Fifteen years ago we were talking about how algae biodiesel was going to prevent global warming. A few people would admit that the challenge was going from algae growing in the pipes to algae growing on the pipes, where it could not be harvested. Fifteen years later few people talk about these designs, which means nobody solved the problems before the money ran out.
As I was reading this article, I started thinking, "what we really need is a surface area you can extract and expand", and the image of a roll of corrugated material came into my head. It's a lot of surface area in a cylindrical space, and when unwound you have substantial access to the surface. No nooks and crannies that you can't reach with a simple tool.
The other route to go is what the pool industry does, which is to 'shock' the system, which essentially means to poison the microbes in such a way that they fall into suspension and you can filter them out (possibly with a separate filter so you don't foul the standard one). But that shuts the whole system down for some time. Not a showstopper if you can rotate out reactors, but I think you'd be better off with a replaceable parts mentality, swapping out parts for maintenance and cleaning and bringing the system online faster.
[ES: Educational and professional experience. All this comes with caveats because many parts of working with algae are unsolved, you probably won't get all of these properties at once.]
Algae are much more efficient for various reasons. Or rather, the efficiency ceiling is higher, whether it is realized is a separate question.
They make better use of space (your culture may vary).
They can have a higher proportion of their mass as oil or protein (relevant if you're harvesting them for food).
They are highly adaptable, they can acclimate themselves to new environments readily.
They are simpler and lack the "overhead" of vascular plants.
Relatedly, on paper at least it's a very nice system to engineer. You've got a logistic growth curve (a sigmoid) for biomass in suspension, and you're harvesting when you get to the flat part of the curve to "rewind" to the exponential part of the curve, so you're staying in the part which is very productive. Biomass is difficult to measure, but there are good proxies for it (such as pH, optical density, or conductivity).
You can get many harvests in a year, you may be able to harvest them every day or every week depending on conditions (I've worked in an algae farm that harvested every day during the summer and occasionally in the off season [though technically it was cyanobacteria, which some don't count as algae, it's kind of a Pluto situation]). Vascular plants I think are usually harvested 1 to 3 times a year (though I won't discount someone clever being able to get more harvests by harvesting sap or something like that).
One of the important bits about use of space is that you can do it so you're not taking land use away from food growth, because you can grow algae in places you can't grow crops.
I don't see that as a very strong reason, you can cultivate algae for food (spirulina, chlorella) and you can use adjacent technologies (controlled environment agriculture) to grow vascular plants in harsh environments.
> A few people would admit that the challenge was going from algae growing in the pipes to algae growing on the pipes, where it could not be harvested.
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."
Algae isn't hard to grow and makes great fuel, it's just very difficult to harvest (and depending on what you're doing, biofouling may make it difficult to maintain a system long term). Things like corn and soybeans work okay to create fuel, but they're easy to harvest. (Note that we aren't using wild types of vascular plants either, except in eg wood stoves.)
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.
I suppose it makes sense to pivot, if you can find someone who’ll pay you $100 for a gallon of dried algae, versus $4 for a gallon of algae lipids catalyzed into fuel. And how many gallons of algae does that take?
The dream would be to efficiently fractionate your algae, and separate out lipids, proteins, carbohydrates, and specific high value stuff like phycocyanin or astaxanthin. Then you could sell into these high margin markets to supplement your fuel production.
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.
I bet even as an animal feed supplement it makes more sense than making fuel. We have connected the dots between feed and healthiness of fish and eggs. For ungulates I understand you have to beware of high protein. Unrestricted access to clover (which is one of the most palatable things they can eat) can make them quite sick. An algae/clover blend could probably still be palatable, and if you selected for high fat to protein ratio in the algae it might actually be safer.
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.
Why grow fuel, and not a fertilizer/top-soil additive for agriculture or soil remediation? If you've got a product which contains that much carbon, covering fields with it is a great way to take CO2 from the air and put it in the ground while also improving the soil.
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.
No idea how reliable or good that revenue source is now, or in the long term.
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 very recently tried and failed to commercialise a novel bioreactor system for microalgae [0]. You are correct that surface area is an important factor in considering algal growth characteristics.
In my opinion, microalgae production for bulk purposes (i.e. biofuels rather than current pharma usages) has thus far failed because the existing cultivation systems are very energy intensive (pumps), labour intensive (cleaning), and inconsistent (cell growth and lipid concentrations are more or less non-deterministic). This all means that the cost of production is higher than what you can sell the raw output for in most cases.
Our novel approach was to engineer growth media aerosols (100 micron diameter microdroplets), and suspend microalage cells inside each microdroplet. Then we made a literal cloud (microdroplet air suspension) inside an environmentally controlled greenhouse volume. Doing this enables an extremely large surface area contact between the growth media and atmosphere (also CO2 enriched atmosphere), as well as energy efficient mixing and circulation processes. Our calculations showed that orders of magnitude energy efficiency improvements are possible compared to existing cultivation systems (raceways, tubular PBRs), and additionally scaling is inherently possible due to the ease of building out larger and larger volumes to contain such microdroplet atmospheric suspensions.
Existing systems cannot be effectively scaled due to e.g. pressure limitations associated with tall water volumes, risks of culture contamination, light penetration etc.
Thanks for sharing your experience. Can you talk about the business aspect? Like I assume up to now you're having trouble getting additional funding? What worked and didn't work? What's the current direction?
Currently we have ceased all work due to lack of funds - there are multiple reasons behind this, but we are still bullish on the tech. Our university partners may develop it further, or I may come back to it in a few years when my situation changes.
A core takeaway from our investors is that we should have tried harder to demonstrate strong market pull for our reactors, or the microalgae itself. In this respect it was a kind of chicken and egg problem, in that microalgae can be used for many different things, but no one is doing it because it is too expensive, and the existing markets are supply saturated.
The reason is that if you mow the prairie, you will get droughts and floods. The grass captures water and reduces evaportation, and makes it a soil rather than dirt. Plus you are still left with the problem of replanting it.
Harvesting the algae is one of the problems, but the more pertinent problem that breaks the economics is that the energy density at the generation point just isn't good enough. Going from sunlight to biodiesel via algae seems to have single-digit efficiency.
Almost his first words were: “Well, Dr. Weizmann, we need thirty thousand tons of acetone. Can you make it?” I was so terrified by this lordly request that I almost turned tail. I answered: “So far I have succeeded in making a few hundred cubic centimeters of acetone at a time by the fermentation process. I do my work in a laboratory. I am not a technician, I am only a research chemist. But, if I were somehow able to produce a ton of acetone, I would be able to multiply that by any factor you chose.” . . . I was given carte blanche by Mr. Churchill and the department, and I took upon myself a task which was to tax all my energies for the next two years.
(The Making of the Atom Bomb: Richard Rhodes)
- Chaim Weizmann, then Manchester University, subsequently the president of Israel, on his method of using B-Y Bacteria to "brew" acetone. This very probably single-handedly ended a materiels supply crisis for shell explosives, affected the conduct of WW1 and led directly in turn to the post-war politics of Palestine and the nascent state of Israel.
>...gin factory in Bow, London, so industrial scale production of acetone could begin in six British distilleries requisitioned for the purpose in early 1916. The effort produced 30,000 tonnes of acetone during the war...
Evidently, he delivered exactly the amount Churchill requested. That is an incredible feat to go from bench to industrial scale within a couple of years. Was there any other putative process on the table at the time or was the entire acetone effort dependent upon scaling up Weizmann's process?
Hate to use wikipedia as the source, but it states:
The production of butanol by biological means was first performed by Louis Pasteur in 1861.[5] In 1905, Austrian biochemist Franz Schardinger found that acetone could similarly be produced.[5] In 1910 Auguste Fernbach (1860–1939) developed a bacterial fermentation process using potato starch as a feedstock in the production of butanol.[6]
Methanol, Ethanol and Acetic acid (vinegar) production probably were the only precursor methods of bio reactor well understood.
Penicillin which was significant in WW22 was industrialised at scale by Du Pont and the USDA in Peoria using bioreactors. the British method (Ernest Chain Howard Florey), demanded huge surface area mould growing, in semi-open trays based on bedpans, which is what they jury-rigged in the lab for the first production cycles. du Pont took it and ran with it.
Leonard Bickel's biography of Florey has quite a lot about the industrialisation of production in bioreactors.
If you want another good story about them, read up on Quorn, and why it was invented and how Fusarium was bred up in bioreactors to try and make protein at scale. It was Lord Rank (the naked man banging the gong at the front of movies... No thats not Lord Rank, (it was his movie company) but it should be) who pushed for this, concerned about Soylent-green futures
Horizontal scaling makes sense and especially for startups. I remember discussing this approach with investor type people interested in biotech and the response kept falling back on maximum litres and comparison to existing hugeness of reactors. Which I thought was missing the point entirely! Some bioproducts can be sold for $1 million a gram. It doesn't take a genius to realise that size isn't everything in bioreactors.
Things that cost $1M/gram tend to have very low yield, a bit like how in gold mining you need to process huge volumes of rock to find the sparse gold nuggets.
continuous bioreactors are a pain to operate due to high risk of contamination, need for precise environment control and validation protocols. They have also been known for decades and are extensively used in process development. Despite all that most things are still produced in (fed)batch mode. So yeah thats still mostly marketing talk from ginkgo people, that are well-known for this kinda shit
32 comments
[ 3.3 ms ] story [ 77.7 ms ] threadAs I was reading this article, I started thinking, "what we really need is a surface area you can extract and expand", and the image of a roll of corrugated material came into my head. It's a lot of surface area in a cylindrical space, and when unwound you have substantial access to the surface. No nooks and crannies that you can't reach with a simple tool.
The other route to go is what the pool industry does, which is to 'shock' the system, which essentially means to poison the microbes in such a way that they fall into suspension and you can filter them out (possibly with a separate filter so you don't foul the standard one). But that shuts the whole system down for some time. Not a showstopper if you can rotate out reactors, but I think you'd be better off with a replaceable parts mentality, swapping out parts for maintenance and cleaning and bringing the system online faster.
This is more land efficient than growing plants.
Some people used carbon capture to carbonate the water.
Algae are much more efficient for various reasons. Or rather, the efficiency ceiling is higher, whether it is realized is a separate question.
They make better use of space (your culture may vary).
They can have a higher proportion of their mass as oil or protein (relevant if you're harvesting them for food).
They are highly adaptable, they can acclimate themselves to new environments readily.
They are simpler and lack the "overhead" of vascular plants.
Relatedly, on paper at least it's a very nice system to engineer. You've got a logistic growth curve (a sigmoid) for biomass in suspension, and you're harvesting when you get to the flat part of the curve to "rewind" to the exponential part of the curve, so you're staying in the part which is very productive. Biomass is difficult to measure, but there are good proxies for it (such as pH, optical density, or conductivity).
You can get many harvests in a year, you may be able to harvest them every day or every week depending on conditions (I've worked in an algae farm that harvested every day during the summer and occasionally in the off season [though technically it was cyanobacteria, which some don't count as algae, it's kind of a Pluto situation]). Vascular plants I think are usually harvested 1 to 3 times a year (though I won't discount someone clever being able to get more harvests by harvesting sap or something like that).
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-...
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.
In my opinion, microalgae production for bulk purposes (i.e. biofuels rather than current pharma usages) has thus far failed because the existing cultivation systems are very energy intensive (pumps), labour intensive (cleaning), and inconsistent (cell growth and lipid concentrations are more or less non-deterministic). This all means that the cost of production is higher than what you can sell the raw output for in most cases.
Our novel approach was to engineer growth media aerosols (100 micron diameter microdroplets), and suspend microalage cells inside each microdroplet. Then we made a literal cloud (microdroplet air suspension) inside an environmentally controlled greenhouse volume. Doing this enables an extremely large surface area contact between the growth media and atmosphere (also CO2 enriched atmosphere), as well as energy efficient mixing and circulation processes. Our calculations showed that orders of magnitude energy efficiency improvements are possible compared to existing cultivation systems (raceways, tubular PBRs), and additionally scaling is inherently possible due to the ease of building out larger and larger volumes to contain such microdroplet atmospheric suspensions.
Existing systems cannot be effectively scaled due to e.g. pressure limitations associated with tall water volumes, risks of culture contamination, light penetration etc.
[0] https://skyfarmclimate.tech/
A core takeaway from our investors is that we should have tried harder to demonstrate strong market pull for our reactors, or the microalgae itself. In this respect it was a kind of chicken and egg problem, in that microalgae can be used for many different things, but no one is doing it because it is too expensive, and the existing markets are supply saturated.
I was also very bullish on cellulosic biofuels from switchgrass. Just mow the prairies (don't disturb the soil).
I'd love to know why I was wrong. Too soon? Like GM's EV1? Little potential for Wright's Law (learning curve) to drive down costs?
> corrugated material
Very interesting. I hope someone tries this.
That said, all the (huge scale) biofuel options will likely be mooted by green hydrogen. Fingers crossed.
(The Making of the Atom Bomb: Richard Rhodes)
- Chaim Weizmann, then Manchester University, subsequently the president of Israel, on his method of using B-Y Bacteria to "brew" acetone. This very probably single-handedly ended a materiels supply crisis for shell explosives, affected the conduct of WW1 and led directly in turn to the post-war politics of Palestine and the nascent state of Israel.
>...gin factory in Bow, London, so industrial scale production of acetone could begin in six British distilleries requisitioned for the purpose in early 1916. The effort produced 30,000 tonnes of acetone during the war...
Evidently, he delivered exactly the amount Churchill requested. That is an incredible feat to go from bench to industrial scale within a couple of years. Was there any other putative process on the table at the time or was the entire acetone effort dependent upon scaling up Weizmann's process?
[0] https://en.wikipedia.org/wiki/Chaim_Weizmann
The production of butanol by biological means was first performed by Louis Pasteur in 1861.[5] In 1905, Austrian biochemist Franz Schardinger found that acetone could similarly be produced.[5] In 1910 Auguste Fernbach (1860–1939) developed a bacterial fermentation process using potato starch as a feedstock in the production of butanol.[6]
https://en.wikipedia.org/wiki/Acetone%E2%80%93butanol%E2%80%...
Methanol, Ethanol and Acetic acid (vinegar) production probably were the only precursor methods of bio reactor well understood.
Penicillin which was significant in WW22 was industrialised at scale by Du Pont and the USDA in Peoria using bioreactors. the British method (Ernest Chain Howard Florey), demanded huge surface area mould growing, in semi-open trays based on bedpans, which is what they jury-rigged in the lab for the first production cycles. du Pont took it and ran with it.
Leonard Bickel's biography of Florey has quite a lot about the industrialisation of production in bioreactors.
If you want another good story about them, read up on Quorn, and why it was invented and how Fusarium was bred up in bioreactors to try and make protein at scale. It was Lord Rank (the naked man banging the gong at the front of movies... No thats not Lord Rank, (it was his movie company) but it should be) who pushed for this, concerned about Soylent-green futures
https://en.wikipedia.org/wiki/Quorn
> The bioreactor was designed for the chemistry industry.
Bioreactors are talked about a lot in homesteading. If you want to re-image it that would be a nice start.
Every house not on town sewerage has a bioreactor and dams are natural bioreactors, there are products to mange these, but they are not tested - https://www.amazon.com/Splosht-Large-Fishpond-Water-Feature/...
It'd be interesting to see a bioreactor for more general waste, like wood and plant matter.
> antimalarial drug precursors
I'm dubious if big pharma has a problem with this it hasn't solved it.
Is that what a compost bin is?