Early warning monitoring of exothermic batch reactions: A kinetic-free approach

In the multipurpose fine chemical industry, several performance goods are produced in the same plant at relatively low volumes: the reactor is therefore typically operated on a discontinuous campaign basis. Moreover, if the reaction is not excessively fast and exothermic, the process is often performed in the simple batch mode, according to which all the raw materials are initially loaded into the reactor and the reaction is then triggered. The monitoring of the safe operation of a batch reactor is therefore even more critical than that of a fed-batch one, because all the reactants are in contact since from the beginning. In this work a kinetic-free approach is presented, through which the quasi-adiabatic unsafe operation of a batch reactor can be early detected before an excessive temperature peak, where an incidental scenario could occur: this allows for preventively adopting emergency actions aimed for example to quench the system or to bottom relieve the reaction mass. The proposed criterion has been validated through some industrial data of a potentially runaway reaction of the fine chemical industry, that is, the solvent-based batch polymerization of acrylic acid.