A method for maximizing the selectivity (S) of an epoxidation catalyst in an
ethylene oxide reactor system, the method comprising: receiving measured reactor selectivity (S) from an
ethylene oxide production
system. meas ), measured reactor temperature (T) meas The
ethylene oxide production
system is configured to convert a feed gas containing ethylene and
oxygen into
ethylene oxide in the presence of the epoxidation catalyst and a
chloride-containing catalyst moderator in the
ethylene oxide reactor system, along with one or more operating parameters. The epoxidation catalyst contains silver and a promoting amount of
rhenium (Re), and the reactor selectivity (S) is measured. meas The measured reactor temperature (T) meas The method also includes real-time and historical operating data points generated over time by the
ethylene oxide production
system, and the one or more operating parameters include data points generated over time by the ethylene oxide production system. The method further includes using a processor to perform the following steps: (a) for each time point, using a model to calculate the optimal moderating agent level (M) for the epoxidation catalyst. opt The model
estimation selectivity (Sest) and model
estimation temperature (Test) are considered. The model
estimation selectivity (Sest) is... est The model-estimated temperature (Test) is determined based on at least one of one or more operating parameters at the time point, the at least one operating parameter excluding the moderating agent level, and the model is based at least in part on historical
empirical data associated with the epoxidation catalyst, the ethylene oxide production system, or both. The method also includes using the processor to perform the following steps: (b) for each time point, determining the measured reactor selectivity (S). meas ) and the selectivity estimated by the model (S) est The difference (ΔS) between the measured reactor temperature (T) and the measured reactor temperature (T) meas (c) The difference (ΔT) between the temperature (Test) estimated by the model and the temperature (Test); (d) Fitting the curve to the Δselectivity (ΔS) data points as a function of the corresponding ΔT data points to obtain the fitted curve; (e) Based on the fitted curve and the real-time value of ΔS (ΔS real‑time The real-time values of ΔT and ΔT real‑time Determine the real-time relative effective moderating agent level (RCl). eff real‑time (e) based on this real-time RCL eff The method also includes using a processor to perform the following step: (f) displaying the
executable suggestion on a display.