Tank Trucks and Cars

This chapter is not concerned with accidents on the road. Rather, it describes some of the many incidents that have occurred while tank trucks and cars (known in Europe as road and rail tankers) were being filled or emptied. Section 18.8 shows how hazard and operability studies have been used to spot potential hazards in filling systems, and Section 22.3 describes some runaway reactions in tank trucks and cars.. 

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Tank trucks and cars have been overfilled on many occasions, both when filled automatically and when filled by hand. 

Tank trucks and cars that are filled by hand have been overfilled because the filler left the job for a few minutes and returned too late. On one occasion an operator thought a tank truck had a single-compartment tank when in fact there were two compartments. He tried to put the full load into one compartment. 

Compressed air is often used to empty tank trucks and cars. Plastic pellets are often blown out of tank trucks. When the tank is empty, the driver vents the tank and then looks through the manhole to check that the tank is empty. One day a driver who was not regularly employed on this job started to open the manhole before releasing the pressure. When he had opened two out of five quick-release fastenings, the manhole blew open. The driver was blown off the tank top and killed. 

Rail cars, tank trucks, and some reactors and storage tanks were cleaned manually by personnel who entered the vessel fatalities occurred from unexpected or undetected low oxygen content or toxicity. An inherently safer system is a rotating pressurized water spray head that does the cleaning without vessel entry. 

Commercial grades Available in three grades refinery (50-70%), chemical (90-92%), and polymer (99%) grade. The remaining percentage in each case is mainly propane. It is shipped as a liquid in pipelines, tank cars, tank trucks, and steel cylinders. Storage is as a liquid at pressures of about 200 psi. 

Commercial grades Available in three grades refined-535, refined-485 (nitration grade), and industrial. The numbers following the grade refer to the freezing point specification times 100. It is shipped in steel drums, tank trucks, and tank cars under heavily regulated conditions. 

Sale grades of methanol include 95 and 97% purity. U.S. Federal grade must meet 99.8% minimum purity and be acetone-free. Methanol can be transported in conventional tank trucks, rail cars, ships, and barges, but it must be in closed systems. The red hazardous materials markings are required. 

The alcohols are available in drums and via tank trucks and rail tank cars. The bulk shipments of the heavier higher alcohols need to be in equipment with heating coils since, as you can see in Table 15—3, the melting points are above ambient temperature conditions. ... 

Properties and handling. MIBK is a colorless liquid and has a pleasant, almost fruity, odor. Unlike acetone and MEK, it is only slightly soluble in water. That happens to solvents as the size of the molecule gets larger. Most of the commercial trade in MIBK is in the technical grade (98.5%). Bulk shipments can be handled in conventional tank trucks and tank cars, but the hazardous material markings must be displayed. 

Properties and handling. MMA is a colorless, sweet smelling, volatile liquid that boils at 212° . MMA readily polymerizes with itself, and usually has trace amounts of hydroquinone added as an inhibitor. MMA is traded as technical grade and is shipped in lined tank cars, tank trucks, and drums. The hazardous material warnings are required on all shipments.. 

Shipment and. Storage, Sulfur monochloride is minimally corrosive to carbon steel and iron when dry. If it is necessary to avoid discoloration caused by iron sulfide formation or chloride stress cracking, 310 stainless steel should be used. Sulfur monochloride is shipped in tank cars, tank trucks, and steel drums. When wet, it behaves like hydrochloric acid and attacks steel, cast iron, aluminum, stainless steels, copper and copper alloys, and many nickel-based materials. Alloys of 62 Ni—28 Mo and 54 Ni—15 Cr—16 Mo are useful under these conditions. Under DOT HM-181 sulfur monochloride is classified as a Poison Inhalation Hazard (PIH) Zone B, as well as a Corrosive Material (DOT Hazard Class B). Shipment information is available (140). Uses, The reaction of S-CL with aromatic compounds can yield disulfides or mixtures of mono-, di-, and polysulfides. 

Transportation of Chemicals. Feed materials and finished products are frequently transported by tank truck and railroad tank cars. Design, construction, and movement of these vehicles is regulated by the U.S. Department of Transportation (DOT) (97). The DOT regulations require placarding of material-transport vehicles to alert the public and emergency personnel to the nature of their contents. 

Molten maleic anhydride is shipped in tank rail cars, tank trucks and isotanks (for overseas shipments). Solid form maleic anhydride is produced from molten maleic anhydride as briquettes or pastille weighing 0.5 to 20 g. Fumaric acid is shipped in solid form, the particles size varying based upon the specification. 

Nameplate capacities of naphthenic acid producers in North America are 9000 metric tons of crude and refined acid at Meridiem (Tuscaloosa, Ala.), and 3600 t of crude acid at Hewchem (Gulfport. Miss.). However, actual production capacity may vary widely as a result of the mix of feedstocks being processed. Naphthenic acid products are shipped in tank cars, tank trucks, and drums under DOT 9137/UN 3082 identifications numbers. 

Furan, a Class 3 DOT hazard, is shipped in tank cars, tank trucks and in heavy duty drums. The selling price of furan in bulk is listed at 1.60/lb. 

Tank trucks and rail cars that contain nitric acid below 70% concentration must be made of special steel that is resistant to nitric acid. Suitable materials include97 304L Stainless Steel (DIN/EN 1.4306 = UNS S 30403), 321 Stainless Steel (DIN/EN 1.4541 = UNS S 32100), 347 Stainless Steel (DIN/EN 1.4550 = UNS S 34700), (DIN/EN 1.4465 = UNS S 31050), and Antinite (DIN/EN 1.4361 = UNS S 30601) - Recommended for concentrations above 85%. 

This was a PVC plant located in an industrial area that had operated for about nine years. Vinyl chloride, a very flammable compressed gas, was received on the site by rail cars and tank trucks and stored in seven large bullet tanks. Five of the bullet tanks were 10 ft. in diameter and 100 ft. long. They were spaced about 10 ft. apart. The two smaller tanks were about two-thirds the volume of size of the others. 

Polyacrylamide powders are typically shipped in moisture-resistant bags or fiber packs. Emulsion and solution polymers are sold in drums, tote bins, tank trucks, and tank cars. The transportation of dry and solution products is not regulated in the United States by7 the Department of Transportation, but emulsions require a DOT NA 1693 label. 

Air Point source emission stack, vent (e.g., laboratory hood, distillation unit, reactor, storage tank vent), material loading/unloading operations (including rail cars, tank trucks, and marine vessels). Fugitive emissions pumps, valves, flanges, sample coUection, mechanical seals, relief devices, tanks. Secondary emissions waste and wastewater treatment units, cooling tower, process sewer, sump, spill or leak areas. Equipment wash solvent or water, lab samples. 

The 50% aqueous acrylamide is the preferred form because it eliminates the handling of solids and because its cost is lower. This is a result of the new manufacturing method put into effect in 1971. The aqueous form is applicable to nearly all the end uses of acrylamide when volume is taken into account. Aqueous acrylamide is shipped in tank trucks, rail cars, or dmms, but small samples can also be obtained. The solution should be kept in stainless steel or in tanks coated with plastic resin (phenolic, epoxy, or polypropylene). All containers, including tank trucks and rail cars, must be rinsed prior to disposal or return. When shipping costs are an important consideration, solid acrylamide may be the desired form. Acrylamide should be stored in a well ventilated area away from sunlight. The temperature should be under 30°C, and under these conditions no change of quality should be noticed for at least 3 months. Typical specifications for the 50% aqueous solution are shown in Table 5 and for the solid monomer in Table 6. 

Liquid hydrogen sulfide has been classified as a flammable compressed gas for shipment in both tank trucks and tank cars by governmental authorities both in the United States and Canada. Department of Transportation special permits authorize use of type 105A-600W tank cars filled to a maximum density of 68%. With a capacity of 13,500 gal, these insulated tank cars will hold about 30 short tons net weight of liquid hydrogen sulfide. 

NaHS, marketed as 71.5—74.5 wt % flakes and 43—60 wt % liquor in the high purity grades, is also available as 10—40 wt % liquor from the oil refining desulfurization process. NaHS is sold commercially in 22.7-kg bags, 181.4-kg drums, in tank trucks, and in rail cars. 

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