REFERENCE
[Biofuels from Algae Cultivation]
(Am I taking the wrong approach?)
The idea of producing biofuel from algae comes up whenever the price of crude oil soars.
This is an argument that disappears when the price of crude oil falls, so it is not very good.
As someone who has been involved in mass cultivation both indoors and outdoors, I have doubts about the approach to biofuel production from algae.
First of all, is the current biofuel from algae cultivation profitable?
I know a researcher overseas who was researching the production of jet fuel from algae while receiving dazzling subsidies from the Air Force and a large aircraft manufacturer.
As a researcher, he was satisfied with the results once he had published a research paper, but he himself stated that biofuel was not profitable.
Naturally, algae-derived astaxanthin, which has currently captured a certain market share, is priced at around 1 million yen per kg in pure product terms. (As of August 2024)
Currently, astaxanthin is refined from an algae species called Haematococcus (containing 3-5% of the dried biomass), and the production process is as follows.
① Select an algae species containing astaxanthin and cultivate the specific species using one of the cultivation systems.
② After harvesting, centrifuge to separate the solid and liquid.
③ Dry the wet biomass after solid-liquid separation.
④ Extract and refine astaxanthin from the dried biomass using a solvent, etc.
Even if the astaxanthin obtained through all these processes is sold at around 1 million yen per kg (in pure product terms), it is extremely difficult to make a profit just by selling the material.
So what about producing biofuel from algae?
In reality, the process is basically the same as above.
And every step requires energy, manpower, and materials.
And can algae-derived biofuel really be sold for a few hundred yen per liter, when it requires the same amount of energy, manpower, and materials as the rare ingredient astaxanthin, which is traded for 1 million yen per kilogram, and also the construction of large-scale facilities?
Moreover, as we have mentioned before, algae cultivation itself is very unstable, and the cultivation technology itself is still in its infancy.
Unfortunately, the current discussion of algae-derived biofuel is the product of a huge multiplication of the champion data in a flask, ignoring how difficult it is to scale up.
We often hear the phrase, "We have succeeded in lowering the price of algae-derived biofuel to 100 yen!", but this is questionable as data to be made public.
No matter how generously we estimate, there are at least three zeros missing, or at worst four.
What this means is that we often hear announcements about how "genetic engineering technology..." or "seed breeding" have achieved a certain percentage increase in growth or biomass yield, but honestly, a percentage-order productivity increase is meaningless when there are three or four digits difference.
In my mind, there is only one scenario in which I can imagine that biofuel production from algae would be profitable.
That is, liquidating expensive rare components such as fucoxanthin, and producing biofuel from the algae biomass residue that is produced from that, in other words, the remaining waste.
In this case, generally speaking, it is industrial waste utilization, and biofuel can be produced with only the extraction and refining costs.
There are probably no other possibilities than this scheme.
I think that this approach of cultivating algae to produce biofuel is wrong.
However, utilizing the residues of algae cultivation is not so easy.
First of all, algae residues contain a lot of nutrients, so they can be used as supplements, livestock feed, and land-based fish feed.
The question is, is it really necessary to add an extraction process to such valuable residues to turn them into biofuel?
Another point is the problem of the methodology for cultivating algae efficiently, as we have mentioned before.
Since a large amount is absolutely necessary for biofuel, a method is proposed in which algae are cultivated in an outdoor open pond, where stable cultivation is extremely difficult, and on a huge scale.
However, if a method that is full of problems even on a small scale is enlarged as it is, it will only enlarge the problems and will not solve anything.
Some of the more eye-opening suggestions include the outrageous idea of increasing the water depth of the open pond from the current 10-30cm to 1m to increase the overall volume, or the idea of expanding pond cultivation as far as the eye can see in a desert area with few bacteria and no rain.
Anyone who has actually experienced outdoor cultivation in the field will probably understand why the above suggestions are outrageous.
The water depth of the open pond is only a few tens of centimeters even though the pond itself is large.
This is because if it is made deeper than that, the algae cells will cast shadows when the concentration reaches a certain level, and the light will not reach the inside.
As someone whose business has been centered on the development of cultivation equipment, even a water depth of 10cm is too deep.
Our equipment is indoor LED specification, but the design is such that the algae cells and the light source inside the cultivation equipment are not more than 2.5cm apart.
Therefore, sufficient light is evenly supplied to all algae cells, which increases the culture concentration (= yield).
At first glance, cultivation in the desert seems wonderful.
The land is almost free, and since it is an environment where plants do not grow well, there are certainly few germs.
And there is no rain and the sun always shines brightly.
However, if you think about it for a moment, you will realize that this plan is extremely reckless.
There are two main reasons for this. The first is what to do about water evaporation in the desert.
In the desert, where water is often said to be more valuable than wine, the water in a 30cm deep pond will evaporate in an instant.
Moreover, the sunlight in the desert is too strong for pond cultivation.
The other is the problem of sand in the desert.
If you develop an open pond in a desert area, a 30cm deep pond will quickly become filled with sand.
So, should we cover all of the vast open ponds with black plastic, like we do with outdoor vegetable cultivation in winter?
If we do that, sand will pile up on top of the cover and sunlight will not enter, and conversely, if sunlight passes through, the inside of the plastic will become extremely hot and the algae will die immediately.
Searching for a cultivation method for algae cultivation is always a continuous process of making compromises, and it is not a field in which you can get the best answer overnight.
If you try a certain method once and it doesn't work, you can use your experience to try the next method, and if that doesn't work, you can use your experience to find the next methodology.
My experience with algae cultivation is that you have to accumulate experience not at a desk or in a lab, but in actual large-scale cultivation.