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Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

news.uic.edu

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Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#101

Post by Aelinsaar »

nhebb wrote: post #95
Animats wrote: post #35

"Nanotechnology" again. It's just surface chemistry, people. It's nice that they can do this in the lab, but as usual, the PR is excessive. "The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. Especially since UC Berkeley announced a similar breakthrough last year.[1] Wikipedia points…

> as usual, the PR is excessive I think articles that over hype lab results make it to the top of HN because there is no downvote button and flagging them doesn't seem appropriate. I wish there was a "meh" option.

Or just a "Bullshit" option.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#102

Post by taneq »

TheSpiceIsLife wrote: post #36
mchannon wrote: post #5

In addition to lack of performance numbers, they misstate the amount of sunlight hitting earth by a factor of 10- it's supposed to be 1000 W/m2, not 100.

If you look at the (random) chart I found here[1] some places in the US are getting 6 - 7 sun hours (hours of insolation) so 7000 / 24 = 291 watts / square meter / day. So using a figure of 100 is quite reasonable when you consider that lots of places don't get that much sun. 1. http://www.solarpanelsplus.com/industry-professionals/insola...

Insolation is usually given as peak power with no clouds or other shade when talking about solar panels (unless you specifically say you're talking about average power over a 24hr period). I think it's probably just a typo in the article.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#103

Post by spqr0a1 »

some_guy_there wrote: post #24
danmaz74 wrote: post #2

Key facts: > In fact, he said, the new catalyst is 1,000 times faster than noble-metal catalysts — and about 20 times cheaper. > The combination of water and the ionic liquid makes a co-catalyst that preserves the catalyst’s active sites under the harsh reduction reaction conditions, No mention of efficiency compared to photovoltaic cells.

The efficiency is around 4%, as in Figure 2 from the paper. SFE is solar-to-fuel efficiency. From the paper, " We also calculated the solar-to-fuel conversion efficiency (SFE) for our photochemical process (Fig. 2C), obtaining a value of ~4.6% limited by the maximum efficiency of the PV-a-si-3jn cell (~6.0%) (13, 20). This SFE is higher than that of the water-splitting reaction (~2.5%) previously measured using an id…

For comparison, most crop plants get 1-2% solar to biomass efficiency on the high end.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#104

Post by ars »

skriticos2 wrote: post #46
runeks wrote: post #9

This is wonderful! We're surrounded by life forms that turn water, CO2 and sunlight into energy. I figure there must be some way to harness this process. I wonder how much power a large tree takes in from its leaves. If we could interface with its root system, perhaps we could extract newly created starch, and either store it or burn it off. Image a huge concrete power plant with large trees growing out of it.

There is a simple way: 1. Plant tree 2. Wait 20 years 3. Chop tree 4. Burn tree in steam engine and generate electricity. However, that's a long time for a relatively small amount of energy (not even counting logistics losses here). Most trees are just not very efficient at converting solar energy/CO2 into fuel (wood). There are better results being looked in with algae that might result in fuel some time, but it's s…

There are WAY better plants than trees for this. Switchgass is often listed as one of the best options.

You literally just cut it down, let it dry for a bit, and throw it into the exact same plants that burn coal.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#105

Post by kevinalexbrown »

nhebb wrote: post #95
Animats wrote: post #35

"Nanotechnology" again. It's just surface chemistry, people. It's nice that they can do this in the lab, but as usual, the PR is excessive. "The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. Especially since UC Berkeley announced a similar breakthrough last year.[1] Wikipedia points…

> as usual, the PR is excessive I think articles that over hype lab results make it to the top of HN because there is no downvote button and flagging them doesn't seem appropriate. I wish there was a "meh" option.

Is it excessive? It certainly doesn't seem to be BS. It's published in a reputable journal (which doesn't make it true). It discusses several of the questions raised by Animats directly (though I wouldn't say it answers them conclusively).

I do agree that the university press release isn't going to critically evaluate the work of its own researchers. That's too bad, perhaps, but it hardly renders the original result uninteresting.

Artificial photosynthesis may be old, but the advances in this work appear aimed at overcoming precisely the problems Animats raised, like catalyst preservation and efficiency.

Put another way, just because a university gushes about the work of its faculty doesn't mean the faculty's work is crap.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#106

Post by gre »

nhebb wrote: post #95
Animats wrote: post #35

"Nanotechnology" again. It's just surface chemistry, people. It's nice that they can do this in the lab, but as usual, the PR is excessive. "The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. Especially since UC Berkeley announced a similar breakthrough last year.[1] Wikipedia points…

> as usual, the PR is excessive I think articles that over hype lab results make it to the top of HN because there is no downvote button and flagging them doesn't seem appropriate. I wish there was a "meh" option.

+5, meh.

Slashdot voting options!

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#107

Post by mchahn »

PhantomGremlin wrote: post #98
the_duke wrote: post #81

Earlier quoted context omitted.

To be fair, I never read anything about fusion being 'just around the corner'. The most optimistic estimates I know of talk about commercial viability in a 30-50 year timeframe.

To be fair, I never read anything about fusion being 'just around the corner'. We've finally gotten a little smarter about the hype. There were great expectations for fusion about 40 years ago. Here's a shady group https://en.wikipedia.org/wiki/Fusion_Energy_Foundation that used the hype to raise money: In 1977, Executive Director Morris Levitt asserted that nuclear fusion power plants could be built by 1990 if the U…

>There were great expectations for fusion about 40 years ago.

I was at the NY world's fair, I think it was 1960 (56 yrs ago). I remember walking through an exhibit that showed fusion. They had a chitload of capacitors in a bank that dumped all the power into a big electric spark. It looked impressive and sounded great. They implied fusion was almost ready.

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#109

Post by goodcanadian »

the_duke wrote: post #81
wongarsu wrote: post #71

Earlier quoted context omitted.

>"The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. They don't really say that they are cost comparable to gasoline, they just make the obvious statement that if something were as cheap as gasoline that would be a big deal. I guess hyping these advances is supposed to make it easier…

To be fair, I never read anything about fusion being 'just around the corner'. The most optimistic estimates I know of talk about commercial viability in a 30-50 year timeframe.

The most optimistic estimates I know of talk about commercial viability in a 30-50 year timeframe.

Yes, and they have been saying that for 50 years . . .

Re: Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

#110

Post by danieltillett »

semi-extrinsic wrote: post #78
ckcortright wrote: post #53

One way to make a system like this one more efficient/cost effective would be to draw the CO2 from ocean surface water which has a much higher concentration than the atmosphere, depending where you are in the world.

Flue gases with a high CO2 content are better than cheap; people will actually pay you to get rid of them. And we have a lot of them (this is kind of the problem in the first place). If you look at something like the exhaust from an oxyfuel turbine, you can get 70/30 N2/CO2 with relatively high purity. For this reason, I'm always skeptical of atmospheric capture projects. It's just got to be more efficient to capture…

Actually if the CO2 absorbent is efficient it is not much harder to capture CO2 from the atmosphere than from flue gas. The key really is the CO2 flux rate which wind provides.

The real advantage of atmosphere capture is you can do the capture where the cost is lowest, not where the CO2 is emitted.

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