Semi-batch reactor operation is very common in the speciality chemicals industry. The operational goals in the chemical industry involve maximizing the productivity while meeting safety constraints. In this project, maximizing the yield of the second-order reaction (2-butanol + propionic anhydride) by manipulating the inlet flow rate is considered for an isothermal semi-batch process. Since most of the reactions are exothermic, in case of a cooling failure, a runaway situation with severe consequences may develop if no preventive measures were taken. Thus, a feed strategy is developed that allows to optimize the productivity under safety constraints, i.e. a constraint on the maximum temperature under cooling failure. Also, a constraints on the amount of heat produced is imposed for safety considerations.
The optimal solution for this case corresponds to riding on the safety constraints. For this, estimates of the heat generation and the temperature under cooling faliure are required. These are obtained using coupled spectroscopic and calorimetric sensors. The measurements are then used to update the feed rate towards optimal operation.
This project is carried out in collaboration with Novartis and the laboratory for Chemical Process Safety of the EPFL.
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Ubrich O., B. Srinivasan, P. Lerena, D. Bonvin and F. Stoessel. The Use of Calorimetry for On-Line Optimization of Isothermal Semi-Batch Reactors. Chem. Eng. Sci. , 56, 5147-5156
Srinivasan B., O. Ubrich, D. Bonvin and F. Stoessel. Optimal Feed Rate Policy for Systems with Two Reactions. IFAC Symp. DYCOPS-6, Jejudo Island, Korea (June 4-6, 2001), 455-460
Ubrich O., B. Srinivasan, F. Stoessel and D. Bonvin. Optimization of a Semi-Batch Reaction System under Safety Constraints. ECC’99, Karlsruhe, D (August-September 1999)
Ubrich O., B. Srinivasan , P. Lerena , D. Bonvin and F. Stoessel. Optimal Feed Profile for a Second-order Reaction in a Semi-batch Reactor under Safety Constraints – Experimental Study. Journal of Loss Prevention in the Process Industries, 12, 485-493