Multicomponent flash algorithm for mixtures containing polydisperse polymers

Phase equilibria in polydisperse and associating copolymer solutions: Poly(ethene-co-(meth)acrylic acid)–monomer mixtures

“…The summation over all association-site types A iα is independent of the number of pseudo-components because the association energy parameter is assumed to be the same for all association sites. As a new variable, the mean associationsite numberN i for copolymer i, which is analogous to the mean segment number [19], is introduced:…”

“…As described by Tork et al [20], these pseudo-components are generated such as to match the moments of the molecular weight distribution. The pseudo-component concept has already been applied in conjunction with considering hard-chain contributions and with treating the dispersion term of the SAFT-type equations of state by Gross [21], Jog and Chapman [18] and Behme et al [19]. In Section 3.2, two approaches of applying the concept of pseudo-components to the association term within PC-SAFT are described.…”

“…The complexity of the system of equations drastically increases with the number of pseudo-components, which restricts this approach to systems with a very few such components. In case that a large number of pseudo-components needs to be considered, an alternative approach should be used which is similar to the one presented in the earlier work of Behme et al [19]. This latter approach allows for calculations without increasing computational complexity.…”

“…To account for copolymer polydispersity, the concept of pseudo-components has been applied [15][16][17][18][19]. As described by Tork et al [20], these pseudo-components are generated such as to match the moments of the molecular weight distribution.…”

Industrial perspective

“…After the feed polymer phase separates, the molecular weight distribution of polymer in the light phase will be different from that in the heavy phase. Recently, Behme (2003) introduced an efficient algorithm for solving two-phase (VL and LL) phase equilibrium calculations for polymer systems with molecular weight distribution. Research is on-going to enhance robustness of the algorithm.…”