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More info (Aug 2017) about LNG and GHGs

Discussion in 'Energy, Environment, and Policy' started by AudubonB, Aug 17, 2017.

  1. AudubonB

    AudubonB Mild-mannered Moderator Lord Vetinari*

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    I just came across some data regarding what is effectively the cleanest of commercial hydrocarbons - natural gas.

    As its transportable form - LNG - this is an increasingly important global commodity. LNG tankers are transporting product from port hubs as far as halfway around the world.

    LNG is not, however, so durable a product as one might hope. The gas is chilled to approximately -200ºF/-130ºC (at atmospheric pressure it boils at -260, but it is transported in pressure vessels so a slightly higher temperature is available).

    There is, though, always some boil-off. The world's current tanker fleet boil-off average is .15% per day; new ships are achieving .1% and the best ship in the world has achieved .08%.

    Now: the average length of trip from the biggest US LNG port - Sabine Pass in Louisiana - is 7,500 miles which, at the industry mean of 14.3 knots, takes 22 days.

    This gives us transit boil-off totals of 3.3%, 2.2% and 1.8% given the data above.

    All of that raw methane goes straight into the atmosphere. And that's a lot of cow farts.

    Some of the above information came from here: The Gas Tankers Lurking at Sea Looking for a Better Deal
     
    • Informative x 2
  2. doug

    doug Administrator / Head Moderator

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    You'd think they'd be able to use that boil-off as propulsion fuel, or in a small turbine for electrical. At the very least, burn it.
     
  3. AudubonB

    AudubonB Mild-mannered Moderator Lord Vetinari*

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    That would make sense iff the ship's owner/operators and the LNG owners' interests coincided. Otherwise...guess what?
     
  4. doug

    doug Administrator / Head Moderator

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    Well the tankers are carrying cryogens, so they're already fairly specialized. Cutting waste tends to save money, so it can be a win for all involved.
     

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