Yokogawa has contributed to the success of a multivariable application based on EXASMOC (multivariable optimizing controller) for the units used around a steam cracker.

Shell Berre is a Petrochemical complex located at Berre near Marseille, France. The activities are focussed around the chemical product derivated from oil (solvents, polymer, polyolefine, etc.). The EXASMOC package is used for the control and the optimization of equipment such as separation/purification columns and compressor.

Five multivariable control applications are implemented on the main columns of the cracked gas separation section (deethanizer, ethane, ethylene splitter, depropanizer, debutanizer, propane/propylene splitter). Further an economic optimisation application is also implemented on the propylene cold cycle compressor.

Four applications are implemented on the HDT unit (separation section of the pyrolysis gasoline's with hydrogenation of the C5 and C6 cuts), depentanizer, dehexanizer, propane/ propylene solvent grade stabilizer and one to maximize the global throughput of the unit within its constraints.

Shell chemical appreciate Yokogawa as partner of APC solution provider since Yokogawa established long good relationship.

The EXASMOC applications on columns control mainly the top and bottom product quality based on set points, constraints and economic objectives of maximization and minimization. EXASMOC package control the process through a CENTUM CS 3000 and three CENTUM-XL all connected on the same Vnet control bus. The earnings brought by the EXASMOC applications are around 1.3 M euro / year.