Modeling of poly(phenylene oxide) reactors

Abstract

SYNOPSISA simple model is presented for the polymerization of poly(pheny1ene oxide) (PPO) in the presence of mass-transfer limitations. The mass balance and moment equations for this system compose a hierarchy of infinite ordinary differential equations. Closure conditions similar to those used for nylon 6 are used to truncate the set of moment equations. The rate constants are adjusted to achieve a reasonable fit between model predictions and one set of available experimental data on the variation of the number-average chain length (pn) with time. The monomer conversion and the polydispersity index (PDI) are predicted. The PDI of the entire macromolecular species is found to vary with time in an interesting manner (a decrease is predicted with time during certain periods). This is due to the effect of mixing of two sets of macromolecular species present in the reaction mass having different concentrations, as well as different individual values of p n and PDI. Sensitivity results are reported to identify the important parameters and operating conditions. It is found that the values of pn are very sensitive to even small changes in the operating conditions which decrease the mass-transfer rates. 0 1995 John Wiley & Sons, Inc.

Microreactor technology and process miniaturization for catalytic reactions—A perspective on recent developments and emerging technologies

“…Multiphase reactions that are catalyzed by homogeneous organometallic complexes (Behr, 2005;Cornils et al, 2005), heterogeneous solid catalysts (Knozinger and Kochoefl, 2005), or various types of biocatalysts (Aehle, 2003;Liese and Lütz, 2004;Prenosil et al, 2005) provide the basis for most of the commercial-scale processes used to manufacture petroleumderived products (Irion and Neuwirth, 2007), commodity and fine chemicals (Cheng and Ko, 2004), pharmaceuticals (Bader, 1994;Rasor and Voss, 2001), and certain high performance engineering polymers, such as aromatic polycarbonates (Serini, 2000) and polyphenylene oxide (Misra and Gupta, 1995). A review of recent developments in catalysts and catalytic process technology suggests that significant market growth is occurring across a variety of multiphase reaction platforms (Comyns, 2007).…”

Scale-up and multiphase reaction engineering

“…Multiphase chemistries involving reactions between gases, liquids, and solid reactants that are catalyzed by homogeneous organometallic complexes [2], heterogeneous inorganic solids [3] or biocatalysts [4][5][6] are the basis for nearly all processes used to manufacture organic and inorganic intermediates and end-use products, such as fuels and chemicals from petroleum feed-stocks [7], bulk commodity, specialty and fine chemicals [8], medicinal intermediates and pharmaceuticals [9,10], and various polymers [11][12][13]. End-of-pipe processes for environmental remediation also rely upon multiphase catalyzed chemistries for emissions control [14][15][16].…”