I created this instructable to show how to build a simple algae based CO2 scrubber for home or apartment use. The basic design shown here will scrub its own consumption and approximately 24 pounds of carbon dioxide from the atmosphere every year. This is approximately the CO2 produced in the production of 17kW of electricity. This device may be scaled up to process larger quantities of CO2.
The carbon dioxide is consumed by the algae which release oxygen. In part I the scrubber consists of a 2 liter reactor vessel and a small aquarium air pump. The bottle contains a solution of water, algae and nutrients. Room air is passed through the bottles using a standard aquarium bubbler stone where the CO2 is absorbed by the algae and oxygen released.
In later parts this basic design will be expanded provide more flexibility and increased production.
Maintenance is simple and straightforward as any house plant. About twice a month I add a couple drops of liquid plant food. The color of your home scrubber may be kept at any desired color range by controlling the food. If the algae gets too dark for your taste simply wait until the color begins to lighten before feeding again, if its too light try adding another drop of nutrient or feeding more often to increase the population.
Once or twice a year its probably not a bad idea to clean the scrubber. Save enough medium from one of the lightest bottles to reseed them. Then empty them into your compost heap, the sink or the toilet and restart them using tap water and the reserved medium.
All that being said, let's take a quick look at the tools and materials we'll be using then we'll get started.
The carbon dioxide is consumed by the algae which release oxygen. In part I the scrubber consists of a 2 liter reactor vessel and a small aquarium air pump. The bottle contains a solution of water, algae and nutrients. Room air is passed through the bottles using a standard aquarium bubbler stone where the CO2 is absorbed by the algae and oxygen released.
In later parts this basic design will be expanded provide more flexibility and increased production.
Maintenance is simple and straightforward as any house plant. About twice a month I add a couple drops of liquid plant food. The color of your home scrubber may be kept at any desired color range by controlling the food. If the algae gets too dark for your taste simply wait until the color begins to lighten before feeding again, if its too light try adding another drop of nutrient or feeding more often to increase the population.
Once or twice a year its probably not a bad idea to clean the scrubber. Save enough medium from one of the lightest bottles to reseed them. Then empty them into your compost heap, the sink or the toilet and restart them using tap water and the reserved medium.
All that being said, let's take a quick look at the tools and materials we'll be using then we'll get started.
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Signing UpStep 1: Bill of Materials
Okay here's what we'll need:
Tools:
Drill or drill press with 3/16" bit
Razor knife or scissors
Hot glue gun - Optional
Funnel - Optional for filling bottles
Materials and where I got them. I have no relationship with any of these stores or products. They are inexpensive and should be commonly available:
1 X 8' 1/4" aquarium airline tubing - PetSmart Top Fin brand or ACE Hardware flexible plastic tubing
1 X 3' 1/8" inch rigid plastic air hose (3/16 outer diameter) - PetSmart Top Fin brand
1 package 6 air stones - PetSmart Top Fin brand (also available individually)
1 x 2L Clear Plastic soft drink or water bottle with screw on top - Recycled
1 x 2L de-chlorinated water for breeder reactor
On the next page we'll learn more about dechlorination
Tools:
Drill or drill press with 3/16" bit
Razor knife or scissors
Hot glue gun - Optional
Funnel - Optional for filling bottles
Materials and where I got them. I have no relationship with any of these stores or products. They are inexpensive and should be commonly available:
1 X 8' 1/4" aquarium airline tubing - PetSmart Top Fin brand or ACE Hardware flexible plastic tubing
1 X 3' 1/8" inch rigid plastic air hose (3/16 outer diameter) - PetSmart Top Fin brand
1 package 6 air stones - PetSmart Top Fin brand (also available individually)
1 x 2L Clear Plastic soft drink or water bottle with screw on top - Recycled
1 x 2L de-chlorinated water for breeder reactor
On the next page we'll learn more about dechlorination
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If you are using liquid plant food remember a little goes a long way.
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Ok, the forum ate my first version of this post even after me seeing previews and seeing it posted after I hit the "Post Comment" button. I suspect my session timed out and the system is not smart enough to deal with me coming back in terms of an error or recovery. Fine, it happens - not all software can be great software. So I retype a second time and try switching to the "Rich Editor" (which is apparently quite poor) and everything I had typed in the plain editor was deleted and replaced with a really fancy display advertisement inside the editor window! ??? It's 2012, not 2002 folks...this is just poor. My first and last day of posting here all at once.... :(
Good luck to all. Seems like the contributors here are doing really interesting things and are very enthusiastic. Sorry to abbreviate so much on my third try (at least I explained above?), there was some commentary that I'm not rewriting again...here's the links though, maybe they'll be interesting or useful to someone:
http://solar-components.com/AQUA.HTM
http://www.aqua-medic.com/products/plankton-reactors-saltwater/
A few thoughts/links to add which may be helpful or interesting.
A German company (US branch) called Aqua-Medic makes a line of so-called plankton reactors which might be useful if anyone wants to get a little more sophisticated. They come with some fittings and a valve at the bottom (or looks like just a valve on the littlest one) that allow a way to inject air strategically and to make draining convenient.
If you're inclined to "go big" (and vertical) you might consider these algae-culture cylinders from Solar Components Corp. While not the cheapest net price/gallon, that's the best deal per square foot of floor space that I'm aware of.
There used to be a drip irrigation kit for sale that had a pump pre-wired for solar, but I can't find a link now....stupid internet is too big. ;)
Awesome instructable!
But to answer your question:
Algae, like all living things, have a life cycle. Although it is not what one might think. As algae reproduce they split into up to eight daughter cells, all internal. When the daughter cells get big enough the parent literally explodes and the remants, of course, will sink. This process is called flocculation.
In most circumstances these will decay and produce biogas, of which methane is a significant component.
Can any one help me out in some calculation work its really very urgent , please help me out ..... i need to consume 1932.3kg/hr of CO2 with the help of Algae in a pond (water) for example Raceway pond , so i need to know the specific area to construct that pond and its sizing and dimension (length,etc) and the quantity of water needed and amount of algae used so that it easily consumes the mentioned amount of CO2 rate per hour..... please help me out soon you can also drop your suggestion and questions if any my email id is : sudhirmalik2011@gmail.com ....i will be waiting for your reply soon and i'll be highly thankful to you, if someone can help please do tell me its very urgent....
Thank you
If you are attempting to scrub emissions from coal, internal combustion or other active generation source you'll need a bubbler tank design that captures 100% of the gas and bubbles it through enough to water to fully absorb the emissions.
Any significant design will requires substantial real estate and a non trival industrialized infrastructure.
Once you've captured you're 2000 kg/hr have you considered what you are going to do with algae, once its floculated? The problem of algae breeding isn't the breeding, its what to do with several tons of dead algae? The ponds are the start of your problem, not the goal...
Gathering and organizing the kind of information you are seeking is a non-trivial challenge. Such an undertaking of itself would be a time consuming (and costly) matter requiring the attentions of knowledgeable professional in the field. I would recommend someone but I don't know anybody in the field that does this sort of thing.
Gas uptake in air generally penetrates to a depth of about 6 cm which limits the depth of the tank and corresponding requires shallow pools with a broad surface area. This approach has its own limitations.
The NREL proposed a waterwheel type of assembly that rotated and circulated the water is travelled in long racetrack shaped pools. The UofA study expanded on that by using an aeration ramp and pouring water over it to get increased gas uptake with a significantly smaller surface area.
This design uses the air pressure both to aerate the tank as well as to rotate the algae population within it, in a production environment it could be used to very efficiently aerate a deep narrow in ground tank to obtain the maximum production per acre.
The pump in this design far exceeds the fundamental nature of the design, you could obtain improved efficiency with a larger tank which might help alleviate your concerns.
The water in the tank should rotate from top to bottom at least once every 6 seconds. A simple windmill lift that pumped water from the bottom and dumped it out, preferably in air, over the surface so that it falls through the air a little bit would be ideal.
Did you fill the bottles from the pond? Municipal water supplies are often treated so that tap water must be de-chlorinated otherwise it will kill the algae.
If you filled the bottles from the pond, put in a bit of fertilizer and ran the pump 24/7 I would expect you have a very healthy visible growth within a few days.