USING advanced digital automation architecture and a unique approach to project management, Shanghai SECCO beat the schedule for start-up of one of China’s largest petrochemical complexes. The 10-plant integrated facility was constructed in record time: from bare ground to a fully functional world-class ethylene cracker complex in just 27 months, three months ahead of schedule. The plant’s success was due in part to the decision to use a main instrument vendor to manage the project, namely Emerson Process Management , and to use PlantWeb digital automation architecture with Foundation fieldbus to speed construction, deliver ongoing operations and maintenance benefits, and establish an open platform for future growth.
Aims of the project
WHEN SECCO, a joint venture between BP, Sinopec and Shanghai Petrochemical Corporation (SPC) decided to build a new petrochemical facility, the company had three goals:
The complex needed to be a world-class facility that would reduce China’s increasing dependence on petrochemical imports.
The facility needed to give autonomy and control over the production efficiency from the feedstock through to the downstream petrochemical derivatives.
The plant required cutting-edge automation that would give the company a competitive advantage well into the future.
In addition, the complex needed to be built inside an incredibly aggressive schedule, targeting to be operational on a deadline that was only two and a half years after the initial groundbreaking.
Sizing up the project
THE US$2.7 billion ethylene cracker complex is located in Shanghai Chemical Industrial Park in Shanghai Province in China, about 50 kilometres southwest of Shanghai.
In partnership with Emerson, SECCO was also able to work with experts from around the world to help meet its objectives.
Emerson’s experience in the region included several other significant plants, serving as main automation contractor for a seven-plant chemical complex for BASF in Nanjing, China. Emerson also managed the instrumentation for Bayer Caojing, which used more than 300 Foundation fieldbus devices and became operational in September 2002.
The SECCO plant was much larger, designed to meet China’s burgeoning petrochemical needs, reduce dependence on imports, and compete effectively with any plant in the world. The facility will reduce China’s need to import; however, the demand in China is such that even if another of these plants were built every four or five years, China would have to continue to import petrochemicals.
The facility comprises 10 separate plants - plans allow the addition of two more plants if necessary - with a main ethylene cracker capable of generating 900,000 metric tons of feedstock per year.
Other plants rely on this feedstock to produce polyethylene (600,000 MTY), polypropylene (250,000 MTY), styrene (500,000 MTY), polystyrene (300,000 MTY), acrylonitrile (260,000 MTY), aromatics (200,000 MTY), and butadiene (90,000 MTY), as well as the required utility facilities. Another plant in the complex is owned by Lucite, but under contract to be operated by SECCO.
Each of the 10 SECCO plants is the largest of its kind in the world, enabling the facility to produce about 2.3 million metric tons of chemical products annually.
Selecting the project approach and technology
THE project goals and challenges drove the selection of two strategies rarely employed with a facility of this size:
Rather than hiring a general contractor to oversee the project, SECCO elected to use an integrated project management team approach, under which each key plant in the complex had a lead project contractor.
SECCO selected Emerson Process Management as the main instrument vendor (MIV) to not only engineer and implement the automation and control systems, but also to help manage multiple international and local suppliers for each of the 10 plants in the facility.
SECCO also decided to leverage the technologies available in digital, intelligent field devices, selecting Foundation fieldbus communications as a central feature of the facility’s automation approach. Foundation fieldbus not only greatly simplified the construction and commissioning phase, but plant officials also expect it to reduce maintenance costs by as much as a third. Use of fieldbus technology also allows the complex to use truly distributed control. In many instances, the basic process control functions operate within the field devices themselves, rather than in the main automation system.
Targeting a challenging completion date
AN aggressive schedule posed the biggest challenge - to go from bare ground to a fully functional world class facility in two and a half years. As construction plans came into being, a main goal - set in 2001 - was to have the plant operational by July 2005.
At the time, the target date seemed impossible. Meeting target required bringing an enormous ethylene cracker online, making sure that all the downstream units were operational and available, and accomplishing all this with technology that was unfamiliar to many of the team. In reality, construction of some facilities started in early 2003, and the bulk of the work was finished before the end of 2004, and the plant went online in March 2005, in what was considered to be a phenomenal success.
To ensure a smooth launch, the downstream plants were started prior to the ethylene cracker, relying on imported feedstock to ensure everything was in working order. The plants did very well; in particular the polypropylene unit came online very smoothly. The unit even ran out of feed, and it was necessary to shut the plant down to wait for the olefins unit to come online.
The utility boiler start-up occurred on 23 August 2004, and mechanical completion for all 10 plants were completed on 28 December 2004.
The downstream plants were online in February 2005, and the ethylene start-up was 18 March 2005, more than four months ahead of the original schedule. The ethylene cracker was running on-spec in just 10 hours 45 minutes.
Organising for success with MIV approach
SECCO decided that the MIV approach would be best for the project. The MIV would work with SECCO to implement the automation and control systems, and also help to manage the multiple international and local Engineer-Procure-Construct (EPC) suppliers for each of the 10 plants.
The alternative to working with a single MIV would have been to work directly with many different instrument companies; this would have meant the project losing a tremendous amount of efficiency and consuming much more time. With the MIV strategy, once the mechanisms of various units were understood, the learning was applied to the others, making many of the processes fairly interchangeable.
Learning the intricacies of one company’s products, rather than those from several different companies, saved time and money in warehouse storage for spare parts and new components.
After evaluating several different suppliers, Emerson Process Management was chosen, both for their breadth of digital automation, including quality field instrumentation and systems, and for their experience in managing projects of this scale.
Emerson and SECCO created framework agreements for all EPC contractors to use, enabling consistency across the site for current and future operations. This was key to SECCO’s long-term goals of ease-of-use and reduced maintenance, making sure that every process in each of the 10 plants was developed consistently.
As MIV, Emerson developed functional design specifications, and communicated and enforced conformance and standardisation by every vendor as applicable throughout the facility, a vital step in maintaining operating efficiency in the tightly integrated complex.
Emerson actually provided separate teams for each of the 10 plants, rather than having a single team moving from one plant to the next, and also appointed a program director and an engineering and quality manager to oversee all plants. This MIV organisation was crucial to the goal of a fast start-up.
The MIV approach was also critical to the success of the SECCO strategy of using a single control room for all 10 plants. In order to economically connect all the various systems, including 14 outstations, to a single control room, all the systems needed to be consistent.
Emerson’s MIV leadership helped give the uniformity, and digital automation architecture with Foundation fieldbus communications provided the needed technology.
The MIV strategy was especially important because about two-thirds of the SECCO in-plant staff were fresh graduates, which meant needing to depend on outside training and assistance. Integrated project management teams were created comprising SECCO employees, Emerson staff and EPCs during the internal testing and Factory Acceptance Test phase.
The core Emerson/SECCO team developed the functional design specifications (FDS) over about five months, and then presented it to the control managers of all plants for review and fine tuning. A simulation was created of one heater of the ethylene plant; this enabled further refining of the specifications with all the various graphics and control models. The simulation was also fine-tuned for one of the polyethylene processes to enable better understanding of the process when writing the sequences template.
The engineering manager in the core FDS team eventually became the master editor of the functional design specifications - every new module anywhere in the plant needed to be created by him, keeping the 10-plant facility consistent. In addition to being the master editor of the 1000-page FDS, comprising 14 Sections and 14 Appendixes, he also became the master trainer, which was key to a successful start-up.
Applying the digital automation
EMERSON’S PlantWeb digital architecture is used throughout the complex, which is the largest Foundation fieldbus installation in the world. Over 10,000 of the plant’s 20,000 devices are networked with fieldbus technology to deliver digital process, control, and device diagnostics information.
Overall, the facility comprises over 48,000 loops, with about 166,000 I/O tags.
Around 25,000 points are hardwired to the automation system. There are over 70,000 cables in the facility. The digital architecture integrates 10 DeltaV systems with a single global historian and remote operations functions. All 10 automation systems are managed from a single centralised control room, something that would not have been possible without the Foundation fieldbus technology.
Application of PlantWeb digital automation technologies makes the SECCO integrated complex the most advanced facility in the world.
Foundation fieldbus technology choice from the start
THE Foundation fieldbus devices and systems gave several advantages, including openness and intelligent asset management. While the most appropriate instrumentation was selected for each process, not all the devices were available from Emerson.
The ability to integrate other supplier devices really brought out the flexibility of PlantWeb with Foundation fieldbus, since this automation is designed around an open, standards-based platform on which industry-wide devices can participate.
The decision to go fieldbus originated in 2001, when BP was reviewing technologies and setting the goals for the facility. Even at that time, BP viewed Foundation fieldbus as a leading edge, but mature technology with tremendous advantages for end users. During commissioning especially, the advantage of the devices’ intelligence helped reduce the elements of loop testing that would have been necessary on a traditional start-up.
Based on the benefits realised, SECCO has since made it a policy that all greenfield projects be implemented with Foundation fieldbus technology.
The technology has been used many times in the petrochemical industry over the past few years, and the massive scale of use and success of SECCO proves Foundation fieldbus value for most major projects. Benefits include:
• Increased reliability and accuracy.
• More seamless, richer information, easing troubleshooting to a huge degree and reducing the resources required for maintenance. SECCO estimates, in fact, that this will cut their maintenance expenditure by one-third.
• A means of preparing for the future. SECCO sees fieldbus as a leading-edge, quality technology with natural advantages that will raise its standards and business practices across the board, and help increase the net profit of the facility.
While SECCO knew that a fieldbus approach would save considerable amounts of cabling, a conservative approach was taken to the number of devices connected on each segment.
Designs were limited to no more than 12 devices, and the average ended up as five devices per segment, where each segment varies between two to 11 devices.
Foundation fieldbus enabled performance of basic PID control in the intelligent field devices. The choice was made to locate the PID algorithms at the point of final control - in the valve controllers. This Control-in-the-Field (CIF) helps give the improved reliability of a truly distributed control system.
CIF also significantly reduces the communication between the automation system and the field devices, adding to increased reliability.
Only single-loop control was implemented in the valves - all complicated control, such as cascade and multi-element strategies, is done in the DeltaV digital automation system. Control function blocks could be performed in any of the field devices, or in the automation system, since it is an easy drag-and-drop software choice. This easy configuration will save time as SECCO modifies its ever-changing plant.
In actual application, Control-In-The-Field was implemented with no major problems. The benefits haven’t been quantified yet, but a long-term advantage is expected for the SECCO plant.
Asset management aids commissioning and future operations
THE intelligent field devices also deliver process and equipment health information to the AMS Suite within PlantWeb.
While SECCO is still discovering the benefits of the Asset Management system, it has already provided great value in key areas, such as allowing us use of the AMS Suite: Intelligent Device Manager that enables verifying the range inside the transmitter, while sitting in the comfort of the control room. The AMS ValveLink application is being used to obtain valve signatures so SECCO can monitor valve status and take action to optimise performance, and avoid abnormal situations.
The asset management suite will greatly improve the lifespan of the complex’s assets by enabling the “predicting” and taking action to prevent any problems before they actually occur.
For example, it is possible to look at all the information coming from the intelligent valves and understand the changes in the friction coefficients to know if there’s a potential for leakage or early breakdown.
The predictive diagnostics of PlantWeb and AMS Suite will help optimise SECCO’s maintenance plan, enabling personnel to focus directly on the problems, which will greatly improve efficiency and minimise downtime. Knowing what the problems are beforehand, the staff can schedule maintenance and obtain the needed parts. Where there are no problems, the maintenance schedule can incorporate delays accordingly. This is a clear advantage over traditional plants that may tear down and rebuild equipment every two years, whether or not it is needed.
Importance of teamwork
SECCO worked closely with Emerson’s Shanghai Engineering centre, and also received a lot of support from the company’s Global Support Services in Manila, and company headquarters in the United States.
SECCO also worked closely with Emerson to contain costs for the project.
Emerson gave SECCO a lot of support in the negotiation process, adopting a relatively flexible strategy that allowed SECCO to reach agreements with the various EPC suppliers and sign an extremely efficient MIV contract. Following that, Emerson also provided support during the engineering construction process, which allowed intimate coordination with the EPC suppliers throughout the project.
SECCO knew also that by selecting Emerson as MIV, they were reducing their risks. The most vital aspect of any petrochemical facility is reliability of the control system and a high level of reliability, helping SECCO to hold a strong competitive edge in the instruments; control of the plant will rely much more on the automation equipment than on the operators. They fully expect the digital automation installed by Emerson to achieve market.
* Commentary by Adrian Howell, process control manager, SECCO, and Stanley Ee, program director, Emerson Process Management.