but it isn't a policy fallacy to know the motives.