Chemical Microreactors For In-Situ Online Process Monitoring

Chemical reactions can be very complex and frequently produce undesired side products within short time spans. Investigation of such reactions necessitates in-situ measurements for analysis. We present a novel micro-reactor design enabling non-invasive and spatially highly resolved in-situ reaction analysis using Raman spectroscopy. The reactor consists of a stainless steel base containing milled channels covered with anodically bonded pyrex glass. The educt flow rate is finely controlled by a motor-driven feed pump. Monitoring of an exemplary test reaction by Raman spectroscopic means was achieved by recording spectra at various discrete sampling points along the reaction channel. The glass window allows visual observation of the channels by optical microscopy and does not affect, in contrast to infrared spectroscopy, the Raman spectroscopic signal. Taking Raman spectra along the reaction channel at different loci enabled us to determine the reaction kinetics of a fast chemical reaction.