Safe optimization of potentially runaway reactions: From fedbatch to continuous stirred tank type reactor

Abstract

A great variety of processes of both fine chemical and pharmaceutical industries are commonly carried out in semibatch reactors (SBRs). Most of such synthesises often involve strongly exothermic and very fast reactions where the control of the heat evolution is achieved thanks to the combined effect of a dedicated cooling system and the feeding of a "cold" (mostly, ambient temperature) co-reactant. For these types of process, the well known phenomenon of "thermal runaway" can take place. Accordingly to the ever increasing market requests, the desired goal of whatever enterprise is to increase the productivity of a certain product being sure of maintaining safe operating conditions during all the synthesis steps. This is a very hard task which can be performed by changing the reactor operating mode from semibatch to continuous. A continuous reactor can achieve the same productivity of a discontinuous reactor using significantly lower reaction volumes; this means that the intrinsic safety of the process is increased. In this work, the switch from a semibatch reactor to a series of continuous stirred tank reactors has been investigated using as a case study the nitration of N-(2-Phenoxyphenyl) methane sulphonamide. Particularly, after the determination of the most effective number of reactors in the series and their effective volumes, dynamical simulations have been carried out in order to guarantee that possible thermal instabilities are not generated during the synthesis in both the start up and the normal exercise phases.

Investigation on dynamic VOC production from industrial, high solids content emulsion polymerizations

“…However, with the constant increase by the different stakeholders involved in safer and healthier processes 9 and goods, regulations are becoming lesser and less loose on the amount of VOCs in commercial goods 10 , demanding for new technologies to keep up with the more strict requirements.…”

Continuous flow synthesis of N,O-dimethyl-N'-nitroisourea monitored by inline FTIR: comparing machine learning and kinetic modeling for optimization

“…[1][2][3][4][5] Traditional methods using batch reactors often struggle with inconsistent reaction conditions and potential safety risks. 6 Continuous flow microreactors have been recognized for their superior mixing efficiency 7,8 , precise control over reaction parameters 9 , and safety benefits [10][11][12][13] , showing potential for improving reaction selectivity [14][15][16][17] . However, their application in synthesizing these specific intermediates remains unexplored.…”

Continuous Flow Synthesis of N,O-Dimethyl-N′-nitroisourea Monitored by Inline Fourier Transform Infrared Spectroscopy: Bayesian Optimization and Kinetic Modeling

“…They are known for their rapid killing of pests and long-lasting control and are widely used in agriculture, horticulture, forests, and other fields with a high production application value − Traditional batch synthesis of these intermediates often struggles with inconsistent reaction conditions, potential safety risks, and long reaction times . In contrast, continuous flow microreactors have been recognized for their superior mixing efficiency, , precise control over reaction parameters, and safety benefits, − showing potential for improving reaction selectivity. − However, their application in synthesizing these specific intermediates remains unexplored.…”