Predicting thermal runaway in styrene polymerization reactions: Divergence criterion with phase space reconstruction

The process of styrene polymerization is a typical hazardous chemical process. Due to its high reaction temperature and high product viscosity, it is very prone to thermal runaway accidents. In order to reduce the occurrence of such accidents, this work investigates the thermal hazard of the polymerization process by reaction calorimetry experiments and deduces the thermal runaway criterion for the styrene polymerization reaction by combining the results of gas chromatography experiments. The phase space of the system was reconstructed by the delayed coordinate method to obtain the reconstructed divergence criterion (re-div). The results showed that the exothermic heat and adiabatic temperature rise of the polymerization reaction showed a logarithmic increase with the increase of the initial reaction temperature. Compared with the div calculated by numerical method and analytical method, the analytical method div is more accurate and effective. The analytical divergence criterion (div) curve is strictly decreasing in the post-polymerization case, which indicates that it can be used as an off-line criterion to determine the safety of the reaction process by the initial reaction condition parameters. After the experimental verification, it can be confirmed that the re-div can predict whether the reaction is out of control in advance and accurately.