Continuous Emulsion Process for the Production of SBR: Computer Simulation Study for Increasing the Steady Production and for Reducing the Transients between Steady States

Abstract

The industrial production of two styrene-butadiene rubber (SBR) grades is optimized by means of arepresentative mathematical model. The emulsion process involves a train of seven continuously stirred-tankreactors. In the simulations, intermediate feeds of comonomers and chain transfer agent (CTA) are admitted.The steady-state (SS) productions can be increased by aprox 8%, while maintaining the required final values ofconversion, particle diameter, and molecular characteristics (Mh n, Mh w, and the average number of branchesper molecule). For the same rubber grade, the polymer production can be changed with negligible generationof intermediate off-specs, by regulating the global calorimetric conversion. For changes of grade at a fixedpolymer production, transient profiles of the intermediate CTA feeds are proposed. For changes of productionand grade, a sequential (rather than a simultaneous) transition seems preferable.