Model-based Advanced Control Solution Saves Energy on VCM Plant

Plant operations today are faced with ever-increasing pressure to improve efficiency, quality and productivity. Vinyl chloride monomer (VCM) is one of the many high-valued products made at LG Chem Ltd., and VCM production must be adjusted to meet upstream and downstream requirements. There is great incentive to provide a control solution that can improve VCM production and improve the stability of the unit operation. Using Honeywell advanced solutions, profit controller (robust multivariable predictive control technology (RMPCT)) in conjunction with Technip´s EDC CRACK rigorous yield model, the LG Chem VCM II plant in Yeosu, Korea has experienced (1) VCM production increase when demand allows, (2) overall EDC cracking depth (conversion) increase without over-cracking the furnace passes, (3) energy consumption reduction (4) unit stability improvement and (5) plant uptime increase. The application of Honeywell´s advanced solutions on LG Chem VCM II plant at Yeosu included the oxychlorination section, EDC purification section, EDC cracking section and VCM purification section. Honeywell profit controller design, practical installation experience, controller performance and results are discussed in this paper