An Algae Bioreactor From Recycled Water Bottles

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Introduction: An Algae Bioreactor From Recycled Water Bottles

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In this instructable, we describe how to build a photo-bioreactor that uses algae to convert carbon dioxide and sunlight into energy. The energy that is produced is in the form of algae biomass. The photo-bioreactor is built from plastic recycled water bottles. By designing the apparatus to be compartmentalized, we are able to do many experiments in parallel.

Michael Fischer
mfischer @t stanford.edu



By using algae as a biofuel, we can increase the world's supply of oil while at the same time we decrease the amount of atmospheric carbon dioxide used during its production. The resulting product is a sustainable biofuel whose carbon footprint is neutral inasmuch as the CO2 produced on consumption is essentially balanced by the CO2 used in its production. In this instructable, we first make the carbon dioxide delivery system, then mount the water bottles on a rack, and then inoculate the bottles with algae. After letting the algae grow for a week, we extract the biomass.

Step 1: Make Carbon Dioxide Delivery System

To make the carbon dioxide delivery system, connect an eight port sprinkler system manifold to a one inch long PVC pipe. To get good seals, use Teflon tape to tape the threads before attaching the pieces together. Next, attach the one inch pipe to a T-connector. Block off one end of the T-connector and attach the other end to a foot long PVC pipe.

Step 2: Attach Tubing to Manifold

For each manifold, cut eight-pieces of flexible tubing and connect each piece to a port of the manifold. The manifold that I am using has a dial on each port to control the rate of flow. Make sure all the ports that you use are open and allow approximately the same amount of carbon dioxide to flow through the port.

Step 3: Mount Carbon Dioxide System

Mount the air system to a metal rack using zip ties. Attach the air system to a tank of carbon dioxide.

Step 4: Mount Water Bottles

Hot glue the water bottles to the metal rack.

Step 5: Make Algae Media

We next make the medium to grow the algae. Although there are many possible mediums, a standard garden store fertilizer contains all the nitrogen and nutrients that the algae need.

Step 6: Media Inoculation

A good source of algae is pond algae, if available. If not, there are a large number of online vendors that sell batches of algae. To inoculate the culture, measure out a fixed amount of algae and add it to the growth medium.

Step 7: Growth and Harvesting

After several days of sunlight and CO2 exposure, the algae are much denser. A French press is then used to extract the algae from the solution. The biomass of the dried algae can then be used as a fuel. As a by-product of this process, a large amount of atmospheric CO2 is sequestered.

By: Michael Fischer, Stanford University, mfischer @t stanford.edu

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In terms of carbon dioxide being released what if we

1. Burned it with a high concentration to replace coal or partly.

2. Reduce rotting of algae that releases methane into the air.

3. Made algae to absorb CO2 from the air.

if you shown us how to make it how do we link this to make power?

I cant understand how algae can used for this kind of stuff, is the algae making such as biogas or we must took the algae out and produce it to be a niofuel ??

After reading as many of these comments as I could stand it's obvious to me that we will all have to evolve to breathe CO2 and H2O.

Or drown and suffocate....together.

So what do I do with the algae to so that it doesn't get burned or decay letting CO2back In to the air

To keep the C from cycling back into the atmosphere sounds like it might be difficult.

If you use the algae as a feed then the C is used to prododuce new animal biomass (whether it's a fish or a human, ect.) although once that organism dies then bacteria will get to work and the C will once again be in the atmosphere.

There is a man who spoke about sequestering all the excess CO2 in our atmosphere in the soil by increasing root production, combined with no till. the idea is that if plants take CO2 from the atmosphere and use it to produce deeper roots and we do not till it, then most of the C will continue to stay below ground and the level of soil will increase. ... So perhaps burying the algae could cause it to become sequestered. Probably not a reasonable thing to do, but it will be just like what happened millions of years ago that provides is with fossil fuel oil today.

A tree could sequester biomass if you turned it into furniture or a house. Burning it is carbon neutral, as long as you're farming trees. Burning the algae would be carbon neutral. Turning it into plastic or something might sequester the captured carbon - if you were careful about the energy you used in the process.

Burning anything is not carbon NEUTRAL....Burning releases the carbon into our atmosphere...back to chem. class.......

tsk tsk - perhaps you should re-read what I've said?