Adsorption Separation Research Articles

Skeleton design engineering of covalent organic frameworks to enable in situ incorporation of coordination sites for improved extraction of uranyl ions

The development of advanced porous materials for effectively separating uranium from nuclear wastewater or seawater is a highly coveted yet formidable task. However, the importance of the covalent organic frameworks (COFs) skeletons and the specific arrangement of adjacent atoms is often disregarded when configuring coordination settings for chelating molecules. In this study, a novel material for oxygen-enriched COFs was developed. The optimized oxygen-rich COFs showed aligned neighboring bonds and triazine groups along the skeletons, resulting in an increase in uranyl binding sites and a threefold rise in the total number of binding sites. The synergistic interaction of ether bonds and triazine groups in the π-conjugated skeletons significantly reduced the energy band gap, leading to improved uranium affinity and recovery. The adsorption capacity reached an impressive 660 mg/g, surpassing that of most COF-based adsorbents using a chemical coordination mechanism in uranium-containing aqueous solutions. This study provides valuable insights into designing novel adsorbents for uranium separation.

Uranium removal from contaminated groundwater using goethite-loaded composite microporous membrane

In this study, we have coupled adsorption and membrane separation for the removal of uranium from contaminated groundwater in environmentally relevant conditions at low energy requirements. This study mainly focuses on elucidating uranium, U(VI), adsorption mechanisms using surface complexation modeling approach in a novel goethite-loaded composite microfiltration membrane (GLM). This experiment involved immobilizing goethite nanorods in a microporous (0.22 μm pore size) poly (vinylidene fluoride) (PVDF) membrane. The effect of varying goethite loading and hydraulic residence time on U(VI) removal was investigated at field-relevant pH (i.e. pH 8.5). U(VI) adsorption (i.e. 4.95 μg·mg−1) was optimum at a goethite loading 1.20 mg·cm−2. The effect of varying hydraulic residence time had no impact on U(VI) removal which was also confirmed via performing batch adsorption kinetic experiments. GLM membrane loaded at 1.2 mg·cm−2 could treat 275 L of U(VI) contaminated water having 200 μg of U L−1 below WHO drinking water limit (i.e. 30 μg of U L−1) with 1 m2 of membrane surface area with a adsorption capacity of 6.12 μg·mg−1. Varying the pH of aqueous solution, containing U(VI) from pH 4.0 to pH 10.0, showed a significant impact on uranium uptake ranging from 0.7 μg·mg−1 to 2.63 μg·mg−1 by the composite membrane. The adsorption mechanism of uranium onto goethite was explained via the formation of bidentate surface complexes using the Surface Complexation Model (SCM). The results of batch pH edge experiments and SCM have been compared with pH experiments performed using GLM. The results of SCM predicted the batch pH edge experiment within a RMSE of 0.055. The trend of U(VI) removal in membrane experiments was observed to be similar to that of batch pH edge experiments and was well predicted SCM model. Our results showed that the novel goethite-loaded membrane has the potential for the effective removal of uranium with a lower specific energy consumption.

The Impact of Adsorption Property Modification by Crosslinkers on Graphene Oxide Membrane Separation Performance

The health risks associated with the presence of heavy metals in drinking water can be severe. To address this issue, membrane separation technology is one of the consolidated alternatives. Inorganic, porous membranes were found in applications where low energy consumption is highly desirable. The selectivity of these membranes is attained by functionalisation. Graphene oxide functionalised membrane technology is promising for removing heavy metal ions. This work summarises, discusses and presents the relationship between adsorption and overall membrane separation process performance for heavy metal ions removal from wastewater when a graphene oxide-functionalised membrane is used. The separation performance depends on the hydrophobic interactions of the membrane and the solute. The electrostatic interaction between the negatively charged membrane surface and positively charged metal ions facilitates the adsorption, leading to the rejection of these metal ions. The influences of the chemical nature of the modifiers of graphene oxide layers are highlighted.

Energy-Efficient Separation of Xylene Isomers through Stacked 1-Aminopyrene Polymer Composite.

Developing high-performance adsorbents for energy-efficient separation of xylene isomers has important research and application value. Identification and separation of xylene isomers (PX, MX, and OX) at room temperature based on the different relative positions of two methyl groups on the benzene ring is an unprecedented attempt. Herein, 1-aminopyrene polymer (PAP) is designed and electro-synthesized composited with a supporting electrolyte as an adsorbent for the separation of xylene isomers using a multi-stage dispersed liquid-solid adsorption process at room temperature. Each -NH-pyrene-NH- unit can form a force field to identify and discriminate xylene isomer through π-π interaction combined with -CH3···-NH- interactions of different strength, thereby achieving separation of PX, MX, and OX isomers by amplifying the slight differences in the adsorption capacity and diffusion rates. The density functional theory (DFT) simulations provide a more quantitative analysis of the adsorbate-adsorbent interactions to illustrate PX > MX > OX order of adsorption selectivity. This study may offer an alternative strategy for the precise designing of energy-efficient and adsorption-based separation materials.

Separation of molybdenum and tungsten using selective adsorption with zirconium based metal organic framework

BackgroundThe separation of tungsten and molybdenum has always been a significant challenge. Metal organic frameworks (MOFs) has potential to solve the problem. In this study, the adsorption and separation performance of UiO-66 for tungsten and molybdenum and adsorption mechanism were investigated. MethodsUiO-66 was synthesized by solvothermal method. The physical and chemical properties of UiO-66 and adsorption mechanism were characterized and analyzed by XRD, SEM-EDS, FT-IR, Zeta-potential, XPS and thermodynamic analysis, the adsorption and separation performance of Mo/W using UiO-66 were evaluated by ICP-OES. Significant findingsUiO-66 with uniform pore size could be obtained under the conditions of crystallization for 24 h at 180 °C. This study revealed superior Mo/W separation performance under acidic conditions, where the adsorption capacity for Mo (QMo) of UiO-66 was 219.4 mg⋅g−1 and the highest separation factor (βMo/W) was 52.3. It was found that the mechanism involved the effect of pore size, electrostatic attraction and the metal point Zr had stronger affinity for Mo. This material was expected to serve as an eco-friendly and reusable adsorbent for separation of tungsten and molybdenum in resource recovery, aiming for high-quality regeneration of both metals.

Microbial fuel cells: A potent and sustainable solution for heavy metal removal

The global water pollution problem is becoming increasingly crucial. One of the major contributors to water pollution is the presence of heavy metals. Heavy metals pose significant threat to both humans and all ecosystems. Various factors influence the removal of heavy metals from wastewater, including pH, temperature, natural organic matter (NOM), and ionic strength, which vary based on the chemical properties of the pollutants. More effective and modern approaches receive attention and extensively researched to substitute traditional methods such as adsorption, membrane filtration, and chemical-based separation. Among these methods, Microbial fuel cells (MFCs) are particularly intriguing. This review article focuses on MFCs and their potential applications in various fields, including clean water production. MFCs represent an innovative technology that not only generates electricity, but also demonstrates significant potential for heavy metal removal from wastewater. Cathodic chamber of MFCs effectively reduces heavy metals, while organic substrates act as carbon and electron donors in the anodic chamber. Through various mechanisms, including direct and indirect metal reduction, biofilm formation (metal sequestering), electron shuttling, and synergistic interactions among microbial communities, microorganisms exhibit remarkable efficiency in removing metals. Studies showed that dual- and single-chamber MFCs could efficiently remove a range of heavy metals, including chromium, cobalt, copper, vanadium, mercury, gold, selenium, lead, magnesium, manganese, zinc, and sodium, while simultaneously generating electricity, achieving high removal efficiencies ranging from 25% to 99.95%. This range of efficiency varies depending on the specific contaminant being targeted, the concentration of the contaminant, as well as the operating conditions such as pH and temperature. Moreover, MFCs demonstrated a wide range of power outputs, typically ranging from 0.15 W/m² to 6.58 W/m², depending on the specific configuration and conditions. These findings underscore the potential of MFCs as a sustainable and efficient approach for both wastewater treatment and energy generation.

The adsorption and separation of tungsten and molybdenum by chitosan and chitosan-D301: Experiments and DFT theoretical calculation

The adsorption and separation of tungsten and molybdenum are important for efficient recycling of W-Mo resources, which requires green and efficient adsorbents. In this paper, Chitosan (CS)-D301 material was obtained by impregnation method and was applied to adsorb and separate W and Mo in solutions. The adsorption optimization results indicated that W was adsorbed by CS-D301, the separation factor of W/Mo increased to 26.45 compared with that of CS 21.34. The desorption efficiency was still above 94 % after five adsorption–desorption cycles. FT-IR, XPS and DFT theoretical calculations indicated that the surface group N+-R of CS-D301 showed more affinity for W, making it easier to selectively adsorb W over Mo than CS only. N was the surface-active adsorption site, and the adsorption process belonged to chemical adsorption with an adsorption energy of Eads = −957.64 kcal/mol. CS-D301 was expected to become green adsorbent for efficient separation of W and Mo to support resource recovery, protection and sustainable development.

Engineering Trifluoromethyl Groups in Porous Coordination Polymers to Enhance Stability and Regulate Pore Window for Hexane Isomers Separation.

Effective separation of hexane (C6) isomers is critical for a variety of industrial applications but conventional distillation methods are energy-intensive. Adsorptive separations based on porous coordination polymers (PCPs) offer a promising alternative due to their exceptional porosity and tunable properties. However, there is still an urgent need to develop PCPs with high stability and separation performance. This study investigates how substituting a methyl (-CH3) group with a trifluoromethyl (-CF3) group can regulate pores and hydrophobicity in PCPs. This precise adjustment aims to enhance stability and improve the kinetic separation performance of hydrophobic C6 isomers by considering the size and hydrophobicity of the trifluoromethyl group. Two isostructural PCPs with pcu topology, PCP-CH3 and PCP-CF3, were synthesized to vary pore diameters and hydrophobicity based on the presence of -CH3 or -CF3 groups. PCP-CF3 showed greater stability in water compared to PCP-CH3. While PCP-CH3 had high adsorption capacities, it lacked selectivity, whereas PCP-CF3 demonstrated improved selectivity, particularly in excluding dibranched isomers. Dynamic column separation experiments revealed that PCP-CF3 could selectively adsorb linear and monobranched isomers over dibranched isomers at room temperature. These findings highlight the potential of fluorine-modified PCPs for efficient isomer separation and underscore the importance of stability improvement strategies.

Polysulfone (Psf) Mixed Matrix Membrane incorporating Titanium Dioxide (TiO2)/Polyethylene Glycol (PEG) for the removal of copper

The global increasing contamination of water resources with toxic metals such as copper (Cu), poses severe threats to human health and aqueous ecosystems. Therefore, the ultrafiltration mixed matrix membranes (UF MMMs) possess an applicable approach for the removal of copper ions. This novel fabricated technology can be applied in various wastewater treatment systems for the removal of heavy metals, especially copper. MMMs were fabricated by blending polysulfone (Psf) with additives into the dope solution via the phase inversion method by incorporating titanium dioxide (TiO2) and polyethylene glycol (PEG) in Psf MMMs. Seven Psf MMMs samples labelled M0 to M6, each with its own formulation, were prepared and tested for density, porosity, and degree of Cu retention. MMMs were further characterized via Fourier transform infrared spectroscopy (FTIR), which revealed the range of the IR spectrum of Psf polymer membrane from 1319 cm-1 to 1600 cm-1, 1650 cm-1 to 3400 cm-1 for PEG, and 800 cm-1 to 3600 cm-1 for TiO2 NPs. As for the scanning electron microscopy (SEM), M6 (Psf/TiO2/PEG 6000) was found to be the most dense and highest porous morphology asymmetric Psf MMM. The retained percentage of Cu and flux for M6 attained the highest value of 80.3% and 136.99 L/m2 .h respectively, whereas for the neat Psf membrane, M0 exhibited the lowest retained percentage of Cu and flux, about 25.8% and 61.64 L/m2.h. The inclusion of pore former and additives has shown an improvement of 54.5% in the copper rejection. Moreover, M6 displayed the highest antifouling properties compared to other Psf MMMSs. This study proves that PEG and TiO2 additives have significant potential to improve membrane performance due to the highest percentage of Cu retained on the surface of the membrane as adsorptive separation on Psf MMMs.

Adsorptive separation of anthracene and carbazole by carboxyl-functionalized carbon material derived from MAF-6

Anthracene and carbazole are high-value heavy carbon resources mainly found in the anthracene oil fraction of high-temperature coal tar. Because of their similar structures, traditional solvent crystallization methods are not capable of achieving the separation of high-purity anthracene and carbazole. In this study, MAF-6, a material that can be synthesized in large quantities at room temperature, was used as a sacrificial precursor, carbonized (MC-1000), and subsequently oxidized to form carboxyl-functionalized carbon material (CMC-1000). The presence of carboxyl groups, along with lactones, hydroxyl groups, and carbonyl groups in MC-1000 and CMC-1000, was confirmed through XPS spectra and Boehm titration. CMC-1000 showed an increase of 5.7 mmol/g in oxygen-containing functional groups. The adsorption and separation capacities of MAF-6, MC-1000, and CMC-1000 for anthracene and carbazole in model oil were investigated. FT-IR analysis and DFT calculations demonstrated that the major interaction between CMC-1000 and carbazole involved hydrogen bonding (N–H···O and N–H···N). The results show that CMC-1000 has a high separation selectivity for carbazole over anthracene, with a selectivity of up to 44.4. The formation of hydrogen bonds between the N–H group of carbazole and the oxygen-containing groups on CMC-1000 plays an essential role in achieving high adsorption capacity and selectivity. In addition, CMC-1000 showed strong regenerative capacity, maintaining a selectivity above 29.7 over five cycles.

Comparative evaluation of adsorptive and repulsive separation using cellulose nanofiber/calcium alginate composite hydrogel filtration membranes with improved degradability

Among several approaches to address hard-to-manage dye wastewater, adsorption is one of the widely used methods, but the usage of these adsorbents can be constrained by their high material and process costs depending on the adsorbent materials as well as handling a large amount of adsorbents in a bulk solution. To overcome the problems, hydrogel membranes have recently attracted much attention because they can provide several strengths such as adsorption removal, confined adsorption sites, and filtration separation. However, to the best of our knowledge, it is still quite rare to find an in-depth comparative evaluation of adsorptive removal and repulsive separation in hydrogel membrane filtration. Herein, this study aims to bridge the gap between existing knowledge and undisclosed phenomena. Through a thorough comparative evaluation of adsorptive removal and repulsive separation in hydrogel membrane filtration, we found that repulsive separation was more suitable and sustainable than adsorptive removal because it was free from internal membrane fouling, adsorption sites’ saturation, and the cake layer formation on the surface. As a result, the hydrogel membranes could maintain excellent real-time separation performance while mitigating severe flux and rejection decline. Furthermore, we significantly improved the degradability of the spent hydrogel membrane under high saline conditions by 6.3 times compared to the control membrane by fine-tuning the structural properties via dual crosslinking, while maintaining the mechanical properties during filtration. It was possible due to the extended distance between polymer chains by dual crosslinking, reducing the burden imposed by plastic waste generated from the spent membrane.

High-performance metal-organic frameworks for efficient adsorption, controlled release, and membrane separation of organophosphate pesticides

Metal-organic frameworks (MOFs) are considered good choices for the absorption, separation, and release of various substances. The rapid increase in the number of MOFs being produced makes it impractical to conduct experimental research to identify the most promising candidates in these areas. Therefore, computational screening has emerged as a robust approach. We employed this approach to identify the most efficient MOFs for the removal, separation, and controlled release of organophosphorus pesticides, including diazinon, chlorpyrifos, and chlorpyrifos-methyl. From a database of approximately 14,000 MOFs, 584 MOFs with the largest cavity diameters were used in the screening process to evaluate promising candidates for each pesticide. Monte Carlo simulations were used to estimate the pesticide uptake capacities and isosteric heats of the selected MOFs. The structural properties of MOFs were correlated with their adsorption capacities and isosteric heats. Computational screening identified 325, 330, and 450 MOFs as potential absorbents and carriers for diazinon, chlorpyrifos-methyl, and chlorpyrifos, respectively. Additionally, it proposed 235, 254, and 135 MOFs as membranes for the effective separation of these organophosphorus pesticides. The reactivity of the pesticides was explored using quantum mechanics calculations. Molecular dynamics simulations of the top three MOFs with high uptake capacities for each pesticide were performed and analyzed to understand the interactions between the MOF, pesticide, and water molecules. The solvation-free energies of the pesticides were calculated for various solvents to identify the most effective solvent for desorbing pesticides from the MOFs, thereby enabling MOF regeneration.

Oriented 1D Metal-Organic Frameworks for Selective Chemisorption by a Substitution-Insertion Mechanism.

Chemisorption on organometallic-based adsorbents is crucial for the controlled separation and purification of targeted systems. Herein, oriented 1D NH2-CuBDC·H2O metal-organic frameworks (MOFs) featuring accessible CuII sites are successfully fabricated by bottom-up interfacial polymerization. The prepared MOFs, as deliberately self-assembled secondary particles, exhibit a visually detectable coordination-responsive characteristic induced by the nucleophilic substitution and competitive coordination of guest molecules. As a versatile phase-change chemosorbent, the MOFs exhibit unprecedented NH3 capture (18.83 mmol g-1 at 298 K) and bioethanol dehydration performance (enriching ethanol from 99% to 99.99% within 10 min by direct adsorption separation of liquid mixtures of ethanol and water). Furthermore, the raw materials for preparing the 1D MOFs are inexpensive and readily available, and the facile regeneration with water washing at room temperature effectively minimizes the energy consumption and cost of recycling, enabling it to be the most valuable adsorbent for the removal and separation of target substances.

Theoretical investigations on the purification of petroleum using desulfurization process: Analysis and optimization of process

This paper introduces a comprehensive approach for predicting chemical concentrations (C) of sulfur compound in a two-dimensional space (x, y) by numerical solution of mass transfer equation and integration of machine learning. Data of training/validation are obtained from mass transfer modeling on adsorption separation utilizing porous adsorbent for petroleum desulfurization. Mass transfer modeling data were utilized for machine learning models which included three different regression models, namely Support Vector Machine (SVM), Decision Tree Regression (DT), and Multilayer Perceptron (MLP). The hyper-parameters of these base models were optimized using the Grey Wolf Optimization (GWO) algorithm. The ensemble models, denoted as ADA-DT, ADA-MLP, and ADA-SVM were assessed based on key performance metrics, including R2, MAE, RMSE, and MAPE. Results demonstrated the efficacy of the ensemble models in capturing complex relationships within the dataset. ADA-DT obtained an exceptional R2 score of 0.99031, highlighting its outstanding predictive accuracy. Similarly, ADA-MLP and ADA-SVM showed great accuracy, achieving R2 of 0.88272 and 0.96842, respectively. In this study, we uncover valuable insights into the application of ensemble methods and hybridized optimization methods for accurate and robust regression modeling in chemical concentration prediction scenarios applicable for petroleum engineering.

Positively Photo-Responsive Adsorption Over Binary Copper Porphyrin Framework and Graphene Film Sorbents.

Photo-responsive adsorption has emerged as a vibrant area because it provides a promising route to reduce the energy consumption of the traditional adsorption separation. However, the current methodology to fabricate photo-responsive sorbents is still subject to the photo-deforming molecular units. In this study, a new initiative of photo-dissociated electron-hole pairs is proposed to generate amazing adsorption activity, and prove its feasibility. Employing CuPP [PP = 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin] framework nanosheets compounded with graphene, binary film (BF) sorbents are successfully fabricated. The paradigmatic BF nanostructure brings about efficiently photo-excited electron-hole pairs with durable enough lifetime to meet the needs of microscopic adsorption equilibrium, which ultimately alters the electron density distribution of adsorption surface, and thus markedly modulates the adsorption activity. Therefore, an amazing photo-enhanced adsorption capability for the index gas CO can be gotten. Once exposed to the visible-light at 420nm, the CO adsorption capacity (0°C, 1bar) is risen from 0.23mmolg-1 in the darkness to 1.66mmolg-1, changed by+622%. This is essentially different from majority of current photo-responsive sorbents based on photo-deforming molecular units, of which adsorption capability is only decreased with photo-induction, and the maximum rate of change reported is just -54%.

A MOF built on 8-connected Y3 nodes demonstrates simultaneous reverse adsorptive separation: ethane over ethylene and propane over propylene

A MOF built on 8-connected Y3 nodes demonstrates simultaneous reverse adsorptive separation: ethane over ethylene and propane over propylene

Efficient adsorption and selective separation of high value-added chemicals from simulated expired energy drinks by metal-organic frameworks

Expired energy drinks contain a certain amount of high-value chemicals, such as caffeine, that possess biological activity. The recovery and recycling of these valuable chemicals plays a crucial role in promoting the achievement of carbon emission reduction goals. In this work, 11 kinds of water-stable MOFs with different pore channel structure were synthesized and used for the first time to adsorb caffeine, nicotinic acid, or taurine from water. It has been found that the size effect of the topological structure of MOF adsorbents is the fundamental factor governing their adsorption performance. The optimized adsorbent UiO-67 exhibits excellent adsorption performance for caffeine and nicotinic acid, with respective adsorption capacities of 830 mg/g and 583 mg/g. The investigated MOF has a very low adsorption capacity for taurine (48 mg/g); therefore, selective separation of caffeine/taurine and nicotinic acid/taurine was achieved. The adsorption process can be accurately described by both the Langmuir model and pseudo-second-order model. Adsorption mechanism reveals that the main driving forces of the adsorption process are π-π interaction between UiO-67 and CN in caffeine, as well as hydrogen bonding interactions between the N atom of caffeine’s two CO groups and μ-OH of UiO-67.

Comparison of upward and downward flow in high-pressure bulk CO2 gas adsorption on NaY zeolite fixed bed

Adsorption is an appealing technology for the removing of CO2 from natural gas because it can handle high CO2 concentrations at high pressures. The determination of mono-component breakthrough curves provides heat and mass transfer parameters to assess separation effectiveness that can be used for simulation of swing adsorption separation processes (PSA, TSA etc.). However, in lab-scale fixed-bed adsorption, it may be challenging to perform this assessment due to low flow conditions that are usually employed, affecting the flow regimedepending on the operation conditions. In this sense, this work aimed to evaluate the effect of flow regime configurations and difference in gases densities by means of residence time distribution (RTD) analysis in the PSA of CO2 in a NaY zeolite fixed bed , in order to to collect information that satisfy pipeline specifications in industrial applications. A high-pressure lab-scale apparatus was used with NaY particles of 0.7250 mm mean diameter, a 10.5 cm bed height , and a tubular column of 2.0 cm internal diameter. The upward and downward flows were conducted under 528.82 ± 4.59 NmL min−1 inlet mass flow rate, 51 bar, and 30 °C. The RTD analysis was performed to verify the flow regime, and mass transfer zone (MTZ) length was estimated. It was observed that downward flow conditions promoted higher concentration spread than upward flow. RTD analysis showed that downward flow is dominated by laminar convection while the upward flow is dominated by dispersion. MTZ length increased from 0.64 cm in upward flow to 5.81 cm in downward flow. Therefore, assessing CO2 flow conditions and, additionally, the difference in gases densities, are important steps that should be taken when dealing with fluid adsorption under high pressure because different densities between fluid components severely changed and affected flow regime and, consequently, separation effectiveness.

Apple Tree Root‐Derived Biochar/Iron Oxide Triphasic Nanocomposite for Wastewater Treatment and Microwave Absorption

AbstractIn this work, two major sources of pollution: (1) Water pollution due to heavy metals, and (2) Electromagnetic wave (EMW) pollution, often regarded as the fourth category of pollution (after air, water, and soil pollution) are addressed. A unique bio‐based triphasic nanocomposite (Fe3O4/α‐Fe2O3/carbon) is synthesized and its superior properties are demonstrated to address both types of environmental pollution. The nanocomposite, derived from lightweight apple tree roots, is used for Pb (II) ion removal from aqueous solutions via adsorption and magnetic separation. The biomass‐derived highly porous biochar decorated with iron‐oxide showed adsorption efficiency of nearly 100% and corresponding capacity of 149 mg.g−1 under optimal conditions for initial Pb (II) concentration of 50 mg.L−1. Furthermore, a remarkable adsorption capacity of 731 mg.g−1 is achieved using lower amount of the adsorbent for a slightly lower efficiency (97%). In addition, the mesoporous composite showed excellent EMW absorption efficiency with effective absorption bandwidth of 7.8 GHz and reflection loss of −61.7 dB, arising from very good impedance matching, and high dielectric and magnetic losses. This work establishes the multifunctional properties of the synthesized composite, and addresses the UN Sustainable Development Goal (SDG) 6 (Clean water and sanitation) and SDG 13 (Climate action, including pollution management).

Separation of 2,3-Butanediol from Fermentation Broth via Cyclic and Simulated Moving Bed Adsorption Over Nano-MFI Zeolites.

The biomass-based platform molecule 2,3-butanediol (2,3-BDO) has a wide range of applications in production of sustainable fuels, chemicals, synthetic rubber, and others. However, the selective separation of 2,3-BDO from multicomponent fermentation broths presents challenges due to its low concentration, high solubility in water, high boiling point, and presence of many other species. Here, we demonstrate remarkably selective enrichment and recovery of 2,3-BDO from a corn stover hydrolysate fermentation broth by a pure-silica nano-MFI-type zeolite adsorbent. By means of cyclic and simulated moving bed adsorption processes, we obtained concentrated aqueous 2,3-BDO streams from the fermentation process stream with ∼93% purity and 3-fold enrichment, and >98% purity and 8-fold enrichment, respectively. These findings provide strong support for large-scale adsorptive separation for biobased 2,3-BDO production.