Tag Archives: cars

Clean cars run on urine

How does this sound; using urine, the most abundant waste on earth, as the new fuel source? And, to catch two birds with one stone, it helps clean-up municipal wastewater at the same time. Urine-powered cars should be available in six months according to scientists from the Ohio University, who developed an electrolysis method to retrieve hydrogen from urine collected from livestock.


Hydrogen fuel cells are one the cleanest burning fuels ever developed. Hydrogen was, until now, taken out of water and then put into fuel cells as a gas that can power a vehicle.  The only emission that is said to come out of this fuel cell powered vehicle is water vapor. Urine’s major constituent is urea, which incorporates four hydrogen atoms per molecule – importantly, less tightly bonded than the hydrogen atoms in water molecules. By placing a special nickel electrode into a pool of urine and applying an electrical current, hydrogen gas is released. Once the urea is removed from the waste pool, a farm is left with water that is significantly less polluted than it was, with irrigation as one possible use.

One of the hurdles facing this alternative fuel source is that hydrogen gas requires high pressure and low temperatures to be stored. It becomes somewhat easier to store when it’s binded back to oxygen to create water, but even then it still requires large amounts of electricity to be released. The Ohio University scientists who developed the urine technology found that attaching hydrogen to nitrogen in urine allowed it to be stored without the strict requirements of ordinary hydrogen, and allowed it to be released with less electricity (0.037 volts versus 1.23 volts needed for water). A fuel cell, urine-powered vehicle could theoretically travel 90 miles per gallon according to the Ohio scientists.

 Some argue that hydrogen-fueled cars won’t offer a cost-effective way to reduce automotive air pollution or reduce
emissions of climate-changing carbon dioxide gas for at least several decades. Environmental scientist  David Keith is one of them. He doesn’t oppose the use of hydrogen fuel cells but argues saying it makes far more sense to first use this fuel in ships, trains and large trucks rather than cars. Such uses could achieve large reductions in air pollution without the need for the extensive hydrogen distribution infrastructure which would be required for refueling automobiles. Such an infrastructure is very expensive (approx $5.000 per vehicle or more), according to the researchers’ work. Also around 10-20% of the hydrogen would escape into the atmosphere. He says that if hydrogen fuel cells replaced all of today’s oil and gas-based combustion technologies, such losses would double or even triple the total hydrogen deposited into the atmosphere at the Earth’s surface.

Other researchers say that the use of hydrogen on large scale would oxidize when reaching the stratosphere, which would cool the stratosphere and create more clouds and, in effect, making the holes in the ozone layer larger and longer lasting. However it is not yet known on what scale this process will take place and there is also uncertainty how soil absorbs hydrogen from the atmosphere. The bottom line is that hydrogen could still be considered the far better option when it comes to competing with the toxic elements that are released into the air with gasoline burning cars. It might have its downsides but weighed against all the positives, they don’t seem to stand a chance.
It seems like we have a winner here.