Online IR spectroscopic quantification and reaction process analysis in continuous flow system

Continuous flow is widely used in chemical synthesis owing to its superior reaction control and high heat/mass transfer efficiency. However, current component concentration quantification techniques, including online instruments, still require extensive offline experiments to establish quantification models for each reaction system, which limits the analytical efficiency of continuous flow reactions. In this work, a quantitative analysis method for continuous flow reaction systems is established using online FTIR spectroscopy combined with dynamic flow rate control. A quantification model is constructed with artificial neural networks from the sampled infrared spectroscopic data generated by continuously adjusting flow rates, and is utilized to monitor reactions and predict reactant and product concentrations in real time. Additionally, kinetic analysis and reaction condition optimization are performed via continuous flow experiments under varying flow rates. Results demonstrate that this method enables rapid and continuous quantitative analysis of continuous flow reactions, offering an effective approach for reaction monitoring and process optimization.