THE TEPPCO Partners LP marine propane terminal on the Providence River in Providence, Rhode Island, loads 80 to 100 tank trucks per day in the winter.
At dockside, ships carrying propane arrive about 10 times during the year, mostly in winter. Handling all that traffic on the 10-acre site requires a maze of storage and terminaling equipment, computerized controls, and a well-trained workforce. Added to the standard operating procedures are new security measures now required as a result of concerns about terrorism.
“We've done a lot of upgrades in the last four years that have improved efficiency,” says Brian Nielsen, Providence terminal area manager. “For example, the truck loading rack rate was improved from 300 gallons per minute to 580 gallons per minute.”
The company has placed additional emphasis on employee training and hired trainer coordinators. Training has been stepped up in areas of safety, equipment handling, and governmental regulations.
“Specialized training is required for this terminal because of the equipment we have here for handling the product,” Nielsen points out. “Employees receive instruction for various processes, such as the compressor system.”
In addition, new rules have come down for port facilities from the Coast Guard and other federal agencies to enhance security.
“Our terminal was always fenced and gated,” he says. “With our proximity to downtown, there were always significant security procedures in effect when the ships arrived. Now, that's been increased significantly. We have had to add to the security duties here — obviously being more aware of our surroundings, looking out for suspicious things, just using common sense.”
With new security measures in place that require driver scrutiny, the terminal has made an effort to make the procedures run as smoothly as possible. Identification cards, card scanners, and other computerized equipment have increased the time it takes for drivers to enter, load, and be on their way, but enhancing the loading rate has helped offset the security delay.
Driver relationship
“We've got a good relationship with all of the carriers that come in here,” Nielsen says. “We have a terminaling agreement with Duke Energy Natural Gas Liquids, so they have the initial contact with the trucking companies, but obviously we want to make this a place that is driver-friendly. Most of these drivers have been coming in for years, and our employees are veterans as well. You get people that know each other and have good rapport.”
Trucks roll into the terminal around the clock, which means a 24/7 calendar for the facility. “Carriers have a variety of delivery demands, and we are committed to meeting them,” says Nielsen. “For example, some carriers are transporting propane to Martha's Vineyard and Nantucket Island, which requires meeting ferry schedules.”
In 2002, the company decided to enhance loading efficiency by rebuilding existing Worthington product pumps and installing new 100-horsepower US Electrical motors. Propane is pumped from the storage tank through heat exchangers and to the truck rack.
As soon as drivers arrive at the loading rack they begin putting safety measures in place by removing the truck ignition key and hooking it onto the loading arm. The key won't be removed until the loading is completed and the arm disconnected.
“It's just a good procedure to prevent drivers from moving the truck with the arm still connected,” says Nielsen.
After manipulating the Emco Wheaton loading arm and coupling the Acme fittings to the trailer, drivers enter a nearby building where a Toptech Systems Inc remote control computer terminal is located. The equipment includes a graphical display, keypad, and card reader all mounted in a heavy-duty metal enclosure.
Drivers swipe their identification cards through the card reader and enter information: a password; tractor, trailer, and account number; and product destination. Inside the terminal office, an operations and maintenance (O&M) apprentice monitors the procedures on interfaced equipment.
As soon as product begins flowing into the trailer, drivers check for any leaks at the trailer and loading rack, and then stand by until the loading is completed — usually in less than 20 minutes.
TEPPCO has been serving propane carriers at the terminal, the only refrigerated LPG facility in the company, since 1990 when it purchased the facility. The company conducts business through various subsidiary operating companies and owns and operates one of the largest common carrier pipelines of refined petroleum products and liquefied petroleum gases (LPG) in the United States. The company also operates petrochemical and natural gas liquid pipelines and is engaged in crude oil transportation, storage, gathering, and marketing.
TEPPCO owns the only pipeline that transports LPG from the upper Texas Gulf Coast to the Northeast region of the United States.
LPG customers include refiners and propane wholesalers and retailers who sell to commercial, industrial, agricultural and residential heating customers. The company operates in Arkansas, Colorado, Illinois, Indiana, Kentucky, Louisiana, Missouri, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, Texas, West Virginia, and Wyoming.
The Providence terminal is part of the company's downstream segment. Operating divisions include interstate transportation, storage and terminaling of refined products and LPGs, short-haul shuttle transportation of LPGs, and intrastate transportation of petrochemicals. In the first quarter of 2004, the downstream segment reported $25.7 million in operating revenue.
At the Providence terminal, 14 employees have various duties, depending on their training and expertise: some handle instruments, some electrical equipment, others piping.
“They all have to know every piece of the process that goes on at the terminal,” says Nielsen.
There are five operators, one technician, and eight operation and maintenance apprentices who work 12-hour shifts. The apprentices are either active- or retired-duty firemen from the area, which gives the workforce added safety qualifications.
Applicants must have a two-year college degree or equivalent work experience. Nielsen, a training coordinator, and a safety coordinator direct the training program, which includes Coast Guard-mandated procedures, company policy, and on-job training.
The employees are involved in seeing that propane delivery is constant for the ever-entering trucks. Supply for the loading racks comes from the 400,000-barrell (16-million-gallon) storage tank that receives propane from 550-foot- to 700-foot ships that dock nearby. Product with a temperature of -42°F unloads at 650 metric tons (8,000 barrels) per hour.
“Ships are our only source of product,” Nielsen points out. “We think of our storage and terminaling facilities as similar to a TEPPCO pipeline that moves products for customers.”
Because the company does not own the dock property, the company uses a mobile offloading unit with FMC equipment to transfer propane from ship to the double-walled, fixed-roof storage tank. Two feet of insulation is installed between the walls to maintain product temperature. Praxair supplies the terminal with nitrogen that is used to purge the area between the walls.
For spill protection, there is a 52-ft steel containment dike that surrounds the tank and is about one-half the height, as well as a 17-ft berm. Throughout the system process, safety measures are in place that will automatically activate should there be an incident. In an emergency or shutdown, product can be flared from a 90-foot stack on the facility. A natural-gas Waukesha generator is available should the terminal lose electrical power.
Heat exchangers
As the fuel coming off the ship is at a -42ÞF, a process has to be in place to raise the temperature to 34ÞF for hauling by tank trailer.
Propane is pumped from the storage tank to the heat exchangers that are composed of heating tubes filled with water glycol solution. To insure a steady supply of product, the terminal has two Teledyne Lars boilers that are natural-gas fired and two Superior boilers that are propane-fired. The boilers can go online as needed.
After the propane is heated, it goes to the metering skid to be loaded into the truck. In addition to the temperature adjustment, equipment injects ethyl mercaptan into the product as an odorant.
In order to maintain pressure through the system and to keep the product refrigerated, the company uses one of two 150-horsepower Chicago Pneumatic Tool Co compressors. The compressors are rotated on seven-day intervals in a lead/lag arrangement. The lead compressor comes on when needed. If the lead compressor cannot reduce the pressure alone, the lag compressor comes on to add its energy to the task.
Inside the terminal, the control room houses computers that automatically oversee the system. The main control uses a Ronan Engineering Company annunciator panel that monitors the refrigeration system and various alarms. The panel also handles General Monitors equipment that detects gas and flame, as well as Fisher flare controls, Enraf tank gauging system, and emergency shutdown capability.
The truckloading system in another part of the control room is linked into the main control. It uses a Siemens programmable logic controller to handle truck rack operations.
All of the equipment and manpower at the Providence terminal is reflective of the company's stated goals to increase LPG services, as well as those for other petroleum products.