Separation of alkane isomers in a hierarchically structured 3D-printed porous carbon monolith

Henrique A, Steldinger H, de Tuesta JL, Gläsel J, Rodrigues AE, Gomes HT, Etzold BJ, Silva JA (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Chemical Engineering Journal Elsevier

Book Volume: 472

Article Number: 145138

DOI: 10.1016/j.cej.2023.145138

Abstract

Hierarchically structured 3D printed porous carbons monoliths, exhibiting cylinder structures composed of tetragonal cubic centered unit cells, were studied for their applicability in adsorptive pentane (C5) and hexane (C6) alkane isomers separation (linear/branched). Three materials of the same macroscopic shape were employed in the study, which varied in the micro- and mesoporosity by changing the final CO2 activation step: non-activated and activated at 1133 K for 6 and 12 h, respectively. Fixed bed breakthrough experiments were conducted for C5/C6 isomer feed mixtures, covering 373, 423, and 473 K temperatures and total alkane partial pressure up to 50.0 kPa. Results demonstrated that the initial porosity for the non-activated monolith enables the complete separation of linear from their respective branched isomers (slightly adsorbed) via a near molecular sieving effect, showing the following sorption hierarchy order (nC6 > nC5) ≫>≫ (2MP > 3MP > 23DMB ≈ iC5 > 22DMB). Regarding the CO2-activated monoliths, both showed a completely different picture, being all the alkane isomers adsorbed (much higher loadings) following the sorption hierarchy order: nC6 > 3MP > 2MP > 23DMB > 22DMB > nC5 > iC5. These results indicate that besides enhancing the microporosity and available specific surface area, the pore sieving effect of branched alkanes is lost due to the pore widening during the CO2 activation. The breakthrough data for the non-activated monolith is also numerically fitted with a convenient, dynamic adsorption model.

Authors with CRIS profile

Bastian Etzold

Involved external institutions

Polytechnic Institute of Bragança / Instituto Politécnico de Bragança (IPB) PT Portugal (PT) Technische Universität Darmstadt DE Germany (DE) Universidade do Porto PT Portugal (PT)

How to cite

APA:

Henrique, A., Steldinger, H., de Tuesta, J.L., Gläsel, J., Rodrigues, A.E., Gomes, H.T.,... Silva, J.A. (2023). Separation of alkane isomers in a hierarchically structured 3D-printed porous carbon monolith. Chemical Engineering Journal, 472. https://dx.doi.org/10.1016/j.cej.2023.145138

MLA:

Henrique, Adriano, et al. "Separation of alkane isomers in a hierarchically structured 3D-printed porous carbon monolith." Chemical Engineering Journal 472 (2023).

BibTeX: Download