
Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel - Mz
https://news.uic.edu/breakthrough-solar-cell-captures-co2-and-sunlight-produces-burnable-fuel
======
Animats
"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 out that artificial photosynthesis was first achieved in
1912, and some of the same claims were made back then. There are lots of
artificial photosynthesis projects. One of the best was in 2011, the first
"artificial leaf"[3]. It ran for 44 hours.

The usual questions apply. How efficient is this? Does the catalyst get used
up, or crud up with contaminants, and if so, how fast? What limits the life of
the system? What are the costs like? (Excessive catalyst cost has been a
problem.) Is this better than all the other groups doing similar work?

Artificial photosynthesis may be useful someday, but this probably isn't the
big breakthrough that makes it a commercial product. That may come, though.

[1] [http://newscenter.lbl.gov/2015/04/16/major-advance-in-
artifi...](http://newscenter.lbl.gov/2015/04/16/major-advance-in-artificial-
photosynthesis/) [2]
[https://en.wikipedia.org/wiki/Artificial_photosynthesis](https://en.wikipedia.org/wiki/Artificial_photosynthesis)
[3]
[https://www.acs.org/content/acs/en/pressroom/newsreleases/20...](https://www.acs.org/content/acs/en/pressroom/newsreleases/2011/march/debut-
of-the-first-practical-artificial-leaf.html)

~~~
nhebb
> 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.

~~~
Aelinsaar
Or just a "Bullshit" option.

~~~
onion2k
With the majority of articles about cutting edge science, very few HN readers
would be qualified to state whether or not it's a breakthrough or bullshit.
The option would protect HN from the bullshit, but it'd also hide the
breakthroughs that people believed too good to be true. I think that'd be an
overall drop in the quality of what we read here.

~~~
Aelinsaar
You're not wrong, but maybe on HN at least many of those people can be counted
on not to vote out of reflex, unless they do really bring something to the
table.

The other simple, sad fact is that the big breakthroughs that have some
initial traction issues stick around. Often people point to the very early
history of SR/GR, but it's worth pointing out how that turned out. When a
shocking breakthrough is actually a shocking breakthrough, it ends up
producing results that speak for themselves.

Until then, when it comes to extreme claims, so many more are just "bullshit"
than "breakthrough". Our lives are finite, so it's not wise to ignore the role
of triage in those lives.

------
OscarCunningham
From the title I thought the article was going to be a sarcastic description
of plants.

~~~
taneq
Even if it's completely inorganic, plants (or algae cultures, etc) are a
necessary comparison for anything like this, but that never seems to come up.
It's like announcing the invention of the motor car without comparing it to a
horse.

~~~
adwn
> _Even if it 's completely inorganic, plants (or algae cultures, etc) are a
> necessary comparison for anything like this, but that never seems to come
> up._

Probably that's because plants are typically only 2-3% efficient when it comes
to their use of sunlight, and then it's still a long way (energetically and
logistically) to usable fuel or electricity. Plants are really not a good
comparison benchmark here.

~~~
gregschlom
Given that we are currently using plants such as corn to make biofuel (at an
industrial level, not just in the lab), I think it's actually a very valid
comparison.

------
fernly
Can anyone comment in a knowledgeable way about the chemicals involved?

1\. tungsten diselenide

2\. an ionic fluid called ethyl-methyl-imidazolium tetrafluoroborate

Just offhand I see selenium in #1, and fluorine and boron going into #2.
There's some expense there, and some handling and exposure dangers. If you
have a lot of these cells around, are there public health dangers either in
handling or in disposing/recycling old ones?

~~~
selimthegrim
WS2 should be a relatively inert wafer/flake, the desirable property is the
so-called van Hove singularity in the electronic density of states that makes
it ideal for solar cells.

------
danmaz74
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.

~~~
some_guy_there
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 identical triple-junction photovoltaic (PV-a-
si-3jn) cell (20). "

[https://d2ufo47lrtsv5s.cloudfront.net/content/sci/353/6298/4...](https://d2ufo47lrtsv5s.cloudfront.net/content/sci/353/6298/467/F2.large.jpg)

~~~
spqr0a1
For comparison, most crop plants get 1-2% solar to biomass efficiency on the
high end.

------
tener
This development is exciting, but the complexity of the chemicals involved
looks scary. I wonder if it will impede the adoption. Anyone with the domain
expertise to comment on this?

------
runeks
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.

~~~
eloff
No, that's not likely to happen. Photosynthesis is pretty inefficient, typical
plants have a radiant energy to chemical energy conversion efficiency between
0.1% and 2%. Most commercially available solar panels have more than 10 times
this efficiency.[1]

[1] [http://physics.stackexchange.com/questions/109739/is-
plant-p...](http://physics.stackexchange.com/questions/109739/is-plant-
photosynthesis-more-efficient-than-solar-panels)

~~~
doctorpangloss
Sure, but I bet your solar panels don't manufacture and maintain themselves.

To the GP's point, the total cost of ownership of a plant that makes gasoline-
level fuel is going to be more about water and land than anything else.

But the efficiency of solar panels, considering their subsidies, the rare
minerals used in their manufacture, their delivery and their maintenance...
I'm confident it's a lot less than e.g. coal, even accounting for pollution
costs, because if it really were cheaper all-around we'd be using it
everywhere!

~~~
skriticos2
>> "don't manufacture and maintain themselves"

Well, for any kind of industrial operation you'll want to plant the trees..
then there is the 10-20 year growth period that's kind of a problem for
planning flexibility.. and then you need to chop them down and move them to
the power plant which is a non-trivial and costly logistical constraint.

All the while the solar cell sits there and produces energy without any
intervention. That's a big difference.. Also, wood does not scale well, there
is just so much space for forests.

~~~
dredmorbius
Solar cells don't _just_ sit there without intervention, and have larger up-
front capital and labour costs than planting an orchard, or more
appropriately, fuelwood or timber forests. And have a lifespan of 20-25 years.

Plants are a pretty neat technology, all told.

~~~
maerF0x0
I dont know how much they differ but planting trees has lots of cost. I
estimate the cost of planting is something like $3 per surviving tree. (Cause
you usually over plant assuming many will die).

~~~
dredmorbius
Depends on the tree.

For some forestry applications, seeding is done from the air.

Note that if you're growing wood for fuel, you're not worried about grafting
stock, or the net health (much), or overcrowding (you can thin later if
necessary), etc.

Planting _orchards_ is, as it happens, pretty expensive. But that's also a
pretty high-end case, and the expected life is generally 20-50+ years. Upwards
of 300 in cases (olives, grapes, and citrus).

~~~
maerF0x0
I was not referring to orchards, but for regular logging industry. Those
cycles are about 60-80 yrs between harvests.

------
ivan_ah
paper:
[http://science.sciencemag.org/content/353/6298/467](http://science.sciencemag.org/content/353/6298/467)
(paywall), but it's available on sci-hub.cc

~~~
Mizza
[http://science.sciencemag.org.sci-
hub.cc/content/353/6298/46...](http://science.sciencemag.org.sci-
hub.cc/content/353/6298/467)

------
ckcortright
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.

~~~
semi-extrinsic
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 from a mixture with 20% (or more) CO2
than from a mixture with 0.04%.

~~~
danieltillett
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.

~~~
semi-extrinsic
> The key really is the CO2 flux rate which wind provides.

Indeed. This brings us to the issue of volumes. A useful carbon capture plant
needs to capture at least 100 000 tons of CO2 per year (then we need "just" ~
10 000 such plants). This means each of these minimal plants has to process an
air volume of 250 billion cubic meters of air per year. At an air speed of 1
m/s (you can't flow too fast or there is no time for reaction), and assuming a
wildly optimistic 50% capture from the filtered air, you need a reaction area
of over 15 000 square meters.

Mind you, that's the area of the membrane which processes air. Add the
auxiliary stuff around it, you can add at least another factor of 100 to the
area, so each of your 10 000 plants have to be 1.5x the maximum planned size
of the Tesla Gigafactory. And we're being optimistic.

~~~
ytpete
Couldn't the membrane be folded or stacked so you achieve that amount of
surface area in a far smaller floorplan footprint?

~~~
semi-extrinsic
If I understand it correctly, all the membrane area has to be exposed to
direct sunlight.

------
loeg
So it's 20x cheaper than the noble gas version — what's the absolute cost? I
assume it's not cheaper than pumping fossil fuels yet, but I'm curious to know
how far away it is.

~~~
willvarfar
Yeah, this sentence in the middle of the article:

> The ability to turn CO2 into fuel at a cost comparable to a gallon of
> gasoline would render fossil fuels obsolete.

Doesn't actually say that this _is_ at a cost comparable to a gallon of
gasoline :)

Sly words.

~~~
loeg
It would be pretty shocking if it was already cost comparable, of course :-).

~~~
Dylan16807
Sure, but there is a big gap between "we can see a path to getting there with
mass production" and "sure would be nice, wink"

------
mchannon
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.

~~~
TheSpiceIsLife
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...](http://www.solarpanelsplus.com/industry-
professionals/insolation-charts/)

~~~
taneq
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.

------
vonnik
Isn't it counterproductive to turn it into fuel to be burned? It seems like
that would leave us at best at no net new carbon dioxide, when we really
should be sucking CO2 out and sequestering it away. How about we turn it into
bricks or something...

~~~
neltnerb
It's counterproductive in the sense that you'd be guaranteed to reduce carbon
emissions more (globally) if you were to instead just not burn fossil fuels at
all. If you took the solar cell part and just used that electricity to
displace carbon fueled power plants, you'd end up ahead.

That said, for a little while at least, having liquid fuels is inherently
given a bonus relative to electricity only. Of course, you can just make those
from the original fossil fuel sources as well...

Honestly it seems like a bit of a mess since each team solving problems
locally rarely has all the expertise needed to see the impact globally. I
certainly don't, though I've been studying it for many years.

I very much appreciate that things like the CA-GREET models have been trying
hard to make it easier to apply wide systems analysis expertise to understand
a small part of the overall system without spending years doing the math. But
probably it will end up needing to be solved by AlphaGo...

------
sdenton4
Interesting that it's a combination of hydrogen and carbon monoxide that it
produces. Wonder what the safety implications are.

~~~
twic
As it says in the article:

"the artificial leaf delivers syngas, or synthesis gas, a mixture of hydrogen
gas and carbon monoxide. Syngas can be burned directly, or converted into
diesel or other hydrocarbon fuels."

Hydrogen and carbon dioxide are the feedstocks for the Fischer-Tropsch
process, which produces conventional hydrocarbon fuel:

[https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces...](https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process)

In other words, H2 and CO are _exactly_ what you want!

~~~
evgen
Probably also worth noting that syngas is the primary input for the Haber-
Bosch method used to generate the ammonia feedstock for most of our synthetic
fertilizers. If you just take the CO and pump it underground then you are
actually producing fertilizer for agriculture using a carbon negative process.

~~~
HillaryBriss
> ... take the CO and pump it underground then you are actually producing
> fertilizer for agriculture

Interesting. How does the CO fertilize the plants?

~~~
efng
I assume he meant carbon sequestration.

~~~
evgen
Yes, my prose was a bit less clear than I had intended. You can oxidize the CO
and be carbon neutral or sequester it and be carbon negative.

------
gravypod
I'd love to see how this would work in my use case. I enjoy brewing alcohol
and if I could capture and tap into that with a system like this I'd probably
get a better yield then the average user.

It would be cool.

------
kelvin0
Another interesting concept from Daniel Nocera a few years ago (Sun
Catalytix), seemed to be full of promise as this one.

[http://www.forbes.com/sites/michaelkanellos/2014/08/26/mit-c...](http://www.forbes.com/sites/michaelkanellos/2014/08/26/mit-
curse-part-ii-lockheed-martin-scoops-up-sun-catalytix/#287da5446da8)

It looks like these great promises never quite reach the level where they can
get to market and create the impact they claim. Trust me, I really wish it
were different, and I root for each and evey one of them to succeed. Maybe
military and big corp. snatch the tech before they reach consumers (most
likely).

------
sidcool
This is good finding, but anything substantial will take some time to
materialize. But good we are trying to find ways to suck the excess CO2 from
the atmosphere.

------
B1FF_PSUVM
One of these days, some cleverclogs is going to present to the press a black
box that stores electrical charge (and even gives back almost all of it when
asked politely) with an energy density almost as good as liquid fuels.

If he can shut up about it containing liquid fuels that are synthesized on the
spot, they'll eat it up and hail the finding of the battery holy grail.

------
Quequau
I think what would make for a larger breakthrough is a process which produced
a replacement of cement aggregates from air or sea water at gigantic
industrial scales.

------
calebm
I wonder what the effeicency is compared to growing and burning trees (which
of course, also capture CO2 and sunlight and turn them into burnable fuel).

------
retox
I don't want to poo-poo this achievement, but is another burnable fuel really
what we want at this point?

~~~
eloff
I'm going to say yes, very much so.

Remember the carbon here is coming from the atmosphere, so it's carbon neutral
and won't contribute to climate change.

If the process can be scaled up to produce a gallon of gasoline for less than
the costs of extracting crude from the ground and refining it - then it will
quickly kill off new investment into the fossil fuel extraction industry. As
opposed to alternate energy technologies, like electric cars which will take a
long time to replace internal combustion engine cars. It would use all of the
existing infrastructure, so all it has to be is cheaper for market forces to
work their magic.

That's a very big IF, however, so don't get your hopes up.

------
ryanmarsh
I can think of another way you can take sunlight and CO2 and produce a
burnable fuel...

------
Ultimatt
You mean growing trees for wood fuel...

------
T2_t2
> Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

Is it called "A Tree"? Those things are ancient!

------
known
Is it scalable to drive a Car?

------
67726e
Add unsweetened shebenchnach. C

------
nether
How many times per year do we see this? I'll give a shit when I can buy a
panel of these cells off Amazon.

------
johnchristopher
More `burnable fuel` doesn't seem to be part of any answers to climatic change
though.(haven't read the whole article yet)

------
sevenless
> Authors: Mohammad Asadi, Kibum Kim, Cong Liu, Aditya Venkata Addepalli,
> Pedram Abbasi, Poya Yasaei, Patrick Phillips, Amirhossein Behranginia, José
> M. Cerrato, Richard Haasch, Peter Zapol, Bijandra Kumar, Robert F. Klie,
> Jeremiah Abiade, Larry A. Curtiss, Amin Salehi-Khojin

I wonder how many of the scientists who made this discovery would be banned
from entering the United States by Donald Trump and the Republican Party.

~~~
jrapdx3
Don't know of course, though it appears to be a "diverse" group who worked on
the project. The salient point is Trump has made it clear he was talking about
_illegal_ entrants and _delaying_ entry for individuals coming from areas
where terrorism is endemic, until a vetting process is established. There are
a great number of professionals from Muslim countries regularly admitted who
contribute to American society and culture and that would not change.

~~~
CoryG89
> and delaying entry for individuals coming from areas where terrorism is
> endemic, until a vetting process is established.

I hate to even further the discussion on this off-topic subject, but the above
is simply not true. Here is the official statement (still published in it's
original form) directly from Donald Trump's website:

> Donald J. Trump is calling for a total and complete shutdown of Muslims
> entering the United States until our country's representatives can figure
> out what is going on.

This is a far cry from "individuals coming from areas where terrorism is
endemic". Regardless of your stance on politics, what that statement suggests
is blanket discrimination based on religious belief.

[https://www.donaldjtrump.com/press-
releases/donald-j.-trump-...](https://www.donaldjtrump.com/press-
releases/donald-j.-trump-statement-on-preventing-muslim-immigration)

~~~
jrapdx3
Well, it appears to be policy in evolution. I based my comment on what Trump
has said in his most recent appearances, and quite credibly that's not yet
reflected in the online published material.

Realistically campaigns of all stripes frequently change positions and policy
is hardly set in stone. I expect we'll witness numerous "corrections" from all
candidates as the election season moves along.

BTW during the Republican and Democrat conventions just concluded, both
candidates mentioned policies of this kind. It might be worth the effort to
listen to both party's candidates' acceptance speeches since that would
represent their current positions.

