Simple Monitoring of Fine Chemical Runaway Reactions in Multipurpose Plants: Nitration of 2,4-Dichloro Benzotrifluoride

In the fine chemical industry, new production processes are often implemented in multipurpose existing plants with minimum adaptation investments. When the new process involves a potential runaway reaction, a full thermodynamic and kinetic characterization of the system should be performed to evaluate whether the reaction can be safely scaled-up in the selected plant. However, a detailed kinetic characterization is often unsuited because of the huge development rate of new products. In this work a potential runaway reaction of the agrochemical industry, that is, the nitration of 2,4-dichloro benzotrifluoride through mixed acids, is investigated with the aim of implementing it with a minimum experimental effort in an existing plant already dedicated to a similar reaction, that is, the nitration of 4-chloro benzotrifluoride. It has been shown that, even performing very similar reactions, the ψ number criterion cannot be implemented in a univocal way to monitor the multipurpose SBR operation. Such a goal can instead be reached through the general procedure based on the ψ, X, and MTSRadset of process indicators, which was previously applied to the monitoring of polymerization processes.