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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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≈2‐methylpentane>3‐methylpentane)low RON≫(2,3‐dimethylbutane≈i‐pentane≈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. [ABSTRACT FROM AUTHOR]

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≈2‐methylpentane>3‐methylpentane)low RON≫(2,3‐dimethylbutane≈i‐pentane≈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. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D-printed carbon-based monoliths were studied in adsorptive alkane isomer separation. • Fixed bed breakthrough experiments were conducted for C5/C6 isomer feed mixtures. • The pristine monolith shows a near molecular sieving effect for the branched alkanes. • The CO 2 -activated monoliths significantly adsorbed all the alkane isomers. • A dynamic fixed bed adsorption model is developed to simulate the experimental data. 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 CO 2 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 CO 2 -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 CO 2 activation. The breakthrough data for the non-activated monolith is also numerically fitted with a convenient, dynamic adsorption model. [ABSTRACT FROM AUTHOR]

The adsorption equilibrium and kinetics of CO2, CH4, and N2 on three types of BETA zeolites were investigated at different temperatures and a defined partial pressure range from dynamic breakthrough experiments. The adsorbed amount followed the decreasing order of CO2 > CH4 > N2 for all studied materials. For the same ratio of SiO2/Al2O3, the Na‐BETA‐25 zeolite showed a higher uptake capacity than H‐BETA‐25, due to the presence of a Na+ cationic center. Comparing the same H+ compensation cation, zeolite H‐BETA‐25 expressed a slightly higher adsorption capacity than H‐BETA‐150. Regarding the selectivity of gases, based on their affinity constants, H‐BETA‐150 displayed the best ability. The adsorption kinetics was considered using the zero‐length‐column (ZLC) technique. Response surface methodology (RSM) was applied to evaluate the interactions between adsorption parameters and to describe the process. Natural gas upgrading requires adsorption of CO2, CH4, and N2. Three different types of BETA zeolites were tested regarding the adsorption equilibrium for these gases. Their structure can be easily functionalized in terms of cation exchange and hydrophobicity index by the SiO2/Al2O3 ratio. Langmuir isotherm and response surface methodology were employed for modeling and statistical analysis. [ABSTRACT FROM AUTHOR]

The applicability of 3D-printed activated carbons for their use to CO 2 capture in post-combustion streams and the influence of activation conditions on CO 2 uptake and CO 2 to N 2 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 CO 2 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 CO 2 and N 2 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 CO 2 over N 2 , up to 18 against 10 on monolith 2, considering a binary interaction to a mixture of CO 2 /N 2 (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 CO 2 capture in post-combustion streams. [Display omitted] • Printed activated carbon monoliths were developed as adsorbents for CO 2 capture. • Thermal treatment affects the selectivity of CO 2 over N 2 on the monoliths. • CO 2 working capacity on the monolith M1 is 17% higher than monolith M2. • 3D-printed monoliths show high stability and regenerability over consecutive cycles. • A mathematical model has been developed for process simulation to CO 2 capture. [ABSTRACT FROM AUTHOR]

• The adsorption dynamics of C5/C6 isomers in ZIF-8 is evaluated in a fixed bed. • Adsorption equilibrium isotherms for linear nC5 and nC6 were measured. • A complete separation between linear nC5 and nC6 and branched isomers is observed. • The sorption of linear paraffins nC5 and nC6 is dominated by equilibrium. • The sorption of branched isomers is essentially kinetically driven. Single, quinary and septenary fixed bed breakthrough experiments of pentane (nC5/iC5) and hexane (nC6/2MP/3MP/23DMB/22DMB) isomers were performed in shaped zeolitic imidazolate metal organic framework ZIF-8. Adsorption equilibrium isotherms for linear nC5 and nC6 were measured from the single component breakthrough curves covering the temperature range between 373 and 473 K and partial pressures up to 50 kPa. The equimolar septenary (nC5/iC5/nC6/2MP/3MP/23DMB/22DMB) and quinary (iC5/2MP/3MP/23DMB/22DMB) studies were performed at the same temperature range and total hydrocarbon pressure of 25 kPa. In the septenary experiments the following sorption hierarchy was observed: nC6 > nC5 > 2MP > 3MP > iC5 > 23DMB > 22DMB. Results also show that the sorption of the linear nC5 and nC6 is dominated by equilibrium in contrast with the sorption of branched isomers which is kinetically controlled. The quinary experiments with C5/C6 branched paraffins evidences the partially separation by classes of mono- and di-branched isomers. The equilibrium data were modelled by the Sips isotherm and the fitted parameters were used to simulate the breakthrough data through a mathematical model developed in a Matlab code using the method of lines (MOL). In the numerical simulations equal diffusivities constants (D c /r c 2) for linear nC5/nC6 were used, being it 0.002 s−1 at 373 K, which is a value 100 times higher than its respective value for the mono-branched isomers iC5, 2MP and 3MP, and 300 times higher than for the di-branched hexane isomer 22DMB. It is also shown the effect of the residence time of the gas regarding the fixed bed separation of the pentane and hexane isomers, from where it is clear that increasing the residence time improves the separation between the compounds. [ABSTRACT FROM AUTHOR]