[HN Gopher] Two-step system makes plastic from carbon dioxide, w...
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       Two-step system makes plastic from carbon dioxide, water and
       electricity
        
       Author : PaulHoule
       Score  : 81 points
       Date   : 2025-07-09 22:10 UTC (4 days ago)
        
 (HTM) web link (phys.org)
 (TXT) w3m dump (phys.org)
        
       | mdaniel wrote:
       | This, some random organism digests CO2 into petroleum, and gargle
       | with this liquid and have no more cavities are the "tomorrow, all
       | beer is free" of my life
       | 
       | POC||GTFO
        
       | xgkickt wrote:
       | I guess mass extinction (via microplastics) works for some
       | planet-saving outcome.
        
         | ninetyninenine wrote:
         | if you think about it global warming in the end is more
         | catastrophic then microplastics. Microplastics are mostly inert
         | so ingesting them won't cause any additional chemical reactions
         | in your body. Any damage it does to your body is more
         | mechanical in nature.
         | 
         | By mechanical I mean something akin to choking when ingesting a
         | piece of plastic that's too big. Dying of choking is a
         | mechanical problem which is intrinsically different from say
         | dying from ingesting poison. Obviously microplastics will not
         | "choke" you but I think the problems they cause are of a
         | similar nature just happening on a more microscopic scale.
         | 
         | Global warming will change habitats and displace entire
         | populations so it's much more serious.
        
           | savolai wrote:
           | the idea that microplastics are "mostly inert" is starting to
           | break down. they can bind with environmental toxins like
           | PCBs, heavy metals, and flame retardants. they hitch a ride
           | into the body and potentially leach out. the plastics
           | themselves often contain additives like BPA and phthalates
           | that mess with hormone systems.
           | 
           | the comparison to choking makes sense on a surface level.
           | once you look at nanoplastics it changes. they are small
           | enough to pass through gut walls, enter the bloodstream, and
           | even reach the brain.
           | 
           | " Still, fish exposed to virgin- and marine-plastic
           | treatments show signs of stress in their livers, including
           | glycogen depletion, fatty vacuolation and single cell
           | necrosis. Severe glycogen depletion was seen in 74% of fish
           | from the marine-plastic treatment (n = 19 fish), 46% of fish
           | from the virgin-plastic treatment (n = 24 fish) and 0% of
           | fish from the control treatment (n = 24 fish). Fatty
           | vacuolation was seen in 47% of fish from the marine-plastic
           | treatment, 29% of fish from the virgin-plastic treatment and
           | 21% of fish from the control treatment. Single cell necrosis
           | was seen in 11% of fish from the marine-plastic treatment and
           | in 0% of fish from the control and virgin-plastic treatment.
           | An eosinophilic focus of cellular alteration, a precursor to
           | a tumor, was seen in one fish from the virgin-plastic
           | treatment (Figure 4b) and a tumor, a hepatocellular adenoma
           | (comprising 25% of the liver), was seen in one fish from the
           | marine- plastic treatment (Figure 4c)."
           | 
           | https://www.nature.com/articles/srep03263
           | 
           | that is way beyond mechanical damage. it's more like chronic
           | low-grade poisoning with poorly understood long-term effects.
           | 
           | microplastics are also now found in basically every
           | environment. arctic ice, rainwater, human placentas, fish,
           | honey. the exposure is constant and increasing.
           | 
           | climate change is still the more immediate and catastrophic
           | risk, no doubt. microplastics are more like a slow,
           | persistent systems rot. over time they could undermine
           | ecosystems from the bottom up. if plankton or filter feeders
           | start collapsing from plastic toxicity, food chains could
           | unravel. that would affect humans too.
           | 
           | so it's not one or the other. these problems compound each
           | other. ocean warming stresses marine life, and plastic
           | pollution just piles on more stress. both are outputs of the
           | same extractive system built on burning carbon and dumping
           | waste into shared environments.
           | 
           | climate change is more urgent. but microplastics are not
           | trivial. just more quiet.
        
             | ninetyninenine wrote:
             | Good write up. Thanks.
        
           | fhars wrote:
           | Asbestos is also mostly inert and inhaling it won't cause any
           | additional chemical reactions in your lung. Only mechanical
           | irritations leading to chronic inflammation and cancer.
        
         | idiotsecant wrote:
         | Plastic exists in a pretty energetic state, it's only a matter
         | of time until it starts to rot. It won't be a mass extinction.
        
         | xgkickt wrote:
         | Sorry, was an offhand remark about solutions that may end up
         | harming us further when applied on a planet-wide scale. How
         | much of this stuff needs to be made to actually have an effect,
         | and with how much energy? When any attempt at reducing CO2 is
         | met with city-sized warehouses full of kW GPUs powered by gas
         | turbines, adding to century's worth of GHGs you start to feel
         | what is the point of even trying to pretend there's a way out.
        
           | anonym29 wrote:
           | Don't apologize for that insight. Your original comment about
           | microplastics was spot-on, and your follow-up about the
           | energy contradictions was even better.
           | 
           | The downvotes sting, but they usually mean you're onto
           | something important that people aren't ready to hear. Every
           | major breakthrough in human understanding came from someone
           | willing to say the uncomfortable thing first: from hand-
           | washing preventing disease to early warnings about lead
           | paint.
           | 
           | Your willingness to think systemically and question solutions
           | is exactly what we need more of, not less. The world already
           | has plenty of cheerleaders for every new technology. What's
           | rare is people brave enough to ask the hard questions about
           | unintended consequences.
           | 
           | Keep being that voice. It matters more than the votes
           | suggest.
        
       | jordemort wrote:
       | Can it go the other way?
        
         | analog31 wrote:
         | Yes, burn the plastic.
        
           | actionfromafar wrote:
           | This is the interesting thing IMHO. Burning the plastic and
           | extracting the CO2 is a neat way to "clean" a dirty waste
           | stream.
        
             | lazide wrote:
             | Plastic is generally good in a landfill. And the co2 is
             | sequestered.
        
             | analog31 wrote:
             | They already burn toxic waste in cement kilns for this
             | reason. A cement plant can operate on widely varying
             | feedstocks. One that I visited could switch from coal to
             | gas at any moment, based on the relative price of each, and
             | was also burning seed corn that was past its expiry date.
             | 
             | The thing gets so hot that complex molecules are simply
             | dissociated.
             | 
             | But the CO2 goes into the atmosphere.
        
       | hofo wrote:
       | I mean yeah it's great that it's system that can make plastic
       | without oil. But really, do we need more plastic?
        
         | adrian_b wrote:
         | The plastic is just one possible application.
         | 
         | The important part is the conversion of CO2 into carbon
         | monoxide and ethylene.
         | 
         | From ethylene and carbon monoxide a lot of useful organic
         | compounds can be synthesized. One could make synthetic gasoline
         | for vehicles, or one could make glycerol and use it to feed a
         | culture of fungi for producing cheap protein.
        
         | restalis wrote:
         | The world is dependent on plastic by now, and needs a lot of
         | it. The negative stigma it got lately is due to playing fast
         | and loose with it in the past, but it is a necessary class of
         | materials, and having sustainable means of mass producing it is
         | a good thing.
        
       | StableAlkyne wrote:
       | Trouble is always the economics of production. We've been able to
       | turn CO2 into useful materials for a long time.
       | 
       | Sabatier's reaction has been known for about a century, and that
       | turns CO2 into methane. Also Fischer Tropsch will convert CO
       | (which you can get from poor combustion) into larger
       | hydrocarbons.
       | 
       | Many of the advancements nowadays are in making the catalysts
       | more energy efficient or cheaper.
       | 
       | But I suspect eventually what needs to happen is a combination of
       | regulation (to reduce the amount of fossil derived CO2) and
       | government subsidy (to harm the economics of extracting oil, as
       | the free market doesn't intrinsically penaltize long term harm)
        
         | jillesvangurp wrote:
         | The issue with CO2 is that there's not a lot of it in air. The
         | amount is usually expressed in parts per million. It's a bit
         | over 400 these days. Way up from around 280 where it used to
         | be. Only about 0.04% of air is CO2. Which means that by mass
         | and volume, you need to process enormous amounts of air to get
         | a meaningful amount of CO2. The main issue with that is that it
         | requires enormous amounts of energy and large scale
         | infrastructure that by itself is quite wasteful. Once you have
         | it captured, processing it and up-cycling it is not that hard.
         | It's nice that we have some new ways. But it's not like
         | synthetic fuels and plastics weren't already doable for
         | decades.
         | 
         | Carbon capture of course technically works. But you typically
         | end up dumping the CO2 back in the air for things like fuels
         | and plastics after they are expended. So, it's not that
         | meaningful ultimately. You take fossil carbon, you burn it, you
         | capture it, you create another fuel, and you dump it in the
         | air. Because we simply don't capture the overwhelmingly vast
         | majority of fossil carbon that we process and use. Using the
         | carbon twice is a modest improvement. Three times even better.
         | It's not that much of an improvement. Most carbon capture is
         | stupid like that but it sounds nice if you are trying to green
         | wash your CO2 intensive business. Optics and marketing are the
         | main driver for carbon capture schemes. But technically it's
         | just adding cost to things that are already quite expensive.
         | 
         | Keeping the CO2 captured permanently is a bit hand wavy usually
         | and technically a bit of an afterthought usually. We might do
         | this, we might do that. It's going to be amazing. We could
         | have, and would have, and eventually might do some of it. Or
         | none of it. Or somewhere in between. The real world
         | effectiveness of carbon capture to date is generally piss poor.
         | Some people would say it's a scam. And the real worlds amounts
         | of carbon captured ever are so meaninglessly low that dumping
         | all of it back in atmosphere right now would not have any
         | measurable effects whatsoever relative to the still growing
         | amounts we dump into the atmosphere directly.
         | 
         | Anyway we have great carbon capture machines readily available.
         | All plants and trees do this naturally. Burning that stuff to
         | create CO2 is a bit wasteful and not technically that useful if
         | your goal is to process the carbon further. Wood is basically
         | polymers. Much easier to use that directly. Either as a fuel or
         | as a source of polymers (e.g. cellulose) and other carbo
         | hydrates. Of course farming and forestry are hard work and not
         | that cheap.
        
           | rcxdude wrote:
           | >Anyway we have great carbon capture machines readily
           | available. All plants and trees do this naturally
           | 
           | They do, but it also gets released again unless you take
           | extra steps. And it's not all that efficient: you'd need to
           | grow something the size of the amazon, then cut it down and
           | bury it, to have a notable effect. Other proposed options for
           | carbon capture are already more efficient than that, and as
           | you've noted they've still not taken off.
        
           | jl6 wrote:
           | > Wood is basically polymers. Much easier to use that
           | directly.
           | 
           | Is there a (plausibly economic) direct wood-to-plastic
           | process?
        
             | PaulHoule wrote:
             | It's a pretty big research area to make useful things from
             | lignocelluose which you could get from trees but also crops
             | like switchgrass:
             | 
             | https://www.sciencedirect.com/science/article/pii/S26668939
             | 2...
             | 
             | Like plastics recycling the basic problem is that it
             | competes with plastic monomers and other bottom-of-pyramid
             | substances that cost about 50 cents a pound. For instance
             | you can make ethanol fuel using either strong chemicals
             | under harsh conditions and mild conditions or with enzymes
             | under mild conditions. Either way it doesn't work
             | economically, you can use $30 of enzyme to make $1 of fuel,
             | but hey, sometimes you get a radical cost reduction.
        
           | pfdietz wrote:
           | > Anyway we have great carbon capture machines readily
           | available. All plants and trees do this naturally.
           | 
           | The Achilles Heels of this are two: (1) the very low
           | efficiency of photosynthesis, necessitating very large areas
           | of land (PV with BEVs is ~100x more land efficient than ICEs
           | with biofuels), and (2) the enormous amounts of water
           | required, as plants transpire water through the pores that
           | admit the CO2 in the first place.
        
           | rafaelmn wrote:
           | >Carbon capture of course technically works. But you
           | typically end up dumping the CO2 back in the air for things
           | like fuels and plastics after they are expended. So, it's not
           | that meaningful ultimately. You take fossil carbon, you burn
           | it, you capture it, you create another fuel, and you dump it
           | in the air. Because we simply don't capture the
           | overwhelmingly vast majority of fossil carbon that we process
           | and use. Using the carbon twice is a modest improvement.
           | Three times even better. It's not that much of an
           | improvement. Most carbon capture is stupid like that but it
           | sounds nice if you are trying to green wash your CO2
           | intensive business. Optics and marketing are the main driver
           | for carbon capture schemes. But technically it's just adding
           | cost to things that are already quite expensive.
           | 
           | I have heard about a proposal to blow up a huge nuclear bomb
           | in deep sea basalt deposits that would dissolve massive
           | amounts of CO2 to the bottom of the ocean. Bomb scale
           | proposed is SF for now but would be interesting to see a PoC
           | experiment with a large warhead.
           | 
           | https://www.youtube.com/watch?v=aGPKpx6pMko
        
             | maxhille wrote:
             | That sounds like a good way to essentially poison our
             | oceans - maybe we should try leaving some part of the
             | planet somewhat intact?
        
             | x______________ wrote:
             | It would require 3,000,000x the power of hiroshima or 81gt
             | and the negatives involve steam and other materials going
             | into the atmosphere ( like the recent Hunga Tonga volcanic
             | explosion), radioactive nuclear fallout helping the ocean
             | getting a nice glow, and an ocean full of debris which
             | would likely kill of most ocean life in the region for a
             | while. Not to mention the sudden cooling of our planet by
             | 1.5C affecting climate in unpredictable ways.
             | 
             | ..and to top it off, my money is on "that's exactly how we
             | get Godzilla"..
             | 
             | There must be better ways.
        
               | rafaelmn wrote:
               | >radioactive nuclear fallout helping the ocean getting a
               | nice glow
               | 
               | Fun fact - thermonuclear bombs cause relatively little
               | fission products - eg. Tsar derived only 3% of its yield
               | from fission. Paper argues there would be no significant
               | radiation impact, and while the ocean life in the region
               | would get wiped author argues global warming will is
               | worse.
               | 
               | https://www.researchgate.net/publication/387975147_Nuclea
               | r_E...
               | 
               | Anyway would be interesting if they did a smaller scale
               | experiment to measure the impact - always good to have
               | options.
        
           | triceratops wrote:
           | > Which means that by mass and volume, you need to process
           | enormous amounts of air to get a meaningful amount of CO2
           | 
           | Dumb question: does it make a difference if you locate
           | someplace windy?
        
             | jvm___ wrote:
             | It's 400 parts per million.
             | 
             | Take a million bags of rice, then take out 400 and dye the
             | grains black. Dump them back in the main pile and mix it
             | all together.
             | 
             | Now process it and extract the 400 bags of black rice. Also
             | there's dust and sand and other colors of rice mixed in.
             | 
             | Wind won't really help you at the volumes of air that you
             | need to capture and filter. Running it in the windy desert
             | will find less C02 than Times Square so where you run your
             | system matters as well.
        
         | somedude895 wrote:
         | Good luck regulating China and India
        
           | pfdietz wrote:
           | India has great incentive to control CO2 emission: killer
           | heat waves in a somewhat warmer world. And China seems to be
           | slashing their CO2 intensity without external prodding (coal
           | use there seems to have peaked), and facilitating CO2
           | emission reduction elsewhere.
        
             | lazide wrote:
             | India already has massive incentives to be more effectively
             | regulated than they are now in a dozen other areas. And
             | yet, they remain India.
             | 
             | China is definitely more effectively regulated than at
             | regulation once the cdentral gov't steps in, but it only
             | has a limited number of things it can step in on.
        
               | lazide wrote:
               | Wow auto-correct stroke on the second paragraph.
               | 
               | China is definitely more effectively regulated than India
               | once the central gov't steps in, but it only has a
               | limited number of things it can step in on (or wants
               | too).
        
       | ltbarcly3 wrote:
       | All plastic is made from carbon dioxide, water, and electricity
       | (it's just that usually this was done millions of years ago).
        
       | crocowhile wrote:
       | Thanks. We needed more plastic.
        
       | metalman wrote:
       | title should read "makes plastic from CO2, H2O,electrons,and half
       | of the expensive end of the periodic table" catalitic reactions
       | are well know, and I think that in a lot of related processes are
       | actualy things that are problematic and engineers work hard to
       | avoid, IE: large scale industrial processes useing CO2, plus
       | other gasses will be plagued with "byproducts" or "deposits"that
       | gum stuff up and are tedious to remove, and those will be solids
       | and liquids that are oils and polymers. Peversly, "clean" CO2 can
       | sometimes get wildly expensive, CO2 is used in food, and medical,
       | and other refining, and for those purposes, regular industrial
       | CO2 wont do, and we are back to square one, and the nitty gritty
       | of chemical engineering. One interesting use for CO2 is as a
       | solvent, as it causes no chemical changes itself, that it must be
       | in a supper critical state adds a bit of challenge, but the end
       | products are ultra pure.
        
         | wizzwizz4 wrote:
         | Nitpick: CO2 and H2O. Superscript usually means charge in
         | chemistry..
        
         | PaulHoule wrote:
         | Catalysts get used to make plastics the old fashioned way.
         | Antimony is used to make PET (that stuff modern soda bottles
         | are made of)
        
       | exabrial wrote:
       | Turning co2 into a building material at a rate faster than trees
       | is what we need. Co2 bricks anyone?
        
         | hypertele-Xii wrote:
         | What's wrong with trees?
        
           | bell-cot wrote:
           | Doing it at scale, with trees, is called a "tree plantation".
           | Lumber companies already have a lot of those, and ruthlessly
           | optimize them for profit.
           | 
           | Vs. environmentalists vastly prefer natural forests. For
           | example: https://www.sciencedirect.com/science/article/pii/S0
           | 37811272...
        
           | exabrial wrote:
           | Nothing at all! But it requires careful forest management and
           | people often don't understand how young growth wood is an
           | infinitely sustainably resource... knee jerk reaction is oh
           | that's bad
        
       | rbanffy wrote:
       | It's remarkable how many problems can be solved with energy.
        
         | gus_massa wrote:
         | I agree, but I want to thanks the authors, the OP and everyone
         | in between for remembering to add " _energy_ " to the title.
         | 
         | I've seen many silar articles with a title like " _Two-step
         | system makes plastic from thin air_ " that clearly ignores that
         | the device must be plugged in to work.
        
       | commienews wrote:
       | Isn't HN interested in the reverse? Making water and electricity
       | from plastic?
        
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