Dynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation by using inlet glass fibers injection response and application to polymers degassing

International audienceIn this paper is described an original dynamic model of a reactive co-rotating twinscrew extrusion (TSE) process operated by the Rhodia company for the Nylon-66 degassing finishing step. In order to validate the model, dynamic experiments have been performed on a small-scale pilot plant. These experiments consist in a temporary injection of glass fibers at the inlet of the extruder after it has reached a given operating point. The outlet glass fibers mass fraction time variation is then measured. This experiment does not lead to the RTD measurement. As a matter of fact, due to the high quantity of glass fibers that is introduced, the behavior of the flow through the extruder is perturbed so that the glass fibers cannot be considered as an inert tracer. The dynamic model that we have published elsewhere (Choulak et al., Ind. Eng. Chem. Res., 2004, 43(23), 7373-7382) is adapted to take into account this nonlinear behavior of the extruder with respect to the glass fibers injection and is favorably compared to experimental results. The description of the degassing operation is also included in the model. The model allows simulations of the complete dynamic behavior of the process. When the steady state is reached, the good position of the degassing vent with respect to the partially and fully filled zones positions can also be checked, thus illustrating the way the model can be used for design purposes

Contribution of reactive extrusion to technological and scientific challenges of eco-friendly circular economy

Nowadays, development and production in eco-friendly circular economy are themes of great importance. Concerning optimization of materials production, reactive extrusion (REX) is well established, using extruder as a chemical reactor. Biopolymers and recycling are two interesting fields in which REX can be used. In fact, through REX, biopolymers can be produced from monomers, modified (grafting…) or chemically blended with other polymers. Moreover, chemical reactions can occur between polymers and additives in order to optimize post-consumer polymer recycling. The first part of this chapter will focus on REX modellization, useful to optimize REX parameters, in agreement with eco-friendly circular economy domain. The second part of this chapter will focus on the production process of bio-derived polymers, their blends and composites, as well as recycling of post-consumer polymers