[HN Gopher] Launch HN: Heimdal (YC S21) - Carbon neutral cement
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Launch HN: Heimdal (YC S21) - Carbon neutral cement
Hi HN, I'm Marcus, I'm the co-founder of Heimdal together with Erik
(https://www.heimdalccu.com/). We remove atmospheric carbon dioxide
and trap it in materials that are used to make cement. More CO2 is
trapped in our process than is re-emitted in cement production.
Concrete is responsible for 8% of global CO2 emissions. Cement is
usually made from mined limestone, which is one of the largest
natural stores of carbon dioxide. Using that to make cement is a
bit like burning oil. The world is addicted to concrete, so this
problem is not going away. We make synthetic limestone using
atmospheric CO2, such that when it is used to make cement, the
process is carbon neutral. We were both master's students in
engineering at Oxford University in the UK. I decided to write my
dissertation on direct air capture of CO2. While looking through
existing solutions it struck me that none were sufficient. They all
operated a circular process that left them with gaseous CO2 that
needed to be stored somewhere. A circular process is one that uses
a sorbent to trap atmospheric CO2 but then re-releases the trapped
CO2 as a pure gas stream to regenerate the sorbent for re-use. We
don't have enough high-quality cheap stores of CO2 to justify such
an approach. Storage must be permanent and safe. We realized that
by taking a linear approach, we both make the process of capturing
CO2 profitable and avoid the problem of where to store the CO2. We
make sorbents for trapping CO2 in the form of mineral carbonates,
these compounds are inert and trap CO2 for millions of years. They
can also be commercialized as raw materials for making building
materials including glass and concrete. In one step we solve three
key problems of carbon capture: 1. How to trap CO2 energy
efficiently 2. How to store the CO2 3. How to make money while
doing all this. Specifically, we use renewable electricity to
extract dissolved oceanic CO2 as mineral carbonates of calcium and
magnesium by contacting seawater with our proprietary alkaline
sorbent. These mineral carbonates are important ingredients in
cement as well as other building materials. The undersaturated
ocean then re-absorbs an amount of atmospheric CO2 equivalent to
the amount we removed when reacting with our sorbent. Effectively,
the world's oceans become our air contactor. There are other
companies addressing emissions from concrete production, but they
don't address the unavoidable process emission from the raw
materials used in concrete. Start-ups in this space have so far
focused on curing concrete with CO2 at the end of the production
process. These are great solutions that can create low-carbon
cement, however they'll never get to carbon neutral cement that the
world needs. The 70% of emissions from production are not being
tackled by anyone on the market today. Until now concrete producers
have favoured capturing emissions at the point where they're
released as their "2050-solution", ie. in the distant future. Point
source carbon capture can expensively capture 80-90% of emissions.
This solution has the same problem as circular DAC solutions where
a method of permanent CO2 storage is needed. There is a trial $3B
(!) project in Norway to pump CO2 into empty gas fields at a cost
of ~$1000/tCO2. This is expensive and complicated engineering. On
the other hand, all we need is renewable electricity and seawater.
We make money from selling synthetic limestone to cement producers
and commercializing parallel byproducts including green hydrogen
and desalinated water. We also generate carbon credits from our
process. We are currently negotiating with concrete producers to
decarbonize their limestone supply. Response has so far been very
positive with multiple LOIs signed with producers across Europe. We
are also working with a construction company to build the world's
first carbon neutral houses this decade. We are currently building
a demo plant just outside Oxford. It has the capacity to remove and
store 1 tonne of CO2 per year. We will use this plant to make
enough product that we can deliver to our commercial partners to
confirm compatibility with their manufacturing set-up. Following
successful testing, we will scale this up to replace all of global
limestone mining; currently >2 billion tonnes of limestone per
year. We're excited to hear any thoughts, insights, questions,
encouragement and concerns in the comments below! Erik and I will
be monitoring the thread over the course of today to answer any
questions. Also feel free to reach out to me by email at
Marcus.lima@heimdalccu.com.
Author : marcuslima
Score : 571 points
Date : 2021-08-02 14:26 UTC (1 days ago)
| nostromo wrote:
| This is great to hear. Most people don't know how bad concrete is
| terms of Co2. If you tell people that it's several times worse
| than aviation in terms of carbon, few people will believe you
| until they look it up.
|
| We tend to focus on obvious sources of carbon: fuel and
| electricity, probably because it's something we all have some
| familiarity with. Agriculture and industry are hidden from our
| day-to-day lives, so few people are aware of their massive
| impacts on climate.
| marcuslima wrote:
| So true, it's a surprising statistic to most that 8% of global
| emissions is actually from concrete
| [deleted]
| [deleted]
| Angostura wrote:
| I wish you the very best of luck. The kind of company that I'd
| like to be involved with and I'mm sure the same goes for others
| here.
|
| Just one thing.
|
| https://www.heimdalccu.com/our-story linked from your front page
| gives 'Page Not found'
| marcuslima wrote:
| Thanks a lot! Stay posted for open roles - we'll be needing to
| add to our team in the next few months.
|
| Thanks for pointing out - will sort this out!
| [deleted]
| pmat wrote:
| Very cool! It sounds like your sorbent requires calcium to
| precipitate calcium carbonate from sea water. What would be the
| source of this calcium? Hopefully it won't come from reducing
| lime!
| marcuslima wrote:
| The calcium all comes from dissolved calcium bicarbonate - we
| trigger precipitation by shifting bicarbonate to carbonate
| ions, which are insoluble. Essentially we acceelrate the
| oceanic carbonate cycle
| LeifCarrotson wrote:
| I understand that calcium salts and bicarbonate ions are
| common in the ocean, and are increasingly common as the
| oceans become more acidic, but have no idea how common that
| is.
|
| How much seawater do you need to get one kg of CaCO3
| precipitate?
| marcuslima wrote:
| We're actually working on figuring this out. Our current
| calculations assume we need to process a huge amount of
| seawater (11,000 tonnes per tonne of CO2), if the CO2 is
| the limiting factor (2000 umol). However our R&D suggests
| undersaturated seawater re-absorbs CO2 from the air
| surprisingly quickly. Might be able to get this 10x lower
| ephbit wrote:
| Wow .. 11,000 tonnes of seawater per tonne of CO2 is
| indeed huge.
|
| Assuming that the new process stochiometrically generates
| CaO according to the amount of CO2 taken up from the
| ocean you'd produce 1.27 tonnes of CaO per tonne of CO2.
| (molar masses of CO2 and CaO: 44 g/Mol and 56 g/Mol)
|
| Cementa website states [1] an annual output of 2.7
| million tonnes of cement.
|
| So in order to produce what is only a portion of Sweden's
| (a comparatively small country) annual demand for cement,
| Heimdal's process would require processing of ~ 23
| billion tonnes of seawater.
|
| That's 23 billion cubic metres or 23 cubic kilometres per
| year or ~ 730 litres of seawater per second.
|
| [1]: https://www.cementa.se/en/about-cementa
| twic wrote:
| Is it surprising? Carbon dioxide equilibrates between
| salty water and air fast enough to keep every single
| terrestrial animal on the planet alive, after all.
| justshowpost wrote:
| If this is as good as promised, you should apply for Elon Musk's
| XPRIZE [1]. Take the $50 million to scale this up faster. Plus,
| if you win you probably get to talk to Elon. I doubt there is
| anyone that has better tipps on how to scale and iterate a
| business than him.
|
| [1]: https://www.xprize.org/prizes/elonmusk
| marcuslima wrote:
| Definitely one for us to get involved with. Unofrtunately it's
| a 5 year timeline, but that's still not a bad ROI
| uxp100 wrote:
| I was just talking to a friend a week ago who is pretty deeply
| interested in concrete. A Civil engineer who had been considering
| physics research before eventually ending up taking the civil
| route. A few years of "designing" bridges (they tend to be all
| about the same, for good reason) and he remains pretty fascinated
| by the materials and how much room remains (he thinks) for
| innovation in a very old material, but you know, is a little sick
| of the day to day.
|
| Any tips for what exists out there in the world of "exciting"
| concrete? Talking to him he didn't have too much idea what even
| existed for research, or if civil/physics was an appropriate
| background for working at least close to research in concrete.
| plaidfuji wrote:
| As far as I'm aware "aerated concrete" is the next step up in
| concrete tech:
|
| https://www.buildinggreen.com/news-article/autoclaved-aerate...
|
| It's lighter, less energy intensive, better insulator,
| basically just by inserting bubbles into the structure. Widely
| used in Europe but not adopted by the US because lumber is
| cheap and we don't have any established manufacturers.
| coryrc wrote:
| That and lumber is stored carbon while concrete releases CO2
| (at least for now).
| wanderingmind wrote:
| Do you have a patent or publication that describes this process.
| In particular I'm interested to know the thermodynamic efficiency
| and also the timescales involved in adsorption of CO2.
| TrispusAttucks wrote:
| Good luck!
|
| Sustainable cement and concrete production is needed now more
| than ever. Many people do not realize that the [1] cement
| industry is one of the main producers of carbon dioxide
| greenhouse gas emissions.
|
| [1]
| https://en.m.wikipedia.org/wiki/Environmental_impact_of_conc...
| marcuslima wrote:
| Thanks! Yes it's pretty wild - fully 8% of global emissions!
| SamBam wrote:
| Very cool.
|
| What would the net effect on carbon be (presumably the carbon not
| emitted + the carbon captured) per ton of concrete?
| marcuslima wrote:
| Thanks! Actually the process is carbon negative as not all is
| stored as carbonates that can be used in cement production. But
| for the materials we sell it's 1:1. One molecule of CO2 is
| captured for every molecule that's emitted in production
| comex wrote:
| What's the greatest challenge or limitation, technology- or
| business-wise, that your startup faces? If it fails, why will it
| fail?
| marcuslima wrote:
| Honestly, our biggest problem right now is moving quickly. In
| the next 6 months our biggest problem will be getting planning
| permission to stick large pipes into the sea to process large
| amounts of seawater ;) We don't discharge anything but seawater
| undersatured with CO2 so we're not negtaively impacting the
| surroundings. But government is slow with these things
| rossjudson wrote:
| I guess that all depends on which government you're talking
| to, and where.
|
| Here's my random question. Assume your process works
| perfectly, and truly represents a solution to the CO2
| problem.
|
| Some very wealthy person shows up at your door, and offers
| you and your partners serious money to put the entire idea
| and process into the public domain, and release all IP rights
| worldwide, immediately.
|
| How much?
| dmix wrote:
| > Until now concrete producers have favoured capturing emissions
| at the point where they're released as their "2050-solution"
|
| Just curious: at what point does concrete release C02? In a
| particular part of the manufacturing process? Or throughout the
| process?
| layoutIfNeeded wrote:
| https://en.m.wikipedia.org/wiki/Cement_kiln
| dmix wrote:
| Thanks that answered my question.
| twic wrote:
| > We are currently building a demo plant just outside Oxford.
|
| Where are you going to get the seawater?
| marcuslima wrote:
| We're currently driving it up in a van from Southampton!
| stevage wrote:
| What's the long term plan?
| twic wrote:
| Bigger van.
| brilee wrote:
| I'm not sure I understand where the carbon savings comes from.
|
| The cement industry specifically needs lime, CaO. Lime is most
| easily obtained by burning CO2 off of limestone, CaCO3. As you
| point out, this is effectively "burning off" captured carbon
| dioxide and is bad.
|
| Where does the carbon savings come from when the ultimate
| destination is to just burn CO2 off and make the actual desired
| product, CaO? Is this process ultimately just a better way to
| make CaO?
| marcuslima wrote:
| Yep, exactly! The world needs CaO for cement. We have a carbon
| neutral process for making it. It's actually overall negative
| as not all carbonates we extract are usable in cement
| production. But as far as cement producers are concerned it's
| carbon neutral.
| m12k wrote:
| A way to help explain this to people is that it's the
| equivalent of rapidly growing trees and burning those for
| fuel instead of burning fossil fuels.
|
| You do the same with limestone, rapidly creating it by
| capturing atmospheric CO2 (indirectly, via the ocean) so it
| can then be burned in cement production instead of the
| naturally occurring kind. In both cases, CO2 is released into
| the air at the end when the product is burned, but because
| the released CO2 had just now been sucked out of the air
| anyway (instead of having previously been sequestered in
| natural limestone) you're not adding to the total amount of
| CO2 in circulation in the system, making the process neutral.
| _nalply wrote:
| Additionally governments could buy limestone and not use
| it. Carbon sequestration. The money could come from a
| CO2-tax.
|
| I really hope this is scalable worldwide.
| hwillis wrote:
| why does removing carbonates cause the ocean to absorb more
| CO2, though? Calcium and magnesium oxide aren't just floating
| around the ocean waiting to absorb more CO2. Removing salts
| does not lower oceanic acidity.
| marcuslima wrote:
| The ocean and the atmosphere exist in an equilibrium there
| is a 'balance' of relative concentration of CO2. Because
| CO2 can dissolve in water as CO3 and HCO3 the concentration
| is skewed to a higher concentration in oceans. When we take
| out CO2 from the oceans we lower the relative
| concentration, so we shift it out of balance. So the entire
| ocean becomes the surface area for re-absorbing CO2 from
| the atmosphere to re-establish that balance!
| hwillis wrote:
| But the re-absorbed CO2 will come from new _limestone_
| dissolving into calcium bicarbonate, not from atmospheric
| CO2.
|
| You'll be adding more CO2 to the air -increasing oceanic
| acidification- while increasing the ocean's ability to
| dissolve more CaCO3. Far from fighting global warming it
| sounds like this will put exactly as much CO2 into the
| atmosphere _and_ double the leaching impact on shellfish
| and coral.
|
| I am shit at chemistry and would _really_ like cement to
| not release CO2, but I don 't understand this.
| PeterisP wrote:
| Wait, no, why? As far as I understand the process of
| limestone dissolving into oceans is the long term (on the
| scale of millions of years) process and is based on
| _rivers_ dissolving limestone so would not be affected by
| the ocean changes; in the short term (days
| /years/centuries) it would be balanced simply by CO2
| exchange between the atmosphere and what's dissolved in
| the ocean.
| marcuslima wrote:
| Yeah absolutely, the CO2 balance comes from re-
| equilibration with the atmosphere. The rivers replenish
| calcium content on a longer time scale. But as you point
| out we're in no danger of running out of calcium in the
| oceans
| flyingsilverfin wrote:
| Same question! As I understand it: CO2 pulled out of the
| ocean is replenished by atmospheric CO2, because
| limestone in the ocean dissolves too slowly to make up
| for the imbalance and it more readily comes in from the
| air. But if that's true, then the calcium will actually
| not be replenished quickly in the ocean (not sure what
| the significance of this is)! If it were true that the
| calcium is dissolved fast enough to replenish, then there
| must also be CO2 released from underwater limestone?
| Which means extracting Ca and CO2 will not remove any
| atmospheric CO2 really.
|
| Alternatively, we do end up extracting Ca from the ocean
| that is not replenished (there's probably so much we
| don't care) and rely on the atmospheric CO2 to correct ph
| balance of the ocean?
| froh wrote:
| so there is no more additional burning of limestone needed?
| instead your process directly produces the lime, CaO? and
| that then binds the CO2 when curing?
|
| to my limited understanding cement production emits CO2 in
| two ways: by splitting limestone into lime and co2 and by
| burning carbon based fuels to split the limestone.
|
| your method addresses both sources of co2 from cement
| production? or just one of them?
| tablespoon wrote:
| > so there is no more additional burning of limestone
| needed? instead your process directly produces the lime,
| CaO? and that then binds the CO2 when curing?
|
| The OP says they'll make money by selling synthetic
| limestone ("We make money from selling synthetic limestone
| to cement producers..."), so I think the CO2 still needs to
| be burned off of it before the cement is produced. However
| they say they already (indirectly) pulled that same CO2 out
| of the air, instead of the ground, so overall the process
| is carbon neutral.
| robinsoh wrote:
| > they say they already (indirectly) pulled that same CO2
| out of the air, instead of the ground, so overall the
| process is carbon neutral.
|
| I find that difficult to understand. If the output is
| CaCO3 that still needs to kilned to make CaO, then CO2
| gets emitted. Even if that volume of CO2 was obtained
| from dissolved CO2 in the ocean, one would have had to
| expend energy to extract that CO2 from the ocean and that
| energy would have generated emissions as well.
|
| If the output of this is just CaCO3 again, then I fail to
| see how this is a better solution than carbon capture
| using a clay geopolymer technique that goes directly to a
| concrete like structural material. What I mean is,
| wouldn't it be better to just skip all of this and go
| focus on rediscovering the technology for "creating" rock
| like what was possibly achieved at Cuzco (Hatun Rumiyoc)
| or Pumapunku? Or more realistically in the short term,
| using fly ash and silica flume or slag to make concrete
| without requiring CaO?
| tablespoon wrote:
| > one would have had to expend energy to extract that CO2
| from the ocean and that energy would have generated
| emissions as well.
|
| I suppose they could planning to use renewable energy?
|
| > If the output of this is just CaCO3 again, then I fail
| to see how this is a better solution than carbon capture
| using a clay geopolymer technique that goes directly to a
| concrete like structural material.
|
| I don't have a horse in this race, but one possibility is
| that concrete is a better understood material than some
| novel "concrete like structural material," so it's more
| acceptable in safety critical situations (e.g. people
| know how it fails, how to detect failures, how to
| remediate problems, etc.).
| robinsoh wrote:
| They'd also need a significant source of Calcium.
|
| > one possibility is that concrete is a better understood
| material than some novel "concrete like structural
| material," so it's more acceptable in safety critical
| situations (e.g. people know how it fails, how to detect
| failures, how to remediate problems, etc.).
|
| Your explanation and argument looks correct to me.
| However, I should point out that concrete structures fail
| regularly and frequently, and sadly with great loss of
| human life, most recently in Miami. I should also point
| out that I've seen this argument used as a tactical
| trick. I watched a Microsoft rep using this argument
| successfully convince a management team that they should
| use Embedded Windows instead of Linux because, just as
| you pointed out, "we know how it fails", "we know how to
| detect failures", "we know how to remediate problems".
| tablespoon wrote:
| I think the difference between materials and software
| through is that with materials, there's definitely a
| better understanding that comes with actual aging that
| you can't really get otherwise.
|
| With some new material, they'd probably need to rely
| significantly on accelerated aging tests (at least for a
| few decades), and there's always the question with those
| of how accurately those actually model real aging under
| real conditions.
|
| That's not to say they shouldn't try new materials, just
| that the rollout probably should be slower, and maybe not
| so good for tackling climate change. For that reason, I
| can see the benefit of a less carbon intensive way to
| produce an existing material, since that could be rolled
| out/scaled up immediately without some of the concerns of
| alternatives.
| froh wrote:
| yes that kilning is what bothers me, not for the co2 that
| is captured at sea, released in the kiln. that is then
| recaptured when curing, isn't it?
|
| what bothers me is the 1400degC needed in the kiln. to my
| understanding the ratio of limestone-to-lime co2 to fuel-
| for-the-process co2 is 2:3. you need lots of co2
| intensive energy for that kiln.
| hippari wrote:
| they said the H2 produced can be used for kilning.
| marcuslima wrote:
| Our process produces calcium carbonate, CaCO3, which cement
| producers can then burn to make quicklime, CaO. This does
| release CO2 but that CO2 has been captured from the
| atmosphere in the process of making that calcium carbonate.
| We only address process emissions (ie. splitting CO2 from
| CaCO3), but we do also produce hydrogen on-site, which can
| be used to replace fossil fuels in generating the requisite
| heat
| froh wrote:
| ok so your cement does not expose additional co2 from the
| lime-to-quicklime transformation, instead it takes co2
| from the oceans. that is released to zhe athmosphere
| during cement production. and that co2 from the air is
| then recaptured by the ocean. so your process creates a
| ocean-co2 -> air -> ocean cycle.
|
| and when and where the hydrogen is replacing some carbon
| based fuels, somehwere, that counterbalances the carbon
| based fuel used in the cement furnace.
|
| now I get how it becomes carbon neutral overall.
|
| do you guys have data points at hand how long it takes
| for an ocean to recapture the co2?
| brilee wrote:
| A followup question... how do you regenerate the alkaline
| sorbent? It gets acidified in the process of extracting CaO
| from the water and needs to be made alkaline again somehow.
| twic wrote:
| He mentions producing hydrogen as another product, so I
| would guess they use electricity to turn protons into
| hydrogen gas, so removing acidity.
| [deleted]
| robinsoh wrote:
| I'm probably missing something obvious.
|
| > The world needs CaO for cement. We have a carbon neutral
| process for making it
|
| vs
|
| > We make synthetic limestone using atmospheric CO2, such
| that when it is used to make cement, the process is carbon
| neutral.
|
| Do you make CaO or CaCO3?
| marcuslima wrote:
| We make CaCO3, I mention CaO here because that's what
| cement producers ultimately need. They heat up limestone
| (CaCO3) to make CaO
| coryrc wrote:
| Is there a reason not to make quicklime instead of
| limestone?
| xyzzy21 wrote:
| Good luck but the laws of physics, chemistry and economics are
| against you... just saying!
| ne0flex wrote:
| Very interesting. I'd definitely like to hear more about your
| business plan and your plans moving forward. I work for a
| Japanese bank and help connect startups with the bank's Japanese
| corporate clients in the US, and Asia (and soon Europe). Many of
| the bank's clients are looking for solutions like this. Happy to
| connect if you're interested.
| meling wrote:
| Very cool! Wish you best of luck!
| pierre wrote:
| I would love to see you success!
|
| Do you have more technical details on your process? Did you
| publish anything? I try to dig more on your website but the
| content is rather thin (I learn more about what you are doing by
| reading your post here).
|
| What are the by product? You mention cement and drinkable water,
| but there should be other byproduct to handle such as brime?
| marcuslima wrote:
| Thanks a lot for that! We have very little published at the
| minute for patent reasons. It's actually pretty neat as we
| consume the waste brine in the process, so nothing to disturb
| local marine life as you have issues with at reverse osmosis
| desalination plants
| toomuchtodo wrote:
| What do you find to be your greatest challenges when marketing to
| existing partners in this space? From an engineering perspective,
| it seems to be a "no brainer", but I'm curious to hear the push
| back or objections (if any) you've received.
| marcuslima wrote:
| Existing players have all been overwhelmingly positive! From
| their perspective we're not competing with their core business
| and they don't have to change any of their existing plants to
| use our product. All they have to do is buy from us rather than
| a mining company to get carbon neutral cement. The main push-
| back is the need to perform testing on the product to make sure
| they udnerstand performanc before integrating in production at
| scale. The biggest problem on our side is sorting out planning
| approval to build facilities on the coast that use seawater
| toomuchtodo wrote:
| Tremendous news, thanks for sharing. Best of luck with your
| product.
| marcuslima wrote:
| Thanks!
| tcgv wrote:
| Great project, congrats!
|
| Regarding this statement:
|
| > The undersaturated ocean then re-absorbs an amount of
| atmospheric CO2 equivalent to the amount we removed when reacting
| with our sorbent
|
| How can it be effectively measured/confirmed? Were you able to
| produce data to prove it, or is it a theoretical assumption?
| eloff wrote:
| When you need a senior/lead level software engineer, contact me
| (info in profile.) It'd be nice to work on something that could
| really, actually, literally make the world a better place.
| marcuslima wrote:
| Thanks, will keep you in mind! Watch out for posts on Work at a
| Start-up for when we expand our team in the next few months
| maxekman wrote:
| Really inspiring to see some progress in this area. Capturing in
| cement is indeed pretty clever! I wish you the best of luck to
| scale up production.
| marcuslima wrote:
| Thanks so much!
| bbyford wrote:
| wow, long and interesting thread! I'm sure people have already
| pointed out but your website needs a content overhale to actually
| say what your doing and roughly how... also, tangent question,
| can concrete be made from concrete? just thinking what happens
| when we cover the earth in the stuff we could use something else
| or reuse?
| m12k wrote:
| If your solution for generating limestone is carbon neutral, does
| that mean that if it were combined with other approaches that
| inject CO2 back into the cement while it is curing (e.g.
| CarbonCure or similar, see [1]) we could actually achieve net
| carbon capture from cement? Might make sense if that allows extra
| credits to be sold in the EU ETS, assuming the curing-injection
| process is also economically viable. I'm just thinking that some
| of your competitors in the space might turn out to be future
| partners, because your approaches complement each other.
|
| [1] https://arstechnica.com/science/2021/07/quest-for-green-
| ceme...
| marcuslima wrote:
| Yep, absolutely right! Combining our product with something
| like the carbon curing tech of Solidia or CarbonCure would make
| a net-negative concrete. I don't consider us competitors at
| all!
| matsemann wrote:
| Curious about the name, my immediate thought (and interest making
| me click in) was that it sounds Norwegian. Any connection?
|
| I really like the idea. One thing I'm curious about is what's in
| it for the contractors (edit: cement producers) buying from you
| instead of others? I get the environmental impact, but my guess
| is they only care if touches their bottom line. Will it be
| cheaper, either in raw price or because of green incentives etc?
| _joel wrote:
| I thought it was something Kerberos related initially, but
| that's only due to the fairly mundane circles I move in :)
| K5EiS wrote:
| It is norwegian! My SO lived in Heimdal, Trondheim.
| marcuslima wrote:
| I love Trondheim! Gorgeous city
| K5EiS wrote:
| Yeah, just got done with my degree at NTNU. Really enjoyed
| living there.
| marcuslima wrote:
| Nice catch! I'm orignally from Norway. Heimdal is the norse god
| of foresight. Something the world needs in buckets when it
| comes to climate change.
|
| Our experience so far has been that the environmental angle has
| been sufficient to persuade. Cement companies are in a bit of a
| bind given the attention to their sustainability efforts.
| However we're pitching ourselves as a cost competitive
| solution. Depending on geography we'll be able to positively
| affect their bottom line through the carbon credits system.
| Under the European ETS for example, they reward companies that
| reduce emissions (https://carbonmarketwatch.org/wp/wp-
| content/uploads/2016/11/...)
| matsemann wrote:
| Cool. Yeah, maybe the old way of making cement will be too
| expensive in the future compared to a greener way. Good luck
| with your first mover attempt!
|
| Another curious question: Do you make an "actual" limestone,
| or what is the final output? A rock, chalk, mudlike or
| something?
| marcuslima wrote:
| Thanks! Yeah, we think it will be. But more importantly,
| the old way isn't a viable option. It's effectively off the
| table. Sweden has already banned mining of limestone
| (https://www.ribaj.com/products/cementa-limestone-mine-
| suspen...) The product comes out as a really finely ground
| powder
| cerved wrote:
| to be specific, an application was not approved and the
| reason the court gave was insufficient proof that
| continued mining wouldn't effect the local groundwater
| marcuslima wrote:
| Yes, thanks for clarifying
| jedberg wrote:
| > Nice catch! I'm orignally from Norway. Heimdal is the norse
| god of foresight.
|
| I figured you guys just like Marvel movies. :)
| marcuslima wrote:
| They're pretty good too ;)
| bernulli wrote:
| I think it's a bit late for foresight, maybe Cassandra (is
| there a Norse equivalent?) is a more apt description of the
| situation we are in ;-)
|
| Good luck, great idea, hope it works out!
| abfan1127 wrote:
| are you capturing Carbon or CO2? It seems we've released Carbon
| from prehistoric oil, but not O2. what is the consequence of
| capturing O2 as well?
| pabs3 wrote:
| Your post mentions desalinated water, how are you dealing with
| the desalination byproducts (very salty water I assume)?
| [deleted]
| j-bos wrote:
| Excited to see new implantations in concrete! Given the low
| lifespans (and thus higher environmental costs) of reinforced
| concrete, what are you thoughts on basalt rebar? Are sustainable
| reinforcement methods on your radar?
| marcuslima wrote:
| All intiatives worth doing. Can't tackle this problem from too
| many angles at this stage. Alternative reinforcement would be
| compatibel with our solution in any case
| tixocloud wrote:
| This is a really interesting project/opportunity. Does the
| trapped CO2 become permanently trapped? And how do you guys
| envision "integrating" into the existing processes to offer them
| the solution? Is it a fairly heavy lift?
| maCDzP wrote:
| Is the capture a chemical or biological process?
| colinprince wrote:
| Missed this thread till now. Very intriguing product!
|
| Is there a use for your synthetic limestone in the agricultural
| sector? E.g., for soil treatment?
| filleokus wrote:
| Really cool! Looking forward to follow your journey.
|
| I understand that you might not be ready to share numbers, but
| you mention both hydrogen and desalinated water as byproducts,
| which both are quite energy intensive to produce. Any chance to
| give a hint along the lines of: X kWh of power
| + sea water + sorbent (consumable?) => Y% CaCO3 + Z% H2 + W% H2O
|
| When at scale, will your synthetic limestone be much more
| expensive than mined limestone or roughly the same?
| marcuslima wrote:
| Our synthetic limestone will be on par with mined limestone. At
| scale when accounting for the higher calcium content per tonne
| and value of carbon we expect to be cheaper even than mined
| limestone.
|
| You hit the nail on the head there. The most important cost
| factor is energy. We're looking at <3MWh/tonne of CO2 removed.
| Somewhat higher than some competing DAC companies that claim
| 1.5-2.5MWh. But these guys have the added cost of finding
| permanent storage of their gaseous CO2. Cost estimates for
| this, at scale, are as high as $100/tonne
| didip wrote:
| Is the price per kg competitive to the conventional cements?
| marcuslima wrote:
| yep!
| chana_masala wrote:
| Have you done any research into alternatives to concrete? My
| limited understanding is that besides the actual production
| process of concrete releasing CO2, the increasing surface area of
| the Earth covered in concrete is amplifying the effects of global
| warming. So maybe this process is carbon neutral in the
| production sense, but remains a net negative? I'm curious about
| your thoughts there.
| notinventedhear wrote:
| Congrats on the launch!
|
| Just curious if you're interested in an incubator? We went
| through the Oxford Foundry[1] last year and would highly
| recommend it.
|
| [1]https://www.oxfordfoundry.ox.ac.uk/
| zestyping wrote:
| This looks exciting! You mentioned building a demo plant that has
| 1 tCO2/year of capacity, which you plan to scale up to 300
| tCO2/year. What is your estimated cost for building a plant, per
| tCO2/year of capturing capacity? (As opposed to the ongoing cost
| per tCO2 captured, which sounds like it will be somewhere around
| $100/tCO2?)
| autopoiesis wrote:
| What are the inputs and byproducts of the manufacturing process
| for your proprietary sorbent, and what are their environmental
| impacts, if any?
| robinsoh wrote:
| I am curious what is your take on Davidovits geopolymer based
| carbon capture. I believe he was using kaolinite as the starting
| point with alkali activation. A second approach was using fly ash
| and silica flume/slag, byproducts of power plants and steel
| production.
| skohan wrote:
| Very cool project!
|
| A couple questions:
|
| 1. How does your synthetic limestone compare to natural
| limestone? Are there any important performance differences in
| terms of the material properties of the resulting concrete?
|
| 2. What are the biggest bottlenecks/obstacles in terms of scaling
| this to the point it could replace a significant portion of
| natural limestone used today?
|
| Edit: do you have any blog posts/more information about what
| you're doing? I would love to share this around, but unless I'm
| missing it your site is very light on details.
| marcuslima wrote:
| Thanks! 1. We are entering the product testing stage with our
| cement producing parnters in the next few months, so I'll have
| a better answer for you then. But from a chemical composition
| point of view, our product is purer than mined limestone and so
| should perform better. 2. Biggest bottleneck from our
| perspective is nailing planning permission to build our plants
| quickly enough to supply cement producers.
|
| Unfortunately no blog post or anything like that just yet.
| Website is very light on details for now, we haven't
| prioritised updating (+ some patent considerations).
| acomjean wrote:
| > 2. Biggest bottleneck from our perspective is nailing
| planning permission to build our plants
|
| How do you get permission to mine seawater? Its kinda of a
| weird question and I imagine its very country dependent.
|
| Very intersting project.
| nine_k wrote:
| I suppose it must be similar to permissions to use seawater
| as coolant, or for producing freshwater from it.
| skohan wrote:
| Yeah cool! If you have a twitter or any other way to follow
| you guys I would love to - I work at a sustainability-focused
| startup and I know a lot of people who would be interested in
| this, and not all of them would be in the HN audience.
| moralestapia wrote:
| Could you share more details about your startup?
|
| If you wish to do it privately, check links at my bio.
|
| Best!
| marcuslima wrote:
| Will DM you
| marcuslima wrote:
| Love the enthusiasm to share! This is a bit of a coming out
| party for us, so not much out there in the way of public
| information. We'll add to that as it comes higher on the
| list of priorities
| mikob wrote:
| Sounds promising! I have noticed companies with environmental
| impact have disproportionately more success in crowd-funding.
| Many non-institutional investors (like myself) put their money in
| ideas that are good for the world - almost like charity. Perhaps
| you will consider raising funds and spreading the word using a
| crowd-funding site such as https://www.startengine.com/explore
| marcuslima wrote:
| I love the idea of crowdfunding! Definitely something we'll
| look into down the line.
| reilly3000 wrote:
| This is great to see and I hope it's a very successful
| enterprise! Since this is a novel enterprise and I think there is
| some appeal among architects and consumers, it may be worth
| carving out some marketing moat with a registered trademark and
| perhaps an icon. While they aren't your customer, the whole
| supply chain would be pleased to use your materials in their
| projects- so anything you can do to help them brag ultimately
| helps you.
| marcuslima wrote:
| Absolutely! We're in the early stages of developing an idea
| like this. We're working with a californian construction start-
| up to reduce embodied carbon in their building materials.
|
| We've also thought about working with some big name companies
| like Apple, Amazon, big name hotels etc. to build a carbon
| neutral office/store/hotel. Haven't been able to reach the
| right people here yet though. Any intros/suggestions are
| appreciated!
| lifekaizen wrote:
| I can see the appeal but would recommend against pursuing
| large name brand companies at this point. If your solution
| does what you say, that's already incredibly novel and
| interesting to the right buyers; people are seeking these
| solutions out. The real question will be: what's the cost? So
| scaling and cost reduction is where I'd focus. It's likely
| non-trivial to go from 1 ton, to 1000, to 1 M.
|
| If you're looking for a novel way to generate excitement, how
| about the X-Prize?[0] You're doing a demo of "1 tonne of CO2
| per year", that's enough to enter, and entering is enough to
| tell investors. Doing well could provide dilution free
| capital, technical validation, in addition to free publicity.
|
| [0]: https://www.xprize.org/prizes/elonmusk
| marcuslima wrote:
| Great thoughts! Our strategy so far has mainly been focused
| on targeting large producers of cement and glass. We're in
| the process of signing LOIs here. Agreed that getting
| scaling right will be the big challenge
|
| X Prize is on our radar, only a shame we mised the cement
| specific one. Though the dollar value on this one is
| certainly better
| m___ wrote:
| "Making money" is the biggest Co2 unleashing endeavour by far.
| Trapping science in hic-ups bursts in a linear narrative is not
| explanatory. Be well, the World is dumbed down enough to take
| your desires for solutive. You might reach for local fame and
| hoaxy glory. The Co2 in your case is released by your approach.
| rout39574 wrote:
| How many orders of magnitude separate your current cost per ton
| of limestone from the popular status quo methods?
|
| You're talking about ancillary products and regulatory credits,
| which is a fine business model; but I'm asking about the core
| industrial process. Trying to get a sense of how much more
| efficient your scale-up needs to be, before your process is in
| the black.
| marcuslima wrote:
| Our current cost per tonne is in the same order of magnitude
| when including the carbon value from the European ETS. The key
| success criteria for making large plants profitable will be
| connecting to cheap electricity at <$50/MWh we're in the black
| galacticdessert wrote:
| Cheap green electricity at less than 50 $/MWh should not be a
| problem, most PPAs are already getting signed at costs
| substantially lower than that.
| rossjudson wrote:
| Make crypto mining illegal. Boom! Do something useful with
| the energy instead, like cut carbon dioxide.
| nobodyknowsyoda wrote:
| What is the current price of carbon credits in the ETS? I am
| from the USA / am dumb, so don't know how to find it
|
| Also good read for everyone:
| https://www.gatesnotes.com/Energy/Introducing-the-Green-
| Prem...
| marcuslima wrote:
| Haha gotcha, European ETS is on a bit of a tear at the
| minute. Has risen to ~$70/tonne CO2
| lifekaizen wrote:
| The World Bank has a great resource here which lists out
| pricing for emissions trading systems (ETS) and carbon tax
| by country.[0] (Map & Data > Price > Type of Instrument).
| Highest carbon taxes are $100+ / ton (Sweden, Switzerland,
| Lichenstein), high initial value for trade is about $50
| (EU, Switzerland).
|
| We are a bit behind in the US in credits or taxes, we are
| now treating the social cost at $51, but not using that for
| tax or trade policy.[1]
|
| There's one more number that is useful to get a numerical
| sense of the costs: $258 / ton, an estimate of the actual
| cost to society. [2]
|
| [0] https://carbonpricingdashboard.worldbank.org/map_data
| [1] https://www.scientificamerican.com/article/cost-of-
| carbon-po... [2]
| https://www.nature.com/articles/s41467-021-24487-w
| marcuslima wrote:
| That estimate of cost to society should tell us something
| when contrasted with the actual prices being levied right
| now. Hopefully we'll get closer to that number
| eventually!
|
| Hopefully the US does this: https://news.climate.columbia
| .edu/2021/05/06/proposed-45q-ta...
| rout39574 wrote:
| What electricity sources have you identified as acceptable
| for this? Proximity of e.g. hydro to an ocean seems like a
| small set of sites. :) A naive glance suggests that solar
| capacity factor of 25% is going to put that particular source
| out of your budget.
| twic wrote:
| There's quite a lot of wind power available at sea.
| marcuslima wrote:
| Convenient that ;)
| LeifCarrotson wrote:
| One fortunate aspect of electricity is that it's easy and
| efficient - on the order of 2-6% losses due to transmission
| for hundreds of miles - to transport.
|
| Whether your country has invested in renewable sources like
| hydro plants and associated high-voltage, long-distance
| transmission lines is what matters. The geography of
| whether hydro plant is near the coast or not is of less
| importance than whether it exists or not!
| uranium wrote:
| +1
|
| Can you handle intermittency in your power, or do you need
| to run continuously? What capacity factor do you assume in
| your cost model?
| marcuslima wrote:
| That's actually the trickiest part of the engineering,
| but we've managed to make it directly compatible with the
| an intermittent energy source like solar and wind
| go_elmo wrote:
| How "flexible" is the production? I mean during peak-sunny
| hours the price of electricity is well below that mark in
| some regions of europe? And would it e.g. make sense to scale
| up in a very sunny region & produce your own power? Last
| question: Do you need electrical power or heat? If latter,
| would a more efficient thermo-solar power plant make sense?
| Best of Luck! :)
| f6v wrote:
| > And would it e.g. make sense to scale up in a very sunny
| region & produce your own power?
|
| It's an interesting point. The most sunny region might be
| not the target market. Then you need to factor in the CO2
| emissions arising from the transport to consumers.
| Jolter wrote:
| This kind of scale would require establishing factories
| all over the world. Every feasible region in every
| developed country.
| marcuslima wrote:
| Yep! It'll be quite a journey to get there
| go_elmo wrote:
| True and interesting point - but if you're able to
| produce as cheaply to "push out" dirty competitors and
| still have a net saving when including transport, it
| would still make sense I suppose. Also, there are always
| relatively close sun intensive regions near major
| customers: mongolia / tibet china, north africa europe &
| middle east, the US has its own deserts...
|
| also, transport is a minor fraction compared to the net
| saving
| marcuslima wrote:
| Absolutely, CO2 emissions from transport isn't much of an
| issue compared with the saving. Hopefully someone like
| Remora will crack that problem anyhow. We'll most likely
| need to build our plants closer to where the market is
| though, to limit the financial cost of transportation
| marcuslima wrote:
| Thanks! ABsolutely, looking at optimizing time of day we
| operate will be important. As grids become more dominated
| by renewables a solution like ours will be able to help
| stabilize acting as a electricity sink when the wind is
| blowing too hard or the sun too strong, taking advantage of
| lower power prices at these times
| nightshift1 wrote:
| You should come to Quebec (Canada). The electricity is cheap
| and 99% from renewables.
| https://www.hydroquebec.com/business/customer-space/rates/
| uranium wrote:
| Will you be able to complete on cost without carbon credits,
| at scale?
| marcuslima wrote:
| We're competitive at scale. This does require us to hit our
| CAPEX targets and to capitalize on cheap renewable sources
| of electricity that are becoming prevalent
| gwbas1c wrote:
| > Concrete is responsible for 8% of global CO2 emissions. Cement
| is usually made from mined limestone. [Snip] We make synthetic
| limestone using atmospheric CO2, [snip] when [snip] used to make
| cement, [snip] (it) is carbon neutral.
|
| You should put that (slightly edited) paragraph on your home
| page. I looked at your home page first and didn't understand what
| you did until I came back here.
|
| Best of luck!
|
| (Btw: Try to avoid using the passive voice.)
| danieka wrote:
| From my limited understanding this seems really impressive!
|
| I immediately associated this to possible disruption in the
| cement supply chain that's about to hit Sweden. Cementa, which
| produces about 75% of Sweden's cement, will no longer be allow to
| mine limestone on Gotland. Their permit was due to be renewed but
| due to the low quality of their environmental impact study the
| court was unable to determine if the mining might impact the
| local residents groundwater. So just a week or so ago a Swedish
| court decided Cementa muts cease mining operations some time in
| October. And as I said this mine/factory produces 75% of Sweden's
| cement. So there are more problems with the current way of
| producing cement than just CO2.
|
| Most probably there will be a limestone/cement void in Sweden
| that needs to be filled, and I'd rather have you doing it than
| some new limestone mine. Best of luck to you!
| marcuslima wrote:
| Yes! This is awesome, I saw this a couple weeks back. We're
| trying to get in touch with Cementa, but it seems Scandinavian
| holidays are getting in the way so far. Definitely an ideal
| place for us to start. That plant does 70% or so of Sweden's
| cement consumption
| ccr-yc wrote:
| Taking bicarbonate to carbonate releases about 0.8 moles of CO2.
| This has the opposite effect of what you are intending. See the
| below link for a discussion of the mechanism for how taking
| carbonate (i.e. limestone) to bicarbonate sequesters carbon.
| Please don't just run this reaction in reverse. That's almost as
| bad as our current process for making cement. If you're doing
| something different (e.g. adding a counterion to replace
| calcium), then where does this come from?
| pankajdoharey wrote:
| It seems what they do is Ocean Water + Sorbent -> Leaches
| Carbonates for use in Cement -> Heated in Kiln -> Releases C02
| -> Captured and redissolved in Ocean water. This still has to
| be proved how to reabsorb such large amounts of c02 in ocean
| water.
| galacticdessert wrote:
| Absorbing large amounts of CO2 happens every second since 2-3
| centuries at this point, and is the main driver of ocean
| acidification and subsequent coral bleaching, loss of
| wildlife, etc. If the mentioned process could "recycle" the
| CO2 needed for lime production, then it could be a big win
| for a very hard to decarbonize sector.
|
| What is still to be checked is how more expensive this lime
| will be, and how it will stack up compared with traditional
| limestone+carbon tax
| thatcat wrote:
| Seems the co2 binds the proprietary alkaline sorbent when
| released from the Ca/Mg.
| scythe wrote:
| What's your primary source of calcium? Can you write your process
| as a chemical reaction equation? Would that compromise some kind
| of trade secret? E.g.
|
| CaSiO3 + NaCO3 >> Na2SiO3 + CaCO3
| immmmmm wrote:
| (former) cement scientist here.
|
| you say we are "addicted" to cement/concrete which is correct,
| but then propose more cement? i get we might need cement here and
| there for energy transition and might need your tech. but isn't
| using less cement a better/complementary approach?
|
| im addicted to tobacco, not sure natural tobacco is my best bet.
|
| at a time where half of the world is burning, do we need more 10
| ways bridges for huge cars?
|
| how do you tackle the worldwide sand shortage problem?
|
| does your tech solves the issue that comminution (grinding) of
| clinker is one of the biggest electricity consumers worldwide?
|
| how does that scales up, how long to deploy? what are the
| consequences (please be honest) to marine life, knowing that most
| kelp forests/corals are now gone/bleached?
|
| how does your tech tackles the massive corruption problems that
| come with concrete?
|
| thanks in advance
|
| edit: don't take it badly, your tech looks promising on paper.
| quickthrower2 wrote:
| One startup cannot solve all the problems right?
|
| Also I like solutions that don't rely on people changing their
| habits, because they are most likely to work.
|
| The alternative to tobacco is no cigars or cigarettes, the
| alternative to cement is not simply no buildings, no railways,
| no roads, no infrastructure.
| immmmmm wrote:
| we are building out of clay, stone and wood for a long time.
| we are only using concrete because it's cheap and convenient.
|
| still not convinced of hydrogen for steel rebar production
| also.
| ccr-yc wrote:
| https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/1999...
| therealplato wrote:
| Congratulations. Curious whether the process remains carbon-
| neutral after counting the carbon footprint of the renewable
| sources themselves
| marcuslima wrote:
| Yes! It's true wind, and solar especially, have a small carbon
| footprint associated with production, but our process is carbon
| negative enough to more than compensate for it
| jacknews wrote:
| First step in this?
| https://en.wikipedia.org/wiki/The_Millennial_Project
| marcuslima wrote:
| Haha, definitely. Got any links to Elon Musk? ;)
| cocoflunchy wrote:
| I guess you can get in touch by participating in
| https://www.xprize.org/prizes/elonmusk :)
| marcuslima wrote:
| Haha, fair point ;)
| brilee wrote:
| I did some lengthy analysis behind the chemistry / economics and
| wrote it up here.
|
| https://www.moderndescartes.com/essays/carbon_neutral_concre...
|
| TL;DR: ignoring all sources of overhead/inefficiency and purely
| on consideration of thermodynamic costs, $70 of electricity can
| generate $100 of lime, $300 of chlorine gas, and $75 of hydrogen
| gas.
|
| Much more details on the chemistry and economics in the blog
| post...
| go_elmo wrote:
| Thanks for the analysis, interesting to read! What about the
| lime-burning for cement, does it imply "only" net-carbon
| neutral as all the captured carbon is released upon cement
| production? And what about iron smeltering? I suppose most
| carbon is also released in that process?
| marcuslima wrote:
| Same idea for iron!
| dang wrote:
| Wow, that's the most in-depth response to a Launch HN I've ever
| seen.
|
| This is probably the most substantive Launch HN thread (I mean
| of the official YC startup launches at
| https://news.ycombinator.com/launches) that we've yet seen. And
| it was very little work to put together.
| marcuslima wrote:
| Agreed!
| brilee wrote:
| The secret is apparently to be slightly cagey about your tech
| and nerd snipe half of HN into trying to figure out if your
| thing actually works or not...
| rossjudson wrote:
| The other secret is to not be using investor money to pay
| low wage gig workers while you build out a "platform" for
| the future when you take all the business from everyone
| because they are too dumb to possibly compete with you.
| marcuslima wrote:
| Impressive analysis! Missed out on a couple details, but I'll
| take that as a thoroughly researched/analyzed endorsement. Most
| importantly, we'll be scaling up a lot faster. Our current
| 1t/yr is just a demo. Our current roadmap is scaling up to a
| 300t/yr pilot in the next few months before setting up building
| a commercial plant (10kt+) in the second half of next year. Any
| chance we can poach you from Google? ;)
| m12k wrote:
| What's the status on your current 1t/yr demo? (i.e. is it
| fully operational?) What did you learn from it and what are
| the technical challenges to scale it up to bigger plants?
| thereisnospork wrote:
| Some comments and expansion on your analysis, which I enjoyed
| reading and provided a nice excuse to dust some mental cobwebs.
|
| I'd also like to clarify up front that I'm limiting my analysis
| to the proposed electrochemical mechanism, and have no
| information on the specifics of Heimdal's proposed
| implementation - which may vary significantly and materially:
|
| The theoretically minimum electrical energy input (often) winds
| up being set by one of the reaction intermediates, rather than
| the overall reaction enthalpy. Typically these analyses are
| done via determining the corresponding half cell potentials,
| then counting electrons and computing power via P = IV.[0] So
| we only need to consider H2O (and its dissociation -0.83[1])
| and Cl- to Cl2 at 1.36). That sums to approx 2.19V for the
| cell, and 2 electrons to do 2H2O + 2Cl- -> H2 + 2OH- + Cl2.
| That the formed OH-'s pair with Ca2+, and/or CO2 is immaterial
| to the theoretical electrical efficiency of the cell.
| Accordingly, the cell energy requirement is on a molar basis
| identical to the chloralkali process. The only difference is
| the presence of 2Na+ vs. Ca2+.
|
| Less concretely the lower reactant concentrations have two
| specific negative effects: Cell potential is adversely affected
| (per the Nernst equation) and Cell current can be adversely
| affected if/when depletion occurs. At 0.01M of Ca2+, vs. 6+M
| Na+[2], current densities could be 1-3 orders of magnitude
| lower. Cell count (CAPEX) is inversely proportional to current
| density.
|
| Ultimately making CaCO3 this way (and CaO) winds up
| substituting a 400$/tonne product in NaOH for an approx
| 40$/tonne product in CaCO3. It is a very technically feasible
| approach for turning $$$ into sequestered carbon via non
| emission from natural limestone.
|
| The analyzed approach reminds me a lot of Calera, who had an
| apparently similar electrochemical approach to CaCO3.
|
| [0]Not that it can't be done from Gibb's energies, indeed the
| standard potentials for a reaction can be computed from the
| delta Gibbs, but the specific species the electrons are being
| pulled from/pushed into matters. Phrased a different way:
| electrical energy and overall reaction enthalpy are not
| necessarily fungible. e.g. (at a simple level) the reaction of
| CO2 with Ca(OH)2 doesn't affect the electrical energy
| requirement, nor does CaCO3 --> CaO because neither reaction
| involves electrons. Any exotherm just winds up 'wasted' as
| heat, instead of lowering the electrical demand.
|
| [1]Per 2H2O + 2e- --> H2(g) + 2OH-(aq) #6.8.11
| https://chem.libretexts.org/Courses/Mount_Royal_University/C...
|
| [2] Saturated near room temp, don't have a better source handy.
| brilee wrote:
| Thanks for the comment, I also had to dust off some mental
| cobwebs for this analysis :)
|
| You're pointing out the crux of the issue: "Ultimately making
| CaCO3 this way (and CaO) winds up substituting a 400$/tonne
| product in NaOH for an approx 40$/tonne product in CaCO3."
|
| I calculated that Heimdal's process has 7x reality factor
| overhead, whereas chloralkali has 2x reality factor. This is
| seemingly in opposition to your statement. I think the diff
| comes from considering all the other energetics -
| precipitation of CaO from the hydroxide is thermodynamically
| quite favorable, reducing the overall theoretical cost by 65%
| relative to the chloralkali process. So to the extent that
| Heimdal can usefully harness that energy gradient, that's the
| difference.
| thereisnospork wrote:
| >This is seemingly in opposition to your statement. I think
| the diff comes from considering all the other energetics -
| precipitation of CaO from the hydroxide is
| thermodynamically quite favorable, reducing the overall
| theoretical cost by 65% relative to the chloralkali
| process. So to the extent that Heimdal can usefully harness
| that energy gradient, that's the difference.
|
| I guess the crux of my argument is that it is impossible[0]
| to capture the energy from CaO precipitation. E.g.[1] one
| has to spend 2J of electrical to create the hydroxide in
| Ca(OH)2, but the 1.5J get released on precipitation of CaO
| comes as heat[2], rather than a reduction in energy input.
|
| So, in summary, Electrochemical CaCO3 would have
| [approximately] equal theoretical electrical demand to
| chloralkali and, to borrow your term, a higher reality
| factor overhead[3], to make a product an order of magnitude
| cheaper than NaOH.
|
| [0]For a loose definition of impossible, to be fair
| reality's never quite so black and white.
|
| [1]Made up numbers.
|
| [2]And heat in sub-boiling water is not useful for doing
| work.
|
| [3]I broadly agree with your position on reality factor
| overhead, just made less of an emphasis on it trying for
| 'equivalent but worse and creates less value'
| blacksqr wrote:
| According to their web site, one of their premises is that
| renewable electricity is now cheap and plentiful. If that's
| so, I'm led to wonder if there is a more direct way to
| reduce CO2 emissions in cement manufacture, namely, use
| resistive or carbon-arc heating to fire the ovens, thus
| replacing fossil fuels in the manufacturing process.
|
| Sorry I don't have the chops to work out if that's
| economically feasible.
| coryrc wrote:
| The thing you are firing in the oven (limestone) releases
| CO2. Fossil fuels aren't the only source of CO2.
|
| We need zero CO2.
| blacksqr wrote:
| > The thing you are firing in the oven (limestone)
| releases CO2.
|
| I'm aware of that. There are two main sources of CO2 in
| cement manufacture: the calcium carbonate raw material,
| and the fossil fuel required to cook the raw materials
| into clinker. Heimdal only deals with one. The questions
| I'm interested in are which source contributes more CO2
| and which can be most economically eliminated.
|
| > We need zero CO2.
|
| Agree, but Heimdal won't get us there. We'll either have
| to find a replacement for cement, or devise a practical
| method to convert CO2 waste to something benign, like an
| improved Bosch process.
| thinkcontext wrote:
| Interesting, thanks. The chemistry you discuss sounds a lot
| like this
|
| Rau, G.H., Willauer, H.D. & Ren, Z.J. The global potential for
| converting renewable electricity to negative-CO2-emissions
| hydrogen. Nature Clim Change 8, 621-625 (2018).
|
| https://www.nature.com/articles/s41558-018-0203-0?WT.feed_na...
| galgalesh wrote:
| Could it be profitable to take advantage of the overabundance of
| renewable energy during certain periods of the day? Or does
| profitability require running the process 24/7?
|
| I'm thinking, for example, whether this could sink some of the
| overabundance of solar energy in places like California.
| marcuslima wrote:
| Absolutely! This is a big part of our thinking for how this
| integrates with future energy systems based on renewables. We'd
| offtake cheap electricity when oversupplied, like in California
| right now
| Mizza wrote:
| Cool initiative!
|
| Can we talk turkey? What's your cost of capture per ton, and how
| do you scale from one ton to two billion tons?
|
| The average emissions per capita per person in the US is 15 to 20
| tons per year. You're building a plant that can capture 1 ton per
| year.. so 1/15th of a single person. How does this make a dent?
| DOsinga wrote:
| Yeah, I was wondering about that too. Is the 1 tonne a typo?
| Even for a demo product it doesn't seem all that much.
| marcuslima wrote:
| We're building it out to ~300 tonnes/year in the next few
| months. Our commercial partners don't need more than 20-30kg
| of product for initial testing and then just a few tonnes to
| run industrial testing.
| marcuslima wrote:
| Thanks! You're right the current version is pretty small. The
| demo we're building is just about making enough product for our
| commercial partners to test in their facilities. That way they
| can confidently sign binding purchase agreements that we'll
| leverage to build commercial scale facilities. We're aiming to
| build our first commercial scale plant next year. Since our
| product is chemically identical to mined limestone, only much
| more pure we're confident we have a compatible product!
| komali2 wrote:
| Aaaah so cool. More and more I'm thinking the largest impacts
| seem to be happening "in the real world." As a software engineer
| lately I've been feeling kinda.. pointless. Like we've made some
| cool apps out here for identifying and tracking illegal factories
| here in Taiwan, but now we have a backlog of thousands, and the
| "real work" is happening in the bureaucracy and paperwork that
| eventually results with cops being sent to the factory to deliver
| court paperwork and shutdown / modification orders, and that
| feels real-world and unfixable by me.
|
| Kinda a ramble as my friends and I are actively talking about
| this right now in regards to this thread, but I'm curious how
| other HNers feel about this. Like when I was at Electric Imp, the
| real magic seemed to happen when the soldering irons got busted
| out. Here in Taipei I asked my buddy who's driving all the
| lamborghinis, and he said "just regular entrepreneurs,
| import/export types." I'm not money-motivated but I have been
| feeling I guess "left out?" I'm thinking about all those
| engineering projects I hear about out in Africa where they make
| super efficient mini stream turbines, or float wifi balloons.
| Feels like the good shit happens IRL.
| blacksqr wrote:
| Sounds similar to seacrete.
|
| https://en.m.wikipedia.org/wiki/Biorock
| jvalencia wrote:
| I've been recently thinking about desalinization and what people
| could do with the excess salt rather than re-releasing it. It
| makes me wonder if you couldn't bake the salt into cement thereby
| killing two birds with one stone, so to speak.
| marcuslima wrote:
| We actually use concentrated brine in our solution!
| frellus wrote:
| When I saw this the article title being about cement and carbon,
| I got excited that someone invented a way for cement to better
| absorb heat and solar radiation.
|
| I have to imagine global temperatures are affected by the
| reflection of cement quite a bit. Blacktop certainly returns heat
| into the air, as do roofs, but I would guess so does most cement
| -- why does no one talk about it? Soil aborbs, plants absorb,
| solid cement reflects, no?
| drdeca wrote:
| I'm confused; wouldn't you want it to reflect the solar
| radiation, not absorb it? The energy has to go somewhere!
| Unless the energy is going into something else, like increasing
| some chemical potential energy, or producing electrical power,
| or something, if it is absorbed, it is as heat. While, if it is
| reflected, (some proportion of) it may leave the earth as
| light.
|
| I guess something which might help is if you could change the
| wavelengths that went out from it to be ones that would be more
| likely to leave earth rather than being absorbed/reflected by
| the atmosphere? But I don't know if that can be done
| efficiently enough to not produce more heat in the process of
| changing the wavelengths than just reflecting it would, if it
| is even possible.
| marcuslima wrote:
| Some exciting innovations in this field in terms of using
| white paints to reflect away light and reduce surface
| temperatures!
| Aachen wrote:
| Did I correctly understand the idea if I summarise the product as
| similar to Climeworks, capturing atmospheric CO2 (indirectly
| through the ocean, same thing in the end), but with the
| difference that you can sell the resulting product as cement
| ingredients (plus some byproducts) rather than it being just
| stored away like Climeworks does?
|
| If this is (roughly) correct, what price point per ton of removed
| CO2 are you at today, assuming the cement ingredients can be sold
| at an optimistic price point? I'm currently with Climeworks but
| it's prohibitively expensive to remove all unavoidable emissions
| that I cause by living a normal life today, so my subscription
| doesn't cover all emissions yet and I would love to.
|
| Finally, I don't see a way to buy anything on your site, or even
| a waiting list. Is there some call to action, like if I were a
| cement producer could I buy your product today? Any plans to
| offer CO2 removal to consumers? Or anything else people or
| businesses can buy at the moment?
| marcuslima wrote:
| Yeah, that's the core of it. Climeworks absorbs CO2 on their
| amine solid sorbent surface before releasing it by heating up
| the sorbent to prepare it for a new round of CO2. That CO2 then
| needs to be stored somewhere. I'm not familiar with the inner
| workings of Climeworks, but if I were there that would be what
| concerned me the most. I know they're testing a mineralization
| solutipn with Carbfix in Iceland that could be promising, but
| expensive. We're not at sufficient scale to offer credits to
| consumers. but this could be on the agenda in a few months. As
| for cost per tonne this depends a lot on the commercial
| arrangements we have in place. More meaningful is the energy
| consumption per tonne which is <4 MWh/ tonne. This will be
| reduced to 3MWh/tonne. Based on current commercial
| conversations we're expecting a CO2 price below $50/t for our
| first plant
| Aachen wrote:
| $50/t sounds amazing! That would be a price point where I
| could offset 100% of unavoidable CO2e emissions quite easily.
| Too bad it won't initially be available for consumers, but
| I'm very much looking forward to seeing where this goes :)
| noahth wrote:
| This sounds really cool, and I hope it goes well. We need to work
| every angle we can to address climate change, and test as many
| ideas as necessary to get there.
|
| My issue with this post is the claim that you will be making the
| world's first carbon-neutral houses. I understand the need for
| strong exciting marketing language, but, surely you mean
| something like, first modern Western-style carbon-neutral houses.
| marcuslima wrote:
| Thanks! Yes that's absolutely true, that could've been more
| specific. In the modern world almost every house needs concrete
| for something, at a minimum for the foundations.
| montalbano wrote:
| Looks great, good luck! Question about the seawater aspect, are
| ecological impacts similar to conventional desalination
| processes?
| marcuslima wrote:
| It's actually better, we consumer concetrated brine in our
| process, so we don't create a high local salinity that disturbs
| marine life. In fact we're a pretty good fit for a bolt-on to
| existing RO desalination plants. Let me know if anyone's
| connected to someone at a plant like that!
| sugarkjube wrote:
| Seems to me you're also solving a 4th key problem : what to do
| with renewable electricity when it's being produced but there is
| no demand at that moment.
| frederikvs wrote:
| If I understand correctly, you extract both Calcium and CO2 from
| ocean water, and use this as input for making cement. The ocean
| will absorb the CO2 from the air, and that's a win. Where does
| the Calcium in the oceans come from?
|
| If your process is scaled up massively, will the oceans run out
| of Calcium? Or will they absorb Calcium from somewhere? What
| would that Calcium source be?
| marcuslima wrote:
| Well understood! The ocean is supersaturated in the ocean (ie.
| there is about 20x more of it dissolved than you would expect).
| In fact it's the single largest deposit of calcium in the
| world. Risk of running out is zero. Calcium in the ocean comes
| from dissolved limestone (this does not emit CO2)
| hedora wrote:
| What sort of waste water do you produce? What is the local
| ecosystem impact?
|
| Edit: Also, it's great that your de-carbonating the ocean as
| part of this project. Ecological damage to the ocean is out
| of sight, and usually out of mind.
| marcuslima wrote:
| All 'waste' we produce we either consume in our process or
| we're able to sell as a commercial product!
|
| Not bad tackling ocean acidifcation to boot
| radicalbyte wrote:
| I was just about to make this point: as I understood it,
| ocean acidification is a massive environmental problem.
|
| Would your process reduce the local acidification
| significantly? Could there actually be a win-win
| situation here deploying around coral reefs? Especially
| given that such reefs are found in countries with massive
| solar potential (i.e Australia).
| pabs3 wrote:
| How will reducing the amount of dissolved calcium and CO2 in
| the ocean affect organisms like shellfish and crabs. Could
| there be local zones around your extraction points where
| these organisms can no longer produce shells?
| marcuslima wrote:
| The ocean is 20x supersaturated with calcium and is
| constantly being replenished by geological stores of the
| stuff coming in through rivers. As long as the ecosystem
| remains supersaturated this shouldn't be a problem for any
| marine life. Though a slight dislcaimer there is i'm not a
| marine scientist!
| hippari wrote:
| I think the diffusion rate of Ca and CO2 is also
| important. Even though the ocean is supersaturated
| *globally*, the local area around your plant might not
| have enough concentration. Hope you can get someone to
| check that.
|
| Might have to spread your plants across multiple regions,
| or place it around somewhere with low impact to marine
| life I think.
| sgc wrote:
| They can reduce that risk by having very long tubes that
| can be re-positioned from the surface using ships to take
| water from different locations while the currents
| replenish the other locations. Or just have several tubes
| to draw from. Like rotating a pasture. No doubt they will
| need to actually monitor and plan for this or they will
| likely create a disaster.
| frederikvs wrote:
| Could you elaborate on how dissolved limestone does not emit
| CO2? Limestone is CaCO3. The calcium gets dissolved, ready to
| be used by your process. The Oxygen, I don't care much
| whether it stays in the water or goes into the atmosphere.
| Where does the carbon go, if not into CO2?
| marcuslima wrote:
| That's part of the CO2 saturation of the ocean. So when we
| remove that dissolved CO2 that equivalent amount is removed
| from the atmosphere
| foobiekr wrote:
| I have the same question.
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