Upgrading of Total Isomerization Processes with Metal Organic Frameworks

Funder

Organizational Unit

Publications

A microporous multi‐cage metal–organic framework for an effective one‐step separation of branched alkanes feeds

Publication . Zhou, Lin; Brântuas, Pedro; Henrique, Adriano; Reinsch, Helge; Wahiduzzaman, Mohammad; Grenèche, Jean‐Marc; Rodrigues, Alírio; Silva, José A.C.; Maurin, Guillaume; Serre, Christian

The improvement of the Total Isomerization Process (TIP) for the production of high-quality gasoline with the ultimate goal of reaching a Research Octane Number (RON) higher than 92 requires the use of specific sorbents to separate pentane and hexane isomers into classes of linear, mono- and di-branched isomers. Herein we report the design of a new multi-cage microporous Fe(III)-MOF (referred to as MIP-214, MIP stands for materials of the Institute of Porous Materials of Paris) with a flu-e topology, incorporating an asymmetric heterofunctional ditopic ligand, 4-pyrazolecarboxylic acid, that exhibits an appropriate microporous structure for a thermodynamic-controlled separation of hydrocarbon isomers. This MOF produced via a direct, scalable, and mild synthesis route was proven to encompass a unique separation of C5/C6 isomers by classes of low RON over high RON alkanes with a sorption hierarchy: (n-hexane >> n-pentane approximate to 2-methylpentane>3-methylpentane)(low RON)>>(2,3-dimethylbutane approximate to i-pentane approximate to 2,2-dimethylbutane)(high RON) following the adsorption enthalpy sequence. We reveal for the first time that a single sorbent can efficiently separate such a complex mixture of high RON di-branched hexane and mono-branched pentane isomers from their low RON counterparts, which is a major achievement reported so far.

2024Journal article

Open access

Separation of branched alkanes feeds by a synergistic action of zeolite and metal-organic framework

Publication . Brântuas, Pedro; Henrique, Adriano; Wahiduzzaman, Mohammad; Wedelstedt, Alexander von; Maity, Tanmoy; Rodrigues, Alírio; Nouar, Farid; Lee, U-Hwang; Cho, Kyung Ho; Silva, José A.C.; Serre, Christian; Maurin, Guillaume

Zeolites and metal-organic frameworks (MOFs) are considered as “competitors” for new separation processes. The production of high-quality gasoline is currently achieved through the total isomerization process that separates pentane and hexane isomers while not reaching the ultimate goal of a research octane number (RON) higher than 92. This work demonstrates how a synergistic action of the zeolite 5A and the MIL-160(Al) MOF leads to a novel adsorptive process for octane upgrading of gasoline through an efficient separation of isomers. This innovative mixed-bed adsorbent strategy encompasses a thermodynamically driven separation of hexane isomers according to the degree of branching by MIL-160(Al) coupled to a steric rejection of linear isomers by the molecular sieve zeolite 5A. Their adsorptive separation ability is further evaluated under real conditions by sorption breakthrough and continuous cyclic experiments with a mixed bed of shaped adsorbents. Remarkably, at the industrially relevant temperature of 423 K, an ideal sorption hierarchy of low RON over high RON alkanes is achieved, i.e., n-hexane ≫n-pentane ≫2-methylpentane > 3-methylpentane⋙ 2,3-dimethylbutane > isopentane ≈ 2,2-dimethylbutane, together with a productivity of 1.14 mol dm−3 and a high RON of 92, which is a leap-forward compared with existing processes.

2022Journal article

Open access

3D-printed activated carbon for post-combustion CO2 capture

Publication . Zafanelli, Lucas F.A.S.; Henrique, Adriano; Steldinger, Hendryk; Díaz de Tuesta, Jose Luis; Gläsel, Jan; Rodrigues, Alírio; Gomes, Helder; Etzold, Bastian J.M.; Silva, José A.C.

The applicability of 3D-printed activated carbons for their use to CO2 capture in post-combustion streams and the influence of activation conditions on CO2 uptake and CO2 to N2 selectivity were studied. For two monoliths with the same open cellular foam geometry but low and high burnoff during activation, a series of fixed-bed breakthrough adsorption experiments under typical post-combustion conditions, in a wide range of temperature (313 and 373 K), and partial pressure of CO2 up to 120 kPa were carried out. It is shown that the higher burnoff during activation of the 3D printed carbon enhances the adsorption capacity of CO2 and N2 due to the increased specific surface area with sorption uptakes that can reach 3.17 mol/kg at 313 K and 120 kPa. Nevertheless, the lower burnoff time on monolith 1 leads to higher selectivity of CO2 over N2, up to 18 against 10 on monolith 2, considering a binary interaction to a mixture of CO2/N2 (15/85 vol%) at 313 K. The single and multicomponent adsorption equilibrium is conveniently described through the dual-site Langmuir isotherm model, while the breakthrough curves simulated using a dynamic fixed-bed adsorption linear driving force model. Working capacities for the 3D printed carbon with lower burnoff time lead to the best results, varying of 0.15–1.1 mol/kg for the regeneration temperature 300–390 K. Finally, consecutive adsorption-desorption experiments show excellent stability and regenerability for both 3D printed activated carbon monoliths and the whole study underpins the high potential of these materials for CO2 capture in post-combustion streams.

2022Journal article

Open access

Separation of n/iso-paraffins in a hierarchically structured 3D-printed porous carbon monolith

Publication . Henrique, Adriano; Zafanelli, Lucas F.A.S.; Aly, Ezzeldin; Steldinger, Hendryk; Gläsel, Jan; Rodrigues, Alírio; Etzold, Bastian J.M.; Silva, José A.C.

Hierarchically structured 3D-printed porous carbons monoliths were investigated for their applicability in adsorptive n/iso-paraffin separation. Three materials of the same macroscopic shape were employed, which varied in the micro- and mesoporosity by altering the final CO2 activation step: non-activated and activated at 1133 K for 6 and 12 h, respectively. Chromatographic breakthrough experiments were conducted for pentane and hexane isomer mixtures at industrially relevant separation conditions. Results demonstrated that the initial porosity for the non-activated monolith enables the complete separation of linear paraffins from their branched isomers (slightly adsorbed) via a near molecular sieving effect. The Langmuir isotherm conveniently fitted the adsorption equilibrium data, and a dynamic mathematical model suitably predicted the breakthrough curves. Regarding the CO2 activated monoliths, both showed adsorption towards all alkanes with practically no selectivity between them.

2023Conference object

Open access

Hexane isomers separation on an isoreticular series of microporous Zr carboxylate metal organic frameworks

Publication . Henrique, Adriano; Maity, Tanmoy; Zhao, Hengli; Brântuas, Pedro; Rodrigues, Alírio; Nouar, Farid; Ghoufi, Aziz; Maurin, Guillaume; Silva, José A.C.; Serre, Christian

A series of isoreticular Zr carboxylate MOFs, MIL-140A, B and C, exhibiting 1D microporous triangular shaped channels and based on different aromatic dicarboxylate ligands (1,4-BDC, 2,6-NDC and 4,4′-BPDC, respectively), were investigated by chromatographic breakthrough experiments regarding their ability to separate hexane isomers (nC6/2MP/3MP/23DMB/22DMB). Both single and equimolar multicomponent experiments were performed at the temperatures 343, 373, and 423 K and a total hydrocarbon pressure up to 50.0 kPa using the MIL-140B form. The elution order is similar to that of the normal boiling point of the compounds nC6 > 2MP > 3MP > 23DMB > 22DMB. It is noteworthy that this material enables separation of the hexane isomers by class, linear > mono-branched > di-branched, with a selectivity (linear + mono-branched isomers/di-branched isomers) up to 10 at 343 K, decreasing, however, as the temperature increases. Grand canonical Monte Carlo simulations were further performed to gain insight into the adsorption/separation mechanisms, highlighting the crucial need to consider a tiny tilting of the organic linkers for capturing the experimental observations. The impact of the pore size was finally assessed through the comparison with MIL-140A and MIL-140C, respectively, based on multicomponent experiments at 343 K. We evidenced a significant decrease of the selectivity (about 2) in both cases while the loadings were decreased or increased for MIL-140A and MIL-140C, respectively. Additionally, MIL-140C was demonstrated to exhibit an uncommon shift in the elution order occurring between nC6 and 3MP, 3MP being the last compound to saturate in the column.

2020Journal article

Open access