Volume 6 Issue 4

Xylose-extracted corncob residue (X-ER), a byproduct from the xylose production industry, is a potential cellulose-rich energy resource. However, attempts to achieve large-scale production of cellulosic ethanol using X-ER have been unsatisfactory due to a lack of understanding of the substrate. This study presents the first characterization of the X-ER to evaluate its potential utilization in the sequential production of cellulosic ethanol. The current dilute acid treatment procedures used for the corncobs by the xylose-production industry were insufficient for efficient deconstruction of cellulose structure to release available sugars for subsequent cellulosic ethanol conversion. After a secondary dilute acid hydrolysis of the X-ER, an additional 30% hemicellulose was recovered. In addition, a more efficient enzymatic hydrolysis of X-ER was observed resulting in a significantly higher yield of glucose conversion compared with an untreated X-ER control. These results suggest X-ER can be utilized for cellulosic ethanol production. However, improved corncob pretreatment procedures are needed for economical cellulosic ethanol conversion.

A novel manganese peroxidase (MnP) produced by an indigenous white rot fungal strain Trametes versicolor IBL-04 in solid state medium of corncobs was purified and characterized. The fungus produced 964U/mL MnP in the presence of additional carbon (glucose) and nitrogen (yeast extract) supplements added at a C:N ratio of 25:1, 1mM Tween-80 (1mL), 1mM MnSO4 (1mL), and 1mM CuSO4 (1mL). The MnP was purified by ammonium sulfate fractionation (65% saturation) and dialysis, followed by Sephadex G-100 gel filtration chromatography. Purification procedures resulted in 2.4-fold purification with an overall yield and specific activity of 3.4% and 660 U/mg, respectively. The purified MnP was monomeric of molecular weight of 43 kDa, showing a single band on sodium dodecyl sulfate poly acrylamide gel electrophoresis (SDS-PAGE). The enzyme was optimally active at pH 5 and 50oC and was stable for 1 h over a broad range of pH (4-7) and temperature (40-65oC). Kinetic constants KM and Vmax of purified MnP were 70 µM and 540 U/mL for MnSO4 substrate. The effect of possible activators and inhibitors of enzyme were also investigated, and it was observed that EDTA, Cystein, and Ag+ caused MnP inhibition and inactivation to different extents, whereas MnP was activated by 4 and 3 mM of Cu2+ and Fe2+, respectively. High thermo-stability, low KM and high Vmax features of this novel MnP isolated from culture filtrate of T. versicolor IBL-04 suggests its suitability for various industrial and biotechnological applications.

Finland currently has tremendous enthusiasm to increase decentralised pellet production alongside of large-scale factories. The aim of research is to promote the development of eco-/cost-efficient Nordic wood-based pellet production by means of multidisciplinary research. Using Finnish conifer stem wood (bark-free Scotch pine sawdust and shavings) as a model raw material, the total functionality of a pilot-scale pellet facility combined with an extensive chemical toolbox was tested in this study to promote future development of eco- and cost-efficient wood-based pellet production in both quantitative and qualitative senses. Lignosulphonate, residual potato flour, and potato peel residue were used as adhesive binding agents. A pilot-scale pellet facility was equipped with a data logger for temperature and power measurements. The chemical toolbox included also novel specific staining and optical microscope methods and respirometric BOD Oxitop measurements. The results showed that adhesive binding agents increased the quality of pellets and changed inorganic characteristics, but did not have a significant effect on their calorimetric heat values. Lignosulphonate even increased the rate of production. Valuable information about both the pelletizing process and pellets is necessary in the future when developing good-quality pellets, a prime biofuel, from low-value and/or moist biomass that has undergone a cost-efficient drying process.

In order to determine the quantitative relationship between sheet strength and lignin coverage at the fiber surface, CTMP was blended with softwood bleached kraft pulp (BKP), refined softwood BKP, and hardwood BKP. The morphology of the fibers, fibers properties, fiber surface components and relative bonded area of sheets were investigated. Multi-linear regression equations of tensile strength index and internal bond strength were established. The results indicated that unbleached aspen CTMP fiber surfaces were covered by granules of lignin, and BKP fiber surfaces were predominated covered by microfibrils. Fiber properties have a significant impact on tensile strength index. RBA had a greater impact on IBS than lignin coverage. For the pulp samples tested, a 1% increase in lignin coverage at fiber surfaces would lead to a 0.48N·m/g decrease in tensile strength index and 5.32×10-3 J/m2 decrease in internal bond strength.

Microfibrillated celluloses (MFCs) have mechanical properties sufficient for packaging applications, but they lack water vapor barrier properties in comparison to petroleum-based plastics. These properties can be modified by the use of mineral fillers, added within the film structure, or waxes, as surface coatings. In this investigation it was found that addition of fillers resulted in films with lower densities but also lower water vapor transmission rates (WVTR). This was hypothesized to be due to decreased water vapor solubility in the films. Associated transport phenomena were analyzed by the Knudsen model for diffusion but due to the limited incorporation of chemical factors in the model and relatively large pore sizes, accurate prediction of pore diameters for filled films was not possible with this model. Modeling the filled-films with Fick’s equation, however, takes into account chemical differences, as observed by the calculated tortuosity values. Remarkably, coating with beeswax, paraffin, and cooked starch resulted in MFC films with water vapor transmission rates lower than those for low density polyethylene. These coatings were modeled with a three-layer model which determined that coatings were more effective in reducing WVTR.

Properties of composite boards from oil palm frond agricultural waste were researched. Phenol and urea formaldehyde resins were used as the binders. The oil palm fronds were obtained from 20 year-old trees in an oil palm plantation in Kota Belud, Sabah. The fronds were segregated into three groups of matured, intermediate, and young oil palm fronds and further subdivided into bottom, middle, and top sections. The leaflets and the epidermis were removed from the fronds before they were sliced longitudinally into thin layers. The layers were then compressed into uniform thickness of 2 to 3 mm. The layers were air-dried and later mixed with resins using 12 to 15% of phenol and urea formaldehyde and recompressed with other layers, forming composite boards. The composite boards samples were then tested for their physical and mechanical properties. Testing was conducted in accordance with the International Organization for Standardization (ISO) standard. The results for physical and mechanical properties showed that the oil palm composite boards were better than composite boards from oil palm trunks and slightly worse than the rubberwood. Statistical analysis indicated significant differences between composite boards made from each group and section, but no differences were observed in the type of resin used. The composite boards from oil palm fronds agricultural residues has the potential to be used as an alternative to wood to overcome the shortage in materials in the wood industry.

Funalia trogii and Trametes versicolor were grown on agro byproduct wheat bran moistened with various natural moistening agents, and their effects on laccase production under solid substrate condition were investigated. Laccase was the main enzyme detected under this condition. High levels of laccase activity were obtained with solid substrate cultures moistened with olive oil mill wastewater (OOMW) or alcohol factory wastewater (vinasse). Among the cultures without inducer, T. versicolor culture was detected as a more effective laccase producer than F. trogii culture. Copper and xylidine were used as laccase inducers, and copper induced laccase production more than xylidine. The maximum laccase activity was detected as 14.18 U/mL with F. trogii grown on wheat bran moistened with 5 mM CuSO4.5H2O added 25% vinasse. Azo dye decolorization activity of the supernatants from solid substrate cultures was also tested. While the use of 0.063 U/mL F. trogii laccase in reaction solution gave 66% decolorization in a minute, it was 14% for T. versicolor. This method can be a possible alternative for valorization of lignocellulosic materials and industrial wastewaters during solid substrate fermentation and for obtaining enzyme source with very high decolorization activity.

Xylo-oligosaccharides were obtained from Miscanthus x giganteus. The process was designed as a biorefinery scheme, which seeks the separation of the three main components: cellulose, hemicelluloses, and lignin. To extract the hemicelluloses, particularly xylans, in an efficient way, Miscanthus was subjected to autohydrolysis. The system was evaluated for the effects of temperature (160 to 200oC) and reaction time (15 to 60 min) on various parameters, reflecting the changes undergone during the process. The results showed that autohydrolysis is a suitable method for obtaining high yields of xylo-oligosaccharides, reaching values close to 65% of the dissolved xylans (based on the initial amount of potential xylose). Analysis of the process by using the severity factor (RO) allowed for the identification of a set of time-temperature values for which the fractionation was optimal.

and 3-methacryloxy-propyltrimethoxysilane (MPS) for the lack of compatibility with UF resin adhesive. The modified NCC was characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TG), and wetting property. and bonding strength of the UF resin adhesive with modified NCC were tested according to Chinese National Standards GB/T 17657-1999 and GB/T 9846-2004. The results of XRD, TG, and wetting property from NCC modified by APTES showed more significant improvements than that from NCC modified by MPS. The HCHO emission of UF resin adhesive with 1.5% NCC modified by APTESdecreasedby 53.2% and bonding strength increased by 23.6%, while the results from the NCC modified by MPS were 21.3% and 7.0%, respectively.

The main objective of this study was to explore the suitability of Vitis vinifera as a raw material and alkaline lignin as a natural binder for fiberboard manufacturing. In the first step, Vitis vinifera was steam- exploded through a thermo-mechanical vapor process in a batch reactor, and the obtained pulp was dried, ground, and pressed to produce the boards. The effects of pretreatment factors and pressing conditions on the chemical composition of the fibers and the physico-mechanical properties of binderless fiberboards were evaluated, and the conditions that optimize these properties were found. A response surface method based on a central composite design and multiple-response optimization was used. The variables studied and their respective variation ranges were: pretreatment temperature (Tr: 190-210ºC), pretreatment time (tr: 5-10 min), pressing temperature (Tp: 190-210ºC), pressing pressure (Pp: 8-16MPa), and pressing time (tp: 3-7min). The results of the optimization step show that binderless fiberboards have good water resistance and weaker mechanical properties. In the second step, fiberboards based on alkaline lignin and Vitis vinifera pulp produced at the optimal conditions determined for binderless fiberboards were prepared and their physico-mechanical properties were tested. Our results show that the addition of about 15% alkaline lignin leads to the production of fiberboards that fully meet the requirements of the relevant standard specifications.