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Comment by minsc_and_boo | Hacker News Reader

>When used in bioreactors*

When used in a sealed climate-controlled chamber that produces the ideal conditions on land for an aquatic plant specie.

IIRC it's ridiculously expensive to scale algae bioreactors, while trees grow and maintain themselves. I wish algae was easier to scale because it does have great potential.

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My startup is working on novel microalgae photobioreactors - we are raising an angel/pre-seed round right now.

Our system is far more energy and space efficient compared to PBRs and raceways - we do this via a proprietary mechanism that greatly increases surface area to volume ratio of liquid water in our reactors. Feel free to drop us a line at info[at]skyfarmclimate.tech

I used to be on a research project that attempted to do this with a fungus/algae mix because when grown together the fungus suspended the algae throughout the column of water. That was a fun project that had it's funding pulled, and then I had to get into software engineering to make a living. What's the basic way of accomplishing your improvement?

I can share further details by email, but the gist is we enable much faster gas exchange for microalgae cells compared to existing systems, inside a unique reactor design that gives us some other benefits for common cultivation processes.

What do you dto with the algae after it has grown?

Sell it

Are you by chance growing spirulina algae? It's a popular supplement.

Not at the moment - but it is an option for the future. Technically it is a cyanobacteria not microalgae

Technically both…

Your website makes it sound like you're growing algae for co2 capture, but if you're selling it and not sequestering it then what's the point?

We're selling it as biochar, sorry should have specified.

Weird. So you are supposedly beating everyone in terms of yields and yet focus on producing something worth even less than protein per kg. Wouldn't it make more sense to cream off the market on higher value-added products before scaling up while expanding into increasingly low value products?

if you're trying to sequester carbon.. bury it. anything else will allow it to be released back into the atmosphere anyway

I once read a comment from an expert in that field who said that it was essentially impossible to prevent contamination, and that they had to constantly test and then shut down and sanitize when they discovered a different species of algae in their system.

How do you mitigate that issue? (And good news if you have a solution, that same person said they figured whoever solved that problem would be the world's first trillionaire).

Mitigation strategies are varied, you basically cannot guarantee there will not be any contamination if you are doing any kind of scale. We are looking at polycultures/consortiums (robust ecosystems inside one reactor), various filtration systems and high frequency monitoring. There are some others we won't publish (yet)

Out of curiosity, what are the challenges in scaling algae bioreactors?

They're easy to scale in some sense (just make a bunch of small ones), but small reactors have a high surface area to volume ratio -- i.e., a high expense to algae ratio. Making bigger vats is problematic because the work being done is proportional to surface area (light penetration) and because the chance of infection goes up exponentially.

Algae also produce waste that SMELLS. Now you have costs to deal with that, which also reduces _where_ you can put them, since most people don’t necessarily enjoy living near the smell of a wetland.

Then there are the ocean-based startups trying to just assist with what nature does out in nature. Also tough to scale when dealing with dropping structures in the ocean and making sure they work with as little maintenance as possible.

So both indoor “Ideal condition” and outdoor “Ideal condition” growing are actually really tough to scale cost effectively. Doing something _else_ with them while sequestering carbon could be interesting though. I know one team that is using algae to clean up wastewater wile producing electricity. I don’t think they’ll get to cost effective scale, but I think the idea tackles two great problems at once in a creative way, and that’s still progress!

Why don't we just scale them in the oceans?

That might disturb the ocean ecosystem.

And these trees don't?

I think the larger point is that there isn't a simple, obvious, "Why don't we just do XYZ?" solution to the problems being discussed here.

I agree anything we do at scale will affect the ecosystem. However, restoring an ecosystem to a previous state seems less risky than changing oceans to a new state.

Maintaining things sitting in the ocean is still expensive. You can’t send robots out, you must send humans.

Oil rigs are worthwhile just because they can be turned on/off relatively easily depending on market conditions and when they are on, they mint so much money that expensive humans are a rounding error.

Why can't you send robots out?

There are plans to add (I believe) iron oxide to the oceans to increase algae growth. Don't recall the organization's name right now.

I hope not. You can permanently alter (i.e. for decades) the climate in a region by creating an algae bloom.

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