Integration of Microreactors with Spectroscopic Detection for Online Reaction Monitoring and Catalyst Characterization

Abstract

Microreactor technology has gained significant popularity in the chemical and process industry in the past decade. The development of microreactors either as innovative production units for chemical synthesis or as promising laboratory tools for reaction and kinetic studies relies highly on the capability of performing online analyses, which opens great opportunities for the integration of spectroscopic detection techniques. This paper gives an overview of the state-of-the-art in the combination of microreactors with spectroscopic analyses for online reaction monitoring and catalyst characterization. In this upcoming field, many studies have been carried out combining fluorescence, ultraviolet−visible, infrared, Raman, X-ray, and nuclear magnetic resonance spectroscopy. Current research progress is reviewed, with emphasis on the existing integration schemes and selected application examples that demonstrate the potential of online spectroscopic detection for rapid microreactor process analysis and optimization. An outlook on the future development in this area is also presented.

Design and additive manufacture for flow chemistry

“…It is important to be able to monitor the output of each unit within the chain, to identify faulty units, or variable outputs during the process. 101 In line analysis also allows precise control over reaction Fluorescence spectroscopy has gained wide-spread use in µTAS due to its high sensitivity to the small detection volumes used in microfluidic devices. 104 It is based on the detection of light emission from excited singlet states of fluorescent substances (fluorophores).…”

“…This type of spectroscopy also has significant applications in the analysis of biochemically important materials such as amino acids, which can be readily IR spectroscopy is the measurement of absorption or emission of electromagnetic radiation in the IR region as a consequence of vibration within a molecule. 101 FTIR is an effective method for determining chemical structures, functional group conversions, and product concentrations. Consequently, FTIR has been implemented into µTAS for a variety of applications.…”

Beyond Organometallic Flow Chemistry: The Principles Behind the Use of Continuous-Flow Reactors for Synthesis

“…126 Inline spectroscopical detection systems can be combined with microreactor technology and maximizes the information content of each experiment. 127 One of the major advantages of batch kinetics is that it allows to generate a lot of data in a single experiment by collecting several data points over time. Time-series data can be obtained in microflow reactors by using a controlled ramp of the flow rate and inline analysis methods.…”

Síntese Em Sistemas Microfluídicos De Nanopartículas De Cdte E De Ag Para Estudo Qualitativo De Interação Em Fluxo E Preparação De Filmes Finos Desses Nanomateriais

“…A integração online aos sistemas microfluídicos de técnicas de análise química instrumental cromatográfica (MA et al, 2009), eletroquímica (LIN et al, 2015 e espectroscópica (WANG, N. et al, 2016) permite o controle direto do processo sintético, possibilitando a automatização e otimização da reação (KRISHNAN et al, 2001;WAGNER e KÖHLER, 2005;DITTRICH e MANZ, 2006;HARTMAN e JENSEN, 2009;YUE et al, 2012;COUTO et al, 2015;MACEICZYK et al, 2015) As vantagens da TMR integrada às técnicas de monitoramento em tempo real permitem o controle preciso das condições do processo, com uma taxa de fluxo bem definida, mistura eficiente, distribuição de temperatura uniforme e operação segura em uma ampla janela de processo. Além disso, torna-se um meio atraente para a extração de informações cinéticas e rápida aquisição de dados (TAKAHASHI et al, 2007;SWAIN et al, 2017).…”

“…O monitoramento online da reação pode revelar a presença de espécies de curta duração ou intermediários instáveis que podem não ser observados através de análise off-line (YUE et al, 2012). Um dispositivo em fluxo contínuo com monitoramento online permite o controle das variáveis (concentração, volume, temperatura e pressão) durante o processo reacional, corrigindo-as, caso seja necessário, de maneira segura e inteligente (KRISHNADASAN et al, 2004 et al, 2015).…”