Anybody know how sulfur is kept from solidifying inside a tank car or is it allowed to solidify and then is heated to aid the discharge process? Here in Florida, we get unit trains of molten sulfur from out west that arrive with either BNSF or UP power. Sulfur is used in the phosphate manufacturing process that takes place in central Florida’s famed Bone Valley and boy do those trains really stink. [xx(]
I know of no technology that will keep anything molten in that state except insulation and/or very short trips. Most things that precipitate or freeze in transit are heated by steam applied to either external or internal, to the tank, heater coils. I have heard of, but not seen, electrical heating systems used to thaw pitch loaded in tank cars. The power is supplied from a fixed source.
Mac
Former Bureau of Explosives Inspector
Sulfur cars are insulated, but I’m pretty sure that steam in the coils has to be used to unload the cars regardless. I don’t remember enough about the expansion/contraction properties of sulfur to know whether they have to anticipate those possibilities when the temperature changes.
Fortunately, even though our windows aren’t very energy-efficient, I don’t smell much through them. We get plenty of sulfur cars, both loaded and empty.
Tank car class 111A100W1 are insulated tank cars with heating coils between the inner and outer shells to keep the sulphur in a molton state. There are 2 varieties with capacities of 13,470 and 15,100 gallons.
The term “molten sulfur” is actually somewhat deceiving. Yes, it is splash-loaded hot, but is allowed to cool while the car is in transit. Much of the sulfur heading for Florida comes from from the Alberta Oilsands, or other large oil refining centres. Molten Sulfur is actually one of the few commodities (transported in tankcars) that can be loaded to 286 GRL. Most other commodities (and pretty much anything regulated or pressurized) has a 263K limit imposed. Newer 286 cars have a capacity around 15,000 gals, whereas older cars are of smaller capacity. The cars are insulated, and when arriving at the destination, steam fittings are connected to the car to return the sulfur to a liquid state.
To clarify, the tank is the inner part that holds the commodity, and the outside, visible, exterior is the jacket, constucted of a much thinner steel (so if you ever see an insulated tankcar that has been derailed and then rerailed with a sling, the weight of the car is usually enough to crush and distort the jacket). I.e. http://www.railpictures.net/viewphoto.php?id=92612&nseq=134
Yes, some tankcars do employ electrical equipment to reheat a product that solidifies/congeals in the tank (i.e. sulfur, pitch, pine tar, maleic anhydride). There is a box that is connected to an electrical source an is located usually on the end of the car (like some CGTX pitch cars) or on top (like some UTLX cars). The location is usually a customer-specified option, based on their loading/unloading facilities. http://www.railcarphotos.com/PhotoDetails.php?PhotoID=18818
Hope this info is helpful,
Peter.
The only change that I would make to Peter’s message is that the Canadian source of sulphur is not the oil sands, but rather the Natural Gas wells in the eastern foothills of the Rocky Mountains which tap “Sour” gas. The natural gas as it comes out of the well contains large amounts of sulphur which must be stripped out before the gas is sold.
Thanks for all the replies. Word has it that the source of the sulfur (sulphur?) is Texas, not Canada. Any truth to that?
Well, if it’s sulfur it comes from Texas–if it’s sulphur it comes from Canada. Naturally, most of the stuff we see is sulphur. [;)]
Smells the same, though, I’ll bet!
Just a note to add to Peter’s accurate remarks: I’ve never seen sulfur transported in electrically heated cars (I think pitch or coal tar is the only commodity I’ve ever seen carried in those–think Koppers Company).
Large amounts of sulfur is a bit of an understatement, I’ve seen pictures of the blocks of sulfur at the gas fields in Alberta.
More like small landmasses.
I am assuming that most of the California produced sulfur must be trucked to ports since sulfur tankcars and hoppers are very rare out here.
Since it would cost considerably more to ship sulfur from Alberta to Florida than from Texas to Florida, I would suspect unless buyer could get the Alberta sulfur for considerably less, it probably comes from Texas.
The Canadians are practically giving it away, they can only store so much. The delivered cost in Florida is mostly the transportation bill.
Sulfur’s primary sources are sour gas, sour oil, and sulfide-ore smelting. Its primary end uses are phosphate fertilizer production, oil refining, oxide-ore leaching, rubber manufacture, and numerous intermediate chemical processes. In most uses sulfur is in the form of sulfuric acid. Sulfide ore smelting is a direct-to-acid recovery form, but for sour gas and sour oil it has the intermediate phase of elemental sulfur.
Sulfur is an unusual commodity in that its supply is forced into existence as a byproduct of valuable minerals production, and generally its supply locations are not well-associated with its consumption locations. In effect, most of the sulfur that is being transported is being driven by the need to dispose of excess, not demand. In California sulfur’s value is strongly negative as there is heavy production from California’s and Alaska’s heavy oil, no local demand, and receivers overseas are paying a delivered cost that is significantly less than the transportation cost it takes to deliver it. In Florida and South Carolina, where there is very little oil or gas production or refining, but an enormous production of phosphate ore for phosphoric acid fertilizer, sulfur has a positive value of about +$50/ton. The abundance of elemental sulfur production in the Rocky Mountain states, the Gulf Coast states, and the Canadian prairie provinces makes it impossible for California sulfur to leapfrog over these sources and supply the Florida and South Carolina market.
RWM
Do the Puget Sound refineries ship the sulfur out from local ports? I saw some bulk loading facilities in the satellite photographs but I did not see any sign of what types of commodities.
I have always wonder where the open top hopper I saw placarded for sulfur was coming from and going to.
For 2007 (latest comprehensive numbers):
Washington State produced 130,000 metric tons of elemental sulfur, and exported virtually all of it.
California, by comparison, produced 945,000 metric tons and exported 909,000 metric tons.
RWM
The amount of MS coming out of Canada via UP at Eastport, Idaho, has surged over the past few months, to the point where southbound manifests are looking more like unit tank trains. Especially so with the decline in imports of Canadian lumber due to the housing construction slump and falling US dollar. These trains are also carrying other southbound tank car loads, most notably anhydrous ammonia and propane. UP has run at least one unit MS train out of Eastport that I know of, back in November 2004, five units pulling 64 tank cars.
Just two things to add:
Beaulieu: thanks for correcting the info.
Carl: You are right, MS is not transported in tankcars with electric heating equipment (my previous post was misleading).
Peter.
Don’t forget Sulphur, Louisiana, where it was mined, using hot water–run hot water down into the well, and bring the sulphur and water mix up.
Johnny
Molten suflur trains ran from the refineries in Martinez, Crockett and Benicia east of San Francisco. I do not know if they still run them. Can someone in the area tell us if they still do?
When I go up there, I see many LPG tankcars but no sulfur tankcars. The same is true for the LA and Bakersfield areas. It is also very rare to see a sulfur tankcar come through the San Joaquin Valley.
The only refinery at Crockett is a sugar refinery. The current locations are Richmond, Rodeo, Martinez, Avon, and Benicia. There used to be one at Hercules.