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Launch HN: Heimdal (YC S21) – Carbon neutral cement

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Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#131

Post by marcuslima »

go_elmo wrote: post #28
marcuslima wrote: post #13

Earlier 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

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! :)

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

Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#132

Post by chana_masala »

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.

Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#133

Post by marcuslima »

go_elmo wrote: post #97
f6v wrote: post #50

Earlier 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.

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 ne…

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

Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#134

Post by marcuslima »

twic wrote: post #100
rout39574 wrote: post #43

Earlier 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.

There's quite a lot of wind power available at sea.

Convenient that ;)

Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#135

Post by nightshift1 »

marcuslima wrote: post #13
rout39574 wrote: post #12

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.

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

You should come to Quebec (Canada). The electricity is cheap and 99% from renewables. https://www.hydroquebec.com/business/customer-space/rates/

Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#136

Post by flyingsilverfin »

hwillis wrote: post #107
marcuslima wrote: post #67

Earlier quoted context omitted.

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-…

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 c…

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?

Re: Launch HN: Heimdal (YC S21) – Carbon neutral cement

#140

Post by uxp100 »

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.

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