PROPYLENE oxide (PO) demand has remained strong during this tough economy for one US chemical company. At times, however, the company has struggled with transportation capacity and efficiency issues.
Managers at the company — Huntsman International LLC — launched a concerted effort in January to address the transportation issues. The solution — developed over a nine-month period — brought a complete reorganization of the propylene oxide hauling operation that is directed from Huntsman's administrative headquarters in The Woodlands, Texas.
“We produce propylene oxide as an internal feedstock for our chemical plants in the Gulf Region, and we're scrambling to meet their demand,” says Josh A Nordgulen, Huntsman manager for truck transportation and logistics. “Shipment delays can be very costly. It is important that we move that product as efficiently, cost-effectively, and safely as possible.
“We had absolutely no consistency in our propylene oxide transportation operation. Many of our carrier partners were using owner-operators with relatively heavy sleeper tractors, and there was wide variation in tank trailers. In one areaof our operation, ISO tank containers were being used. We weren't able to haul maximum loads with anyof the equipment.”
High volume
That was a big problem, because Huntsman ships 230 million to 250 million pounds of propylene oxide a year to its other chemical plants in the Gulf Coast region. The smaller the load, the more shipments that are required to keep up with demand. This raises transportation costs and increases the risk of an accident.
“We felt it was critical to completely redesign Huntsman's logistics system for this product,” Nordgulen says. “We wanted to approach the propylene oxide transport activity from a new perspective.”
Huntsman logistics managers conducted a detailed review of the process from January through May. All of the Huntsman propylene oxide shipments are inter-plant movements, and the chemical is used primarily to make polyurethane foam materials, glycols, and amines for use in the automotive, construction, consumer, and other sectors.
Huntsman produces propylene oxide at their plant in Port Neches, Texas. Another Houston, Texas-area chemical company serves as a back-up supplier of propylene oxide to Huntsman. The chemical is hauled to Huntsman plants in Conroe and Dayton, Texas, and Geismer, Louisiana. The Conroe and Geismer plants each receive at least eight loads a day.
Following the review, Huntsman's logistics department issued a bid request to the seven core carriers under contract at the time to transport propylene oxide. Huntsman logistics officials outlined changes they wanted to make, including the use of standardized tractors and trailers, increased cargo capacity, a higher level of safety, dedicated drivers, and a five-year contract.
During the bid process, Huntsman logistics officials held individual carrier meetings to discuss issues related to the operational changes that were requested. When the bids came in, there was a 33% difference between the high and low.
“In the meetings and through that initial bid process, we heard a lot of ideas on how each carrier would address our requirements,” Nordgulen says. “We heard some good ideas, but they weren't quite what we wanted. However, we were able to trim the carrier group to four and request a second round of bids.”
Slay Transportation Co Inc, St Louis, Missouri, turned in the winning bid and was named to handle all of Huntsman's interplant propylene oxide shipments in the Gulf Coast region. While not previously one of Huntsman's propylene oxide carriers, Slay Transportation showed a clear understanding of what the Huntsman logistics team wanted to accomplish.
“Slay Transportation turned in what was clearly the best bid and presentation in the second round,” Nordgulen says. “We've worked with them on other chemical hauls and know that they are a very capable tank truck carrier with the ability to provide a wide range of services. We expect our partnership with Slay Transportation to grow in other areas.”
Plant involvement
Slay Transportation agreed to direct involvement in Huntsman's logistics operations at the plant level and the administrative headquarters in The Woodlands. In addition, discussions during and after the bid process brought clear agreement on the vehicle specifications needed for improved productivity and safety.
Tractor and trailer specifications were finalized during meetings that included vehicle manufacturer representatives and Huntsman plant personnel. “We brought in all of the key players for these meetings, and we quickly reached consensus on equipment design and the way the vehicles would be operated,” Nordgulen says. “This project moved forward very fast.”
Slay Transportation placed orders in June for 10 tractors and 15 tank trailers for the propylene oxide operation. Tare weight was a major consideration.
“This vehicle order was based on shipment volumes projected during the bid process, but the volumes are increasing and we probably will need more tractors,” says Gary Slay, president of Slay Transportation. “It's a good problem to have.
“These rigs were specified to handle a maximum payload of 56,000 pounds, which we can haul in Texas with overweight permits. We're limited to 53,500-lb payloads in Louisiana.”
Nordgulen adds that payloads prior to the propylene oxide transport reorganization never exceeded 44,000 pounds. “We'll be able to cut 861 shipments annually with the new tractors and trailers that Slay Transportation is operating,” he says. “We can load the new trailers to 95% of tank capacity, compared with 90% for the trailers used previously.”
Tractor specs
On the tractor side, Slay Transportation chose daycab Freightliner Cascadias with a 14,028-pound tare weight. The drivetrain includes a Detroit Diesel DD13 engine rated for 450 horsepower at 1,800 rpm and a 10-speed Eaton Fuller transmission.
Lower tractor tare weight was made possible with Meritor Steelite brake drums (60-lb savings), Holland FW35AL aluminum fifthwheel (60-lb savings), Alcoa aluminum wheels, Michelin XDA1 widebase drive tires, single 120-gallon fuel tank, and horizontal exhaust. Leaving out the passenger seat shaved another 40 pounds.
Safety got plenty of attention in the spec'ing process. In addition to Meritor WABCO roll stability, the tractors were ordered with Meritor WABCO's OnGuard collision safety system. OnGuard is a forward-looking, radar-based adaptive cruise control system with active braking.
“OnGuard is becoming increasing popular with fleets, and it was specified on about 40% of the trucks we sold this year,” says Joe Switzer, sales representative for Truck Centers Inc, the St Louis truck dealer that sold the new tractors to Slay Transportation. “OnGuard activates the vehicle brakes anytime the tractor is within 3.6 seconds of impacting another object.”
While standard DOT407 and MC331 tank trailers were used previously, Slay Transportation and the Huntsman logistics team worked with Polar Tank Trailer LLC to determine that a hybrid DOT407 trailer was needed to address the safety and operational needs at the Huntsman plants and the third-party loading facility. The result was an 8,500-gallon stainless steel tank trailer with an 11,000 tare weight.
“This is a mission-specific DOT407 trailer that will be a perfect fit for Huntsman's propylene oxide operation,” says Randy Arlt, Polar Tank Trailer president. “Our biggest challenge with this project was blending productivity and durability, and we are confident we achieved that objective. This trailer increases payload capacity without compromising safety in any way.”
35 psi tanks
Polar's engineering team designed the uninsulated tanks with a 10-gauge shell and eight-gauge heads. “These tanks can easily handle the 35 psi maximum pressure allowed for DOT407 cargo tanks,” says Rick Connelly, Polar's vice-president of quality and engineering. “We need that because propylene oxide has a relatively high vapor pressure.”
The trailers were configured for dedicated propylene oxide service with closed-loop loading and unloading. The Polar domelid is bolted down, and the tank is fitted with hardware that includes a remote operated vapor recovery system from Girard Equipment and OPW Kamvalok dry disconnect system for loading and unloading.
“We get a number of benefits from the way these tank trailers are configured and used,” Slay says. “The closed-loop system means our drivers have no reason to climb on top of the trailers during normal operations, which reduces the risk of falls. Dedicated use means we only have to clean the tanks once a year before the annual retest.”
The trailers have a stainless steel subframe for long life and low maintenance. Running gear includes Hendrickson's Intraax air suspension system with Meritor WABCO roll stability, Michelin X One tires, and aluminum disc wheels.
By July, the first of the 15 tank trailers was ready for inspection at Polar's plant in Holdingford, Minnesota. All of the tractors and trailers ordered by Slay Transportation had been delivered and were in service by mid-August.
Huntsman plant personnel played a key role in visiting the Polar facility at the end of July to review the cargo tank manufacturing process and inspect the first two trailers off the assembly line. This provided key insight into how the trailer were built, and gave an opportunity to review specific safety features built into the trailers. This information enabled the plant personnel to prepare the rest of the shipping group employees for the arrival of the new equipment.
The tractor-trailer rigs are handling eight loads a day each in the Houston and Geismer areas. Slay Transportation personnel preload trailers at Huntsman's Port Neches plant and they unload the Houston-area deliveries. Huntsman workers unload the propylene oxide shipments in Geismer.
“This project has been a great success,” Nordgulen says. “We were able to make significant changes in our propylene oxide logistics system in a relatively short amount of time. We succeeded because this was truly a partnership between us, our carrier, and the equipment suppliers.” ♦
