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

Engineers are developing new ways to convert greenhouse gases to fuel

uc.edu

Post reply on HN
Print view View original

101–110 of 213 posts

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#101

Post by yholio »

eightysixfour wrote: post #34
yholio wrote: post #15

No, enough with this nonsense. Capturing, liquefying and transforming CO2 into fuel requires energy - due to thermodynamic limits, much more energy than what the fuel can give back. You then take that fuel, and... burn it into 25% efficient engines that spew the very same CO2 back into the air, along with some new carcinogenic fumes and acid-rain inducing nitrogen oxides? No, just no, full stop. They way forward is e…

I was with you until no hydrogen. While it is inefficient in compared to batteries, as long as it is being produced with carbon-neutral energy then there are areas where its kWh/kg ratio and comparatively rapid refilling are extremely beneficial.

You should take that kWh/kg figure with a kg of salt. You need a heavy COPV tank to store hydrogen under pressure, a 100 kg tank might store only a few kg of fuel, take 400 liter to do so, and be comparable with a 30l conventional fuel tank: https://www.fsec.ucf.edu/en/consumer/hydrogen/basics/documen...

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#102

Post by ncmncm »

rale00 wrote: post #76
eganist wrote: post #10

I'm less interested in this as a climate change remedy (it's not) and more interested in this for its terraforming potential. What are the benefits and risks from just bleeding spare methane into the atmosphere after any refueling reservoirs are topped off? I'd think it'd be useful in raising temperatures on the planet, though that's only one terraforming component. (I'm very dangerously not an expert on this)

Methane is fairly short-lived in the atmosphere, at only 12 years, so it probably wouldn't be particularly effective at terraforming mars. Perfluorocarbons or sulfur hexafluoride can stick around for thousands of years, so they would probably be a better place to start.

Current SF6 level (four orders of magnitude more heat-trapping than CO2, by weight) accounts for 10% of heat forcing. How the heck do we get that stuff out of the atmosphere?

There is a replacement, now, for SF6, for use in power stations and wind turbines. Now the SF6 in use needs to be pumped out and disposed of safely, and SF6 actually banned. And, we have to persuade China to replace theirs too.

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#103

Post by thinkling »

tito wrote: post #57

For anyone starting a carbon removal startup, check out AirMiners http://airminers.org For anyone who has been scouring the web to learn about carbon removal and wants all the best stuff in one place, check out the 5-week AirMiners Boot Up http://bootup.airminers.org

Super interesting, thanks! Any idea what the timeline will be on your fund?

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#104

Post by yholio »

colordrops wrote: post #79
mrguyorama wrote: post #65

Earlier quoted context omitted.

It would take more time, energy, money, and resources to build out enough solar and wind (etc) to turn enough CO2 into enough fuel for all our cars than it takes to just replace the cars with electric ones and use that massive solar and wind grid to just power them straight

It's not all or nothing, and further more the electricity from solar and wind is fungible and can be used for either fuel generation or direct usage by electric cars, so it would serve us either way, no matter how long it took. These things are not contradictory. We can build out more renewable electricity supply, replace with electric cars, and generate carbon neutral fuel all at the same time. You are underestimati…

In Europe, fosil fuel engines are already 2-4 times more expensive to run than electrics. In 11 years, which is the average age of a car in Europe, the majority of private vehicles will switch naturally for purely economic reasons. In 20 years, the same will be true for busses, trucks & tractors.

And it will be driven solely by better economics.

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#105

Post by ncmncm »

lmilcin wrote: post #99

Don't get your hopes too high if you think this can be used to scrub significant amount of CO2 from atmosphere. Don't get me wrong, producing fuel from atmospheric CO2 is still wonderful news. But you know what they produce? Methane. And methane is what? It is A FUEL . And what we do with fuel? We BURN it. Once you burn methane you get the CO2 back, for net ZERO effect on the atmosphere. The only way this works to he…

24 times more.

You are better off just pumping the CO2 down there, instead, and arranging for it to turn into rock.

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#106

Post by yholio »

_Microft wrote: post #27
yholio wrote: post #15

No, enough with this nonsense. Capturing, liquefying and transforming CO2 into fuel requires energy - due to thermodynamic limits, much more energy than what the fuel can give back. You then take that fuel, and... burn it into 25% efficient engines that spew the very same CO2 back into the air, along with some new carcinogenic fumes and acid-rain inducing nitrogen oxides? No, just no, full stop. They way forward is e…

It can make sort of sense for applications for which the energy density of the fuel (like for airplanes or rockets) matters a lot. The energy density of current generation lithium ion batteries is insufficient to allow for long-range flights. Synthetic fuels could allow planes to still travel around the world while being effectively net zero emitters because the CO_2 was harvested from the atmosphere (or another, una…

There is already a good solution for planes: ammonia, manufactured efficiently from green hydrogen. You will never be able to use gaseous or liquid hydrogen on planes due to the high volume, weight and risk associated with known storage methods.

Ammonia seems to strike the right balance: https://www.ammoniaenergy.org/articles/zero-emission-aircraf...

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#107

Post by twostorytower »

perfunctory wrote: post #91

On the side note, anybody knows what happened to the prometheus startup [0]? Are they still alive? [0] https://news.ycombinator.com/item?id=19842240

Looks like they're still alive and well: https://prometheusfuels.com/technology

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#109

Post by fozzyfozfoz »

throwaway894345 wrote: post #2

The actual title is "UC reactor makes Martian fuel" and the subtitle is "A gas station on Mars? Engineers envision the possibilities." But the submission title is "UC reactor converts carbon dioxide to fuel to address climate change"? While it does talk about applications with respect to carbon capture, if we consume the fuel byproduct, presumably we just end up with co2 in the atmosphere? > “In the future we’ll deve…

Yea that CO2 is not as easy to pump as sticking a drill in some oil plump wet dirt and pumping away.

Re: Engineers are developing new ways to convert greenhouse gases to fuel

#110

Post by fnord77 »

robbrown451 wrote: post #108

Title on HN should probably read "University of Cincinnati" rather than UC. Even I, a graduate of University of Cincinnati now first thought "University of California." (Admittedly I live in California now)

I'm impressed that University of Cincinnati snagged uc.edu
Post reply on HN