Improving operability of polymerisation reactors
The POLYPROP project focused on improving the control of polyolefin properties and reactor operability in terms of reducing costs and waste. Project work involved the study of the role of particle morphology, optimisation of polymer properties, quantification of thermodynamic effects, role of phase changes during polymerisation and improvement of process operability. An important project result is the development of a software module for two- and three- dimensional and transit simulations of localised micro-mixing in fluidised bed polymerisation reactors. The software was based on Computational fluid dynamics (CFD) and Eulerian multiphase techniques for the analysis of complex fluid flows scenarios. Due to mixing and polymerisation, the software design also took into consideration mass effects as well as heat and species transfer. By exploiting advanced modelling methods, detailed descriptions over time and space are provided for a wide range of variables/parameters that are critical for polymerisation. For instance, predictions of instantaneous behaviours, such as instability effects and averaged values are easily depicted. The tool was successfully validated through comparisons of predicted results against real data obtained in industrial/pilot-scale fluidised bed reactors. Operating conditions including pressure, temperature, super-facial carrier gas velocity and duration as well as catalysts' properties and reactor's geometry affected polymer products. Apart from polymerisation, the tool may support the design and maintenance of fluidised bed reactors with other types of complex chemical processes. Partners from the computer aided process engineering alliance network are sought for possible inputs such as new industrial applications and requirements.
