Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

news.ycombinator.com

Post reply on HN
Print view View original

471–480 of 589 posts

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

#471

Post by Grustaf »

rmcginnis wrote: post #13
Grustaf wrote: post #4

So you are competing with batteries? I suppose batteries have much higher roundtrip efficiency, but maybe there are other advantages to your technology, like being able to rely on combustion engine cars?

The main advantage of renewable gasoline over batteries is that we can decarbonize the existing vehicle fleet without replacing it. Also, the very high energy density of gasoline, diesel, and jet fuel will make sense for a long time in Jet aircraft, long haul trucks, and ocean container ships, for example.

Now for aircraft I can see how it makes sense, but anything ground based could easily be electrified.

Another thing, will this synthetic diesel burn cleanly like hydrogen or do they need to add lots of nasty stuff?

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

#472

Post by mr__y »

rhinoceraptor wrote: post #429
crankylinuxuser wrote: post #132

Earlier quoted context omitted.

If the ev car companies got their shit together, they could have used swappable battery packs. You can wait around for 12h to charge, or you can turn in your cores and pay for 100% capacity batts now. And the swap would be quicker than standing around filling up a tank. But no. Each ev is different and proprietary. The chargers aren't even the same.

Swapping an EV battery is like swapping an ICE transmission. You can do it if you have a car lift and a scissor jack to drop it.

Sure, but one can argue that a EV could be designed/optimized for faster battery replacement. While it would still need at least a forklift to move the batteries, I believe the time needed for battery swapping could be greatly reduced with a proper design.

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

#474

Post by ascar »

ossie wrote: post #126

The unit economics around this are by no means perfect but the BIG point here that should probably be in all caps is that fact that the thermal process is displaced by the use of electricity. We could argue on what is used to generate said electricity, but that is beside the point since this innovation opens up many more possibilities than are stated here. We could also argue about the comparative cost of produced en…

>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-loss, so even using all energy generated from fossil generators would only mitigate a maximum of 50% emissions (even ignoring all other efficiency losses here). And that obviously would be stupid. That energy is generated for a purpose.

The whole point of his process is to use solar/renewable/carbonfree energy to reverse carbon emissions. It would always be more efficient to just use less electricity/energy in other situations.

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

#475

Post by KaiserPro »

worldsayshi wrote: post #448
neilwilson wrote: post #446

Earlier quoted context omitted.

"why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant? " The process uses clean electricity to reverse the CO2. I suspect here we have a timing issue. When the sun shines, the gas plant will be idle, and that's when the spare electricity is available is used to reverse the process. And the physical position - the gas plant is likely to be where the sun shi…

The co2 could be stored underground? I guess that could deal with the timing issue at least?

You'd have to separate pump and store it, when electricity is expensive.

I suspect the advantage of this system is that is doesn't need pure co2 to work

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

#476

Post by Gibbon1 »

alexeldeib wrote: post #358
dragontamer wrote: post #343

Earlier quoted context omitted.

> Pipeline compressor stations often generate 35MWth+ in waste heat, which we can use at about 20% efficiency to generate electricity. Can the waste heat be used for distillation instead? To heat up the fuel/water mix to separate the two cleanly? It would seem to me that the future of "waste heat" is to actually utilize the heat, instead of powering a relatively inefficient heat-engine. Perhaps instead of 20% efficie…

re: waste heat, I've been thinking forever that someone must capture this. I've generally assumed the economics don't work out or no one has cracked it outside of scenarios like regenerative braking. We waste so much energy that we could capture and put back to use.

> We waste so much energy that we could capture and put back to use.

The biggest current waste of energy is residential heating. We take high quality energy in the form of natural gas and fuel oil and use it to produce low quality heat.

Co-gen systems burn fuel to generate electricity and use the waste heat for heating buildings.

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

#477

Post by jacobush »

rmcginnis wrote: post #287
jacobush wrote: post #166

Earlier quoted context omitted.

Please think twice about diesel - NOX is a killer. On the other hand, I expect particle emissions to be much lower with your fuel.

Much lower particle emissions is what we expect. Also no benzene, sulfur, or aromatics. Despite diesel's drawbacks, I'd rather offer zero carbon diesel as long as people are still using it.

You are certainly aware of this, but synthetic fuel is perfect for military applications and for backup generators and such, because there is no biofouling or degradation. Also wasn't the USAF testing bio jet fuel? Your product is superior on all technical points and just as good if not better on the environment.

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

#478

Post by sara7262 »

Who is Satan and why there is evil Best video about this with proofs https://youtu.be/AWNM1-xYI5E

Funny monkey using phone in video Don't think just you can use phone See how he is searching and watching own monkey videos on phone http://bit.ly/2DS4p2R

See what happened when a lion was trying to kill man http://bit.ly/2H2zsKc

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

#479

Post by jacobush »

pcl wrote: post #180
apo wrote: post #125

Earlier quoted context omitted.

Organic feedstocks (non-fuel), although smaller isn't exactly a tiny market. Depending on how much control you have over the fixation process you might be able to tap into some high-value alcohol markets. That's the main reason I added the follow-up to the original questions. In other words, the flow of material would look like: CO2 -> polymers, drugs, and other useful solid materials There would be no [product] -> C…

I believe that as long as we have a huge worldwide oil / diesel / gasoline infrastructure in place, from transport to refining to distribution to combustion, it makes a lot of sense to build reasonably-efficient carbon-neutral mechanisms to plug into that infrastructure. In other words, for the next handful of decades, the worldwide fleet of cars, trucks, generators, boats, etc. are going to be burning carbon that co…

If I am allowed to daydream freely, a huge fusion reactor with a gasoline pipeline flowing from it, is (in my mind) a beautiful thing.
Post reply on HN