While the importance of liquefied natural gas

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					      The Case for Digital Technology
      in the LNG World
      by David R. Reif
      Global Lead, Hydrocarbon Industry Sales and Marketing
      Mark Kennedy, Director-LNG
      Emerson Process Management

          W            hile the importance of liquefied natural gas
                       (LNG) as an energy source grows throughout
                       the world, recognition of digital technology is
          growing as an important means of improving each function
          during liquefaction, transportation and regasification.
          In fact, one of the best ways to avoid problems in LNG
          plants is through the application of comprehensive digital
          technology that connects measurement devices and host
          control equipment via a serial, two-way communications
          protocol. This establishes a data-rich environment for
          understanding the condition of critical LNG processes               prevent abnormal events that can lead to a safety or
          and equipment, as well as predicting when and where                 an economic incident
          malfunctions may occur.                                           • A data-rich digital automation structure to precisely
             One fully digital technology, widely implemented in              diagnose the status and trend of operations and to
          the United States and gaining worldwide acceptance, is              optimize overall facility performance
          the FOUNDATION™ Fieldbus (FF) protocol. It offers                 • The ability to more fully integrate safety systems
          potential paybacks in the form of reduced life-cycle costs
          with savings for installation, commissioning, maintenance       Troubled LNG Plants
          and improved access to information.                             Recent outages at liquefaction plants worldwide have
             According to David S. Lancaster, Bechtel USA, and            squeezed LNG supply and raised important questions
          Brain Parkes, Bechtel UK, in their report "Fieldbus             about LNG processes and procedures. Details on the
          Technology for the LNG Process – A Viable Option?"              causes of shutdowns are hard to obtain, but engineering
          (LNG Journal, November/December 2002), "the benefits            sources stress that each occurrence has been different
          to the Owner/Operator offer significant reasons to use          and failures do not seem to be comparable. "Sometimes
          Fieldbus technology in the LNG process."                        it’s a design fault; sometimes it’s an operational mistake.
             The FF protocol is an essential characteristic of advanced   It can depend on plant location, feed-gas composition,
          digital plant architecture, which employs a unique bus          choice of liquefaction process, age of the plant, choice
          technology to create a web of digital components for the        of contractor – all this has to be taken into account,"
          operation and control of processes commonly found in            according to one industry source.
          LNG facilities. Digital architectures offer LNG companies
          an unparalleled opportunity to improve plant performance
          while actually reducing overall costs. As shown in
          Figure 1, this technology impacts quality, throughput
          and plant availability to improve output, while it is an
          equally strong influence on lowering costs for operations/
          maintenance, safety, utilities and waste materials.
             For these reasons, anyone constructing or operating LNG
          facilities should seriously consider digital technology for:    Figure 1: LNG companies benefit from digital automation
             • The best possible predictive intelligence system to        architecture.

74   World Energy              Vol. 8 No. 4       2005
          Nigeria LNG (NLNG) announced a closure of trains                                                                           termed an abnormal situation. Potentially, such a condition
        2 and 3 in late August following a leak and fire in the                                                                      can cause a negative impact on product quality, through-
        main gas supply pipeline to the liquefaction facility.                                                                       put, production equipment and the environment. It can
        Repairs were concluded September 27, when a project                                                                          also pose a safety threat leading to injury or loss of life.
        spokesperson confirmed all trains were producing at full                                                                        Too often, abnormal situations become emergency
        capacity "in quantity and quality."                                                                                          situations. The U.S. petrochemical industry has quantified
          Australia’s North West Shelf was quite open about a                                                                        the cost of abnormal situations to be in the range of
        shutdown at Train 4 that began August 28, saying the                                                                         $700 million per year, according to a paper presented by
        problem was caused by damage to the blades and rotor of                                                                      Evren Eryurek, Pete Sharpe and Douglas White of Emerson
        the plant’s mixed refrigerant compressor. This outage,                                                                       Process Management at the 2005 annual meeting of the
        which might have been prevented if predictive intelligence                                                                   National Petrochemical & Refiners Association held
        had been available, cost approximately nine cargoes.                                                                         this past March. Obviously, preventing the problems
          When a three-week outage occurred at the Spanish-                                                                          preceded by abnormal situations is a worthy objective,
        Egyptian LNG (Segas) project in Damietta, Egypt, it was                                                                      leading to safer operations, increased productivity, higher
        announced the shutdown was scheduled to "overhaul the                                                                        product quality and less equipment damage.
        turbines after running for 8,000 hours." Again, better                                                                          One of the best ways to avoid problems is through the
        information on the condition of these machines might                                                                         application of a comprehensive digital technology that
        have enabled the plant to run them longer.                                                                                   enables the establishment of a data-rich environment
          All in all, supply losses due to the unplanned shut-                                                                       and leads to greater understanding of conditions inside
        downs resulted in about 30 cargoes (1.7 million tons),                                                                       LNG processes and equipment. Abnormal situation
        equivalent to roughly 80 billion cubic feet (Bcf) of gas.                                                                    prevention (ASP) is achieved by predicting the health of
        Of course, the current market environment makes such                                                                         field devices, process equipment and process conditions
        losses more visible.                                                                                                         and by integrating them with operational knowledge and
          Engineers and builders insist the spate of outages is a                                                                    procedures. An example of ASP technology is available
        normal consequence of the increasing number of LNG                                                                           through Emerson as the company’s PlantWeb® digital
        production sites. "The more plants you have, the more                                                                        plant architecture gathers predictive information, which
        opportunities there are for something to go wrong," is                                                                       is used as the basis for early warnings, even before a
        the litany. On the bright side, certain new technological                                                                    situation passes from "normal" to "abnormal" and long
        developments promise to increase plant availability by                                                                       before it becomes an "emergency" negatively impacting
        preventing the situations that lead to trouble.                                                                              operations (Figure 2).
                                                                                                                                        As shown in Figure 3, the digital architecture comprises
        Abnormal Situation Prevention                                                                                                a network of intelligent field devices, scalable control and
        A disturbance or a series of disturbances in a process that                                                                  asset optimization systems, modular software and safety
        causes plant operations to deviate from their normal                                                                         systems. In this digital approach, today’s smart fieldbus
        operating state and resulting in operator intervention can be                                                                devices run online diagnostics to continuously monitor

                        Normal                                              Abnormal                                 Emergency
                                                                                               Corrected Situation

Impact to Operations

                                                      Corrected Situation




        Figure 2: Predicting abnormal events reduces impact to                                                                       Figure 3: Digital plant architecture supplies predictive
        operations.                                                                                                                  intelligence for LNG facilities.

                                                                                                                                                  World Energy                  Vol. 8 No. 4        2005   75
         their health and that of the process, and to deliver the           Predictive maintenance works throughout LNG
         information to control and asset-management software            facilities, where smart digital instruments continuously
         and operator/maintenance/engineering workstations.              run diagnostics to generate real-time information about
         This enables predictive analytic and diagnostic solutions       their health and the process health. The resulting data
         not available elsewhere. Abnormal events can be detected        comprises predictive intelligence that is used to guide
         through advanced pattern recognition, multivariate signal       maintenance activities on those devices and the produc-
         analysis and statistical process control.                       tion equipment to which they are mounted. With such
            Early warnings based on these technologies can be in         knowledge, personnel are able to determine whether
         the form of device alerts that provide information on a         immediate action is required to prevent a failure or
         specific field device for maintenance purposes or ASP           whether the equipment can continue to operate until the
         process unit alerts that make operators aware of specific       next regularly scheduled shutdown. Actions based on
         process conditions long before a conventional distributed       predictions increase the reliability and longevity of critical
         control system would recognize developing problems. By          components, and fewer costly interruptions result.
         the time a conventional shutdown system is activated, it           Progressive companies are now complementing
         might be too late for corrective action.                        predictive maintenance with asset optimization – a
            For instance, ASP can be used on refrigerant compressor      blending of technologies and services that unleash
         gas turbine drivers to predict or diagnose abnormal             underutilized capabilities in a plant. As a result, the
         conditions before vibration monitoring systems or a             production system is empowered to equal or exceed the
         catastrophic incident creates a shutdown situation.             results it was designed to deliver, and the higher level of
         Additionally, advanced process control (APC) can provide        performance is maintained indefinitely.
         state-of-the-art– anti-surge protection while reducing             Process-automation suppliers are providing asset-
         overall process variability, thereby safely permitting          optimization expertise and technology. More than
         increased LNG production.                                       1,800 Emerson personnel support the company’s work
            Likewise, vaporizer banks on regas terminals can benefit     with customers around the world. Service experts apply
         from applications that improve burner management                applications from what is the industry’s broadest suite of
         for fired vaporizers, yielding a cleaner burn, reduced          asset-management software. For example, the Equipment
         emissions and improved fuel efficiency, while preventing        Performance Monitor application, which is currently
         erroneous flame-out trips.                                      in use in LNG facilities, enables a move from reactive
            The monetary value of loss avoidance and increased           maintenance (repair it after it breaks) to predictive
         production possible with abnormal situation prevention          maintenance on critical production equipment including
         makes this a must-have digital technology.                      gas turbines, compressors and heat exchangers. Among
                                                                         the operational benefits are improved performance
         Asset Optimization                                              across trains, greater uptime, improved throughput and
         For several years, the process industry has recognized          increased profitability. On the maintenance side, employees
         reliability-centered maintenance as a means of maximizing       are no longer fighting to stay ahead of breakdowns
         the service life of critical production equipment and           because they have advance knowledge of those assets
         reducing or eliminating unwanted downtime. Under                most likely to encounter problems and can fix critical
         this concept, production components whose failure               components before the overall operation is impacted.
         could cause an unexpected plant shutdown are given                 Asset-optimization applications can be utilized to
         maximum attention by maintenance personnel, whereas             monitor and optimally run critical equipment, such as
         equipment that will not greatly affect plant operations         high-pressure pumps used to feed vaporizers, refrigerants
         upon failure is given only routine maintenance to preclude      and boil-off gas compression systems. Data developed
         a premature demise. Some noncritical equipment is               through online or portable vibration monitors, oil
         simply allowed to run until it fails and is then replaced.      sampling, sonic detection and infrared thermography
            The vast amounts of data generated by smart field            can be analyzed to determine the condition of pumps
         devices regarding their condition and associated equipment      and other types of rotating equipment. Potential faults
         are the basis for predictive maintenance. This is a step        can be identified before they occur, and the equipment
         beyond the reliability-centered maintenance concept             replaced or repaired before a failure causes a shutdown.
         because the predictive approach relies on field intelligence       Greater plant availability and increased productivity
         as the essential element in predicting the future operability   are long-term benefits – another strong argument for
         of any piece of equipment.                                      standardizing on digital instrumentation in LNG facilities.

76   World Energy             Vol. 8 No. 4        2005
Safety Instrumented Systems                                         before they can cause problems. A sophisticated digital
Digital plant architecture has now been extended to                 architecture, such as PlantWeb, actually improves facility
safety applications. The resulting smart safety instrumented        performance and reduces costs in various ways.
system (SIS) is the first to provide an integrated approach            In market times like these, it is imperative for LNG
to entire safety loops, from sensor to logic solver to final        operators to have at their disposal the best possible
control element. It is also the first to use digital intelligence   information about their facilities in order to prevent
and diagnostics to enable more automated safety-loop                abnormal events that could lead to a safety or economic
testing and other elements that increase system availability        incident. A digital automation architecture is necessary
while reducing life-cycle costs and easing regulatory               to generate and gather data-rich information needed to
compliance. The digital SIS helps users increase the                determine the status of an operation, diagnose potential
safety of their facilities.                                         problems and optimize performance. Finally, an integrated
   The fully integrated digital SIS maintains the required          safety system provides security for all personnel, structures
safety system segregation while providing a consistent              and LNG processing and transporting equipment. n
and efficient interface platform for monitoring and
operating fire and gas, emergency shutdown and jetty
management systems along with the main process                      David R. Reif has more than 25 years experience in the
control system. This monitoring and process control can             area of hydrocarbon industry automation. He began his
be executed from any integrated workstation on the                  career as a process engineer with Fluor Daniel Engineers
facility, such as from the jetty control room. The digital          and Constructors in Houston, Texas. While there, his
architecture enhances process intelligence, facility safety         primary focus was on refining and gas processing
and operational flexibility.                                        projects; performing process design, checkout and start-
   The digital SIS host system provides a full palette of           up operations on numerous refineries for such clients as
smart function blocks that are specifically designed for            Texaco, BP, Phillips Petroleum, Mobil and Aramco. He
safety functions and can be commissioned by a simple                joined Emerson in 1985, initially in Emerson’s Rosemount
drag-and-drop configuration activity. The system delivers           Division as Hydrocarbon Industry marketing manager.
version control and audit trail capabilities within its             Since then, Mr. Reif has held numerous positions in Division
software, and the Intelligent Device Manager software               and Corporate Marketing and Sales. In 1992 he became
helps to automate IEC 61511 compliance. Changes are                 the director of Multinational Project Sales for the Fisher-
recorded in the smart SIS solution, including date, time,           Rosemount Group of companies under Emerson. In 1998
author or respective level. Plant Messenger directs events          he joined the Emerson Process Management Corporate
requiring corrective action to the relevant department, and         Sales Group as vice president of Global Hydrocarbon
Plant Event Historian automatically documents all events.           Industry Sales. He currently holds the position of global
   Emerson’s integrated smart SIS solution is easy to use           lead, Hydrocarbon Industry Sales and Marketing.
and has the same design tools and operator interface as
the main control system to simplify and enhance the                 Mr. Reif holds a bachelor of science degree in chemical
safety response and security systems. It is also is scalable.       engineering from the University of Minnesota and a
Additional safety loops can be added when needed, and               M.B.A. in finance. He has been a member of the
a system of any size can be fashioned without gateways or           American Petroleum Institute’s Committee on Refinery
other extra components. As the system expands and I/O               Equipment since 1988. He has both presented and
(input/output technology) is added, performance is not              published numerous papers in the areas of digital
degraded and safety is not compromised. As a result,                automation architecture and advanced process control
plant uptime is improved and expansion costs are reduced.           for the hydrocarbon facilities.

The Promise of Digital Architectures for LNG                        Mark Kennedy is director of LNG for Emerson Process
Digital architectures offer LNG companies an opportunity            Management, heading up Emerson’s global focus on the
to avoid some of the operating and mechanical problems              LNG industry. His career in the industry and international
that have befallen some industry facilities in the past             projects spans 25 years in engineering and management
few months. Smart digital field devices generate a vast             roles representing global operators, engineering and
amount of information that can be used to establish a               construction firms and suppliers. Mr. Kennedy earned a
predictive maintenance environment, providing early                 degree in electrical engineering from George Washington
warnings of degrading mechanical conditions long                    University and an M.B.A. from Wake Forest University.

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