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!
> 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.
Sounds like never trust anything written by chemical or mechanical engineers on costs, only economists/MBA :) ?
To be competitive on cost, not only the percent of used input should be taken into account, but also how much the one and another ways of processing are costing independently. If old technology methane pyrolysis produces half as much H2 but is quarter as cheap per unit of H2, it still wins whatever modern method is.
Just so we know if we should keep reading, which one are you?
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.
It's not appropriate to call it "technology," in the same way it's not appropriate to call "combustion" a "technology." There's a very wide variety of technological solutions to realize this family of chemical processes, and some are going to be better than other, depending on the use case or scenario. The report actually covers those pathways reasonably well.
Also, coke produced by pyrolysis is lower quality than that produced by Delayed Coking of crude oil refining.
Ideally, you would not be producing coke at all, but a higher value material. However, even coke will be of much higher purity than petcoke (before calcining) -- i.e. it would be intrinsically zero-sulfur carbon material, - but I'm not sure what applications it would have that don't involve production of CO2.
But obviously the carbon co-product should have value, which would provide a cost offset to the hydrogen. With a high-quality co-product (> $1/kgC), this offset would be significant enough to provide that hydrogen essentially free of charge.
SMR and ATR generate significant amounts of CO2 (~10 kgCO2/kgH2), which does not provide a cost offset, and in a fair world would instead incur a significant added cost.
Electrolysis requires 4x more energy (also electric, not thermal) and does not have a marketable/valuable co-product. Just on the energy cost alone (50 kWh/kgH2 * 0.12 USD/kWh = 6 USD/kgH2 > 40 USD/MMBTU) electrolyzer hydrogen is not competitive with any of the above.
Commonsense should tell you e- generated by H2 can't compete with CH4, because Ch4 is the feedstock & H2 is the product!
Didn't parse this statement, sorry. Can you rephrase?
> Didn't parse this statement, sorry. Can you rephrase?
They might have meant something like: if you process A through B to C while you could also process A to C directly, then the latter direct process will usually be more economically viable.
While this heuristic sounds broadly reasonable, it neglects so many details of any real production processes and value chains that it seems hardly applicable to real world situations.
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.
About 70% of the energy is in hydrogen, 30% is in carbon. 1 GJ of methane weighs about 20 kg, 5 kg of which comprise hydrogen. At 142 MJ/kgH2 (higher heating value, which implies condensation of the produced water), 710 MJ out of that 1 GJ is due to hydrogen.
With a 60%-70% efficient hydrogen fuel cell, about 50% of the electricity generated from hydrogen from pyrolysis of methane would drive the process, and 50% could go into the grid.
Your accounting works if someone else does the pyrolysis for you and you're left with just the H2 and C at the end, but mine includes the energy consumed by the pyrolysis step that breaks the methane molecule (albeit neglecting any thermodynamic losses, which there will be several -- for example you need to recapture the heat carried away by the hot carbon atoms). On the other hand, you can hardly wish for a better feedstock for CVD diamond production...
Hydrogen is way more valuable for chemical production, especially fertilizer. That would be a way to use the excess heat you mention.
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.
So why is methane as feedstock a problem?
Isn't it better to spend less energy convert a ubiquitous, but environmentally harmful gas into hydrogen along with useful materials, than spend 4x more energy to convert a critical resource -- fresh water -- into hydrogen without any valuable by-products?
Yes methane is an environmental problem, even small methane leakages have a large GHG impacts. But the best way to deal with that environmental problem is to not pull it out of the ground in the first place
Plus for pyrolysis, you have to deal with the carbon which makes up 75% of the methane by weight. A non-trivial issue.
Which is really the stakes here: if you can "burn" fossil fuels without putting GHG in the air...there's no reason to stop using them at all. In fact we should vastly expand their use.
A lot of the methane leaks are not “leaks” but intentional releases to “protect” equipment or to simply get rid of it. Until there are fines on the pollution it won’t stop.
Right. https://en.wikipedia.org/wiki/Water_scarcity
You would want to use solar power for electrolysis. In the US, regions with abundant solar power are also the ones that: - have true water scarcity - Nevada and Arizona - have low population and industrial density, so any generated hydrogen would need transported to the point of use.
The bigger problem is the energy disparity. Electrolysis of water requires 50 kWh/kgH2 or more. Even a 70% efficient fuel cell would get ~25 kWh/kgH2 -- horrible roundtrip efficiency. With pyrolysis, that equation is exactly inverted: at 9-12 kWh/kgH2, you can generate excess electricity with no CO2 emissions.
Plus for pyrolysis, you have to deal with the carbon which makes up 75% of the methane by weight. A non-trivial issue.
Exactly. 20 kg of methane costs $3 today, but contains 15 kg of carbon that could be worth $20-$30. It's a non-trivial issue if you hate generating value.
First of all the US isn’t the whole world.
Like you said transportation is a problem which is why you would produce it close to where it’s needed (say Nebraska). You don’t need an “ideal” solar output location.
Yes I am well aware of the energy difference.
> Exactly. 20 kg of methane costs $3 today, but contains 15 kg of carbon that could be worth $20-$30. It's a non-trivial issue if you hate generating value
If carbon free hydrogen is going to be worth doing at scale it will be because there is a price on the carbon. So the input methane will go up in price.
As for the output, global demand for carbon black is currently ~14 million metric tones a year [0].
Current hydrogen demand is ~100 million metric tones a year [1].
100 Mt of hydrogen needs ~400 Mt of methane and produces ~300 Mt of carbon.
300 Mt vs 14 Mt of current demand. What do you supposed will happen to that carbon black price when you produce even a fraction of total hydrogen demand through pyrolysis?
It’s non-trivial cause you’re gonna be having to create reverse coal mines to store all that shit.
[0]: https://www.chemanalyst.com/industry-report/carbon-black-mar...
[1]: https://www.iea.org/reports/global-hydrogen-review-2025/dema...
Seems one forward step would be for countries that have an abundant source of alternative fuel to go for it and stop importing so much oil. Countries that don't have much water can import alternative energy sources or keep using the oil that they're rich in.
I’ve always been curious about generating methane in industrial composting or from landfills and using it onsite for hydrogen generation. Not sure if the generating capacity is enough though, there is probably a reason it isn’t being done.
There is inevitably leakage, and if even a small fraction does that it negates any global warming advantage on relevant timescales.
Any leakage from a pyrolysis plant is going to be negligible compared to what's undoubtedly already leaking from gas infrastructure installed in the 1950s (or earlier), as well as the continual accidental leaks caused by excavating.
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...
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).
Convert to hydrogen at point of use, and you can claim all the hydrogen hype without having to do all the hard things with hydrogen. If you accidentally oxidize methane instead of converting to hydrogen and oxidizing hydrogen, whoopsie-doodles, but it might be a simpler system.
It's probably a good move to "hydrogenize" the economy if we can, but it sure would be nice to move away from extraction into something that's more sustainably produced in-situ. Either electricity, or even methane synthesis.
Carbon black has the average CO2 intensity of almost 4 kgCO2/kgC [1] and its conventional production is so dirty and low-margin, that companies have been walking away from their plants rather than implement EPA-mandated upgrades. [2]
[1] https://static1.squarespace.com/static/5fd161c5b1bc2872873bd...
[2] https://www.ledger-enquirer.com/news/business/article2703292...
I get it - it's cool science and there's probably a couple of edge cases or whatever where this does make sense, but solar panels, batteries, and electric motors are all here and mostly work. The technology for all of that will continue to get better and make any hydrogen use cases even less practical. Just leave the oil in the ground.
Hydrogen is heavily used industrially, and today the most common and economical way it is produced is via steam reforming of methane, which emits CO2 as a byproduct. This method has the benefit of outputting solid carbon instead of CO2 while still being economically viable unlike most other ways of generating hydrogen.
You know which way we will not solve the problem?
By failing to recognize technologies that are going to help solve the problem.
It's the same with CCS.
The "green" mantra of "this is all just a strategy to help the fossil industry survive and we must boycott it" is shooting in one's foot.
As long as the world's energy infrastructure can not be built solely on renewables - which will still be the case in at least 2-3 decades - it makes sense to develop/use technologies that make the footprint of fossil energy smaller.
In 2015, the Department of Energy estimated that the CO2 footprint for production, processing, and pipeline transportation of natural gas averaged between 8 and 14 kgCO2-e per MMBTU of natural gas [1].
The average natural gas CO2 emissions (kgCO2/MMBTU) has been going down over time [2], and will be reduced even further in the next few years thanks to increasing fines [3] on one hand and financial incentives to reduce flaring and venting [4] on the other hand. A large percentage of these emissions are not due to accidental leaks, but are essentially intentional -- due to flaring, venting, and high-bleed controllers and actuators [2].
For an idea of how much emissions can be reduced, consider that the so-called certified gas has 90% lower CO2 footprint than the average today [5]. For example, the methane emissions for a natural gas utility in Oregon are 90% lower than EPA nationwide assumptions [6].
[1] https://greet.es.anl.gov/files/EERE-LCA-NG
[2] https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas...
[3] https://community.citizensclimate.org/resources/item/19/530#...
[4] https://www.epa.gov/inflation-reduction-act/methane-emission...
https://www.epa.gov/sites/default/files/2020-04/documents/us...
[5] https://www.cfindustries.com/newsroom/2023/bp-certified-natu...
[6] https://www.nwnatural.com/about-us/environment/less-we-can
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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.
https://www.wsj.com/business/energy-oil/a-high-profile-clean...
But I wonder what the round trip efficiency of such a system would be. Current lithium batteries have it at around 80%
Think about transporting peaks of renewables electricity generation that are not economically usable at the time when they're produced to times when renewables produce too little to meet demand. (Mostly in regions where generation depends significantly on seasons.)