Rules for Safe Operation of Batch Reactors

The thermal behavior of a batch reactor strongly depends on the reaction energy. The adiabatic temperature rise depends on the reactants concentration. Therefore, the charge (i.e. the amount of reactants charged) must be strictly respected. Also the quality of the reactants must be strictly controlled, since impurities may catalyse secondary reactions leading to an increase of heat release with possibly dramatic consequences. 

The reaction mass must be thermally stable in the temperature range of the process, that is, no secondary exothermal reaction must take place in the temperature range where the reactor is operated. Moreover, the reaction mass should be stable in the temperature range between Tr and MTSR. The MTSR can be calculated from Equations 5.24 and 5.26, therefore depending on the mode of initiation. 

For catalytically initiated reactions, the initial temperature that must be taken into account is the reactor temperature at the instant the catalyst is added. The accumulation is 1 at this instant. 

For thermally initiated reactions, is a function of time. Its course can be determined experimentally by measuring the thermal conversion as a function of time, while the reaction proceeds under normal operating conditions. These experiments can be carried out with DSC or, preferably with a Reaction Calorimeter. The Tcf curves can be obtained in the evaluation of the thermogram by using Equation 5.24. Its maximum (MTSR) can be searched from the TCf curve. 

If the thermal stability is not sufficient at the MTSR, emergency measures must be taken to avoid a runaway (see Chapter 10). 

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