Hi HN, Iâm Marcus, Iâm 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 worldâs oceans become our air contactor.
There are other companies addressing emissions from concrete production, but they donât 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 theyâll 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 theyâre released as their â2050-solutionâ, 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 worldâs 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.
4 years ago by brilee
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...
4 years ago by dang
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.
4 years ago by brilee
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...
4 years ago by rossjudson
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.
4 years ago by marcuslima
Agreed!
4 years ago by marcuslima
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? ;)
4 years ago by m12k
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?
4 years ago by philipkglass
I love your approach but I think that you've made a mistake. $70.00 of electricity at $0.13/kWh is 538 kWh, or 1937 MJ. Hydrogen has a higher heating value of 142 MJ/kg. If you could actually get 36 kg of electrolytic hydrogen from 538 kWh of electricity, that's getting 5112 MJ of chemical energy from 1937 MJ of electrical energy. That can't be done. At first I thought maybe I was overlooking some consumable electrodes in the scheme, but it appears not.
Rule of thumb for electrolytic water splitting is 50 kWh per kg of hydrogen. That would mean about 0.29 as much H2 as estimated in the blog post. If you scale all salable products by 0.29 (not sure if that's sensible since I haven't identified the root error) it would still yield $142 of products from $70 of electricity. And good news there is that industrial scale electricity can be had for well under $0.13/kWh.
4 years ago by nextaccountic
> More than just profitability, can they make a dent in our carbon problem? The scale of our carbon problem is on the order of 30 billion tons of CO2, of which maybe 1 billion tons are due to lime production. Heimdal is currently at the scale of 1 ton per year - nine orders of magnitude away from making a difference. Assuming continuous Silicon Valley ridiculous growth rates of 50% year over year, they will take 50 years to grow to a point where they are actually making a dent in our carbon problem. I wish them good luck.
They don't need to do it all alone. If this idea is solid, a lot of different companies and nations could be doing this.
I'm excited for China to have carbon-neutral cement. If they do, it will probably be of their own making and not tied to this company growth.
4 years ago by danieka
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!
4 years ago by marcuslima
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
4 years ago by hinkley
You know everybody will be working overtime up until then. Extra storage purchased, and possibly discounts to customers for accepting early delivery.
4 years ago by justshowpost
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.
4 years ago by marcuslima
Definitely one for us to get involved with. Unofrtunately it's a 5 year timeline, but that's still not a bad ROI
4 years ago by gwbas1c
> 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.)
4 years ago by frederikvs
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?
4 years ago by marcuslima
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)
4 years ago by frederikvs
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?
4 years ago by marcuslima
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
4 years ago by foobiekr
I have the same question.
4 years ago by pabs3
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?
4 years ago by marcuslima
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!
4 years ago by hedora
What sort of waste water do you produce? What is the local ecosystem impact?
Edit: Also, itâs 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.
4 years ago by marcuslima
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
4 years ago by hinkley
Coral reefs are having trouble with the ph of sea water. If you drop the calcium content then itâs probably more problems for them.
If you pull enough to dissolve more limestone, then theyâre just mining limestone hydraulically, and they are mining it outside of the economic exclusion zone of their own country. This product plan is literally âI drink your milkshake.â
On the plus side Florida will fall into the ocean sooner.
4 years ago by brilee
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?
4 years ago by marcuslima
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.
4 years ago by m12k
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.
4 years ago by _nalply
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.
4 years ago by brilee
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.
4 years ago by twic
He mentions producing hydrogen as another product, so I would guess they use electricity to turn protons into hydrogen gas, so removing acidity.
4 years ago by robinsoh
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?
4 years ago by marcuslima
We make CaCO3, I mention CaO here because that's what cement producers ultimately need. They heat up limestone (CaCO3) to make CaO
4 years ago by undefined
4 years ago by reilly3000
This is great to see and I hope itâs 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 arenât 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.
4 years ago by marcuslima
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!
4 years ago by lifekaizen
I can see the appeal but would recommend against pursuing large name brand companies at this point. If your solution does what you say, thatâs already incredibly novel and interesting to the right buyers; people are seeking these solutions out. The real question will be: whatâs the cost? So scaling and cost reduction is where Iâd focus. Itâs likely non-trivial to go from 1 ton, to 1000, to 1 M.
If youâre looking for a novel way to generate excitement, how about the X-Prize?[0] Youâre doing a demo of â1 tonne of CO2 per yearâ, thatâs enough to enter, and entering is enough to tell investors. Doing well could provide dilution free capital, technical validation, in addition to free publicity.
4 years ago by marcuslima
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
4 years ago by matsemann
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?
4 years ago by marcuslima
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/...)
4 years ago by matsemann
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?
4 years ago by marcuslima
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
4 years ago by bernulli
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!
4 years ago by jedberg
> Nice catch! I'm orignally from Norway. Heimdal is the norse god of foresight.
I figured you guys just like Marvel movies. :)
4 years ago by marcuslima
They're pretty good too ;)
4 years ago by _joel
I thought it was something Kerberos related initially, but that's only due to the fairly mundane circles I move in :)
4 years ago by K5EiS
It is norwegian! My SO lived in Heimdal, Trondheim.
4 years ago by marcuslima
I love Trondheim! Gorgeous city
4 years ago by K5EiS
Yeah, just got done with my degree at NTNU. Really enjoyed living there.
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