Equilibrium Moisture Research Articles

Influence of glazing type on the drying kinetics and thermal performance of indirect solar dryer for jelly candy

This research aims to evaluate drying kinetics and thermal performance, influenced by the type of glazing. A novel solar dryer that has a phase-change-materials (PCM), heat-recovery (HR), V-groove absorber, and photovoltaic (PV). The research was carried out on jelly candy objects treated with the influence of glazing (single-double-vacuum glazing). Jelly candy has an equilibrium moisture content using single, double, and vacuum glazing collectors, namely 11.59 % (wb), 9.94 % (wb), and 8.83 % (wb), respectively. Then, all types of glazing have an average drying rate value of 0.05 % (wb)/min for three working days. Based on the model accuracy test indicate that the Page and Verma et al. model are the best models for predicting drying kinetics in jelly candy. Specific heat (Cp) and thermal conductivity (k) decreased as the equilibrium moisture content decreased with a range of >1000–2250 J/kg°C and >0.05–0.11 W/m.K, respectively. The heat-utilization-factor (HUF) and coefficient-of-energy (COE) values show an average value of 0.79 and 0.21. Various glazing shows an average heat-gain-percentage (HGP) of 24.82 %. Drying efficiency of indirect solar dryers with single, double, and vacuum solar collectors, namely 83.6 %, 85.2 %, and 85.2 %, respectively. SEM-EDS analysis shows that the surface of the jelly candy is filled with sugar crystals and contains several elements (C,O,K,Fe).

Structure and Digestibility of Spray‐Dried Corn Starch: Influence of Post‐Treatments

AbstractResistant starch (RS) has being attracted attention due to its health benefits. In this study, combination of spray drying and post‐treatments is adopted to prepare post‐treated spray‐dried corn starch (PSDCS) with high content of RS. Effect of post‐treatment conditions on structural and digestive properties of the PSDCS is investigated. Relative humidity can alter the ordered structures of the PSDCSs due to changes in equilibrium moisture content. When fixing relative humidity at 33%, improvements in short‐range structure and long‐range crystalline structure of the PSDCS obtained at alternant temperature of 4/30 °C (12 h/12 h) are better than those of the PSDCSs obtained at other temperatures. The highest content of RS (29.97%) is found in the PSDCS obtained at 4/30 °C, which is approximately 3.3 times of native corn starch and 5.6 times of spray‐dried corn starch. These findings demonstrate feasibility of preparation of starch products with lower digestibility using spray drying combined with post‐treatments and lay the groundwork for the production and application of products with high content of RS.

The Application of Osmodehydrated Tomato and Spinach in Ready-to-Eat Mixed Salad Products: Design, Development, and Shelf Life Study

Osmotically dehydrated cherry tomatoes and spinach leaves were incorporated into Greek salad-type (including OD-treated and air-dried feta cheese trimmings and air-dried olive rings) and green salad-type (including OD-treated and air-dried feta cheese trimmings and roasted ground peanuts) ready-to-eat (RTE) product prototypes, respectively. The osmotic dehydration of cherry tomatoes and spinach leaves was conducted in a pilot scale setting (100 L) in a 60% glycerol-based solution at 35 °C and 25 °C for 180 min and 60 min, respectively. To quantify the moisture transfer between the three ingredients of different moisture content (and water activity), the moisture equilibrium curves for each ingredient of the RTE product were determined. The equilibrium water activity of RTE products was 0.86 and 0.76, respectively. The quality of the RTE products (more specifically, tomato and spinach color and texture, instrumentally measured and sensorially perceived, sensory characteristics) was evaluated. The shelf life of the prototypes (from 4 °C to 20 °C) was kinetically modeled based on sensory deterioration and microbial growth, using the zero-order kinetic model and the Gompertz model, respectively. In the case of the tomato-based product, a shelf life of 54 days (based on sensory deterioration) was achieved at 4 °C, a shelf-life extension of 40 days compared to untreated, fresh-cut tomato. The shelf life of the spinach-based product (based on sensory deterioration) was 36 days at 4 °C, 30 days longer when compared to untreated spinach. Our results indicate that osmotic dehydration was successful in significantly extending the shelf life of such products, contributing to the increased temperature resilience of their keeping quality and allowing for their distribution and storage in a variable cold chain.

Equilibrium Moisture Mediated Esterification Reaction to Achieve Over 100% Lignocellulosic Nanofibrils Yield.

Lignocellulosic nanofibrils (LCNFs) isolation is recognized as an efficient strategy for maximizing biomass utilization. Nevertheless, achieving a 100% yield presents a formidable challenge. Here, an esterification strategy mediated by the equilibrium moisture in biomass is proposed for LCNFs preparation without the use of catalysts, resulting in a yield exceeding 100%. Different from anhydrous chemical thermomechanical pulp (CTMP0%), the presence of moisture (moisture content of 7wt%, denoted as CTMP7%) introduces a notably distinct process for the pretreatment of CTMP, comprising the initial disintegration and the post-esterification steps. The maleic acid, generated through maleic anhydride (MA) hydrolysis, degrades the recalcitrant lignin-carbohydrate complex (LCC) structures, resulting in esterified CTMP7% (E-CTMP7%). The highly grafted esters compensate for the mass loss resulting from the partial removal of hydrolyzed lignin and hemicellulose, ensuring a high yield. Following microfluidization, favorable LCNF7% with a high yield (114.4 ± 3.0%) and a high charge content (1.74 ± 0.09mmolg-1) can be easily produced, surpassing most previous records for LCNFs. Additionally, LCNF7% presented highly processability for filaments, films, and 3D honeycomb structures preparation. These findings provide valuable insights and guidance for achieving a high yield in the isolation of LCNFs from biomass through the mediation of equilibrium moisture.

The Hygroscopic Properties and Sorption Isosteric Heat of Coix Seeds

Coix seeds are one of the most difficult-to-store cereal foods, and in order to maintain their quality during storage, the present study was conducted to determine the moisture adsorption and desorption isotherms of five varieties of coix seeds in the ranges of 10-35 °C and 11.3%-96.0% equilibrium relative humidity (ERH) using a static gravimetric method. The isotherms showed sigmoidal curves, and there was a hysteresis between adsorption and desorption isotherms. Six equilibrium moisture equations were used to fit the isotherms, and the Modified Chung-Pfost (MCPE), Modified Guggenheim-Anderson-deBoer (MGAB), Modified Henderson (MHE), Modified Oswin (MOE) and our developed modified Caurie (MCaurie) equations were suitable for fitting the data, among which MCPE was the best fitting equation. The monolayer water content decreased with increasing temperature, and the content of monolayer water, the density and layer number of adsorbed water, and the content of bound water for desorption were significantly higher than those of adsorption. The absolutely (ERH 65%) and relatively (ERH 70%) safe moisture contents (MC, wet basis, w.b.) of coix seeds were respectively 12.45%-12.82% and 13.15%-13.69% at 25 ℃. At equilibrium moisture content (EMC) less than 14.9% w.b., the desorption isosteric heats of coix seed were greater than the adsorption isosteric heats, and both decreased sharply in a hyperbolic form, approaching the latent heat of pure water at 14.9% w.b. The sorption isosteric heat of large-grain coix seed was slightly less than that of small-grain seed due to more cracks in the kernel back surface and more micropores in starch granular surface and resultantly more moisture sorption capacity. These results suggest that the desorptive and adsorptive behaviors of coix seeds should be differentiated for cooldown aeration, demoisturizing and remoisturizing operation, and the average isotherm can be used for common storage management.

The Effect of Type of Reinforcement, Type of Glue and Reinforcement Place on Mechanical and Physical Properties of LVL

This study investigated the effect of the reinforcement type, glue type, and reinforcement placement on the mechanical and physical properties of LVL. In the study, the glues used were phenol- formaldehyde (FF), epoxy (EX), and polyurethane (PU), while reinforcement materials used were glass fiber, basalt, jute, and cotton fabric. The following three reinforcement combinations were applied: the first was on the bottom surface, the second was on the first adhesive line at the bottom, and the third was on both the bottom and the first adhesive line at the bottom. As part of the study, researchers manufactured 9-layer laminated veneer lumber (LVL) using alder veneers for the surface, and poplar veneers for the middle layers. They produced a total of 39 different combinations of LVL. The mechanical and physical properties of the produced samples were determined. According to the test results, bending strength (BS), modulus of elasticity (MOE), oven-dry specific gravity, and equilibrium moisture content of samples were higher with FF than with other glues. While the samples with EX glue provided the lowest values in water absorption and thickness swelling tests, glass fiber-reinforced samples provided the highest mechanical values. In addition, the samples having reinforcement on the bottom surface provided higher BS and MOE values.

Design, Fabrication, and Performance Evaluation of a Varying Temperature Dehydrator for Food Preservation

This study focuses on creating and evaluating a dehydrator that can operate at different temperatures for preserving food. The dehydrator includes a drying chamber, an axial fan, a heating element, trays, vents, and a thermostat. Various experiments were carried out on the food dehydrator for performance evaluation. The first experiment was carried out on plantain, and it was observed that the drying time decreased as the drying temperature increased. The shortest drying time for plantain drying was obtained at 75℃, which is 210 minutes, followed by 70℃, with a total drying time of 240 minutes, and 65℃, with a total drying time of 270 minutes. Equilibrium moisture content was reached when no more change in weight was observed. These results explained that temperature significantly affected the selected product during dehydration. For the second experiment, it was observed that the higher the proximity of trays to the heating element, the faster the drying time. The shortest drying time for tomato was obtained at the tray closest to the heat source, with a total drying time of 90 minutes. The second tray in the middle had a total drying time of 120 minutes, whereas the third tray at the top took 150 minutes for the tomatoes to completely dry. This boldly explains that the dehydrator’s efficiency depends on the tray position. The food dehydrator increases its utility for drying a wide range of foodstuffs, including fruits, vegetables, meats, and fish, which have different moisture content and drying requirements.

Moisture effect on tensile and low‐velocity impact tests of flax fabric‐reinforced PLA biocomposite

AbstractThis study investigates the hygrothermal aging effect on the tensile and impact behavior of flax/PLA biocomposites. Specimens underwent up to four weeks of conditioning at 40°C in a climate chamber with water. Analysis covered porosity, moisture diffusibility, and transversal microstructure, enabling assessment of tensile strength, tensile modulus, and impact performance in relation to moisture uptake and fiber orientation. The study of tensile properties revealed that at approximately 12% moisture content, stiffness and yield stress decrease, while strength remains constant. Moisture diffusivity is higher in warp and weft yarn directions than the out‐of‐plane direction. Tensile testing at environmental equilibrium moisture reveals greater stiffness in the weft direction, correlated with lower crimp percentage and yarn angle. The main contribution of the paper is the study of the influence of moisture on the impact behavior, the results show that energy absorption capability of flax/PLA biocomposite increases with moisture content.Highlights Fully biodegradable composite material by heat‐compression molding subjected to hygrothermal aging conditions for up to four weeks. The moisture diffusivity in both the warp and weft yarn directions registered higher values in comparison to the out‐of‐plane direction. Tensile testing at environmental equilibrium moisture revealed that the stiffness in the weft direction presented higher values. At 12% of moisture uptake, the stiffness and yield stress reached their lowest values, while strength remained constant. However, the low‐velocity impact properties of the composites exhibited improvement with moisture.

Influence of polyethylene glycol and various carboxylic acids on the physical and mechanical properties of beech wood (Fagus sylvatica) and Scots pine wood (Pinus sylvestris)

ABSTRACT The goal of this study was to investigate the influence on physical and mechanical properties of beech wood (Fagus sylvatica) and Scots pine wood (Pinus sylvestris) modified with polyethylene glycol (PEG) 400 as an alcohol and various carboxylic acids (citric acid, malic acid and 1,2,3,4-butanetetracarboxylic acid). PEG 400, chosen for its large and flexible structure, was expected to minimize the negative effects on mechanical properties. However, contrary to expectations, tensile and impact bending strength decreased – similar to other modifications. Tensile strength decreased (beech: 36.0% to 46.3%), while the modulus of rupture did not show a strong decrease (beech: 2.4% to 15.2%). The modulus of elasticity (beech: 1.6% to 14.7%), compression strength (beech: 11.7% to 40.6%) and hardness (beech: 6.0% to 17.1%) increased. Impact bending strength was reduced (beech: 43.0% to 69.3%). Modifying agents, fixed inside the wood, demonstrated high anti-swelling efficiency during leaching cycles (beech: 27.1% to 45.9%). Equilibrium moisture content was reduced between 20.8% and 39.1% for beech at a relative humidity of 65%.

Prediction Distribution Model of Moisture Content in Laminated Wood Components.

Shrinkage cracks are some of the most common defects in timber structures obtained from woods with an uneven distribution of moisture content and are subject to external dynamic environmental changes. To accurately predict the changes in the moisture content of wood components at any time and position, this study first applied the principles of food drying and established a moisture field model for laminated wood based on the analogy between heat and humidity transfer. A model for predicting the moisture content of wood that considers time and spatial distribution was then proposed. Second, by collecting relevant experimental data and establishing a finite element analysis model, three moisture absorption conditions (0-9.95%, 0-13.65%, and 0-17.91%) and four desorption conditions (34-5.5%, 28-8.3%, 31-11.8%, and 25.5-15.9%) were analyzed. In the moisture absorption comparison, the time needed to reach 95% equilibrium moisture content was 2.43 days, 4.07 days, and 6.32 days. The rate at which the internal components reached equilibrium moisture content exceeded 10 days. The temporal and spatial distribution of wood moisture content revealed the correctness of the proposed wood moisture field model. Finally, the moisture content prediction model was applied in the order of characteristic equation solutions, moisture content gradient difference, and laminated wood size. The results revealed that the established humidity field model can predict the wood moisture content and how it changes over time and in space. Notably, 1-2 orders for the solution of the characteristic equation are recommended when applying the prediction model. The greater the difference in moisture content, the faster the equilibrium moisture content is reached. The moisture content varies greatly based on the component size and position. Notably, the influence of moisture gradient and wood size on the average wood moisture content cannot be ignored.

Impact of sugar reduction on the glass transition temperature and sorption isotherm of freeze-dried tomato powder

The objective of this work was to improve the drying of tomato juices after identifying the main parameters that are responsible for sticking during drying. Glass transition temperature (Tg) which is one of the key parameter, depends on the juice composition, mainly sugar. In order to reduce sugar, centrifugation was applied to the juices. Tg was determined by differential scanning calorimetry (DSC) for freeze-dried tomato juice and tomato pellet conditioned at various water activity (aw) (0.1–0.5). The glass transition curve showed that Tg decreased with increasing of the moisture. Comparison of powders obtained by juice and pellet from centrifugation shows that the Tg of freeze-dried pellets is higher than that of juice at equal aw values. Adsorption isotherms of freeze-dried tomato juice and pellet were determined at 25 °C and a relative humidity (RH) of 0–98% using a dynamic technique. The data obtained were fitted to GAB model that best fitted the experimental data. The equilibrium moisture content (X) value of the freeze-dried pellets are lower and had the same value of 8% dry mass. X is lower because the pellet powders are less hygroscopic than tomato juice powders because of the reduction of soluble compounds by centrifugation, notably sugars. Reducing the product sugar content by centrifugation enables to raise Tg without using carriers and obtain less hygroscopic powders, which is advantageous for product storage.

The hygroscopic behavior of surface compressed wood in response to superheated steam treatment at varying steam pressures

Superheated steam treatment has been shown to be an efficient strategy for enhancing the dimensional stability of compressed wood. This study evaluated the hygroscopic behavior of surface compressed (SC) wood subjected to superheated steam treatment (SHTSC wood) at varying steam pressures (0.1 MPa, 0.3 MPa, 0.5 MPa, and 0.7 MPa). As the steam pressure increased, the equilibrium moisture content (EMC) of SHTSC wood showed a gradual decrease throughout the hygroscopic range, indicating improved hygroscopic stability. The reduction in EMC for SC wood was associated with a decrease in polylayer moisture content (Ms) from 0% to 95% RH, while the EMC reduction for SHTSC wood was attributed to the combined effect of diminished monolayer (Mh) and Ms. The superheated steam treatment resulted in a range of chemical alterations in the SHTSC wood, including a decrease in hemicelluloses content and the quantity of sorption sites (–OH, C–O groups). Concurrently, there was a relative augmentation in the content of cellulose and extractives, alongside a heightened degree of lignin cross-linking. Furthermore, the superheated steam treatment also affected the cellular structure of the SHTSC wood, resulting in an increased ratio of macropores to mesopores, as well as the formation of microcracks within the cell wall. These changes became more pronounced as the steam pressure elevated, contributing to the reduced hygroscopic characteristics and improved dimensional stability of SHTSC wood.

Remotely controlled smart monitoring system of hermetic paddy storage to reduce postharvest losses in Bangladesh

In Bangladesh, where agriculture forms the backbone of the economy, efficient grain storage is crucial, particularly for paddy storage. Traditional methods like gunny bags and plastic containers are common, but the recent introduction of hermetic storage technologies, such as GrainPro bags and hermetic cocoons, have significantly reduced postharvest losses paddy. However, most research focuses on oxygen (O2) and carbon dioxide (CO2) levels in those open storage systems. This study introduces an innovative, cost-effective remote monitoring system for hermetically sealed grain storage, designed using locally sourced components, including a Digital Hygrometer, WiFi Mini IP Camera, and a Remote Controller unit. Tested over a 125-day period at Advanced Storage Lab, Bangladesh Agricultural University, the system effectively monitored the internal environment of the storage units. Key findings show that the internal temperature of the storage bags varied between 16.7°C and 29.2°C, demonstrating lesser fluctuation compared to the ambient temperature range of 16.1°C to 33.5°C. The relative humidity inside the storage units remained stable between 45 % and 54 %, in contrast to the external humidity range of 45 % to 81.2 %. Additionally, using the Steffe and Singh equation, an increase of 0.512 % in Equilibrium Moisture Content (EMC) of paddy was recorded. Notably, there was no evidence of insect or mold growth after 125 days of storage. This study's remote monitoring system not only marks a significant advancement in hermetic grain storage technology but also contributes to sustainable agricultural practices. It provides a practical, real-time solution to monitor and manage key environmental parameters, ensuring the preservation of grain quality over time.

Moisture Transfer Characteristics and Microbiological Stability of Fermented Pre-gelatinized Plantain and Soybean Based Complementary Food Flours

The effect of gelatinization and fermentation on the moisture sorption characteristics and microbial stability of complementary foods from unripe plantain fruits and soybean seeds was evaluated. The plantain was heated to obtain 10%, 18%, 23%, 33%, 74% and 100% starch gelatinization. The samples were fermented, dried and ground to flour. Plantain and soybean flour were mixed by material balance to produce 16% protein complementary foods. Moisture sorption isotherms wereinvestigated at 10, 20, 30, and 40 ° C using the gravimetric method. The BET equation was fitted to the experimental sorption data, and the Clausius-Clapeyron equation was used to determine the isosteric heat of sorption. The microbial stability of the gruels was evaluated using the microbial challenge test with Staphylococcus aureus. With better results from fully gelatinized samples, gelatinization and fermentation reduced the hygroscopic properties of the dehydrated products, with the gelatinized fermented samples having the least equilibrium moisture contents, monolayer moisture values, surface area of sorbent, and net isosteric heats of sorption, an indication that these samples could be stored at temperatures as high as 40 ° C with extended shelf life. The microbiological stability of foods was enhanced by fermentation, since microbial growth was suppressed in fermented samples, offering perspectives for microbial stability of the products.

Characterization of multilayer bacterial cellulose-chitosan films loaded with grape bagasse antioxidant extract: Insights into spectral and water properties, microstructure, and antioxidant activity

This work explores the development and characterization of composite multilayer films comprising bacterial cellulose (BC) and chitosan enriched with antioxidant compounds from grape bagasse extract (GE) and glycerol. SEM images revealed a compact structure with successful interactions between BC and chitosan, confirmed by FT-IR analysis. Equilibrium moisture content, water vapor permeability (WVP), swollen capacity, and solubility were systematically investigated, unveiling the influence of glycerol and GE concentrations. Moisture content increased with elevated glycerol and GE levels, attributed to their hydrophilic nature. WVP rose with higher concentrations of hydrophilic compounds, affecting the films' permeability. Swollen capacity decreased, and solubility increased with the addition of GE and glycerol, indicating a more compact film structure. The incorporation of GE conferred antioxidant properties to the films, as evidenced by DPPH and ABTS+ assays, and Total Phenolic Content (TPC) determination. TPC values varied from 0 to 1.75 mg GAE/g dried film, depending on GE. Fourier Transform Infrared Spectroscopy (FT-IR) highlighted polymeric associations, and UV–Vis spectra demonstrated enhanced UV-blocking properties. Overall, these multilayer films offer promising applications in food packaging, leveraging natural antioxidant sources for an enhanced functionality.

Desorption properties of taioba (Xanthosoma taioba E.G. Gonç.) leaves: A non-conventional edible plant

This study aimed to determine the desorption isotherms and the thermodynamic properties of taioba leaves. For this, gravimetric-static method was used to determine the equilibrium moisture content (EMC) and water activity of taioba leaves at nine storage and drying temperatures (5–80 °C). The proximate composition was also determined. The Clausius-Clapeyron and Gibb's-Helmholtz equations were used to determine the net isosteric heat of desorption and differential entropy, respectively. The enthalpy-entropy compensation theory was also investigated. The relationship between water activity and equilibrium moisture content was best described by GAB model (Radj2 ≥0.987; χ2.105≤3.126; RMSE≤0.006) for the whole range of relative moistures and temperatures. The sigmoid-shaped type II was predominant at all temperatures. The net isosteric heat of desorption decreased from 8907.62 to 1120.15 J/mol as the moisture content increased. The linear relationship between enthalpy and entropy endorsed the enthalpy-entropy compensation mechanism in which TB > Thm, thus, an enthalpy-driven process. The free Gibbs energy was less than zero spontaneous (ΔGBstorage = −728.79 J/mol and ΔGBdrying = −1217.20 J/mol), indicating that water desorption is spontaneous. The spreading pressure varied from 0.001 to 0.05 J/m2 for all temperatures studied. The water surface area tended to decrease with increasing temperature, ranging from 185.71 to 251.97 m2/g. Therefore, this study provided an understanding of the water desorption properties of taioba leaves, contributing to the development of storage and drying practices.

Using industrial waste in porous building materials for indoor humidity control

This study uses waste bricks and waste catalyst as raw materials in the synthesis of humidity control building materials with high structural strength. This paper explores the feasibility of producing porous humidity control materials (PHCM) through the billet sintering of waste brick with various quantities of waste catalyst (0 %–40 %) for indoor construction. N2 adsorption and desorption isotherms revealed that PHCM exhibits Type-IV adsorption with H3 hysteresis loops, indicating a network of interconnected mesopores with diameters ranging from 3 to 17 nm. Humidity control analysis revealed that increasing the waste catalyst content significantly enhanced the equilibrium moisture content and moisture adsorption and desorption capacity. This study determined that the adsorption of moisture within the PHCM relies on capillary condensation within the mesopores. Under 95 % relative humidity (RH), the highest equilibrium moisture content (2.97 kg/kg) and 12-h moisture adsorption capacity (72.41 g/m2) were obtained in specimens prepared at a sintering temperature of 1000 °C with a 40 % spent catalyst. This excellent adsorption capacity can be attributed to the high surface area of the waste catalyst, which increased the surface area of PHCM from 0.013 to 8.529 m2/g. This study demonstrates the benefits of synthesizing PHCM using waste bricks and catalysts in terms of porous properties, mechanical properties, and humidity control performance.

Measurement and modeling of moisture equilibrium and methane adsorption in shales from the southern Sichuan Basin

The adsorption characteristic of methane in water-bearing shale is essential for the accurate estimation of shale gas reserves. The sorption mechanisms of moisture and methane in shale remain poorly understood. In this work, moisture equilibrium measurements in shales were conducted to study moisture absorption characteristics. The governing factors for moisture absorption were determined, and the suitability of moisture absorption models was evaluated. An innovative water saturation apparatus and an improved methane adsorption system were built to measure methane adsorption in high water-bearing shales. The suitability of the Langmuir model in describing methane adsorption in water-bearing shale was studied. A predictive model for methane adsorption in water-bearing shale was developed based on improved BP neural network algorithm, which was further utilized to determine the primary governing factors for methane adsorption. The results revealed that the equilibrated moisture content in shale presents a three-stage and S-type ascending trend with increasing relative humidity. The methane adsorption amount shows a slide-type downward trend with the increase of water content. The Peleg model demonstrates the superior performance in describing the hygroscopic isotherms, and the Langmuir model performs poorly in characterizing methane adsorption in shales with high water contents. The controlling factors for the ultimate moisture content mainly include specific surface area, average pore diameter, carbonate and pyrite content. The methane adsorption in water-bearing shale is mainly governed by water content and specific surface area. The results of this work enrich the understanding of the adsorption mechanisms of shale gas and provide a solid basis for the assessment of shale gas reserves.

Water uptake and permeability in sapwood and heartwood of hydro-thermally proceed Turkey oak

ABSTRACT This study aimed to investigate the combined effect of steaming and heating on the equilibrium moisture content (EMC) of Turkey oak (Quercus cerris L.) wood over a nine-year period. The study also aimed to determine the impact of steaming on water absorption and water permeability, crucial for the durability of the species against environmental factors. The specimens underwent thermal modification with and without steaming, then were stored under laboratory conditions for ten years. The mass of the specimens was monitored throughout the ten-year period. To measure the water uptake capacity, the specimens were soaked in water for 120 hours. The water permeability of the specimens was assessed using a pressurised chamber. The results showed that the moisture content of thermally-modified oak was constant under laboratory conditions after nine years, further improved by steam treatment. The research also revealed that the steamed wood absorbed more water during water submersion compared to the unmodified wood. When the steaming treatment was applied, there was a significant increase in permeability in the sapwood compared to the heartwood, due to anatomical variations. Despite this, statistical noise, and material variability, alongside tylosis presence, underline the need for examining more specimens in future studies.

Hydrophobicity and performance analysis of beverage and agricultural waste torrefaction for high-grade bio-circular solid fuel

Torrefaction is recognized as a high-performance technology for converting raw biomass into high-grade solid biofuel. In this study, hydrophobic and ANOVA analyses were employed to investigate torrefied brewery waste, palm kernel shell, and water hyacinth residue. Herein, the torrefaction experiments were conducted at four temperatures (180, 230, 280, and 330 °C) for a residence time of 30 min. The biomass type and temperature were crucial in determining the optimum conditions for three response parameters: energy yield (EY), specific energy consumption (SEC), and hygroscopic reduction equilibrium (HRE). Hydrophobicity was assessed by measuring the contact angle (CA), and equilibrium moisture content (EMC) to represent hygroscopic behavior. The ANOVA results indicated that temperature had the most significant impact on the response parameters. Optimal torrefaction of brewery waste at 180 °C yielded an EY of 82.05 %, SEC of 81.88 kWh/kg, and HRE of 23.2 %. These findings highlight the advantages of biomass-derived torrefaction products in waste utilization, transport, and storage of biomass-derived torrefaction products. Furthermore, this study demonstrates an efficient method for enhancing the fuel quality of biomass, contributing significantly to the bio-circular green economy concept.