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Maybe I'm missing something, but it seems like the plan is to use this hydrogen in combination with CO2 captured from the air to make methane. If so, the hard
by rgmerk 3y ago
Maybe I'm missing something, but it seems like the plan is to use this hydrogen in combination with CO2 captured from the air to make methane.
If so, the hard part is getting the carbon capture cheap enough, not the hydrogen.
I crunched the numbers and you need around 13.6 kilograms of carbon and 4.54 kilograms of hydrogen to make enough natural gas to give you 1GJ of heat when combusted (this is how natural gas is priced in the metric world - 1 GJ is roughly 0.95 MMBTU).
If you're extracting CO2 from the air, roughly 27% of the CO2 is carbon, the rest is oxygen.
Doing the maths suggests that at current ballpark prices for CO2 direct air capture of $1000/tonne, the cost of capturing enough CO2 to make a GJ of natural gas is about $50. That's before you've done the processing to convert your CO2 and hydrogen into natural gas and oxygen.
So let's assume an order of magnitude improvement in air capture costs. Even at $100 per tonne, the CO2 capture cost is around $5. When you combine that with the approximately $4.50 worth of hydrogen required, that gives an input cost of around $9.50. That's way more than domestic natural gas currently costs in the US, but it's in the ballpark that you could subsidise your way around that at scale, and the numbers look pretty reasonable compared to imported LNG in Europe and Asia.
So to me this suggests that, if your business plan is to make methane, the hydrogen part is almost a sideshow to getting direct air capture costs down.
- pfdietz 3y agoOr, just use the hydrogen as-is, in stationary power plants. Hydrogen can be burned in combustion turbines just like methane; why add the extra step? At $1/kg, the fuel cost of a combined cycle power plant will be $0.05/kWh. Hydrogen is quite storable underground (just like natural gas). At this fuel cost, new construction nuclear is hopelessly uncompetitive, even for base load generation. And unlike nuclear, the hydrogen burning CC plants can be economically dispatched, turned down/off when renewables or short term storage are directly powering the grid.
- rgmerk 3y agoSure, if you're only using it as storage in a largely electrified economy. The attraction of synthetic methane is that it is 1) transportable in existing pipelines, including to millions of homes and small businesses. 2) usable in literally millions of existing devices 3) relatively easy to ship. None of those things are true for hydrogen.
- chii 3y agoso the question becomes whether it's harder to improve CO2 capture, or to make transporting and using hydrogen (ala, build out new or improve existing pipes, machines etc). I would imagine that improving CO2 capture is "easier", because it requires fewer people to cooperate. Existing infrastructure replacement/improvements will need large numbers of people to agree on what, who and how. And you know how that goes...
- pfdietz 3y agoIt's more efficient to burn hydrogen (or methane) in a combined cycle plant and use that power to drive heat pumps in homes and businesses, than it would be to burn that fuel in furnaces there. As an added bonus, you can often drive those heat pumps directly from renewable sources without the conversion cost of electrolysis (and for methane, DAC and methane synthesis.) Methane also has the probably unavoidable problem of leaks in the distribution network. It's a strong greenhouse gas; even small leaks are very problematic.
- rgmerk 3y agoYes, I agree, and am of the view that the widespread distribution of piped gas (hydrogen, methane, or blends thereof) to homes and small business is going to be phased out for the reasons you describe. But you can see why some people are trying to make a drop-in, clean-ish (modulo fugitive emissions) replacement for fossil gas.
- angiosperm 3y agoIncidentally, leaked hydrogen is substantially worse, as a greenhouse gas, than methane.
- jqpabc123 3y agoOr, just use the hydrogen as-is Or, just use the solar electricity as-is. I understand the energy storage aspect here but it comes at a high cost. One battery breakthrough will obsolete this entire process. Lots of time and money is being devoted to new battery technology --- very little to this. This effectively looks like a long shot effort to salvage the internal combustion engine.
- ClumsyPilot 3y ago> One battery breakthrough will obsolete this entire process Certainly, in year 2060 when it's too late. I can't help thinking that peolle who believe in Rapture have a similar thought process - if you are holding out for a miracle, it doesn't make sence to put in effort now
- jqpabc123 3y agoCertainly, in year 2060 when it's too late So when will this hydrogen thingy will be ready and economically viable? Don't look now but you might have just as big (if not bigger) case of religion.
- qwytw 3y agoSo investing it both would be the beast approach (using a ratio based cost effectiveness, viability etc. estimate)?
- jqpabc123 3y agousing a ratio based cost effectiveness, viability etc. estimate Isn't this sorta how the "free market" works? People/corporations invest money based on their judgement of viability, effectiveness, etc.. Right now, the majority of the collective mind trust is betting on new battery technology. But feel free to convince them otherwise.
- pfdietz 3y ago
- Gasp0de 3y agoThat's highly inefficient though, and therefore negates all the cost savings in the process before. How much efficiency can you get out of burning stuff, 40% of the stored energy?
- pfdietz 3y agoCombined cycle powerplants are > 60% efficient (LHV). The LHV of hydrogen is 33.3 kWh (of heat) per kilogram. Yes, it would be inefficient overall. And it's still cheaper than nuclear. Throw in a large fraction of energy not going through hydrogen (direct to grid, or through batteries) and the cost would be even lower.
- specialist 3y agoYes and: Startups like ETFuels are decarbonizing other industries, like transportation and fertilizers. We'll need all the solutions. Not either-or, but yes-to-all-and-more-of-it-please.
- pfdietz 3y agoThe space of solutions includes ideas that are ludicrous. We don't need all the solutions, we need some of the solutions that make sense. And you can't presuppose for any solution that it will fall in the sensible-and-not-ludicrous part; you have to argue why that would be. For new construction nuclear, for example, it's not at all clear building any more will make sense.
- rocqua 3y agoThe storage, transport, and existing infrastructure and machinery that already uses natural gas makes it much more attractive as a fuel. It sure isn't efficient. But with energy sources that are intermittent and have no ability to scale up for demand, we will have a lot of intermittently very cheap energy. Anything that can use this intermittent power is valuable, because we will need overcapacity to handle the low-wind, low-sun moments
- bertil 3y agoThere are countless opportunities to capture the CO2 from industrial applications, not from the air. I’m hoping that many of them will be replaced by carbon neutral option soon, but things like burning domestic waste might not disappear soon. I’m not sure how expensive it would be for it to be clean and pure enough, or what purity that process would need, but most of the cost you mention would be solved by colocating with a burner plant.
- coderenegade 3y agoThe most sensible option would be to store the hydrogen geologically and burn it directly if you needed the power. If you want something transportable, methanol is the simplest fuel you can make, and is what typically gets used when fossil fuels aren't an option (e.g. Germany in WWII). No need for carbon capture, since any source of carbon will do, and plants will pull carbon out of the atmosphere as long as you run carbon negative.
- Gasp0de 3y agoBurning hydrogen sounds like a highly inefficient process.
- dmurray 3y agoThe third part of the article compares their approach with an alternative of extracting hydrogen from methane, so they definitely aren't focused on using hydrogen to produce methane.
- rgmerk 3y agoFrom the introduction to the linked blog post: “ We’re developing a scalable electrolyzer to deliver the cheapest possible green hydrogen, which we use as a precursor chemical to make cheap synthetic carbon neutral natural gas in our Terraformer.”
- hedora 3y agoOf course, if you have inexpensive direct air capture of CO2, and a way to permanently store the carbon (e.g, as a block of coal, or by injecting CO2 deep under ground), then all of a sudden, burning fossil fuels can be made climate neutral. If the cost of sequestering the CO2 and pumping + refining oil / natural gas is less than the cost of capturing H2 and using it to synthesize fuel with the CO2, then the synthetic fuels are a dead end. (Until we run out of oil, but that will he centuries from now.)
- bannedbybros 3y ago[dead]
- alexchamberlain 3y agoYou could simply build one of these plants next to a concrete plant, which is producing highly concentrated CO2 to reduce that cost. (A lot of similar industries exist of course.)
- rgmerk 3y agoThey’re saying that the synthetic gas will be carbon neutral. If you’re capturing CO2 that comes from an industrial process like cement production, turning it into methane, burning the methane, and releasing the combustion products into the atmosphere, from an accounting point of view either the gas isn’t carbon neutral, or the cement plant isn’t carbon neutral, and the process is still incompatible with achieving net zero emissions.
- alexchamberlain 3y agoYes, I agree. On the other hand, - we need concrete, steel and other similar materials to build the transition to clean energy. * - we need to be able to store (and ideally transport energy) from renewable, intermittent sources, such as solar, and sources that are hard to turn off/control, such as nuclear and wave power. Although this doesn't solve all the carbon emissions, concrete production accounts for >5% of carbon emissions IIRC and energy production a whole load on top of that, so if this can make a significant dent whilst stopping some of the other environmental side effects of drilling for Nat Gas, is this not a significant step forward? * The Material World by Ed Conway is a really interesting read that explores some of these tradeoffs
- benj111 3y agoIsn't that like saying EVs aren't green because the electricity isn't. I'd say in this situation that the hydrogen is green, but the cement isn't. It's still capturing Co2 that would otherwise be in the atmosphere. Although I'm sure the cement manufacturers will let you know about the CC and imply its green. The cement company can still do its own thing to become carbon neutral.
- rgmerk 3y ago
- specialist 3y ago> If so, the hard part is getting the carbon capture cheap enough, not the hydrogen. You might be interested in ETFuel's strategy. "Making shipping fuel with off-grid renewables" [2023-06-28] https://www.volts.wtf/p/making-shipping-fuel-with-off-grid#details https://www.volts.wtf/p/making-shipping-fuel-with-off-grid#d... TDLR: Combo of solar and wind for power, CO2 from industrial sources, create fuels (methane, methanol, amnonia). Use pipes or trucks as needed. ETFuels' "secret sauce" is integration and creating fuels. They'll use best available option for electricity and CO2. They'll build where it makes most sense to optimize opex. In the future, once direct-air capture becomes cost competitive, no problem. Also, I'm certain they'll also adopt advanced geothermal, in combination with solar and wind, to solve their electricity problems as well as greatly expand where they can feasibly deploy.