leoraanna
leoraanna asks:
Q:
Student wants to do 'pee power' for his science fair...
I have a student who wants to show that he can also create a fuel cell by extracting hydrogen from a synthetic urine to power a small car. I have told him no because it isn't something new- it's something that is already in deep research at nearby Ohio University and has been widely covered in the news. Also, I explained that being able to do it with a synthetic material doesn't prove the same idea (that you can power a car with urine) because it isn't the real thing and the costs and methods that would need to be put into place to make it possible would be outrageously expensive and difficult). He and his parents will not take no for an answer and I am running out of ways to say no. Are there any specialists out there who have more experience than I do that might have some good advice for me? Aren't there other liquids he could experiment with? Any other ideas that might be in this same realm of interest that doesn't involve pee? He's in middle school and that is not a time for experimenting with urine, real or synthetic.

I also don't want to say yes now that he's been bugging me for days because it sends the message that if you bother the teacher enough you get what you want. Even though I am running out of steam to keep saying no.
In Topics: Science fair
> 60 days ago

|
graham
graham writes:
Oh boy! Currently proposed hydrogen fuel cell cars are fueled with hydrogen which reacts with the catalyst in the fuel cell to produce electricity, which is used to power the electric motors. No ideas which I am currently aware of suggest making the hydrogen as part of the process inside the car. The production of the hydrogen is the most expensive (energy wise) part of the step. The most efficient way to get hydrogen at the moment is from mined natural gas.

So what could be the possible reasons why urine is preferable over water? Urine is 95% water anyway, and what is left changes depending on the person- mostly its urea ((NH2)2CO) and salts. Is the bonding strength of the hydrogen in urea lower than that of water? Would the salts make extraction of hydrogen via electrolysis easier?

Even if extracting hydrogen from urea was more efficient than water, you are right in that the collection of urea would be terrifically impractical and expensive. How do they propose to extract hydrogen from urine? How would it be different than water? Urine gives off ammonia, how do they propose to separate that out from the hydrogen? What about waste products from the process (ie, hydrogen depleted urine)? What would such a car smell like going by!

It is possible to get urea, which is used as a fertilizer, and mix synthetic urine- but I'm guessing you don't want to hear that.

My suggestion is to teach him about electrolysis and how to capture the resulting gases (hydrogen and oxygen). Tell him to use water, or compare water to something like Gatorade (which has more salt).

There is a lot of quack science on the internet to do with the extraction of hydrogen from water, so research with care. Good luck!

Did you find this answer useful?
2
yes
0
no
dees1
dees1 writes:
Since your student is into pee why not ask him to do another project about urine. You can ask him to try something new aside from getting fuel from it. Why not ask him to study how long a person can hold urine in the bladder. He can study which gender or age that can hold longer. He can also take note of the things people do to hold it longer especially when on a road trip. I guess that will stop him from bugging you.

Did you find this answer useful?
0
yes
0
no
Answer this question
Anonymous
Welcome!
Please sign in.
Not a Member? Join now!