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A Quest to Make Gasoline Out of Thin Air: Prometheus (YC W19) (bloomberg.com)
190 points by swibbler 79 days ago | hide | past | web | favorite | 279 comments

This is really, fundamentally important technology. Emissions reduction will not work: https://www.scientificamerican.com/article/nations-are-not-r...

> The authors of the report stated in a press release that the kind of drastic, large-scale action the planet desperately needs has yet to be seen, even though global emissions have reached record levels at 53.5 billion metric tons in 2017, with no signs of peaking.

> Cities, states, the private sector and other nonfederal entities may be best placed to take bold actions on climate change. According to the report, the globe may need to reduce carbon dioxide emissions by 19 billion metric tons by 2030 to close the 2 C gap.

That's a 35% reduction in global CO2 emissions over the next decade. It's not going to happen. CO2 emissions are growing like this: http://folk.uio.no/roberan/img/GCB2018/PNG/s11_2018_Projecti.... The U.S. and EU could go back to 1960 levels of emissions and it would cut only about 3 gigatons. China alone increased its usage 3 gigatons in the last 10 years. The rest of the world increased its emissions by that much in the last 15. Bringing Indian emissions up to Chinese per-capita levels would add 7.5 gigatons.

A 30% reduction is taking the world back to 1990. The U.S. has added maybe half a gigaton since 1990, and the EU actually dropped about a gigaton since then. (The difference is largely due to the fact that the EU28 countries grew only 8.5% since 1990, while the US grew 30%.) But the rest of the world has added 15 gigatons since 1990. That 15 gigatons represents a shift from desperate poverty in Africa, India, and China to lower income status (though still many gigatons away from the standard of living enjoyed in the US and EU). That cannot be undone.

The only serious solution to climate change is carbon recapture.

It has to be both. If we want to have any hope, we have to dramatically cut emissions AND we also have to invent magic new carbon-scrubbing technology and deploy it at a global scale in the next 30 years or so.


> As you can see, in either scenario, global emissions must peak and begin declining immediately. For a medium chance to avoid 1.5 degrees, the world has to zero out net carbon emissions by 2050 or so — for a good chance of avoiding 2 degrees, by around 2065.

> After that, emissions have to go negative. Humanity has to start burying a lot more carbon than it throws up into the atmosphere. There are several ways to sequester greenhouse gases, from reforestation to soil enrichment to cow backpacks, but the backbone of the envisioned negative emissions is BECCS, or bioenergy with carbon capture and sequestration.

> BECCS — raising, harvesting, and burning biomass for energy, while capturing and burying the carbon emissions — is unproven at scale. Thus far, most demonstration plants of any size attaching CCS to fossil fuel facilities have been over-budget disasters. What if we can’t rely on it? What if it never pans out?

> "If we want to avoid depending on unproven technology becoming available," the authors say, "emissions would need to be reduced even more rapidly."

> Check out that middle graphic. If we really want to avoid 1.5 degrees, and we can’t rely on large-scale carbon sequestration, then the global community has to zero out its carbon emissions by 2026.

(emphasis mine)

Note that article is three years old and carbon emissions increased significantly over that time instead of going down as in the middle graphic. (It didn't even stay constant as in the first graphic, which would push the deadline to go to zero emissions to 2021.) So in reality we probably have to go to net zero by 2020.

Here is a nice graphic of reduction curves for staying within 1.5° warming: https://mobile.twitter.com/rahmstorf/status/1070717050430070...

>> we have to dramatically cut emissions

The "we" in this is primarily China and keeping third-world countries from industrializing using the means that the Western world used to get up to speed. It is not the Western countries, as raynier pointed out. As long as we understand the magnitude - and perhaps incredible unfairness - of the problem, then that's fine.

But cutting emissions in the United States and Europe isn't going to do anything.

This is such a common misconception. US per capita emissions are around 15 tons and China is around 7 tons. And don't forget that there is a lot of creative accounting going on. All carbon emissions are "exported" by making china the factory of the world. Furthermore flying is not counted in US emissions... I don't think emissions are actually reducing in the US. And let's not forget about the shale "revolution". Oh also: the US has the highest historical emissions. There is an interesting interactive graph made by carbonbrief: https://mobile.twitter.com/carbonbrief/status/11207159885326...

>> But cutting emissions in the United States and Europe isn't going to do anything.

You're right, we shouldn't bother doing anything, we should just tell them to clean up their act.

Your children will die unless you lobby your representative to listen to this person. This shit is realer than any other crisis in the history of mankind and we face extinction if we do not fight it now. Pay attention.

I don't think inaction causing extinction is certain. All extinction scenarios involve unproven positive feedback loops like the clathrate gun hypothesis. It seems to me quite likely that billions of humans will survive in the remaining habitable regions, even if the fight for those regions turns into World War 3. Really it's not much worse than the Cold War-era nuclear war scenarios.

Oh not much worse than nuclear war. Carry on then.

They'll die even if I do, assuming you are right and you think this problem is as large as you say it is. Our representatives care little about us.

On the contrary, decarbonizing fuels before you ship them to market is a way more serious solution. E.g. we already have big plants in the petrochemical industry that go natural gas -> hydrogen and CO2 -> separate out CO2 -> geological CO2 storage.

The benefit with capture at this level is that the partial pressure of CO2 is orders of magnitude larger, so you pay a lot less (both CAPEX and OPEX) for the same amount of capture.

When we really need negative emissions, this same cycle can be achieved by starting with bio-gas (known as BECCS).

> natural gas -> hydrogen and CO2 -> separate out CO2 -> geological CO2 storage.

Everything I've seen about H2 tells me that electric cars are just better. Luckily for your theory, it's still possible to do what you want with electric cars - just carbon capture at electric power plants.

For cars, sure. But there are applications where being able to carry around buckets of energy is very helpful. It's particularly important if you need to supply power to somewhere that doesn't have power lines; carrying batteries around is likely to be difficult, and they can be easily damaged. Emergency generators in a crisis area might need to be refueled before the grid can be brought back up. Flying vehicles will probably remain fueled for a long time as well. The military is another big consumer of fuels and they strongly prefer not to be limited by availability -- world wars have been influenced by that kind of thing.

Maybe cars, but the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better.

> the weight of batteries is a problem for larger vehicles that need long range, like a bus, truck, or plane. For those hydrogen might be better.

China is already leading the world in electric busses. They work great. Busses are such good vehicles for batteries, that for some routes it may even make sense to run them with super-capacitors, with chargers embedded in the road at stops.

Trucks are always going to be a problem. This is probably the area where H2 might have the best shot. The big problem, however, is that they are a relatively small portion of vehicles. If they're the only ones running H2, it's probably not going to work.

Airplanes, for the most part, aren't going to be electric (although I've heard rumblings of short-range commuter electric aircraft being planned). I doubt they'll be hydrogen powered either. While they aren't as encumbered by the rocket equation as... rockets, they do feel pressure from additional weight. Additionally, the added volume of H2 compared to something like avgas (on a MJ normalized basis) would negatively affect the aerodynamic efficiency of airplanes. Probably going to stay with petroleum for the foreseeable future.

> Busses are such good vehicles for batteries, that for some routes it may even make sense to run them with super-capacitors, with chargers embedded in the road at stops.

I would think busses are a very poor fit for batteries: their economics favours driving around for as long as possible (switching drivers in shifts). Any time spent charging is a waste.

This is less favourable than a consumer car, which sits around unused for most of the time (hence easily charged) and usually only makes a few short trips a day (e.g. commute).

I can understand the desire for supercapacitors on busses, since they are much quicker to charge than batteries. Putting chargers in the stops is a way to mitigate the low energy density of supercapacitors: they only need to last as far as the next charging point.

I think supercapacitors + fast charging stops makes busses very suited for electricity; but I don't think they're best suited for batteries (the fact that there are battery-powered busses shows that there's enough wiggle-room in the economics that they can work despite this unsuitability).

> they only need to last as far as the next charging point.

You had better hope that your bus doesn't get stuck in traffic on the way there, then.

Why? That's part and parcel of lasting as far as the next charging point.

I didn't say "assuming no traffic" or similar, because that would be silly.

You seem to be critiquing an incredibly flimsy straw man.

For aircraft, fuel characteristics relative to airframe and payload also matters.

Liquid hydrocarbons store readily in wing tanks at temperatures from (roughly) -50C to 50C. Pasengers and cargo can be allocated to fuselage, arranged in a contiguous space for the length of the craft.

Pressurised hydrogen favours cylyndrical or spherical tanks, located near the fore-aft midpoint of the craft, effectively segmenting the (pressurised) fuselage in two; before-pressure-vessel and aft pressure-vessel . Cryogenic hydrogen would require Dewer vessels and venting with considerations for mitigating hydrogen explosion risk -- present over a wide range of concentrations.

And in both cases, metal embrittlement and molecular leakage occur.

Adding a few carbon chains mitigates all these factors.

>If they're the only ones running H2, it's probably not going to work.

Aren't they practically the only ones running diesel currently? Maybe Trains + other diesel vehicles is a surprisingly large percentage, but... I'd be surprised.

A small percentage of vehicles by sheer number perhaps, but not by miles travelled. An average truck is working 50 hr weeks, plus commute time for the driver etc. As opposed to your average car which runs twice a day for 30 mins.

Still a small percentage. While the average car is 30 minutes twice a day, the small percentage of cars that are not average are still more than the trucks. People on vacation can drive all day. The average car is used for a dentist appoint in the middle of the day once in a while - this all adds up to a lot of cars on the road.

> China is already leading the world in electric busses. They work great. Busses are such good vehicles for batteries, that for some routes it may even make sense to run them with super-capacitors, with chargers embedded in the road at stops.

Alberquerque had to return electric buses because they didn't perform up to the range requirements.

Electric bus range goes down the moment you introduce any sort of elevation, which is why Shenzhen, a relatively flat city, has them, and Hong Kong, an extremely hilly and mountainous city, considered the pilot a failure.

Shenzhen has quite severe elevation differences (which is why a lot of it is unbuilt, even though land values are extremely high) but the bus network was planned to run mostly on the flat bits. HK, being heavily built up already, does not have the luxury of being able to do such planning.

I think that's backwards. Size and weight of batteries is more of a problem at smaller scales - electric motorcycles get up to around 220 miles (Zero SR) compared with electric cars at 370 miles (Tesla Model S). The Tesla Semi has an advertised range of up to 500 miles.

What's the recharge time for that motorcycle?

They're a little cagey about that (https://www.zeromotorcycles.com/charging/) but it looks like it can fast charge in ~1hr and charge off a standard wall outlet "overnight".

Right. I'd think a bike would charge quickly.

Tesla S require 4h45m at 240V/90a, and 52 hours on 110v (prusumably 20a).


Both range and recover matter.

>The Tesla Semi has an advertised range of up to 500 miles.

I'll believe it when they ship it.

Some buses need long range, such as that from Munich to Baku. That's not the common case: the common case is more like line 59 in Munich, whose route is about 14km long. A lot more people take the 59 to work than take the bus towards Baku.

Trucks: There are different kinds, but you can separate them into "ones that could be replaced by trains" and "ones that don't really need long range" and not be very wrong. There are exceptions, such as sparsely populated areas, but they're tautologically minor.

Planes: Need dense energy, sure.

Presumably the bus running on line 59 doesn't run once a day; it makes lots of loops back and forth on line 59. Electric charging is not so fast that you can do it in the short amount of time that buses are required to turn around, which is usually measured in minutes.

A rail network rarely has capacity for both decent freight (America) and decent passenger service (Europe). There are some exceptions to this rule, like China. But on their end that necessitated building an entirely new national rail network so that they could make room for freight trains on the old one.

Are you saying that the 59 can't be electric because then it would have to wait empty at its two destinations for twenty minutes instead of ten before starting its next route, and that's impossible?

Nothing is impossible, but it's certainly more difficult.

If charging time is twenty minutes and the bus needs to be out in ten, you need two additional buses on standby to maintain the current schedule (one for each direction.) Except you need more than two, because transit agencies keep a "spare factor" of buses in case a bus breaks down or is otherwise unexpectedly available, and so you probably need ~2.2 buses for this single route.

Scale this up across an entire bus network and that could easily be a hundred or two additional buses. And when you're talking about increasing the fleet by that much, you need to consider storage space for said buses. It's incredibly hard to site bus depots, because you want to minimize the distance from the depot to the start of the line, but you also have to consider the price of land and whether or not a land parcel's best use is a parking lot for buses. And this is before you consider that very few people want a parking lot they can't use as a neighbor.

And so what seems to be a small problem can very quickly snowball into a large one. Public transit agencies aren't exactly flush with cash to buy a larger fleet than otherwise necessary, or land to store said larger fleet. And even if they had this money, is it best spent going electric? Money that is spent going electric is money not being used to keep the fare down or boost services.

There's a big difference between US, Canada or Australia, and say Europe regarding this. In Europe the majority of buses and trucks don't need to travel long distances. And as the population in Europe is generally much more dense soon there will be a local infrastructure of recharging stations available everywhere, so even those that need to cross long distances won't have a big problem recharging more often. The regulations in EU are really strict on bus and truck drivers, so they have to make a lot of stops and take regular breaks anyway (every 4.5 hours IIRC)

Buses travel long distances because they run the same route throughout the day, and the turnaround time of a bus is expected to be minimal.

Alberquerque, New Mexico had the not unreasonable requirement that a bus should have a range of 442 km, but the buses that were delivered could not reliably meet that goal on a route that has some elevation gain and in a hot climate. https://www.abqjournal.com/1246094/abq-rejecting-all-byd-art...

Trams, trains, high speed rail.

There's some bus lines with overhead lines as well. The problem is of course infrastructural, and you still need truck for the last X miles.

Which is where Tesla and that other electric truck company come in, of course.

Call me when we have transpacific or transatlantic high speed rail, or when we have a route linking Europe to Asia or Africa that doesn't take the better part of two days.

Call me when transpacific or transatlantic air travel is carbon neutral.

This is a very good point. Carbon capture at places like factories in plants is nearing viability. If we can burn oil, gas etc. and effectively capture CO2 ... well that's a much bigger win. Trying to capture/store from combustion engines in cars for example is a non-starter. And we have a lot of Oil and Coal, and it's energy dense ...

This article has nothing to do with carbon recapture. The gasoline produced from carbon is then intended for burn...

This is simply an alternative electricity/power storage mechanism. But great to reduce emissions but is not intended for negative emissions (for which there is other tech)


Also, the only real solution for stopping warming is geo-engineering. We'll not have enough clean energy to even think about effective (as in - actually making an impact) carbon recapture.


> The gasoline produced from carbon is then intended for burn...

If it's captured from the atmosphere and then burnt then surely it's zero-sum (apart from the energy cost of capture). Is this not better than releasing historically captured fossil fuels with a larger net increase in atmospheric levels?

If the capturing process is net-negative in terms of CO2 emmissions then perhaps we could invest in capturing more than we require for fuel - ie pull the CO2 out of the atmosphere and stockpile it in non-gaseous form. My experience is that people are willing to pay to clear their conscience and feel that they're making a positive climate change impact, but irrationally very resistant to changing their own behaviour.

Plenty of projects for harvesting CO2 getting prototyped -- and my point is the OP is not one of them. If the purpose is just storage and not making fuel, there are other ways (like liquid CO2).

That's all true, but it depends completely on the cost. Fuel is a fungible good: one barrel of, say diesel, is equivalent to any other (assuming they're the same "grade", etc.).

Stockpiling a barrel of fuel pulled from the air is the same as stockpiling a barrel of fuel dug out of the ground (assuming it would otherwise have been burned): both result in 1 barrel-of-fuel-worth of CO2 in a stockpile rather than the atmosphere.

It takes a lot of energy to extract fuel out of the air, so buying a barrel of fuel-from-the-ground is currently cheaper. Hence we can stockpile more of it for the same cost, and have a bigger effect on the climate.

We can go even further: fuel-from-the-ground was already stockpiled, as fuel-in-the-ground. Locating, extracting and refining it takes a lot of energy, so buying a barrel of fuel-in-the-ground and leaving it alone is much cheaper than buying fuel-from-the-ground or fuel-from-the-air. It's also has lower maintenance costs.

Activities like carbon sequestering or extracting fuel from the atmosphere are nothing more (or less) than methods for redistributing energy and costs.

This redistribution is useful for those cases where fuel is a necessity, e.g. jumbo jets. Extracting that fuel from the atmosphere using renewable power (carbon negative) would allow jumbo jets (carbon positive) to be overall carbon neutral. From a cost and energy perspective that would be hugely inefficient compared to simply powering the planes with renewable energy directly; the only reason it should be taken seriously at all is because electric jumbos are not an option (and won't be for a long time, due to physics, battery chemistry, etc.).

In any situation where renewable is a viable option (e.g. electricity grids, cars, etc.) then these redistribution schemes make no sense. Every step in a process loses some efficiency; since the whole point is to reduce atmospheric CO2, and atmospheric CO2 depends on energy usage, introducing inefficiencies to "clear our conscience" is counter productive.

Of course there are some nuances. For example, it might make sense to have nuclear plants pulling fuel out of the air for stockpiling (nuclear works best with a steady demand). We could think of this as plundering the nuclear fuel of future generations (the energy we leave in our stockpiled fuel won't match that of the nuclear fuel used to make it, due to inefficiencies). This may be desirable, if it's cheaper to spend that fuel fixing our climate mess now, than it would be for those generations to fix it themselves if we burden them with it.

(Note that burning any of that nuclear-aquired fuel-from-the-air also makes no sense if we could have just used the nuclear power directly)

There's a pervasive solution bias in thinking about climate change and this is an example of it.

If reducing emissions won't work and we have to find a solution, then surely negative emissions is the answer?

The problem with that is that the fact that we need a solution does not mean that a solution exists and that eliminating solutions that definitely won't work doesn't mean that the remaining ones have to work.

I'm not saying carbon capture will work. I'm saying that we won't be able to address climate change if it doesn't work. "We're totally fucked" is also a possibility.

How much do today's "carbon recapture" methods need to grow? What's the timeline on them looking like?

P.S. The first Google result for carbon recapture is titled "“Direct air capture” of carbon dioxide won't solve climate change"

P.P.S From Wikipedia with a cited source:

capturing and compressing CO2 and other system costs are estimated to increase the cost per watt-hour energy produced by 21–91% for fossil fuel power plants;

Hi, Rob from Prometheus here! Most of the skepticism about CO2 removal from the air is focused on "carbon sequestration and storage" or CSS, which is mitigation of emissions from fossil fuel by putting CO2 into the ground, for example. Turning CO2 from the air into useful products like fuels and building materials is much more capable of scaling because these products have value independently from regulations or carbon taxes/credits. If you can be the low cost producer of a commodity like gasoline or polyethylene, it's possible to grow zero or negative carbon capture very quickly to very large scale. If all transportation fuels, heating fuels, and plastics were from atmospheric CO2 capture, this would be more than 10 GT of CO2 a year, which is hugely significant.

>Most of the skepticism about CO2 removal from the air is focused on "carbon sequestration and storage" or CSS, which is mitigation of emissions from fossil fuel by putting CO2 into the ground

That is false! Most of the skepticism about CO2 removal from the air is focused on the difficulty of said removal, compared with the relative ease of removing CO2 from eg power plant exhaust.

> Turning CO2 from the air into useful products like fuels and building materials

You mean something like DME synthesis from CO2 and H2? Isn't atmospheric CO2 capture sort of expensive at 400 ppm? Obe would obtain one kilogram of CO2 from 2500 kgs of air.

Turning atmospheric carbon to building materials is already being done with plant based fiber mixtures such as hempcrete or fiber cement.

Hi Rob! Is it possible to produce gasoline through atmospheric CO2 capture for less than traditional methods? Will CO2 capture be competitive in real costs?

I cannot see how you could take CO2 and make gasoline out of it using less energy than what the gasoline contains. At best, you will need to supply that energy via something like solar panels. Then it becomes a question of efficiency: how many Watts of gasoline can you produce per Watt of electricity you have? My guess is, not many.

It can still be competitive with things like tar-sand extraction, which takes more energy than you get out of the oil. It's only economically viable because energy in gasoline/oil form is more valuable than the energy content itself, due to it's ease of transfer. Air sequestration might be a viable fuel source in regions where import costs of fuel are high, but energy is cheap.

I did not know that! Thanks.

I am less concerned about economic efficiency and more about environmental efficiency. The process to set up carbon sequestration facilities will itself produce CO2. If you produce a paltry amount of gasoline because all your energy is going towards that conversion, it might take you years or decades to actually reduce atmospheric CO2.

Even more important is the fact that the gas you produce and sell will go right back into the air as CO2, further reducing your net impact. You would basically need to produce gasoline faster than people can use it. Do you think a private company can do this process and outpace the consumption of Asia and Africa? It’s a catch 22: either your process is so inefficient that you pollute more than you clean up, or it’s efficient enough that you just drop the prices of gasoline, putting CO2 right back into the air. Their option is that you produce so much gasoline that you cannot sell it fast enough. Ironically that will tank your profits.

I think doing something other than gasoline is the answer. Make fertilizer: it will help grow the ecosystem while not immediately winding up as CO2.

This is false, the net energy is positive for tar sands it is just less than for conventional oil extraction.

The ideal method would be CRISPRing up some algae to synthesize gasoline, but we're pretty far from that.

you cannot. That would be a perpetuum mobile

very exciting! Do we know yet if gasoline is the most efficient hydrocarbon to make from CO2 for a given amount of electricity? I would think there are a whole range of oil like things that could be produced. I always dreamed about using nuclear power to do all kinds of terraforming type things that would otherwise be energy inefficient.

It’s not thermodynamically possible to recapture carbon from the air without using more energy than was obtained by burning it the first place.

Thermodynamically, no. But is that the question?

We're a long way away from consuming so much energy we thermodynamically scorch the Earth, right?

It seems like they want to know if you can be mostly carbon neutral and generate existing fuels.

If that's the case, then if you have access to a cheap form of renewable energy -- huge amounts of geothermal, tidal, or solar -- you could generate a ton of something-like-gasoline, reduce carbon, and come out nearly neutral when re-burning it.

Theoretically, you can profit if the renewable source of energy is cheaper than the cost of generating and distributing the fuels.

I'm skeptical this is possible. But if it is, I'm optimistic it will actually happen.

It is the question. You need to break up the CO2 molecule and reconstitute it as gasoline. That will take more energy than the gasoline had initially. So you have a process where you take say solar energy and convert it into gasoline chemical bonds. Great, what is your efficiency of this process? Because if it is close to 100%, great. But chances are it is much closer to 0, at which point you’d be better off just using that electricity for something else.

True, many people don't realize this. But carbon capture solutions don't necessarily need to be efficient - we are not doing it to make more energy, we are doing it to clean up the many decades of mess we already made in the atmosphere. So yes, we will have to spend energy, to clean that up, naturally. The most important part is that none of these solutions is exclusive and shouldn't be pictured as exclusive. We need to offset fossil fuels, lower our energy use, and suck CO2 from the atmosphere. All three of them.

>But chances are it is much closer to 0, at which point you’d be better off just using that electricity for something else.

Unless your ultimate goal is not just to use energy efficiently, but to recapture carbon dioxide.

Solar panels take energy to produce, transport, and install. Mining the lithium needed to produce them is pretty harmful to the environment. Other parts of the process are pretty bad too. If your efficiency is too low, if you install a gigawatt power plant and produce a half gallon of gasoline a month, you will take way too long to get an emissions ROI. Just recapturing CO2 requires less energy than recapturing and reconstituting it as gasoline. Sure you can sell the gasoline and maybe make some $$ but will that actually in the end be a net negative for the atmospheric CO2? The answer will 100% depend on efficiency.

As an aside, we're not that far from boiling the oceans at the current rate of growth in energy usage. Maybe 400 years, IIRC.

Hydrocarbons are better energy stores than batteries. If we can “charge your car” by pumping hydrocarbons into it, that is better than lugging around heavy batteries (maybe.) so, in a way, co2 -> gasoline via solar power (or nuke) is an overall win.

I personally doubt the energy cost for the conversion is so low that it makes sense, but would like to see that demonstrated. Then you are still burning hydrocarbons, which is a big health problem.

I imagine the goal is to use renewables for the energy required for capture.

The esoteric read on this, then, is it is a bet on fusion.

And before that?

The author of the article (who does not appear to be an expert in anything) overlooks that renewables only address part of the emissions picture. Even if the U.S. switched tomorrow to 100% renewables and 100% electric vehicles (including trains, cars, planes, and ships), and you ignore the CO2 emissions of making all those new power plants and vehicles, U.S. usage would only go down by 3.5 gigaton: https://www.epa.gov/climate-indicators/climate-change-indica.... It won't change the CO2 emissions created by home and commercial heating, agriculture, and industrial uses, which add up to another 3.5 or so gigatons.

And even the U.S. and EU going to 0 carbon emissions wouldn't offset the growth in India, China, and Africa. And those places are a long ways away from electric cars and solar power plants. (Also, where would you put them in say India or Bangladesh?) Carbon recapture can do a very important thing renweables cannot--allow the developed world to suck out the developing world's CO2.

The current cost of carbon capture is about $120 per ton. If it follows the same trend as improvements on solar panel cost, that could be $40 per ton in a decade. At that price it would cost $300 billion annually to remove the extra carbon India will be adding to the atmosphere by then. That will be just 5% of India’s GDP by then.

>And those places are a long ways away from electric cars and solar power plants. (Also, where would you put them in say India or Bangladesh?)

Huh? What does that mean? You mean there is so space in India or Bangladesh to put solar power plants?

>It won't change the CO2 emissions created by home and commercial heating, agriculture, and industrial uses, which add up to another 3.5 or so gigatons.

So address each one in turn, or in parallel. You give no reason not to.

Lot of people use the 'golden hammer or nothing argument'

Meaning if a proposed solution is partial then we shouldn't do anything. It flies in the face of the reality that most solutions to complex problems involve chipping away at them.

Currently there is a host of technologies which emit to much CO2. Personal transportation is just one of them.

> The current cost of carbon capture is about $120 per ton. If it follows the same trend as improvements on solar panel cost, that could be $40 per ton in a decade.

This sounds reasonable to me. Do you believe this will be the way forward most likely?

We can only hope. It's super early in the development of carbon capture, so hopefully there's still a couple 50% cost reductions ahead

>The current cost of carbon capture is about $120 per ton

I don't know where you got this from (citation?), but I am sure this is not the cost of capturing CO2 from the atmosphere via "technology" (trees - arguably yes).

Carbon Engineering claims it will be between US$94 and $232.


I have reviewed the original paper which from which the "$94-$232" estimate is obtained. You can find it here: https://www.cell.com/joule/fulltext/S2542-4351(18)30225-3

My comments are as follows:

1. Obviously, this is not the current cost, but an estimate for a hypothetical future plant.

2. You can get wildly differing estimates through a series of small discrepancies in the assumptions. Comparing the provided estimate (Table 2 in above link) to the estimates for other CO2 capture projects the following things stand out immediately: a) 7.5% CRF calculation should be ignored as unrealistic, 12.5% CRF is okay; b) O&M costs are low, for complex plant with caustic chemicals and high temperatures a fair assumption may be 6% of CAPEX per year rather than approx 3% c) 20% contingencies at the conceptual stage are too low, 40% would be perhaps defensible. Also, I don't see a basis for including Row D in the table, the commercial assumption is not justified.

Considering the above, if all goes well, plant number 100 might be able to capture CO2 for $200-300/tonne, better than the current claimed $600/tonne for a plant actually in operation, but nowhere near as good as other options.

Don't forget that there are also low temperature DAC routes that can use waste heat (climeworks, global thermostat, antecy, skytree). If you get the heat for free you only need energy for your fans. This drastically reduces the price. There are some good papers that do proper cost analysis on DAC. 100$ or lower is within range in a decade. I'm not in front of my computer now but if your interested I'll send the papers

That would be great, my "anon" email is in my profile.

You should read about process heat from nuclear. There's several companies aiming to do this: https://usnc.com/MMR.html

How do you switch to 100% renewables and then still have CO2 emissions from heating?

Is the first statement just about transport?

A plurality of home and commercial heating in the US involves direct burning of fossil fuels. So even if the grid is 100% renewables, you’re talking about spending thousands of dollars per house to replace oil and gas furnaces with heat pumps.

Okay, so 100% renewable grid.

A rapid transition would be hellishly expensive, but new installations can certainly be looking at heat pumps.

I wonder if there is a way to structure penalties/incentives so that home builders and landlords end up installing systems with lower lifetime costs (and lower environmental impact), rather than whatever is cheapest upfront.

>wouldn't offset the growth in India, China, and Africa. And those places are a long ways away from electric cars

On the contrary, China is going crazy for electric cars. And the U.S. and EU are starting to turn as well. I wonder where you are getting your ideas.

China put 28 million cars on the road in 2018. 95% were ICE. China put over 1 million heavy trucks on the road in 2018. Almost all were ICE. By 2025, the government aims to get it down to 80% ICE. That’s at least another 100 million new ICE vehicles on the road in the next half decade, plus the 300 million existing vehicles (which in developing nations are retired very slowly). Compared to maybe 20 million EVs if the government meets its target. China is currently building new coal fired capacity equal to the total amount of US coal generation capacity—and many times the renewables capacity it has added in the last year. Power plants are long term investments. These plants will be in service for decades to come.

Again, we need to cut 19 gigatons in the next decade. If “going crazy for electric cars” means that 80% of new cars—forget existing cars, and new trucks, etc.—will still be ICE half a decade from now, emissions reduction is not going to work.

> Carbon recapture can do a very important thing renweables cannot--allow the developed world to suck out the developing world's CO2.

What would that look like? Pipes on top of smoke stacks in China? Big mesh blanket clouds in the sky?


There is a lot of work. I'm not an expert, but it seems like our early attempts are orders of magnitude off in terms of efficiency, but there have been some breakthroughs using nano-tech to create custom structures that are much more efficient, but i'm sure it needs a lot more research and money to become commercially viable.

Realistically, "carbon recapture" barely exists today. It's a science experiment / excuse to avoid reducing emissions.

I have to wonder how much of the innovation here will couple advancements in catalytic conversion with accepted inefficiencies in "storing" renewable energy by sourcing from the atmosphere.

Because that's essentially what these initiatives are doing. They're seeking to artificially tighten the carbon cycle so that we can maintain the status quo indefinitely.

> so that we can maintain the status quo indefinitely.

Is that good enough? I've read that in China, they have some days where there are warnings to stay inside because there are random green substances in the air?

How does the technology from Prometheus count as carbon recapture? We end up taking a (relative to the size of the problem) small amount of the 'extra' carbon out of the atmosphere... and then proceed to burn it and put it right back in. IMO carbon recapture only counts if the carbon gets removed permanently. But Prometheus's technology is problematic for other reasons.

Let's say that all of the $3/gallon which was quoted can be attributed to electricity cost and nothing else. At $0.12/kWh that would be turning 25kWh of electrical energy into ~36kWh of chemical energy (gasoline). Now it needs to be transported to the gas station, which costs something like 10% of the total energy content. So now we're back to ~32kWh of chemical energy delivered to the customer. They convert it into mechanical energy at 20% efficiency [1]. So you've converted 25kWh of electrical energy into 6.5kWh of mechanical energy at the customer's wheels. Meanwhile, we would be using a fuel that is interchangeable with carbon we dig out of the ground. What are the chances we limit ourselves to only the "green gasoline" and ignore the stuff in the ground?

Meanwhile electric vehicles convert ~60% [1] of the electrical energy used to charge them into mechanical energy. So you convert that 25kWh into 15kWh of mechanical energy. Energy can be generated in many ways, many of them not very green at all. Let's assume both the "green gasoline machine" and the EV charging box are powered by the same grid. You could go 2.3x as far with the EV for the same energy input.

Now if Prometheus is making "green jet fuel" I'd be interested because there isn't any obvious electrification solution to long distance air travel that seems close to commercialization.

[1] https://www.fueleconomy.gov/feg/evtech.shtml

It's still a band-aid solution. Should pursue - but don't have high expectations. It wouldn't address the other pollutants due to fossil fuels. It doesn't address methane (which are a quarter of GHG). If it makes energy more expensive there will be massive resistance and aligning governments worldwide will be intractable. You're not going to convince developing countries to increase their cost of energy.

Root cause solutions will have to be part of the mix.

> The only serious solution to climate change is carbon recapture.

To me it always comes back to the numbers: sifting 400 parts out of a million of anything is intrinsically a pain in the ass. There's no way this is ever going to scale.

+100000 I couldn't agree more. I saw some real interesting research a few years ago about artificial leaves. I really wish one of these billionaires would stop building giant rockets and solve carbon recapture first. Apparently, our government isn't interested in it.

You mean like Bill Gates, who is spending billions on this? Or Jeff Bezos?


You mean like the guy who started an electric car company and is responsible for pushing the mass adoption of electric cars forward by at least a decade?

Fully agree. This company is located near me and does this now: https://carbonengineering.com/

I’m not sure about the specifics of this new Prometheus startup or if their process is different.

"The only serious solution to climate change is carbon recapture."

Emphatic agreement.

We must capture and sequester faster than all sources of atmospheric CO2 & CH4. By every means available. To hopefully stop and then reverse the warming.

For the viewing audience, anthropogenic carbon is now but a fraction of the problem. Tundra is thawing, forests are burning, oceans are acidifying. In an accelerating positive feedback loop. All human activity could stop today and the increase would continue.


All the nitpicking and concern trolling and harumping doubting thomases in the replies is very discouraging.

Nukes vs point source capture vs BEVs vs blah blah blah. Yes, yes, yes. It's all needed. Like thirty years ago. Stop fussing and get on board.

How are geeks not grokking the scale of the immediate threat? Arguing about rearranging the deck chairs as the Titanic is sinking.

It’s not thermodynamically possible to recapture carbon from the air without using more energy than was obtained by burning it in the first place.

Almost literally every bit of energy that we have on Earth comes from our Sun in one form or another. Obviously this method does not break that law. It uses power from the sun to do some chemistry. Like everything else in most other solar systems in the universe.

>The only serious solution to climate change is carbon recapture.

No. There's a major problem with carbon recapture that will never make it feasible, namely, carbon is a tiny percentage of the atmosphere - meaning you have to pump huge amounts of atmosphere through whatever filtering system you set up to get any significant carbon out. So that's the first major unsolvable problem. The second is that you need to put energy in to convert Carbon into some sort of fuel. That's your second problem.

So this will NEVER work. It will NEVER be cost effective. You are fighting thermodynamics every step of the way and you will not win.

The only serious solution to climate change is nuclear power (because nukes are the only energy source that can totally replace carbon-based power generation) and continual improvement in energy efficiency. And if that isn't good enough, then we're done as a species.

Well no, this is really, fundamentally wrong-headed technology. We already have more than enough petroleum to catastrophically ruin our environment.

As AOC put it, climate change is our World War II. We won't solve it by sitting on our hands and being negative about the real solutions that are out there.

> But the rest of the world has added 15 gigatons since 1990. That 15 gigatons represents a shift from desperate poverty in Africa, India, and China

Citation needed. But just taking China alone, they are shifting massively away from carbon emitting technologies and into alternatives.

Carbon recapture is a nice dream. But I'm skeptical it will deliver anywhere near the level of impact needed. Much better is to stop carbon emission at its source by making more industries sustainable... case in point, transportation should transition to electric so it can draw on the ever increasing sources of sustainable energy in the grid.

It can be very useful for energy storage and keeping existing combustion plant usable. But the op does not seem to bear in mind the fact that it requires more energy input than it outputs in the form of a carbon neutral fuel, or that renewable technologies have by this date clearly demonstrated affordable solutions to carbon neutral power generation.

When I read about these schemes to produce gasoline from CO2 and water or whatever I can't help but think someone needs a couple of semesters of thermodynamics beat into them.

Nobody thinks they'll get net energy out of this. They're spending energy to make carbon-neutral liquid fuels. The energy would have to come from renewables or nuclear for this to be useful.

The energy return on energy invested is going to be abysmal.

No more than 20% if that. That translates into synth gasoline at $30/gallon

Considering electric planes aren't feasible yet, how else do you plan to decarbonize airplanes?

Short range electric planes are being manufactured presently.

This wont be able to decarbonize anything until surplus carbon free energy is generated for it use - that need not take decades with proper governmental policies, but it means this technology will not lead the way.

Replace, as far as practicable, with fast trains and maybe Hyperloops.

How do you figure?

Estimate the cost of the energy inputs per gallon of gasoline. Account for the inefficiency and you get $15-20/gal.

>> But just taking China alone, they are shifting massively away from carbon emitting technologies and into alternatives.

The data in the OP does not support this.

Soooooo many questions.

Gasoline is a distillate made up of several hydrocarbons -- is he synthesizing all of them, or just octane? What about additives, like anti-knock agents? Plans for diesel?

No amount of fancy CNTs gets around thermodynamics. CO2 and H20 are far more stable, thermodynamically, than octane, it's partially why octane is a good fuel. Where does the extra energy come from? What is the efficiency of the conversion? What kind of thoroughput are we talking about?

How scalable - is the CNT manufacturing mature enough to support large scale rollout?

Who is on his team? Research chemists, or experienced chem Es, both hopefully?

I'm sure he knows these answers (man has a PhD is chem), would have loved to sit through that pitch.

The Bloomberg piece is very light on details; the secrecy is frustrating but understandable.

Hi, this is Rob, founder of Prometheus. The conversion of CO2 and water to gasoline is not a super efficient process, likely 50-60% at best in the near term, but that's ok, if the electricity is from a zero carbon source like solar or wind, and the cost of the electricity is low (which these days it is).

The CNT membranes are being made at full commercial scale now by my previous startup, Mattershift. Ready to go!

We've got scientists and engineers from national labs and previous efforts like Project Foghorn at Google. Hope to share some new hires soon.

There was a podcast that was associated with the article, that runs 21 minutes and goes into more details: https://megaphone.link/BLM3585271197

Hey, thanks, and best of luck, what a cool company.

It seems like you're on the cusp of breaking even from yongjik's back of the envelope math, at least for the US commercial market. Is this a refinement of Fischer-Tropsch?

However, I think you're barking up the wrong tree. The US military pays $hundreds of dollars to get fuel into a warzone. If you can make diesel (which I think you can), you don't have to go after a $3 a gallon target, you go after a $300 target. You can perfect it on sweet sweet DARPA money at a price point that will make you rich and save the military a shitload of money.

That sounds like a particularly interesting answer, but I wonder what the power and factory requirements would be to have something like this at a FOB or base?

Surely most operating bases use gas powered generators to run and not solar right?

This is genius. Also, the US military can expand everywhere and force everyone to use only the new climate friendly american fuel (TM) for affordable price.

>Where does the extra energy come from?

It doesn't particularly matter. Centralized clean energy production is often significantly easier to solve than figuring out clean alternatives to gasoline use. Especially when the problem with clean alternatives to gasoline is political - it's hard for the US to ban ICE engines in China, but it's significantly easier to sell them carbon-neutral gasoline.

>What is the efficiency of the conversion?

Generally speaking it's pretty atrocious. I don't remember exact numbers the last time I looked into things, but the sense I got is that it's roughly an order of magnitude away from economic viability at current prices.

Also, a significant switch to carbon-neutral fuel would be a significant bump up in electricity and energy consumption. So it's not a cure-all, we'd still need a massive investment in low-carbon energy production.

> It doesn't particularly matter. Centralized clean energy production is often significantly easier to solve than figuring out clean alternatives to gasoline use. Especially when the problem with clean alternatives to gasoline is political - it's hard for the US to ban ICE engines in China, but it's significantly easier to sell them carbon-neutral gasoline.

Oh! Is THIS why we're going about this roundabout process? I couldn't understand why we'd want to spend a lot of effort and energy to inefficiently produce fuel, when we could just produce electricity directly.

Honestly, this comment section is the first place where I've seen this kind of thing discussed logically online.

Using hydrogen fuel cells as an example, everywhere else either 1. Misunderstands thermodynamics, and acts like e.g. producing hydrogen and oxygen from water would somehow result in free energy, or 2. Understands it's energy-negative, but don't explain what the actual benefits would be of storing and using the energy in that manner as opposed to any of the alternatives.

Your car doesn't need a mix of lots of hydrocarbons, it would run fine on pure hexane.

Gasoline is a mix because it's made from natural crude which is also a mix... and there's not a strong reason to purify it further.

I imagine the engine is optimized to run on "average" gasoline for a given octane level, tuning compression ratio, spark timing, air mixture, etc.

I'm not an ICE engineer, so I would love to know how much of a performance change can be expected from this guy's machine.

You might find this youtube channel interesting: https://www.youtube.com/channel/UC2rzsm1Qi6N1X-wuOg_p0Ng/vid...

He has run a gasoline engine on a whole slew of fuels, including some that may be surprising, such as isopropyl alcohol, various solvents, crude oil, and a 50% diesel gas mix.

Gasoline engines can also run on pure propane, but the fuel pump, tank, and some other parts do need to be replaced.

I guess the point is that gasoline engines are not in general super sensitive, while they still could be more optimized for certain fuels.

Thats a low compression mower engine. Modern automobile engines are indeed quite sensitive to predetonation from slower ignition times offered by most alternatives without being designed for them.

>Modern automobile engines are indeed quite sensitive to predetonation from slower ignition times offered by most alternatives without being designed for them.

If by "design" you mean a different cam profile to drop the dynamic compression ratio then sure.

Maybe this can be handled by adjusting valve timing in software.

I believe the tuning is controlled electronically through software (this is what enabled VW Dieselgate). So a software update could enable the vast majority of cars to be able to use this fuel.

One thing not considered much on a balance sheet basis, there are a number of different costs. Capital, maintenance, energy, insurance, and taxes/fines/fees.

Battery electric cars exceed or will eventually exceed gasoline/diesel powered cars on a capital, maintence, and energy cost basis.

That sets up a situation where there'll be no market for synth gasoline because the capital and maintenance costs exceeds the energy cost.

Except that will only work for gasoline cars and wont happen for the next 10-15 years. It seems like this guys bet (per the other thread) is that commercial gasoline for cars is the starting point, but they want to move into jet fuel, container ships, and making the basic gasoline/oil that goes into plastics.

Considering there is no commercially available electric passenger aircraft on the horizon (as of now) and that commercial containers are unlikely to convert that seems like a solid market to go after.

And even if you could only replace 95% of the volume of gasoline with renewable-sourced options, is it suddenly a bad idea?

I have the same questions. Honestly without answers to at least some these sorts of questions and given his setup sounds like a literal black box, it will be hard not to think "Theranos?" until there are some answers.

There's no way this is a net energy producer right? So it only makes sense if it's powered by carbon-free sources?

Basically this has two uses then:

- As a stop gap till batteries and electric vehicles take over from ICE. Although if it generates carbon-neutral jet fuel that would be very useful.

- Maybe as a carbon capture device, except that gasoline doesn't seem like a great way to store excess carbon. Although the article indicates the carbon could be converted into other materials. That part isn't very clear.

The idea that electric vehicles will completely replace ICE vehicles is a hopeful one but faces a lot of roadblocks to get to 100% (or even 80%) and may ultimately be unrealistic. As such, it is dangerous to bank utterly on that goal in efforts to curb net CO2 emissions. So this is not just a stop gap but a backup plan, and more.

Additionally, as a replacement for "drilling oil out of the ground" as the first step in everything that makes use of gasoline and similar products (so jet fuel, heating oil, diesel, gasoline, lubricants, plastics, etc.) this is a good thing, not just from an emissions standpoint but also from a pollution and environmental impact (drilling, crude oil transport, etc.) aspect.

Even more importantly, this is a way to bridge the "energy storage" gap for green energy sources like wind and solar. Base electric power generation is a very second by second thing, hydrocarbon production can easily be an "average output over a week or a month" sort of thing, which is where wind and solar do well.

Batteries have the disadvantage that they require heavy resource extraction and wear out. The advantage of hydrocarbon fuel is that it is basically instantly fillable (no charging), doesn't decrease in capacity (or minimally I suppose), and energy density.

The use here is that we could use a renewable energy source, like solar, and then use the hydrocarbon generated as an energy transfer medium rather than fuel itself. Actually, this is what we do today, since the hydrocarbon in the earth is actually just naturally captured solar energy.

> The advantage of hydrocarbon fuel is that it is basically instantly fillable (no charging), doesn't decrease in capacity (or minimally I suppose), and energy density.

That first property can be mimicked by batteries without too much trouble. Just standardize them and make them swappable at the fill-up station, like propane tanks. There are financing complications with this (who owns the batteries, etc.), but it's do-able and it's already been tested by at least one now-failed start-up.

NIO does battery swapping in China.

Correct, it collects carbon in the form of CO2 and "un-cracks" it back to hydrocarbons. Likely Fischer–Tropsch process.

Gasoline is a reasonably dense and easy to transport energy transfer material, given that we already have a vast network of devices that can use it, and a refining and distribution network.

There's no information from the article to indicate if this is actually commercially feasible though, other than nanotubes will solve everything.

After reading this article, all I can say is ... ugh. What I really wanted to know was "Where does the energy come from?", and the article didn't answer that at all.

The world doesn't really have a "carbon" problem, it has an energy problem, and right now carbon fuels are the cheapest, most abundant source of energy. Even if you somehow got carbon capture to work, you're still going to have to power it - with solar, or wind, nuclear, geothermal, whatever. At that point, then the question just becomes whether using the storage medium of gas is better than the storage medium of something else, like batteries. But the article doesn't go into the core question of where the energy is coming from to turn CO2 into gas.

I would bet photovoltaic. Lowest cost per watt, the process can likely be designed to tolerate day/night variations, and the plant can be located where the sun shines.

Or nuclear. A big nuclear plant could be built somewhere with cheap land, no earthquakes, and minimal weather. You don’t even need electric transmission infrastructure.

If the capital costs are low enough, cheap or free spot electricity could be used, too. California regularly has excess production.

That would be ironic.

We would gradually go from coal and (natural gas) powered electric cars, to nuclear powered ICE cars.

I think the point is that we

1. Keep making more electric cars 2. Rather than throwing away ICE cars, we give them better fuel to use.

There are also ICE farm and construction vehicles, airplanes, generators in rural areas, pumps, etc. Gasoline is an extremely convenient fuel.


> The world doesn't really have a "carbon" problem, it has an energy problem

This is a very narrow-minded mistaken viewpoint. The world does have a serious problem with CO2 building up in the atmosphere. It also has energy need to sustain the current living standard and pace of development, but this is not a serious problem such as CO2! We could decide and enforce giving up the insane power consumption of today. But we cannot decide to pronounce the existing CO2 in the atmosphere and its destabilizing effect on climate to be a non-problem.

> carbon fuels are the cheapest, most abundant source of energy.

No, they are not. Carbohydrate fuel is the most convenient way to transport and use, but not the cheapest source of energy. The cheapest source of energy is renewables and possibly nuclear, if massive investments were made into infrastrusture and safety.

At the end of the day - does it matter where it came from?

They could be like Tesla and build a solar arm, or a wind farm, or do geothermal. You could pull it out of the grid and it'd still be better for the environment than pulling it out of the ground.

TBH saying the world doesn't have a carbon problem contradicts all of the people fighting greenhouse gas emission based climate change so I'm curious as to your logic behind that statement.

The logic is that you need to power the carbon extraction, and right now we use fossil fuels for power, so you wouldn’t be able to net reduce fossil fuels because you would be burning more than you extract.

I think it’s naive though. There is a theoretical point at which it’s economical to just build excess renewable energy production and use the extra power to repair the climate.

The logic is that you need to power the carbon extraction, and right now we use fossil fuels for power, so you wouldn’t be able to net reduce fossil fuels because you would be burning more than you extract.

Currently, we use a mix of hydrocarbon, hydroelectric, photovoltaic, wind and nuclear for power generation. Photovoltaic is quite economical for daylight and so using intermittent power for this process carbon capture process seems reasonable. Broadly, this could serve as a power sink to balance solar output, a way to use renewables for transportation and a way to suck carbon out of the atmosphere. Not all of those at once but just doing some of that seems like a win.

Sort of. It’s just that if the solar power could be used to meet energy demands or stored in batteries, that is a more efficient solution than using energy to clean the atmosphere (because otherwise the gap will be made up with fossil fuels which will be more costly in total energy) so for any economically rational environment (which are most places) where wasted energy is not being produced, we would need to invest in extra energy producing infrastructure in order to justify doing this.

And that’s ok, I think that such an investment could be profitable. It has plenty of positive externality effects too.

I'd agree that outside of California it might be problematic, but we have so much renewable in the grid it'd be trivial to do properly. I also think using excess power to remove carbon is ultimately a good idea.

I’m sure a lot of places have excess energy production that batteries can’t store. Gas is relatively easy to transport long distances. Seems like a variety of ways to decrease fossil fuel outputs seem likely. Then, at a future state, you could just do this as a way to terraform the planet (if that’s the right term?) back to a pre industrial state, as much as possible

Normally there is a small energy base load constantly generated below varying renewables and other forms such as hydro and fossil are dispatched as demand increases. Just because a utility has capacity for higher demand does not necessarily mean there is excess energy, generally the instantaneous energy generated is equal to the energy being consumed.

Carbon Engineering, in Canada, is already doing this on a pilot plant scale.[1] Converting CO2 to a fuel is chemically uphill, so you have to put energy in. This can work if you have cheap hydropower, which parts of Canada do. It's only feasible financially if there's a big subsidy for removing CO2 from the atmosphere.

[1] https://news.nationalgeographic.com/2018/06/carbon-engineeri...

Hi HN! I'm Rob, founder of Prometheus. Just saw this, catching up now and will try to answer any questions.

Hi Rob. Why bother trying to extract CO2 out of "thin air" when there are far more concentrated sources available, for example exhaust of existing power plants (100,000 ppm CO2, instead of 400 ppm)?

There are even streams of pure CO2 being vented to the atmosphere, eg: https://thewest.com.au/business/energy/woodsides-browse-lng-...

Point sources won't scale to the size of the problem. Easier initially, but to replace fossil fuels for transportation and heating, will need to get the CO2 from the air.

>Easier initially...

Then start with point sources initially.

Considering a good portion of transportation and basically all of the heating can be replaced by electricity directly, you will not need to go beyond point sources anyway.

There is a much more efficient way to deal with point sources, if you have a clean energy source in their neighborhood: just shut them down and replace the energy they provide with the clean energy you would use to scrub the CO2 from the air.

Yes, sometimes this is practicable. But many locations do not have sufficient renewable energy available, and nuclear has become unpalatable for a variety of reasons.

Scrubbing CO2 from boiler or turbine exhaust takes a small fraction (5%-ish) of the energy needed to convert it into fuel. If the source is a power plant, the CO2 can be captured at a cost of efficiency penalty of around 10%.

Once it is captured, storing and transporting CO2 to a location with abundant clean energy is also relatively simple.

"Unburning" CO2 takes energy. Where does your energy come from?

We use zero carbon solar and wind electricity. As long as the electricity source is zero carbon and low cost, it makes economic and practical sense to make zero carbon fuel.

So what is the efficiency of your process? How many joules of chemical energy do you get from 1 kilowatt hour? (i.e. 3.6MJ)

Ok but why not just use the zero carbon electricity, if you have so much of it?

They're going after the use case of gasoline as energy storage, not gasoline as primary energy production.

The reason, today, that cars are powered by gasoline and not electricity is not the cost of the energy itself, but the cost of storing it.

Obviously it would be better to use the electricity directly. But it's hard to get that electricity to a moving car on the road (or a plane in the sky).

It’s not that hard. You can just charge the car inductively with wires in the road, or better yet, just lay tracks for electric trains.

Your "not that hard" solutions don't solve the problem you answered to. You can't move a single (production) car out there with wires in the road, or by laying tracks.

Perhaps it's a bit harder then, after all?

There's a difference between a regular car and a hotweels toy

> It’s not that hard. You can just charge the car inductively with wires in the road

I’m sorry, are you proposing this solution as being cheaper than either gasoline or batteries?

How do you put electricity in your tank?

You seem pretty optimistic about the economics of your tech. Is that based on extracting CO2 from air or from more concentrated sources such as power plant flue gas?

The main question that I do not see addressed, is how many Joules of energy does the process need to make 1 Joule worth of liquid fuel.

If we need for example 2J of energy to make 1J worth of gasoline, then it means that we need to double the installation rate of renewable production facilities (wind, solar, biofuels), while the global energy demand increases. This makes it completely infeasible (and I did not consider cost at all in my analysis yet).

Edit: I just saw that the founder mentioned in the comments that they expect 50% efficiency at best. This unfortunately means that the liquid fuel product of this process will have at least double the cost of renewable energy.

That's a smart argument, but I think what it's missing is that the cost of gasoline is much higher than the cost of its energy equivalent on the electricity market. I.e, the cost of 1 Joule of energy != the cost of 1 joule of gasoline.

Because gasoline is a premium energy source, if we can produce it from photovoltaic sources, we can effectively mark-up photovoltaic electricity. In the long-term, that would make it economical to greatly expand our photovoltaic capacity. The cost equivalence Prometheus is aiming for is: Market price of 1 gallon of gasoline > cost to produce 1 gallon of gasoline using renewable energy.

Another factor is that Prometheus production works in remote areas where transmission losses for electricity are high (i.e., remote hydroelectric plants).

So, you spend a load of energy to reform atmospheric CO2 back into hydrocarbon fuel - and then just burn it again, turning it back into CO2 and putting it back into the atmosphere?

The end state of the atmosphere is, at best, the same as the starting state, but you've expended a load more energy for nothing. If the energy to run this process isn't zero-carbon, then this is going to be a big net emitter when done at scale.

This is just creating green-washed gasoline.

It depends on the alternative state of the universe. If the alternative state of the universe is you never drove the car, then you're right, this is not clearly better.

If the alternative state of the universe is you drove the same car but burned gasoline that was drilled out of the ground, then this is much better.

If you have a mechanism that can extract atmospheric carbon, at scale, without any additional emissions (which isn't really what this is...), then that carbon needs to go back into the ground, not back into the atmosphere.

We don't _just_ need to stop carbon emissions, we need to get the atmosphere back down to ~250ppm, from the current ~412ppm - we probably can't afford to wait ~two centuries for it to weather out naturally.

not if the initial energy source had a lower CO2 impact than normal gasoline. eg: The Gas making machine used solar or wind for input .

Now, I dont see the point over just using electric cars, but i guess this has a limited shelf life for those existing cars, or those who refuse to change?

Could also have continuing niche uses where energy density is paramount, like aircraft/rocket fuel and portable generators. e.g. the US military has been looking at biological or synthesized JP-8 substitutes for a while, for supply-chain risk reasons instead of environmental ones.

You don't have to burn it. In theory governments or environmental groups could simple buy and store it.

If you're not going to burn it, you should turn it into something else - carbonate rock, ideally.

Or turn it into plastics which is more useful.

To remove CO2 from the air, plant trees. Use the result as building materials. Develop hardier trees that can grow in areas now inhospitable to trees.

Besides, trees are nice. They're solar-powered, too.

I saw this paper http://energywatchgroup.org/wp-content/uploads/EWG_LUT_100RE... on HN recently which claims that it shouldn't be too expensive to convert to 100% renewable energy by 2050 (but you have to actually start on it of course). Liquid fuel would still be used for ships, jets, rockets, and some trucks and to be net zero carbon that fuel needs to be produced either by plants (biofuel) or by Prometheus-style direct capture. In this case the fuel is not a source of energy but a denser storage medium for renewable electricity.

I really hope this is successful because this would make a difference for climate change much quicker than transitioning to BEV cars. BEV cars are better overall, but there just isn't enough time with the rate climate change is happening.

This combined with a strong push for PHEV and hybrid cars could help climate change much faster. It makes sense on many levels:

* PHEV cars with 40+ miles EV range are great for those who can charge at home. It's enough to make most of the miles electric (such as commuting or getting groceries). And it's a much better use of limited lithium battery capacity. The battery in one Tesla could be used to build 10 PHEV cars.

* Many people still live in places with no overnight charging such as apartments and dense urban areas. The hybrid tech (perfected by Toyota) is the right solution here. Keep working on getting the mpg even higher.

* Government can really boost this by requiring X% of all gas to be carbon neutral and increasing that over time. They do this with 10% ethanol, but that was the wrong fuel. Start with 5% must be carbon neutral and increase 5% every year from there.

* Carbon tax, enough to make synthetic fuel like this competitive with fossil fuels from the ground.

BEV cars is a case of perfect being the enemy of good. When excluding external factors, BEV is clearly superior to ICE. But we don't have time to transition to BEV. We need to make progress on climate change now and this will get there faster.

There is a water plant called Azolla that actually captured so much co2 long ago that many think it triggered an ice age. Why not incentivize natural carbon sequestration and just produce huge fields of this stuff everywhere? I would hope we find a fish that likes eating it, or find a way to convert it into other animal feed, if nothing else. I don't think carbon tax credits or whatever they are called are enough for someone to justify making an actual sequestration-only operation.

If an animal eats it, wouldn't it be combusting the captured carbon to produce CO2/H20/energy? I don't think you'd want to feed it to anything, but just let it be buried or be pushed under the earth's crust.

Yes, they don't even need to eat it, just from decomposing versus growing corn you can measure the rising and falling cycles of co2 at different times of the year for north america. I think Azolla is still less effort to grow than most plants, which might still help out if it ends up being used for animal feed.

I wrote the comment below in response to another article, but it is applicable here. I should note that the technology to convert CO2 to say hydrocarbons is well known (and my current work is on making it economically interesting), my issue is with trying to extract CO2 from the atmosphere, which is very inefficient.


This is actually a very bad idea and a complete waste of money which should have been used for other projects. It reminds me of another bad idea, which just will not die - extracting water from air by cooling it. Right now, we have several technologies ready to go. Starting with the most cost-effective, and omitting the "use less" scenarios:

1. Replacement of fossil fuel power plants with carbon free electricity such as wind and solar power (also geothermal, where possible and nuclear, where palatable). Cost per tonne of CO2 saved: less than zero for about 30% of current generation, and "very low" for a good portion of the remainder.

2. Sequestration of concentrated CO2 streams, such as those produced in natural gas processing. Cost: $20-$40 per tonne.

3. Biosequestration, ie tree planting. Cost varies greatly, maybe $15-$50 per tonne.

The approaches above are the only ones that are actually used in the industry today, but there is plenty of room to do more. The approaches below are considered to be economically prohibitive, and AFAIK are not in use:

4. Post-combustion carbon capture: Scrubbing the CO2 from exhaust gases of power plants etc, where the CO2 concentration is 10-20%. Cost: $50-100/tonne, PLUS the cost of sequestration, as above.

5. Pre-combustion carbon capture: here, the carbon is removed from the fuel and sequestered, and only the hydrogen is burned. Cost: $80-150/tonne, but sequestration cost is low.

and then we have:

6. Removal of CO2 from the atmosphere. The article says the cost may be "under $100/tonne", but the serious estimates I have seen are circa $500/tonne. Consider that the CO2 concentration in air is around 0.04%, cf post combustion concentrations of 10-20%. Regardless of the advances in technology, this will never be as cheap as post-combustion carbon capture, which is essentially the same process but with 250 times less throughput.

You are missing the point; this is a fuel production system that effectively removes the need to capture carbon: i.e. the notion of turning air into something you put in the ground too offset the carbon we are removing from it to burn. I agree that is not a valid economical proposition other than making people feel slightly less guilty about burning fossil fuels. It's actually a rather dumb idea since you are taking something that is expensive and wasteful and spend yet more to offset somewhat just how wasteful it is.

Producing fuel from the captured carbon, sidesteps the whole problem of needing fossil fuels at all. So, you are not offsetting anything; you are simply producing the fuel that you need in a way that is clean.

You seem to be arguing that it can't be done because 'numbers'. 1) those numbers lack citations 2) they are not set in stone. The question you should be asking yourself is how badly wrong your numbers are and what it would take to make the numbers right.

Turns out that this whole game of producing fuels from thin air is mostly a function of clean energy cost per kwh. Simply put, this is not constant. It varies wildly geographically. And it's also not constant over time. It's been dropping for decades at a rather impressive pace and projected to continue to do so. So, the only question is when will it become completely uneconomical to mine fossil fuels as opposed to simply converting co2 into whatever carbohydrates we need.

I'm guessing the persons behind Prometheus might be a bit optimistic here (i.e. suggesting it could be economical right now) but I wouldn't see that as a fundamental issue. If the answer is that those cost lines cross anywhere in the next decades, this would be still be an extremely lucrative investment. The mere possibility that this could be economical right now or in the very near term, makes this quite exciting.

>You are missing the point; this is a fuel production system that effectively removes the need to capture carbon

No... the first step in the proposed process is to capture the CO2 from the air, what I describe in point 6 of my comment.

>You seem to be arguing that it can't be done because 'numbers'

No... It can be done. But it should not be done. Because 'numbers' tell you there are other things that should be done instead. Right now.

>those numbers lack citations... you should be asking yourself is how badly wrong your numbers are...

I work in this field. I have literally hundreds of possible citations. Pick a number you most disagree with, and I will provide you a citation. Alternatively, provide me a counter-citation and I will review and comment on it for you.

> The mere possibility that this could be economical right now or in the very near term...

Here is what I am trying to tell you: this cannot be economical until all the other, much more economical options which I have listed are pretty much fully used up. Considering that we have barely made a dent in the first of these, this will certainly not be economical in the near term, or in the medium term (and in my opinion, never, because biosequestration is so much cheaper).

Eh no. You are talking about carbon capture as a way to offset fossil fuel consumption. I'm talking about reducing fossil fuel consumption by instead producing non fossil fuels. Apples and oranges. The point of that is not to capture the carbon but to utilize it as fuel. With this technology, that is neither impossible nor prohibitively expensive/unecomincal. Unlike the six schemes you outline that are about not producing any fuel whatsoever so we can continue to produce it the old way while hopefully removing some of the CO2 that we are thus putting there (hence the need to capture it).

You're using numbers to categorically dismiss what seems to be a pretty well reasoned case for doing this as "impossible" because 'numbers' for various carbon capturing schemes.

If you are capturing carbon, you might as well do it in a form where you can actually utilize it for fuel. That's a pretty nice proposition. Prometheus seems to be one of several startups with some plans for making this happen.

You're saying they are wasting time. I'm saying that layering the cost that you outline on top of the existing fossil fuel production cost only makes their value proposition even more attractive than it already is without doing that. Bottom line is anything that reduces the amount of oil we pump up and burn is a good thing. Carbon capture schemes seem more like an excuse to drag our heels doing that than something that is actually likely to produce results on a timescale that isn't measured in centuries.

>The point of that is not to capture the carbon but to utilize it as fuel. >If you are capturing carbon, you might as well do it in a form where you can actually utilize it for fuel.

Do you understand that the Prometheus proposes to first capture the carbon and then convert it to fuel?

I have no objection to the "convert it to fuel" part. Just to the capture from atmosphere, which is the most inefficient way.

I understand you perfectly. I just don't agree with a single sentence of it. The semantics of carbon capture for you seem to mean to capture some (tiny) percentage of the absolutely epic levels of fossil carbon we put into it today.

The point of Prometeus is to take no fossil carbon whatsoever (0%) and create the fuel directly from the CO2 already in the air and indeed put it back there when it is burned. It's not capturing so much as reusing what is already there. It's by definition the most efficient way. It's 100% efficient.

None of the things you listed actually produce fuel. So they are 0% efficient. At best they offset some meaningless percentage of fossil fuels. Actually raising the cost of those fossil fuels to pay for more meaningful percentages (like more than 1 digit?), just strengthens the business case for Prometheus. The more costly fossil fuel gets, the more attractive Prometheus gets. As it is, they seem to be claiming to be cost effective as is.

>I understand you perfectly.

I don't think so.

>I just don't agree with a single sentence of it.... The more costly fossil fuel gets, the more attractive Prometheus gets. As it is, they seem to be claiming to be cost effective as is.

Okay. Invest in Prometheus. I think the net result will be an increase in CO2 emissions, because all the activity will fail to deliver any viable atmospheric CO2 capture plants, ever. Let's check on this say 20 years from now. If I'm right, buy me a beer.

OK, I was curious so just did some math.

Gasoline has energy density of 34.2 MJ/L, or 9.5 kWh/L[1]. Its retail price is about $3/gallon, or $0.8/L.

So, assuming 100% efficiency, the energy source for making gasoline should be ~$0.084/kWh to break even.

Energy Information Administration (EIA) estimates 2022's solar/wind generation cost at $73.7 and $55.8 per MWh [2], or $0.0737 and $0.0558 per kWh.

Assuming wind power, gasoline generation has to be ~66% efficient to break even, which is (I guess) not physically impossible, but an incredible engineering challenge.

...and that's assuming retail price. I'm not an energy expert, but [3] seems to say that gasoline's current bulk price is ~$1.5/gallon, which pushes the technology firmly on the side of losing money.

[1] https://en.wikipedia.org/wiki/Energy_density

[2] https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...

[3] https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=pet&s=e...

If there were realistic competitors for fossil fuels, we wouldn't be worrying about a climate crisis in the first place. Nothing is going to compete with pumping fuel out of the ground, and it never will.

Any realistic scenario starts with some kind of regulation on carbon extraction and then worries about the economics of replacements. And technologies like this one that claim to be within a factor of two seem very worth investigating.

Whether it works or not, who knows.

But all these renewable energy sources are already competing with fossil fuels and sometimes even winning! And even with these sources you can't make synthetic gasoline economically viable.

That leads to the question: if one can sell synthetic gasoline at profit, they must have a really cheap source of energy, in which case why go through the trouble of gasoline instead of selling the energy directly?

Imagine a remote military outpost-- the only supply chain access is limited & expensive.

Having vehicles that can go from empty to full in seconds by fuel you pulled out of the air yourself with solar panels last week could be much more valuable than using those same solar panels to charge an electric vehicle (or a battery bank and then later a vehicle).

Certain types of municipal or commercial fleets also have quick-refuel requirements. There are likely a few other limitations to current electrics that ICE engines don't have, as well.

Pumping oil has some big advantages, but procuring & distributing refined gasoline, propane, etc from crude is not exactly trivial or free.

There might be political advantages to having a proven process with proven cost. $40/ton carbon tax is awfully arbitrary... Until carbon can be captured for $40/ton.

A couple of issues with your numbers. 1) you are basing yourself on average grid prices in the US and the local cost of petrol. You should instead be looking at dedicated clean energy installations that you'd be using 100% for fuel production in places where that are optimal/ideal to do so. 2) those petrol costs exclude taxation that would apply in e.g. the EU. Current prices in e.g. Germany for a liter of petrol are around 1.20 euros. Much more in e.g. the Netherlands, which taxes much more aggressively. Bottom line is that petrol is really expensive already in a lot of places and not likely to get cheaper when people are getting worried about global warming.

So, petrol is a lot more expensive in a lot of places and clean energy is a lot less expensive in a lot of places. I'd say, we have about a 3-6x margin of error here. And that's just at the current rates.

Luckily, clean energy cost is dropping rapidly and projected to continue to do so for quite some time. The EIA's estimates appear to be averages for the US in the context of grid electricity. There are already places in the world where those prices are far lower (i.e. by magnitudes) and projected to drop even further.

Solar grid prices in places like e.g. Dubai, would be something like 0.024$/kwh. That number might already be obsolete. So, well below what you seem to consider the break even point. Even at 30% efficiency (as opposed to your 100%) this is starting to look pretty feasible. The Prometheus founder seems to be suggesting 60% is the efficiency rate elsewhere in this thread.

Boom economically viable right now in Dubai. A region well known for its dependence on crude oil exports. How cheap would this have to get for them to not bother pumping oil out of the ground anymore at all? Incidentally, they are already using solar to power those pumps (burning oil/gas to do the same is already uneconomical). They could be producing petrol with that energy directly instead. You have to wonder at what point that starts making more sense and what that would do the global oil/gas markets. I think it's more a question of volumes/scale than cost.

So, this is not "an incredible engineering challenge" but a simple matter of how soon the cost lines cross and economies of scale. Depending on your point of view, this may already be cheap enough right now. The point is kind of moot because by the time production is ramped up to the point where this has meaningful impact, energy cost per kwh will have come down much further whereas crude oil and associated taxes are not anywhere near as likely to go down or even stay the same. I'm guessing ramping this up will take quite a bit of time (2-3 decades?). In the process, economies of scale, will impact the pricing some more.

You say as if 30% efficiency is an easy goal, but the most efficient fossil power plants reach ~60% (from what I've googled). That's the best efficiency we get for just burning fossil fuel, a technology perfected over a century. Here we're talking about a technology that might (or might not) have been proven in a lab.

Also, a likely outcome of lower energy price is that consumers will simply bypass fossil fuels. People won't buy gas-powered car if renewable electricity is much cheaper. So, basically, if renewables aren't cheap enough, you can't make profit. If they are cheap enough, they take away your customers.

I'm not convinced that anyone can make money out of this.

Petrol and diesel are not the only form of carbo hydrates in our economy. I agree EVs will likely replace ICE vehicles long before this scales. However, oil is used for a lot of other things as well in our industry, including e.g. plastics, solvents, etc. So having this will help on that front while also allowing us to continue to use combustion engines where that still makes sense. As an energy storage mechanism, petrol/diesel still offer pretty decent energy density. If it can be created cleanly and cheaply, the price won't matter that much. At 1 $/gallon, nobody cared about fuel cost. Hence the popularity of enormously inefficient cars in the US. This stuff has the potential to be cheaper still.

The only serious solution to climate change is leaving carbon fossil in the ground. You are trying to create an incentive to have even more CO2 in the air just for the sake of profit.

The carbon costs of manufacturing a replacement fleet of cars is surely vast.

Meanwhile, the internal combustion engine is perfectly capable of running on a whole slew of renewable fuels, including but not limited to hydrogen gas, methanol, etc.

It's not the most efficient in the long run, but it's a piece of the puzzle, especially when you consider the baseline energetic/carbon costs of building new vehicles from scratch.

P.s. lithium is a conflict mineral now.

>P.s. lithium is a conflict mineral now.

I'll try not to mention it next time I am in Cornwall then, so as not to start a fight - https://www.cornishlithium.com/

The point about the desirability of a direct liquid fuel replacement for transportation is valid, but this logic doesn't work:

> The carbon costs of manufacturing a replacement fleet of cars is surely vast.

Cars have finite lifetimes. You don't replace the ones on the road, you replace the ones we'll buy in the future.

And this one... well...

> P.s. lithium is a conflict mineral now

citation REALLY needed

> Cars have finite lifetimes. You don't replace the ones on the road, you replace the ones we'll buy in the future.

Apologies... I realize upon rereading what I wrote that it was all a little hyperbolic.

My point is that renewable hydrocarbon fuels could extend the use of already manufactured cars in a way that saves energy on the supply end, much in the same way that thrift stores extend the lives of worn clothing and satisfy a lot of demand that might otherwise go toward pressuring suppliers to make new clothes. It pays, energetically, to reuse and recycle (two out of the three R's right there!) Renewable hydrocarbon fuels would effectively "recycle" existing cars. I don't have any hard numbers but my hunch is that economically this could be quite a significant effect.

Combined with hybrid conversion kits, renewable hydrocarbon fuels could make existing vehicles into a viable piece of the sustainable transportation puzzle.

> citation REALLY needed





From the mouth of the beast itself: https://www.voanews.com/a/afghanistan-trump-mining-lithium/3...

Those links all just say that there's Li in Afghanistan. Calling it a "conflict mineral" is a particular term of social justice that implies that its extraction is directly related to the exploitation of some local population, not just that there's a putative "conflict" nearby! You just seem to be using the term to argue that people near wars should be economic pariahs who we never trade with. That's harmful, not helpful.

An of course, the overwhelming majority of Lithium production and reserves in the world are in Australia and Chile, which are notably conflict-free.

That's a disingenuous reading of "all those links". In the very first link, for example, we have this quote:

> The existence of this historical data suggests minerals may have been an underlining factor in the administration’s decision-making long before their official entanglement in the Afghan conflict. That would explain why, mere weeks after 9/11, and weeks before the official declaration of war, the Pentagon was already commissioning geologists to study caves throughout the country. ...

> ... The process began almost immediately. From 2004 to 2006, the USGS conducted airborne geophysical surveys of the country. This was supplemented by efforts between 2005 and 2007 to consolidate existing information about the deposits in tandem with the AGS. What they found shocked even seasoned geologists, with an internal Pentagon memo from 2007 referring to Afghanistan as a “Saudi Arabia of Lithium.” With peaked interest, experimental hyperspectral imaging surveys began in 2007. But by the time Bush’s tenure as president was over, those surveys were not yet complete.

I'm sorry, where in that quote is someone making the case that we shouldn't trade in Lithium because it's bad for Afghanis? Again, you're making a very specific claim about social justice here and seem to be justifying it with bland pronouncements about Afghanistan. That doesn't fly. Find me someone credible demanding divestment from Afghani Lithium or battery boycotts or something and we'll talk.

But no, I'm not going to just take the word of some rando HN poster that somehow Lithium is to be avoided. Like I said: citation needed.

That quote is implying that mineral prospects, notably lithium, were a key consideration in the U.S. decision to go to war in Afghanistan. Stick your head in the sand if you'd like. This is an ongoing war that has cost hundreds of thousands of lives. If that's not conflict, I don't know what is.

I didn't say "lithium is to be avoided". I didn't make any prescriptions. My point is that lithium is not renewable and has been of key interest to geopolitical strategists for decades. And yes, it has motivated deadly conflicts. This is only going to heat up as time goes on.

I'm not advocating that anyone "avoid lithium". It's just not a renewable resource and people have fought over it. They will continue to fight over it.

(Afghanistan isn't the only place where people have fought over lithium: https://www.freetibet.org/lithium-tibet )

An important point that people are missing is that by capturing carbon directly from the air with electricity we can combine two very important energy systems: electrical and chemical. Going 100% renawable at an accelerated pace is within reach and if we could use all excess power due to intermittency to transform the carbon dioxide and synthesised hydrogen into hydrocarbons we can solve some other problems that are currently unsolvable before 2050 (jet fuels, chemical industry).

Also if we've improved this technology so that the costs are reduced (50$ per ton) we can do proper negative emissions in a scalable way without many downsides (can be used in non-arable land, no water consumption with low temperature direct air capture actually has water as a co-product which we can use for electrolysis). We could then sequester the carbon dioxide underground or even create carbonates out of them so we can store them safely in concrete or asphalt in the form of aggregates.

This is one of the very few areas where SV traditional 'startup' thing could actually work and make big difference in the energy as well as environmental field. Other might be battery tech but there are too many serious big competitors there with 100 years of experience, and ample self-funding... But CO2 removal producing fuel from electricity is one such field - it's not taken seriously enough by big players who more pretend to be working on it than they are actually working, it's really overlooked, and there are absolutely zero fundamental reasons why it can't work. And it goes hand in hand with renewable energy, to make perfect use of energy overproduced by intermittent sources, straight on site. Solar cells cost almost nothing, but there is lack of transmission capacity, grid is imbalanced, and corrupt permissioning process is hard to navigate through? Just put that thing straight on site and collect the gasoline once a week using a truck.

If I wanted to assess my carbon footprint, and the cost to offset, and then pay to actually fund mitigation, how would I do that?

Eg this doesn't seem fully credible, but is responsive https://www.terrapass.com/product/productindividuals-familie...

I believe you're looking at this the wrong way around. The consensus is that buying carbon offsets only works as the last resort, only after you've taken all of the steps to reduce your output in the first place - fly less, drive less, eat less meat, eat local produce, reduce the amount of products you buy. If you're buying a carbon offset to feel better about your lifestyle, you probably shouldn't bother.

After that, you still need to look into the actual product you're buying into directly and ensure that they're doing what they say they're doing, and that the programs are managed correctly (which is very difficult to do).

In terms of calculating your CO2, https://www.carbonindependent.org/ is pretty good for the UK. I'm not aware of an equivalent for the US though (sorry)

- http://theconversation.com/carbon-offsets-can-do-more-enviro... - https://www.theguardian.com/environment/2011/sep/16/carbon-o... - https://www.independent.co.uk/life-style/motoring/is-carbon-... - https://www.nrdc.org/stories/should-you-buy-carbon-offsets - https://www.abc.net.au/news/science/2018-04-11/carbon-offset... - https://theenergymix.com/2017/04/25/carbon-offsets-dont-redu...

Converting carbon dioxide into hydrocarbons consumes energy. If the product is simply burned for fuel, I can see no benefit to this effort at all. Energy will have been consumed and carbon will be re-released.

What am I missing here? All I can see is a battery in the form of gasoline. And its efficiency remains to be seen - assuming the process actually works and can scale.

That's exactly the point, we could keep using existing planes, trains, cars, ships, trucks, etc. without releasing new carbon.

Electric cars are just now practical and available for most people, but without radically improved battery tech we can't make practical electric airlines for example.

Plus, it makes carbon capture tech cheaper.

In that case, carbon capture to produce organic chemical feedstocks makes a lot more sense than burning for fuel. Given that there's no information about what the process entails, it's hard to draw many conclusions.

Energy storage has value.

I strongly suspect that manufacturing hydrocarbon fuel out of air, water, and electricity is going to be a pretty significant part of the fight against climate change.

The reason is fundamentally political. Newly industrialized countries have a lot of vital economic activity dependent on internal combustion engines, and cannot afford the luxury of replacing them with alternatives. The West does not have the political will and power to worsen starvation in India in order to lower the CO2 emissions caused by engines manufactured and used in India. It's a lot more feasible to subsidize carbon-neutral fuel generation schemes until it's cost competitive for Indian consumers.

In other words, this kind of scheme can be used to essentially ship CO2 emission reductions from one country to another. It replaces a wicked problem with complex political and social components to a mere application of staggering sums of money and resources.

>I strongly suspect that manufacturing hydrocarbon fuel out of air, water, and electricity

If you already have electricity, that is all the energy you need. There is no need to use it to produce a toxic, polluting fuel that is used in highly inefficient internal combustion engines. Simply use electric motors, which are way more efficient.

> If you already have electricity, that is all the energy you need

If you can store and transport it better than gasoline can be stored and transported, which ... so far you can’t.

The grid is a thing...

Why not just build electric trains?

That is problematic in areas, including much of North America.


Which of the issues do you think that addresses?

Electric motors are efficient, but current battery tech is not. Hydrocarbon fuels will probably always win for weight to energy efficiency.

>Electric motors are efficient, but current battery tech is not. Hydrocarbon fuels will probably always win for weight to energy efficiency.

You are misinformed, or focusing on the wrong metric. There's a detailed rundown of efficiency for different technologies here:


Sea and air transport, as well as remote-location generation, and several industrial processes, rely on or benefit greatly from fuel or hydrocarbon-based inputs.

Forgive me for pointing out the obvious, but we already have an existing supply of hydrocarbon based fuels which are relatively cheap compared to the proposed "quest."

They are destroying the environment on which we depend. They are also finite.

To further point out the obvious.


They are finite but the finite total is over five times the amount needed to utterly destroy the environment... so we need to refrain from using up that finite total.

Whch alone is a sufficient response to your earlier question: https://news.ycombinator.com/item?id=19794993

How would someone in China charge their electric car with clean electricity generated in the United States?


Nobody suggested what you are asking about.

But it seems you are suggesting that rather than generating electricity locally by sustainable means, it would be a better idea to create synthetic gasoline in the US, then ship that to China for them to burn?

>Nobody suggested what you are asking about.

That is exactly what I was talking about it my original post. No matter how many cars in the US get replaced with electric ones, China is still going to be building and driving gas-powered ones, and we have limited influence on their domestic policy.

>But it seems you are suggesting that rather than generating electricity locally by sustainable means, it would be a better idea to create synthetic gasoline in the US, then ship that to China for them to burn?

Not at all. In fact, the very first prerequisite for what I'm talking about is that the US has switched entirely to nuclear, wind, solar, hydroelectric, and other non-CO2 emitting power. At that point, there's little the US can do further reduce global CO2 emissions, at which point generating extra electrical capacity and using it to synthesize ICE fuel starts to look really attractive.

And again, this isn't something that is necessary or even viable in the short term. Over the long run, however, it seems like an important way that more industrialized nations can lower the CO2 emissions generated by internal activity of less industrialized ones.

It costs only 1% of the energy capacity of liquid hydrocarbon fuel to ship it literally around the globe. A penny per dollar of delivered value.

The chemical potential energy stored is proved stable for literally hundreds of millions of years. Few electrical energy storage options are useful for more than a few weeks, most operate in the range of seconds to hours.

The fuel and its combustion products are remarkably non-toxic (though excess accumulation at the scale of the globe over decades to centuries can be quite problematic). They don't attack or degrade most materials used in the construction of storage, transfer, processing, or utilisation.

The source elements are abundant and relatively easily obtained.

There is a vast infrastructure and 1-2 centuries' experience in working with and applying the materials.

The energy densities by both weight and volume are all but wholly unmatched by nonnuclear energy sources. Only hydrogen, by mass, is higher, and it presents numerous other challenges.

Fossil fuels have proved exceedingly problematic. We must stop using them for combustion.

Liquid and gaseous hydocarbons are amazingly useful and flexible. While they may be substituted for in some applications, it's likely that a base-level need will remain.

Electricity is an amazing power transmission and transformation technology, and is exceedingly useful in informatiin technologies. It does exceeding poor at storage, though, and likely always will, for reasons of basic physics and chemistry.

It also creates a useful product to offset the development of carbon capture.

The $3.00/gallon price doesn't pass the sniff test, please tell me what I'm missing:

1 gallon of gas is 33kwh of energy

1 kwh of electricity, wholesale in the US, is approx 3-8 cents or higher, so 1.65-4.4$/GEG of electricity

CO2 to gas process efficiency electrochemical would be optimistic at 60%

CO2 sequestration from air costs 40-120$/tonne, optimistically estimated from not-yet industrially available technology. That scales by approximately 44/14 or 3x (weight CO2 to CH2) so 120-360$/tonne gasoline. At approx 2.8kg/gal (350 gal/tonne) that is an additional 0.34-1.02$/gal.

So before research amortization, capital, operations, maintenance, transport, and profit I'm seeing an optimistic best-case of a >2$/GEG production cost.

This is of course assuming they can actually do what they are claiming. And that they can do it at scale, at meaningful throughput, and with process stability.

Prometheus, who made humans from clay, and them gave humans fire because he felt compassion for them.

So, named after nothing less than the creator of humans and origin of civilization.

PS: As a punishment for giving fire to humans, Prometheus was chained to a mountain and had his liver picked out by an eagle every day, until Heracles rescued him.

To me the main lack is why put these machines where the carbon is scarce vs abundant? Eg: My back yard has something like 411PPM [1] but a coal plan flue, i assume, has a very much larger PPM.

IMO it's analogous to solar panels in Canada where the sun is 1/2 the strength of other parts of the planet [2]

[1]: https://www.co2.earth/ [2]: https://en.wikipedia.org/wiki/Solar_irradiance#/media/File:G...

that entire article can be reduced to "nanotubes"

since its a YC company though maybe we could get the underlying story?

Hi, this is Rob, Founder of Prometheus. There is more info on the podcast that accompanied the print piece here: https://megaphone.link/BLM3585271197

I'm also working on a HN launch summary that will fill in more details.

hi rob, thanks for responding.

unfortunately i sat through that 20 minute podcast and the only thing i learned was $3/gal is your estimate and that the machine has not yet worked. nothing about nanotubes or any attempt at a claim at what the innovation is here.

looking forward to that launch summary

I emailed Rob this afternoon to set up a Launch HN thread, where people will be able to ask whatever they want. Hopefully he can show up to answer some of the comments in the current thread too, since people are obviously interested.

Thanks! Working on answering questions now. (Rob)

“Nanotubes + marketing budget”?

In all seriousness, I hope there’s more to it than that. I just can’t help feeling like nanoscale carbon is the blockchain of chemistry.

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