Separation Of Mixtures Research Articles

Solid–solid thermal synthesis of bimetallic Ni/Zn embedded in N-doped porous carbon for efficient adsorptive separation based on CO2 adsorption at low pressure

High-efficient adsorptive materials for carbon dioxide (CO2) capture and separation of a gas mixture are vital for energy consumption and emission reduction but are still a substantial challenge. A facile synthesis of bimetallic nickel/zinc embedded in N-doped carbon (Ni/Zn@NC) through the solid–solid thermal method (SST) is developed herein. The SST method is a straightforward procedure with the advantage that the materials are obtained in a single step and solvent-free conditions. Thermal analysis and material characterization were used to investigate the synthesis mechanism during the SST process. The results revealed that an intermediate material, initially obtained at a low thermal temperature, was sacrificed to generate Ni/Zn@NC at high temperatures of the SST method. The resulting robust carbon structure, decorated with heteroatoms (Ni, Zn, N), exhibits a potential for efficient CO2 adsorption during the capture and separation of biogas (CO2/CH4), off-gas (CO2/N2), and natural gas (CH4/ N2). The synergetic effect of Ni in the materials enhances the selectivity of SCO2/CH4, SCO2/N2, and SCH4/N2. The improved selectivities by effective sites were confirmed by computational modeling. Significantly, the Ni/Zn@NC material obtained through a mild yet simple synthesis method (SST) exhibits substantially higher CO2 adsorption capacity and selectivity when compared to commercial carbon (activated charcoal).

Separation of VOC Gaseous Mixtures Using an Adsorption–Desorption Device

The aim of this work was to separate ethanol in an experimental adsorption–desorption device. We focused on concentrating ethanol by adsorption onto granulated activated carbon in its gaseous phase, which was produced by stripping a matrix with different ethanol concentrations (2, 5, 10, and 15% v/v). For adsorption, three kinds of granulated activated carbon (GAC) were used, marked as GAC1, GAC2, and GAC3. The separation product had a higher ethanol concentration than the initial ethanol concentration before the adsorption–desorption process. The enrichment factor was, in the case of the initial ethanol concentration, 2% v/v at the level of 10. With our new adsorption–desorption device, it is possible to achieve a product with an ethanol concentration of 59.0% v/v with stripping, adsorption, desorption, and condensation. To verify the separation efficiency, a real matrix (fermentation broth) was used. The ethanol concentration in the real matrix was, at the beginning of the separation process, 0.65% v/v; after using our separation device, it was 11.35% v/v. Using a real matrix, the enrichment factor was at the level of 18. The main advantage is the use of our new adsorption–desorption device for the continuous separation of ethanol from fermentation broth. A mathematical model was created, based on which it is possible to calculate the ethanol concentration in the product of the separation process with high accuracy.

Electrochemically Modulated Separation of Olefin-Paraffin Gas Mixtures in Membrane Electrode Assemblies

Olefin-Paraffin separations are ubiquitous chemical processes used in purifying monomers for the manufacture of a large variety of polymers and chemical intermediates. Some of the highly demanded olefin-made products include polyethylene, ethylene oxide, vinyl acetate, polypropylene, acrylonitrile, propylene oxide, and acrylic acid. Olefin-paraffin mixtures are relatively difficult to separate because of the similarity in physical properties of each component. Currently, olefins are typically purified via cryogenic distillations, a highly energy-intensive process that liquifies the hydrocarbon gas mixture and re-vaporizes them repeatedly, requiring approximately 3.6 MJ per kg of olefin purified. Because of the large energy-intensive of the process, olefin separations are responsible for approximately 0.3% of the global energy consumption, to produce 200 and 130 million metric tons per year of ethylene and propylene respectively (2020).Alternative non-thermal olefin-paraffin separation methods have the potential to increase the efficiency of this separation, and thus increase its sustainability. In this presentation we will discuss an alternative separation method based on an electrochemically modulated swing absorption system. In this system, Nickel(II) maleonitriledithiolate, an electrochemically active organometallic complex, is dispersed in an ionogel and integrated in a membrane electrode assembly (MEA). The oxidation state of Nickel(II) maleonitriledithiolate can be electrochemically modulated based on potential. At its oxidized state [i.e., Ni (IV)], the complex has a strong affinity towards the olefin’s pi-bond, while at its reduced state [i.e., Ni (II)] the complex loses this affinity. Our results show that when exposed to propylene-propane gas mixtures, propylene was selectively captured by the organometallic species during oxidative phase, and then released or decoupled during reductive phase. Its paraffin counterpart, propane, behaved as spectator molecules throughout the whole process, demonstrating consistent olefin separation through this selective capture-and-release mechanism. I will discuss how varying the composition of the MEA exposed potential mass transport limitations that play an important role in the separation efficiency and throughput. Experiments conducted under varying potentials exhibited operational robustness of the MEA in gas separations if electric potentials are carefully tuned between 1-3V in the oxidative cycle, and at approximately -2V in the reductive cycle. This proof-of-concept demonstration represents an important step towards achieving high-performing electrochemically-modulated olefin-paraffin separations that can integrate renewable electricity sources directly and help decarbonize the chemical manufacturing industry. Figure 1

Maximizing the benefits of combining fibroin and sericin: Functionalized obsoleted silk cocoon shell for purifying oily wastewater containing Pb2+

Based on the durability of fibroin and the biocompatibility of sericin, researchers are exploring ways to maximize their advantages by combining them in the biomedical field. Fortunately, silk cocoon shell (SC) offers a natural composite material of fibroin and sericin. However, the inherent hydrophobicity of SC, the random arrangement connection of fibers, and the protection provided by the outer sericin limit its application in purifying oil wastewater. In this work, a cost-effective method was developed to improve the hydrophilicity of SC and the mechanical properties of SC by utilizing obsoleted SC as a matrix as well as by dissolving portions of sericin proteins. The polydopamine particle (PDP) was utilized as the intermediate modification layer and a supramolecular gel (SMG) was introduced to the surface of SC, further improving the surface's hydrophilicity of SC. The study indicated that SC@P-SMG has excellent mechanical properties, favorable anti-fouling properties, and superior self-cleaning ability. Furthermore, when the SC@P-SMG was applied in water purification, it could achieve multifunctional applications such as purifying wastewater containing emulsified oil and Pb2+ ions, methylene blue (MB), and oil-water mixture separation. This work provided innovative ideas to maximize the benefits of combining fibroin and sericin.

Starving Free Solvents: Toward Immiscible Binary Liquid Electrolytes for Li‐Metal Full Cells

AbstractCurrent state‐of‐the‐art Li batteries use single‐phase electrolytes; however, these electrolytes often encounter difficulty in simultaneously fulfilling the nonidentical electrochemical requirements of cathodes and anodes. Here, a class of immiscible binary liquid electrolyte (BLE) is designed by starving free solvent molecules. Based on their electrochemical stability window, 1,2‐dimethoxyethane (DME) and succinonitrile (SN) are selected as model solvents for Li‐metal anodes and LiNi0.8Co0.1Mn0.1 (NCM811) cathodes, respectively. Li bis(fluorosulfonyl)imide (LiFSI), which promotes Li+ solvation (i.e., reduces free solvents), enables the phase separation of the miscible solvent mixture (SN−DME), and an increase in its concentration strengthens the coordination of Li+−FSI− in the solvation sheath, thus yielding (anion‐derived) fluorine‐rich electrode–electrolyte interphases. The resulting BLE allows 4.4 V Li‐metal full cells to exhibit a stable capacity retention under a constrained cell condition (Li (20 µm, 4.1 mAh cm−2)||NCM811 (3.8 mAh cm−2), N (negative)/P (positive) capacity ratio = 1.08), which exceed those of previously reported binary liquid electrolytes.

Chemistry Concepts in The Process of Making Coconut Oil: A Chemistry Magazine for Senior High School

This study aims to identify the chemical concepts contained in the process of making coconut oil, then the results of the identification and documentation are compiled into a chemistry magazine for senior high schools. The process of making coconut oil is done by two methods, namely heating/traditional and fermentation. The preparation of a chemical magazine is carried out using the method according to Borg & Gall which is simplified into five stages, namely preliminary studies, planning, initial product development, field implementation tests, and product finalization. There are several chemical concepts related to the process of making coconut oil, namely macromolecules, mixture separation, boiling point elevation, and colloids. Magazine feasibility testing is done by validating and analyzing student responses. The results showed that the magazine developed was very valid with an average value of V on the components of graphics, content feasibility, presentation feasibility, and magazine language respectively 0.92, 0.91, 0.96, and 0.88. The results of the student response analysis show that the developed magazine is very feasible with an average percentage of 90%.

Layer-by-layer assembly induced strong, hydrophobic and anti-bacterial TEMPO oxidized cellulose nanofibrils films for highly efficient UV-shielding and oil-water separation

Anti-ultraviolet material with cost-effectiveness, environmental friendliness, and multifunction is urgently needed to address the serious problem of ultraviolet radiation. However, traditional anti-ultraviolet products based on plastics are unsustainable and harmful to the environment. Herein, the cellulose films with a sandwich structure using a surface assembly technique were reported. Natural L-phenylalanine was grafted onto cellulose nanofibrils via amidation to enhance their UV-shielding property. To address the hydrophilic nature and limited mechanical strength of cellulose films, we employed octadecyltrichlorosilane and 4ARM-PEG-NH2 for hydrophobic coating and mechanical reinforcement, respectively. In addition to providing complete UV resistance in the wavelength range of 200–320 nm, sample OPT5 exhibited significantly improved tensile stress, Young's modulus, and toughness, measuring 174.09 MPa, 71.11 MPa, and 295.33 MJ/m3, respectively. Furthermore, due to the presence of antibacterial amine groups, the modified film demonstrated a satisfactory inhibitory effect on the growth of Escherichia coli and Bacillus subtilis. Compared to natural cellulose films, the hydrophobically modified material achieved a contact angle of up to 121.1°, which enabled efficient separation of oil-water mixtures with a maximum separation efficiency of 93.87 %. In summary, the proposed TOCNF-based UV-shielding film with multifunctionality holds great potential for replacing petrochemical-derived plastics and serving as an applicable and sustainable membrane material.

Anomalous Diffusion of Helium and Neon in Low-Density Silica Glass.

The diffusion properties of low-density non-porous silica glasses (expanded silica glasses) were researched with the aim of searching for the molecular structure of membrane materials intended for the effective separation of helium-neon gas mixtures. It has been shown on a large number (84) of computer models of such glasses that there are molecular structures of silica in which various helium and neon diffusion mechanisms are simultaneously implemented: superdiffusion for helium and subdiffusion for neon. This makes it possible to significantly (by 3-5 orders of magnitude) increase the helium permeability of such glasses at room temperature and maintain a high selectivity for the separation of helium and neon (at the level of 104-105) at the same time.

A monolithic stationary phase with dendritic nanostructures for the separation of PEGylated proteins.

Separation of PEGylated protein mixtures into individual species is a challenging procedure, and many efforts have been focused on creating novel chromatographic supports for this purpose. In this study, a new monolithic stationary phase with hyperbranched nanostructures was chemically synthesized. For this, monoliths with a support matrix of poly (glycidyl methacrylate-co-ethylene dimethacrylate) and ethylenediamine chemistry were modified with third-generation dendrons with butyl-end groups. The new monolith was analyzed by infrared spectroscopy, confirming the dendron with butyl ligands and exhibited low mass transfer resistance as observed by breakthrough frontal analysis. This support was able to separate mono-PEG ribonuclease A from the PEGylation mixture, indicated by a single band (∼30kDa) in the electrophoretic analysis. Moreover, the separation of mono-PEGylated positional isomers was probably observed, as the protein with ∼30kDa was found in two separate peaks. Interestingly, the dendronized monolith allowed the separation of the reaction mixture into individual PEGylated species when using high ammonium sulfate concentrations (2M). A correlation between the PEGylation degree and the strength of the hydrophobic interactions on the monolith was observed. This chromatographic approach combines the natural branched architecture of dendrons and the higher capabilities of the monoliths enhancing the hydrophobic surface area, and therefore the interaction between the PEGylated proteins and ligands. Thus, the novel support represents a novel platform for the purification of PEGylated from non-PEGylated proteins with biotechnological applications.

A magnetic field augmented ultra-thin layer chromatography coupled surface enhanced Raman spectroscopy separation of hemozoin from bacterial mixture

Malaria is considered as one the most widespread disease with highest possibility of co-infection at all levels of the disease prognosis. Rapid detection and discrimination of malaria from other co-infections remains a challenge. Hemozoin is a metabolic biproduct of malaraia possessing paramagnetic property due to presence of iron at its centre. Here, we report a label free, rapid and highly sensitive magnetic field based ultra-thin layer chromatography (UTLC) coupled with surface enhanced Raman spectroscopy (SERS) technique for detection and separation of hemozoin from a bacterial mixture. Highly optimized silver nanorods chip fabricated using glancing angle deposition (GLAD) is explored for the UTLC-SERS separation. These chips possessing channel like characteristic and high surface to the volume ratio serve as excellent UTLC plates. The magnetic nature of hemozoin has been exploited for its separation from the mixture of P. aeruginosa (Gram-negative) and S. aureus (Gram-positive) by allocating a 0.6 T magnet over the UTLC flow setup. The solvent front migrated approximately to a distance of 13 mm from the sample point due to the magnetic environment. Spatially resolved SERS data was collected along the mobile phase and separation of mixture was confirmed. Further, staining of hemozoin, P. aeruginosa and S. aureus was done using methylene blue, acridine orange and rhodamine 6 G respectively. The separation was confirmed for the stained analytes. The present developed method provides plate height as low as 18 µm and hemozoin detection limit as <10 parasites/mL. Therefore, we establish a highly specific and sensitive technique capable of separating small amounts of bioanalytes, aiding in the removal of co-infections from the disease at a very early stage of infection.

Fabrication of highly selective PEBA mixed matrix membranes by incorporating metal-organic framework MIL-53 (Al) for the pervaporation separation of pyridine-water mixture

Pyridine is generally found in the effluents from the synthesis of paints, rubber chemicals, vitamins, and pesticides. This study focused on improving the pervaporation (PV) performance of polyether block-amide (PEBA-2533) membranes cast on polyvinylidene fluoride (PVDF) substrate, by incorporating the MIL-53 (Al) particles to prepare mixed matrix membranes (MMMs) for pyridine separation from the aqueous solution. MIL-53 (Al) has a larger aperture size (8.5 Å) than the molecular size of the pyridine (6.0 Å), which could allow pyridine molecules to efficiently pass through its channels. The coadjacent MIL-53 particles created relatively continuous permeation pathways for the penetrants in the MMMs, which substantially enhanced the separation performance. Impressively, the resultant MMMs displayed superior pyridine separation performance at complex conditions. At 65 °C and 0.5 wt% pyridine aqueous solution, the separation factor and pyridine flux of PEBA/PVDF membrane were 17.3 and 143.5 g m−2 h−1, which were improved using MIL-53@PEBA/PVDF MMMs to 48.1 and 226.9 g m−2 h−1, respectively. Owing to the enhanced pyridine affinity, hydrophobic property, and thermal robustness, the resultant MMMs overcame the inherent trade-off between selectivity and permeability, and also displayed the promising long-term stability. These findings may provide valuable insights for developing novel MMMs with superior separation performance.

C2-Hydrocarbon Mixture Separation on Polyethylene Membranes with Grafted Sulfonated Polystyrene in H+, Li+ and Na+ Forms

The olefin separation from their mixture with paraffins by facilitated transport membranes is a very important process for the further macromolecular compounds production. Membranes loaded with silver ions, which are responsible for the facilitated olefin transport, are instable with time due to their reduction, while those containing protons catalyze the polymerization of olefins. In this work, membranes based on polyethylene with grafted sulfonated polystyrene in various ionic forms (H+, Li+, Na+) were used for the first time for the separation of the ethylene/ethane mixture. The influence of sulfonation time, relative humidity, and various ionic forms on ethylene separation was studied. The SEM study shows a non-uniform sulfur distribution over the membrane thickness for membranes sulfonated for different reaction times. With increasing sulfonation time and relative humidity the ethylene permeability and the factor of its separation with ethane increase. Separation factors for membranes in the Li+-form are shown to be as high as for membranes in the H+-form. A possible mechanism for the facilitated ethylene transport is discussed.

Data-driven predictions of complex organic mixture permeation in polymer membranes

Membrane-based organic solvent separations are rapidly emerging as a promising class of technologies for enhancing the energy efficiency of existing separation and purification systems. Polymeric membranes have shown promise in the fractionation or splitting of complex mixtures of organic molecules such as crude oil. Determining the separation performance of a polymer membrane when challenged with a complex mixture has thus far occurred in an ad hoc manner, and methods to predict the performance based on mixture composition and polymer chemistry are unavailable. Here, we combine physics-informed machine learning algorithms (ML) and mass transport simulations to create an integrated predictive model for the separation of complex mixtures containing up to 400 components via any arbitrary linear polymer membrane. We experimentally demonstrate the effectiveness of the model by predicting the separation of two crude oils within 6-7% of the measurements. Integration of ML predictors of diffusion and sorption properties of molecules with transport simulators enables for the rapid screening of polymer membranes prior to physical experimentation for the separation of complex liquid mixtures.

Separation of near-boiling mixtures (acetic acid and water) enhanced by ionic liquid

Acetic acid aqueous solution is a common and typical near-boiling mixture in the petroleum, chemical, polymer, pharmaceutical and food industries. Because of the large number of ideal plates for separating acetic acid and water by ordinary distillation, the energy consumption and production cost are high. Designable ionic liquids (ILs) and deep eutectic solvents (DESs) are environmentally-friendly entrainers for extractive distillation. Many azeotropic systems enhanced by adding ILs or DESs have been studied, but the near-boiling water/acetic acid system is rarely discussed.In this study, an IL 1,2,3-trimethylimidazolium dimethylphosphate ([TMIM]+[Me2PO4]−) with easy synthesis, low production cost and good thermal stability was employed as the rectification entrainer for water/acetic acid system, while the DESs were easy to react in acetic acid aqueous solution and was abandoned. First, the relative volatility of water (1) and acetic acid (2) at the more difficult separation point (x1′ = 0.9) was measured using a modified Othmer still at 101.32 kPa. When the mole fraction of entrainers was 0.071, these relative volatilities were 2.80 (n,n-dimethylformamide), 2.88 (1-methyl-2-pyrrolidinone), 4.82 ([TMIM]+[Me2PO4]−) respectively. The separation performance of [TMIM]+[Me2PO4]− was 67% higher than that of 1-methyl-2-pyrrolidinone. Then, the effect of [TMIM]+[Me2PO4]− concentration on the relative volatility was investigated. The relative volatility was dramatically increased from 1.60 to 6.85 with 0–0.103 mol fraction of [TMIM]+[Me2PO4]− and was 4.28 times that in an IL-free system. After that, isobaric vapor–liquid equilibrium (VLE) data of water + acetic acid, water + [TMIM]+[Me2PO4]− and water + acetic acid + [TMIM]+[Me2PO4]− ([TMIM]+[Me2PO4]− at ∼ 5, 15, and 25 mass%) systems were determined at 101.32 kPa. Also, Based on the chemical theory and Hayden–O’Connell method, the binary energy parameters of the NRTL (Non-Random-Two-Liquid) model for these systems were regressed and the predicted values were found to fit the experimental VLE data quite well..For the first time, we have found that [TMIM]+[Me2PO4]− as an entrainer is superior to conventional volatile solvents for water/acetic acid distillation in terms of performance, which provides more choices and imagination for industry. At the same time, it promotes understanding of the influence of IL structure on water/acetic acid separation performance, and is also an important inspiration for the distillation of other near-boiling systems.

Synthesis of the Hypoxia-Inducible Factor-2α (HIF-2α) Inhibitor, 3-[(1S,2S,3R)-2,3-Difluoro-1-hydroxy-7-methylsulfonylindan-4-yl]oxy-5-fluorobenzonitrile (PT2977, Belzutifan); Efficient Replication of Established Approaches

A concise linear synthesis of hypoxia inducible factor-2α (HIF-2α) inhibitor, belzutifan was achieved by reproducing key components of previous synthetic approaches to this molecule as described in several publications and patents. Belzutifan is an orally bioavailable small-molecule (HIF-2α) inhibitor for the treatment of von Hippel-Lindau (VHL) disease-associated renal cell carcinoma (RCC) that received FDA approval in 2021. Herein, we report a 13-step synthesis of PT2977 that proceeded in good overall yield with high diastereoselectivity. Separation of diastereomeric mixtures at two different stages of the synthesis proved advantageous in ease of separation. The X-ray structure of belzutifan was determined.

Green chemistry-based fabrication of hollow fiber and flat sheet polyimide membranes for CO2/CH4 separation

In this work, the successful fabrication of polymeric hollow fiber (HF) and flat sheet (FS) membranes was examined by employing γ-butyrolactone (GBL)-a green and environmentally friendly solvent- for the polymer's dissolution following the principles of green chemistry and sustainability regarding the membrane preparation. In addition, the ternary phase diagram of the P84/GBL/water was constructed and the viscosity of dope solution was measured for different concentrations and temperatures. Their morphological characteristics of the prepared polyimide membranes were investigated through SEM analysis. CO2/CH4 separation measurements under continuous flow were performed to evaluate the efficiency of the membranes for a binary 10/90 vol.% CO2/CH4 gas mixture. The developed green HF and FS membranes exhibited comparable, and in some cases even superior, performance compared to membranes prepared using the conventional and highly toxic NMP solvent, making them highly promising candidates for CO2/CH4 separation, with a real mixture separation factor of ∼58.

Reconstruction of mixed matrix membranes by in situ vapor aminolysis for CO2/N2 and CH4/N2 separations

Membrane technology has great potential for gas separation. Incorporation of nanoporous fillers in polymers is attractive for constructing high-performance mixed matrix membranes (MMMs). However, for some mixtures, especially those molecules with similar properties, efficient membrane separation remains extremely challenging. In this study, we report post-synthetic reconstruction of MMMs by in situ aminolysis via chemical vapor deposition for enhancing gas separation performance. By utilization of amine substitution to functional groups of polymers of intrinsic microporosity and chelation to metal centers of metal-organic frameworks (MOFs), the MMMs are modified under mild conditions. Since aminolysis promotes amino grafting, boosts preferential sorption, regulates pathway, and enhances filler-polymer adhesion, the MMMs have substantially improved antiaging property and CO2/N2 separation performance, with permeability of 6986 Barrer and selectivity of 30.7. Importantly, for CH4/N2 mixture separation, that is critical for natural gas purification but difficult to separate, the MMMs also exhibit competitive selectivity and permeability of 5.0 and 897 Barrer, respectively. The performances for CO2/N2 and CH4/N2 separations can be close to and surpass the least trade-off upper bounds, respectively. Moreover, in situ aminolysis by vapor deposition has universal applicability for reconstructing various MMMs. This strategy is an alternative route to fabricate membranes for efficient separations.

Preparation and characterization of electrospun PVDF/PVP/SiO2 nanofiber membrane for oil-water separation

For oily wastewater purification, polyvinylidene fluoride (PVDF) nanofiber membranes have been widely noticed for their excellent mechanical strength and corrosion resistance. However, it is prone to serious oil fouling problems during use, resulting in reduced flux and inability to be used repeatedly. It has become a hot research topic to develop simple methods to realize its hydrophilic modification for oily wastewater treatment to address this problem. Herein, a novel separation membrane was prepared by doping polyvinylpyrrolidone (PVP) and hydrophilic silica nanoparticles (SiO2 NPs) into PVDF using a facile one-step electrospinning method. The modified membrane shows hydrophilicity, water contact angle (WCA) is 0°, oleophobicity in water, and oil contact angle (OCA) is more than 145° and has good separation efficiency and flux for both oil-water mixtures and emulsions. After 30 times of mixture and emulsion separation tests, the separation efficiency is above 99.5 % and 97 %, respectively, showing good separation and reusability. Besides, compared with hydrophilic modification methods such as surface coating and grafting, the proposed modification method is simpler and has great potential in treating oily wastewater.

An MINLP formulation to identify thermodynamically-efficient distillation configurations

Designing configurations for separation of multicomponent mixtures by distillation is challenging because of (i) combinatorial explosion of the choice set, and (ii) nonconvex nature of the governing equations. This work proposes a novel Mixed Integer Nonlinear Program (MINLP) that is formulated to identify configurations that minimize the total exergy loss/maximize thermodynamic efficiency of the separation process. The formulation in its default form has several nonlinear nonconvex equations. We propose a model reformulation via a simple variable elimination technique to reduce the system of nonlinear equations to a single equation, which we refer to as the exergy constraint. We describe the properties of exergy constraints and exploit them in deriving additional valid cuts for the problem. Finally, we use the model for a case study concerning the recovery of Natural Gas Liquids (NGLs) from shale gas.

Simple lattice model explains equilibrium separation phenomena in glassy polymers.

The Robeson bound is a theoretical limit that applies to kinetics-driven membrane separations of gas mixtures. However, this bound does not apply to sorption-driven membrane processes such as CO2/N2 separation, which lacks a theoretical explanation. As a result, we are uncertain about the factors that control the limiting behavior of sorption-driven separations. To address this issue, we employed a simple lattice model and dynamic mean field theory to examine the transport properties of disordered model structures, isolating sorption effects from purely kinetic effects. Our findings indicate that transport effects play a crucial role in sorption-driven processes, and perm-selectivity is consistently lower than sorption selectivity, which is an unattainable limit. We used basic geometric fragments of the structure to explain how transport effects emerge and manifest themselves in sorption-driven processes.