Erik_Mag With the ignition temperature of methane running just above 1,000F, and the rapid dispersal of LNG vapors, it doesn't sound like much of a safety problem.
It's Schwan's, which also uses LP.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
tree68 Although some mornings in late January in the north country sure feel like it...
Although some mornings in late January in the north country sure feel like it...
Cold enough that a LNG bath sounds warm?
Reminds me of a scene in a comic book with people in a desert:
"Man that sun is hot!"
"That's the moon. When the sun comes up you will feel like cooling off in a blast furnace."
I believe there is a door-to-door food sales company that uses LNG to power their trucks... Not that the public realizes that...
Interesting. I've seen LN2 dewars that would make reasonable LNG tank (LN2 is colder than LNG). With the ignition temperature of methane running just above 1,000F, and the rapid dispersal of LNG vapors, it doesn't sound like much of a safety problem. I would expect methane to be a very clean burning fuel - spark plug and oil lifetime should be pretty long.
SD70DudeAnhydrous ammonia and liquid/compressed chlorine scare me more than anything else.
As well they should. Nasty stuff if they get loose in quantity.
Erik_Mag ...but there is no place on earth that gets cold enough for methane to turn liquid.
I worry more about my drivers in traffic hauling acid and chlorine than anything that is hauling LNG. The NIMBY's and Bananas are just screaming at stuff because they are moronic idiots looking for their next bogeyman to be scared of.
I switch all this stuff on a daily basis (well, not LNG, not yet anyway).
Anhydrous ammonia and liquid/compressed chlorine scare me more than anything else.
CN has been running unit trains of LPG (propane) for a couple years now, and for a long time we've had a daily train from the Edmonton area to Winnipeg that is primarily composed of ammonia, LPG and other 'goodies'.
Greetings from Alberta
-an Articulate Malcontent
While I'm sure that Larry (Tree) and OM know, the difference between LNG and LPG is that the critical temperature for propane is almost 200F, the critical temperature for natural gas is colder than -150F. What this means is that propane will liquify under pressure at any ambient temperature on the surface of the earth with the exception of geothermal hot spots, but there is no place on earth that gets cold enough for methane to turn liquid.
One of my thoughts for LNG tank cars is to have a cryocooler powered by methane vented from the tank. The cryocooling would reduce the amount of vented methane and the engine powering the cryocooler would burn off what methane was vented. Not sure how practical this would be....
The thought of an LNG tank car caught in a fire does concern me, but not as much as a hopper car loaded with ammonium nitrate caught in a major fire.
Overmod Don't think I was castigating you in person either -- of all the people here you're likely the most qualified to assess and deal with emergency situations involving these things. I wanted to establish, perhaps more forcefully because the statement came from such an expert, that the two materials behave very differently in accidents, before folks like the OP 'concluded' wrongly that LNG is a severe transport hazard.
Don't think I was castigating you in person either -- of all the people here you're likely the most qualified to assess and deal with emergency situations involving these things. I wanted to establish, perhaps more forcefully because the statement came from such an expert, that the two materials behave very differently in accidents, before folks like the OP 'concluded' wrongly that LNG is a severe transport hazard.
NP - your correction was appropriate and your post was informative.
OvermodThat has no relevance in this thread whatsoever.
My bad - I misread LNG as LPG. You are absolutely correct.
tree68After the initial onslaught of LPG incidents (Oneonta, Kingman, et al), there haven't been many major LPG problems.
You might as well discuss undegassed Bakken crude in a discussion of transporting Bunker C or residual in tank cars.
LPG is only 'liquefied' under pressure, and in consequence among many other things is a BLEVE hazard. LNG cannot be that under any circumstances achievable even in railroad accidents, as the amount of pressure applied to sufficient volume over time to heat the liquid out of cryo is orders of magnitude too great while assuming structural integrity orders of magnitude higher than achievable.
In my experience the chief risk in LNG transport is the creation of an established pool fire. As you can see from videos investigating these (some of which have been posted in other threads here) these are relatively slow to develop and, while very hot, not that difficult to extinguish.
After the initial onslaught of LPG incidents (Oneonta, Kingman, et al), there haven't been many major LPG problems. The fixes instituted following those incidents have been quite effective.
The issue is that the behavior of the cars following a derailment is only so predictable. No matter what safeguards one puts in place, chance will find a way to defeat them.
The idea of individually monitoring cars is not too outlandish - the technology certainly exists to do so in a number of ways.
But we must realize that LPG tends to be seasonal - many of the cars spend half the year in storage on unused backtracks. Any sort of active monitoring (like is used for reefers) must take that into account. For that matter, providing power for such monitoring must be considered as well.
SAMUEL C WALKERThis might overcome serious concerns for LNG transport.
Of course, cheap 'commodity' car tracking is now easier and orders of magnitude cheaper than what, say, Olin uses, and metadata transfer of a few things like boiloff rate becomes almost trivial to add to a tracking signal. For a competent programmer, even something like using pager frequencies as a 'command' channel to request or even configure onboard sensing or control equipment is not difficult even if there is no good way to provide 'uplink' via unused bandwidth or channels in the radio or PTC architecture.
Note that in most cases a problem with onboard LNG condition monitoring could be pretty well handled with lights, whistles, and some kind of transponder of the general "I've fallen and I can't get up" sort of action. Even if something knocked or shot the boiloff relief valve off one of these cars, the atmosphere will not support critical-mixture explosion over the pool even if the blanket gas is exhausted. A good self-contained indicator 'suite' would be valuable to first responders assessing any sort of severe wreck, certainly much more than some encoded datastream using what are likely to be fragile and exposed antennas for transmission.
No need for hysterical safety measures at all ... although I would not object to FRA or PHMSA requiring some sort of smart monitoring for all 'hazmat' cars.
No need for hysterical safety measures at all ...
Perhaps the best way for LNG by rail will be for active sensors on the tank at all times. That way a problem will be addressed prompty and early avoiding a catastrophe. Otherwise, the tank will be a dumb tank car. Tank cars should be outfitted to be smart and confirm that the tanks car is fit. This might overcome serious concerns for LNG transport.
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