Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline • Hacker News Board

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#551

Post by shawabawa3 » Tue, May 07, 2019, 3:14 PM UTC

ossie wrote: post #511

ascar wrote: post #474

Earlier quoted context omitted.

> I also think this innovation has a larger impact if it were used to bring existing generators of emissions closer to being carbon neutral. It also reduces the burden of being cost efficient on Day 1 since the carbon intensity of large emission generators is already a cost they'd be glad to mitigate or get rid of I can't follow this argument. What exactly are you proposing? His process still has a ~50% efficiency-lo…

In its base form this technology is mining a resource - carbon. Would you rather mine in areas of low or high atmospheric intensity? Would you rather capture it where you fund the whole operation yourself, or where someone else (existing polluters) is willing to pay you to take it out of the air because there is a regulatory cost to them putting said carbon in the air? Maybe i should have been clearer. I wasn't sugge…

I imagine the only places you can realistic install this technology is next to hydro dams/large wind farms where you can get very cheap electricity at certain times, and there are likely no hydrocarbon plants in these areas.

I'm not sure it's reasonable to install this in a coal plant and try to source cheap solar from hundreds of miles away to power it (if that were possible, why would the coal plant be active? It can't compete with the energy you're using to scrub it)

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#552

Post by shawabawa3 » Tue, May 07, 2019, 3:22 PM UTC

Zenbit_UX wrote: post #525

rmcginnis wrote: post #514

Earlier quoted context omitted.

The energy content of the gasoline is less than the energy used to make it (only 50-60% efficiency), but the CO2 released is the same as the CO2 used. So the energy efficiency is low, but the net CO2 emission is still zero.

Is your device small enough that it could be placed to filter the exhaust emissions from a fuel burning car and reinsert the newly created gasoline into its fuel tank?

powered by what? It would only make sense if there was a carbon free cheap power source you could use to charge it - if you just take it from the car battery you're wasting fuel as it's only ~50% efficient

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#553

Post by simonh » Tue, May 07, 2019, 3:39 PM UTC

rmcginnis wrote: post #547

thinkcontext wrote: post #541

Earlier quoted context omitted.

But first you have to cross the valley of death. Elsewhere you refer to having to limit capital spending, wouldn't getting CO2 from a 3rd party instead of building a massive air capture facility do that? Everything I've seen says that its cheaper to capture from a point source than from the atmosphere, why would you make your costs higher than they need to be? You can of course build air capture down the road but I'd…

Yes, we're actually agnostic on CO2 source. To get to scale we'll need to use CO2 from direct air capture, but we could by the collection from someone else.

I can completely see the logic. If this only works for point sources it may not scale sufficiently to be viable long term. So that capability needs to be proved out early in order to demonstrate it's long term value to investors.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#554

Post by dodobirdlord » Tue, May 07, 2019, 3:51 PM UTC

erobbins wrote: post #400

jonnycomputer wrote: post #381

Earlier quoted context omitted.

If this process were to only make transoceanic shipping carbon neutral it would be well worth it.

Except fuel oil used in shipping is like $1 per gallon or something similarly low.

That said, for bulk low-quality fuel needs like shipping they could reduce costs by skipping the upcycling stage and just burning the alcohol.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#555

Post by zaroth » Tue, May 07, 2019, 4:01 PM UTC

docker_up wrote: post #544

zaroth wrote: post #176

Earlier quoted context omitted.

Battery replacement is not really a factor under any kind of "normal" use. One Tesla owner driving for Tesloop was able to burn out a battery after extensively (exclusively) Supercharging from low charge to 95-100% charge after about 350,000 miles. Maintenance cost over that time was calculated as $0.05/mile. [1] With V3 Supercharging, you can drop in with your Model 3 at 15% and be at 80% in 24 minutes. In my road t…

How long are you waiting in line to get a chance to charge? I've been driving with my friend with a Tesla and he visited 2 places before giving up because the line was too long.

I wouldn’t know, I’ve only gone the one time.

I do expect that they will figure out a reservation system which tracks and queues vehicles en route, like an air traffic controller, to cut down on inefficient ad hoc queueing at the location.

It would be super fun to program such a system, backend and front. Even more so as the cars become increasingly autonomous.

For now at least you can click on the map and see live how many chargers are in use.

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#556

Post by Robotbeat » Tue, May 07, 2019, 4:11 PM UTC

effie wrote: post #520

Robotbeat wrote: post #434

Earlier quoted context omitted.

At high altitude, the water stays up long enough and has such a huge impact that even its long term averaged impact is greater than the CO2.

Could you give a source for that? My understanding after some search is that effect of high-altitude water is hard to evaluate. I agree that at high altitudes contrails may evaporate and the water then may not fall down... Is it possible that jet exhaust water vapor accumulates in stratosphere? That would be terrible.

It is hard to evaluate, but of course being hard to evaluate does not mean it's not a real thing.

The effect (not counting contrails) is about double the effect of CO2 emissions alone. Including contrails, it may be even higher. There are mitigation strategies to deal with these non-CO2 radiative forcing effects, though it's very complicated.

Good article: https://www.carbonbrief.org/explainer-challenge-tackling-avi...

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#557

Post by Robotbeat » Tue, May 07, 2019, 4:11 PM UTC

codethief wrote: post #501

Robotbeat wrote: post #434

Earlier quoted context omitted.

At high altitude, the water stays up long enough and has such a huge impact that even its long term averaged impact is greater than the CO2.

I have been completely unaware of this effect. Could you provide me with a source where I can read up on this?

Good overview: https://www.carbonbrief.org/explainer-challenge-tackling-avi...

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#558

Post by 0000011111 » Tue, May 07, 2019, 5:45 PM UTC

rmcginnis wrote: post #311

0000011111 wrote: post #307

As a person with a background in Environmental Studies, a c o2 to fuel conversion technology such as this sounds revolutionary! I am most curious about the fundementals. Can you give us more specifics on the process such as; 1. What is the scale of the operation? Does this process need to be done at a large scale to work out economically? 2. Take a Boeing 737 for example which has a fuel capacity of ~6,875 Gallons. H…

The smallest scale at which we can operate profitably is probably in the 100,000 gallon/year range, although that could go down over time. We will make modular, mobile systems that don't have to be very big to be profitable. One shipping container will likely be able to do 100,000 gal/yr for example. The electricity required will be approx. 60 kWh/gallon.

That shipping container model would be ideal for remote villages in Alaska! Making fuel locally would be so much more energy efficient!

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#559

Post by joshdance » Tue, May 07, 2019, 5:50 PM UTC

Can normal people (like me :) support the effort of invest?

Re: Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline

#560

Post by seppel » Tue, May 07, 2019, 7:17 PM UTC

pfdietz wrote: post #495

seppel wrote: post #383

Earlier quoted context omitted.

My personal pet theory is that the energy consumption is more or less equivalent to the price. So as long as the solar panel is not economically viable, it does not provide an energy surplus. 20MWh is not much, it's $500-$3000 worth of energy, depending on taxes and stuff. Can you buy, install, connect, maintain, clean a 300W solar panel for 20 years for this price? Edit: Also, 20MWh is quite high. That's 9h of perfe…

"My personal pet theory is that the energy consumption is more or less equivalent to the price." This implies that energy is the only input to making PV, which is clearly wrong. Or maybe you're saying that if we trace back costs into the economy, from the workers, to the grocery stores where they buy their food, to the farmers, etc. etc., it all eventually comes back to energy. In that case the energy return on inves…

> Or maybe you're saying that if we trace back costs into the economy, from the workers, to the grocery stores where they buy their food, to the farmers, etc. etc., it all eventually comes back to energy.

Yes. Of course, this is greatly simplified and I'm not entirely sure where to put capital costs in my theory. But I think I'm not too far off. And of course I'm purely talking about energy, not whether it is environmentally friendly or not.

> In that case the energy return on investment is going to be 1:1 in steady state, which indicates that's not a useful metric either.

I'm not sure what you mean by this. If I pump up a barrel of oil from the ground, I end up with more energy than I started with. Otherwise I would not do this in this first place, because I could not make money.