#27: Banana Peels to Potassium Metal (Part 1)

It's common knowledge that bananas are a great source of potassium. What people don't know is that they contain much less of the mineral than many other foods such as beans or potatoes. Nonetheless bananas have a lot. Interestingly, the peel contains roughly 40% or 200 mg of the fruit's potassium content. This is high when you consider the peel's low volume and low weight. Upon learning these facts myself, I began to wonder if raw potassium could be obtained from banana peels. As usual, I asked the internet. To my astonishment, I found very little. The closest I got was a video that showed how to extract a small amount of potassium carbonate (K2CO3). While this wasn't exactly what I was looking for, it got me thinking. What if I could I go beyond potassium carbonate?

My challenge was to devise a series of chemical reactions that would eventually get me to pure potassium. Through research and reasoning, I developed a plan and put it into action. Here is the first installment of my fascinating experiment:

1. Over the course of two months, I collected peels. I forced my siblings to eat as many bananas as possible. I guess this made them my lab monkeys. 
2. As I received new peels, I placed them across a bamboo pole that I hung in the garage. Within a week or so, they turned brown and dried up. 
3. When I reached 40 dried banana peels, I removed them from their rack and placed them in a small brick oven that I made. Next, I burned them with a blowtorch. This was difficult because the peels did not burn easily. Eventually, I had reduced the pile of peels to a cup of ash. 
4. Back in the lab, I added the banana remains to a large beaker and poured in an equal volume of water. With my butane burner on high, I brought the mixture to a boil. As the liquid bubbled, the potassium, in carbonate form, dissolved in the water while the rest of the ash did not. 
5. Through repeated filtering, I removed the undissolved ash. This left me with a dilute solution of potassium carbonate, among other trace compounds.  
6. By boiling down the solution, I obtained impure potassium carbonate in solid form—the first step toward potassium metal. 

Stay tuned for part 2 of this experiment.

It's well known that bananas are high in potassium, the question is, can the potassium be extracted?

To dry the banana peels, I hung them over a bamboo pole in my garage. 

While it took quite a long time to burn all 40 banana peels, wielding a blowtorch is never boring.