Fuel cell and hoffman apparatus

[gkkandru]

I am building a Hoffman apparatus and connecting it to a fuel cell and am planning to measure its electrical output. However, I do not know how to build one inexpensively. Do you know if there are any cheap substitutes for the PEM in the fuel cell itself and how to make a hoffman's apparatus cheaply. What type of materials could I use other than glass and how could I make it myself. In addtion, I am varying the salinity of the solution in the liquid but do not know exactly what liquids to use. I want to put electrolytes to theoretically increase the rate of the electrolysis but do not want to compimise the fuel cell. I also want whatever liquid used to be relatively simple so that it can be used in a "real world example" in that this kind of technology can be practical. Please help me and if possible provide me with a mentor in this area.

[davidkallman]

Hi gkkandru,

Wow, you know a lot, and have thought a lot, about Hoffman apparatuses!

To get started answering your question, I input "inexpensive Huffman apparatus" to answers.com
You can also try "low cost Huffman apparatus".

Do any of the output provide what you're looking for?

There does seem to quite a large number of false hits relating to Huffman encoders, so you may need to add more terms to specify the type of Huffman apparatus you're looking for.

I don't think I would be a good mentor since this not my area of expertise. Maybe someone else on Science Buddies can help.

[barretttomlinson]

Hi,

Here is a writeup on how to do electrolysis without a formal hoffman apparatus:

http://www.woodrow.org/teachers/chemist ... exp27.html

Here is a survey of different fuel cell types:

http://www1.eere.energy.gov/hydrogenand ... types.html

http://americanhistory.si.edu/fuelcells/basics.htm

Here are possible idea sources for fuel cell experiments:

http://www.cleanfuelcellenergy.com/new_book.html

http://fuelcellstore.com/products/helio ... /INTRO.pdf

This thesis might offer a good alternative for your project:

http://etd.lsu.edu/docs/available/etd-1 ... hesis2.PDF

Locate page 64 of this eBook site to read about student science project on a hydrogen-oxygen fuel cell:

http://science-projects-guide.com/2005/ ... -ebook/29/

I saw a Mr. Wizard show sponsored by Westinghouse in about 1958 that featured a fuel cell made from a paper cup( used as the air electrode) and ran on methanol/KOH if my memory is correct. It lighted a small flashlight bulb and ran a very small motor. Unfortunately I cannot find a description of it despite looking for an hour on Google.

Even a small effort with Google will locate fuel cell kits that are available for purchase. You should also easily be able to locate Nafion membranes for sale, should you wish to make your own fuel cell stacks,

I hope these resources help answer your questions! This sounds like a really neat project. I hope you really have fun with it.

Best regards,

Barrett Tomlinson

[gkkandru]

First of all, thank you for responding to my post. I appreciate your advice very much and am looking at the sites you have provided me.I plan to make my own fuel cell so that it will show my understanding of how it works and I want to be able to manipulate it to fit in with my Hoffman's Apparatus. In regards to the Nafion membrane, I have looked into it and it seems expensive. I was wondering if there might be a replacement to that specific component of the fuel cell. Also I was wondering about the catalyst in the cell. I have looked into it a little and have seen some kind of "carbon paper" but am not really sure what it does other than increasing the surface area for the reaction.

[barretttomlinson]

Hi,

I found this do it your self site - I cannot vouch for how well it works:

http://blog.makezine.com/archive/2006/0 ... d_aid.html

Here is a do it yourself version of the very first fuel cell discovered:

http://sci-toys.com/scitoys/scitoys/ech ... _cell.html

(Note only platinum or platinum coated wire is required, not nafion membrane, but recognize it is not going to produce much power.)

Here is a video of a way to build a small fuel cell without using the Nafion membrane:

http://brainstuff.howstuffworks.com/200 ... fuel-cell/

And, a little off-topic, a site on building microbial fuel cells:

http://www.engr.psu.edu/ce/enve/mfc-Log ... akeone.htm

I hope you find these useful. The bottom line here is that you are probably going to have to use platinum as a catalyst in the cell to get much power out of it, and platinum is expensive, though you should need very little of it.

Good luck!!

Barrett Tomlinson

[gkkandru]

I have been able to set up a system where I have large gradjuated cylinders and in each I have and insulated nichrom wire with the ends of it is bare. I am using the wire as an electrode to seperate the water into hydrogen and oxygen gas but am having some trouble. The electrode is inside an upside-down burette where the gasses will theoretically be created and rise through the tubing and into the fuel cell. However, I am not seeing any bubbles, as is characteristic of gas formation and i have not recorded any electrical output from the fuel cell. I have checked the current to see whther it was running, amped up the voltage for electrolysis to 12 volts and still have not noted any gasses or electrical output after wiating for about 40 minutes. Do you know what might be going on?

Thanks for your help,

GKKandru

[barretttomlinson]

HI,

Have you measured the current through your electrolysis circuit? I am guessing that it is nearly zero. This might be caused by using rather pure water in your apparatus. You need ions to conduct current between the electrodes. The usual solution is to add some salt or dilute acid(hydrochloric or sulfuric) to the electrolysis cell.

Best Regards,

Barrett Tomlinson

[Craig_Bridge]

The usual solution is to add some salt or dilute acid(hydrochloric or sulfuric) to the electrolysis cell.

CAUTION: Anything that might provide a Cl ion is a BAD choice. You do NOT want to risk generating poisonous Cl2 gas by electolysis.

Dilute sulfuric or nitric acid or any base with an OH ion or other salts that do not contain negative ions that form undesirable gases.