I saw. Semi truck hauling liquified CO2 yesterday. It was owned by POET Energ, a big player in the ethanol industry. That made me curious be there's a big fight going on over a proposed CO2 pipeline in our area. So I went down the rabbit hole to learn about liquified CO2.
The pipeline would go from ethanol plants on the plains to a home in the North Dakota oil fields. Hmmm.. If it can move by truck, is any of it moving by train? Every ethanol plant has a rail siding, as do a lot of big energy operations. Could liqu CO2 move profitably by rail?
Thanks to Chris / CopCarSS for my avatar.
I'd opine that the problem isn't moving the commodity by rail as such - the technology exists.
The problem is whether there are enough capable cars in existence, and if it's worth the expense to build such a fleet.
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...
ADM out of Cedar Rapids used to ship out CO2 by rail. I can't say that I've seen as much lately, but it might not be going my way.
Jeff
jeffhergertADM out of Cedar Rapids used to ship out CO2 by rail. I can't say that I've seen as much lately, but it might not be going my way. Jeff
I don't know about CO2.
I remember in 1967 when I was working at Etna, PA seeing a number of Linde insulate cars that were carrying Liquid Oxygen to the Pittsburgh steel mills for their 'basic oxygen furnaces'. The cars appeared to be 'box cars' but the box was the insulation around the tank holding the Liquit Oxygen - there was vent on the cars to keep the tanks from getting over pressured.
Never too old to have a happy childhood!
Murphy SidingCould liqu CO2 move profitably by rail?
We have a customer that gets a couple CO2 tanks a week.
big white cars with venting valves. Public usually calls them in to 911 once a year or so about a "tank car leaking".
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
Well, new CO2 pipelines seem to be about as popular as new oil and gas pipelines. If nothing else, maybe the ethanol plants can propose sending the CO2 by rail until people start screaming that it would be safer by pipeline.
jeffhergert ADM out of Cedar Rapids used to ship out CO2 by rail. I can't say that I've seen as much lately, but it might not be going my way. Jeff
zugmann Murphy Siding Could liqu CO2 move profitably by rail? We have a customer that gets a couple CO2 tanks a week. big white cars with venting valves. Public usually calls them in to 911 once a year or so about a "tank car leaking".
Murphy Siding Could liqu CO2 move profitably by rail?
Universal Industrial Gases, Inc...CO2 Carbon Dioxide Properties, Uses, Applications - Recovery from Industrial Sources - Concentration in Air (uigi.com)
Scroll down for it's uses.
Murphy Siding jeffhergert ADM out of Cedar Rapids used to ship out CO2 by rail. I can't say that I've seen as much lately, but it might not be going my way. Jeff is that from an ethanol plant?
is that from an ethanol plant?
Not sure what they're producing in Cedar Rapids, but it sure stinks when the wind is coming from the wrong direction. Their website lists a whole range of products- ethanol is just one. We're good friends with a couple who used to live here and he worked for them as a chemical engineer, but he quit and they moved to South Carolina.
Brian (IA) http://blhanel.rrpicturearchives.net.
CO2 and Nitrogen combined are used to pump draft beer in bars. And in soda fountains.
jeffhergert Universal Industrial Gases, Inc...CO2 Carbon Dioxide Properties, Uses, Applications - Recovery from Industrial Sources - Concentration in Air (uigi.com) Scroll down for it's uses. Jeff
azrail CO2 and Nitrogen combined are used to pump draft beer in bars. And in soda fountains.
Murphy,
Yes, Carbon Dioxide, Liquefied is now and has been for decades a tank car commodity.
Mac McCulloch
Murphy SidingI'm curious what kind of industry brings in CO2? With everyone trying to get rid of it, i should be cheap.
One of the CO2 pipeline projects in ND goes to the oil fields for enhanced recovery. While you would think it is cheap, the seller will charge as much as the buyer will pay.
One side effect of shipping CO2 is that at times the safety valve will let the gas escape creating a small white plume at the top. When this happens many times some unknowing bystander along the line will see this plume and think it is something bad happening. So they call the operations/dispatcher's center, who in turn contacts the train crew to have them stop and check the train. Sometimes stopping can be averted if the person has taken the time to get a car number which the crew can then check on their hazardous print out to see that is in fact CO2 and it isn't going to hurt anyone.
.
BigJimOne side effect of shipping CO2 is that at times the safety valve will let the gas escape creating a small white plume at the top. When this happens many times some unknowing bystander along the line will see this plume and think it is something bad happening. So they call the operations/dispatcher's center, who in turn contacts the train crew to have them stop and check the train. Sometimes stopping can be averted if the person has taken the time to get a car number which the crew can then check on their hazardous print out to see that is in fact CO2 and it isn't going to hurt anyone.
That happens when any liquified gasses are shipped - CO2, O2, N, etc. Since they all develop pressures that must be vented to prevent a pressure caused explosion.
Watched many of these cars on trains on the P&W Sub out of Pittsburgh during my stint of working Operator position during the Summer of 1967 -
Thanks for the picture. After scanning a 1977 copy of the Railroad Equipment Register, I would often wonder just what Class XT cars looked like.
All,
We have two almost true, but misleading, posts above.
Jim's story is correct. His language is not. Carbon Dioxide tank cars have a 'pressure regulating valve' in addtion the their safety valve. Pressure regulating valves, which are rare, start to discharge at a pressure well below the start to discharge pressure of the safety valve. I havent been a Bureau of Explosives Inspector for decades by my memory is that cars were Specifiction 105A500W, the 500 being tank test pressure. That implies a safety valve start to discharge pressure of 375 pounds. I do not recall what the pressure regulating valve start to discharge pressure was/is, but was below 375 pounds.
Balt's statement that discharges of ALL liquefied gasses are routine in transportation is false. The name of the game is to keep the juice in the can. It is true that a few cryogenic commodities, and his list is of crogenic commodities, have pressure regulating valves. These are low pressure, 60 or 100 pound tank test pressure, cars. They have safety valves that start to discharge at 75% of tank test pressure, and they have pressure regulating valves that start to discharge at a lower pressure, I think it is 25 pounds.
I lived this for 13 years as a Bureau of Explosives Inspector, Manager Field operations, and Superintendent Hazardous Material Control for Southern Pacific. If you want to check me out see 49 CFR, parts 100 through 199. Tank car part is 174 IIRC. If you are not already familiar with how the Hazardous Material Regulations are structured, you have many hours of unhappy reading ahead of you!
PNWRMNMAll, We have two almost true, but misleading, posts above. Jim's story is correct. His language is not. Carbon Dioxide tank cars have a 'pressure regulating valve' in addtion the their safety valve. Pressure regulating valves, which are rare, start to discharge at a pressure well below the start to discharge pressure of the safety valve. I havent been a Bureau of Explosives Inspector for decades by my memory is that cars were Specifiction 105A500W, the 500 being tank test pressure. That implies a safety valve start to discharge pressure of 375 pounds. I do not recall what the pressure regulating valve start to discharge pressure was/is, but was below 375 pounds. Balt's statement that discharges of ALL liquefied gasses are routine in transportation is false. The name of the game is to keep the juice in the can. It is true that a few cryogenic commodities, and his list is of crogenic commodities, have pressure regulating valves. These are low pressure, 60 or 100 pound tank test pressure, cars. They have safety valves that start to discharge at 75% of tank test pressure, and they have pressure regulating valves that start to discharge at a lower pressure, I think it is 25 pounds. I lived this for 13 years as a Bureau of Explosives Inspector, Manager Field operations, and Superintendent Hazardous Material Control for Southern Pacific. If you want to check me out see 49 CFR, parts 100 through 199. Tank car part is 174 IIRC. If you are not already familiar with how the Hazardous Material Regulations are structured, you have many hours of unhappy reading ahead of you! Mac McCulloch
Liquified gases can, for a variety of reasons, generate pressures in their containers that require venting of said over pressure conditions. Yes, the name of the game is to get as much of the product as possible from origin to destination. Venting does happen when pressures activate the safety relieve valves.
I have seen such cars venting when they passed my position. Are they venting all the time, no! But they do vent from time to time.
I'm more into methane production, myself!
[quote user="BaltACD"]Liquified gases can, for a variety of reasons, generate pressures in their containers that require venting of said over pressure conditions. Yes, the name of the game is to get as much of the product as possible from origin to destination. Venting does happen when pressures activate the safety relieve valves. I have seen such cars venting when they passed my position. Are they venting all the time, no! But they do vent from time to time.
Balt,
You are confusing the exception with the rule.
The basic rule is that safety valves must be set to start to discharge at a pressure higher than the pressure that will ever obtain in normal transportation. Think chlorine, Vinyl Chloride Monomer, and about a thousand others.
Very, very few tank car commodities have the pressure regulating valves you are describing. This concept is a very big deal, and because of your experience, I suspect most readers take your statements as gospel and you are right at least 99% of the time. This is just not one of those times.
Safety valves and pressure regulating valves are very different things.
Mac
PNWRMNMBaltACDLiquified gases can, for a variety of reasons, generate pressures in their containers that require venting of said over pressure conditions. Yes, the name of the game is to get as much of the product as possible from origin to destination. Venting does happen when pressures activate the safety relieve valves. I have seen such cars venting when they passed my position. Are they venting all the time, no! But they do vent from time to time. Balt, You are confusing the exception with the rule. The basic rule is that safety valves must be set to start to discharge at a pressure higher than the pressure that will ever obtain in normal transportation. Think chlorine, Vinyl Chloride Monomer, and about a thousand others. Very, very few tank car commodities have the pressure regulating valves you are describing. This concept is a very big deal, and because of your experience, I suspect most readers take your statements as gospel and you are right at least 99% of the time. This is just not one of those times. Safety valves and pressure regulating valves are very different things. Mac
BaltACDLiquified gases can, for a variety of reasons, generate pressures in their containers that require venting of said over pressure conditions. Yes, the name of the game is to get as much of the product as possible from origin to destination. Venting does happen when pressures activate the safety relieve valves. I have seen such cars venting when they passed my position. Are they venting all the time, no! But they do vent from time to time. Balt, You are confusing the exception with the rule. The basic rule is that safety valves must be set to start to discharge at a pressure higher than the pressure that will ever obtain in normal transportation. Think chlorine, Vinyl Chloride Monomer, and about a thousand others. Very, very few tank car commodities have the pressure regulating valves you are describing. This concept is a very big deal, and because of your experience, I suspect most readers take your statements as gospel and you are right at least 99% of the time. This is just not one of those times. Safety valves and pressure regulating valves are very different things. Mac
All I know I have viewed transportation vehicles of liquified gases vent to atmosphere. Primarly rail cars as I watched trains pass for years when I held Operators positions at about 50 locations on various divisions of the B&O, however, I have also seen it from trucks. What the reason for the venting is I'll leave to the experts in the movement of liquified gases.
PNWRMNMAll, We have two almost true, but misleading, posts above. Jim's story is correct. His language is not. Carbon Dioxide tank cars have a 'pressure regulating valve' in addtion the their safety valve. Pressure regulating valves, which are rare, start to discharge at a pressure well below the start to discharge pressure of the safety valve.
Jim,
You witnessed the pressure regulating valve discharging, not the safety valve as you claimed. They are NOT the same thing.
https://www.govinfo.gov/content/pkg/CFR-2017-title49-vol3/xml/CFR-2017-title49-vol3-part179.xml
§ 179.15
Pressure relief devices.Except for DOT Class 106, 107, 110, and 113 tank cars, tanks must have a pressure relief device, made of material compatible with the lading, that conforms to the following requirements:(a) Performance standard. Each tank must have a pressure relief device, made of materials compatible with the lading, having sufficient flow capacity to prevent pressure build-up in the tank to no more than the flow rating pressure of the pressure relief device in fire conditions as defined in appendix A of the AAR Specifications for Tank Cars (IBR, see § 171.7 of this subchapter).(b) Settings for reclosing pressure relief devices. (1) Except as provided in paragraph (b)(2) of this section, a reclosing pressure relief valve must have a minimum start-to-discharge pressure equal to the sum of the static head and gas padding pressure and the lading vapor pressure at the following reference temperatures:(i) 46 °C (115 °F) for noninsulated tanks;(ii) 43 °C (110 °F) for tanks having a thermal protection system incorporating a metal jacket that provides an overall thermal conductance at 15.5 °C (60 °F) of no more than 10.22 kilojoules per hour per square meter per degree Celsius (0.5 Btu per hour/per square foot/per degree F) temperature differential; and(iii) 41 °C (105 °F) for insulated tanks.(2)(i) The start-to-discharge pressure of a pressure relief device may not be lower than 5.17 Bar (75 psig) or exceed 33 percent of the minimum tank burst pressure.(ii) Tanks built prior to October 1, 1997 having a minimum tank burst pressure of 34.47 Bar (500 psig) or less may be equipped with a reclosing pressure relief valve having a start-to-discharge pressure of not less than 14.5 percent of the minimum tank burst pressure but no more than 33 percent of the minimum tank burst pressure.(3) The vapor tight pressure of a reclosing pressure relief valve must be at least 80 percent of the start-to-discharge pressure.(4) The flow rating pressure must be 110 percent of the start-to-discharge pressure for tanks having a minimum tank burst pressure greater than 34.47 Bar (500 psig) and from 110 percent to 130 percent for tanks having a minimum tank burst pressure less than or equal to 34.47 Bar (500 psig).(5) The tolerance for a reclosing pressure relief valve is ±3 psi for valves with a start-to-discharge pressure of 6.89 Bar (100 psig) or less and ±3 percent for valves with a start-to-discharge pressure greater than 6.89 Bar (100 psig).(c) Flow capacity of pressure relief devices. The total flow capacity of each reclosing and nonreclosing pressure relief device must conform to appendix A of the AAR Specifications for Tank Cars.(d) Flow capacity tests. The manufacturer of any reclosing or nonreclosing pressure relief device must design and test the device in accordance with appendix A of the AAR Specifications for Tank Cars.(e) Combination pressure relief systems. A non-reclosing pressure relief device may be used in series with a reclosing pressure relief valve. The pressure relief valve must be located outboard of the non-reclosing pressure relief device.(1) When a breaking pin device is used in combination with a reclosing pressure relief valve, the breaking pin must be designed to fail at the start-to-discharge pressure specified in paragraph (b) of this section, and the reclosing pressure relief valve must be designed to discharge at not greater than 95 percent of the start-to-discharge pressure.(2) When a rupture disc is used in combination with a reclosing pressure relief valve, the rupture disc must be designed to burst at the pressure specified in paragraph (b) of this section, and the reclosing pressure relief valve must be designed to discharge at not greater than 95 percent of the pressure. A device must be installed to detect any accumulation of pressure between the rupture disc and the reclosing pressure relief valve. The detection device must be a needle valve, trycock, or tell-tale indicator. The detection device must be closed during transportation.(3) The vapor tight pressure and the start-to-discharge tolerance is based on the discharge setting of the reclosing pressure relief device.(f) Nonreclosing pressure relief device. In addition to paragraphs (a), (b)(4), (c), and (d) of this section, a nonreclosing pressure relief device must conform to the following requirements:(1) A non-reclosing pressure relief device must incorporate a rupture disc designed to burst at a pressure equal to the greater of 100% of the tank test pressure, or 33% of the tank burst pressure.(2) The approach channel and the discharge channel may not reduce the required minimum flow capacity of the pressure relief device.(3) The non-reclosing pressure relief device must be designed to prevent interchange with other fittings installed on the tank car, must have a structure that encloses and clamps the rupture disc in position (preventing any distortion or damage to the rupture disc when properly applied), and must have a cover, with suitable means of preventing misplacement, designed to direct any discharge of the lading downward.(4) The non-reclosing pressure relief device must be closed with a rupture disc that is compatible with the lading and manufactured in accordance with Appendix A of the AAR Specifications for Tank Cars. The tolerance for a rupture disc is + 0 to −15 percent of the burst pressure marked on the disc.(g) Location of relief devices. Each pressure relief device must communicate with the vapor space above the lading as near as practicable on the longitudinal center line and center of the tank.(h) Marking of pressure relief devices. Each pressure relief device and rupture disc must be permanently marked in accordance with the appendix A of the AAR Specifications for Tank Cars.[Amdt. 179-52, 61 FR 28678, June 5, 1996, as amended by Amdt. 179-52, 61 FR 50255, Sept. 25, 1996; 62 FR 51561, Oct. 1, 1997; 64 FR 51919, Sept. 27, 1999; 66 FR 45390, Aug. 28, 2001; 68 FR 75759, Dec. 31, 2003]
Trust me when a safety valve is going off on a non pressure rated tank it means someone done screwed up big time. Around here the tanks are rated for a maximum pressure of around 40 psi and that's mostly so we can push the product out of the trailer.
Now cryogenic tanks are a whole different animal. They have both pressure relief valves and a venting valve in their design. I'm talking about LN2 and LCO2 tanks as well as most other cryogenic liquid tanks. The reason for why these have both is simply this. If the venting valve freezes and it can happen in humid or raining conditions the pressure relief valve can still keep the pressure from causing a rupture. The problem with hauling cryogenic tanks is that it's always trying to get back above it's boiling point and since most of them a way below -300 degrees it really doesn't take much to get it going.
Now pressurized gas such as propane and others only have pressure relief valves. Those are not the tanks you ever want to have a leak on.
Some Q's about the boxcars tank details...
how big (meaning, measurement not gallons); horizontal or vertical?; how were they loaded/unloaded? internal piping?
This is all very mysterious...
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