Research Articles

A novel adsorbent was prepared using sugarcane bagasse modified with graphene oxide. The adsorbent was characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction analyses. The adsorption of basic magenta on bagasse and graphene oxide-modified bagasse was systematically studied. The effects of initial concentration, adsorption time, adsorption temperature, and the amount of the adsorbent on the adsorption capacity were examined. Adsorption isotherms were described using both the Langmuir and Freundlich models. It was found that the Langmuir model fit well with the experimental data. The results revealed that the adsorption percentage of basic magenta increased from 55.4% to 99.5% under optimal adsorption conditions. The maximum absorption capacity was 145 mg/g.

A fluidized bed reactor pyrolysis process with recycled non-condensable gases was designed for a capacity of 5 kg/h based on previous basic studies of key parts. The main components of the pyrolysis process were introduced, and the performance was appraised. Initial experiments were conducted between 450 °C and 550 °C to characterize the bio-oil at different temperatures, using non-condensable gas as fluidizing medium. Simultaneously, the contents and higher heating value of non-condensable gases were determined. The results showed that the excellent efficiency of cooling and of capturing the organic compounds, contributing to a high yield of bio-oil and clean non-condensable gases. At 500 °C, the highest yield of bio-oil reached 55.6 wt%, and the yields of bio-char and gas were 23.4 wt% and 21 wt%, respectively. Non-condensable gas not only carried the organic compounds, but also participated in fast pyrolysis. However, temperature was the major factor affecting the chemical components of bio-oil. The heavy bio-oil mainly included long chain macromolecules and phenols. Higher temperature favored degradation and gas purification.

The aim of this study was to develop an approach for the processing of agricultural and organic wastes to produce alcoholic fuels such as ethanol and butanol. The cellulosic materials wheat straw (WS), rice straw (RS), and corn stover (CS) were pretreated with dilute sulfuric acid (H2SO4) and sodium hydroxide (NaOH) individually, and microalgae (Chlorella vulgaris) was treated with dilute H2SO4 and then fermented. The results indicated that pretreatment in acidic condition was best to produce fermentable sugar. However, the high glucose concentration was achieved in C. vulgaris (32 g/L) and WS (20.6 g/L) among lignocellulosic biomass. The microalga that was grown in the nutrient deficient condition had a carbohydrate content of 51% ± 2.1. After fermentation, high concentration of ethanol 9.5 g/L (yield 93.7%) and butanol contents of 7.4 g/L (yield 91.3%) were recorded in wheat straw, whereas C. vulgaris yielded ethanol and butanol concentrations of 14 g/L and 11.8 g/L respectively. The results may help to increase the production of biofuels and reduce the need for imported fuels.

Chemical changes during the maturation period of bamboo are believed to affect its conductance ability. However, prior studies on the bamboo’s chemical changes were inconclusive in implying that the maturation period affects the rhizome’s conductance ability. The rhizome’s conductivity is crucial to rapidly grow a new bamboo sprout. The aim of this study was to determine the variation of chemical attributes among study sites during the maturation period of bamboo rhizome (Gigantochloa scortechinii), and investigate the possibility of a relationship between the chemical attributes and hydraulic conductance. Destructive sampling was conducted using the selective random sampling method on four consecutive rhizomes. The chemical attributes were determined according to the TAPPI standard methods, except for the holocellulose. The results indicated that the ash content, alcohol-acetone solubility, and holocellulose were significantly different (p < 0.01) among the three study sites. In addition, the results indicated that decreasing ash content with age could not be used as a determinant factor for the decrease in the hydraulic conductance. However, increasing the hot water solubility, alcohol-acetone solubility, lignin, and holocellulose with the rhizome age were suggested to be related to decreasing the rhizome’s hydraulic conductance.

Although thermal modification is primarily used to improve wood durability, it also has a tendency to darken lighter colored hardwoods to make them more valuable. This process might also be useful for darkening softwoods, but it will be important to develop colors that customers prefer. One potential species for this application is Douglas-fir (Pseudotsuga menziesii). Consumer preferences for differing degrees of thermal modification (i.e. darkening) were assessed using a convenience sampling survey at a Home Show in Eugene, Oregon. Respondents provided demographic information then ranked five thermally modified samples with widely differing degrees of darkening based on their most to least preferred colors. The lightest colored sample was most preferred; however, the darkest sample was the second most preferred. There were no preference differences for samples in between the extremes, suggesting that there is some latitude with regard to color that could be used to differentiate modified Douglas-fir from other products.

To improve the appearance of the black locust wood under heat treatment, ammonia (AM), acetic acid (AA), and ammonium acetate (AMA) were adsorbed into the black locust wood flour, with or without aluminum sulfate octadecahydrate (ASO). The color parameters (CIE L*a*b*) of the black locust wood flour treated with different conditions were measured. Diffuse reflectance ultraviolet-visible spectroscopy (DRUV-Vis) and the attenuated total reflection/Fourier transform infrared spectroscopy (ATR-FTIR) were conducted to reveal the changes of the chromophore systems. X-ray photoelectron spectroscopy (XPS) was used to demonstrate the extreme valence of the atomic content and the occurrence of a coordination reaction. The color of the wood flour became reddish after the treatment with AMA+ASO. There was an increase in carbonyl structure and carboxyl structure of the wood flour treated with AMA and ASO.

Wood texture has a beautiful appearance and tactile feeling, making it very appropriate for furniture applications. However, the fabrication of a wood texture on wood-based boards can be inefficient and less green when performed using conventional methods. In this study, a wood-like surface on a wood-based board was designed to imitate a wood texture using 3D printing technology. To obtain a high-quality wood texture template for 3D printing, the sharpness of the wood texture was evaluated by image sharpness models, and the scanned wood texture was optimized by colorimetric parameter and sharpness adjustments. The wood texture coating, which was mainly composed of acrylated oligomers, was UV-inkjet 3D printed on the medium-density fiberboard (MDF) from an obtained template. The properties of the printed wood texture coating on the MDF, including its gloss, wearability, adhesion, and hardness, were measured. The results showed that a wood texture coating with high processability can be feasibly 3D printed on MDF to obtain comparable decoration using commercial products.

The structures, crystallinities, Miller indices, and particle sizes of cassava treated with microwave radiation or saline water were analysed and compared. Cassava was milled to sizes of 100 to 120 mesh and then dried under solar radiation for several days. The first set of substrates was treated by microwave radiation at 300 W for 10, 20, or 30 min or at 1000 W for 8 min. The second set of substrates was immersed in saline water for 5 days at salt concentrations of 3.43% or 10% (w/w). The treated substrates were characterised by x-ray diffraction, Fourier transform infra-red spectroscopy, and scanning electron microscopy, and the results were compared with the characteristics of the native substrate. There were significant differences in the characteristics of the microwave- and saline water-treated cassava. Crystallinities of the microwave-treated substrates were lower than those of the saline water-treated samples. A large shift (change in 2θ) in the diffraction peaks was observed for the treated substrates as compared with the native substrate. Examination of the surface morphology suggested that saline water enabled the dissolution and elimination of the undesirable fibres in the substrate; this was not observed for the microwave-treated substrate.

The chemical compositions were investigated for pine essential oils obtained through a solvent-free microwave assistance extraction system (ME) and a conventional hydrodistillation system (HD). The essential oils of P. pinea, P. nigra, P. brutia, and P. sylvestris sawdust were analyzed by gas chromatography and mass spectroscopy (GC-MS). The main components of the pine essential oils were D-limonene (52.8% for ME and 76.6% for HD), β-caryophyllene (12.4% for ME), β-myrcene (2.89% for ME and 1.48% for HD), sesquiterpene hydrocarbons (25% for ME and 9.79% for HD), and total sesquiterpene (25.25% for ME and 9.79% for HD) for P. pinea; D-limonene (28.1% for ME and 79.2% for HD) for P. nigra; α-pinene (76.6% for ME and 77.3% for HD), diterpene hydrocarbons (94.17% for ME and 95.62% for HD), and total diterpenes (94.94% for ME and 96.3% for HD) for P. brutia; β-pinene (36.7% for ME and 42.4% for HD), terpineol, (13.8% for ME and 6.06% for HD) diterpene alcohol (26% for ME and 12.57% for HD), and total oxygenated terpenes (26% for ME and 12.57% for HD)for P. sylvestris. Moreover, the ME was able to produce more diterpene alcohols and sesquiterpene hydrocarbons while the HD showed higher potential for the diterpene hydrocarbons. According to the heat-map correlation, P. pinea showed high similarity with P. nigra, while P. sylvestris was related to P. brutia.

The properties of laminated wood prepared from sengon wood (Falcataria moluccana Miq. Barneby & Grimes) bonded with a modified gutta-percha (MGP) adhesive at various laminae surface roughness profiles were investigated. The wood laminae were sanded using sand papers of KAG grit designation of 80, 100, 150, 220, 300, and 400. A lower value of KAG grit designation with a lager particle size of sand resulted in a rougher surface of the bonded laminae; a rougher laminae surface profile resulted in a greater shear strength of the laminated wood. The shear strength was highest for laminated wood treated with sand paper of KAG 80 and smallest for laminated wood treated with KAG 400. In general, the bonding strength was enhanced with decreasing KAG grit designation. The adhesion performance, in terms of spread and adhesive penetration, improved after sanding, which widened the contact area on the wood surface.