Water Removal Process Research Articles

Geothermometrical calculations of thermal waters affected by secondary processes: The case of Sierra Elvira (Spain)

Geothermometrical calculations in thermal systems are often limited by the presence of secondary processes that modify the chemistry of the deep reservoir fluid during the ascent to the surface (e.g., mixing, degasification). The effect of secondary processes can be avoided by applying some techniques to reconstruct the chemical equilibrium at depth and the fluid original composition. However, the reconstruction of thermal waters mixed with cold surficial waters is complicated when the dilution factors are unknown. For that case, here, we propose to use an approach consisting of the simulation of a concentration process that removed different amounts of water from the thermal solutions until the equilibrium temperatures of anhydrite and quartz converge for the waters affected by mixing in unknown proportions. Using classical geothermometers and geothermometrical modeling, including the water removal process and CO2 degasification, a temperature range of 78 ± 9 °C at depth has been established for the Sierra Elvira geothermal system whose waters are in chemical equilibrium with respect to calcite, dolomite, anhydrite, quartz, illite, pyrophyllite and beidellite-K. The good agreement in the temperatures obtained for the different thermal fluids of the system suggests a common reservoir for all of them. The methodology used in this study can be applied to other geothermal systems in carbonate rocks affected by mixing.

Development of Robust Freeze-Drying Process for Long-Term Stability of rVSV-SARS-CoV-2 Vaccine.

The thermostability of vaccines, particularly enveloped viral vectored vaccines, remains a challenge to their delivery wherever needed. The freeze-drying of viral vectored vaccines is a promising approach but remains challenging due to the water removal process from the outer and inner parts of the virus. In the case of enveloped viruses, freeze-drying induces increased stress on the envelope, which often leads to the inactivation of the virus. In this study, we designed a method to freeze-dry a recombinant vesicular stomatitis virus (VSV) expressing the SARS-CoV-2 spike glycoprotein. Since the envelope of VSV is composed of 50% lipids and 50% protein, the formulation study focused on both the protein and lipid portions of the vector. Formulations were prepared primarily using sucrose, trehalose, and sorbitol as cryoprotectants; mannitol as a lyoprotectant; and histidine as a buffer. Initially, the infectivity of rVSV-SARS-CoV-2 and the cake stability were investigated at different final moisture content levels. High recovery of the infectious viral titer (~0.5 to 1 log loss) was found at 3-6% moisture content, with no deterioration in the freeze-dried cakes. To further minimize infectious viral titer loss, the composition and concentration of the excipients were studied. An increase from 5 to 10% in both the cryoprotectants and lyoprotectant, together with the addition of 0.5% gelatin, resulted in the improved recovery of the infectious virus titer and stable cake formation. Moreover, the secondary drying temperature of the freeze-drying process showed a significant impact on the infectivity of rVSV-SARS-CoV-2. The infectivity of the vector declined drastically when the temperature was raised above 20 °C. Throughout a long-term stability study, formulations containing 10% sugar (sucrose/trehalose), 10% mannitol, 0.5% gelatin, and 10 mM histidine showed satisfactory stability for six months at 2-8 °C. The development of this freeze-drying process and the optimized formulation minimize the need for a costly cold chain distribution system.

Scleroglucan-Based Foam Incorporating Recycled Rigid Polyurethane Waste for Novel Insulation Material Production.

This study details the synthesis and performance evaluation of a novel lightweight thermal and acoustic insulation material, resulting from the combination of a scleroglucan-based hydrogel and recycled rigid polyurethane waste powder. Through a sublimation-driven water-removal process, a porous three-dimensional network structure is formed, showcasing notable thermal and acoustic insulation properties. Experimental data are presented to highlight the material's performance, including comparisons with commercially available mineral wool and polymeric foams. This material versatility is demonstrated through tunable mechanical, thermal and acoustic characteristics, achieved by strategically adjusting the concentration of the biopolymer and additives. This adaptability positions the material as a promising candidate for different insulation applications. Addressing environmental concerns related to rigid polyurethane waste disposal, the study contributes to the circular economy.

Experimental study and machine learning modeling of water removal efficiency from crude oil using demulsifier

This study deals with the investigation of the water removal efficiency (WRE) from crude oil using a commercial demulsifier. The impacts of time, demulsifier concentration, and temperature on WRE were experimentally studied. The results implied the fact that temperature plays a substantial role in the demulsification and has a direct correlation with WRE. In addition, while increasing the concentration up to 40 ppm contributed to reaching a higher WRE, it did not have positive effects on efficiency at higher concentrations (overdose) and just led to more demulsifier consumption. The concentration dependence of WRE was also diminished at high temperatures. At higher levels of temperature and concentration, the time required to reach a high WRE was noticeably reduced. In order to generalize the findings of this study, the measured experimental data were employed to design predictive methods for WRE based on two smart soft-computing paradigms, including Multilayer perceptron (MLP) and Gaussian process regression (GPR). Despite the high accuracy of both models, the MLP model presented the best consistencies with experimental data with average absolute relative error and relative root mean squared error of 0.84%, and 0.01%, respectively during the testing (validation) step. Also, a visual description through the contour diagram confirmed the capability of the recently proposed models to describe the physical variations of WRE under various operating conditions. Ultimately, a sensitivity analysis based on the MLP model was undertaken to shed light on the order of significance of operational factors in controlling WRE. Overall, the findings of the current research, in turn, have a satisfactory contribution to the efficient design of the water removal process from crude oil based on demulsifiers.

Numerical research on liquid water removal mechanism and the influence of pore structure on water removal rate based on real pore GDL structure during shutdown purge of fuel cell

This paper establishes a two-phase flow model of the real pore structure to explore the liquid water removal process during the shutdown purge. The Monte Carlo algorithm is used to randomly throw circles in the rectangular region to simulate the two-dimensional interface of the real GDL pore structures. The real pore structure with different porosity is established by change the number of random circles to explore the influence of porosity on the liquid water removal process. A solid mechanical model is established to explore the variation of GDL under the effect of assembly force. The equivalent model of the compressed real pore GDL is established to explore the effect of the assembly force on the removal of liquid water during the shutdown purge stage. The results show that the liquid water under the ribs is difficult to remove during the removal of liquid water, affecting the speed of liquid water removal. The reduction of GDL porosity is conducive to the diffusion of air and the displacement of liquid water, thus improving the removal speed of liquid water. The assembly force can reduce the porosity below the rib, and effectively promote the removal speed of liquid water below the rib.

World war munitions as a source of mercury in the southwest Baltic Sea

Mercury (Hg) fulminate was used as a primary fuse in World War (WW) munitions, and may consequently be a Hg source for impacted environments. Mercury is a conspicuous and persistent pollutant, with methylmercury (MeHg) acting as a notorious neurotoxin. Considerable amounts of munitions were intentionally dumped in the North Sea and Baltic Sea following the First and Second WWs. After more than 70 years on the seafloor many munitions have corroded and likely release explosive compounds, including Hg fulminate. The Germany coastal city of Kiel was a manufacturing centre for submarines, and accordingly a prominent target for bombing and post-war disarmament. We collected water and sediment samples around Kiel Bay to assess regional levels and quantify any Hg contamination. The munition dump site Kolberger Heide (KH) and a former anti-aircraft training center Dänisch-Nienhof are situated in Kiel Bay, and were targeted for sampling. Sediment Hg concentrations around KH were notably elevated. Average Hg concentrations in KH sediments were 125 ± 76 ng/g, compared to 14 ± 18 ng/g at background (control) sites. In contrast, dissolved Hg in the water column exhibited no site variations, all ranging between 0.8 and 2.1 pM. Methylmercury in sediments and waters did not have enhanced concentrations amongst sites (<30 pg/g and <50 fM, respectively). Sediment-water exchange experiments showed elevated Hg and MeHg fluxes (i.e. >400 pmol m−2 d−1 MeHg) at one KH location, however remaining cores had low to no Hg and MeHg output (<0–27 pmol m−2 d−1 MeHg). Thus, sediments in Kiel Bay proximate to WW munitions could harbor and form a source of Hg, however water column mixing and removal processes attenuate any discharge from the seafloor to overlying waters.

A Protophilic MOF Enables Ni-Rich Lithium-Battery Stable Cycling in a High Water/Acid Content.

Trace protic impurities, such as water and hydrofluoric acid (HF), can severely degrade the stable and long cycling of lithium batteries. Therefore, the costly water removal process is inevitably needed throughout production of lithium batteries, leaving the paradox that energy-saving lithium-battery technology consumes non-negligible amounts of energy. Herein, a unique ionic metal-organic framework (MOF) is reported that enables highly destructive H2 O/HF-tolerant lithium batteries. The isolated ionic fluorine sites in the MOF exhibit unusual protophilicity and efficiently capture ppm-levels H2 O/HF from the highly polar electrolyte solvents. The resulting MOF-based LiNi0.6 Mn0.2 Co0.2 O2 │Li battery achieves over 300 cycles in the presence of 800ppm H2 O or 1107ppm acidic impurity. This tenfold longer battery lifespan relative to those for batteries with conventional standard separators demonstrates its excellent electrochemical cycling performance. The results reveal that the rational use of unique nanoporous features of MOFs can provide new possibilities for long-standing challenges in the lithium-battery industry.

The effects of flow field design on PEMFC

The flow field design plays a crucial role in the performance of proton exchange membrane fuel cells (PEMFCs). An efficient flow field design enhances electrochemical reactions in catalyst layers and facilitates the water removal process at the cathode. This study evaluates two PEMFC designs, rectangular and semicircle baffle flow fields, using computational fluid dynamics modeling. The models incorporate mass, heat and energy transport, electrode kinetics, and potential fields in PEMFCs. The research analyzes the hydrogen and oxygen mass flow rates and water distributions in PEMFCs at operating voltages of 0.3–1 V to determine the effect of the flow field design on performance. According to the results it is clear that flow field design has an important influence on PEMFC power density and performance. The calculated power density at 0.3 V and at 80°C for semicircle and rectangular baffle flow field PEMFCs respectively are 0.37 and 0.23 W cm−2, which indicates that PEMFC with semicircle baffle flow field has better performance in this study.

Capillary forces exerted by a water bridge on cellulose nanocrystals: the effect of an external electric field.

Capillary forces play an important role during the dewatering and drying of nanocellulosic materials. Traditional moisture removal techniques, such as heating, have been proved to be deterimental to the properties of these materials and hence, there is a need to develop novel dewatering techniques without affecting the desired properties of materials. It is, therefore, important to explore novel methods for dewatering these high-added-value materials without negatively influencing their properties. In this context, we explore the effect of electric field on the capillary forces developed by a liquid-water bridge between two cellulosic surfaces, which may be formed during the water removal process following its displacement from the interfibrillar spaces. All-atom molecular dynamics (MD) simulations have been used to study the influence of an externally applied electric field on the capillary force exerted by a water bridge. Our results suggest that the equilibrium contact angle of water and the capillary force exerted by the water bridge between two nanocellulosic surfaces depend on the magnitude and direction of the externally applied electric fields. Hence, an external electric field can be applied to manipulate the capillary forces between two particles. The close agreement between the capillary forces measured through MD simulations and those calculated through classical equations indicates that, within the range of the electric field applied in this study, Young-Laplace equations can be safely employed to predict the capillary forces between two particles. The present study provides insights into the use of electric fields for drying of nanocellulosic materials.

Artificial neural network modeling of microwave-assisted heat pump drying process

Recently, microwave-assisted drying is an emerging drying technique that can help to accelerate the water removal process. In this paper, a microwave-assisted experimental drying study of carrot slides is presented. A microwave-assisted heat pump dryer is fabricated where the drying agent temperature, the supplied microwave power, and the circulative fan speed are easy to adjust. A series of 61 drying experiments is conducted with a range of drying temperature from 35 °C to 45 °C, a range of microwave power from 0 to 1.25 W/gram, and air velocity varied from 0.55 m/s to 1.70 m/s. The drying kinetics of the dehydration process is analyzed. Based on the obtained result, suitable intensive drying conditions for carrot slices are proposed. To extend the applicability of the experimental study, an artificial neural network (ANN) model of the drying process is developed. Instead of estimating the network for individual drying conditions in previous studies, the network is established for the entire range of drying conditions. The results indicate that the proposed ANN model predicts the microwave-assisted drying process adequately.

Toxic Metals (Al, Cd, and Pb) in Instant Soups: An Assessment of Dietary Intake.

Instant soups and noodles are one of the most widely consumed commercial food products. These products are made from ingredients of animal (chicken, meat) and/or vegetable origin, in addition to various food additives that prolong the shelf life of the product. It should be noted that instant soups are a dehydrated product, whose water-removal process can increase the accumulation of contaminants, such as toxic metals (Al, Cd, or Pb), that are harmful to the health of consumers. The content of toxic metals (Al, Cd, and Pb) in a total of 130 samples of instant soups of different types (poultry, meat, and vegetables) was determined by ICP-OES (inductively coupled plasma-optical emission spectrometry). The Al content (32.28 ± 19.26), the Cd content (0.027 ± 0.016), and the Pb content (0.12 ± 0.13) in the vegetable soups were worth mentioning. Considering an intake of twenty grams (recommended by the manufacturer), the dietary intake of Al (19.56% of the TWI set at 1 mg/kg bw/week), the intake of Cd (6.59% of the TWI set at 2.5 µg/kg bw/week), and the Pb intake (16.18% of the BMDL set for nephrotoxic effects at 0.63 µg/kg bw/week and 6.84% of the BMDL set for cardiovascular effects at 1.50 µg/kg bw/week) in the population aged 3-10 years, instant soups are not recommended for the population aged 3-10 years, while their consumption does not pose a health risk for adults. However, it is necessary to consider the cooking water used in the preparation of these products, as it may increase exposure to these toxic metals, in addition to the rest of the diet.

Effects of Gas Diffusion Layer Substrates on PEFC Water Management: Part II. In Situ Liquid Water Removal via Evaporation

Desaturation of polymer electrolyte fuel cells (PEFCs) is a critical operation step for providing cell cold-start performance by minimizing residual water in the gas diffusion layers (GDLs), flow field (FF) channels, catalyst layers and membrane after cell shutdown. In this work, transient liquid water removal processes in the FF channels and GDLs are visualized and quantified by subsecond in situ X-ray tomographic microscopy (XTM), and correlated to high frequency resistance (HFR) measurements of the cell. Time-resolved desaturation profiles are analyzed for three commercially available GDLs with representative substrate dimensions. The influence of different substrates on the GDL desaturation behavior is investigated with a cluster connectivity analysis and saturation-dependent effective diffusivities are determined by numerical simulations. Characteristic drying phases are identified for the HFR curves and confirmed with XTM imaging results, providing fundamental understanding of the desaturation dynamics in the PEFCs and enabling the optimization of GDL substrates and gas purge protocols accordingly.

Ionic Liquid-Type Additive for Lithium Metal Batteries Operated in LiPF6 Based-Electrolyte Containing 2500 ppm H2O.

The presence of trace amounts of moisture in the electrolyte can cause hydrolysis of LiPF6 and deteriorate the stability of lithium metal batteries. Herein, we propose a multifunctional ionic liquid-type additive constituting a 1-methyl-1-butyl pyrrolidium cation (Py14+) and an acetate anion (CH3COO-) (denoted as IL-AC in this study), which can effectively adsorb the trace moisture and thus prevent the hydrolysis of LiPF6 via intermolecular interactions. The prepared IL-AC can also remove HF to suppress the dissolution of transition metal ions from cathode materials through the reaction CH3COO- + HF → CH3COOH + F-. Compared with the baseline electrolyte, the contents of HF and transition metal ions are significantly lower in the electrolyte with 0.5% IL-AC. Upon the addition of 0.5% IL-AC additive and 2500 ppm H2O, the Li||NCM811 battery shows a capacity of 153.7 mAh g-1 after 300 cycles, while the Li||LNMO battery possesses stable capacity retention of 93.22% after 500 cycles at 1C and a Coulombic efficiency greater than 99%. Thus, this work provides a convenient and effective method to absorb trace amounts of water and remove HF in the electrolyte and provides a new path for the expensive and tedious process of water removal from the electrolyte in industry.

Thermodynamic modeling of hydrogen–water systems with gas impurity at various conditions using cubic and PC-SAFT equations of state

Hydrogen (H2) has emerged as a viable solution for energy storage of renewable sources, supplying off-seasonal demand. Hydrogen contamination due to undesired mixing with other fluids during operations is a significant problem. Water contamination is a regular occurrence; therefore, an accurate prediction of H2-water thermodynamics is crucial for the design of efficient storage and water removal processes. In thermodynamic modeling, the Peng–Robinson (PR) and Soave Redlich–Kwong (SRK) equations of state (EoSs) are widely applied. However, both EoSs fail to predict the vapor-liquid equilibrium (VLE) accurately for H2-blend mixtures with or without fine-tuning binary interaction parameters due to the polarity of the components. This work investigates the accuracy of two advanced EoSs: the Schwartzentruber and Renon modified Redlich–Kwong cubic EoS (SR-RK) and perturbed-chain statistical associating fluid theory (SAFT) in predicting VLE and solubility properties of H2 and water. The SR-RK involves the introduction of polar parameters and a volume translation term. The proposed workflow is based on optimizing the binary interaction coefficients using regression against experimental data that cover a wide range of pressure (0.34 to 101.23 MPa), temperature (273.2 to 588.7 K), and H2 mole fraction (0.0004 to 0.9670) values. A flash liberation model is developed to calculate the H2 solubility and water vaporization at different temperature and pressure conditions. The model captures the influence of H2-gas (CO2) impurity on VLE. The results agreed well with the experimental data, demonstrating the model’s capability of predicting the VLE of hydrogen-water mixtures for a broad range of pressures and temperatures. Optimized coefficients of binary interaction parameters for both EoSs are provided. The sensitivity analysis indicates an increase in H2 solubility with temperature and pressure and a decrease in water vaporization. Moreover, the work demonstrates the capability of SR-RK in modeling the influence of gas impurity (i.e., H2–CO2 mixture) on the H2 solubility and water vaporization, indicating a significant influence over a wide range of H2–CO2 mixtures. Increasing the CO2 ratio from 20% to 80% exhibited almost the opposite behavior of H2 solubility compared to the pure hydrogen feed solubility. Finally, the work emphasizes the critical selection of proper EoSs for calculating thermodynamic properties and the solubility of gaseous H2 and water vaporization for the efficient design of H2 storage and fuel cells.

MOF-based cotton fabrics with switchable superwettability for oil–water separation

• The superhydrophobic cotton fabric could transform into superhydrophilic by wetting with ethanol and could restore after drying. • Whether it is water or oil removal process, the flux and efficiency of the fabric was above 15,300 L·m −2 h −1 and 98.6%. • The superhydrophobic fabric possessed excellent self-cleaning properties. • The fabric wetted with ethanol and water successively had good antifouling properties. • The superhydrophobic fabric had good mechanical durability and chemical stability. Superwettability materials with a single function cannot meet the needs of different oil-bearing wastewater separations. This study proposed a preparation method for the swappable superwettability on cotton fabrics. The superhydrophobic fabric surface that was wetted with ethanol transformed from being superhydrophobic/superoleophilic to being superhydrophilic/underwater superoleophobic, and returned to superhydrophobicity after drying. Regardless of whether it is the oil removal process or the water removal process, the flux of the fabric was above 15,300 L·m −2 h −1 , and the separation efficiency was over 98.6%. Although the continuous separation was conducted 50 times, the flux and separation efficiency did not change significantly. The prepared material could exhibit superhydrophobicity after being immersed in solutions of different pH and actual seawater for some time, even after 50 times of sand impact experiments, indicating excellent mechanical durability and chemical stability. Thus, the preparation strategy of the swappable superwettability materials can develop oil–water separation technology.

Polymer hydrogel for water removal from naphthenic insulating oil and marine diesel

The control of water content in industrial oils and fuels is a key factor to avoid degradation during the storage period and guarantee their expected performance. Thus, our work investigated the application of polymer hydrogel to remove water from naphthenic insulating oil (NIO) and marine diesel oil (MDO). Two acrylamide-based hydrogels were synthesized by free radical polymerization: poly(acrylamide-co-sodium acrylate) and poly(acrylamide-co-acrylonitrile). Prior to batch tests for water removal, the hydrogels were characterized by SEM, pore size distribution, DVS, FTIR, and XDR. An extensive physicochemical characterization of MDO and NIO was performed, including the determination of water solubility curves. A 22 factorial design with duplicates was carried out to examine the effects of the hydrogel mass and hydrogel type on the water content in the oils. Finally, kinetic and thermodynamic studies of the water removal process were carried out. In just 60 min, the hydrogel removed approximately 80% of water from NIO and MDO, considering 1 g of hydrogel and 50 mL of emulsion at 25 °C. The two lowest temperatures studied (25 °C and 35 °C) showed the best hydrogel performance. Tests of hydrogel reuse showed the polymer can be regenerated without losing its water removal capacity.

Optimization of the demulsification of water-in-heavy crude oil emulsions using response surface methodology

The current work investigates the effect of oil to kerosene ratio, space velocity, temperature, demulsifier dosage, and wash water ratio on the performance of demulsification of water-in-heavy crude oil emulsions. For this purpose, an electrostatic desalting pilot plant has been utilized to carry out the experiments. Performance has been evaluated by determining the water removal efficiency (WRE) and the salt removal efficiency (SRE) based on operating parameters. Besides, the central composite design based on the response surface methodology was applied to design the experiments, model and optimize the water and salt removal processes. Moreover, the analysis of variance has been used to evaluate the significance of developed models, as well as operating parameters. It was observed that the proposed models for the WRE and SRE were found to be highly significant and presented the p-values < 0.0001. In addition, R2 and adjusted-R2 values were 94.78 and 92.01% for the WRE model, and 97.90 and 95.80% for the SRE model, which also emphasizes the high accuracy of both models. The obtained results demonstrated that the oil to kerosene ratio had the greatest impact on WRE as well as SRE compared to other studied parameters. The results show that the addition of the optimum value of 25 vol% kerosene to the emulsion could increase the maximum WRE and SRE by about 17.4, and 8.1%, respectively. At the same time, adding this volume of kerosene to the oil, in addition to such an increase in WRE and SRE, simultaneously reduced the optimum required demulsifier dosage and wash water ratio from 48 to 27 ppm and 8.5 to 5.5 vol%, respectively. Furthermore, the added kerosene also could increase oil space velocity from 0.5 to 0.7 1/h. The results of numerical optimization indicate that the optimal conditions to maximize the water and salt removal efficiencies were as follows: 75:25 (v/v), 0.7 1/h, 125 °C, 27 ppm, and 5.5 vol%, for oil to kerosene ratio, space velocity, temperature, demulsifier dosage, and wash water ratio, respectively. The maximum efficiency of water and salt removal from heavy crude oil under optimal values were achieved 92.89 and 98.73%.

Airborne ultrasonic application on hot air-drying of pork liver. Intensification of moisture transport and impact on protein solubility

Nowadays, there is increasing interest in developing strategies for the efficient and sustainable use of animal by-products, such as pork liver. In order to stabilize the product, a prior dehydration stage may be required due to its high perishability. The water removal process of pork liver is energy costly and time consuming, which justifies its intensification using novel technologies. In this sense, the aim of this study was to assess the effect of the airborne application of power ultrasound on the hot air-drying of pork liver. For that purpose, drying experiments were carried out at 30, 40, 50, 60 and 70 °C on pork liver cylinders at 2 m·s−1 with (US) and without ultrasonic application (AIR). The drying process was modeled from the diffusion theory and, in the dried pork liver, the protein solubility was analyzed in order to determine the effect of drying on the protein quality. The ultrasound application increased the drying rate, shortening the drying time by up to 40% at 30 °C. The effect of power ultrasound at high temperatures (60 and 70 °C) was of lesser magnitude. Drying at 70 °C involved a noticeable reduction in the protein solubility for dried liver, while the impact of ultrasound application on the solubility was not significant (p > 0.05).

Amphiphilic polymeric photoinitiator composed of PEG-b-PCL diblock copolymer for three-dimensional printing of hydrogels

Herein, poly(ethylene glycol)-block-poly(ɛ-caprolactone) (PEG114-b-PCLx) copolymer is employed to enhance the water solubility of fashionable photoinitiator, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO). PEG114-b-PCLx copolymers are first polymerized via the conventional ring-opening polymerization. Subsequently, TPO encapsulated nanoparticles (TPO@PEG114-b-PCLx) are prepared through the nanoprecipitation method, followed by a water removal process using lyophilization. By altering the PEG114-b-PCLx molecular weights and TPO: PEG114-b-PCLx ratios, the resulting nanoparticles exhibited hydrodynamic average sizes ranging from 190 to 360 d.nm with the TPO encapsulation efficiency of approximately 21–35%. Afterward, these prepared photoinitiators were formulated with poly(ethylene glycol dimethacrylate) (PEGDMA) and methacrylate-functionalized dextran (Dex-MA) before fabricating the 3D-printed hydrogels through digital light processing (DLP). The compressive moduli of the hydrogels covered from 0.13 to 1.79 MPa, depending on the content of PEGDMA and Dex-MA and the degree of substitution of Dex-MA. The cytotoxicity results of printed specimens revealed that the hydrogels are noncytotoxic to chondrocyte and fibroblast.

A comparative analysis of the characteristics of the water removal processes in preparation for incineration of typical wood waste and forest combustible materials

The article presents the results of the experimental studies of the processes of removing moisture from fairly typical and widespread forest combustible materials, and woodworking waste under conditions of their thermal preparation for combustion. Based on the results of the experiments, the main regularities of the drying processes of woody biomass under conditions of radiation-convective heating have been established. The integral characteristics (characteristic times) of the drying process of forest biomass under typical (for this technology) heating conditions have been determined. The experiments were carried out on equipment that provides a low level of error (less than 3.3%) for determining the main characteristics of the biomass dehydration process. The values of the mass rates of moisture removal (Weva) of four promising (for modern and future power engineering) and fairly common types of biomass have been established in the ambient temperature range from 333 to 393 K, which corresponds to the operating modes of the drying equipment of power plants. According to the results of the experiments, it was shown that at relatively moderate ambient temperatures (333≤ Tg ≤ 353 K), the type of wood has a rather significant effect on the characteristics and conditions of the dehumidification process. At the same time, the process of drying wood chips is much faster compared to other types of biomass. As the ambient temperature rises (at 373≤Tg ≤ 393 K), the influence of the type of biomass decreases. As a result of the experiments, a physical model of the process of removing moisture from the bulk layer of biomass was formulated. According to the results of the experiments, it was found that before burning forest biomass in boilers of thermal power plants, it is most advantageous to carry out drying in conditions of relatively moderate (at 333≤Tg ≤ 353 K) ambient temperatures. The studies carried out provide grounds for justifying the use of forest combustible material as fuel (or one of the components of the fuel mixture) at thermal power plants currently operating on coal.