A model for the devolatilization of EPDM rubber in a series of steam stripping vessels

Abstract

A mathematical model was developed for the multitank stripping section of industrial ethylene propylene diene monomer (EPDM) rubber processes. Experiments were conducted to determine Henry's law coefficients and diffusivities for hexane solvent and 5-ethylidene-2-norbornene (ENB) comonomer in EPDM particles. Equivalent radii for diffusion within the particles were also determined. A model was developed to predict solvent and comonomer concentrations in a single particle as it moves through a series of tanks with different operating conditions. A second, more-complicated model was then developed to account for a continuous flow stirred tank residence time distribution for the particles in the tanks. Data from three industrial plants were used to estimate parameters and assess the models' predictive ability. Typical prediction errors are 0.90 wt % for residual hexane and 0.14 wt % for residual ENB.

Modelling Sorption Thermodynamics and Mass Transport of n-Hexane in a Propylene-Ethylene Elastomer

“…Very few data are available in the literature to be compared with our results for sorption isotherms of n-hexane in polymer systems similar to the one under investigation. In particular, Francouer [ 38 ] reports results for n-hexane sorption in EPDM (i.e., terpolymers composed of ethylene, propylene, and various diene monomers). These data were collected in the 90–140 °C interval, although the exact temperatures at which data were collected are not specified for proprietary reasons, indicating simply T1 for highest temperature investigated and T5 for the lowest.…”

“…In particular, data are available in the literature for n-hexane diffusion in EPDM [ 38 ]. These data were collected in the 90–140 °C interval, although the exact temperatures are not specified for proprietary reasons, indicating simply T1 for highest temperature investigated in that range and T5 for the lowest.…”

Dynamic Analysis Model for the Diffusion Coefficient in High-Viscosity Polymer Solution

“…Gravimetric analysis is another common method. Francoeur 20 measured the average diffusion coefficient of solvent hexane and monomer 5-ethylidene-2-norbornadiene (ENB) in ethylene−propylene−diene monomer (EPDM) by gravimetric analysis, and the diffusion coefficient was used in a mass transfer model in describing a continuous flow stirred tanks.…”

“…where C is the mass concentration (g/g) of the volatile solvent in the polymer, D AB is the mutual diffusion coefficient of volatile component and polymer, L (m) is the thickness of the liquid sheet, t (s) is the time of diffusion, and x (m) is the vertical coordinate in liquid sheet. Equation 4 was resolved to the integral formula eq 5, and an average diffusion coefficient of volatiles D AB in the diffusion process can be calculated by this equation in the literature: 20,21…”

Experimental Studies and Modeling of Devolatilization of Highly Viscous Solution in High-Speed Disperser

“…In general, these volatiles can adversely affect the physical/ chemical properties and application performance of polymers. The removal of residual volatiles from polymers is necessary and is usually achieved by a process called polymer devolatilization (Tukachinsky et al, 1993) to ensure the quality of the polymer products, meet environmental requirements (Francoeur et al, 2014), and eliminate health hazards.…”