Control of Hazardous Processes in Flow: Synthesis of 2-Nitroethanol

Abstract

After a short section of safety aspects related to 2-nitroethanol, the paper describes a powerful methodology for developing flow processes based on a proof of concept (1), an optimization and modeling analysis (2), and a long run study in a mini-plant (3). The proof of concept is the initial stage where the solubilities and concentrations are fixed, taking into account the rough kinetics with a mass transfer understanding. It is followed by a complete kinetic analysis including activation energy to model the reaction under various conditions to optimize different targets (yield not being the only driver!). The last section shows the operation of a mini-plant including a microreactor and work-up unit operations. The approach is extremely powerful as it enables the study at laboratory scale of all the features that are usually associated with a pilot plant namely: stability over time on stream, solvent recirculation, model prediction, and robustness.

Chemical reaction engineering, process design and scale-up issues at the frontier of synthesis: Flow chemistry

“…Similar concepts were applied by the same authors to a full platform of organic reactions carried out under cryogenic conditions [148]. Finally, an example of Grignard reaction in microreactors confirm that it is possible to effectively control the hot spot [149].…”

5. From batch to continuous chemical synthesis – a toolbox approach

“…The CSTR flow pattern is quite useful when the reaction is very fast and the selectivity is not negatively influenced by the mixed flow regime, such as for acid-base precipitations [46]. A CSTR is a pragmatic approach to overcome the problem associated with solids handling, but its mixed flow pattern has inherent disadvantages relative to the near plug flow pattern that can be achieved in the Coil and Plate reactors.…”

Continuous Downstream Processing of Amino Acids in a Modular Miniplant

“…Moreover, process safety can be inherently increased when handling small amounts of hazardous chemicals at one point of time in a continuous-mode production campaign, compared with a batch production campaign of equal capacity [7,8]. Various research groups from both industry and academia recently demonstrated the applicability of continuous production concepts for fine chemicals and pharmaceuticals in dedicated examples [9][10][11][12][13][14][15][16].…”