Food supplements are a much higher ticket item than fuel. It's a lot easier to make money that way. But you're right, pivoting to some kind of food product is a cliche.
Or you could not do any of that and press your dry algae into a pill and sell it at a high margin. As far as the profit motive goes, it just doesn't add up. So the dream dies on the vine.
I'd love to see the government pour money into this and build a plant that operated this way at a loss, on a sort of Apollo project basis; it wouldn't necessarily make financial sense, but we'd generate a bunch of great technology which would be applicable in many areas, and eventually it just might work. I think it's worth a shot to see if we can sustainably meet our food and fuel needs, maybe even in a carbon negative manner. But sadly I think we're going in a different direction.
As someone once put it, “oil is so plentiful we can afford to set it on fire”. Finding something else we can set on fire will be difficult, but it might be better to pyrolyze it directly and feed electricity into the power grid. The waste heat from the heat engine could be used in a heat exchanger to dry the algae before firing.
Speaking of power, the cooling effect of photosynthesis is also an underexplored areas.
Cover millions of acres of marginal/desert soil with sheets of algal mesh built for moisture retention. Plant trees or crops into it.
That it can't be burnt and turned back into CO2 seems like a positive, not a negative.
Oh, it doesn't make money? I guess that's the rub.
I wonder how hard it would be to make such an "algal mat". I would use something like this around here on my little farm/vineyard even as a kind of weed block, alternative to "plastic mulch": rolls of algal-produced fibrous mats, 2" or so thick. Permeable so water and air can get through, but thick and tight enough that weeds get blocked out. Would just degrade or be tilled into soil over time.
There's already equipment out there for laying "plastic mulch" but the stuff itself is fairly controversial because even the biodegradable stuff is still a plastic. If one could economically produce such a thing made out of algae, and compete with plastics on cost, that would be pretty damned nifty.
That and just some kind of bulk powder that can be soil incorporated as a carbon amendment. Pay farmers to lay the stuff down in huge quantities as a way of improving soil while getting CO2 out of the atmosphere.
Even better if a bioreactor and related equipment to make this stuff could be made to operate locally on site.
I'm not an expert here but I've done a lot of reading on this.
My understanding is that people really don't have a hard time growing algae, it's just that algae doesn't make very good fuel.
This is evidenced, IMHO, by the vast number of companies that started as algae fuel producers and then pivot to algae supplement companies.
This article goes more in depth on the topic [0].
"One of the biggest challenges was that wild strains of algae couldn’t deliver the high levels of lipids needed to produce large quantities of fuel, said Todd Peterson, the former CTO of Viridos, Exxon’s longstanding and now former algae research partner."
[0] https://www.theguardian.com/environment/2023/mar/17/big-oil-...