Very cool! Wish you best of luck!
Launch HN: Heimdal (YC S21) – Carbon neutral cement
121–130 of 227 posts
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#122Very 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 informati…
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…
> 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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#123Is the capture a chemical or biological process?
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#124This 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.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#125This 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…
So true, it's a surprising statistic to most that 8% of global emissions is actually from concrete
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#126Earlier quoted context omitted.
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?
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
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#127Earlier quoted context omitted.
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!
Will DM you
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#128Earlier quoted context omitted.
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?
I have the same question.
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#129Earlier quoted context omitted.
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.
+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?
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
Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement
#130Earlier quoted context omitted.
> 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.
This kind of scale would require establishing factories all over the world. Every feasible region in every developed country.
Yep! It'll be quite a journey to get there