Volume 14 Issue 4

A biocomposite was successfully prepared by blending montmorillonite (MMT)/hemicellulose from oil palm empty fruit bunches (OPEFB) with carboxymethyl cellulose (CMC) through solution casting. The composite was characterized by scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results displayed good compatibility between the mixtures of the blended MMT/hemicellulose and CMC due to the hydrogen bonding and electrostatic interaction. There was an improvement in the thermal analysis through their thermogravimetry analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC), mechanical properties (tensile strength and tensile modulus),and water vapor permeability (WVP). The best values of tensile strength and tensile modulus of 47.5 MPa and 2.62 MPa, respectively, were obtained from 60H-40CMC-MMT nanocomposite films. The results showed that the mixture of the blended MMT/hemicelluloses and CMC produced a robust nanocomposite film with improved physical and mechanical properties, demonstrating that it is a promising candidate for green packaging applications.

Thermally treated wood is widely used for construction, furniture, and flooring because it has better dimensional stability in outdoor conditions. There is a close relationship between the mechanical properties of thermally treated wood cell walls and the performance of its products. The hardness (H) and reduced elastic modulus (Er) of larch (Larix gmelinii) and red oak (Quercus rubra) wood cell walls were investigated via nanoindentation. The results showed that the larch and red oak wood specimens had different nanomechanical properties. The Er in the larch wood initially increased with a maximum value of 22.4 GPa at 225 °C, then rapidly decreased after 300 °C with a minimum value of 5.7 GPa at 350 °C. The Er in the red oak wood appeared to have a mild decline. The H in both wood species visibly increased with the thermal treatments due to the reduction of organic wood polymers and the increase of inorganic carbon materials.

The material basis and degradation of the terpenoids were investigated in Pinus massoniana sawdust during the composting process. In order to better utilize P. massoniana sawdust for the culturation of edible fungus, three treatments were designed according to the amount of brown sugar that was added: 4% (A1), 5% (A2), and 6% (A3). The brown sugar was added based on the dry weight of the P. massoniana sawdust. The results showed that the brown sugar addition of 5% yielded the fastest heating rate of composting and the longest temperature duration above 60 °C. The gas chromatography-mass (GC-MS) analysis showed that the amount of brown sugar did not affect the degradation of the terpenoids. The relative terpenoid content decreased from 3.89% to 2.10% and 0.31% after 30 d and 60 d of composting, respectively. Fourier transform infrared (FTIR) analysis indicated that the terpenoids decomposed a lot throughout the composting process. The mycelium cultivation demonstrated that the P. massoniana sawdust treated with 30 d of composting promoted the growth of edible fungi.

In order to promote plantation establishment of Larix gmelinii var. olgensis (syn. L. olgensis A. Henry), a ‘near threatened’ species, the wood and lumber properties were preliminary investigated for five trees from two clones of 57-year-old trees planted in Japan. The mean value of dynamic Young’s modulus of logs was 10.16 GPa. The mean values of annual ring width, latewood percentage, basic density, MOE, and MOR of five sample trees were 2.1 mm, 29.3%, 0.47 g•cm-3, 8.06 GPa, and 60.4 MPa, respectively. In addition, the MOE and MOR of 2 by 4 lumber were 10.43 GPa and 42.4 MPa, respectively. These values were similar to those obtained from other Larix species. Thus, construction lumber could be produced from the wood from plantation grown L. gmelinii var. olgensis.

Changes in chemical composition and structure of corncob lignocellulosic biomass were investigated relative to pretreatment and anaerobic digestion. The pretreatment involved 1% and 3% sodium hydroxide, 3% and 7% sulphuric acid, as well as medium and high temperature extrusion (in 110 °C and in the range from 140 °C to 160 °C). The chemical components content was studied using a gravimetric method, whereas structure and relations between the carbohydrate and lignin participation were investigated using Fourier transform infrared spectroscopy. It was determined that the chemical treatment, both acidic and alkaline, changed the chemical composition of corncob more significantly than the extrusion. Alkaline pretreatment contributed to significant delignification, while acidic pretreatment reduced the share of hemicelluloses and increased the proportion of lignin, the so-called “pseudolignin”. The composition of corncob (control and after pre-treatment) was changed after anaerobic digestion, i.e., a decreased carbohydrate substance content and a significantly increased lignin content. FTIR analysis showed changes in their structure. Although the control corncob differed from that processed by various pretreatment methods, the chemical composition of the digested pulp obtained from them was similar. The NaOH pretreatment was judged to be the preferred method for delignification of the raw material.

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.