Cramer, Eike;
Ramadhan, Rafif S;
Meyer, Thomas;
(2025)
Solution for the coupled heat and mass transfer in falling film absorption using partial discretization via orthogonal collocation.
Chemical Engineering Research and Design
, 224
pp. 420-432.
10.1016/j.cherd.2025.11.031.
(In press).
Preview |
PDF
1-s2.0-S0263876225006306-main.pdf - Accepted Version Download (945kB) | Preview |
Abstract
Falling films are a key technology for highly exothermic absorption with high absorption or reaction heats. The textbook literature on falling films is typically limited to either the concentration or the temperature profiles, thereby ignoring the effects of one on the other. The literature on the coupled heat and mass transfer in falling films often relies on significant assumptions and simplifications to solve the coupled system of partial differential equations (PDEs). We derive a numerical scheme using orthogonal collocation on finite elements (OCFE) to solve the PDE system efficiently. The polynomial approximation in the OCFE scheme enables the accurate representation of gradients at the film interface, allowing us to compute accurate absorption rates even for short film lengths. We investigate cases of physical absorption with flow profiles and reactive absorption in comparison to a baseline flux balance model. Our results generally show increased absorption rates for both cases and a typical film flow length. However, a key novel insight from this work is that the absorption rate for very short film flow lengths with reactive absorption is reduced in the case of high heat of reaction.
| Type: | Article |
|---|---|
| Title: | Solution for the coupled heat and mass transfer in falling film absorption using partial discretization via orthogonal collocation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.cherd.2025.11.031 |
| Publisher version: | https://doi.org/10.1016/j.cherd.2025.11.031 |
| Language: | English |
| Additional information: | This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | Falling film absorption, Coupled partial differential equation system, Modelica, Orthogonal collocation on finite elements, Chemical falling film reactors |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10217890 |
Archive Staff Only
 |
View Item |
