Volume 9 Issue 3

In this study, bio-oil was analyzed by gas chromatography mass spectrometry (GC-MS), and the evaporation characteristics of bio-oil were studied at different heating rates (10, 20, and 30 °C/min) from 35 °C to 250 °C by a thermal analyzer (TG-DSC). The TG-DSC results of bio-oil showed that the heat requirement of bio-oil during the evaporation process ranged from 2.072´103 to 2.299´103 J/g, and the bio-oil activation energy ranged from 1.22×104 to 3.34×104 J/mol. Moreover, four models with five compounds (methanol, water, ethanol, furfural, and phenol) were established to study the bio-oil evaporation process. By comparing the TG-DSC results of bio-oil and its models at 30 °C/min, it was shown that the optimal model was model 2, which has the following chemical composition: methanol (27.10 wt.%), water (44.96 wt.%), ethanol (16.24 wt.%), furfural (4.40 wt.%), and phenol (7.30 wt.%). Model 2 exhibited a minimal relative error in dynamic parameters and characteristic curve parameters. The errors for activation energy of the TG, activation energy of the DSC, maximum endothermic rates, and the total of the heat absorption were 3.04%, 5.88%, 2.49%, and 1.06%, respectively.

Three different types of recycled polyurethane (PUR) material, two in powder form from a pulverizing process (one < 50 µm and one < 250 µm) and one in polyol form from a glycolysis process, were used as substitutes for polymeric methylene diphenyl diisocyanate (pMDI) resin at 5%, 15%, and 30% ratio, respectively, to replace the pMDI resin for particleboard manufacturing at 8% resin loading. The reactions between pMDI resin and recycled PUR powder and polyol were investigated with Fourier transform infrared (FT-IR) spectroscopy. It was found that 5% substitution of pMDI with recycled PU powder of < 50 µm resulted in significantly higher panel internal bonding (IB) strength than pure pMDI resin, which also tended to increase panel modulus of rupture (MOR), and modulus of elasticity (MOE). Polyol did not show advantages over PUR powder in particleboard application. Increasing the size of recycled PUR powder from < 50 µm to < 250 µm decreased the panel IB, which also tended to decrease MOR and MOE. Recycling PUR materials in either powder or polyol form in particleboard manufacturing did not improve panel thickness swelling, but did appear to improve panel water absorption.

Hydrophobically modified celluloses were prepared by the esterification of monocarboxycellulose (MCC) and carboxymethylcellulose (CMC) with methanol, followed by the amino-de-alkoxylation of the methyl esters with n-octadecylamine. These cellulose derivatives were fed at 30 and 60 g/kg for 4 weeks to female rats. The diets were supplemented with palm fat (60 or 50 g/kg) and cholesterol (0 or 10 g/kg). There was no significant effect of amidated celluloses on the feed intake or body weight of rats. Both MCC and CMC derivatives significantly decreased the concentrations of cholesterol present in the serum and liver. The supplementation of diets with hydrophobically modified celluloses tended to increase fecal concentrations of cholesterol and coprostanol and significantly increased fecal concentrations of total neutral sterols. In rats fed diets containing cholesterol, the total serum cholesterol correlated negatively with the fecal concentrations of neutral sterols. It can be concluded that MCC-C18 and CMC-C18 are effective cholesterol-lowering agents.

Larix spp., a wood species of low dimensional stability, was heat-treated in nitrogen at 180 to 210 °C for 6 h. Changes in the thermal decomposition and combustion behaviors of the wood after heat treatment were investigated by TGA, SEM, FTIR, and cone calorimetry. TGA confirmed the loss of hemicellulose from heat-treated Larix spp. Small cracks in the cell wall and loss of resin from the vessels of heat-treated wood were observed by SEM. Hemicellulose degradation within the heat-treated samples was indicated by decreased intensities of typical O-H and C=O stretching vibration peaks in the FTIR spectra. The HRR and MLR curves of treated wood were much lower than those of the untreated ones, which is preferable for fire safety. However, the time to ignition of treated samples decreased from 22 to 13 s and the total smoke production increased by 4.76 and 43.3% for 180- and 210 °C-treated samples, respectively, a detrimental effect on fire safety. To determine the influence of heat treatment on the combustion behaviorof Larix spp., the fire safety properties of heat-treated wood (such as wood structure building, furniture, and floors) must be studied further.

This article deals with the determination of the cyclic loading effect on the elastic modulus (Em) of beech solid and laminated wood at various thicknesses while bent in the radial direction. To identify the modulus of elasticity, a three-point static bending test was carried out. The monitored characteristics were compared for the bodies under cyclic stress vs. bodies not subject to cyclic stress. Results showed no significant effect of cyclic loading on the laminated wood elastic modulus values. Conversely, cyclic loading significantly (95% confidence interval) affects the modulus of elasticity values for solid wood. A significant impact of thickness has been observed for both types of material. The results demonstrate that the elastic modulus values decrease with increasing thickness after cyclic loading.

decreased following the first three-week infestation. Nano-indentation measurements revealed that the average MOE of infested larch flakes decreased from 24.0 to 17.1 GPa and the average hardness declined from 528.47 to 427.87 MPa following 12 weeks of infestation. After the first three weeks, the relative crystallinity, surface area, and micropore area of the infested samples increased. These parameters decreased after three weeks had elapsed. Changes in the absorption peaks observed in FTIR explained that the first three-week infestation had a strong effect on the mass loss and strength changes. This suggests that white rot fungus intensely attacked the lignin component of the biomass during the first three weeks of infestation.

China boasts a large production, import, and export volume of harvested wood products (HWP). The production, trade volume, and carbon stock of HWP can be used as valuable reference data for the economic growth and the participation of China in climatic negotiation. This research counts the production of major Chinese HWP between 1961 and 2012 according to the HWP classification standards of the Food and Agricultural Organization. The total forestry production value of China reached RMB 3,950 billion in 2012. The total forestry production value and the HWP production of China have been rising steadily. By applying the carbon accounting model of HWP under the stock change approach, this research estimates and analyzes the carbon stock of Chinese HWP from 1961 to 2012. The development of Chinese HWP inventories within this period can be roughly divided into three phases, which show a general uptrend. In 2012, the total carbon stock of Chinese HWP reached 888.01 million tons, whereas the annual increment of Chinese HWP reached 50.78 million tons. Therefore, HWP significantly contributes to the positive growth of Chinese carbon stock.

The influence of buffers, as well as inhibitors such as formic acid, furfural, HMF, guaiacol, and vanillin, on ethanol formation was investigated. Compared to phosphoric buffer, the acetic and citric buffers were less inhibitory on ethanol fermentation. The addition of formic acid (2.5 g/L) to the buffer reduced the ethanol yield by 8%. Guaiacol (3 g/L) and vanillin (2.5 g/L) decreased ethanol production by 50% and 20%, respectively. Furfural and HMF delayed the yeast fermentation without reducing the total yield. The fermentation was seriously inhibited by the mixture of furfural (1 g/L), HMF (1 g/L), formic acid (1 g/L), vanillin (1 g/L), and guaiacol (1 g/L). The ethanol yield of the fermentation based on enzymatic hydrolyzate from treated biomass was 82%. The addition of 1 g/L MgSO4 as a shielding protector rehabilitated nearly 100% of the total yield.

Mercerized pulp is widely used in the filter paper industry. But the major challenge facing users of the pulp is its difficult dispersion in water. It was found that by applying a suitable degree of beating it was possible to achieve better dispersion than the original pulp. The beating degree before and after beating was almost the same. But the properties of filter paper were greatly improved after beating, especially for the formation index and burst index. The morphology of beaten fibers was analyzed by SEM with both the freeze-drying and air drying sample preparation process. The results showed that the primary cell wall of the beaten mercerized pulp fibers were swollen and partly peeled from the fiber main body after beating, as revealed by micrographs obtained after freeze-drying. The results suggest that the improvement of the fiber dispersion in water was caused by these changes on the fiber surface.

This study was conducted to evaluate the suitability of date palm midribs as an alternative source for energy production. The physical properties, chemical constituents, and fuel characteristics of the midribs of five common date palm cultivars (Barhi, Khalas, Khodry, Sukkari, and Sullaj) were determined. In addition to the frond base, the midribs were divided into three distinct parts (base, middle, and top) along the frond. The results showed that both the fibre saturation point and volumetric shrinkage of the date palm midribs were much higher than those of solid wood. There were significant differences in all of the chemical constituents of the midribs between the five date palm cultivars. The date palm midribs were characterised by higher levels of extractives (19.3% for Barhi to 21.7% for Sullaj) and ash contents (3.3% for Khodry to 5.8% for Khalas). The other chemical constituents were within the ranges found for other lignocellulosic materials, including softwood and hardwood. The heating values for the midribs ranged between 17.30 MJ/kg for the Barhi cultivar and 17.89 MJ/kg for the Khodry cultivar. The higher ash content and lower density of date palm midribs makes them less desirable for energy production. It can therefore be concluded that the frond base is not suitable for energy production.