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Rocket Thrusters Used To Treat Sewage 73

Zothecula writes "Rocket engines are generally not thought of as being environmentally-friendly, but thanks to a newly-developed process, we may someday see them neutralizing the emissions from wastewater treatment plants. The same process would also see those plants generating their own power, thus meaning they would be both energy-neutral and emissions-free. Developed by two engineers at Stanford University, the system starts with the formation of nitrous oxide (N2O) and methane gas — something that treatment plants traditionally try to avoid."
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Rocket Thrusters Used To Treat Sewage

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  • by Wyatt Earp ( 1029 ) on Tuesday August 17, 2010 @01:28PM (#33278004)

    Because after a few minutes you just won't smell it anymore.

    I've worked in a sewage treatment plant doing process pipe design. You don't smell it after about 5-10 minutes.

  • by MadKatAlpha ( 1393157 ) on Tuesday August 17, 2010 @01:32PM (#33278058) Homepage Journal
    I'm confused that the article thinks that this is a new concept. Many wastewater treatment plants already make use of the methane gas for on-site power generation. For example, East Bay MUD [ebmud.com] in California generates 90% of its power requirements at the primary treatment plant.
  • by kg8484 ( 1755554 ) on Tuesday August 17, 2010 @01:58PM (#33278422)

    Probably because they approached the problem from the other direction (e.g. not looking for something to do with all that N2O, but looking for a source of the gas).

    Brian Cantwell, a professor of aeronautics and astronautics at Stanford, has created clean-burning rocket thrusters that run on N2O. "We wondered whether nitrous oxide could be exploited as an emissions-free source of energy," Cantwell said. "Since the product of the decomposition reaction is simply oxygen-enriched air, energy is generated with zero production of greenhouse gas. But first we needed to find a cheap, plentiful source of nitrous oxide."

    That source, of course, would be the wastewater treatment plants.

    Seems like Cantwell developed the N2O rocket first and then looked for where to get fuel. He got in touch with Craig Criddle, "a professor of civil and environmental engineering and senior fellow at the Woods Institute for the Environment at Stanford," and this idea was born.

  • Re:Aww, shit (Score:2, Informative)

    by 21mhz ( 443080 ) on Tuesday August 17, 2010 @02:49PM (#33279140) Journal

    * Environmentalists will shit when they see the carbon produced in the process

    These must be quite ignorant environmentalists. The carbon in biomass is fixed for short time periods, so burning it is still carbon-neutral.

  • by locallyunscene ( 1000523 ) on Tuesday August 17, 2010 @03:09PM (#33279452)
    Also, they mention that usually waste water plants try and limit NO2 and methane production by pumping air into the waste water.
    The benefits of this approach:
    1.) It reduces power needs substantially by removing the requirement to pump air.
    2.) It removes more nitrogen from the water in the process.(Hooray for not killing our oceans!)
    3.) The thruster can be as small as a basketball and handle all of the gas generated.

    You really should just read TFA; it's short, informative, and to the point.
  • by JSBiff ( 87824 ) on Tuesday August 17, 2010 @03:16PM (#33279546) Journal

    Urine is the body's way of disposing of excess nitrogen: Urea (one of the components of Urine) has the chemical formula: (NH_2)_2CO.

    Thus, there's plenty of nitrogen in the 'other organic materials' in waste water. Not every hydrocarbon is exclusively hydrogen and carbon - other elements can be present too.

  • Re:Aww, shit (Score:2, Informative)

    by Captain Centropyge ( 1245886 ) on Tuesday August 17, 2010 @03:58PM (#33280132)
    N2O doesn't contain any carbon. And as for the methane, when you burn it it gives off water and carbon dioxide. But the vast majority of the combustion reaction creates water. It's far better than releasing methane into the atmosphere without burning it. If environmentalists flip out over this, then fine... just release the methane into the atmosphere and see how happy they are. It's a much worse greenhouse gas than CO2.

    Besides, these "self-powered" plants will cut down on energy consumption and very likely offset any CO2 being given off, thereby making the EPA happier than just releasing methane or causing more pollutants from coal-burning power plants.

    As for oil companies... who even gives a shit about them, anyway? Why even bring them up? They have no place in this discussion.

Remember, UNIX spelled backwards is XINU. -- Mt.

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