A comparative study of transient flow rate steps and ramps for the efficient collection of kinetic data

Abstract

Transient cumulative flow rate varying methods have proven very effective for the collection of residence time series data for reactions in continuous flow. In this study, comparisons will be made between data collected from step changes and linear flow rate ramps, to inform method choice and minimise the complexity of automation and control needed to implement these methods, without compromising the quality of the data. Using two different analytical tools (in-line FTIR and on-line HPLC), the methods were compared in two different flow system configurations, and across three chemical reactions of increasing complexity. This work finds that the quality of the data collected using simpler step changes are comparable to that collected using more complex ramping methods, when performed in a reverse push-out (high to low flow rate) manner.