WEEK #13

Pumps (not simultaneously) will extract the culture medium up to the filter/scraper module (see pictures). The medium will fall inside a shallow tub with a fine weave cloth (mesh density around 30 – 50 µm) at the bottom and a big funnel underneath that will recycle the filtered water directly into the pond of origin.

In order to select the destination pond, there is a servo-controlled flow divider valve at the end of the funnel so that the filtered water return back to where it came from.

The filtered water should be light green because it contains small “baby” spirulina too tinny to be stopped by the filter.

To facilitate the filtration, a scrapper positioned under the injector and activated by a lead screw will scrap the mesh continuously from side to side.

When the filtration process is done and the biomass left in the tub looks like a very thick paste, take out the biomass and store or press and dry it.

- Weighting the filtrate to get an estimation of the quantity of spirulina harvested. Filtered biomass contains 10 % dry matter (1 liter = 100 g dry spirulina) and 50 % residual culture medium.

- Sieving: Then the filtered culture passes through a sieve (mesh size about 200 µm) to remove any foreign matter such as insects, larvae, leaves and lumps of polysaccharide or muds from the bottom of the tank.

- Dewatering is accomplished by pressing the biomass enclosed in a piece of filtration cloth + a strong cotton cloth, either by hand or in any kind of press. The simplest is to apply pressure (0.15 kg/cm² is enough) by putting a heavy stone on the biomass bag.

The expelled "juice" comes out colorless. When it turns slightly green, we must stop (otherwise too much product will be lost). For the usual thickness of cake (about 2.5 cm after pressing), the pressing time is about 15 to 20 minutes.

Practically all the interstitial water (culture medium) is removed. The pH of the well pressed biomass is near 7 (neutrality).

- Cleaning: the pumps, the piping network and the filter/scrapper module should be purged with clean water after each harvest. Each pump is fitted with a purge valve that will let water flow into the network without leaking into the spirulina pounds. The flow divider at the end of the funnel has a 5^th valve solely dedicated to purge. The water will be released in an external water tank that can later be recycle for other needs.  

Filter/ Scrapper Module

WEEK #12

I think I finished the part about fertilizer for spirulina.

These are N(nitrate), P(phosphorus), K(potassium), S(sulfur), Mg(magnesium), Ca(calcium), Fe(iron).
All the quantity needed is contained in urine except iron.

I thought about making a closed loop from the toilet to the spirulina ponds.

Iron can be produced at home using rusted nail, vinegar and lemon.

Also I explained how to make a micro-nutrient solution.

Maybe I should add a part concerning another way of supplying those basic fertilizers.



Here is a quick sketch to understand the process.

WEEK #11

I think I'm done with the Carbon part of the nutrient for the culture.

https://docs.google.com/document/d/1FFv9O0h2KTwieUe7OaM7hpXMV1D4opDH_TNcfhy4eSU/edit?usp=sharing

- Writing about my thoughts

- I did a mistake in the previous calculation. Here is the correction. Citric Acid + Baking Soda is still not worth considering.

- Sugar with Yeast calculation.
Theoretical equation for Aerobic fermentation : we need 77.3 g of sugar to produce 112 g of CO2. Which is equivalent to a ratio of around 150%. It's very interesting.
However the yeast can't consume that amount of glucose in one day. And also one of the most important thing is that the enzymes of the yeast cannot keep this high yield. We can expect 50% less than the theoretical production maybe.

- This chemical reaction still needs a lot of external resources to produce CO2. But given that theory, we could use compost to generate CO2 and deliver it to the Spirulina Green House.
However after further research I discovered that we get the highest CO2 production with "Anaerobic composting", the second highest production is "Vermicomposting"and finally the less productive is "Aerobic composting".
This difference between the yeast fermentation and the composting is probably due to the complexity of the reactions within the composting bin.

WEEK #10

I've got further into the CO2 feeding issue.

There several ways which would be interesting for my scale. Some are from existing technologies, some are my ideas:

• Citric Acid + Baking Soda = CO2

This solution produce CO2 out of the chemical reaction between Citric Acid and Sodium Bicarbonate. As I calculated before,  I need about 112 g of CO2 a day to boost the growth efficiently.

Thus I had to calculate the yield of this first solution. How much Baking Soda and Acid do I need in order to get 112 g of CO2.

The chemical equation: 1 C6H8O7 + 3 NaHCO3 → 1 Na3C6H5O7 + 3 H2O + 3 CO2 

I found that I need 164 g of Citric Acid and 216 g of Sodium Bicarbonate every day ! 

This is a lot and require purchasing those elements from a factory. And for the acid it's equivalent to 1233 lemons a day !! This not efficient !

Conclusion : NO

• Sodium Bicarbonate feeding

We need 2 to 6 kg by kg of spirulina. Therefore, when we harvest 140 g of spirulina we need to inject around 560 g everyday. This doesn't look very sustainable... Unless we live in area with a lot of trona ores that we could easily extract transform into baking soda.

Conclusion : NO (but it's the most used technique)

• Fermentation Sugar + Yeast = CO2

There 2 reactions possible:

- Aerobic fermentation: C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy

- Anaerobic fermentation: C6H12O6 → 2 CH3CH2OH + 2 CO2 + energy

As you can see the aerobic fermentation produce 4 time more CO2.

Later I will try to get some accurate calculation. But this process is way less stable than the acid and baking soda reaction. Also the reaction depend on the catalyzing rate by the enzymes of the yeast.

However, this would be a non-negligible source of CO2. Plus, the idea would be to send the CO2 emission from a food/human/animal waste composting reactor back into the spirulina greenhouse or directly into the ponds by an injector/diffuser. I need to develop this idea to see how I can integrate it in a living system.

Conclusion : not a lot but still interesting and good to combine with something else

• Human exhalation live capture

Humans exhale around 1 kg of CO2 everyday. This is 9 times what we need for our culture !

However this is very difficult to collect because the air we breathe out is composed by (still) 14% O2, 78% N2, 4% CO2.

But, in a closed room where 1 or more human is sleeping the concentration in CO2 increase. For example, outside it's supposed to be 400ppm of CO2 and inside in a room windows closed, it easily reaches 1500 ppm and more. In a classroom or office it can reach 3000ppm. 

One solution would be to send the air of a bedroom (or a room with humans or animals) directly to the greenhouse. Again some calculations are needed to get rates and yields. 

Conclusion : not a lot but still interesting and good to combine with something else

• Volcanic gases capture

Volcanic gases are very rich in CO2. If this living system is installed in a volcanic zone I guess it would be possible to capture gases directly from the soil.

Here we can see the composition of different fumarolic gases : https://www.sciencedirect.com/science/article/pii/S0377027396000960

The sulfur emission could be a problem for spirulina. Maybe we can find easy ways to neutralize it.

Conclusion: Need calculation

• Soda lakes input

Soda lake are already rich in CO2 it could be an interesting input to drain and change the water. If this living system is implemented near by a soda lake, it would be very useful.

Conclusion: Need calculation and further research

• Urine feeding

Urine contains almost all of what spirulina needs including carbon. Feeding the culture exclusively with urine increase the spirulina growth to around 2 g/m2/day. (need some more clarification and calculation).

Conclusion : Good




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True autonomy (and freedom) is to go back in time and be hunter-collectors again.

I think it's only important to reduce our consumption to the size of earth.
Therefore, there will always be dependencies to certain mines and factory but we need to minimize it, in order to make their impact on the environment very very tiny. 

I conclude that a society system is needed to continue.

WEEK #9

I had a lot of questions last week after learning about energy productions.

We can see that for example thorium fusion reactor would be way more efficient and portable than usual fusion reactors are. However this project is on the table since the 60' in many different countries but nothing moves.
Also similar with big molten salt batteries. It's here since a long time but nothing really works. And this is true for many other technologies.
The question of the energy production and storage is primary to evaluate the human evolution. But unfortunately it seems that we are stuck at this stage of our evolution.

Actually this connect with the article you shared me about how scientific discoveries are decreasing and that the time between new major discoveries is increasing.


I've also been continuing writing my doc about spirulina.
Now, I'm trying the gather and sort the techniques that allow us to directly feed spirulina by CO2 injections.

One is yeast fermentation with sugar, the second is bicarbonate and acid citric chemical reaction and the last one is an idea of collecting human expired CO2 with breath mask connected to a gas tank. But this last idea doesn't seem to be interested as we expire not only CO2 but everything we breath in with different concentration. We could use this device when we do indoor activities, sleeping, etc.

Practicing drawing a little. Hope to do more in the future if I find a good subject.

WEEK #8

1 Food:

• spirulina
• lemon (can be grown in the hydroponic greenhouse)
• other vegetable depending on the season and area (can be grown in the hydroponic greenhouse)
• goat (milk and cheese)
• chicken
• fishes from fishing

2 Home:

• Module 1 - House
• Module 2 - Workshop
• Module 3 - Greenhouse (hydroponic system + fish pond to make the water rich in nutrient)
• Module 4 - Spirulina (connected to green house)

A dome made of soil to insulate even better 

Insulation panels made of mycelium

3 Energy:

• Solar panels on the dome

• Solution : 2000 WATT system
• https://www.mobile-solarpower.com/2000-watt-24v-solar-system.html

4 Health:

• medicinal plant cultivated in the green house and outside.
• list of antibiotic recipe + basic chemicals stock

5 Knowledge:

• The internet
• Book Bank
• Music Bank
• Movie bank
• CAD Bank

6 Tools:

• A workshop (fablab)
• Tools for the maximum
• 3D printers
• Laser Cutter
• Sewing machines
• Welding
• Material stock

Manufacturing should be standardized 

7 Mobility:

• ??? I still have the idea to make an electric motorbike in carbon one day.
• Bicycle
• Truck???
• Sailing boat
• Ultra Light Aircraft

8 Social Connections:

• Internet
• Proximity with people ???

research :
- LFTR (Liquid Fluoride Thorium Reactor) (no)
- Liquid Metal Battery (no)
- http://www.mdpub.com/SolarPanel/
- biomass gasifier :http://www.mdpub.com/gasifier/index.html
- Wind Turbine http://www.mdpub.com/Wind_Turbine/index.html

WEEK #7

Still writing, I also took a lot of time on independent study.
I'll draw soon.