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Launch HN: Heimdal (YC S21) – Carbon neutral cement
161–170 of 227 posts
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#162Taking 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 counteri…
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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#163Earlier quoted context omitted.
> 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 energ…
> 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…
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".
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#164I 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...
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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#165I 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...
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.
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...
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#166Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#167How 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.
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
Make crypto mining illegal. Boom! Do something useful with the energy instead, like cut carbon dioxide.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#168Earlier quoted context omitted.
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.
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...
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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#169I 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 yo…
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.
That and lumber is stored carbon while concrete releases CO2 (at least for now).
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#170What’s the greatest challenge or limitation, technology- or business-wise, that your startup faces? If it fails, why will it fail?
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
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?