Abstract: This invention describes a new process for monitoring and regulation of an industrial unit that comprises a closed-loop identification phase for the parameters of a model of said industrial unit, implemented in a multi-variable, predictive linear monitor, whereby said identification phase is implemented in a closed loop, which makes it possible to minimize the substandard production of said unit.

Abstract: Method of optimizing the operation of a unit intended for separation of the components of a feed (xylenes) by simulated countercurrent in hybrid operating mode. The method allows to minimize the solvent ratio and to maximize the capacity of the separation unit while keeping product specifications such as purity and yield constant. It has been verified that these two objectives cannot be reached simultaneously and it is recommended to operate with a minimum solvent ratio while guaranteeing a high capacity compatible with stable operation of the separation unit. These optimization objectives are reached while keeping good stability around the optimum point thus defined, by using a known operation control process such as the one described in patent EP-875,268 for example.

Abstract: Method of optimizing the operation of a unit intended for separation of the components of a feed (xylenes) by simulated countercurrent in hybrid operating mode. The method allows to minimize the solvent ratio and to maximize the capacity of the separation unit while keeping product specifications such as purity and yield constant. It has been verified that these two objectives cannot be reached simultaneously and it is recommended to operate with a minimum solvent ratio while guaranteeing a high capacity compatible with stable operation of the separation unit. These optimization objectives are reached while keeping good stability around the optimum point thus defined, by using a known operation control process such as the one described in patent EP-875,268 for example.

Abstract: Method for controlling with precision a permanent in-line process for separating constituents of a mixture in a simulated moving bed separation system from concentration and flow rate measurements.The system comprises a set of columns forming a closed loop comprising several zones between fluid injection and draw-off points. Control of the process (linear or nonlinear) is performed from a knowledge model and from a certain number of operating variables at a plurality of measuring points along the loop (concentrations and flow rates for example) and characteristic measurements of the fluids injected and drawn off. Ratios respectively indicative of the ratio, in each of the different zones, between the fluid flow rates and the simulated adsorbent material flow rates, are determined from actual values of controlled variables depending on the measured operating variables (purity of the constituents, system yield, etc.).

Abstract: In a simulated mobile bed separation process, perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) or compressor for a liquid, supercritical or gaseous mixture in a closed circuit of columns.

Abstract: In a simulated mobile bed separation process, perturbations are corrected in the compositions of an extract (EA) or raffinate (RB) due to the dead volume introduced by at least one recycling pump (P) or compressor for a liquid, supercritical or gaseous mixture in a closed circuit of column sections. The volume of the section immediately upstream of the dead volume is reduced by an appropriate value when said dead volume is located downstream of this section and upstream of the extraction streams of said section, or the volume of the section immediately downstream of the dead volume is reduced by an appropriate value when the dead volume is located downstream of the injection streams into said section and upstream of this section.The invention is applicable to the separation of isomers of aromatic hydrocarbons containing 8 carbon atoms.