Randy Vos
"Ever have one of those days where you couldn't hit the ground with your hat??" - Waylon Jennings
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erikem I would think that the low price of natural gas would make electrification more attractive (though maybe enough more attractive to justify the capital expenditures) as a combined cycle plant would be more efficient than anything that would fit in a locomotive. There would be transmission and distribution losses, but LNG has losses due to the energy needed to liquefy natural gas and energy needed to transport the LNG from the plant where the NG is liquefied to where it is used.
I would think that the low price of natural gas would make electrification more attractive (though maybe enough more attractive to justify the capital expenditures) as a combined cycle plant would be more efficient than anything that would fit in a locomotive. There would be transmission and distribution losses, but LNG has losses due to the energy needed to liquefy natural gas and energy needed to transport the LNG from the plant where the NG is liquefied to where it is used.
I think you raise a fascinating issue, Erik. Is the best way to use LNG by putting a tank on it in or right behind the locomotive? Or is it better used to generate electricity in some other space and string up wires to bring the fuel to the locomotive? No doubt there are some pros and cons here but I'm not sure they can be easily discussed outside of a particular context.
John
T. Boone Pickens and a lot of truckers think there is a significant opportunity for long-distance truckers to use LNG. The following link gives a lot of info:
http://www.cleanenergyfuels.com/products_services/trucking.html
greyhounds The puzzel of how this potential change over will alter the competitive balance between train and truck is interesting to me. I'm glad we got some discussion here.
The puzzel of how this potential change over will alter the competitive balance between train and truck is interesting to me. I'm glad we got some discussion here.
I've seen a couple of articles on LNG being available at a few truck stops, so it wouldn't surprise me to see a significant number of trucks running on LNG before the same fraction of locomotives start running LNG. Having an LNG "tender" would hold some advantages for locomotives over trucks.
- Erik
tree68 twcenterprises I'll admit, I'm no expert, but I expect when the engineer revs up a locomotive engine, it really only knows 2 modes - idle, or loaded. Actually, the engineer has eight notches to make use of, rather like the accelerator in a car or truck (which is continuous, not in steps). It's entirely possible that the locomotive might be cruising along in Run 4 and holding the desired speed just fine. It's not an all-or-nothing type thing. I'll grant that we're not a Class 1 running 100 car trains with 12,000 HP at the head end, but with 1750 HP and four passenger cars, I'm rarely above Notch 5, and that's accelerating out of a speed restriction, upgrade.
twcenterprises I'll admit, I'm no expert, but I expect when the engineer revs up a locomotive engine, it really only knows 2 modes - idle, or loaded.
Actually, the engineer has eight notches to make use of, rather like the accelerator in a car or truck (which is continuous, not in steps).
It's entirely possible that the locomotive might be cruising along in Run 4 and holding the desired speed just fine. It's not an all-or-nothing type thing.
I'll grant that we're not a Class 1 running 100 car trains with 12,000 HP at the head end, but with 1750 HP and four passenger cars, I'm rarely above Notch 5, and that's accelerating out of a speed restriction, upgrade.
Yes, I'm aware (most) locomotives have 8 throttle steps (notches), but let's say you are cruising along at Run 4, the engine is still generating maximum power for that throttle setting. Only if you disconnect the (electrical) load will the engine rev up without loading (high idle, sometimes used for building up air pressure). And yes, I'm aware there are exceptions to this.
In a truck, though, if I hold a throttle halfway to the floor, the engine will try to rev to a certain speed, regardless of the load, or lack thereof. Under a light load or no load, it will use only a little fuel, under a heavy load it will use much more.
Brad
EMD - Every Model Different
ALCO - Always Leaking Coolant and Oil
CSX - Coal Spilling eXperts
erikem Ken, I think you're confusing compressed natural gas (CNG) with liquified natural gas (LNG). The energy density (BTU per gallon) for LNG is lower than that of diesel fuel, but I doubt that it would be lower by more than a factor of three or so (Wackypedia says LNG has 60% of the energy per gallon as diesel fuel or about the same as LPG). - Erik
Ken,
I think you're confusing compressed natural gas (CNG) with liquified natural gas (LNG). The energy density (BTU per gallon) for LNG is lower than that of diesel fuel, but I doubt that it would be lower by more than a factor of three or so (Wackypedia says LNG has 60% of the energy per gallon as diesel fuel or about the same as LPG).
No, I was just using (probably badly) some LNG consumption numbers as provided by Conversion Technologies. I knew it was a SWAG. I'll do some more reading. It seems I need to.
gsrrmanLNG only costs about 49 cents per gallon vs 3.79 for a gallon of diesel. Even if you need 2 gallons of LNG vs 1 gallon of fiesle the cost savings will be#2.81 per gallon and tht is a lot of money. $
Your point is well taken. No doubt there will be conversion costs. But if that were a reason not to change railroads would still be using steam engines.
Actually, the engineer has eight notches to make use of, rather like the accellerator in a car or truck (which is continuous, not in steps).
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...
twcenterprises [snipped - PDN] . . . The biggest factors are, as noted, the lack of refueling infrastructure, and just as importantly, the lack of service facilities for maintenance and repair. Most mechanics are not familiar with LNG operation, so while they can do basic oil changes and such, they won't know how to troubleshoot a fuel related problem.
- Paul North.
I believe your logic and calculations and estimates are off. Way off. Now, I'll assume the part about needing 20,000 Gal of LNG to move a pair of SD-40's is correct. But the first bit of information that is missing is how much weight were they moving? How often did they start and stop? How long did they idle? These affect fuel consumption rates. And it's very likely they weren't running at full throttle the whole way.
Now, your information about highway trucks holding 100 gallons of fuel and getting 7 MPG is a reasonable assumption. Modern trucks can get in the 7 MPG range. But again, even at 65 MPH, the engines may be revving at a certain speed, but not needing to produce full power. The computers cut back on the fuel given to the engine to maintain a given speed (or the driver might). Running at full power, even in high gear at 65, a truck might be getting between 1-2 MPG under heavy load. But coasting downhill, it might be getting 99 MPG, since the computer is giving the engine very little fuel. Thus, the 7 MPG ends up being an average.
Simply comparing "3,000 HP locomotive to 600 HP truck" is not the same. Modern engines get *MUCH* better fuel economy, and the operating characteristics are vastly different. I'll admit, I'm no expert, but I expect when the engineer revs up a locomotive engine, it really only knows 2 modes - idle, or loaded. So the throttle compensates for that, by giving a little fuel, or a lot of fuel. On the other hand, a truck engine, the load is constantly varying, as the driver adjusts the throttle, the truck goes up and down hills, the driver changes gears, etc. So the fuel consumption rate varies, too, and the engine is designed to allow for that.
If I had to guess, I would say converting a truck from diesel to LNG would not result in that much of a drop in mileage, since many big cities do that with buses. The biggest factors are, as noted, the lack of refueling infrastructure, and just as importantly, the lack of service facilities for maintenance and repair. Most mechanics are not familiar with LNG operation, so while they can do basic oil changes and such, they won't know how to troubleshoot a fuel related problem.
gsrrman LNG only costs about 49 cents per gallon vs 3.79 for a gallon of diesel. Even if you need 2 gallons of LNG vs 1 gallon of fiesle the cost savings will be#2.81 per gallon and tht is a lot of money. $
LNG only costs about 49 cents per gallon vs 3.79 for a gallon of diesel. Even if you need 2 gallons of LNG vs 1 gallon of fiesle the cost savings will be#2.81 per gallon and tht is a lot of money. $
One thing that seems to escape from this conversation is Taxation on this Natural Gas Fuel ( at which ever delivery medium get the green flag.
Whether it is an Urban Legend or truth, I am not certain. But the information that I have heard for a long time is that Diesel Fuel Grades are the cheapest motor fuels to refine(?). That being the case. their cost is pushed up (currently, around here (So. Central Ks.) a gallon of diesel is $3.59.)
Natural Gas Fuel will be taxed by the States and Feds at their current or better percentages of value. IF and when it becomes a Motor Fuel and subject to Highway User Taxes. Try and keep a new and potentially lucerative revenue stream out of politicians hands...
The next hill to climb will be be what form will Natural Gas take to be marketed to the user pool.: LNG, CNG, ???. There will have to be an infrastructure to make it available to the users. And that Distribution network will have to be created virtually from scratch.
I wrote a paper on this in 1994 for presentation to the Transportation Research Board titled "Alternative Fuel-Powered Gas Turbine Locomotive. Fuels examined were Diesel#2.LNG, Methanol and CNG. Incidently LNG deliveres 115,000 Btu/gal as opposed to Diesel#2 at 129,700. (11% difference). I wrote another one the same year titled Comparison of Gas Turbine Locomotive Maintnance with other Technolgies (Presented to IAROO in Chicago. Looked at conventinal diesel locomotivesand equivalent gas turbine locomotives.
Copies are available
LNG in the rail industry will require dedicated fueling areas, just from the sheer volume of fuel required to replace the equivalent mileage operated with diesel fuel.
My carrier, over the past 20 years has minimized the number of dedicated fueling facilities on it's property. Instead they utilize mobile tank truck fueling , where the tank truck meets the locomotive consist at the tie up point of runs (Intermodal facility, power plant, grain facility) as well as meeting trains on the Main track at certain terminals. The name of the game is to keep the engines out of the shop for their 92 day inspection cycle - fuel them, sand them, service the toilet and consumable and change the brake shoes as necessary and keep them rolling. Of course the variety of engine malfunctions throw the proverbial monkey wrench into these plans from time to time and the engine must get routed to a shop for repair.
If LNG is consumed at 2 to 3 times the volume that diesel is - I am not aware of any tank trucks able to handle 20K to 30K gallons of any liquid that would be necessary to fuel a pair of AC's that each presently have 5K gallon diesel tanks.
Anything can be made to work with enough financial incentive, but a change to LNG would uncover a number of hidden costs, in the changes of operations that would have to factor into the entire financial package.
Never too old to have a happy childhood!
I found an interesting online article about LNG and the trucking industry:
http://news.nationalgeographic.com/news/energy/2013/03/130318-natural-gas-truck-stops/
Mileage on a single tank is far better than Greyhounds calculated but still not as good as diesel. Major reasons that the trucking industry might be slow to switch fuels include the lack of a developed LNG filling station infrastructure and the fact that , so far, the price differential between LNG and Diesel has not been as marked as had been predicated..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Greyhounds, you might find this post on the RBN Energy Blog interesting.
Methane Train Runnin'
Fred Frailey had an interesting blog post on LNG powered locomotives. I'm bringing it on this forum because I'd like to catch some trucker comments if possible. (If you're not a trucker, please chime in anyway if you want to.)
After reading Fred's blog I found this interesting information on the Internet:
http://www.energyconversions.com/loco2.htm#
LNG/diesel dual fuel locomotives obviously will work. And at the right differential between prices for LNG and diesel fuel they will pay off very well. But it takes a lot more gallons of LNG than diesel to do the job. (LNG is a lot cheaper - so even with more LNG gallons used things work out.)
Well, the truckers can run on LNG too. So how would a shift from diesel to LNG affect the competitive situation between truck and train? As I read it and as I see it, it will not be practical for truckers to use LNG for anything other than local deliveries and short hauls. Which will significantly tip the advantage to rail on all other distances.
According to the Energy Conversions data, when BN tested LNG locomotives it took 20,000 gallons of LNG to move two SD-40s (3,000 HP each) 800 miles. That works out to 12.5 gallons of LNG per locomotive mile. That's why BN had to add a tank car/fuel tender between the locomotives.
And that's the beauty part. Truckers can't add fuel tenders. A SWAG on my part is that a 600 HP highway tractor would use 1/5th the fuel per mile of a 3,000 HP SD-40. So the trucker would burn 2.5 gallons of LNG per mile.
Today, a trucker can run all day on 100 gallons of diesel. At 7 MPG diesel consumption he/she can generally drive their legal hours on a hundred gallon tank. Then they have to stop for a 10 hour rest period to stay legal. Well, when they stop for rest they can fill up the tanks and be ready to go on down the road after a comfortable sleep in the back of a truck.
But, by my SWAG, 100 gallons of LNG will only get them 40 miles before they'd have to stop and refuel. They cannot reasonably stop every 40 miles for fuel. They could go to larger fuel tanks. 600 gallon fuel tanks on highway tractors are not unheard of. But 600 gallons of LNG would only allow 240 miles between truck fuel stops. Every pound of fuel they carry subtracts one pound of freight from their allowable highway weight limited load. And even with 600 gallon tanks a truck could not make it from Chicago to Memphis without stoping twice for fuel. Now, with diesel, the truckers can run Chicago-Memphis non-stop.
Truck stop fueling facilities are going to have to be greatly expanded if truckers need to stop every 240 miles for a fill up - lots of new tanks in the ground to hold that much fuel. And lots of new pumps (or whatever a LNG fueling device is called.)
I don't think it's feasible for longer haul trucking to switch to LNG. The railroads can switch to LNG. This could be quite a game changer in favor of the railroads. It will be interesting to watch.
Any comments?
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