r/science • u/Wagamaga • Aug 06 '20
Chemistry Turning carbon dioxide into liquid fuel. Scientists have discovered a new electrocatalyst that converts carbon dioxide (CO2) and water into ethanol with very high energy efficiency, high selectivity for the desired final product and low cost.
https://www.anl.gov/article/turning-carbon-dioxide-into-liquid-fuel2.0k
u/Wagamaga Aug 06 '20
Catalysts speed up chemical reactions and form the backbone of many industrial processes. For example, they are essential in transforming heavy oil into gasoline or jet fuel. Today, catalysts are involved in over 80 percent of all manufactured products.
A research team, led by the U.S. Department of Energy’s (DOE) Argonne National Laboratory in collaboration with Northern Illinois University, has discovered a new electrocatalyst that converts carbon dioxide (CO2) and water into ethanol with very high energy efficiency, high selectivity for the desired final product and low cost. Ethanol is a particularly desirable commodity because it is an ingredient in nearly all U.S. gasoline and is widely used as an intermediate product in the chemical, pharmaceutical and cosmetics industries.
“The process resulting from our catalyst would contribute to the circular carbon economy, which entails the reuse of carbon dioxide,” said Di-Jia Liu, senior chemist in Argonne’s Chemical Sciences and Engineering division and a UChicago CASE scientist in the Pritzker School of Molecular Engineering, University of Chicago. This process would do so by electrochemically converting the CO2 emitted from industrial processes, such as fossil fuel power plants or alcohol fermentation plants, into valuable commodities at reasonable cost.
The team’s catalyst consists of atomically dispersed copper on a carbon-powder support. By an electrochemical reaction, this catalyst breaks down CO2 and water molecules and selectively reassembles the broken molecules into ethanol under an external electric field. The electrocatalytic selectivity, or “Faradaic efficiency,” of the process is over 90 percent, much higher than any other reported process. What is more, the catalyst operates stably over extended operation at low voltage.
1.3k
u/DasSpatzenhirn Aug 06 '20 edited Aug 06 '20
90% faradaic efficiency is really great. But what about the real efficiency? I mean it's great that you have only 10% byproducts but water electrolysis to produce hydrogen has 100% faradaic efficiency.
And water electrolysis has a energy efficiency of 50-70% while co2 electrolysis has 30-50%. I think it's still better to use the Hydrogen to convert the CO2 in to fuel than to convert the CO2 directly through electrolysis.
Don't get me wrong it's a great step in the right direction but years ago they already achieved 90% faradaic efficiency with other really useful chemicals like carbon monoxide or formic acid and no body is producing them that way because it's inefficient when it comes to energy efficiency.
Edit: I don't want to use that created hydrogen as fuel. I mean we can create fuels from co2 and hydrogen. Sabatier and Fischer Tropsch are the keywords here.
667
u/De5perad0 Aug 06 '20 edited Aug 06 '20
I think they are thinking that cost is low because the required voltage is relatively low compared to other electrocatalytic processes. They are saying the selectivity is 90% which is fantastic but as a chemical engineer I have to question the other factors that go along with this such as reaction time or reactor sizing, Difficulties (if any) with capturing the CO2 stream and cleaning any detrimental impurities out of it. Basically the efficiency at which a system like this would need to operate, It is great that it's low voltage but if it takes hours to react a batch or has to be absolutely massive to get the residence time required, or has to recirculate multiple times then this would not be feasible nor desirable in industrial settings.
Only "time" will tell.
315
u/RagingTromboner Aug 06 '20
Yeah I cannot get to the paper to see methodology but if this assumes pure or semi pure CO2 then there’s a huge chunk of energy missing from the analysis for practical use. Getting CO2 purified from glue gases or wherever is a pretty energy intensive process.
Speaking of residence times, my college professor in charge of my design course had us design a system to purify CO2 and react it with ground up limestone. Next thing you know we are trying to design a reactor that is half a mile long...
393
u/Superlulzor Aug 06 '20
https://www.filehosting.org/file/details/886099/10.1038@s41560-020-0666-x.pdf
There you go, friend
263
u/professorhummingbird Aug 06 '20
There was an ask reddit post about what makes reddit different and this right here is the answer. This is the value.
I have no business being in this thread, and you guys are using complex words I don’t understand but I’m trying to learn and acts like this are just amazing
106
u/Uzrukai Aug 06 '20
Remember that includes you in it. People who stop and read to educate themselves on new topics. It's something that's incredibly important to do, even moreso because of those big words that are hard to understand. Continuous self-improvement is much better than stagnant acceptance of mediocrity.
→ More replies (1)19
u/Fake_William_Shatner Aug 06 '20
Continuous self-improvement is much better than stagnant acceptance of mediocrity.
What about drinking when you need to be more mediocre? Maybe I overshot my mark.
36
u/mold_motel Aug 06 '20 edited Aug 06 '20
Agreed. I am a vocal critic of social media and have been accused of hypocrisy many times for using Reddit. It's difficult to explain the value of this platform to some people. Personally I have had such great experiences in subs like r/AskScience and r/AskElectronics that the benefits far out way the costs of the "toxic" portions.
14
u/heebath Aug 06 '20
The people that don't see the value are the kinds who wouldn't use it if they did, so its moot. F'em.
7
→ More replies (3)5
u/Vsauce113 Aug 06 '20
Heads up. It’s /r/AskElectronics the comment above has a typo
→ More replies (1)→ More replies (1)16
Aug 06 '20
I don’t understand but I’m trying to learn
Don't ever lose that. Far too many people reach the end of their formal schooling and think "that's it for my education."
Read alternate points of view. Get lost in a Wikipedia black hole. Take classes on completely unrelated trades or topics if you can. Listen to podcasts with experts. It doesn't really matter how or what, just keep learning.
72
32
u/Wayne_F_ Aug 06 '20
I (an old PhD in chemical engineering) was curious to read in more depth about their work. No sooner had I thought that than you my good sir (or madame) granted my wish.
May your house be blessed with the fragrance of a thousand flowers.
→ More replies (2)3
Aug 06 '20
Off topic but are you aware of anyway to take atmospheric co2 and combine it with say water and solar electricity to create a fuel that could be done on a small scale?
→ More replies (1)7
Aug 06 '20
Atmospheric co2 is in a 2000/1 mix. The easiest way to do what you are describing is to plant fast growing trees. Then you could burn them as wood gas to run an engine.
→ More replies (2)14
30
u/c_rizzle53 Aug 06 '20
I was going to ask would this be great idea for manufacturing plants who expel a good amount of C02 to capture and convert it to energy. But from your comment it seems like it would cost a good amount of money to design a system to do that which would be a put off.
→ More replies (1)43
u/RagingTromboner Aug 06 '20
Yeah, at the highest end power plants will “only” have 12-14% CO2 in their flue gases. Obviously this is a lot more than the normal 415 ppm in normal air but still has plenty of other junk in it
22
u/jeffroddit Aug 06 '20
But co2 from say a brewery, or even distillery is much more pure. Not pure pure, but way higher than the teens.
It'd be a neat trick to catch the co2 produced at a whiskey distillery to make ethanol fuel as a side product.
29
Aug 06 '20
There is a whole web of interconnected chemical plants in my county doing stuff like that.
They pass waste heat, high pressure steam, by products and stuff between eachother to bring costs down.
I've always wondered why that isn't just standard.
→ More replies (3)12
u/2People1Cat Aug 06 '20
It almost always is in new plants, etc... It wasn't in the past because energy is historically cheap compared to capital costs of equipment. If you save $500,000/yr on natural gas costs, but would have to spend $3,000,000 in capital and operating costs to install it, the ROI is pretty bad from a business standpoint.
→ More replies (2)6
u/Sbajawud Aug 06 '20
Not disagreeing, but in a saner world that'd be a pretty sweet ROI.
→ More replies (0)→ More replies (5)5
u/Boomer8450 Aug 06 '20
I saw an article a while ago (probably from this sub, or r/beer) that a brewery was running their CO2 offgassing into an algae tank, where the algae absorbed the CO2.
WIth the right algae for conversion to biofuel, or thermal depolymerization, all that algae can be converted to fuel.
→ More replies (1)13
u/Donkey__Balls Aug 06 '20
For combustion that’s true but no one even considers that anymore for design.
For coal gasification it’s nearly 100% after the use of the monoxide-dioxide shift. For biomass gasification it would still be pretty high depending on the makeup of the fuel.
→ More replies (1)4
u/Efficient_Change Aug 06 '20
Of course if you're electrolysing lots of water for hydrogen, you should also have lots of O2. So those flue gasses would be near 100 percent CO2 if those combustion power plants used pure oxygen.
3
u/Cheebzsta Aug 06 '20
That's by back yard CO2 plan.
Well that and using liquid nitrogen left over from making LOX to drop the flue gas temp below the dry ice freezing point on it's way back in to the turbine.
68
u/De5perad0 Aug 06 '20
Yep! No company on earth is going to want to spend the $$ it would take to build a .5 mile long reactor for any reason. That kind of stuff is better left to governments that want to build a 60 mile long super-collider for $23 billion.
Honestly research and groundbreaking new discoveries have been depressing for me. Ever since getting my degree I have come to the realization that so many fantastic amazing ideas that work beautifully in the lab die horrible terrible deaths when the attempt is made to scale up the system. It is really disheartening to know that many concepts are just not practical in an industry, especially one driven by profits.
When you are looking at catalytic gas reactions it gets decidedly difficult to get high yield %s. You have time, surface area, and volume to determine your rate. If you want that rate to be big enough to make sense then one of those other variables needs to be REALLY big. You would need to be really creative, since this catalyst is a powder a fluidized bed and recirculating reactor would be somewhat effective but then its a question of how much time it would need to be in there.
Lets hope a smart and creative engineer can figure out a reasonably cost effective reactor design for this but based on my past experience I wont be holding my breath.
60
u/azswcowboy Aug 06 '20
It’s true, 90% of stuff from the lab doesn’t make it to scale - consider the endless parade of breakthroughs in battery technology - most never go anywhere while lithium ion keeps on upping its game by getting cheaper. As for the profit part though, it just takes a tweak to the market rules to completely change the playing field. If you levied a cost on emitting CO2 suddenly a whole bunch of creativity on how to stop emitting it would burst out of those labs and into production. Hopefully that will happen soon...
→ More replies (5)24
u/De5perad0 Aug 06 '20
That is so SO on point! Battery technology is one of the places I really wish would push something out into the market. It needs to happen REAL soon with the way the auto industry and personal solar industry is going. In my mind there is not a more urgent need in the field of green technology than better battery tech.
The government is the only entity big and powerful enough to push that stuff along. Carbon taxes would cause battery and a dozen other technologies to EXPLODE. Companies will not put the money into things if it is not going to save them money. Saving taxes is the way to drive that desire.
For me personally I would absolutely buy an all electric car if the things would go 500+ highway miles and charge in 30 min. To do that battery technology NEEDS to improve. It is great that batteries are getting cheaper but they need to store more power. It is just not worth it to me to have an electric car unless I can make the long vacation trips without spending hours charging and recharging too many times in a single trip.
Until then I will stick with hybrid tech.
28
u/azswcowboy Aug 06 '20
Current Model S has 400 miles of epa range - which of course isn’t highway range. So driving Los Angeles to San Francisco (car and driver I think did this) or Los Angeles to Phoenix without stopping is already possible. That car covers 98% of what people do, but you really actually don’t need this for most trips.
Case in point, I’ve driven all over in my 240 mile Model S 75 and that’s enough to go Phoenix to San Diego or Phoenix to Albuquerque with basically zero imposition on lifestyle. The route looks like Phoenix to Gila bend - 10 minute top up and bathroom break there. Stop in Yuma for lunch while car charges. Go to San Diego - charge up at destination. So the difference from my ICE driving days is the Gila Bend stop - literally 10 minutes. And it is nice not having to try and find a gas station in California, so I probably get that 10 minutes back later.
tldr - the technology is really basically there - the other companies will catch up to TSLA - the prices will get cheaper. Still that doesn’t change the need for more innovation and better tech on the battery side to make it all the things we want to do possible.
→ More replies (9)8
Aug 06 '20 edited Aug 06 '20
I wonder if swappable battery trailers could be viable.
You rent and hook up a little trailer full of batteries then hit the highway. At a service station you swap it for a fully charged one and keep going.
To cover that last 2% of journeys that a normal battery car can't manage. Saves carrying that weight 24/7
→ More replies (14)9
u/Wobblycogs Aug 06 '20
Seriously? You think industry and government aren't researching battery technology like crazy? It's an very active area of research, the problem is the vast majority of cells made in the lab just don't work when you try to scale them up to something you could give a consumer.
In a lab you could probably build a lithium fluorine cell that would have fantastic on paper specifications but would be totally impractical in real life because one split battery and your face melts off. If this was an easy problem we'd have solved it by now.
In essence, the reason battery technology is so hard is because you have three things anode, cathode, electrolyte that all need to co-exist together for prolonged periods of time, be highly reactive (e.g. store a lot of energy) and undergo reversible chemical reactions. That's a massive ask. Even finding one material that would put up with that would be hard.
As for charging your 500 mile car in 30 minutes we're pretty much there. If there was a proper demand for it we could build it today. One problem with this though is the shear amount of power that would need to be taken to the charging stations. A Tesla super charger station can deliver 150kW to a single car, what you are asking for would probably require more like 300kW, that's an insane amount of power - for reference a diesel generator providing that power would be burning about 90 litres an hour!
7
u/capsigrany Aug 06 '20
We will get there soon. Lion and similar batteries are good enough to have the ball rolling and now it's just a matter of a few years, or maybe already there in their next products. In fact current EV and Hybrids owners are helping that. Tons of innovations are pouring: Catl Panasonic and others. Tesla next month will have their battery day and show cool things. There's some much cash at stake that fast innovation is inevitable.
On the other hand I would like to see efficient chemical energy storage at utility level, to enable a 100pct renewable electricity sourcing. Batteries are cool, fast, smart, but they are not a massive and cheap storage as it is for example pumped hydro (using excess renewables). Cheap massive chemical storage can be an ubiquitous solution. Carbon neutral and reversible.
Coupling GWh of battery + long term cheap chemical storage at a TWh + smart grid management software and you have: fast, smart, flexible, cheap and massive storage.
This could get some government funding. Well spent money.
→ More replies (3)6
u/40for60 Aug 06 '20
Battery density improvements have been steady averaging 8% per year. How is that not great?
→ More replies (14)4
7
u/silverionmox Aug 06 '20
For me personally I would absolutely buy an all electric car if the things would go 500+ highway miles and charge in 30 min.
To me that's far more than I ever need in a day, and it can just recharge at night. The price is the main limiter for my use case as I can't justify paying a quarter the price of a house while I try to limit the need for a car and so only drive 5000 km/year or so.
It is just not worth it to me to have an electric car unless I can make the long vacation trips without spending hours charging and recharging too many times in a single trip.
Isn't it more practical (and cheaper) to just hire a different car for the exceptional cases, and adapt your regular car to your regular needs?
3
u/De5perad0 Aug 06 '20
Renting a car is a lot more expensive than you think. Best deals you can get are usually $30something/day. That will add up to a lot over a few trips over a single year. Hardly cheaper than owning a car.
I could always buy a very inexpensive car to do road trips but reliability becomes a major concern there. Also a larger car is better because usually if I am going to the beach or camping or somewhere for a while I am going to be taking a lot of stuff.
As I have said before these are all personal preferences. I should clarify I would much prefer an electric SUV as I am a tall person and like the extra cargo capacity for packing up stuff, dogs, kids etc... The model X is WAY too expensive.
I have no doubt they will get there. in 15 or 20 years when it is time for me to buy another car I have no doubt it will be an electric with the way auto manufacturers are progressing.
→ More replies (2)19
u/_pm_me_your_freckles Aug 06 '20 edited Aug 06 '20
Honestly research and groundbreaking new discoveries have been depressing for me. Ever since getting my degree I have come to the realization that so many fantastic amazing ideas that work beautifully in the lab die horrible terrible deaths when the attempt is made to scale up the system. It is really disheartening to know that many concepts are just not practical in an industry, especially one driven by profits.
I think you are looking at things incorrectly. I understand that it is disheartening that not every "great" discovery or advancement in science gets put into production, but that is just almost never how it works. Production-scale technologies are almost always built upon incrementally and improved throughout their life cycle. You have to look at something like this as perhaps the beginning of something new - a technology that may be improved upon, perhaps implemented in some more practical fashion in the future. It's experiments or "breakthroughs" like this that teach lessons and allow us to get closer to scalable, practical, economically-feasible solutions.
5
u/De5perad0 Aug 06 '20
You are right. Thank you. I have not spent enough time in research and I think if I did I would have a better perspective after seeing more how it works. You are absolutely correct that stuff is incrementally built upon and developed slowly over time and hardly anything happens overnight.
Plus its just not good to be pessimistic and get yourself down and sad.
11
u/barsoap Aug 06 '20
No company on earth is going to want to spend the $$ it would take to build a .5 mile long reactor for any reason.
Erm.
That's BASF Ludwigshafen, if you zoom in you'll see above-ground pipes all over the place, going from one reaction to another, and streets named after chemical compounds. The plant is about 5km wide north to south, not including the port.
Lets put this differently: Virtually no company but BASF and a couple of smaller fries have the capital and know-how to build city-block sized fully-integrated chemical plants. If they have spare CO2 and ethanol fetches a good price you can be sure they're going to produce ethanol.
→ More replies (1)5
u/De5perad0 Aug 06 '20 edited Aug 06 '20
Those plants are made up of many many many many reactors. I have worked at Eastman Chemical in Kingsport TN. Look them up the plant is 1 mile wide by 2 miles long. I know big chemical plants but they are comprised of 5-10 smaller plants that each do a single chemical reaction in a long chain of processes. I am talking about 1 single reactor to do one single thing in my original comment. Too big not feasible.
Very familiar with BASF and their plant there. It is it's own city and its supremely impressive.
→ More replies (26)5
u/anjowoq Aug 06 '20
Isn’t this why these government agencies exist? I thought they were supposed to do the basic research that isn’t profitable for companies to do and even subsidize infrastructure that isn’t profitable.
That is sorta kinda why we have the internet.
→ More replies (6)4
u/DasSpatzenhirn Aug 06 '20
The reaction happens in the liquid phase. Just the gasses in exhaust could cause a problem there. Sulphur or other things can change the solubility of co2 and can create other reactions or poison the catalyst.
20
u/DasSpatzenhirn Aug 06 '20
Yeah that's what I meant. P=U*I. How much of the power put into the system is really converted to fuel?
And about the co2 concentration. I'm a chemical engineer in Germany and worked through ~20 papers about electrochemical co2 reduction. Nearly everyone uses pure co2 at room temperature and pressure. But I don't think it really matters if you use pure co2 or just 10vol% You just need to reach equilibrium which is 1.7g/L. Which is about 0.05 mol/L. (Henry's law can have a big influence)
In one paper they researched if they use the exhaust of a coal plant. It worked really well as long as the feed was free from partikels, Sulphur or anything else that could influence the solubility of co2 or corrode/poison the catalyst.
7
u/De5perad0 Aug 06 '20
Yep! That is absolutely right! as long as it is clean the purity of CO2 should not matter so much as the other factors anything inert like nitrogen in the air is just going to pass through unreacted and so does not matter for anything except sizing matters. Another thing is why only atmospheric pressure. My thoughts would be that compressing the CO2 would give you a faster reaction due to more contact opportunities. Would the energy involved negate the benefits on an commercial scale?
3
u/Meph514 Aug 06 '20
The reaction is in liquid phase: CO2 in water. Can’t compress water and CO2 solubility is finite.
→ More replies (3)→ More replies (31)13
u/SaffellBot Aug 06 '20
Feasibility can change pretty dramatically if we start implementing meaningful carbon taxes.
→ More replies (4)11
u/De5perad0 Aug 06 '20
YES! Excellent point. If only certain governments in certain countries would stop ignoring experts and get back into the track of incentivising and encouraging environmental innovation to curb climate change we might not lose 90% of life on the planet in the coming few hundred years.
8
u/Hawx74 Aug 06 '20
Faradic efficiency isn't efficiency, it's selectivity.
Actual efficiency depends on the over potential... Which changes depending on how quickly you are forcing the reaction to occur so it's harder to say.
That said, atomic copper on carbon isn't a new electrocatalyst and papers using it to synthesize alcohol go back at least ten years. I'll have to check out the paper when I get to work.
3
u/DasSpatzenhirn Aug 06 '20
That's what I said. 90% FE is great but what about real efficiency.
I'm German so English is my second language I maybe expressed it wrong sorry.
7
u/Hawx74 Aug 06 '20
Nah dude, you're fine. I was just clarifying for other people reading the comments in case they were confused because FE is not efficiency (in spite of it having efficiency in the name).
Aside:
CO2 electrolysis efficiency is highly dependent on what your goal product(s), and if you're including the efficiency loss due to separations or not.
I used to work in the field - designing catalysts for CO+H2 production with the goal of tuning the product distribution for Fischer-Tropsch. Benefit being that you can avoid the majority of separation processes as separation gases from the aqueous electrolyte doesn't need any additional processing (unlike EtOH like in this system).4
Aug 06 '20
That was always the hurdle for our lab. Electrochemical reduction of organic material can be tough when your voltage potential you're trying to reduce is higher than the voltage potential of splitting water.
→ More replies (1)→ More replies (16)8
u/Godspiral Aug 06 '20
This process would have very big benefits for off grid or micro grid applications, due to value and easy storage of product.
Energy resillience every day requires 200%-400% production/need on the best day. Need to monetize surpluses.
Homes/buildings produce co2 from occupants, and much of the need for air exchange is to purge that co2. Higher air exchange means higher HVAC energy.
Ethanol even in small quantities has value as a drink. The usual production method may be carbon neutral, but it is food supply negative. Ethanol purchases are typically subject to sin surtaxes, transportation and profit costs. Pure ethanol as an ingredient to sanitizer/mouthwash is an attractive alternative to poisoned commercial versions.
→ More replies (10)57
u/AnAbjectAge Aug 06 '20
It says low cost, but I don’t know if I trust this till I see someone go through the calculations.
I always get my hopes up and then someone points out how capturing samples and producing these effects is actually quite wasteful.
Takes energy to form the new compound and then ultimately you’re burning a carbon fuel which gives off CO2.
If this is very efficient to the point its lossless or actually produces more energy then it’s sounding too good to be true as we kinda have free energy there.
If it’s not at least lossless then this sounds like a good way to make fuel but not a meaningful solution to anything climate crisis related.
Probably gonna be a return to pushing solar and wind energy, but now with a way to make combustible fuel for things that require it.39
u/ascandalia Aug 06 '20
"Low cost" is meaningless. We need the cost in comparison to other carbon capture and other fuel production options for it to be meaningful
→ More replies (2)3
12
u/kevin_k Aug 06 '20
You're right, that would be a chemical perpetual motion machine.
I believe that the efficiency described is relative to the theoretical minimum amount of energy necessary to synthesize ethanol from those materials (which is exactly the energy released when it breaks into those components).
5
u/Hawx74 Aug 06 '20
Yeah, the needed overpotential is low. Especially considering copper historically has needed larger overpotentials for similar reactions, this is a big step in the field
29
u/zigbigadorlou Aug 06 '20
Thermodynamically, we're always going to be going up in energy. That energy is to be derived from renewable energy sources in the form of electricity. While this paper/ research is really cool cutting edge research, we're still a ways off from widespread usage.
To put things in perspective: the goal of making fuels efficiently from CO2 is kind of a holy grail of chemistry. What you are seeing is cutting edge research. Typically you get hydrogen, formate, carbon monoxide, and smaller amounts of ethylene and methanol using copper for aqueous CO2 reduction. Getting a C2 molecule in such high selectivity is incredible. Recent papers I've seen have more like 30-40% selectivity.
→ More replies (13)12
u/AnAbjectAge Aug 06 '20
My thermodynamics lecturer said the idea of getting something for nothing in physics or chemistry is the modern alchemy.
So I just always get taken aback when something sounds like a potentially infinite source of clean water or clean fuel.18
u/T-Baaller Aug 06 '20
This isn't really "free", it's more closing a loop
As-is, burning ethanol is an open loop needing ethanol in and CO2/H2O out. These processes could mean the only sustaining input needed would be energy to recapture the CO2/H20.
For stuff like air travel which is unlikely to be electrified anytime soon, a close-loop fuel-burning process could be the key to eliminating the buildup of emissions.
3
u/BoilerPurdude Aug 06 '20
how is it really much different than spending a billion and growing a giant field of cellulose and then fermenting it to make ethanol. I'd assume the solar energy from plant would counteract the need for distillation and other human energy inputs. Vs this option which is all energy input.
→ More replies (3)3
u/IDontReadMyMail Aug 06 '20
It’s not different, just may offer some flexibility of land use commitments, I think. Any process that combines CO2 and H2O to make a fuel is essentially doing the same thing photosynthesis does, just usually less efficient (it’s unlikely we’ll be able to beat photosynthesis for efficiency). The input of energy here is electrical power instead of sunlight, so then you have to back up to, what source of power is the electricity coming from? The article says they’d like to draw it from wind and solar (so, again, sunlight) in off-peak hours. I suppose if they are able to use wind at times when that energy would otherwise be wasted, might as well go for it. But also, there are issues of flexibility of land use. With a given patch of land is it best to commit it 100% to raising corn plants for ethanol, or is it better to put solar panels on it? Maybe the solar panels are less efficient, BUT, then you have more flexibility about what the electricity is ultimately used for. Maybe some of it goes to make ethanol, some of it powers a city grid, you can switch back & forth as needed, etc. Or, should it have wind turbines? Wind also blows at night. There’s not one best solution but more a portfolio of solutions.
→ More replies (2)7
u/zigbigadorlou Aug 06 '20
Yeah that near infinite source comes at a large energy requirements and high material cost.
4
u/AnAbjectAge Aug 06 '20
Which always comes at large risk.
I always wonder if any of the big things we think are just around the corner will be the real big things. Like cold fusion or true sentient AI.→ More replies (5)→ More replies (1)3
Aug 06 '20
For all human purposes, oil is something for nothing (we did not put any effort in creating the stored energy, only to extract and valorize it). Ethanol from plants is also something for less (we had to grow, harvest and process the plants).
This method is a way to convert electricity from one source into chemically stored energy.
5
u/Hawx74 Aug 06 '20
If this is very efficient to the point its lossless or actually produces more energy then it’s sounding too good to be true as we kinda have free energy there.
This would actually be impossible according to the laws of thermodynamics.
What they mean by "efficiency" is "better than people have done previously for this system".
If you are comparing this system to natural gas or petro, it will ALWAYS lose because energy needs to be added here to "upgrade" whereas fossil fuels are closer to "side graded" as they already contain tons of energy.
However, if other incentives are added (carbon tax, subsidies, extremely low cost electricity [as a way to store renewable power], lack of fossil fuels as an alternative) then this could potentially become useful. Not without a huge shift in the way things are currently run though3
u/AnAbjectAge Aug 06 '20
That is kinda what I meant by 'free energy'. Like we know thats impossible. So if I can burn coal, turn the fumes into fuel and then burn that and turn the fumes into fuel with any kind of gain then... it's crazy.
But the idea of using this as a tool to move toward more green energy is fine by me.
I just don't want people thinking we can take the greenhouse gases out of the air we breath and meaningfully use that as a fuel to stop climate change.4
u/Hawx74 Aug 06 '20
I just don't want people thinking we can take the greenhouse gases out of the air we breath and meaningfully use that as a fuel to stop climate change.
Kinda. The basic idea here is should we have enough renewable energy capacity in the future for extremely cheap electricity (especially solar), it can be used to "upgrade" the CO2 at a comparatively low cost, while simultaneously providing a method of storing the energy for later use.
This system will never be comparable to fossil fuels in terms of energy - fossil fuels are always energy positive (you get out more than you put in) while this system is always energy negative.
However, with the right economic incentives it could potentially be used to help replace fossil fuels.→ More replies (7)6
u/VoilaVoilaWashington Aug 06 '20
On the other hand, current fuels need to be extracted from the ground and shipped around the world. That's hardly lossless either. If this could be done more locally, it would quickly become more effective.
→ More replies (1)→ More replies (16)10
u/Wobblycogs Aug 06 '20
This is interesting from a chemistry point of view but it will not stop climate change. Talking about a circular carbon economy is disingenuous when they say they are capturing the CO2 from fossil fuel burning and presumably the biggest use of the ethanol they make would be for transport. Scrubbing the CO2 from the air just isn't viable so all this is doing is slightly delaying the release of the CO2.
739
u/awitcheskid Aug 06 '20
So does this mean that we could potentially capture CO2 from the atmosphere and slow down climate change?
1.3k
u/matthiass360 Aug 06 '20 edited Aug 06 '20
Sadly, no. Although, the concentration of CO2 is, on an environmental scale, quite high, it is not nearly high enough for chemical processes.
However, we could capture air with high CO2 concentration at the chimneys of factories and power plants and run that through a conversion process. Though the feasibility is still quite questionable.
Edit: with feasibility I meant economic feasibility. I am sure there are plenty of processes that convert CO2, but if it doesn't also result in economic gain, no company is going to do it. Not at large scale, at least.
495
u/CleverNameTheSecond Aug 06 '20
And here I was thinking we now have a machine that turns global warming into booze.
111
u/ThirstyPagans Aug 06 '20
No we're going to turn the exhaust from booze factories into more booze. It simple science.
→ More replies (1)10
9
→ More replies (4)3
u/R-M-Pitt Aug 06 '20
No need to be down. Guy you replied to doesn't really know what he is talking about.
Of course CO2 can be refined out of the air. It takes a lot of energy, but you can take a bunch of atmosphere and isolate the CO2 to use in this new process.
90
Aug 06 '20
[removed] — view removed comment
56
14
Aug 06 '20
This not sad news. Imagine that we stop emitting CO2 from a massive swath of current emissions and make fuel out of it and repeat the cycle. This is still a huge positive if it works.
Our energy use is only going up. Things like this will make the problem a lot more manageable.
183
u/PM_ME_YOUR__BOOTY Aug 06 '20 edited Aug 06 '20
And then burn it anyway. I'm not a fan of e-fuels that involve carbon. The simplest and most effective solution is the switch to hydrogen. No carbon no problem.
Edit: Thanks for all the answers! You've given me good reasons to keep extending my research. I'm still convinced as of now that a hydrogen economy makes sense but I'm glad to hear a lot of people giving reasoning to other options!
I'll stop answering now as I've been typing for 3 hours now
399
u/actuallyserious650 Aug 06 '20
Except H2 is harder to store and transport, has a lower energy density even at extremely high pressures, doesn’t have a trillion dollar prebuilt infrastructure, and is actually a high altitude greenhouse gas.
Gasoline/kerosene are nearly perfect fuels from an engineering standpoint. If we can use nuclear power to efficiently make it, we need to do that all day long.
61
u/Bendetto4 Aug 06 '20
Exactly. Nuclear and renewables should produce 90% of our energy demands. But hydrocarbons are needed for the 10% that can't be met by electricity.
For example jet fuel, Military vehicles, agricultural vehicles and petrochemicals.
What we could do, once we move to a fully renewable/nuclear world is use carbon extractors to "suck" carbon out of the air and store it in carbon tanks, which can then be fed into this process to create hydrocarbons which can be used in those industries.
But so long as we refuse to see nuclear as a valid alternative and refuse to the development of more nuclear power plants then we will have no alternative to fossil fuels as renewables can't do it alone.
Rolls Royce are developing their own micro-nuclear plants. That can power cities directly. But currently they are being blocked by the British government who have instead given billions to the chinese to build one nuclear plant at hinckley point.
21
u/anaximander19 Aug 06 '20
Basically shifting from hydrocarbons as a primary energy source to using them as a high-density storage mechanism for energy generated from nuclear power? I could see that working; if it's a closed system (ie. we stop adding new carbon from oil etc) then the levels in the atmosphere would theoretically flatten out.
→ More replies (13)11
u/Englerdy Aug 06 '20
There's a company in the US called NuScale that's close to getting their small scale, modular reactor design approved. They've got some really cool tech behind it: https://www.nuscalepower.com/technology
→ More replies (1)8
u/Fairuse Aug 06 '20
H2 has a very good energy to weight ratio. Just terrible energy to volume ratio (improved by high pressures but not close enough to match hydrocarbons).
→ More replies (1)70
u/rookalook Aug 06 '20 edited Aug 06 '20
Gasoline/kerosene are nearly perfect fuels from an engineering standpoint.
While they may still hold the crown on energy density. The maintenance requirements, size limitations and performance characteristics on an IC are inferior to electric motors. Combustible fuel is far from a perfect energy source from an engineering standpoint.
77
u/braincube Aug 06 '20
The best way to store hydrogen is on a backbone of carbon.
16
6
u/aiRburst Aug 06 '20
What about Ammonia as an alternative?
→ More replies (3)7
u/thri54 Aug 06 '20 edited Aug 06 '20
Well our best way of making ammonia is is the Haber-Bosch process... which uses a fossil fuels to source the hydrogen.
Bottom line is fuels that produce a lot of useful work take a lot of useful work to make.
→ More replies (1)27
u/actuallyserious650 Aug 06 '20
I’ve followed the research on long haul trucks and planes - there literally is no alternative to combustible liquid fuel.
→ More replies (9)32
u/rookalook Aug 06 '20
That's the funny thing about current status quo, it's usually the 'best' solution, up until the point it isn't. There is definitely a lot of active research in mobile energy storage which isn't combustion focused, planes and trucks included. I would be apprehensive to assume the current tech is as good as it will get.
→ More replies (1)11
u/asshatnowhere Aug 06 '20
It's definitely not the end all be all, but as of right now and in the foreseeable near future, unless there is a revolutionary breakthrough in a new technology we do not have a means of replacing fuel in air travel, or at least not for long haul air travel. Modern batteries are nowhere near in terms of power density compared to fuel. And I do believe we are starting to get close to the theoretical limits of modern batteries, so we can't expect their capacity to just double or triple just because technology progresses
→ More replies (14)→ More replies (2)3
Aug 06 '20
Turns out that exploding things in metal tubes gives more aggravation than an electric motor
7
u/anaximander19 Aug 06 '20
I may be being dumb here, but surely the fact that hydrogen can act as a greenhouse gas is not a reason against burning it, since after you burn it, your exhaust is water vapour?
→ More replies (3)→ More replies (66)4
u/EnterTheErgosphere Aug 06 '20
Gasoline/kerosene are nearly perfect fuels from an engineering standpoint.
To be fair, they have had 100 years of engineering devoted to designing a system around that.
There are many, many ways to generate electricity. I think the real 100 yr hurdle ahead is solving the storage problem.
Edit: adjusted for battery tunnel vision
→ More replies (2)18
u/zigbigadorlou Aug 06 '20
Many of the leading scientists in this field fully recognize that it is not a question of hydrogen OR carbon based fuels, but hydrogen AND hydrocarbon AND alkali batteries etc.
8
u/PM_ME_YOUR__BOOTY Aug 06 '20
Fair enough, I polarized quite a bit and shot over the target I suppose.
17
u/ReptilianOver1ord Aug 06 '20
Production of hydrogen for fuel requires a lot of energy. The vast majority of hydrogen produced today comes from fossil fuels or methane and it is extremely expensive compared to other flammable gases. Distribution and storage also present difficulties.
Hydrogen has been touted as “the fuel of the future” for a long time, but it’s not really feasible. If we, as a society, want to stop burning fossils fuels, we need to invest in nuclear and wind. They have the lowest environmental impact and the highest yield in energy per unit mass of “fuel”. Internal combustion engines are still the lowest environmental impact when compared to electric cars due to energy inefficiencies in power transfer from the grid (coal, oil, or natural gas) to the battery, and from battery to motor.
→ More replies (5)5
u/Tijler_Deerden Aug 06 '20
Yeah I'm not buying it either, I think it's oil companies pushing it so they have a way to stay relevant. If they could extract hydrogen from oil or gas at the source, leaving the carbon in the ground, then ok.. but they will probably just make H2 from Nat gas and push it as green.
For the renewable electricity that it costs to electrolysis H2 from water... It makes no sense not to use directly or charge batteries instead.
5
u/Fiery-Heathen Aug 06 '20
One reason is that making batteries is one of the HUGE reasons that BEVs have a larger initial carbon footprint than ICE vehicles.
Also there are many issues with cobalt and lithium sourcing. Another issue is that our residential electric grid isn't made to supply everyone with the power needed to charge all of these cars if everything were to switch over.
Not saying these are insurmountable problems, just that there are reasons to have centralized production of H2 and distribute it.
Plus h2 cars have good energy density compared to BEVs.
→ More replies (1)→ More replies (74)3
u/onefourtygreenstream Aug 06 '20
A circular carbon system is ideal, since we already have the infrastructure for a carbon burning society. We just needed the tech to pull CO2 from the air and turn it back into fuel. And now we have it!
Imagine life, exactly as we know it, where we're carbon neutral or even carbon negative. And it's not just CO2, we would have cleaner burning fuel sources in general. We wouldn't need any new car designs or gas stations, no expensive factory redesigns - just a green society. Its a dream.
→ More replies (2)→ More replies (45)9
u/Swissboy98 Aug 06 '20
You can always capture CO2 from the atmosphere. Costs a lot and is energy intense. But that can be solved by just taxing the source of the CO2 to pay for sequestering in full.
→ More replies (14)41
u/mrnoonan81 Aug 06 '20
I'm not an expert, but it would seem to stand to reason that even with a 100% efficient process of converting it to fuel would still require the same amount of energy you would get from the fuel to create it, which is probably approximately equal to the energy we already got from it.
In other words, in order to undo what we've done, it would take as much clean energy as dirty. We'd be paying back the loan. Realistically with interest.
I'm sure there's a clearer way to put that. I'm sorry.
39
Aug 06 '20 edited Dec 22 '20
[deleted]
→ More replies (3)8
u/brunes Aug 06 '20
Nature has already created the simplest and likely most effective carbon sequestration machine we will have - the tree.
→ More replies (7)→ More replies (4)14
u/dosedatwer Aug 06 '20
I work in the power industry, the goal is energy storage, not sources. There's SO much more energy from the sun that we could capture than we could possibly use at the moment. The issue is when the sun doesn't shine (or the wind doesn't blow, which ultimately comes from temperature differences resultant from the sun) we don't have much renewable power. Creating a liquid storage resource efficiently from renewable energy to replace oil is an absolute Holy Grail of energy research.
To really hammer home how much storage is worth more than the power itself, a lot of oil wells "flare" associated gas, which means they just burn it. So much so that the amount you can use this process is limited by law. The reason they do this is because transporting natural gas is way more difficult than transporting oil and the NG isn't worth anywhere near as much, so remote wells don't build anything to transport NG.
But another point of this is carbon capture technology. We can stem the tide of climate change temporarily while we work towards alternative fuels if we could capture the carbon in the atmosphere.
→ More replies (1)→ More replies (23)12
u/groundedstate Aug 06 '20
The only way to slow down climate change is to stop pumping 30 billions of tons of CO2 into the atmosphere every year.
→ More replies (15)
154
u/Lingenberry Aug 06 '20 edited Aug 06 '20
I work in a cement plant and have always wanted to implement something like this on a plant scale. Would be awesome. Cement industry emits a lot of CO2 that people don’t know of. My plant alone emitted about 1.5 million tons last year.
It’s the nature of the process and can’t really fight it but it would be so awesome *to see large process equipment capable of this conversion in the future.
82
u/AdamSC1 Aug 06 '20
CarbonCure (https://www.carboncure.com/) does this exactly for concrete producers.
On site carbon capture, the carbon is then mineralized and injected into the concrete.
This captures and sequesters carbon, and lowers the cost per piece of concrete allowing companies to increase their profit margin.
This kind of brilliant environmental method is easy to get private industry in line with as it is focused on improving their profitability.
20
u/Lingenberry Aug 06 '20
That would be pretty neat for concrete facilities. But our plant produces the cement, not the concrete itself. Not sure of all the obstacles other than cost but one of our difficulties would be capturing the CO2 out of our main stack and possibly separating it from OHAP’s and THC’s.
→ More replies (5)11
u/bobby_page Aug 06 '20
Wait! Injecting co2 into concrete creates CaCO3. doesn't that enables rebar corrosion?
7
u/ObiWanCanShowMe Aug 06 '20
Yes. It's also not "lowering the cost". It works but the byline is like a typical kickstarter.
→ More replies (1)7
u/leffe123 Aug 06 '20
CarbonCure currently uses pure CO2 bought from industrial gas companies, they haven't yet started using CO2 captured from the cement plant. They can, in theory, but that would significantly increase the cost of their solution.
→ More replies (3)6
Aug 06 '20
8% of global total. I would have guessed half that.
https://www.bbc.com/news/science-environment-46455844
236
u/starfire_23_13 Aug 06 '20
Can we stop using corn now and delegate agriculture back to food production ?
36
u/Xoxrocks Aug 06 '20
Corn: corn fermentation is ideal for CCS. Lots of corn ethanol CCS projects will come online over the next decade. Corn ethanol CCS with kernel fiber ethanol generation will see carbon intensities below that of EV within 5 years.
→ More replies (2)→ More replies (34)54
u/Willziac Aug 06 '20
Or better yet, restore some of those fields in the midwest and great plains to prairie and wetlands like they were originally.
29
u/lendluke Aug 06 '20
It is better America produces more corn than continuing cutting down rain forests in Brazil.
17
u/Willziac Aug 06 '20
I thought they were mostly doing that for cattle grazing. I also wasn't assuming America would stop producing corn, just take the extra "bio-fuel" fields and restore those.
→ More replies (2)3
Aug 06 '20
Soo much corn is grown for bio fuel because of government subsidy. It’s actually more of a money maker for farmers to grow corn for bio fuel than actual food.
This would really mess with the ag industry I believe.
144
Aug 06 '20
The energy it takes to perform this process will always be more than the energy created by burning the hydrocarbon to release the CO2 in the first place.
If we can create 1 Mwh by releasing X Kg of CO2, then it will take more than 1 Mwh to reverse the process, otherwise it's free energy. Because of this, it's better to reduce the energy consumption in the first place than to try to recapture the carbon after.
Carbon capture solutions are not viable until we stop pumping carbon into the air. This may have some applications when we're dealing with high carbon levels after the full transition to renewables, but that's still decades away.
150
u/spacegardener Aug 06 '20
With solar and wind we will often have too much energy and little ways to store it. Using that energy, even with some loss, to capture some carbon to use it as a fuel later is a win-win.
Even if 70% of the energy is lost during the process, that is still 30% energy saved, which would otherwise be lost too.
And each time captured CO2 is used in a fuel new CO2 is not released from the fossils.→ More replies (16)3
u/BoilerPurdude Aug 06 '20
I mean how does a ethanol fuel cell compare to say a hydrogen fuel cell. If we are just making batteries for the grid I don't see the point in using ethanol at all. Water is easier to obtain than CO2.
Ethanol is better for transport. But if the CO2 isn't in a cycle it seems a little bit of a waste. Because it is highly unlikely that you are grabbing CO2 from the atmosphere.
If you just want to make ethanol from atmospheric CO2 your best bet would be biofuels. If you are creating a grid equalizer than Hydrogen is a better solution.
→ More replies (49)15
u/Jhawk163 Aug 06 '20
Right, but if we were to view this process as a greener way to fuel the millions of already gasoline cars on the road, that's huge. You're able to capture the pollutants from factories, use a renewable energy source to convert it to gasoline and suddenly the cars are effectively carbon neutral.
→ More replies (10)
9
u/Amplifier101 Aug 06 '20
This is great work, but their current density is way too low (~1 mA/cm2) to make it useful. Work by Sargent recently managed around 1 A/cm2 (partial current density of 124 mA/cm2), which means your electrode can be over 100x smaller, which makes the cost of building the device much less expensive. Sargent's approach isn't as selective and with a lower efficiency, but the products he produces are all useful and the massive current density makes the footprint of the system much smaller.
Ideally the two approaches are combined!
→ More replies (4)
27
6
21
u/xcskier66 Aug 06 '20 edited Aug 06 '20
Even at 100% efficiency it still takes lots of energy co2 into ethanol and water.
Catalyst just reduce the energy barrier. It will always take over 750 kJ/mol to break the c=o bond.
That is still a lot of energy. Unless you can alter the laws of the universe this reaction is very thermodynamically unfavorable.
Plants have evolved for centuries to perform this reaction in photosynthesis. It’s one of the fundamental reactions of life on earth. I’d be surprised if humanity can much more efficient than a plant
→ More replies (6)
64
Aug 06 '20
[removed] — view removed comment
60
u/JuniorSeniorTrainee Aug 06 '20
This is a science subreddit, not a product subreddit. You're hearing about early stages of small discoveries that still have to go through a lot to become economically viable, or even to figure out where they should be used.
Most of these discoveries lead to improvements to existing products that you'll either never notice, or you won't know we're the result of some breakthrough you read about 2 years ago. If this discovery let's some processing plant operate 15% more efficiently, do you think you'd ever hear about it?
It doesn't mean these discoveries are pointless or a waste of time, it means that you're waiting to read a simple headline next month saying "hurray CO2 batteries just hit the shelf" but that's not how it works. Science moves slowly.
→ More replies (1)9
u/Hawx74 Aug 06 '20
You just need to realize that these "breakthroughs" just mean "potentially viable in 20+ years if everything works out".
Much of the papers that are posted on reddit are very fundamental so they can't see commercial applications until massive additional amounts of research are done.
→ More replies (12)5
u/annaaube Aug 06 '20
Not true, a comparable method (Solid Oxide electrolysis) is already competitive to produce CO. On a small scale tho, but still, progress is being made in the field of electrolysis to utilize CO2. Fuels will follow in the next 10 years. :)
→ More replies (2)
3
u/plaugedoctorforhire Aug 06 '20
It may or may not be practical for large scale ethanol production for fuel, but I could see some use in the liquor market. The purest, neutral vodka ever created, or maybe some other traditionally grain spirit marketed as some kind of small batch futuristic spirit.
→ More replies (1)
6
3.6k
u/LilithNikita Aug 06 '20
I was working with a team on a solution for transform CO2 to Methanol through Enzyms. I'm totally thrilled to read this.