Cascade reactions use nanoparticles to convert CO2 to complex molecules | Hacker News Reader

Cascade reactions use nanoparticles to convert CO2 to complex molecules

pubs.acs.org

46 pointsbookofjoe28 comments

Interesting although I’d love to see a discussion on the energy efficiencies as these catalyst aren’t free. CC (carbon carbon) and CH (carbon hydrogen) bonds are higher energy than CO (carbon oxygen) bonds. Hence why oxidizing (burning) carbon releases energy. You can’t reverse that reaction without an energy source.

So maybe this process or a similar process could be driven from a sustainable non combustion source.

The entire global economy is powered by burning stuff and first we need to figure out how to change that (the advances in wind and solar give me hope) then we need to generate enough excess power that we can start converting CO bonds back into CC or CH bonds.

Hate to say it, but it will never happen. Energy is a limiting resource - there will never be a time when we have "excess power". It would be tantamount to throwing money away - you'll never convince anyone to do that, and especially not while there are other people still burning things as it would amount to "subsidizing" those people's harmful behavior. Would you rather be the guy burning cheap carbon, or the guy footing the bill?

Luckily we still live in organized societies where destructive behaviour eventually gets shunned, and there is a (survival) incentive for everyone to foot the bill.

We have excess energy all the time. Many power plants have fixed, unpredictable (e.g. solar/wind), or slow-changing output. When demand is low, these plants often are often producing excess power.

An even more egregious example is gas flaring. The extraction rate is not totally controllable, so there can be more pressure than the plant can handle. Currently, most plants just burn this gas without generating anything, because it would be prohibitively costly (compared to the return) to transport that electricity.

As appealing as that narrative is (just utilize waste electricity, its cheap/free!) a plant (making anything, not just this chemistry) that only runs 50% of the time for e.g. nighttime electricity costs twice as much[0] as one that runs all the time.

To the parent re: efficiency and economics, the supplemental info: https://pubs.acs.org/doi/10.1021/jacs.9b07310 (as a rule, free/open access w/ 90% of the utility of a given paper) has the half cell potential at about 0.6V[1] vs RHE, which puts a whole cell potential at about 2V. So count the electrons to convert CO2 to propanol, take Coulomb's constant to get amps, convert to watts, and do the stoichiometry to get kwh/tonne propanol.

This is all ignoring throughput and CAPEX utilization, which is almost certainly poor (but not unexpected at this stage of research).

It is also worth noting that they are using a 3 dimensional, convoluted electrode (carbon cloth) to support their catalyst which may be responsible for the claimed 'trapping of CO'-effect, rather than their specific catalyst. Notably C3's have been observed before in CO2 reduction from less involved catalysts.

tl;dr Probably not very efficient at all, I'm too lazy to do the math. If it was efficient, it would probably still be wildly uneconomic to make propanol via this route.

[0]per unit of production, revenue

[1]Don't forget to account for side product production, per the supplemental information they are making about 600 moles of H2 per mole of propanol (hard to read the chart).

The fact of that matter is that this is something we have to do, both to undo the effects of climate change, and to ensure energy deposits for posterity in case we fuck it all up.

It's non-negotiable. We have to do it. So the economics of it don't matter. We aren't wasting power. We're paying back a very large debt to the planet that we've been accruing for over a century.

>economics of it don't matter

Yes they do and saying they don't only hurts efforts with actual chances to succeed. Money isn't some made up thing, it is man-hours and resources, and spending people on feel-good technology keeps them from doing actual good to help the environment.

No, they don't. This isn't "feel-good technology". We're talking about saving the ecosystem and providing for posterity.

There are no ifs, ands or buts about it, we have to return the energy we borrowed and rebind the carbon in our atmosphere. It doesn't matter if thereisnospork doesn't see the utility in this, it doesn't change reality. So again, the energy is not being wasted. It's being used. Just because there isn't a net 0 expenditure doesn't mean it's a stupid idea, that sounds like a Conservative talking point waiting to happen.

No, we are talking about effective ways to save the ecosystem, and this technology is effective in the same way a unicycle is. It works, but only an idiot would propose investing in unicycles over bicycles or scooters or electric cars (etc.) to green up urban transit. Don't be that idiot.

So energy is only meant to be used for powering our frivolous lifestyles but we aren't allowed to store it for later use while simultaneously fixing our atmosphere? Lol okay.

Gas flaring really needs to be brought under control. As does direct methane leakage. Both of those are tremendous contributors to greenhouse cases from pure waste.

I'm starting to think that the solution might be a "drilling/price moratorium" rather than a direct carbon price. Like OPEC but global.

That's wasted energy, not excess energy. If we're going to invest any resources into doing something productive with it, it will be towards doing something profitable. Who's going to invest a ton of money into infrastructure that doesn't pay anything back?

And I don't see how gas flaring has bearing here. If it's not profitable to capture carbon fuel that's right there, in the form a widely traded energy source - why on earth would it be profitable to burn it, to power a generator, to extract CO2 from the air, to turn it back into carbon fuel? You just end up back where you started. Surely it's easier to simply build a plant that can handle higher pressure surges, and ship the gas as-is. But it's not profitable.

We have excess power in many places almost every day with wind and solar. Often the utilities get charged whether they use it or not. Sometimes they even get charged on top of their regular rate for not using it. The more solutions that use this surplus power, the more the utility can cost-effectively integrate renewables into the grid.

I bet if there's not a yeast or other fungus for making that conversion now, there will be sooner or later

If we're going to start using power to create liquids to burn again ("power-to-X-to-power") why not make those liquids carbon-free?

Hydrogen is one option. Ammonia is another. Both can be burnt in engines, and have zero CO2 emissions.

It is carbon neutral to make hydrocarbons and then burn then as long as the energy source for making them is carbon neutral. The hydrocarbons have the advantage of far higher energy density, which makes them much better as fuels.

More energy efficient maybe. But I'd much prefer a city where every of the (hopefully few) car/scooter engines is either electric, or the exhaust spews water vapor.

Plugin hybrids would solve a lot of this problem. Battery can be ten times smaller and no range anxiety for much of the same benefits as fully electric

Hydrogen has huge practical problems with storage. Ammonia is an interesting idea, but direct combustion isn't practical due to NOx emissions and low temperature, and ammonia fuel cells are still at the lab prototype stage. The toxicity of ammonia is also an issue.

I recently watched a TED talk which changed my opinion of renewables from "maybe" to "no". Basically he argues that solar and wind are low density energy sources that require significant resources to capture, which all become waste after 25 years. Meanwhile we have nuclear which provides consistent base load, and for very good reasons we have gotten good at containing all the waste/pollution produced.

I'm now of the opinion we should be on a sprint towards fusion, investing heavily in other nuclear technologies, e.g. thorium, along the way.

Sorry to leave a video link, but it's what changed my mind and therefore in my opinion the best delivery of the argument I'm aware of.

https://youtu.be/N-yALPEpV4w

Save yourselves a click, it's Michael Shellenberger's talk.

A man with a serious axe to grind on nuclear, and so creative on facts with respect to renewables that he's either being disingenuous or is simply incompetent. His Bloomberg pieces are equally shoddy.

Did you mean serious axe to grind on renewables? As he hates renewables it seems.

> so creative on facts with respect to renewables that he's either being disingenuous or is simply incompetent

I work in an energy company making renewable forecasts amongst other things and I agree with your judgement.

Oops, yes I did.

He either hates renewables, or badly wants nuclear.

Too late. Absolutely none of that will be online by 2030.

The question of renewables recycling will become important, but it's hard to argue that the minerals required are both in short supply from mining and too expensive to recycle.

Edit; it looks like WEEE is having the intended result, there's already a solar panel recycling plant in Europe: https://www.livingcircular.veolia.com/en/industry/first-recy...

(I would expect there to be a small waste stream from installations due to panels damaged in handling, before the big waste stream begins in 10-20 years as the first installations start having degraded production and get upgraded)

>consistent base load

The amount of nonsense I see pumped out by energy "experts" is insane.

"Baseload generation" is a fallacy. There is nothing saying you need the amount of power below which demand never drops to be met with thermal plants.

Grid frequency stability is a challenge facing grids transitioning to renewables - thermal plants like coal and nuclear have a lot of inertia in their rotors and so slow the rate of change of frequency. However, there are other technologies and techniques for stabilizing grid frequency.

In the UK it is becoming the case that wind is the "baseload" as in they undercut everyone on the market and so are always first.

Nuclear is almost uninvestable, investors often require government backed minimum energy price guarantees and building of nuclear plants takes far too long. The government often has to pay for much of the cost of the plant anyway.

A nuclear fission grid is not going to happen. It is not the way to go.

What can be done is strategic over-provisioning and positioning of wind power (for the UK). Wind power almost always produces something, this can be statistically modeled. The need for utility scale grid storage is overblown.

Meanwhile, Hinkley Point C is £3bn over budget and the Flamanville nuclear power plant, containing the same reactor design, is EUR 8 billion over budget and more than a decade behind schedule.

The UK has 6 (soon to be 8) of the 10 largest offshore windfarms in the world.

Desert solar is extremely predictable. On the rare cloudy desert day, which you can predict half a week in advance, you increase prices statically or dynamically (for e.g. 15min intervals) to force preemptive load-shedding.

This requires enough solar to break even over 24h in the winter, and enough storage to cover the night.

You need large HVDC lines, however.

This might be a nice usage of surplus renewable power. Just use it to unburn CO2.

You don't get "free energy" by using a catalyst, but you do get it "cheaper" because usually you need much more than the reaction energy to break the bond.

Or, putting it in monetary terms, the "price" is the same but the fees are cheaper.

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