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Optimal‐grade transition strategies for multistage polyolefin reactors
Author(s) -
Takeda Makoto,
Ray W. Harmon
Publication year - 1999
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690450813
Subject(s) - polyolefin , process (computing) , polymerization , sequential quadratic programming , mathematical optimization , computer science , quadratic programming , nonlinear system , state (computer science) , polymer , olefin fiber , olefin polymerization , process engineering , engineering , materials science , mathematics , algorithm , nanotechnology , physics , layer (electronics) , quantum mechanics , operating system , composite material
Polymer‐producing companies normally produce many polymer grades in each polymerization reactor train according to customer demands; therefore, many grade‐transition operations are necessary. However, the determination of these optimal strategies is difficult. To solve this problem, several sample simulations showing the optimal solutions of grade‐transition strategies for multistage olefin polymerization reactors with bimodal products were performed. The methodology utilized a dynamic process simulator, POLYRED, coupled to a sequential quadratic programming, nonlinear optimization algorithm, by using two different objective functions with and without state constraints. It is shown that the most beneficial case of using the optimization technology is the grade transition where the hydrogen content in a reactor must be decreased and/or constraints are imposed on state variables.