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.
Launch HN: Heimdal (YC S21) – Carbon neutral cement
91–100 of 227 posts
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#92are 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?
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#93When 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 ce…
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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#94Earlier quoted context omitted.
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. Unfortuna…
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.
Could you share more details about your startup?
If you wish to do it privately, check links at my bio.
Best!
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#95Congrats 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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#96If 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?
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)
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?
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#97Earlier quoted context omitted.
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! :)
> 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.
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
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#98From 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!
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#99Earlier quoted context omitted.
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.
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.
He mentions producing hydrogen as another product, so I would guess they use electricity to turn protons into hydrogen gas, so removing acidity.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#100Earlier quoted context omitted.
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
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.
There's quite a lot of wind power available at sea.