Science Buddies: "Ask an Expert"

Hi I'm working on a project about biofuel and I was wondering how I could test if my biofuel works or not at home. Thanks!

Hi,

That's a great idea for a project! Could you post again with some information like what is your hypothesis, how you plan to test it, what organism you will use to produce biofuel, etc. There are so many different ways to produce 'fuel' biologically that it is impossible to answer your question without some details about what you plan to do.

Are you going to use yeast to make ethanol? Are you going to grow algae to make biodiesel? Bacteria to make hydrocarbons? These are just some of the organisms that researchers are testing now as sources of biofuel. The main questions being asked are what is the best organism in terms of what to feed it and how much 'fuel' it produces in relation to what it costs to grow it.

We can help you with specific questions on methods and experimental design but you have to decide on a hypothesis and a means to test it using the resources that you have. It is easy to come up with great ideas for experiments but for some things unless you have a lab to work in and the skills to use the instruments then they are not doable. Send us some specific ideas that you have for making biofuel and we'll tell you if it is workable.

Sybee

Sorry. So for my science fair I'm creating biofuel from banana peels and I've created it already but I'm not sure how to test out if it works and I really would like it to be at home because I don't have access to much.

If you could possibly take a couple of minutes to explain in detail exactly what you did I might be able to help you. Here are some of the questions we need answers to:

What organism did you use to produce the fuel--yeast?

How much of the organism did you use and how much banana peel?

Did you blend the banana peels and strain out the fibers?

How long did you let the fuel reaction continue?

If you used yeast did you measure carbon dioxide formation?

Did you stop the reaction by refrigerating it?

Post again with details and we'll try to suggest some way to evaluate your results.

Sybee

I used baking soda to fuel it. 2g of it and 3 banana peels. I blended the banana peels before I used it. Thanks for the help!

I'm having a hard time figuring out your project. I can't answer your question until I understand your idea. Can you please explain how baking soda plus banana peel is supposed to make a fuel?

Sybee

I blend the banana. Filter it. Add baking soda and compress it and you get a coal of biofuel and it's the coal I need to test. If you still can't figure it out I'll seek help form elsewhere. Thanks!

Sorry for the confusion. A compressed 'coal' of banana peel is not what most scientists would consider biofuel. The only way to test it for fuel that I can think of--hopefully some of the other experts can also offer suggestions--would be to burn it and measure the heat produced. Here is a method for doing that:

https://www.sciencebuddies.org/science- ... p012.shtml

Ok thanks. I was also wondering if doing these steps but with different fruit/vegetable waste would work out? Because now I'm thinking of comparing the different types of waste produced biofuels.

Testing a variety of plant materials as fuel would be better than doing just one.

Have you tried burning the banana peel 'coal'? It will have to be really dry in order to burn and if it doesn't then I don't know how you will measure its fuel content.

How much baking soda did you add? If there's too much then the banana peels probably won't burn at all.

Let us know what happens.

Sybee

Thanks. I haven't tried burning it yet but do you think that by doing the same steps that I did for the bananas, the 'coal' from other plant materials will be made?

If your idea is to use fibrous waste from fruits or vegetables then you need to choose things that do have a reasonable amount of fiber. I don't know if this will work. Choose something else like apple peels and see if you can turn them into a fuel. Scientists have to test a lot of things sometimes before they find one that works.

I'm not sure how much I can help, but if you have specific questions I can try to find an answer.

Good luck!

Sybee

Thanks for all the help! I'm doing the write up now and I just wanted to add how is it that burning the coal can test for fuel? Also I used bananas because they add to the waste and they are not used for much but I was also wondering if there was a scientific reason for why banana peels will work for biofuel? Also can you please hurry, my project has already been delayed. Sorry for any inconvenience.

You're welcome!

In order to test something as a fuel you need to burn it to heat water. The increase in water temperature for a specific amount of fuel, such as your banana 'coal', tells you how good a fuel it is. This was explained in more detail in the link I gave you earlier: https://www.sciencebuddies.org/science- ... p012.shtml

Banana peels contain cellulose, starch and sugar and all of these will burn when a flame is applied. Most plant materials will burn if they are dry enough.

If you have more questions, let me know.

Good luck!

Sybee