What about running your home off this technology? Is there something special about a car that makes it a more logical choice than a home for this type of system? I guess in a home the hydrogen fuel cel would be powering a generator. Any ideas, anyone?
Excellent point! Maybe a day of urine from one person will power a laptop for a month.
Maybe a household of four people will be able to power half their power needs.
ZeroFuel is a mixture of water and carbamide, or urea.
Ah, so no Na, P, K, Ca...It'll take some energy to remove those, eh?
Urea has a specific heat of cumbustion of -10.56 kJ/g. Assuming 2 kg of urine produced per capita per diem, and 5wt% urea content, we have 100 g of fuel, which burns for an absolute maximum of about 1,100 kJ. This energy is equivalent to 0.011 gallons of gasoline, so if the car pictured is as efficient as a 60 MPG car, it can take a family of four almost 3 miles per day on the urine they produce.
Unless the hydrolysis of urea consumes some energy (hint: it does), or unless the engine will choke on salt or ash or sulfur or...
I would bet money the intent is to power the car with synthetic urea, effectively a gas-to-liquids scheme based on the fischer-tropsch process. I also imagine it only works well when the water is mixed in equi-molar, i.e. 76.9 wt% urea.
This podcast covers a LOT of different topics!
As mentioned at the beginning of the podcast: email signup.
We start off reviewing the movie "Food Matters". The premise is that many diseases can be resolved by food choices. And this has been discussed several times at the forums. A good start is my thread on eliminating medication with polyculture; and the thread about beating cancer;
We talk about raw food; local food; the missoula urban demonstration project; composting toilets; outhouse; urine diversion; women peeing outdoors; hugelkultur; rain barrels; greywater; commercial compost; art ludwig; pee powered cars; jean pain technique; poop beasts.
"Urine’s major constituent is urea, which incorporates four hydrogen atoms per molecule — importantly, less tightly bonded than the hydrogen atoms in water molecules.
Botte uses electrolysis to break the molecule apart, developing an inexpensive nickel-based electrode to efficiently oxidise the urea.
To break the molecule down, a voltage of 0.37V needs to be applied across the cell, which is much less than the 1.23V needed to split water.
“During the electrochemical process the urea gets adsorbed on to the nickel electrode surface, which passes the electrons needed to break up the molecule,” Botte told Chemistry World journal."
"People have known for a long time that you can generate hydrogen easily by running a current through water to split it into its component parts — oxygen and hydrogen — using a process called electrolysis. The problem is that the amount of energy needed to split the water is relatively large and the materials required are very expensive (although last year some MIT scientists created a brand new cheap catalyst that they say changes all that).
Urine to the rescue. Now some researchers at Ohio University have found that urine makes a much better starting point for generating hydrogen than water. The hydrogen found in urine is bonded much more loosely than in water. So loose, in fact, that by using simple and cheap materials hydrogen can be generated from urine using 1/3 of the voltage needed to make hydrogen from water."
I think the crucial bit is "by using simple and cheap materials hydrogen can be generated from urine using 1/3 of the voltage needed to make hydrogen from water"
Emerson White wrote:
Where do we get the urea from? Do we make it with fossil fuels or do we divert the urea from farm animals that we now put on our fields as fertilizer?
I'm not going to admit how many 5 litre containers of urine I have in the back yard waiting to be taken to the farm to be added to the compost heap. I can't find the reference now, but I'm sure one of those links I just checked out said that you could do about 40 miles on one day's pee. I could probably spare that much every week or two for a trip to town.
Edit... It was this link http://www.wired.com/autopia/2009/07/pee-powered-cars and it said that "I believe we could have pee-powered cars capable of 60 miles per gallon on the road within a year" It would take me a couple of days to produce a gallon of pee if I had no help from the rest of the family.
But does anyone know if 60 miles a gallon is a reasonable guestimate? I mean, most of pee is water, right? How much urea is in it? How much hydrogen could be extracted from it? And how does that relate to 'miles per gallon'?