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Discussion in 'Electrical Engineering' started by Bill, Feb 15, 2010.

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  1. Bob F

    Bob F Guest

    Nope. Just you.

    Methane produces less CO2 per unit of energy produced than coal or gasoline.

    http://www.engineeringtoolbox.com/co2-emission-fuels-d_1085.html

    Plus, recovering methane and using it to create energy prevents the methane from
    escaping to become a greenhouse gas. The energy produced is a bonus.
     
  2. Totally beside the point; the news report said specifically that
    capturing the methane and burning it would mean that the carbon in the
    methane wouldn't be released into the atmosphere. The CO2 released when
    the methane is burned is most definitely a greenhouse gas. (Remember the
    formula from high school chemistry? CH4 + 02 --> CO2 + H20)

    Try to read more carefully.
     
  3. Bob F

    Bob F Guest

    Try to write more carefully then.

    "this would reduce carbon dioxide emissions" is what you said. And it clearly
    will, by reducing the production of the equivalent power burning coal. Less CO2
    is produced with the methane.
     
  4. Except that this is the wrong comparison: the methane is being used to
    power garbage trucks, so the proper comparison would be with gasoline,
    diesel or propane.

    So the only carbon that's being kept out of the atmosphere is the
    marginal difference between the carbon emitted by burning one of these
    fuels and the carbon emitted by burning methane. Not at all what the TV
    news report said.
     
  5. Yes. Most educated people know that CO2 is essential for life on earth.
    (It's what green plants take in.) The thing is to have just enough, but
    not too much, of it.
     
  6. People educated in government schools? I once had a respiratory
    therapist tell me that CO was carbon dioxide. I could not get
    her to understand that CO is carbon monoxide. I hope I don't
    wind up in the hospital where she works.

    TDD
     
  7. I take "educated" to mean at least some post-secondary education, let's
    say a bachelor's degree. And not at some diploma mill where the only
    goal is to get a barely passing grade so one can get into business, real
    estate, or some other money-grubbing profession.
     
  8. bud--

    bud-- Guest

    Nope, significant *carbon* is being kept out of the atmosphere. As Bob
    said you are *substituting* methane for other fuels instead of just
    having the methane (a greenhouse gas) leak out to the atmosphere.
    Greenhouse gas emissions are clearly reduced - the major reason for
    using the methane.
    That is assuming you heard right. If the report said "reduce carbon
    emissions" [or greenhouse gas emissions] it would accurately describe
    what is happening.

    "Reduce carbon dioxide emissions" is a misstatement of the major benefit
    [but true using Bob's reference]. IMHO as misstatements go, it is
    relatively minor. There is a major benefit in using the methane.

    In addition, if I remember right, methane is a more powerful greenhouse
    gas than the CO2 that the methane is turned into - an additional
    excellent reason to use the methane.
     
  9. Bob F

    Bob F Guest

    I was educated in government schools and got a fine education. As were a huge
    number of
    Americans.

    One idiot shouldn't condemn a whole system. By the way, what public school did
    that person go to?
     
  10. Bob F

    Bob F Guest

    So, if the methane had just wafted off into the atmosphere, you are saying the
    carbon wouldn't have ended up in the atmosphere?
     
  11. What are you, an *intentional* fucking idiot? Really.

    READ WHAT I SAID. Let me paraphrase and try to explain, this time with
    SMALLER WORDS that you might UNDERSTAND.

    The carbon contained in the landfill will reach the atmosphere in both
    cases: if the methane is allowed to waft into the atmosphere, or if it
    is captured and then burned in an internal-combustion engine (in a
    garbage truck). THE CARBON WILL ENTER THE ATMOSPHERE IN EITHER CASE. If
    it's captured, the release of the carbon is merely delayed.

    And yes, there may be a SLIGHT reduction of the total amount of carbon
    released by burning methane as opposed to other motor vehicle fuels
    (gasoline, diesel, propane), but the reduction is marginal at best.
     
  12. daestrom

    daestrom Guest

    But pound for pound, isn't methane a 'worse' green-house gas than CO2?
    I understand that methane released into the atmosphere is more
    detrimental to 'global warming' than CO2.

    So converting the methane to CO2 before releasing it still puts the same
    amount of carbon in the air, but in a form that is less detrimental.

    daestrom
     
  13. That's another issue entirely. So far as the "badness" of CO2 vs.
    methane goes, I simply don't know. If you say methane is worse, I'll
    have to take your word for it.

    But even if that's true, it's simply another *marginal* difference.
    Doesn't change the point I was making, which is that the mainstream
    media often portrays things like this (capturing methane from landfills
    and burning it) as somehow completely *eliminating* that release of carbon.
     
  14. Guest

    Guest Guest

     
  15. Guest

    Guest Guest

    ----------------------
    Nice but illogical.

    Burning natural gas releases y units of carbon and at the same time land
    fill methane wafting into the atmosphere releases x units of carbon
    sum x+y
    Burning the landfill methane releases x units of carbon but also means that
    this replaces the burning of natural gas or other fuels.
    sum x units
    x+y > x

    By using the methane, you are eliminating the carbon introduced into the
    atmosphere by burning other fuels.

    Essentially, assuming equal conversion efficiencies (admittedly not true but
    also not actually germane to the issue) using the landfill methane alone
    produces half the carbon that would be released by burning natural gas AND
    letting the methane "waft into the atmosphere".

    The "illogic" is that you are comparing one "carbon source " with the other
    "carbon source" which is not the situation, rather than one such source
    with both such sources -which is the situation.
     
  16. I'm not sure, I'm more worried about where she was trained as a
    respiratory therapist.

    TDD
     
  17. Got to admit you seem to have hit the nail right on the head here. I
    accept your explanation.

    But I still say the TV news report I heard was highly misleading. They
    didn't explain things the way you did, and left the impression that the
    methane capture would somehow result in ZERO carbon being released.
     
  18. daestrom

    daestrom Guest

    But for a non-scientific publication by a non-science journalist, it may
    be the point they were going for.
    Here's the EPA's and IPCC's 'word' on it. Methane has a GWP more than
    20 times that of CO2 (see sidebar in middle right side of page)

    http://www.epa.gov/climatechange/glossary.html#GWP
    Reducing the Global Warming Potential by a factor of 21:1 may not be
    'eliminating' it, but it is far more than just a 'marginal' difference.

    daestrom
     
  19. Zero *additional* carbon, if one argues that "additional" means
    "compared to the release due to the methane". But the methane is
    anthropogenic, no? Yes, there are other sources of methane that are not
    human-caused, but you've got to admit that throwing garbage in a big pit
    is a human activity, yes?

    Again, at the cost of belaboring this point, the news report left the
    impression that capturing the landfill gas would *eliminate all* carbon
    emissions from the trash. It would do no such thing.
     
  20. bud--

    bud-- Guest

    Don was the third person who made essentially the same point. We have no
    idea whether the news program did or not - you seem to not catch on.
    Using the methane results in ZERO *additional* carbon being released.

    Your post that started this said "reduce carbon dioxide emissions". If
    you misheard and they said "reduce carbon emissions" the report was
    accurate. If they did say "reduce carbon dioxide emissions" the report
    misstated the effect, but was close - as understanding of science goes
    today. Using the methane reduces greenhouse gas emissions. Three people
    who posted here understood that and tried to tell you, starting with
    Bob. Your understanding of science, at best, does not appear to be
    better than the news program.
     
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