Aluminum Fumarate Research Articles

Ligand extension of aluminum fumarate metal-organic framework in transferring higher water for adsorption desalination

This article presents the synthesis and characterization of a new microporous metal organic framework (MOF) for adsorption desalination for the first time. The new MOF, designated as “Al-t,t-Ma”, is an analogue of aluminum fumarate (Al-Fum) and is fabricated via ligand extension method. Firstly, the MOF is synthesized, and then characterized by XRD, FTIR spectroscopy, TEM, SEM, TGA and N2 adsorption techniques. Secondly, the water adsorption experiments on the pristine Al-Fum and Al-t,t-Ma are performed for a wide temperature (30 °C ≤ T ≤ 80°C) and pressure (0 < P/Ps ≤ 0.9) ranges. The water adsorption isotherms, kinetics, hydro-thermal stabilities as well as the isosteric heat of adsorption (Qst) are evaluated. Thirdly, based on the experimentally confirmed isotherms, kinetics and isosteric heats data, the adsorption assisted desalination (AD) system is modelled and simulated. Finally, the performances of AD system employing Al-Fum and Al-t,t-Ma MOFs are calculated in terms of the performance ratio (PR) and specific daily water production (SDWP) under various half cycle times (100 s ≤ tcycle ≤ 1000 s) and regeneration temperatures (55°C ≤ Tregen ≤ 80°C). As compared with the pristine Al-Fum, the pore volume of Al-t,t-Ma MOF is found 115 % higher. The proposed Al-t,t-Ma MOF possesses higher water transfer (+57.5 % more) with promising hydro-thermal stability. Employing Al-t,t-Ma MOF as porous adsorbent, the SDWP is achieved 28 m3 per tonne of MOFs per day at the regeneration temperature of 55°C. These results confirm that Al-t,t-Ma MOF is a competent candidate for adsorption desalination.

Green composite synthesis based on aluminum fumarate metal-organic framework (MOF) for doxorubicin delivery: An in vitro study

The development of an eco-friendly and cost-effective drug delivery system (DDS) remains a challenge in cancer treatment. This study suggests a novel, eco-friendly, and cost-effective method to synthesize aluminum fumarate (A520) MOF using tangerine peel extract (TPE) as a pH-sensitive coating agent on a reduced graphene oxide (rGO) substrate. The system also incorporates the 2,2′-bipyridine dimethyltin diisothiocyanate complex, (Sn(bpy), as an organotin complex) to enhance therapeutic efficacy while minimizing off-target effects. In vitro cellular and molecular cytotoxicity examinations were conducted using HEK-293 and MCF-7 cell lines to evaluate cytotoxicity after 24 and 72 h. The findings of the MTT assay indicated that the final nanocarriers, without and with doxorubicin (DOX), exhibited relative cell viability of 95 % and 55 %, respectively, highlighting the system's potential for efficient and safe drug delivery. The TPE coating created a pH-sensitive DDS with high drug loading efficiency (DLE) (59.1 %) and low cytotoxicity. Drug release was studied over 200 h at pH 5.5 and 7.2. The augmented drug release profile (47 %) demonstrated a targeted release and successful inhibition of premature release in acidic environments due to pH-sensitive TPE molecules. The efficacy of targeted drug delivery to the MCF-7 cell was evaluated using 2D fluorescence microscopy, which demonstrated successful delivery of drugs to the cells. This innovative approach addresses the limitations of existing studies while promoting biocompatibility, stability, and functionality in DDSs.

Novel MOF-303/G coated wire-finned heat exchanger for dehumidification applications–Experimental investigation

Adsorption dehumidification outperforms other technologies regarding moisture removal rate, lower energy consumption, and environmental friendliness. The selection of desiccant material, the heat exchanger used, and the method of regeneration significantly impact the performance of desiccant dehumidifiers in terms of water vapour removal rate and energy consumption. Metal-organic framework materials are a new class of microporous materials with high water adsorption characteristics compared to conventional desiccants like silica gel. In this work, a novel MOF-coated electrically heated wire finned heat exchanger was developed, and its performance was experimentally investigated. Wire-finned tubes coated with MOF-303/G outperformed other wire-finned tubes coated with Aluminium fumarate, MIL-100(Fe), MIL-100(Fe)/G, MOF-801 and MOF-801/G, achieving water uptake of 22 %. Also, the addition of graphene nanoplatelets during the synthesis of MOF-303 resulted in a significant enhancement of its thermal diffusivity to reach 0.184–0.23 mm2/s at temperatures ranging between 25 °C and 115 °C. The Coefficient of Performance (COP) for the developed multi-tube MOF-303/G coated heat exchanger was experimentally tested and compared to other desiccant-coated heat exchangers. Results showed that COP values ranging from 0.6264 to 1.02 to 1.2 at the regeneration temperatures of 45 °C, 60 °C and 70 °C, respectively, were achieved, which are higher than those reported in the literature.

Heat and mass transfer analysis of desiccant-coated heat exchanger with desiccants and metal-organic framework for bus air conditioning applications

Desiccant-coated heat exchangers (DCHEs) in air conditioning offer advantages like independent temperature and humidity control, reduced energy consumption, and high performance. However, the availability of desiccants with high water adsorption and low thermal energy requirements is limited. The present study proposes that aluminum fumarate (Al-Fum) MOF-coated heat exchangers will outperform conventional desiccants, especially at low regeneration temperatures (around 50°C). In order to evaluate this hypothesis, the performance of DCHEs was evaluated with a validated analytical model for different solid desiccant coatings: silica gel, zeolite, and Al-Fum MOF. Water vapor sorption characteristics, heat and mass transfer, and adsorption and desorption capacities were determined. The results showed that the Al-Fum MOF-coated heat exchanger outperformed silica gel and zeolite at low regeneration temperatures under adiabatic conditions. The MOF exhibited superior water uptake capacity (0.39 g/g) between 20% and 80% RH compared to the other studied conventional desiccants. Moreover, the MOF achieved the lowest outlet air temperature. At 19.5 g/kgda, the MOF demonstrated higher adsorption rates (4 % and 0.3 %) than zeolite and silica gel. These findings highlight the potential of Al-Fum MOFs as energy-efficient solutions for controlling indoor air humidity, particularly for latent-sensible heat separation systems with conventional vapor compression bus air-conditioning systems.

Radiation resistant metal–organic frameworks for the production of high specific activity 51Cr by the Szilard-Chalmers effect

Chromium-51 (51Cr) is an attractive radionuclide for diagnosis, which is usually applied for red cells and platelet radiolabeling. However, commercially available 51Cr produced in nuclear reactors via neutron activation requires long irradiation times and complex separation methods. In this work, five metal–organic frameworks (MIL-100 (Cr), MIL-100 (Fe), MIL-100 (Al), MIL-101 (Cr) and aluminium fumarate MOF (FuAl)) were synthesized and the effect of gamma ray irradiation with a high dose rate and a maximum dose of 6 MGy was investigated. The two chromium-based MOFs, MIL-100 (Cr) and MIL-101 (Cr), were selected as radiation targets to produce high specific activity 51Cr by the Szilard-Chalmers effect. A solid–liquid extraction was applied to extract the produced 51Cr under different conditions, including different extractants, extraction times and pH. The most promising results were achieved when using irradiated MIL-101 (Cr) and EDTA as extracting agent, reaching an enrichment factor of 1132 ± 50.

Aluminium Fumarate MOF 적용 흡착식 냉동기의 기후 및 구동조건에 따른 성능분석

Aluminium Fumarate MOF 적용 흡착식 냉동기의 기후 및 구동조건에 따른 성능분석

Study of metal–organic framework (MOF)/water pairs for adsorption heat transformer applications

Metal-organic framework (MOF), an advanced category of porous coordination polymers, has recently gained prominence as a novel class of adsorbent materials, captivating the attention of researchers worldwide engaged in diverse applications related to adsorption. An adsorption heat lifter or adsorption heat transformer (AdHT) plays a crucial role in elevating the temperature of a waste heat source. This is achieved by harnessing the adsorption enthalpy or isosteric heat of adsorption. The system performance of the AdHT system is affected by the working pairs, which leads to a possible application for MOF/water working pairs in such a system. In this study, 2-tank and 3-tank systems are invoked to investigate and compare the coefficient of performances (COPs) of three MOFs: MOF–801, aluminum fumarate, and MIL–100(Fe) paired with water while considering an atmospheric temperature of 308.15 K. With a waste heat source and cooling water temperature difference (TD) of 70 K in the 3-tank system, MOF–801/water outperforms aluminum fumarate and MIL-100(Fe). Considering a temperature driving force that explains the temperature change of heat transfer fluid during the flowing procedure inside pipes, ΔT = 5 K, the MOF–801/water pair can provide a gross temperature lift of around 30 K at a relatively good COP of 0.4867. There are very few articles that studied the MOFs/water pair for AdHT 2-tank and 3-tank system applications. Hence, the results of this study highlight their viability for designing environmentally friendly and energy-efficient heating systems.

Sulfate ion induced formation of unsaturated coordination of AlF3 nanocluster catalyst confined in carbon framework for catalytic dehydrofluorination

The gas-phase catalytic dehydrofluorination of hydrofluorocarbons (HFCs) to produce hydrofluoroolefins is an important strategy for the resource utilization of HFCs. AlF3 is the most suitable and efficient catalyst for dehydrofluorination of HFCs. However, sintering and preservation of coordinatively unsaturated aluminum centers pose significant challenges for AlF3 catalysts. Herein, we prepared carbon-confined AlF3 nanocluster catalysts with aluminum fumarate metal organic frameworks (AlFu-MOF) as the precursors, followed by carbonization and fluorination treatments. During catalyst preparation, anion ligand in the aluminum salt plays a major role in the formation of coordinatively unsaturated Al centers. Compared with Al(NO3)3·9H2O and AlCl3·6H2O, AlFu-MOF (named AlFu-S) prepared with Al2(SO4)3·18H2O exhibits a higher concentration of Al-OH species. Additionally, the residual SO42- ions can indeed retard the crystallization of AlF3 at elevated temperatures. Hence, the decomposition of Al-OH groups and the presence of residual SO42- ions in AlFu-S contribute together to the abundance of unsaturated coordinated Al centers in the finally carbon-confined AlF3 nanocluster catalyst (named AlFu-S-550-F). Also, the confinement effect of the carbon material formed by the carbonization of AlFu-S effectively prevent AlF3 nanocluster from sintering and phase transition, hence, in the dehydrofluorination of HFC-134a, AlFu-S-550-F demonstrates excellent stability compared to AlF3 catalysts prepared by precipitation methods. In summary, this study provides a strategy for the preservation of coordinatively unsaturated aluminum centers in AlF3 catalysts due to sintering and crystal structure transformation. Furthermore, the methodology proposed in this work is also applicable to the preparation of other coordinatively unsaturated metal catalysts.

A Functionally Asymmetric Janus Hygro-Photothermal Hybrid for Atmospheric Water Harvesting in Arid Regions.

Metal-organic frameworks (MOFs) are high-performance adsorbents for atmospheric water harvesting but have poor water-desorption ability, requiring excess energy input to release the trapped water. Addressing this issue, a Janus-structured adsorbent with functional asymmetry is presented. The material exhibits contrasting functionalities on either face - a hygroscopic face interfaced with a photothermal face. Hygroscopic aluminum fumarate MOF and photothermal CuxS layers are in-situ grown on opposite sides of a Cu/Al bimetallic substrate, resulting in a CuxS-Cu/Al-MOF Janus hygro-photothermal hybrid. The two faces serve as independent "factories" for photothermal conversion and water adsorption-desorption respectively, while the interfacing bimetallic layer serves as a "heat conveyor belt" between them. Due to the high porosity and hydrophilicity of the MOF, the hybrid exhibits a water-adsorption capacity of 0.161g g-1 and a fast adsorption rate (saturation within 52min) at 30% relative humidity. Thanks to the photothermal CuxS, the hybrid can reach 71.5 °C under 1 Sun in 20min and desorb 97% adsorbed water in 40min, exhibiting a high photothermal conversion efficiency of over 90%. CuxS-Cu/Al-MOF exhibits minimal fluctuations after 200 cycles, and its water-generation capacity is 3.21 times that of powdery MOF in 3 h in a self-designed prototype in one cycle.

An effective approach for CH4/N2 separation using aluminum-based metal-organic frameworks (MOFs) prepared from coal fly ash

Metal-organic frameworks (MOFs) are considered one of the promising adsorbents for CH4/N2 separation. However, MOFs commercialization is a big challenge since their synthetic materials are expensive and not environmentally friendly. Herein, the dealumination solution obtained from coal fly ash (CFA) using sulfuric acid as an extracting agent through direct leaching and roasting technologies was applied as metal feedstock to prepare CFAx-FumMOF-y and compared to aluminum fumarate MOF (Al-FumMOF) in morphology, surface area, micropore volume, and CH4/N2 selective separation. The results indicated that CFAx-FumMOF-y exhibited closely similar surface area (1164.94–1073.08 m2/g) and micropore volume (0.40–0.36 cm3/g) to Al-FumMOF (1287.55 m2/g, 0.42 cm3/g), even there were no detectable differences in CH4 uptakes (CFAx-FumMOF-y, 21.93–20.69 cm3/g; Al-FumMOF, 22.13 cm3/g) at 298 K and 1.0 bar, suggesting that the impurity metal species in dealumination solution hardly affect textural properties and gas uptakes. Moreover, the isosteric heat of adsorption (Qst) and IAST CH4/N2 selectivity of CFAs-FumMOF-1 (19.25–17.84 kJ/mol) and CFAb-FumMOF-1 (18.83–18.64 kJ/mol) were slightly superior to Al-FumMOF (17.83.64–16.86 kJ/mol, 4.87), suggesting that CFAx-FumMOF-1 played an identical role as Al-FumMOF in gases separation. The cyclic regeneration experiments and binary breakthrough tests further confirmed that CFAx-FumMOF-y was feasible for practical application. This study provides a new perspective for reducing the production cost of MOFs as well as realizing high-value utilization of CFA.

Aluminium fumarate biological metal–organic framework as an emerging tool for isolation and detection trace amounts of sulfadiazine in food and water samples

Owing to negative impacts of sulfadiazine (SDZ) as an important group of synthetic antibiotics on public health and ecological systems, it has been a serious concern in recent years. In this research, aluminium fumarate biological metal–organic framework (AlFum Bio-MOF) was synthesized and applied as the best option in terms of extraction performance for detection and quantification of SDZ in a variety of samples. The chemical/structural properties of as-prepared AlFum Bio-MOF were confirmed by spectroscopy techniques. The influence of pH, amount of adsorbent, ultrasonic time (adsorption time (and ionic strength as the main variables in the extraction process were optimized and inspected with central composite design (CCD). Linear dynamic range (LDR), the limit of detection (LOD), and precision value (expressed as relative standard deviation (RSD)) in selected conditions were 20–580, 5.67 ng mL−1, and 3.40 % (n = 3), respectively. The developed method was successfully applied for the determination of SDZ in different water and food samples at two spiked levels with recoveries between 84 and 104 %. Practically, the dispersive micro-solid phase extraction (Dμ-SPE) based on AlFum Bio-MOFs as sorbent could be used to quantify SDZ in complex matrices at trace amounts with acceptable recoveries.

Facile synthesis of Aluminium fumarate metal–organic framework and hydroxyapatite composite with improved adsorption characteristics for efficient fluoride removal from water

An aluminium fumarate (AlFu)-hydroxyapatite (HAP) composite (AlFu-HAP) with numerous functional groups for fluoride binding was synthesised by a simple solid–solid mixing process. The produced AlFu-HAP composite with numerous functional groups results in outstanding adsorption capability in the sequence AlFu-HAP > AlFu > HAP. This composite was studied under different pH, initial fluoride concentrations, temperatures, and contact times. The adsorption kinetics and isotherms were pseudo-second-order model and Freundlich adsorption isotherm, respectively. XRD, SEM, FTIR, Raman spectroscopy, and XPS analysis of the samples before and after the adsorption reaction indicate that the fluoride removal mechanism was controlled by anion exchange of the OH– group in AlFu-HAP and F- in water. At high concentrations (150–200 mg F-/L) in groundwater and industrial effluent, the AlFu-HAP showed > 90 % fluoride removal. Thus, the current study will provide an effective strategy for developing an AlFu-HAP composite adsorbent to be used for the effective elimination of fluoride from wastewater.

Water, ethanol, or methanol for adsorption chillers? Model-based performance prediction from Infrared-Large-Temperature-Jump experiments

Adsorption chillers are a promising technology to ease the burden on renewable electricity demand by using waste heat as driving energy. Their performance depends on the adsorbent’s kinetics, the chosen refrigerant, the design of the adsorber, and the selected temperatures. Thus, quantifying an adsorption chillers’ performance usually requires expensive experiments at full scale. Here, we efficiently characterize a broad set of working pairs for a wide range of conditions using a two-step approach: First, we conducted Large-Temperature-Jump and equilibrium experiments to extract kinetic and equilibrium parameters of water, ethanol, and methanol with a set of currently discussed adsorbents. Second, we inserted the parameters into a dynamic Modelica model to evaluate the working pairs’ performance in full-scale two-bed adsorption chillers. For chilling above 0 °C, water remains the benchmark refrigerant with the highest volumetric power and efficiency with the silica gels SG123 and Siogel. Ethanol and methanol working pairs offer higher mass transfer coefficients, but could not offset the benefits of water. Coatings of the MOFs aluminum fumarate and CAU–10–H provided exceptionally high heat transfer coefficients, but were too thin to compete. For chilling below 0 °C, ethanol and methanol were on par. ZIF–8 was competitive with the activated carbon CarboTech A35. Overall, CarboTech A35/methanol showed broad applicability, performing comparably to SG123/water above 0 °C while still providing reasonable performance below 0 °C.

Thermodynamic Analysis and Performance Assessment of a Novel Solar-Based Multigeneration System for Electricity, Cooling, Heating, and Freshwater Production

Abstract This study offers a comprehensive assessment of the thermodynamic performance of a novel solar-based multigeneration system, which caters to the energy needs of a sustainable community by producing electricity, cooling, heating, and freshwater. The solar-based multigeneration system is comprised of four main components: the thermal subsystem of the parabolic trough collector (PTC) employing CO2 as a heat transfer fluid, a single-effect absorption refrigeration cycle (ARC), a supercritical CO2 (S-CO2) cycle, and an adsorption desalination (AD) cycle with heat recovery employing aluminum fumarate metal–organic framework (MOF) adsorbent material. A comprehensive parametric study was performed on the proposed solar-based multigeneration system by varying key parameters to evaluate its performance. It is found that the thermal and exergy efficiencies of a PTC were evaluated to be 68.35% and 29.88%, respectively, at a fixed inlet temperature of 225 °C and solar irradiation of 850 W/m2 and also a slight reduction in the ARC cycle when examining the variation in the thermal and exergetic COPs for the generator temperature. Additionally, the thermal and exergy efficiencies of electricity, cooling, and heating were determined to be 20.41% and 21.93%, 41.34% and 3.51%, and 7.14% and 3.07%, respectively, at the operating condition. The maximum specific daily water production (SDWP) value of 12.91 m3/ton/day and a gain output ratio (GOR) of 0.64 were obtained under steady operating conditions in the AD cycle.

Development and assessment of a novel integrated system powered by parabolic trough collectors for combined power, heating and freshwater production

Abstract Hybrid solar-based integrated systems represent a viable solution for countries with abundant solar radiation, as they provide energy needs in an environmentally friendly way, offering a sustainable and economically advantageous energy solution that utilizes a free source of energy. Therefore, this research offers a thermodynamic evaluation of a novel integrated system driven by solar energy that aims to produce power, heating and freshwater. The integrated system consists of a parabolic trough collector that uses CO2 as its working fluid and implements the supercritical carbon dioxide cycle to generate power and heating. The integrated system also includes an adsorption desalination system with heat recovery between the condenser and evaporator, which employs a cutting-edge material called an aluminium fumarate metal–organic framework to produce fresh water. For the modelling of a novel system, an engineering equation solver, which is considered a reliable tool for thermodynamic investigations, is employed. The effectiveness of an integrated system is evaluated using a mathematical model and different varying parameters are examined to ascertain their influence on thermal and exergy efficiency, specific daily water production and gained output ratio. The results revealed that the parabolic trough collector achieved a thermal efficiency of 67.2% and an exergy efficiency of 41.2% under certain conditions. Additionally, the thermal efficiencies for electrical and heating were obtained 24.68% and 9.85%, respectively. Finally, the specific daily water production was calculated, showing promising results and an increase from 7.1 to 12.5 m3/ton/day, while the gain output ratio increased from 0.395 to 0.62 when the temperature of hot water increased from 65°C to 85°C, under the selected conditions.

Enhanced photo-degradation of organic contaminants on CdS/magnetic aluminum fumarate metal-organic framework as a novel Z-scheme photocatalyst under visible light: A comprehensive study

In the current study, Fe3O4/aluminum fumarate (AlFu) magnetic nanocomposite has been synthesized through the sol-gel procedure to be used as a novel support for CdS nanorods in photocatalytic degradation of Congo red (CR) and crystal violet (CV) dyes in aqueous media under visible light irradiation, separately. The CdS nanorods were solvothermally decorated on magnetic AlFu. The physicochemical properties of the synthesized samples were examined by multiple techniques. In comparison to pure CdS, the photocatalytic performance of magnetical separable Cd/magnetic AlFu is striking. This could be attributed to improving the recombination rate, charge transfer resistance, and adsorption site, which are figured out through characterization data. Removal of contaminants has been statistically optimized and modeled based on operational parameters, including catalyst dosage, initial dye concentration, and pH. At optimum conditions, the removal of CR and CV dyes was 99.5 % and 86.17 %, respectively. Moreover, the photocatalyst exhibited satisfactory performance in TOC removal and remarkable stability during six successive cyclic operations. At several dye concentrations, kinetic experiments have been undertaken, and results revealed that the photo-degradation reaction of CR and CV corresponds well with the Langmuir-Hinshelwood model. Furthermore, the Z-scheme mechanism was suggested based on characterization data and quenching experiments, which revealed that •O2- plus h+ in CR photo-degradation, and •O2- plus •OH in CV photo-degradation play pivotal roles.

Enhanced Water Sorption Performance of Polyacrylamide & Glass Fiber Paper Composites: Investigation and Comparison of Application in Desiccant Wheels.

The water sorption and desorption properties of solid adsorbent materials are crucial in rotary dehumidification systems. Metal organic frameworks (MOFs) and hydrogels are mostly at the laboratory stage due to factors like the synthesis process and yield. In this study, we utilized an eco-friendly and large-scale synthesis method to prepare polyacrylamide (PAM) hydrogels (yielding approximately 500 mL from a single polymerization). Subsequently, PAM was then coated onto glass fiber paper (GFP), which serves as a commonly employed substrate in desiccant wheels. By incorporating the hygroscopic salt LiCl and optimizing the content of each component, the water sorption performance of the composite was notably improved. The water sorption and desorption performances, as well as cycling stability, were evaluated and compared with composites containing aluminum fumarate, LiCl, and GFP (AlFum-LiCl&GFP). The results revealed that PAM-LiCl&GFP outperformed AlFum-LiCl&GFP in terms of sorption capacity throughout various relative humidity (RH) levels. It achieved a water uptake of 1.06 g·g-1 at 25 °C and 30% RH, corresponding to a water sorption rate coefficient K of 15.32 × 10-4 s-1. Furthermore, the lower desorption temperature (60 °C) resulting in a desorption ratio of 82.6%, along with the excellent cycling stability and effective performance as a desiccant wheel module, provide evidence for the potential application of PAM-LiCl&GFP in desiccant wheels.

Novel proposal and assessment of a solar-powered supercritical CO2 cycle integrated with adsorption desalination system for electricity, heating and desalination

This paper presents a thermodynamic performance evaluation of a novel solar based supercritical CO2 (S-CO2) cycle and low temperature adsorption desalination (AD) cycle for power, heating, and freshwater. This novel technology utilizes molten salt as a medium for thermal energy transfer in the solar tower collector and generates power and heating by utilizing the S-CO2 cycle, as well as the AD cycle with heat recovery using aluminium fumarate material to produce freshwater. A parametric investigation is established in order to numerically assess the influence of different parameters on the performance parameters of the novel proposed system. Results show that the thermal efficiency of the solar tower receiver improves from 89.12% to 90.53%, when DNI rises from 900 W/m2 to 1100 W/m2. The thermal and exergy efficiencies of the S-CO2 power cycle are found to be higher at 1100 W/m2 and it is ranged from 33.4% to 44.81% and 54.2%–72.52% respectively, with the rise in inlet pressure of the expander from 12000 kPa to 18000 kPa. In addition, the thermal efficiency of electrical and heating was obtained 25.33% and 10.13%, respectively, at operating conditions. The highest SDWP was achieved 12.5 m3/ton/day and 0.62 GOR at a fixed operating condition.

Benchmarking metal-organic framework coatings from Large-Temperature-Jump experiments: Learning from trade-offs in mean powers versus characteristic times

Adsorption chillers can substitute the electric energy demand of conventional compression chillers with low-temperature heat. The efficiency and power density of adsorption chillers depend on their adsorbent and refrigerant, which form the working pair. Novel working pairs are therefore actively developed and characterized in dynamic small-scale experiments using a characteristic time constant. However, this evaluation by only few characteristic time constants, does not resolve the trade-off between efficiency and power density of adsorption chillers and novel materials are challenging to compare due to varying size, shape, and density. To fill these gaps, we investigate the trade-off between efficiency and power density by quantifying all characteristic time constants and transferring them to specific mean powers. We perform Large-Temperature-Jump experiments with water as the refrigerant on the two metal–organic frameworks CAU–10–H and aluminum fumarate for a chilling/recooling/regeneration temperature triple of 10/30/80 °C. We compare the metal–organic frameworks’ specific mean powers to the commercially available RD type silica gels Siogel and SG123. Siogel performed best in terms of area-specific mean powers with a maximum value of 3.2 kW/m². For low time constants up to 20% relative loading, corresponding to high power density but lower efficiency, Siogel also provided the highest volume-specific mean power at 8.1 MW/m³. CAU–10–H had the highest mass- and volume-specific mean powers at 19.0–19.9 kW/kg and 7.2–8.6 MW/m3 for characteristic time constants of 35% relative loading and higher. Aluminum fumarate and SG123 showed low specific mean powers for all chosen characteristic time constants. The results show that studying specific mean powers is a useful tool to benchmark adsorption working pairs as they would perform in an adsorption chiller, regardless of mass, shape, or density.

Is There Any Benefit of Coating Si Particles for a Negative Electrode Material for Lithium-Ion Batteries with Metal–Organic Frameworks? The Case of Aluminum Fumarate

Is There Any Benefit of Coating Si Particles for a Negative Electrode Material for Lithium-Ion Batteries with Metal–Organic Frameworks? The Case of Aluminum Fumarate