Volume 6 Issue 2

High performance anion-exchange chromatography with pulse ampero-metric detector (HPAEC-PAD) is a reliable method to systematically determine the sugar contents in pulp and paper waste streams, including bleaching and extraction liquors. We used the same method to determine the sugar content of industrially produced pre-hydrolysis liquor (PHL) from a kraft-based dissolving pulp production process. The analysis showed that the traditional method cannot be applied for sugar analysis, and an improvement on the method was required. In fact, the presence of furfural in the PHL sample was the reason for the required modification. It was noted that the removal of furfural via evaporation could improve the reliability of the HPAEC technique for sugar assessments. If the concentration of furfural was higher than 0.045% (wt.) in the PHL, the error introduced in the sugar analysis was profound. Also, the industrially produced PHL contained more furfural than the laboratory produced PHL under the same hydrolysis conditions. Consequently, the concentration of furfural in the PHL should be taken into account for sugar analysis using the HPAEC technique.

The present study investigates cellulose phosphate from oil palm biomass (OPEFB-CP) as a potential biomaterial. To this effect, oil palm biomass microcrystalline cellulose (OPEFB-MCC) was phosphorylated using the H3PO4/ P2O5/ Et3PO4/ hexanol method. Characterization of OPEFB-CP was performed using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared (FTIR) spectroscopy, thermogravimetry (TG), and X-ray diffraction (XRD). The cytotoxicity evaluation of OPEFB-CP was conducted on mouse connective tissue fibroblast cells (L929) using MTS Assay analysis, and the proliferation rate of OPEFB-CP on L929 was assessed by the indirect extraction method, whilst mineralization assessment was carried out by immersion of the material in Simulated Body Fluid (SBF) for 30 days. Disruption of the crystalline structure of OPEFB-MCC, changes in surface morphology of OPEFB-CP, the presence of new FTIR peaks on OPEFB-CP at 2380 cm-1 and 1380 cm-1, and a smaller rate of mass loss of OPEFB-CP are indications of a successful grafting of phosphate groups. OPEFB-CP showed non-cytotoxic in vitro biocompatibility after 72h exposure with an IC-50 value 45mg/mL and a proliferation rate of up to 8 days with no change in cells morphology below the IC-50 concentration. Apatite formation was observed on OPEFB-CP surfaces after 30 days in SBF with a Ca:P ratio of 1.85.

Polypropylene/wood flour composites having different nanoclay and glass fiber contents were fabricated by melt compounding and then injection molding. The physical and mechanical properties were evaluated. The results showed that the tensile modulus and tensile strength of the PP/wood flour composites increased with increasing glass fiber content. However, the impact strength of the PP/wood flour composites progressively decreased with increasing glass fiber content. Dimensional stability of the composites could be improved by increasing the glass fiber content. Also, results indicated that the tensile modulus and tensile strength of composites increased with increase of nanoclay up to 4phc and then decreased. However the impact strength and water absorption of the composites decreased with increasing the nanoclay loading. The morphology of the nanocomposites was examined by using X-ray diffraction (XRD). Morphological findings revealed an intercalated form in the sample with 4 per hundred compounds (phc) concentration of nanoclay, which implies the formation of an intercalated morphology and better dispersion than 6phc, and the d-spacing of clay layers were improved in the composite in the presence of compatibilizer. This project has shown that the composites treated with glass fiber and nanoclay will be desirable as building materials due to their improved stability and strength properties.

This paper presents spectroscopic, thermal, and morphological properties of two bamboo species viz. Gigantochloa brang and Gigantochloa wrayi. The nature of cell wall structure and distribution of vascular bundles in G. brang and G. wrayi were studied by scanning electron microscopy and transmission electron microscopy techniques. Gigantochloa spp. at various positions and locations showed identical thermal stability and are stable up to 200 °C. The decomposition of cellulose and hemicelluloses component of the culm occurred between 220 °C and 390 °C, while the degradation of lignin takes place above 400 °C.

The appropriate pitch control is critical in many pulp and paper operations. One of the important approaches for pitch control is to use synthetic polymers. In this paper, we provide evidence from differential scanning calorimetry (DSC) analysis that the pitch deposits formed with polymers, such as polyDADMAC and CPAM, had better thermal stability than those without these polymers. Metal cations also affected the thermal stability of deposited pitch, depending on their valencies. The confocal laser scanning microscope (CLSM) was used to determine the distribution of pitch in the handsheets, and the results showed that polymers can aggregate pitch particles, which facilitates the retention of pitch on the paper sheet.

The pyrolysis of tobacco residue in the presence of metal oxides and metal chlorides was investigated at 300, 400, and 500 °C. Catalysts used were Al2O3, Fe2O3, AlCl3, and SnCl4 in concentrations from 1 up to 5 wt% of the tobacco residue feedstock. The amount of catalysts and the pyrolysis temperature had significant effect on both product distributions and bio-oil composition. The catalytic effect was dominant at the lowest temperature (300 °C). The pyrolysis temperature was decreased by 200 °C compared to the thermal run. Bio-oil contained a large variety of compounds. Nicotine, which is very stable until temperatures in excess of 600 °C, could be degraded at the lowest temperature by using 1 wt% of AlCl3 and 1 wt% of Fe2O3.

Cork is the bark of the cork oak tree (Quercus suber L), a renewable and biodegradable raw bioresource concentrated mainly in the Mediterranean region. Development of its potential uses as a biosorbent will require the investigation of its chemical composition; such information can be of help to understand its interactions with organic pollutants. The present study investigates the summative chemical composition of three bark layers (back, cork, and belly) of five Spanish cork samples and one cork sample from Portugal. Suberin was the main component in all the samples (21.1 to 53.1%), followed by lignin (14.8 to 31%), holocellulose (2.3 to 33.6%), extractives (7.3 to 20.4%), and ash (0.4 to 3.3%). The Kruskal-Wallis test was used to determine whether the variations in chemical composition with respect to the production area and bark layers were significant. The results indicate that, with respect to the bark layer, significant differences were found only for suberin and holocellulose contents: they were higher in the belly and cork than in the back. Based on the results presented, cork is a material with a lot of potential because of its heterogeneity in chemical composition.

Medium density fiberboard (MDF) is an engineered wood product formed by breaking down selected lignin-cellulosic material residuals into fibers, combining it with wax and a resin binder, and then forming panels by applying high temperature and pressure. Because the raw material in the industrial process is ever-changing, the panel industry requires methods for monitoring the composition of their products. The aim of this study was to estimate the ratio of sugarcane (SC) bagasse to Eucalyptus wood in MDF panels using near infrared (NIR) spectroscopy. Principal component analysis (PCA) and partial least square (PLS) regressions were performed. MDF panels having different bagasse contents were easily distinguished from each other by the PCA of their NIR spectra with clearly different patterns of response. The PLS-R models for SC content of these MDF samples presented a strong coefficient of determination (0.96) between the NIR-predicted and Lab-determined values and a low standard error of prediction (~1.5%) in the cross-validations. A key role of resins (adhesives), cellulose, and lignin for such PLS-R calibrations was shown. PLS-DA model correctly classified ninety-four percent of MDF samples by cross-validations and ninety-eight percent of the panels by independent test set. These NIR-based models can be useful to quickly estimate sugarcane bagasse vs. Eucalyptus wood content ratio in unknown MDF samples and to verify the quality of these engineered wood products in an online process.

Nowadays agricultural wastes represent an alternative source of renewable raw materials. Different processes can be applied to these alternative materials to separate their components and obtain chemical products with high added value, such as bioethanol, organic acids, monomers, and biopolymers. The main objective of this work is to study the extraction of hemicelluloses from corn stalks using different reagents [H2SO4, HNO3, HCL, CH3COOH, CF3COOH, Ca(OH)2, NaOH]. The raw material was characterized and fractionated with autoclave hydrolysis processes (121 ºC, 1:20 solid/liquid ratio, 60 min, pH = 4 or 8). Monomeric sugars concentration, TDS, MO, MI, density, and final pH of the hydrolysate were determined. Hemicelluloses were precipitated and analyzed by different techniques (FTIR, TGA and GPC). The highest yield of hemicelluloses extraction was achieved by sulphuric acid (0.98 g/L total sugar content) and the less effective reagent was Ca(OH)2 (0.52 g/L total sugar content).

Variations in average tracheid dimensions (such as length, diameter, lumen diameter, and wall thickness) and its biometrical ratios including slenderness ratio, flexibility ratio, and Runkell ratio, oven-dry and basic density, longitudinal, radial, tangential, and volume shrinkage, maximum moisture content, and porosity of cypress trees wood (Cupressus sempervirens L.var. horizontalis), which was cultivated in the north of Iran, were studied from the pith to bark (radial position), and along the stem from the base upwards. To measure the mentioned traits, the test specimens were prepared from three stands and 9 discs at different height levels (5, 25, and 50% of the total tree height) based on ASTM-D143 standard. Results indicated that the tracheid length, tracheid cross-sectional dimensions, and its biometrical ratios irregularly varied at each height level, along the stem from the bottom to top, but within the discs, at the same height level biometrical traits in the radial position regularly increased from the pith to bark. Within the tree, wood oven-dry and basic density, longitudinal, radial, tangential, and volume shrinkage varied at each height level, decreasing along the stem from the base upwards. Within the discs, at the same height level, wood density and shrinkage, except for longitudinal shrinkage in the radial position, increased from the pith to bark. The maximum moisture content and porosity varied at each height level, increasing along the stem from the bottom to the top of the tree. Moreover, within the discs, at the same height level in the radial direction porosity decreased and maximum moisture content increased except for at 5% of height level from the pith to bark.