Volume 14 Issue 3

The object of this paper was to obtain stable and reproducible dynamic contact angles (CA) and calculate the surface energy (SE) of bamboo fiber. The average wetted perimeter of bamboo fiber was determined using the Wilhelmy technique. The dispersion and polar components of the bamboo fiber at different immersion velocities were also investigated using the Owens-Wendt approach. The results indicated that the use of the mean wetted perimeter of 30 fibers to estimate the dynamic contact angle was feasible and accurate. As the measured velocity increased, the dynamic advancing contact angle of bamboo fiber first rapidly increased and then gradually stabilized. The surface energy of bamboo fiber presented a tendency of nonlinear decrease when the test speed increased. A measured velocity set from 1 mm/min to 3 mm/min was reasonable for the bamboo fiber dynamic CA test, with an obtained SE of 41.7 mN/m to 43.6 mN/m. A correlation and partial correlation analysis showed that the reliability coefficient had 14.1% correlation between the dynamic CA and measure velocity was induced by the synergistic effect of the testing liquid. The SE of bamboo fiber was negatively correlated to its dynamic advancing CA.

The scarcity of quality feed is a major constraint to livestock productivity, and it is attributed to recalcitrant lignin, which hinders the utilization of crop residues. White-rot lignicolous fungi have been used for enrichment of crop residues through fungal pre-treatment, but dry matter loss is inevitable. Versatile peroxidase oxidizes a diverse class of aromatics without mediators and plays a key role in ligninolysis. In this study, the efficacy of a novel versatile peroxidase isolated from a wild species was evaluated for its effect in the delignification of crop residues. The strain identified as Lentinus squarrosulus (TAMI004, BankIt2098576 MH172167) demonstrated predominant versatile peroxidase activity amongst screened isolates in solid-state and submerged fermentations; it displayed hybrid characteristic of manganese oxidation and manganese independent reactions on aromatic compounds. The manganese oxidizing peroxidase activity was 12 U/mL in submerged and 131 U/mL in solid-state fermentation. Treatment of crop residues with L. squarrosulus extract rich in versatile peroxidase showed a decrease in neutral detergent fiber, acid detergent fiber, and acid detergent lignin contents, prompting delignification. Thus, the use of versatile peroxidase in enhancing the digestibility of straws is substantiated through proximate and in vitro digestibility analysis. Thus, the potential use of versatile peroxidase in increasing the in vitro degradation of straws for enhancing feed utilization in ruminants was substantiated.

To enhance the fire-resistance of bamboo, the bamboo was first exposed to sodium hydroxide solution, and then immersed in a suspension of magnesium aluminum layered double hydroxides (MgAl-LDHs) to fabricate modified bamboo (NLB) with a coating of MgAl-LDHs on the surface. X-ray photoelectron spectroscopy showed that the surface of bamboo was coated by the MgAl-LDHs after modification. Fourier transform infrared spectroscopy analysis demonstrated that more hydroxyl groups were available on the bamboo surface after pretreatment with sodium hydroxide solution. The morphology of the MgAl-LDHs coating was firmer and denser with evidence from scanning electron microscopy and energy dispersive X-ray spectrometry. Leaching resistance was thereby enhanced. In addition, the cone calorimeter results showed that the peak heat release rate of the NLB was 29.1% lower than that of untreated bamboo, the total heat release decreased by 24.4%, the smoke release rate and total smoke release decreased by 40.5% and 47.8%, respectively, and the peak of carbon monoxide production decreased by 26.7%. The maximum average heat dissipation rate decreased by 24.0%, and the shape of residual charcoal of the NLB was more complete than that of untreated bamboo after fire. Therefore, NLB has excellent fire resistant and smoke suppression properties.

Particleboards were made using particles from sugarcane bagasse and eucalyptus residues of the pulp industry. The particleboard properties were evaluated according to ABNT NBR 14810-1 (2013), ABNT NBR 14810-2 (2013), and ANSI A208.1 (1999) standards, which compared the efficiency of castor oil-based polyurethane resin (PU-Castor) and urea-formaldehyde resin (UF). The particleboards were composed of 60% wood particles and 40% bagasse, with a 10% adhesive dose based on the dry mass of particles. The following parameters were evaluated: apparent density, moisture content (MC), thickness swelling after 24 h, modulus of rupture (MOR), modulus of elasticity to static bending (MOE), and internal bond strength of panels (IB). The results obtained demonstrated the potential use of eucalyptus and sugarcane bagasse residues in the production of high-density particleboards. The panels produced with PU-Castor showed greater efficiency, and their physical and mechanical properties were compatible with the requirements of the Brazilian standard for P4 panels (structural panels for use in dry conditions) and the American standard for H-3 panels (high industrial density).

The effects of the TanWood thermal modification process on the resistive properties of Tectona grandis juvenile wood were verified, and the best setting for the use of a resistive moisture meter was determined for both untreated and thermally modified wood (TMW). Sixteen treatments were assessed for both untreated and TMW according to three factors: moisture meter scale (four levels), electrode length (two levels), and grain direction (two levels). Moisture content was measured in four steps with equilibrium moisture contents of 6.0%, 8.6%, 12.2%, and 15.6%. For statistical analysis, the oven-drying moisture content was used as the standard. Statistical analysis included the statistics bias, mean absolute difference, mean square error, tests of linear correlation, and comparison of means. The TanWood process of thermal modification significantly changed the resistive properties of Tectona grandis juvenile wood once different results were found for untreated and TMW regarding the meter’s scale of use and the reliable ranges of moisture content measuring.

The influences of various factors on the tensile strength loading caused by steel bolt-nut connections on Cupressus funebris wood components in directions perpendicular and parallel to the grain were studied. The focus was the interference fit parameter between the nut and the pre-drilling hole, the nut embedded depth, and the embedded nut diameter using the single factor method. The optimum parameters for bolt-nut connections with C. funebris wood components both perpendicular and parallel to the grain component structures were obtained via a single factor experiment and verified by simulation using ANSYS finite element analysis software. The experimental and simulation-based results revealed that the optimum parameters with maximum tensile strength for the bolt-nut connections with C. funebris wood components were an interference fit of -0.80 mm, a nut embedded depth of 25 mm, and an embedded nut diameter of 15.5 mm. Considering the needs of practical applications, the optimum interference fit parameter between the nut and pre-drilling hole was -0.80 mm, increasing the length of the nut within the allowable range of part size was beneficial, and it was not suitable to increase the diameter of the embedded nut to improve the part’s performance.

Sugar palm (Arenga pinnata) is a type of natural fiber that belongs to the Palmae family. It is versatile, readily available, and virtually the entire tree can be formed into many different products. This paper discusses the effect of vacuum resin impregnation on a single sugar palm fiber (SPF) using various thermosetting resins such as epoxy, vinyl ester (VE), and polyester (PE). The fibers were vacuum impregnated at a constant pressure of 600 mmHg for 5 min. The excessive resins were wiped off, and the impregnated fibers were cured in an oven for approximately 30 min at a temperature of 140 °C. Following this, the tensile properties of the single SPF impregnated with epoxy, VE, and PE were determined. The results indicated that impregnation of SPF with epoxy resin increased the tensile strength and modulus of SPF 50% and 59%, respectively. Scanning electron microscope images also illustrated that the epoxy resin offered better impregnation on the SPF compared to the other thermosetting resins. A suitable application for the impregnated SPF is as a roofing material.

Ni-based catalysts supported on olivine were synthesized for cracking the biomass and producing the syngas. Syngas is used directly as fuel source for the cooling, heating, and power (CCHP) system, which can be produced through biomass pyrolysis process. Integrating combined CCHP systems with biomass pyrolysis results in a sustainable distributed energy system that effectively utilizes biomass resources and improves energy efficiency. To achieve a higher energy efficiency and more cost-effective operation, a simplified cost analysis method based on the Advanced System for Process Engineering (Aspen Plus) was applied to the CCHP system based on biomass pyrolysis. First, syngas was used as a fuel source for the CCHP system, which can be produced through a biomass pyrolysis experiment. In the experiment, the yields of the gas before and after the addition of a catalyst were compared. Second, syngas was passed to the reactor in Aspen Plus, which simulated the calorific values of the syngas produced by biomass pyrolysis under different conditions. Moreover, the simulated syngas heat values were applied to a TFRJ3K straw gas engine. Finally, the cost of the syngas for power generation, cooling, and heating was calculated. The power generation cost was 1.2 RMB/kW, the air conditioning refrigeration cost was 22.752 RMB/d, and the household heating cost was 20 RMB/d.

Stratified downdraft gasification using rice husks and wood pellets was carried out under different air mass flow rates using both experimental and numerical methods. The flame propagation rate was calculated from the temperature profile at different time steps and was used as the prerequisite to calculate the equivalent ratio in modeling the combustion zone. Chemical equilibrium modeling was employed to predict the temperature and composition of the sample in the combustion zone. Finite kinetic modeling was used to simulate the reduction zone. The initial temperature and composition of the reduction zone simulation were obtained from the chemical equilibrium results taken from the combustion zone. The flame propagation speed of the rice husk was found to be around five times greater than wood pellet at the same air flow rate. The peak temperature of both fuels had similar values. For all air mass flow rates, the equilibrium modeling over-estimated the peaks in comparison with the experimental tests. The kinetic model was sensitive to the input temperature at the zone inlet. The predicted temperature in the reduction zone demonstrated high kinetic activity at the top of the zone due to a high gas temperature. The predicted temperature was in agreement with the experimental test results.

Spent mushroom substrates, Tremella fuciformis (Tf), Flammulina velutipes (Fv), and Lentinula edodes (Le), were used to produce biochar at different temperatures (300 °C, 400 °C, 500 °C, 600 °C, and 700 °C). Elemental compositions and surface properties of derived biochar were determined. The yield and volatile matter (VM) of the biochars decreased as the pyrolysis temperature increased with Le300 having the highest yield (47.4%). The highest VM was obtained in Tf300 (79.6%). The biochars were alkaline, with Fv700 having the highest pH (11.6). Pyrolysis temperature and feedstock influenced nutrient composition of biochars and highest values were obtained in: Tf300 (N=2.07%), Fv700 (P=12.0 g/kg), Le700 (K=21.9 g/kg), Fv600 (CEC=32.3 cmol/kg), Fv700 (Ash=33.4%) and Le700 (C=58.6%). Heavy metals in the Fv biochar were highest but within their tolerable limits. Fourier transform infrared spectra showed various functional groups on the biochar surfaces with C-O being dominant (except on Le biochar). X-ray diffraction revealed that SiO2 and CaCO3 were present on biochar surfaces. The Fv biochars had the largest surface area with Fv400 having the highest value (210.6 m2g-1) while Le400 had the highest average pore diameter (159.7 Å). These properties render the biochars suitable as soil amendment and in environmental remediation.