21
Experiment 4: Exploring the effect of varying fuel concentrations
You can make the different concentrations of ethanol fuel in the initial mix. For a 15% solution, add 9
ml of pure ethanol and fill water to the level of 60 ml. You can use a multi-meter or Horizon’s fuel
cell software adaptor product ref. FCJJ-24 to measure the voltage difference produced by the
fuel cell.
Through experimentation, you will find that increasing or decreasing the concentration of
the Ethanol does not noticeably make the fan run faster.
The reason for this is that the capability of the catalyst used on proton exchange membrane in the
fuel cell is limited. Similarly to many people going through a narrow door, the speed of people going
through the door is determined by the width of the door, but not by the amount of people.
Warning: The safe experimentation range for the Bio-Energy kit is within ethanol concentrations
ranging from 5-15%. Please note that the concentration cannot be higher than 15-20% otherwise it
will permanently damage the fuel cell.
Tip: If the device will not be used for more than one day, first pour out the solution in the container
and then purge out all the remaining solution in the fuel cell by pouring purified or distilled water in the
container. Make sure the purging valve is switched to the right side. Make sure all of the purified or
distilled water flows out of the container. Do not let the solution stay in the fuel cell otherwise it will
damage the fuel cell.
Experiment 5: Create electricity using different types of alcohol
Try using different types of alcohol such as wines made from grapes or rice instead of the
ethanol/water solution as described earlier on page 13.
Follow up the steps in the
experiment 1: create electricity from ethanol and water
to create
electricity.
Warning: 1. Alcohols used should stay within the range of 5-15% alcohol. If you are using an
alcohol that has a higher concentration than 20% please mix the adequate amount of water into the
alcohol to keep the required concentration range of 10-15%.
2. Using impure ethanol can damage the performance of the fuel cell. You may want to conduct
experiments using impure ethanol once all other experiments using pure ethanol are completed.
When you have finished the whole steps as in the experiment 1, you may notice the fan may run
very slowly, or may not run.
When using different alcohol types, this can affect performance. This
has to do with the purity of the solution, since some alcohols such as wine contain elements that
can clog the membrane on the fuel cell, limiting its permeability. Use a multi-meter or Horizon’s
fuel cell software adaptor ref. FCJJ-24 to measure the voltage or current produced by the fuel cell
under various conditions and slowing the speed of the chemical reaction.
See experiment 6: You will be able to prove that at different temperature conditions, different
voltages are produced, and you can plot these results into a chart to determine the optimal
temperature conditions for the fuel cell to generate the best results.
22