Volume 18 Issue 3

The stable silica sieve-based HBeta-SBA-15 catalyst-carrier was successfully prepared by a hydrothermal synthesis method, and then Ni₂P/HBeta-SBA-15 new hydrodeoxygenation catalyst was successfully loaded by the equal volume impregnation method. It was characterized by X-ray diffraction (XRD), N₂ adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and pyrolysis-infrared (Py-IR) methods. The results showed that SBA-15 was successfully immobilized on HBeta to form a microporous and mesoporous composite carrier. The introduction of SBA-15 not only increased the specific surface area of HBeta-SBA-15, but also reduced its acidity. After loading the active metal component Ni₂P, the structure of the catalyst has not changed much. Hydrodeoxygenation (HDO) of phenol model compounds over Ni₂P/HBeta-SBA-15 catalyst was studied in water. The response surface analysis showed that the conversion of phenol was 84.4% and the selectivity of cyclohexane was 94.2% at a lower temperature of 240 °C. The effect of reaction conditions on the yield of cyclohexane was as follows: the reaction temperature > the amount of hydrogen > the amount of catalyst > the reaction time. This study provides theoretical guidance for upgrading biomass pyrolysis oil to green fuel through hydrodeoxygenation.

Recently, new brake pads have been developed using sustainable materials that are not harmful to the environment. In this study, the effect of using blue-colored Cupressus arizonica cones was determined as a friction modifier in brake pad composites. Four different samples were prepared by grinding the cone material. The samples’ physical and chemical properties and performances were compared, and finally, their microscopic analyses were visualized by scanning electron microscopy. Maximum friction coefficient and minimum wear rate are required for brake pads. The maximum friction coefficient of 0.39 and the minimum wear rate of the samples containing Cupressus arizonica were obtained in the 0.124X10^-7 cm³/Nm BCA3 sample. When the brake pads developed from lignocellulosic biomass were compared, it was determined that the BCA3 sample met the most reasonable performance values.

Panel furniture uses an intelligent management system, combined with the production method of splitting orders by process, to achieve large quantities and large-scale manufacturing, but because of the insufficient and incomplete use of technology, capacity bottlenecks still exist. The problem of rework and replenishment is a long-term problem in furniture production. Under the constraints of existing production rules, the time difference of plates rework forces the original batch of plates to wait, which reduces the efficiency of warehousing. From the perspective of intelligent manufacturing for the optimization of the plates rework process, this study, through on-site observation records and data analysis of the production system, aimed to find short-term solutions and long-term solutions. In the short-term response, the time node for the completion of the replenishment is mainly according to the process regulations, and the plates are packaged into the warehouse after the replenishment is completed in batches. The long-term response strategy is mainly to achieve the interconnection of different production systems to achieve mutual information, and the paperless online operation of the plates rework process increases the subjective initiative of each process to improve the overall efficiency of the plates rework process.

This research was conducted to determine to the effects of indole-3-butyric acid (IBA) doses and propagation season on rooting rates and some root parameters of Rhododendron species, R. ponticum L., R. luteum Sweet, R. ungernii Trautv, and R. caucasicum Pallas. Air layering technique and IBA doses (0, 500 ppm, and 1,500 ppm) were applied to each Rhododendron species in their natural habitat in autumn and spring. In the present investigation, dry root weight (mg), root length (cm), root volume (cm³), and root diameter (mm) were investigated as root quality parameters. The highest rooting efficiency (100%) was obtained from R. caucasicum and R. ungernii species. The rooting efficiencies of R. ponticum (between 6.67% to 66.67%) and R. luteum (between 0% to 53.33%) species were lower than the other two species. The heaviest dry root (266.10 mg), the largest root volume (1.49 cm³), and the thickest root diameter (0.05 cm) were obtained in autumn and 1,500 ppm IBA dose from R. caucasicum species. The longest roots, 349.21 cm, were formed in the R. ungernii species in the spring, during the air layering, in which 500 ppm IBA dose was applied.

Hydrogen peroxide is an environmentally friendly bleaching chemical that is widely used in alkaline media in the pulp and paper industry. In this study, unconventional reaction conditions of the conventional bleaching P-stage were performed to evaluate its effect on cellulose. The objective was to “tailor” the cellulose degradation according to different applications, such as dissolving pulps. Different operating conditions were studied: pH variation (alkaline or acidic medium), as well as the addition of Cu(II) or the Cu(II)-phenanthroline complex. The hypotheses considered were (1) Using H₂O₂ in unconventional conditions will favor hemicelluloses removal after depolymerization and will lead to the desired cellulose degradation, and (2) H₂O₂ oxidation carried out under unconventional conditions will favor the dissolving ability of cellulose.

Thermal modification mechanisms and their effects on physical and mechanical properties of native Amazon hardwoods are not yet completely understood. It is expected that such treatments can improve the properties of low-value Amazonian woods and sapwood residues. This study aimed to investigate the impact of heat treatment on the swelling and mechanical properties (strength and stiffness to Static Bending and Janka hardness) of tauari wood (Couratari spp.), a low-value Amazonian hardwood. For this, tauari wood samples were thermally modified in an electric oven under hot air irradiation at final temperatures of 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, and 210 °C for 2.5 h. The main results showed that thermal modification increased the hydrophobicity of tauari wood without any noticeable effects on the mechanical behavior of the wood up to 200 °C. It was stated that up to 200 °C thermal modification is beneficial in terms of gains in hydrophobicity. In contrast, above 200 °C, despite an increase in hydrophobicity, consistent decreases in strength (MOR) and hardness were observed.

Effects of temperature dependence and relative humidity were studied relative to the thermal conductivity of heat-treated pine and heat-treated beech, which are frequently used for building construction. Pine and beech wood were exposed to heat treatment at 180, 200, and 220 °C in nitrogen gas for 2 h. As a result, the thermal conductivity values of the heat-treated wood decreased as the temperature of the heat treatment process increased and relative humidity increased. However, thermal conductivity of wood became more stable after heat treatment under relative humidity changes. The thermal conductivity values increased with rising mean plate temperatures, while the temperature dependence of the heat-treated wood was not affected by the relative humidity changes. Consequently, heat-treated wood, with variable humidity without excessive heat changes, can be preferred for the construction of buildings.

Effects of pressure, dewatering time, and sludge cake thickness on the dewatering of wastewater sludge by the hydraulic dehydrator under the condition of adding CaO and FeSO₄ were analyzed using the response surface method (RSM). It was found that when the parameters of pressure, dewatering time, and sludge cake thickness were changed, the trends of dewatering papermaking sludge and municipal sludge were similar under the condition of raw sludge with 3% CaO and 3% FeSO₄. Specifically, the increase of pressure and dewatering time promotes the dewatering effect of wastewater sludge, and the thinner the sludge cake is, the better the dewatering effect. The water content can be affected by the change of pressure, dewatering time, and sludge cake thickness. In response surface analysis, the model F-value and coefficient of determination (R²) were 541.43 and 0.9986, respectively, indicating high significance and good correlation. In the model, the change of pressure, dewatering time, and sludge cake thickness affected the water content of paper sludge. Particularly, the increase of pressure and compression time enhanced the dewatering efficiency. The thinner the sludge cake was, the better the dewatering effect of paper sludge was.

Bambusa arundinacea (Retz.) Willd. is a large and thorny bamboo species used for construction and scaffolding purposes. Bamboo fibers, which are an important part of bamboo, give bamboo its excellent mechanical properties. The goal of this work was to get more information about fiber in order to learn more about bamboo material. It was tested for different ages, heights, and radial positions using the nanoindentation method. The results showed that the mean values of indentation modulus of elasticity and hardness of this species were 20.79 GPa and 497.01 MPa, respectively, and that the mechanical properties of the fiber cell walls were less affected by the three factors and were generally consistent. In regards to the age factor, it had little effect on the indentation modulus of elasticity, while the hardness increased slightly with age. The indentation modulus of elasticity and hardness tended to increase with increasing height. The fiber strength was relatively stable in different parts of the radial direction.

Water contamination has reached crisis proportions due to the rapid development of industrial operations. Humans, animals, and aquatic life are all at risk of accumulating non-biodegradable heavy metals and dyes in the water supply. The adsorption process using activated carbon was identified as the most efficient, economical, and facile method. Activated carbon has gained widespread popularity because of its specialty as an adsorbent in wastewater treatments. In addition, the abundance and inexpensiveness of local bamboo can be explored in producing a cheaper and more sustainable source of commercially activated carbon. Hence, this study aimed to investigate the optimal parameters for effective activated carbon production using G. albociliata, a bamboo species by characterizing its material properties and adsorption ability. Fourier infrared spectra and scanning electron microscopy were employed to identify the functional groups and surface porosity of the activated carbon produced. The adsorption abilities of the heavy metals were determined by atomic adsorption spectroscopy and via the adsorption of dyes by ultraviolet-visible analysis. This study revealed that the bamboo-based activated carbon was a powerful adsorbent and a non-toxic agent for wastewater treatment. The copper, zinc, and methylene blue would be removed effectively by more than 99.2%.