Automated detection of loading and flooding points in packed columns

Predictive correlations for packed distillation and absorption columns usually cannot account for changes in operating limits due to phenomena such as fouling. A method for detection of loading and flooding points even under altered operating conditions would therefore be highly desirable. In this work, a new approach for real-time detection of packed column loading and flooding points is introduced. The method utilises Fourier analysis of pressure drop data. Pressure drop fluctuations occurring even under steady-state conditions are sampled and treated with Fast Fourier transform (FFT) to derive the corresponding frequency spectra. Results of examinations with three structured packings (RSP 250Y, RMP N 250X, RMP N 250Y) conducted at three liquid loads each show that operating regions (below loading point, loading point, loading region, flooding point) can be identified from the obtained frequency spectra. Starting at the loading point, certain amplitudes within the spectra grow and increase up to the flooding point. This behavior is consistent for all examined packings. The results from this study suggest that the pro-posed approach could support column operation as an additional monitoring tool that is low in cost and not reliant on additional measurements besides pressure drop.& COPY; 2023 The Authors. Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY license (http://creative-commons.org/licenses/by/4.0/).