[HN Gopher] Using copper to convert CO2 to methane
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Using copper to convert CO2 to methane
Author : MilnerRoute
Score : 47 points
Date : 2024-07-07 17:22 UTC (5 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| bloopernova wrote:
| I am having trouble understanding the details here.
|
| How expensive is this process?
|
| Is it feasible to scale this?
|
| Are other catalysts better than this one at producing methane
| from CO2?
| catlikesshrimp wrote:
| This is a publication about a finding. No price yet, no
| bussiness yet
|
| The current synthesis process starts with oil. I imagine
| through hydrogenation.
|
| The idea here is producing methane as a battery. A solarfarm
| would be upgraded to a power plant that generates electricity
| all day. That's it
| SoftTalker wrote:
| > A solarfarm would be upgraded to a power plant that
| generates electricity all day. That's it.
|
| That's it, but that would be incredibly valuable, as the big
| downside of solar is that it only works during the day, and
| only really works for the peak part of the day, maybe 6-8
| hours depending on where you are.
|
| The question will be is this process to store solar energy as
| methane cheaper (bottom line, i.e. accounting for losses in
| turning it back into electricity later) than storing it in
| batteries.
| cyberax wrote:
| Some countries (Germany) need a way to store enough energy
| for several _weeks_ of consumption. This is prohibitively
| expensive for batteries.
| math_dandy wrote:
| What approaches to storage are viewed a as most
| promising? Is Germany building anything out yet or
| testing at scale?
| tonyarkles wrote:
| In general, from my own efforts to try to understand the
| answer to that question, pumped hydro storage is probably
| the most promising but it'll only work in places that
| have the geography for it. There are a couple of
| excellent examples in Scotland,
| https://en.wikipedia.org/wiki/Cruachan_Power_Station is
| one. The trick is that there's a 400m drop; lots of
| places won't have the geography to get that much head.
| cyberax wrote:
| In Germany? So far it has been mostly magical thinking.
| It has almost infinite capacity
|
| Realistically, long-term hydrogen storage is the only
| technology that is even remotely feasible. There are
| several demonstrator projects ongoing right now. I'm
| personally not too optimistic about them.
| derriz wrote:
| Germany has been the biggest exporter of electricity in
| the world in 8 of the last 10 years. Germany also has one
| of the most reliable grids in the world in terms of
| system interruptions - as measured by SAIDI - with less
| than 15 minutes of interruption per customer year -
| significantly more reliable than France for example.
| They've managed to keep the lights on after going
| completely cold turkey on Russian gas in the space of
| less than a year - a remarkable feat which has been given
| no credit by most German energy policy critics who have
| been confidently predicting energy Armageddon in such a
| scenario.
|
| Not to say that there are no grounds for criticizing
| German policy but most of the criticism seems to be
| politically motivated rather than based on specific
| failures of the policy.
|
| Secondly, why hydrogen? It's a potent greenhouse gas -
| GWP100 of 12 or 13 times that of CO2. Yes it's less
| potent than methane but it's far "leakier" and more
| difficult to contain than methane as well as being more
| dangerous and difficult to handle. It cannot be combusted
| in air (most are suggesting mixing it with methane) in a
| domestic setting because of the 10 times as much NOx
| caused by the higher burning temperature. While all the
| infrastructure for methane/natural gas already exists
| including long term (seasonal) storage facilities, I see
| no compelling reason to spend 100s of billions to build
| all this new infrastructure to use a different warming
| gas for energy storage and transport.
|
| To be honest it's a minor issue in the grand scheme of
| things - keeping natural gas around to cover the last 10%
| of electricity generation is no big deal as the world
| rushes to electrify the other activities which currently
| release large amounts of CO2. The focus should be on
| getting to that 80-90% carbon-free electricity and the
| electrification of as much as is possible of pollution
| sources like domestic heating/cooking, transport and
| heavy industry.
| SoftTalker wrote:
| Good point, any country at high lattiudes will need this
| during the winter.
| lottamus wrote:
| I'm not sure how effective using copper will be at scale, though
| I know you can use h2o and co2 to produce ch4 (methane) through a
| process called a Sabatier Reaction which involves the presence of
| a catalyst like nickel and high temperature. I'm guessing it
| would be a similar process here, except with copper?
|
| Additionally, I recently discovered a company Valar Atomics who
| are working on small scale nuclear reactors to produce methane
| from h2o and co2 using this method.
|
| - Valar Atomics announcement
| https://x.com/isaiah_p_taylor/status/1720418162985054350?s=4...
| catlikesshrimp wrote:
| Sabatier uses hydrogen. As an intermediate, it might be less
| efficient (and dangerous?) H2O -> H2 + O2| H2 + CO2 -> CH4 +O2
|
| The idea is not new, but it is not bad
| https://en.m.wikipedia.org/wiki/Power-to-gas
| bell-cot wrote:
| 'Tis a sad day when a phys.org article is this fluffy. Much
| better is the research article's Abstract:
|
| > Carbon dioxide offers a unique opportunity as a feedstock for
| energy production through electrocatalysis. Methane production
| holds promise for its widespread applications and market demand.
| However, commercial viability faces challenges of low
| selectivity, current density, and high applied potential. Efforts
| to improve methane selectivity while suppressing multi-carbon
| products, e.g., ethylene, often involve lower alkalinity
| electrolytes. However, it reduces current density due to
| increased ohmic resistance without significant gains in the
| reaction yield. This study utilizes quantum mechanics
| computations to design a nano-cluster copper catalyst that
| redirects the reaction pathway from ethylene towards methane,
| even under alkaline conditions. We achieved a Faradaic efficiency
| (FE) of 85 %, a current density of 1.5 A/cm2, and stability of
| over 10 hours solely by controlling particle size in copper
| catalysts. This work paves the way to overcoming current
| limitations in electrocatalytic methane production and holds
| broader implications for advancing sustainable CO2 utilization in
| energy systems.
|
| Also of interest - could this electrochemical setup be run in
| reverse, as a methane fuel cell? That I'm aware of, 85%
| efficiency would be far better than the current state of the art
| there.
| marcosdumay wrote:
| Why would you need something that complex in a fuel cell? You
| don't need high selectivity.
|
| AFAIK, ceramic membranes work perfectly well as exchange
| elements for hydrocarbon-oxygen fuel cells; but I have no idea
| why they aren't being used everywhere. It used to be mostly due
| to longevity issues, but I haven't kept up.
|
| Also, Faradaic efficiency is not the total efficiency. For a
| fuel cell it would automatically be close to 100% anyway, while
| total efficiency is normally much lower.
| bryanlarsen wrote:
| AFAICT there are 3 broad steps for creation of "green" methane.
|
| - creating H2 from H2O - concentrating CO2 from either the
| atmosphere or the waste products of an industrial process such as
| cement production - creating CH4 from the H2 and the CO2. AKA
| Sabatier.
|
| This paper uses H2 as an input, so is only talking about the last
| step. A cheaper/better Sabatier is nice, but AFAICT it's the
| least expensive step of the three.
| blueflow wrote:
| Doesn't pass basic thermodynamics.
|
| If this finding is worth it, strap the machine doing it onto a
| car with methane motor (already exists) and you'll have an
| Perpetuum mobile.
| cfgauss2718 wrote:
| Nothing about this research violates conservation of energy.
| The article as written is advocating using excess solar or wind
| energy as input to this CO2->CH4 conversion process (which is
| electrolysis based) so that some of that energy can be reused
| later by burning methane. Later, as in when the wind isn't
| blowing or the sun is t shining.
| hannob wrote:
| I had recently written a detailed article about e-methane,
| including how it compares to other hydrogen derivatives. tl;dr is
| that there are a lot of doubts whether e-methane makes any sense,
| as you usually end up either preferring hydrogen directly, or, if
| you need something with a carbon atom, you likely will use
| methanol.
|
| Here's the article: https://industrydecarbonization.com/news/is-
| there-a-place-fo...
|
| I had posted it on HN, but didn't get upvoted.
| Animats wrote:
| Actual title: "Using copper to convert CO2 to methane could be
| game changer in mitigating climate change".
|
| Is there demand for methane? Why are there so many methane flares
| at oil wells in Texas, then?
|
| At the rate solar, wind, and batteries are coming along, carbon
| capture is a waste of time and resources. Price alone is going to
| eliminate most demand for carbon based fuels. This is happening
| much faster than expected. See last week's Economist.
| passwordoops wrote:
| >Why are there so many methane flares at oil wells in Texas,
| then?
|
| Flaring is more cost effective at current prices
| tonyarkles wrote:
| Yeah, my understanding is that there's a couple of moving
| parts for that:
|
| - Methane is 28x more potent as a greenhouse gas than CO2 is.
| I'm rusty on my chemistry but it seems like CH4 + 2 O2 => CO2
| + 2 H2O, so by flaring it you're getting a 28x reduction in
| GHG potential even though it looks bad seeing it burning like
| that.
|
| - The infrastructure isn't in place to harvest, liquify, and
| transport methane from oil fields. Oil itself is relatively
| easy to transport away from oil fields to refineries, while
| natural gas needs near-site processing to turn it into a
| liquid and keep it compressed. You also would need to build
| out (smaller) pipelines to transport it from the oil field to
| the existing natural gas handling infrastructure which may
| not be nearby.
|
| It's one of those things where it's basically free coming out
| of the well but a big investment would be required to capture
| it and, assuming you're going to be pulling the oil out
| anyway, burning it is better for the environment than just
| venting it.
|
| Edit: I do recall recently reading about some tech though
| where they were going to start using it on-site for fuel for
| equipment. I think it was for on-site generators instead of
| using electricity from the grid, but I don't have a link
| handy.
| Animats wrote:
| That would be Giga Energy.[1] They co-locate containerized
| Bitcoin mining systems with wells that produce excess
| natural gas and methane, burn the gas for power, and export
| bitcoin. Really.
|
| [1] https://www.gigaenergy.com/
| actionfromafar wrote:
| There is one like that which runs compute (read Nvidia
| cards).
| adastra22 wrote:
| That would kinda suck as a user as these things are
| notorious for switching on and off as gas is available
| (which isn't constant). For bitcoin miners that doesn't
| matter, but if I was running a long compute job...
| actionfromafar wrote:
| Yeah, I have no special insight, I just thought it was
| interesting. Remembered the name now, Crusoe:
|
| https://www.crusoe.ai/blog/turning-waste-into-power-
| crusoes-...
| triceratops wrote:
| I thought that we need to do both - stop emitting and clean up
| historic emissions - to keep climate change in check. Zero
| emissions won't happen for a very long time, unless everyone is
| ok with giving up air travel and a few other modern
| conveniences. Is carbon capture really pointless?
| westurner wrote:
| How are they planning to produce methane for return flights
| from Mars? There is Copper on Mars.
|
| "Copper nanoclusters: Selective CO2 to methane conversion
| beyond 1 A/cm2" (2024)
| https://www.sciencedirect.com/science/article/pii/S092633732...
| thriftwy wrote:
| Methane is a fossil fuel replacement. A good fraction of
| Moscow's bus fleet run on methane. In general, ICEs run just
| fine on natural gas as gasoline replacement.
| alostpuppy wrote:
| Can it be used in liquid form somehow?
| adastra22 wrote:
| https://en.wikipedia.org/wiki/Liquefied_natural_gas
| _Microft wrote:
| What is known as "natural gas" is chemically mostly methane if
| that helps with answering your question.
|
| From what I know it is just cheaper to flare natural gas that
| occurs as _byproduct_ of oil production than to deal with it
| otherwise.
| adastra22 wrote:
| Methane is also known as "natural gas," the thing which burns
| in your range stovetop or powers your water heater. When
| liquified it is known as Liquid Natural Gas or LNG. You may
| have heard of that.
|
| In general, starting from methane you can then work your way up
| to all sorts of various hydrocarbons like gasoline or jet fuel.
|
| Methane is also the propellant of SpaceX's Starship. If they
| launch as frequently as they want to launch, Elon will likely
| invest in local zero-carbon production of methane using
| techniques like the OP.
| trhway wrote:
| Water + CO2 into methane and oxygen. Hopefully just in time for
| the SpaceX Mars mission.
| greenthrow wrote:
| This is nonsense. There's not enough demand for methane and
| methane itself is an even worse greenhouse gas than CO2.
| actionfromafar wrote:
| True about methane being questionable in itself, but converting
| methane to gasoline would be very useful.
|
| https://en.m.wikipedia.org/wiki/Gas_to_liquids
| dzhiurgis wrote:
| Gasoline in era of EVs is nuts.
|
| Liquified natural gas might still have few decades for
| certain industries, but with electrification underway for
| pretty much everything all these processes seem pointless.
|
| Sure you could capture CO2 from a plant, liquify, ship to
| where sun shines, convert to CNG, then ship back. Or you
| could just build power lines.
| adastra22 wrote:
| Plastics (a petroleum product) are not useless.
| dzhiurgis wrote:
| Ok that's fair. Can they made by oil byproducts only or
| can it be eventually synthesised from CO2?
| actionfromafar wrote:
| You can synthesise basically anything from CO2 and
| hydrogen. You can get syn-crude which can the be treated
| the same as regular crude. If we had "unlimited"
| electricity we could make basically anything from air and
| water.
| adastra22 wrote:
| Global methane (aka LNG) demand is over $100 billion per
| year...
| Someone wrote:
| FTA: _"Our top finding was that extremely small copper
| nanoclusters are very effective at producing methane, " continues
| Salehi. "This was a significant discovery, indicating that the
| size and structure of the copper nanoclusters play a crucial role
| in the reaction's outcome.""_
|
| How can that be surprising for _"a new catalyst for converting
| carbon dioxide (CO2) into methane"_? Are there any catalysts
| where their effectiveness doesn't increase with surface area?
|
| Also, if they make them tiny ( _"we used copper catalysts with
| different sizes, from small ones with only 19 atoms to larger
| ones with 1000 atoms"_ ), how do you make sure you don't pump out
| the catalyst with the methane? A filter?
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