The development of efficient adsorbents for water-based adsorption thermal energy storage (ATES) is essential for the large-scale utilization of low-cost and renewable energy, as the performance of these systems highly depends on the choice of adsorbent-water working pair. While metal-organic frameworks (MOFs) have attracted significant attention for thermal energy storage applications, a systematic evaluation of their suitability as adsorbents for water-based ATES remains limited. In this study, we intend to employ high-throughput screening (HTCS) combined with advanced Monte Carlo simulations to systematically screen the experimentally synthesized MOFs included in the novel MOSAEC-DB for the application in our in-house prototype ATES tank. MOSAEC-DB is the most accurate MOFs database, comprising error-free crystal structures and density functional theory (DFT) fitted partial charges. A large number of MOFs are identified that exhibit excellent performance when benchmarked against the current state-of-the-art zeolite materials in a specific application. Based on the performance assessment metrics, including the energy density (hTES), working capacity (Δn), and regenerability (R%), six top performers are selected for their extraordinary adsorbent-water working-pair performance. These top-listed candidates exhibit outstanding thermal stability above 523.15 K (250 °C), as reported in the corresponding literature. The obtained hTES of the best-performing candidates is over 450 kWh/m3, while commonly used Zeolites (13X and 4A) exhibit between 200 and 400 kWh/m3, depending on operating conditions. This systematic analysis provides a clear recommendation for the bulk synthesis of these MOFs and their subsequent evaluation in practical, real-world ATES experiments.

Vacuum membrane distillation is foreseen as a membrane unit operation capable of providing access to drinking water in the future, through the saline water desalination. To increase the permeation of standard hydrophobic membranes, such as PVDF, mixed matrix membranes are defined as the next generation of membranes and prepared by adding a filler into the polymer phase. Therefore, the aim of this work was to evaluate the effect of a chabazite zeolite filler (from 0.5 to 4 wt%) into PVDF membranes, which were prepared by a non-solvent induced phase separation, and later tested, for the first time, for water desalination application at different operating temperatures. Chabazite was selected due to its high-water affinity (comparable to zeolite 4A or 13X) and exceptional hydrothermal stability. To explain the impact of the chabazite, resulting membranes were thoroughly characterized with different analytical techniques, such as scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), nitrogen sorption, gas liquid porometry, water contact angle, and mechanical testing. As part of the outcomes, significant enhancement of the desalination performance was observed upon the addition of the chabazite; with the 4 wt% formulation being the best-performing. The permeate flux at 40°C increased 2.7 times compared to the pristine PVDF membrane, e.g., 6.133 ± 0.540 and 2.256 ± 0.203kg m- 2 h- 1, respectively. Despite different nature of the chabazite (hydrophilic) and PVDF (hydrophobic), the compatibility was sufficient to avoid formation of non-selective gaps and completely reject salt (99.99%). The membrane performed stable, with high salt rejection, for over 16h before pore wetting was observed. Although, some issues with chabazite aggregation and pore wetting were observed, the chabazite demonstrated promising potential as a filler that enhances water transport.

Sorption thermal energy storage is pivotal for enhancing renewable energy utilization and supporting the transition to carbon neutrality. Its performance hinges on the formation and dynamic evolution of the reaction zone. However, the lack of in situ, spatially resolved measurement tools has hampered a mechanistic understanding and rational design. To address this, this study presents a method for characterizing the reaction zone dynamics through high-resolution intra-reactor temperature profiling. Applying this method to a zeolite 13X packed-bed reactor, we establish, for the first time, quantitative empirical correlations between operating parameters and these intrinsic reaction zone properties. A key finding is that the stable duration and output temperature are governed by the length, propagation velocity, and exothermic area of the reaction zone, coupled with the total sorption heat. Furthermore, the effects of the four critical operational parameters, including inlet air temperature, relative humidity, airflow rate, and packing thickness, on both the reaction zone characteristics and thermal output performances were systematically investigated. By integrating these mechanistic insights, we propose a hierarchical control strategy and actionable application guidelines to tailor the thermal output on demand.

This work investigates commercial activated carbon felt (ACF) as a selective adsorbent for CO2 separation from methane in pressurized fixed-bed columns, for potential use in off-shore natural gas purification. Pristine ACF was chemically modified, aiming to improve its adsorption capacity, followed by comprehensive characterization using TGA, XRD, FT-IR, N2 physisorption, SEM, and XPS to evaluate the textural properties and surface chemistry of the material. Breakthrough curves for CO2 uptake were obtained at 35 °C, up to 10 bar, for both the individual gases and binary CO2 and CH4 mixtures. The pristine ACF presented a high specific surface area (1946 m2 g-1), a microporous structure, and limited surface oxygen groups, resulting in an exceptional experimental CO2 adsorption capacity of 12.2 mmol g-1 at 10 bar and a CO2/CH4 selectivity ratio of 6.7, comparable to that of commercial zeolite 13X. Surface oxidation with nitric acid increased the quantity of oxygen groups, but severely degraded the textural properties, reducing adsorption performance. The results showed that the adsorption on ACF was primarily governed by the textural properties, with the pristine ACF outperforming several benchmark materials, including amino-MOFs and functionalized carbons. The findings highlighted commercial ACF as a promising low-cost and scalable adsorbent for natural gas decarbonization in pressure swing adsorption (PSA) systems.

Tailoring the polarity of 13X zeolite with glycine for efficient capture of oxygenates from Fischer-Tropsch oil

ABSTRACT Catalytic CO 2 methanation offers a sustainable approach to convert waste CO 2 into high‐value methane (CH 4 ). However, designing highly efficient and stable catalysts that operate under harsh conditions remains a significant challenge. The interaction between the active metal and the support material (MSI) plays a critical role in determining the activity and stability of the catalyst. Here, we report the tailoring of MSI by regioselective anchoring of Ni and Co around the edges of hierarchical porous zeolite 13X (h13X), leveraging crystal defects modulated by amine and silanol groups. Scanning transmission electron microscopy and electron energy loss spectroscopy analysis confirmed the growth of approximately 3‐nm thick nanolayers of Ni and Co around the edges of h13X crystals. The XPS and H 2 ‐TPR analysis of the catalysts revealed shifts in binding energies and reduced H 2 consumption, corroborating stronger MSI and electronic interaction between Ni and Co. The optimized catalyst (AF‐7.5NiCo/h13X) exhibited a maximum CO 2 conversion of 74.4% with a CH 4 selectivity of 98% at 20 bar and 400°C under a GHSV of 60,000 mL g cat ⁻¹ h⁻¹ and an activation energy of 55 kJ mol⁻¹. More importantly, the catalyst demonstrated stability, with consistent CO 2 conversion performance over a month, showing no discernible decrease. The enhanced and stable performance of the catalyst is attributed to the stronger MSI and the sub‐5‐nm thin layers of Ni and Co over h13X.

Abstract Pervaporation (PV) is a promising alternative to distillation for biofuel dehydration, yet fabricating thin, defect‐free zeolite membranes remains challenging. In this work, a synergistic strategy combining nanoseeds, fluoride mineralizers, and ultradilute precursors was developed to construct high‐quality faujasite (FAU) membranes. Nanoseeds provided compact seed layers, fluoride promoted crystal intergrowth while suppressing non‐selective channels, and ultradilute precursors slowed crystallization yielding ~2.4 μm membranes with low defect density. Performance analysis confirmed that PV separation followed an adsorption‐diffusion mechanism. The optimized membrane achieved excellent fluxes of 3.70 kg/(m 2 h) with a separation factor of 1520 for a 10 wt% water/isopropanol mixture and 6.01 kg/(m 2 h) with a separation factor of 742 for a 20 wt% water/ n ‐butanol mixture. These results surpassed the results of previously reported membranes and demonstrated how this cooperative strategy provides a viable pathway for scalable fabrication of defect‐free thin zeolite membranes.

A triple-port automatic high-pressure volumetric sorptionanalyzerwas set up for sorption measurements over the temperature range of(273.15–368.15) K and pressures up to 10 MPa. The main functionof this apparatus is to rapidly screen porous materials for the separationof a specific gas mixture by measuring adsorption isotherms. Measurementswith empty sample containers were carried out to evaluate potentialsystematic errors. Validation measurements on commonly studied cases(CO2 adsorption on Zeolite 4A, ZIF-8, and Zeolite 13X)were performed, and the excellent agreement with results of literatureindicates the high reliability of the measurement system. A comprehensiveuncertainty analysis was carried out to determine the uncertaintyof measurement results and to propose future improvements of the system.Later, the measurement system was applied to screen suitable materialsfor the separation of refrigerant blends, which are composed of sixpure refrigerants (R-32, R-125, R-1234yf, R-134a, R-1234ze­(E), andR-290). The studied porous materials include six metal–organicframework samples, five zeolite samples, and one activated carbonsample. The results show that all zeolite samples investigated (Köstrolith3AK, 3ABFK, 3ABFK­(HSD), 4AK, and 4ABFK) exhibit a higher adsorptioncapacity for R-32 than for the other five refrigerants, with Köstrolith4ABFK showing the highest selectivity. This makes it possible to useany of these zeolite samples to separate R-32 from the R-410A blend(a mixture of R-32 + R-125, to be phased down in the European Union)or even separate R-32 from the mixtures composed of any of these sixrefrigerants. The other studied porous samples do not yield any promisingresults for the refrigerant blend separation.

Abstract Anthropogenic CO 2 emissions to the atmosphere are one of the most concerning climate issues in the modern era. This prompts scientists to look forward to carbon capture devices. Temperature swing adsorption (TSA), in particular, is a critical and successful technique for reducing CO 2 emissions and achieving carbon neutrality in CO 2 adsorption technology. In this work, the effectiveness of TSA for CO 2 capture on adsorbent zeolite 13X in a post-combustion setting is evaluated. The breakthrough curves from the adsorption processes were measured using a numerical model that was created. In this assessment, four common adsorbent materials like, Mg-MOF-74, zeolite 13X, activated carbon, and Zeolite-NaUSY, have been selected for comparative analysis. The developed model is verified using experimental data from the literature and is found to fit well, with a maximum probable error of ±11.24 %. Further, this numerical model has also been validated against the TSA models for signifying the accuracy of the proposed model. Analysis is done for the adsorber bed’s design and performance parameters, including CO 2 purity, CO 2 recovery, CO 2 concentration ratio and adsorption efficiency of CO 2 , across an inlet temperature range of 303–393 K, where 393 K represents an upper sensitivity limit relevant to regeneration conditions rather than optimal adsorption operation. The results demonstrate that temperature significantly influences TSA cycle behavior, capturing the transition from adsorption-dominant to desorption-dominant regimes, with a 17.37 % variation in concentration ratio across the studied temperature range. Additionally, Mg-MOF-74, activated carbon, zeolite-NaUSY, and zeolite 13X were evaluated as sorbent materials for assessing comparative adsorption performance. The proposed numerical model provides a reliable predictive tool for analyzing TSA performance under varying thermal and material conditions.

Façade-integrated solar cooling technologies enable the utilisation of façade surface potential and the provision of resilient cooling. This work compares three solar cooling scenarios, positioning a solar cooling element in the west and east façades. The 2ACE scenario is based on a compact adsorption cooling concept, while the 2PV scenario directly drives a compression chiller with photovoltaic elements, and 2PVB incorporates an additional battery. All Modelica system models are implemented in Modelon Impact and operated using dynamic optimisation for the hottest day of the year. Results indicate that the 2ACE scenario, utilising the adsorbent Silica Gel SG123, achieves near to double the self-sufficiency compared to Zeolite 13X. No clear optimal area balance between west and east elements is apparent. The 2PV scenario only surpasses the 2ACE scenario’s self-sufficiency with increased total element area, whereas 2PVB enables a drastic increase and complete self-sufficiency. This highlights the limitation of the adsorption cooling scenario due to its inability to compensate for ventilation’s electrical energy consumption. However, photovoltaic scenarios are heavily reliant on the assumed energy efficiency ratio. Additionally, slender buildings with a low AV ratio require less façade area to achieve the same self-sufficiency level as wider buildings.

This research investigates the optimization of oxygen purity in Pressure Swing Adsorption (PSA) systems using four different zeolite materials—3A, 4A, 5A, and 13X—for air separation applications. The experimental setup involved packing zeolite samples into PSA adsorption beds and systematically optimizing cycle parameters such as pressure, flow rate, and regeneration temperature. Ambient air containing 21% oxygen was used as the feed gas, and the system operated at a column pressure of 2 bars. Zeolite 13X consistently exhibited the highest oxygen purity, reaching up to 95.9% over multiple cycles, followed by 5A, 4A, and 3A. To complement the experimental work, a machine learning regression framework was applied using 10 models to predict oxygen purity based on key process variables. Linear Regression emerged as the most accurate model, achieving an R2 score of 0.9919. Feature importance analysis revealed that adsorption capacity, flow rate, and pore size were the most influential factors in determining oxygen purity. These findings highlight the critical role of material selection and data-driven modeling in enhancing PSA system performance, with direct implications for medical, industrial, and environmental applications requiring high-purity oxygen streams.

A multi-scale analysis of CO2 adsorption in zeolite 13X

Despite global efforts to reduce landfill use for municipal waste, many sites remain active, and older closed sites still require management, particularly regarding leachate. Landfill leachate contains varying levels of organic and inorganic pollutants, generated through biological and physicochemical processes following water infiltration. Its complex composition—including COD, inorganic macro-components, heavy metals, and xenobiotics—necessitates effective treatment technologies to enable safe discharge into surface waters. This study compares low-cost, eco-sustainable adsorbents for the removal of ammonium, trace elements (Cd, Be, Fe, Cu, Ni, Pb, Cr, As, Sn, Sb, Se), and color (as an indirect measure of organic compounds) from urban landfill leachate. In more detail, six biochars from different biomass feedstocks and pyro-gasification conditions as well as natural chabazite and synthetic zeolite 13X (FAU-type) were investigated. After characterization, biochars were characterized and adsorption performance was assessed. Removal performance was comparatively evaluated after 24 h batch contact under fixed experimental conditions. Results showed that gasified biochars achieved high removal efficiency for metals and color but were ineffective for ammonium. Instead, both zeolites demonstrated efficient ammonium removal (~50%) but were less efficient for metals, reflecting the mechanism-driven selectivity of the adsorbents studied. Finally, a principal component analysis (PCA) revealed correlations between biochar physicochemical properties and contaminant retention, providing insight into key factors governing adsorption and informing the design of sustainable leachate treatment strategies.

Linear α-olefins are important feedstocks in industry, and the critical challenge of their production lies in the separation of multicomponent α-olefins/paraffins. Currently, most research focused on binary α-olefin/paraffin systems, and the lack of understanding about the multicomponent α-olefins/paraffins hinders the development of adsorption technologies. Here, we investigated the competitive adsorption behavior of C6–C8 α-olefins/paraffins based on 13X zeolites, and it exhibited preferential adsorption toward 1-hexene, 1-heptene, and 1-octene than corresponding paraffins, as evidenced by the batch adsorption experiments and pulse experiments. To balance the competitive adsorption behavior among α-olefins, the mixed desorbent of 1-decene/n-decane was designed to realize the separation with optimized separation resolutions of α-olefins/paraffins and olefins. A 16-column simulated moving bed process was established guided by the pulse experiments on a scale-up column, and 99% purity C6–C8 α-olefins with 99% yield were obtained. This work reveals an energy-efficient adsorption process for C6–C8 α-olefins and paraffins with potential industrial use.

Study on near-infrared high reflectivity blue pigments based on 13X zeolite

Durable, hydrophobic and porous zeolite 13X coatings for resisting liquid water during CO2 desorption

Carbon capture and storage (CCS) technologies are an important step to mitigate CO2 emissions. This study focuses on CO2 capture from biomass combustion in fluidized bed boilers using a vacuum pressure swing adsorption (VPSA) process. A pilot-scale VPSA unit was used to evaluate the dynamic adsorption behavior of zeolite 13X and clinoptilolite under realistic operating conditions. Moreover, a simplified one-dimensional isothermal mathematical model of a fixed-bed adsorption column was developed to simulate breakthrough curves to validate whether the model reproduces the observed experimental trends. Experimental results confirmed that fresh zeolite 13X exhibited the highest CO2 adsorption capacity, while clinoptilolite showed moderate uptake. For both sorbents, a decrease in derived adsorption capacity was observed after prior use. The developed mathematical model successfully reproduced the experimental breakthrough curves, achieving coefficients of determination (R2) up to 0.99 and percentage fit (%Fit) values close to 94% for fresh sorbents, while lower correlations were observed for used sorbents. The model reliably captured the breakthrough curves, validating its applicability for process prediction. These results highlight the effectiveness of combining experimental measurements with modeling to assess sorbent performance and guide further optimization of VPSA processes under realistic flue gas conditions.

A novel sustainable synthesis strategy for producing a range of structurally distinct zeolites, specifically Zeolite 4A, Zeolite 13X, and Zeolite Y, is presented. This method avoids organic templates (commonly used for many high-silica zeolites such as ZSM-5, Beta, or high-silica Y) and directly produces Zeolite 4A, Zeolite 13X, and Zeolite Y from natural bentonite clay without the need for synthetic silica or alumina sources and thus offers a much more environmentally-benign production strategy than existing commercial synthetic routes. By systematically tuning alkaline fusion conditions and hydrothermal crystallization parameters, selective zeolite phase formation is achieved: lower fusion temperatures and NaOH/clay ratios favor the formation of LTA-type Zeolite 4A, while higher values promote the formation of FAU-type Zeolite 13X and Zeolite Y. The synthesized zeolites demonstrated structural characteristics and adsorption performance comparable to their commercial counterparts. Zeolite 13X exhibited the highest CO2 adsorption capacity, attributed to its elevated microporosity and sodium content, while Zeolite Y showed enhanced hydrothermal stability and reduced water affinity, resulting from its higher Si/Al ratio and lower cation density. Water vapor adsorption isotherms and repeated cycling tests revealed clear differences in hydrothermal stability between the synthesized zeolites. A cradle-to-gate life cycle assessment (LCA), performed for Zeolite 13X as a representative product, revealed a ∼90% reduction in global warming potential (2.48 vs. 24.25 kg CO2 eq. per kg), over 95% lower cumulative energy demand, and significantly decreased ecotoxicity and human toxicity indicators when compared to conventional chemical synthesis. Additionally, cost-oriented economic analysis showed that the clay-based synthesis route reduces the production cost of Zeolite 13X by approximately 33% compared to conventional chemical synthesis. Overall, this work provides a mechanistically informed, environmentally friendly framework for the phase-selective synthesis of industrially relevant zeolites from natural clay.

Experimental evaluation of zeolite 13X and activated carbon as adsorbents in a carbon capture system for ICE exhaust gases

Effect of humidity on microwave-based direct air capture under fluidization.