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Discussion in 'Energy, Environment, and Policy' started by Robert.Boston, Mar 6, 2013.
WSJ today, front page of the Marketplace section. It's behind a paywall, but key points:
What is the energy density (per volume) of NG versus Diesel? Would they have to tow an additional car for NG, or would they liquefy it?
Robert, thanks for this update ... having lived in the UK for decades (and France) and loved the train systems there ... Eurostar, TGV etc. it's great they're trying to take a step forward.
However, it's a small one. And, of course it works!
Freight and passenger trains in Europe have been electrified (not all) for decades. Americans I meet who have sampled both cringe at the thought of mentioning the word "Amtrak".
@ElSupreme: the story states that BNSF would use LNG carried in a separate tanker car on each train. BNSF is also looking at ways of having dual-fuel capability, presumably because it's concerned that the LNG infrastructure won't be built out instantly across its rail system. The energy density of LNG is comparable to propane and ethanol but is only 60% that of diesel and 70% that of gasoline.[SUP] [/SUP] OTOH, a gallon of diesel costs about $4, and the energy equivalent of natural gas costs $0.48 (before liquifacation)
@sp4rk: The Acela (Amtrak's faster passenger train that shuttles between Boston and DC) is all-electric. Elsewhere, though, the density is so much lower than in Europe that the infrastructure costs would be prohibitive.
Yep. But the scale is a bit different. Europe has WAY more people living WAY closer together than the US. As Robert pointed out it makes sense in the NorthEast which is much more like Europe than the rest of the US.
Oy. BNSF is the railroad which looked into full-system electrification and realized that it made sense if diesel prices went up high enough.
However, instead they're investing money in quick fixes. The natural gas will have to be phased out again in 20 years as natural gas prices skyrocket; the supply is constricting fast, as fracking turns out to be a bust (wells run out after 3 years), and oil wells (the main source historically) run out, with no new source in sight. I realize it looks good short-term, but given the long lifespan of equipment in the railroad industry, I hope they have an eye on the time when they have to phase it out.
I'm curious--what means are used to extract power from the natural gas to move the train?
There are retrofit systems for diesels for LNG that essentially use port fuel injection to add the LNG to the air at the intake port and use recalibrated in-chamber diesel fuel injectors to put a small squirt of diesel into the chamber to ignite it. LNG itself isn't usable for compression ignition, but once ignited by a small amount of diesel fuel burns very well.