Carbon-Negative Ironmaking Using Fast Pyrolysis Bio-Oil Gasification | Hacker News Reader

Carbon-Negative Ironmaking Using Fast Pyrolysis Bio-Oil Gasification

charmindustrial.com

15 pointsn2parko8 comments

I wonder how they can write with a straight face this:

> we’re pioneering a way to make iron that’s cleaner, more cost-effective, and American-made.

when the very next sentence is

> Our near-term focus remains coming down the bio-oil production cost curve, making affordable and high-quality carbon removals.

So that "more cost-effective" part in the first sentence is contingent on their huge assumption that they'll be able to "come down the production cost curve" of bio-oil. But then we can make everything more cost-effective in America, if only we come down the cost curve of this and that.

nothing in hardware is cheap until it scales up. in fact, the cost vs. scale dynamics are well understood, see Wright's Law.

the "huge assumption" is our entire roadmap... and the major things that drive cost-down are: (1) increased carbon yield by integrating existing pyrolysis technology, (2) shrinking transport distances by operating pyrolysis near injection wells, and (3) increased throughput by making our pyrolyzers larger. these take time, but are hardly shooting for the moon.

I wish you luck.

Still, I will allow myself to provide some feedback. There's a chance that in your position as the CEO of a startup (and an MIT graduate), maybe not a lot of people are willing to tell you thinks that they think you won't like to hear.

It looks like your business model involves carbon sequestration (you just mentioned here "injection wells", plus it's in the last figure of the article). That means you are proposing a process that smelts iron ore using hydrogen rather than coke. Something like this plant in Sweden [1]. There are two problems now. One is that you are making the assumption that it's quite easy to get such plants in the US too, but the recent history is not very promising ([2], [3]). The second problem is that you are a step ahead of what people want right now. Most people would be happy to make net-zero steel. You are pitching something that is net-negative steel. A lot of people will say it's laudable, but they are not willing to pay extra for that. And if net-zero is their goal, then you need to compete with steam reformation using natural gas. And I don't think this is possible in any scenario, not matter how heroic assumptions about economies of scales or learning curves, or technological improvements one makes.

[1] https://stegra.com/the-boden-plant

[2] https://www.politico.com/news/2024/09/13/steelmaker-biden-cl...

[3] https://www.canarymedia.com/articles/green-steel/ssab-quietl...

Is bio-oil production carbon-negative? How much of bio-oil production uses petroleum oils? I suspect it's non-zero.

Bio-oil production itself has a small amount of net positive emissions associated with it. We also purchase renewable electricity, renewable diesel, etc. to minimize those emissions. The net carbon negativity comes from the balance of the biomass/bio-oil carbon content ending up permanently sequestered deep underground.

> a small amount of net positive emissions associated with it.

I'm very confused. Does that means CO2 capture or CO2 release?

CO₂ is captured from the atmosphere in biomass as C

C in biomass is converted to C in bio-oil, with relatively small release of CO₂

C in bio-oil is injected deep underground for permanent storage/sequestration

If this process had not happened, the C in the biomass would have been entirely emitted as CO₂ through rotting or burning.

Biomass don't have C, it has sugars (C6O6H12, mostly polymerized) and fatty acids (H-(CH2)n-COOH, mostly in oil molecules).

Do you have the chemical composition of the bio-oil? I only found this https://www.music-h2020.eu/publications-reports/MUSIC_D6-1_W... that in page 20 claims 25% of water, so it's a polar solvent like thick sugar syrup, not a non polar solvent like petrol.

That make sense if the graphics are accurate and it's produced from corn stalks (that are mostly cellulose that is polymerized glucose), instead of making it from vegetable oil (that is made of 3 fatty acids and glycerin) and can be transformed in biodiesel by a very different process.

The graphic shows injection after use to make iron. Are you injecting the liquid bio-oil or the CO2 gas after combustion? I very skeptical and expect gas to escape sooner or later.

I think that it's important the "unused carbon" part of the graphic. Here we used to have a big steel mill that had a huge eucalyptus forest to make coke coal (in Spanish) https://es.wikipedia.org/wiki/Aceros_Zapla

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