Washing Pollution Away with Golden Showers

By Lizzie Buchen | March 25, 2008 4:51 pm

The Friends-inspired rumor that urine can relieve a jellyfish sting provided more comedic value than useful first-aid advice, but there are actually many practical applications for that yellow waste product. Ancient Egyptians and Aztecs rubbed urine on their skin to treat cuts and burns, while the Romans used it as a bleaching agent for cleaning clothes and teeth. And now, it may help fight global warming.

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The key ingredient of urine—urea—is the basis of Mercedes-Benz’s clean diesel AdBlue technology. The urea-based solution (32.5 percent high-purity urea in demineralized water) is already available in Europe, and has finally made its way to American soil in the behemoth ML320 BlueTEC SUV. To work its magic, the urea-based solution whizzes into the exhaust stream, where it converts 80% of the nitrogen oxides into harmless ammonia. (Diesel engines produce less carbon dioxide than gas cars because they’re more efficient, but they unfortunately produce more nitrogen oxides. With this problem handled, more Americans would be able to switch over to diesel.)

In case you’re wondering (and really, who wouldn’t), peeing into your exhaust stream won’t work. While urea is the primary waste product of urine, it’s typically only 2–2.5 percent of the entire load.

  • don’t understand

    Urea contains nitrogen, right? So how does urea *remove* nitrogen oxides from the exhaust?

  • knows something

    @don’t understand: It recombines the NO and NO2 (the so called “NOx”, Nitrogene-Oxides) to N2 (pure Nitrogene) and H2O (Water). No NOx left. N2 is part of our breathing air. It is totally harmless and not harmful for the environment, while Nitrogene-Oxide, the “burned” Nitrogene, is.

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  • Teddy

    How is this earth friendly? If you read below the way they manufacture Urea (found in urine but not commerially produced from it)

    Commercial production of Urea:
    Urea is commercially produced from two raw materials, ammonia, and carbon dioxide. Large quantities of carbon dioxide are produced during the manufacture of ammonia from coal or from hydrocarbons such as natural gas and petroleum-derived raw materials. This allows direct synthesis of urea from these raw materials.

    The production of urea from ammonia and carbon dioxide takes place in an equilibrium reaction, with incomplete conversion of the reactants. The various urea processes are characterized by the conditions under which urea formation takes place and the way in which unconverted reactants are further processed.

    Unconverted reactants can be used for the manufacture of other products, for example ammonium nitrate or sulfate, or they can be recycled for complete conversion to urea in a total-recycle process.

    Two principal reactions take place in the formation of urea from ammonia and carbon dioxide. The first reaction is exothermic:

    2 NH3 + CO2 ↔ H2N-COONH4 (ammonium carbamate)
    Whereas the second reaction is endothermic:

    H2N-COONH4 ↔ (NH2)2CO + H2O
    Both reactions combined are exothermic.

    The process, developed in 1922, is also called the Bosch-Meiser urea process after its discoverers.

    The cleanest way to run cars is to use the methods already developed sitting on the shelves of the auto industries. Get the Major Oil Companies to stop paying the car manufacturers to continue to hide the clean ways to run cars. Unfortunately the big 4 oil companies are not bright enough to try to profit from other energy sources.

  • http://discoblog jim

    Teddy you were impressing me till you got to the oil co.auto manufacterers deal. obviously Gm wouldnt be broke if Mobil and others were paying them
    off the conspiracy train

  • http://discoblog jim

    that was get off the conspiracy train of thought how many others do you see out there??

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