Blend Control Software Permits Capacity Expansion
Established in 1999 following the merger of Petrochemia Plock SA and Centrala Produktow Naftowych SA, PKN Orlen has grown to become the largest distributor of fuels in Central Europe and Poland's largest refiner of crude oil. The company operates 1,900 gasoline stations in Poland and 500 in northern Germany.
Established in 1999 following the merger of Petrochemia Plock SA and Centrala Produktow Naftowych SA, PKN Orlen has grown to become the largest distributor of fuels in Central Europe and Poland's largest refiner of crude oil. The company operates 1,900 gasoline stations in Poland and 500 in northern Germany. Other products produced by PKN Orlen include diesel oil, furnace oil, aviation fuel, plastics, and petrochemicals.
With its market share rising and added production requirements stemming from joint ventures with other companies, PKN Orlen sought to increase its ethylene production capacity from 360,000 to 660,000 metric tons per year and its propylene production capacity from 130,000 to 315,000 metric tons per year and enable quicker process changeover between products.
"We could consume 20 million tons of crude oil per year company-wide, but we were unable to process that much," says Waldemar Nagórko, PKN Orlen's senior automation manager. "We had to extend the capacity of our plants to eventually enable us to consume everything that we can distillate."
The company turned to ABB Process Industries GmbH, Mannheim, Germany, to provide a system upgrade that would permit higher production volumes and shorter time to market. ABB's operations in Houston, TX, provided the associated software.
Under the terms of the contract, ABB was slated revamp PKN Orlen's 21-year old plant in Plock, Poland—an integrated refinery and petrochemical complex that is regarded as one of the 10 most modern and efficient facilities of its kind in Europe. ABB performed the initial design at its offices in Germany; a combined team of ABB engineers and local contractors in Poland handled implementation. PKN Orlen also required that PKN Orlen plant engineers and operators had to be able to program and run the system themselves without consultation with the vendor, and the installation had to proceed in the shortest possible time with a minimum of lost production.
The $165 million job was slated for delivery to PKN Orlen by the end of 2004. ABB completed the changeover months ahead of schedule with only a two-week plant shutdown.
The distributed control and optimization systems at the Plock blending plant were based on previous ABB technology (Lummus). According to Nagórko, PKN Orlen selects vendors based on products and on the relationship. Their existing relationship encouraged PKN Orlen to choose ABB for the upgrade.
"This transition is a good example of another step in our company's evolution from a very traditional control system to a very advanced one," says Nagórko. "We introduced our first computer-based distributed-control systems only 10 years ago. Before that, we relied on pneumatic control with a few electronic-type measurements. We began with a single-node ABB MOD300 Distributed Control System for controlling jet fuel and alcohol production.
"Eight years ago, our blending plants employed a one-node system. New market demands, more restrictive product specifications, and the need for more flexibility in component usage led us to modify and extend the number of component lines and to control more product properties. There are many examples in the company where we started with a single node that handled only balance and other types of mandatory measurements, which were then expanded to a huge control system that delivered a better product at higher levels of production."
In 1998, the company decided to extend its operations to allow production of a full range of gasolines and commissioned its first blending control and optimization system. ABB's SC industrial microprocessor-based hardware controllers and Advant stations—Unix-based computers running process-operator software that can combine with engineering, historical, or data analysis tools—were added to the existing single multibus node in use at the time. On- and off-line process optimization and planning were performed on an Advant Information Management Station (IMS). A near-infrared technology analyzer performed on-line properties measurement of gasoline products and components, providing feedback to the optimizer and allowing corrective action to the process if necessary.
"We utilize three DCS vendors within the company," says Nagórko. "ABB provides an easy migration path to its new products and to extend these systems. Even a step change to system operation does not require replacing hardware to take advantage of the latest software developments. Not all vendor products permit that kind of compatibility."
To address PKN Orlen's requirements at the Plock facility, ABB suggested its Advanced Blend Control (ABC) product. An OPC server was added to the system as an interface with the ABC server that ran all optimization and planning software. The ABC software package was interfaced to the open control-system architecture of ABB's Advant on-line control system using MOD300 software.
"Orlen engineers developed all software in a third-party DCS system called Ratio Blend Control. ABB prepared the ABC database and configured the system," says Nagórko. "We trained our people on the ABC server so that we can make any future modification ourselves—adding tanks, components, product grades, and lineups, for example—without vendor assistance."
ABC features an open architecture (using an Oracle database), allows component and product tank swings based on defined criteria, and permits unlimited access by privileged users. The open architecture of the system also allowed interfacing to other plant systems, including the laboratory information and tank information management systems for data collection and analysis, as well as the plant's strategic and operational planning systems.
"We can pass design data straight through the tools directly to the system database, greatly reducing the number of possible mistakes," says Nagórko.
Plant supervisors can now accept, modify, create, and optimize recipes from the control-room level during night or holiday shifts, off-site. They can adapt process conditions to the production plant's status, accounting for plant upsets and unexpected changes of components.
PKN Orlen personnel—including lab technicians, process engineers, plant managers, and operational planning engineers—routinely exploit the capabilities of Advanced Blend Control. For control-room operators, the software provides a window to the DCS console. Although information is accessible from anywhere, administrators grant each user different access and control privileges to guarantee the system remains secure. In addition, the control room operator must confirm any command coming in remotely from ABC to the digital control system. For safety reasons, if the operator doesn't react in a predetermined period of time, the DCS software will make the safest (predetermined) decision to protect the process.
The blending facility at PKN Orlen's Plock site was sized to handle 4 million tons of gasoline per year and achieved targets with the control-system upgrade, including optimized costs, reliable prediction of and control over product properties, reduced production costs and giveaways, and virtual elimination of reblends.
PKN Orlen operators and engineers also gained access to knowledge about the blending process to which they could respond for correction or improvement, permitting modification and system extensions. For example, to allow use of components directly from production plants rather than only from storage tanks, the company will install an analysis system that measures properties on product and component lines directly. The DCS and ABC software can then be adapted to apply that information to correct product recipes online in real time. ABC's techniques for industrial batch products allow PKN Orlen to sell custom products "on-spec," reducing or eliminating the need to reblend, thereby lowering production costs.
According to Nagórko, PKN Orlen has only just begun introducing industrial-type information technology products within the company for networked analysis, control, and information feedback. With all of PKN Orlen's control systems now connected to the refinery's information infrastructure, the company's networked approach enables transfer of information from the plant floor to management enterprise systems for tactical and strategic business planning, as well as for production optimization.