ISO Tank Containers Replace Drums As Specialty Chemical Storage Vessels
Jul 1, 1998 12:00 PM
ISO tank containers serve as storage as well as transportation vessels for Baker Petrolite, Houston, Texas. The specialty chemical supplier uses tank containers in some applications rather than 55-gallon drums, said Bill Beier, manager of resource operations for Baker Petrolite.
Speaking at the International Intermodal Expo held May 6-8 in Dallas, Texas, Beier said that IMO-1 tank containers built for hazardous chemicals are much safer than drums because of rigid Department of Transportation (DOT) manufacturing and testing regulations. They also are more economical and environmentally friendly.
"Our customer requirements focus on these three key requirements for the handling of any dangerous or hazardous chemical," Beier said. "The intermodal tank meets all these requirements beautifully."
Baker Petrolite supplies specialty chemicals to the oil production industry, the onshore and offshore oil patch, refineries, hydrocarbon processing plants, and power generation facilities.
Beier defined a specialty chemical as a highly technical, formulated - and often patented - additive. Specialty chemicals are used by customers to solve a problem or prevent a problem.
"Specialty chemicals historically have been a drum business," Beier said. "When you look at it from the perspective of a company that is using a small amount of chemical in various locations in the plant, you really can't get away from 55-gallon drums. But the applications for which we use ISO tank containers are quite different."
Beier listed two types of chemicals supplied by Baker Petrolite using tank containers instead of drums: biocides/ herbicides and additives for improving the flow of crude oil in pipelines.
Baker Petrolite pipeline products are used to process hydrocarbon streams, Beier said. Thus, the company's specialty chemicals must have a hydrocarbon base. They are very flammable or at least combustible.
The product formulation includes mediums such as water or kerosene, to which are added other elements, he said.
Additives for improving the flow of oil in pipelines can become very viscous, Beier said. At low temperatures, this quality can be a problem with transportation and storage. For example, if a cup of one of these highly viscous products were turned upside down at room temperature, the product would not flow out.
On the other hand, the biocides and herbicides are toxic. They are meant to kill microorganisms in a cooling tower, or to kill weeds in an irrigation canal, Beier said. If used improperly, these products can kill a person.
"The specialty formulations we supply prevent a problem for our customers, but they often are problem fluids in terms of handling," he said. "They may be very corrosive to steel and detrimental to plastics and elastomers."
To safely transport chemicals to customers and raw materials to company manufacturing plants, Baker Petrolite has a fleet of 500 IMO-1 containers and 150 chassis. The tank containers have capacities ranging from 1,200 to 6,300 gallons. The company owns only 5% of its transportation equipment and the rest is leased.
Baker Petrolite requires tank containers with the ability to handle pressure offloading with pressures ranging from 16 to 60 psig, he said. Viscous liquids are forced out of the tanks at customer locations with nitrogen pressure. The tanks are well suited to the special characteristics of the chemicals, and they help the company meet customer requirements for safety and economy.
The simplest use of transportation equipment operated by Baker Petrolite is delivering chemicals to a storage facility on a customer site, Beier said. Product is picked up at a Baker Petrolite manufacturing plant. Then it travels over the road or over the ocean before it is delivered to storage.
Many times, though, because of the nature of the product or the nature of the customer site, no storage is available, he added. In that case, the tank container makes a perfect temporary storage vessel, reducing the requirement of the customer to invest in fixed storage.
In some instances, the tank container becomes a feed tank, supplying product on site at a customer location for the duration of use of the chemical, Beier said.
"A pipeline flow improver is injected into a crude oil pipeline to increase the through-flow," he said. "It will improve flow through the pipeline from 40% to 50%. But you have to treat the crude oil all along the pipeline. Thus, the application is continuous injection at many points along the pipeline. We have pipelines all over the world that we treat with our improver product."
In this typical application, the tank container is placed on site at the pipeline. It becomes a temporary storage vessel and feed tank in addition to a transportation vessel. The tank feeds into a sophisticated system of pumps used to get the product into the pipeline.
"IMO-1 tanks are readily available," Beier said. "Since we lease 95% of our fleet, we can acquire more chassis and tanks when we need them through a leasing firm. When I need 10 more tanks because we've got a new application on a pipeline, I call the leasing company and they will be delivered the next day."
Baker Petrolite uses DOT51 tank containers for transportation of herbicides.
"This product is very dangerous if misused," Beier said. "It is flammable, toxic, and corrosive to materials. This is a product that is not made in the United States. The raw materials for this product are shipped in large bulk containers from Europe and Asia. Because of toxicity, we try to minimize the use of over-the-road transportation."
The materials are transported by rail-ocean-rail to the company distribution plant where they are broken down into smaller, usable container sizes for the market, he said.
Because of their size, ISO/IMO tanks provide an economic advantage over 55-gallon drums or intermediate bulk containers (IBCs).
"Tank containers can move large quantities in a single vessel, reducing the minimum price per pound that we have to put into our cost basis," Beier said. "This provides better economics or better profitability, depending on the market."
Tank containers also are safer because they require less product handling than drums and IBCs. One 5,500-gallon ISO tank replaces 100 of the 55-gallon drums. Less product handling also results in savings for the company.
"From the safety standpoint, these tanks are regulated, and they are built for hazardous duty," he said. "On the environmental issue, containers reduce emissions because dangerous products can be carried under pressure."
Tank containers designed to transport dangerous goods are constantly examined and tested to ensure they are safe, said Paul Sireci, consultant-tank services, Unicon International, San Francisco, California.
Container manufacturers must ensure that equipment is built according to code requirements. Thus, suppliers have established quality assurance inspection programs that cover all stages of production, beginning with container design.
"To ensure that safety requirements are met, manufacturers have quality assurance manuals establishing the requirements of pressure vessel codes," Sireci said. "Suppliers follow a rigorous protocol. Procedures are set for welding specifications and various nonstructural tests such as X-ray and ultrasound."
Two prototype tests are very important in ensuring safety, he said. One is a rail impact test. A tank is placed on a rail car and subjected to tremendous force, about five times the maximum gross weight of the container. The second is a hydrostatic test. It determines whether tanks hold up to design pressure when filled with water and pressured up to the original design pressure.
"Quality control extends beyond the manufacture of hazardous class tanks," he said. "By code, these tanks must be pressure tested at 21Ž2- and 5-year intervals to ensure that they are sound."
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