Catalyst feed control during catalyst transition periods

摘要

Techniques are provided for operating a reactor during a catalyst transition period. The instantaneous reaction rate during a catalyst transition period can be determined using real-time measured process variables, and material balance calculations to provide an instantaneous reaction rate in approximately real time. According to certain embodiments, a material balance can be performed on the reactor system using a continuous ideal stirred tank reactor to determine the fractions of each type of catalyst that are present in the reactor, as well as the overall weight percent of catalyst in the reactor. A controller can then calculate the overall instantaneous reaction rate based on the respective catalyst fractions and the overall weight percent of catalyst in the reactor. The catalyst feed rate can then be adjusted based on the determined instantaneous reaction rate to maintain the instantaneous reaction rate within desired limits during a catalyst transition period.

主权项

1. A method of operating a reactor during a catalyst transition period, the method comprising:
feeding a first catalyst and a second catalyst to the reactor during the catalyst transition period; producing product effluent during the catalyst transition period; determining respective fractions of the first catalyst and the second catalyst in the reactor by performing a material balance on the reactor, based at least on a flow rate of the product effluent exiting the reactor; calculating an overall instantaneous reaction rate based on the respective fractions; and adjusting a feed rate for the second catalyst based on the overall instantaneous reaction rate.