4 ms·
How is the CO2 sequestered? That is conspicuously missing from that marketing blog post.
by rcme 4y ago
How is the CO2 sequestered? That is conspicuously missing from that marketing blog post.
- chasil 4y agoIn nature, the dying algae fall to the sea floor, and sequester the carbon there. An easy stimulant to this process is to dump powdered iron into an algal bloom. https://en.m.wikipedia.org/wiki/Iron_fertilization https://en.m.wikipedia.org/wiki/Iron_fertilization
- mikepurvis 4y agoI'd be interested to know more about the carbon cost of production for the powdered iron. I assume you could use scrap metal for this purpose, but scrap metal is already pretty recyclable as I understand it.
- whatshisface 4y agoI don't think pure iron would work because it's not soluble - what people use are iron sulfates which are minerals that occur naturally.
- chmod775 4y agoFerrous sulphate is available below $100 / ton and seems to already be used in large quantities for wastewater treatment. Doesn't seem hard to source if the same stuff will work for algae.
- mikepurvis 4y agoOkay neat— the WP page for it mentions it being produced at least in part as a byproduct of steel production: "In the finishing of steel prior to plating or coating, the steel sheet or rod is passed through pickling baths of sulfuric acid. This treatment produces large quantities of iron(II) sulfate as a by-product." https://en.wikipedia.org/wiki/Iron%28II%29_sulfate#Production_and_reactions https://en.wikipedia.org/wiki/Iron%28II%29_sulfate#Productio... So I guess that explains why it's so inexpensive, but of course as with many such things (natural gas from oil production, whey from yogurt/cheese production, etc), once there's a robust market for the "byproduct", it can result in changing the original economics.
- ttyprintk 4y agoHowever, you run the risk of advantaging algae that produce high levels of toxin. Even non-toxic algae starts to do this when concentrated. Since iron fertilization only works far offshore, a lot of our industry has to hope that bloom doesn’t enter the food chain.