Search Results (145)

Thermoplastic polyurethane (TPU) electrospun fiber membranes possess unique micro-nano structures and excellent properties. Adjusting their wettability enables the directional transportation of lubricants. A conventional method for adjusting porosity and wettability involves inducing membrane shrinkage using absolute ethanol and heat treatment. However, the shrinkage response and the corresponding changes in the tensile properties of TPU fiber membranes after induction remain unclear, limiting their applications. Thus, in this study, after being peeled off, the samples were first left to stand at room temperature (RT) for 24 h to release residual stress and stabilize their dimensions, and then treated with dehydrated ethanol at RT and high temperature, respectively, with their shrinkage behaviors observed and recorded. The results showed that TPU nanofiber membranes shrank significantly in absolute ethanol, and the degree of shrinkage was temperature-dependent. The shrinkage rates were 2% and 4% in dehydrated ethanol at room temperature and high temperature, respectively, and heating increased the shrinkage effect by 200%. These findings prove that absolute ethanol causes TPU fibers to shrink, and high temperatures further promote shrinkage. However, although the strong synergistic effect of heat and solvent accelerates shrinkage, it may induce internal structural defects, resulting in the deterioration of mechanical properties. The contraction response induced by anhydrous ethanol stimulation can be used to directionally adjust the local density and modulus of TPU nanofiber membranes, thereby changing the wettability. This approach provides new opportunities for applications in areas such as medium transportation and interface friction reduction in lubrication systems. Full article

This study presents the first combined techno-economic and environmental analysis of IPA dehydration using HybSi^® membranes across three configurations, offering a low-emission alternative to conventional azeotropic distillation. The processes are simulated in Aspen Plus, and include two hybrid separation processes (i.e., distillation–pervaporation and distillation–pervaporation–distillation) and one standalone pervaporation process. The pervaporation module uses data from experiments that were performed using HybSi^® AR membranes at 130 °C and two vacuum pressures (20 and 50 mbar). The separation processes were systematically compared using a comprehensive set of performance indicators covering technical, economic, and environmental aspects. A new cost-efficiency metric, COPCO, is introduced, alongside updated modeling under 2024 market conditions. The isopropanol recovery and water selectivity were >99.5% and >98.7%, respectively, in all pervaporation-based processes. It was found that the hybrid distillation–pervaporation process resulted in a 42% reduction in the levelized cost of the benchmark azeotropic distillation process, while standalone pervaporation resulted in a 38% reduction. The CO₂ footprint was also reduced significantly in all cases, up to 86% in the case of standalone pervaporation compared to azeotropic distillation. The COPCO analysis revealed that the distillation–pervaporation configuration offers the highest cost-efficiency among the evaluated systems. Sensitivity analysis revealed that feed flow rate, average water flux, membrane module price, membrane lifetime, and steam price significantly impact the levelized cost. Lower vacuum pressure and feed water near the azeotropic composition enhance economic performance. Full article

Furfural is a fascinating bio-based platform molecule that can be converted into useful cyclic compounds, among others. In this work, the hydrogenative rearrangement-dehydration of furfural towards cyclopentanone using a commercially available Pt/C catalyst was investigated in terms of its reaction performance to assess its feasibility as an industrial process. However, acquiring an acceptable cyclopentanone yield proved very difficult, and the reaction was constrained by unforeseen parameters, such as the relative liquid volume in the reactor and the substrate concentration. Most strikingly, the sacrificial formation of furanoic oligomers that precipitated onto the catalyst’s surface was a troublesome key factor that mediated the product’s selectivity versus the carbon mass balance. By applying a biphasic water–toluene solvent system, the yield of cyclopentanone was somewhat improved to a middling 59%, while tentatively positive distributions of reaction components over these solvent phases were observed, which could be advantageous for anticipated down-stream processing. Overall, the sheer difficulty of controlling this one-pot cascade transformation towards a satisfactory product output under rather unfavorable reaction parameters renders it unsuitable for industrial process development, and a multi-step procedure for this chemical transformation might be considered instead. Full article

In recent decades, the attention of researchers has been directed towards the study of the dehydration of isopropanol (IPA) through different techniques. Besides its multiple uses in the chemical industry, IPA is also a potential bio-component in eco-friendly gasolines. Extractive distillation is a successful technique for separating IPA from a minimum boiling azeotrope with water. However, the major challenge is the production of fuel-grade IPA (minimum 99.92 mol%) with low expenses. As a consequent step in the investigation of IPA dehydration with propylene glycol as extractive solvent, the present study compares its efficiency and economic viability with two other extractive solvents, namely ethylene glycol (EG) and dimethyl sulfoxide (DMSO). A systematic and comprehensive methodology was developed to design a three-column extractive distillation (TCED) for each investigated solvent. A techno-economic assessment of all the investigated processes concluded that ethylene glycol, followed by propylene glycol, seems to be the most promising solvent in the IPA dehydration process. Further, the heat integration of hot streams (SH flowsheets) demonstrated improvements over 17% in the case of ethylene glycol solvent, around 16% in the case of propylene glycol (PG) solvent, and only 10% (in the case of DMSO solvent) reduction in utility consumption, improving the energy efficiency of TCED processes. Furthermore, SH flowsheets yield a 14% cost saving obtained in terms of total annualized cost (TAC) and, respectively, 8.69%, by comparison with TCED processes. In the case of DMSO solvent, the TAC reduction is only 3.54% due to the capital cost, which has an increase of 3% mainly due to the high solvent cost. Full article

Conventional mild hydrotreatment processes of bio-oil present significant challenges of a high degree of polymerization, a low oil yield, high coke formation, and poor catalyst recovery. To address these challenges, the current study looked into investigating and enhancing the properties of raw bio-oil organic phase samples via a solvent-assisted stabilization approach using methanol (METH), ethanol (ETH), isopropyl alcohol (IPA), and ethyl ether (DME). Solvents like methanol (METH) and ethanol (ETH), which are highly polar, yielded higher oil fractions (64% and 62%, respectively) compared to less polar solvents like ethyl ether (DME) at 59%. Isopropyl alcohol (IPA), with intermediate polarity, achieved a balanced oil yield of 63%, indicating its ability to dissolve both polar and non-polar components. Moisture reduction in stabilized bio-oils followed the order IPA > ETH > METH > DME, with IPA showing the highest reduction due to its structural characteristics facilitating dehydration. Viscosity reduction varied, with IPA > ETH > DME > METH. Carbon recovery in stabilized bio-oils ranged from 65% to 75% for DME, ETH, and METH and was 71% for IPA. The heating values of stabilized bio-oils ranged from 28 to 29 MJ/kg, with IPA-stabilized bio-oil showing the highest value (29.05 ± 0.06 MJ/kg). METH demonstrated high efficiency (74.8%) in stabilizing bio-oil, attributed to its strong hydrogen-donating capability. ETH followed closely at 69.5%, indicating its comparable performance in bio-oil stabilization. With moderate efficiency (69.3%), IPA presents a balanced alternative considering its molecular structure and hydrogen solubility. In contrast, DME exhibited lower efficiency (63.6%) due to its weaker hydrogenation capability and propensity for undesired side reactions. The current study suggests that subcritical conditions up to 200 °C are adequate for METH, ETH, and IPA in bio-oil stabilization, comparable to results obtained under supercritical conditions. Full article

In this work, the method of highly efficient conversion of l-rhamnose to 5-methylfurfural (MF) catalyzed by various catalysts in a biphasic system was developed. To enhance the MF yield, the effects of the catalyst species, reaction temperature (150–180 °C), extraction solvents and volume ratio of the extraction to the aqueous phase (0–5) on the conversion of l-rhamnose to MF were systematically investigated. Under optimal conditions, a high MF yield of 94% was achieved in the biphasic “diisopropyl ether (DIPE) + H₂O” system due to the fact that the extraction of MF to the DIPE phase significantly inhibits the condensation and degradation of MF in water. Finally, detailed reaction energetics and chemical structures of intermediates of the l-rhamnose dehydration to MF were investigated using the B3LYP level of theory and the SMD solvation model. It is evident that MF, which exhibits excellent chemical stability, harbors the potential to function as a bio-derived platform chemical within the domain of the green industry. Full article

Glucose is the most abundant monosaccharide as it is the primary unit of cellulose and starch, which are the more relevant feedstocks for biorefineries. Dehydration of glucose can lead to anhydroglucoses, whose interest has been increasing due to its potential industrial use. Commercial sulfonic polymer resins and a synthesized organic–inorganic mesoporous material were taken as Brønsted acid catalysts. High hexose conversion (up to 98%) and selectivity to anhydroglucoses (~80%) could be reached, turning this process into an alternative route to carbohydrate pyrolysis that presents an energy-intensive downstream. Hexose conversion to anhydroglucoses was related to the amount of acid sites, and the removal of one molecule of water from hexoses to produce anhydroglucoses was found as the preferential dehydration route over a bare Brønsted acid catalyst in anhydrous polar aprotic solvent (DMF) at mild conditions. Product distribution changed dramatically upon catalyst deactivation with HMF and fructose emerging as relevant products. It was suggested that an additional Lewis surface is produced during the deactivation process, probably arising from the formation of insoluble high molecular weight compounds in acidic media. Full article

Aging involves progressive physiological changes, including the dysregulation of water homeostasis, essential for cellular function, neuronal signaling, and musculoskeletal integrity. This review explores the emerging role of water loss as a central and underestimated driver of functional decline in aging, with a focus on the dog, both as a clinically relevant target species and as a model for human aging. Age-related alterations in water metabolism—driven by changes in body composition, aquaporin (AQP) expression, electrolyte imbalances, reduced thirst perception, and impaired urine concentration—lead to intracellular and extracellular dehydration, exacerbating functional decline. We examine molecular mechanisms of water regulation involving AQPs and osmolytes, and describe how dehydration contributes to structural and metabolic dysfunction across key biological compartments, including the kidney, brain, bone, and skeletal muscle. Physiological dehydration, a hallmark of aging, intensifies inflammaging, accelerating tissue degeneration. In particular, we highlight how water loss impairs solvent capacity, solute transport, protein conformation, and cellular communication. Despite the known role of macronutrients in geriatric nutrition, hydration remains an often-overlooked factor in aging management. We argue for its inclusion as a fourth pillar in the nutritional approach to veterinary geriatrics, alongside protein, fat, and fiber. By investigating aging-associated water loss in dogs—species that share environments and lifestyle patterns with humans—we propose hydration-centered strategies to promote healthy aging in both veterinary and comparative medicine. Full article

Ion-conductive gels (ICGs) are essential for achieving human–machine interfaces, bioelectronic applications, or durable wearable sensors. However, traditional solvent-dependent ICGs face bottlenecks such as dehydration-induced failure and challenges in achieving a balance between conductivity and mechanical properties. Here, this work developed a novel ternary ion-conductive xerogel (PEM-Li ICXG) system based on polyethylene glycol (PEG), poly (2-methoxyethyl acrylate) (PMEA), and LiTFSI. PEM-Li ICXGs exhibit high conductivity (2.7 × 10⁻² S/m), high adhesive capability (0.34 MPa), and solvent-free characteristics. Remarkably, the incorporation of ions into ICXGs simultaneously optimizes their mechanical performance. We demonstrate the application of ICGs in flexible sensors for strain or temperature sensing. The proposed synthesis strategy is straightforward and may further inspire the design of novel high-performance ICXGs. Full article

Haskap (Lonicera caerulea) berry is rich in anthocyanins, particularly cyanidin-3-O-glucoside (C3G). In this investigation, a response surface methodology was applied to optimize the anhydrous ethanol-based extraction parameters to obtain the maximum yield of anthocyanins from haskap berry and to compare the recovery of anthocyanins from different extraction methods. The central composite design was employed to study the effect of three independent variables (X_A = ultrasonic bath power, X_B = extraction temperature, and X_C = extraction time) which were found to significantly affect the response variable total anthocyanin content (TAC) and fit to the second-order polynomial model. The optimum process parameters of X_A = 536 W, X_B = 62.3 °C, and X_C = 63.5 min provided a predicted TAC of 16.5 mg C3G equivalence (C3GE)/g dry weight (DW), which was experimentally validated with 16.1 mg of C3GE/g DW. The optimized ultrasonication-assisted extraction process using anhydrous ethanol was also effective in recovering quercetin glycosides, catechin, procyanidin B2, and iridoids, as determined by ultra-pressure liquid chromatography–mass spectrometry. Though the anthocyanin recovery was the highest (17.6 mg of C3GE/g DW) when a deep eutectic solvent consisting of citric acid and D-(+)-maltose was used, this solvent system has limitations when preparing dehydrated extracts for industrial applications. This study concludes that the effective extraction of anthocyanins and other phytochemicals from haskap berries can be performed using food-grade anhydrous ethanol. Full article

In this paper, modified HZSM-5 catalysts with different ratios of chromium (Cr/HZSM-5) were synthesized and the solvent effect of gamma valerolactone (GVL) on the enhancement of levulinic acid (LA) yield was investigated. Characterization of the Cr/HZSM-5 catalyst revealed that the introduction of Cr did not change the structure of HZSM-5. The LA yield was increased from 42.5% (H₂O solvent system) to 51.4% (GVL/H₂O solvent system) under optimal conditions. The influence of GVL on the reaction mechanism was investigated through kinetic analysis, revealing that the incorporation of GVL reduces the activation energy barrier for the conversion of glucose to LA, thereby enhancing the glucose dehydration process. The effect of GVL on the product (LA) was studied, based on molecular dynamics. It was found that the addition of GVL squeezes the water in the solvent system into the second solvation shell layer, which causes GVL to distribute around the carbonyl, hydroxyl, and carboxyl groups of LA, and reduces the likelihood of LA side reactions, thus increasing the yield of LA. Full article

This study presents a novel approach to the dehydration of n-propanol using three hybrid methods—D + HPV, D + HPV + D, and D + HPV + D with heat integration—each combining distillation (D) and hydrophilic pervaporation (HPV) without the use of additional solvent agents, as in the most common separation method, extractive distillation. The optimization was performed using a ChemCAD process simulator, targeting 99.9 wt% purity for n-propanol and water. This is the first research to provide a comprehensive cost estimation and carbon footprint analysis for such configurations. Results show the D + HPV + D + HI method provides the best balance of energy efficiency, environmental sustainability, and economic feasibility. It reduced heat duties by 18.5% compared to D + HPV + D, achieved similar CO₂ emissions to D + HPV with better energy efficiency, and lowered the total annual cost by 37.9% compared to D + HPV. The findings establish D + HPV + D + HI as a promising technology for sustainable and cost-effective n-propanol dehydration. Full article

CO₂ is the main solvent used in enhanced oil recovery (EOR). However, its low density and viscosity compared to oil cause a decrease in sweep efficiency. Recently, dimethyl ether (DME), which is more efficient than CO₂, has been introduced into the process. DME improves oil recovery by reducing minimum miscible pressure (MMP), interfacial tension (IFT), and oil viscosity. Since DME is an expensive solvent, price reduction and appropriate injection scenarios are needed for economic feasibility. In this study, a compositional model was developed to inject DME with impure CO₂ streams, where the CO₂ was derived from one of these three purification methods: dehydration, double flash, and distillation. It was assumed that such a mixed solvent was injected into a heterogeneous reservoir where gravity override was maximized. As a result, lower oil recovery is achieved for the higher impurity content of the CO₂ stream, lower DME content, and more heterogeneous reservoir. When a high-purity CO₂ stream is used, the change in oil recovery according to DME content and heterogeneity of the reservoir is increased. When the lowest-purity CO₂ stream is used, the net present value (NPV) is the highest. For a homogeneous reservoir, the NPV is highest for all impure CO₂ streams. This optimization indicates a greater impact on revenue from reduced CO₂ purchase cost than on profit loss due to reduced oil recovery by impurities. Additional benefits can be expected when considering solvent reuse and carbon capture and storage (CCS) credits. Full article

NbVO_x mixed oxides were synthesized, characterized, and evaluated as catalysts for the extractive catalytic oxidative desulfurization (ECODS) of dibenzothiophene (DBT) using acetonitrile as a solvent. The mixed oxides were prepared using two different vanadium precursors: ammonium metavanadate and vanadium(IV)-oxy acetylacetonate. These precursors influenced the acidic/basic properties and the concentration of oxygen vacancies in the resulting catalysts. The texture and surface properties of the synthesized materials were analyzed using nitrogen adsorption/desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–visible spectroscopy (UV-vis). Their catalytic activity was evaluated through the dehydration and dehydrogenation of 2-propanol and the ECODS of DBT. The mixed oxides synthesized with an excess of ammonium metavanadate (Nb:V = 1:2) demonstrated superior catalytic activity in removing DBT from the oil phase, achieving approximately 90% removal within 90 min at 60 °C. This enhanced activity is attributed to its higher acidity, greater concentration of oxygen vacancies, and the presence of vanadium peroxo ligands on its surface. Full article

Efflorescence, a time-dependent and water-driven phenomenon, is a major concern in alkali-activated materials (AAMs), impacting their practical use and preservation in a time-frozen state for post-characterisation. Although a method for stopping chemical reactions in conventional cements exists, it is time-consuming and not chemical-free. Therefore, this study explored the effects of low-power microwave-induced dehydration on efflorescence, mechanical performance, and structural integrity in AAMs, to create an alternative and more “user-friendly” dehydration method. For this purpose, several mixtures based on secondary raw (slag, fly ash, glass wool, and rock wool) and non-waste (metakaolin) materials were activated with a commercial Na-silicate solution in ratios that promoted or prevented efflorescence. Characterisation techniques, including Fourier-transform infrared spectroscopy and X-ray diffraction, showed that microwave dehydration effectively removed water without altering crystallinity, while mercury intrusion porosimetry and compressive strength tests confirmed increased porosity. In addition to being an efficient, time-saving, and solvent-free manner of stopping the reactions in AAMs, microwave irradiation emerged as an innovative, chemical-free method for evaluating curing finalisation and engineering foams in a stage when all other existing methods fail. However, the artificially provoked efflorescence in aged dehydrated AAMs connected the slipperiness of AAM with the instant extraction of Na, which raised the need for further research into alternative alkali replacements to evaluate the practical use of AAM. Full article