This instructable is based on work done by Bruce Logan and his team at Penn State University and on the microbial fuel cells built by Abbie Groff, a student at Conestoga Valley High School in Lancaster, PA. The research she performed with her MFCs helped her win the Grand Champion Award at the 2005 Lancaster County Science Fair.
Now to be completely honest the fuel cell we will build is not "purely" an algae fuel cell, it is a microbial fuel cell that uses anaerobic bacteria to decompose organic matter, in our case dead algae.
The fuel cell will consume the algae (or other organic material) with two significant by-products, electricity (always useful) and methane gas. In a production system the methane must be captured for further use for instance as fuel for a steam powered generator which processes its exhaust plume through an algae based (or other) exhaust gas scrubber.
In this design its very cleverly captured in the sealed anode and if you come up with some clever way to do something with it, I'd be very pleased to hear it.
Step 1: Bill of Materials
Drill or drill press
Razor knife or scissors
Hot glue gun
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:
- Two heavy duty plastic bottles with sealable lids. Wide mouth bottles are best choice for ease of inserting broad surface area electrodes.
- Low power aquarium air pump
- 1 x 2" PVC pipe 1-2 feet long
- 2 x 1 quart mason jars or similar
- 1 x 2" PVC Nipple or Sprinkler system riser
- 4 x PVC slip caps. You can probably get away with two, I use two for storing the salt bridge
- 2 x 1in square Silkscreen material or other nonconductive mesh
- Agar - 100g per Liter of water
- Salt - 400g per Liter of water ( 14 oz/Qt ).
- Carbon cloth or carbon paper
- Nitrogen for removing oxygen from water. This can be readily obtained from several sources locally and online.
- Welding supply places will have Nitrogen and Argon in tanks for various sizes. Around $35 for a small tank here.
- Local tire dealers. Local tire dealers often replace air in tires with nitrogen (for a fee). They will happily fill up your inner tube or inexpensive pressure tank (for a fee).
- Bacteria for a MFC can be obtained from several sources.
- Shultz Liquid Plant food