Ineos Chlor reduces fuel costs through better control
Advanced control using Emerson's PlantWeb reduces hydrogen venting and increases fuel supply to onsite boilers.
The Ineos Chlor facility at Runcorn in the U.K. has reduce annual fuel costs by approximately $4.5 million using Emerson Process Management's PlantWeb advanced control and predictive maintenance technologies. The plant has been able to reduce venting of hydrogen, retaining it for use as a fuel to heat onsite boilers for power generation.
Ineos Chlor is one of the major chlor-alkali producers in Europe and a global leader in chlorine derivatives. Its Runcorn operation uses two methods of chlorine production: mercury cell electrolysis, and a newer membrane chlorine plant (MCP) process. Hydrogen is a by-product of both methods. The plant's automation team reduced purchased-fuel costs by developing a new control strategy using the capabilities of Emerson's PlantWeb architecture, including a DeltaV digital automation system. The strategy directs more of the excess hydrogen to the plant's boilers which had not been practical earlier. The system has to control wide variations in hydrogen gas pressure that tended to cause boiler trips and equipment damage before the improvements.
"The great thing about the DeltaV system is the wide range of programming function blocks available and the ability to write customized code," explains Philip Masding, process control manager, Ineos Chlor . "The system itself is extremely flexible and powerful, and allows you to do pretty much whatever you want so long as you have the imagination to take advantage of its capabilities."
Instrumentation that is also part of the PlantWeb architecture provides accurate measurement and control essential to the new control strategy's success. Emerson's Rosemount pressure and flow devices and Fisher intelligent valves are used throughout the compressor, boiler, and chlorine processing plants. These devices are networked using Foundation Fieldbus, and Emerson's AMS Suite predictive maintenance software and AMS ValveLink software tool are used to monitor instrument status and verify the valves are working properly.
The Ineos Chlor team also implemented a new monitoring system to calculate venting totals and costs automatically based on actual gas prices. Hydrogen venting has been reduced by 90%, with the resulting increase in hydrogen available as fuel saving approximately $4.5 million a year in natural gas costs. The improved control has also prevented 10 or more boiler trips and dozens of events that would have exposed manufacturing equipment to potentially damaging high pressures.
-Edited by Peter Welander, process industries editor, PWelander@cfemedia.com
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