Research Articles

Potash alkali and metal contents of ashes obtained from peels of six varieties of Nigeria Musa species were investigated. The varieties of Musa species – Musa paradisiaca (plantain), Musa ‘Gross Michel’ (Igbo banana), M.sapientum L. (paranta), Musa ‘Wild Banana’ (omini), Musa ‘Red’ (sweet banana), and Musa ‘Fugamo’ (somupeke), were investigated. The moisture, dry matter, ash and alkali contents; concentration of metals in the ashes and in the contents extracted with water from the ashes; and the ratio of potassium to other metals in the ashes and in the corresponding extracts were determined. Moisture contents ranged from 80.9 to 86.7%; dry matter content, 13.3 to 19.1%; ash content, 6.3 to 12.0%; alkali content, 69.0 to 81.9% of ash and 4.7 to 9.6% of dry sample. Samples ranged between 2.60 and 720mg/kg and in the corresponding extracts, BDL to 500.49mg/kg; ratio of concentration of potassium to other metals in the samples, 0.6 to 395; and in the extracts, 0.5 to 313. Gross michel showed the highest concentration of K (750mg/kg) while omini banana gave the lowest average value (112.70mg/kg).

The paracrystallinity of cellulose samples was studied with a complex of investigation methods including X-ray, NMR, sorption, calorimetry, and some others. It was found that the paracrystalline fraction of cellulose is located on the surface of crystallites as thin monomolecular layers having an average thickness of 0.4 nm. The paracrystalline surface layers have distorted and loose packing that is characterized by a high distortion parameter δp = 0.18, increased specific volume Vp=0.664 cm3/g, and decreased specific gravity ρp= 1.51 g/cm3. The paracrystalline fraction of the crystallite can be quantified by the parameter ( α ), which has an expressed influence on some properties of cellulose. Increasing of the α-value causes expansion of inter-plane distances in the C1 unit cell, as well as promotes mercerization and dissolution of cellulose.

Three lignins: Indulin AT, LignoboostTM, and Acetocell lignin, were characterized and pyrolyzed in a continuous-fed fast pyrolysis process. The physical and chemical properties of the lignins included chemical composition, heat content, ash, and water content. The distributed activation energy model (DAEM) was used to describe the pyrolysis of each lignin. Activation energy distributions of each lignin were quite different and generally covered a broad range of energies, typically found in lignins. Process yields for initial continuous-fed fast pyrolysis experiments are reported. Bio-oil yield was low, ranging from 16 to 22%. Under the fast pyrolysis conditions used, the Indulin AT and LignoboostTM lignin yielded slightly more liquid product than the Acetocell lignin. Lignin kinetic parameters and chemical composition vary considerably and fast pyrolysis processes must be specified for each type of lignin.

Corporate environmental sustainability calls for sustainable product manufacturing with less creation of waste material or increased reuse of waste materials. One example is the use of keratin fiber from the poultry industry and cotton linter from the textile industry for paper and tissue manufacturing. In this paper, the feasibility of using these waste fibers to make paper was demonstrated in handsheets. The properties of these handsheets were compared to the properties of handsheets made with standard bleached eucalyptus tropical hardwood fibers. A blend of cotton linter and keratin fibers at 80/20 and 60/40 ratios showed a 59% and 73% improvement in sheet bulk, respectively, compared to eucalyptus handsheets. Similarly, air permeability of the cotton / keratin fiber handsheets improved 414% and 336%, respectively, versus the eucalyptus. However, the tensile index of the cotton and keratin fiber blends was lower than the eucalyptus sheets. There was no remarkable difference in water absorbency up to 20% keratin fiber. Above 20% of keratin fibers the water absorbency started to decrease, which is likely attributable to the hydrophobic nature of the protein-based keratin fiber.

This paper reports results concerning characterization and improvement of biological quality of beechwood prehydrolysate in order to adapt the Candida Scottii yeast to this nutritive medium. Some difficult aspects caused by the presence of lignin compounds in the prehydrolysate are mentioned. Studies carried out also made it possible to evaluate yeasts as regards the chemical composition and their nutritive value, tested in case of a mixed fodder used for chicken breeding.

This study was carried out to identify an appropriate alkaline pulping condition for Malaysia cultivated kenaf (Hibiscus cannabinus L.). The chemical composition of the kenaf bast and core fibers, and also whole stalk with different growing time were examined prior to pulping attempts. The results of various soda-AQ pulping showed that the degree of carbohydrate degradation and delignification increased with the increase of active alkali and cooking temperature, but decreased with the increase of liquor to material (L:M) ratio. The most satisfactory properties of pulp and handsheets from bast could be attained by employing soda-AQ pulping with 19.4% active alkali, 0.10% AQ, and L:M ratio of 7:1 cooked for 2 hours at 160˚C. Besides, it was also found that a mild alkaline pre-impregnation prior pulping improved the pulp viscosity and handsheets’ strength properties, especially the tensile index and folding endurance effectively. Moreover, among the three alkaline pulping processes—kraft, kraft-AQ, and soda-AQ—the results of pulp and handsheet properties showed that the soda-AQ pulp was comparable or even slightly of higher quality than the kraft pulps. Between the unbeaten bast and core soda-AQ handsheets, the strength properties of the core were higher than the bast, as the thin-walled core fibers exhibited much better conformability than the thick-walled bast fibers.

Forest industries look for multiple utilizations for their timber production. In Brazil, the genus Eucalyptus has a great potential for solid wood products; however, only a small amount of Eucalyptus is used as sawn timber. About 50% of the log volume ends up as waste during mechanical processing, resulting in serious economic and environmental problems. In most cases, such residue is discarded at random or used as fuel, and in this context the sustainable management of processing industrial waste is an urgent necessity. Parallel to this, Eucalyptus has not been employed for small wooden object (SWO) production. Hence, the aim of this work was to evaluate the performance of small wooden objects produced with Eucalyptus urophylla, E. camaldulensis, and E. grandis waste from sawmilling. Brazilian craftsmen manufactured SWOs with Eucalyptus, and these crafted objects were presented at exhibits and trade fairs for assessment. The proposed small wooden objects made with Eucalyptus residues exhibited satisfactory performance and achieved excellent acceptance by the visitors. This work gave evidence that the use of sawmill waste as raw material for small wooden object manufacture has potential to generate income for economically underprivileged communities near to a plantation.

The bending moment capacity was studied under the diagonal tensile and compression loadings of miter corner joints with dovetail fitting in frames made with medium density fiberboard (MDF). The influence of the type of adhesive in the joints with dovetail fitting on bending moment capacity under diagonal tensile and compression loading were considered, and the joints without adhesive were compared. A total of 80 each miter frame corner joint specimens with dovetail fitting were made. Polyvinyl acetate (PVAc), polyurethane (PU), and cyanoacrylate (CA) adhesives were used, and 20 specimens were prepared without adhesive (WA) with dovetail fitting. MDF was used as a frame material, as in normal practice. The specimens were subjected to diagonal tensile and compression loadings in accordance with ASTM-D 143-94. The data were analyzed statistically. The highest bending moment capacity under diagonal tensile loading (46.09 Nm) was obtained in the specimens bonded with CA adhesive and the highest bending moment capacity under diagonal compression loading (72.04 Nm) was obtained in the specimens glued with PVAc adhesive. Other than this, since there is no difference between these and the unbonded joints, the PU adhesive was not effective in increasing the bending moment capacity under diagonal tensile loading, and the PU and CA adhesives were not effective in increasing the bending moment capacity under diagonal compression loadings.

Superabsorbent polymer was prepared by graft polymerization of acrylic acid onto the chain of cellulose from flax shive by using potassium persulfate (KPS) as an initiator and N,N’-methylenebisacrylamide (MBA) as a crosslinker under microwave irradiation. SEM photographs were also studied for more information about the shive, cellulose from shive, and the superabsorbent polymer. The structure of the graft copolymer was confirmed by FT-IR spectroscopy and thermogravimetric analysis (TGA). The biodegradability in soil was measured at 32 and 40 oC. The polymer was porous, and thermal stability of the polymer was observed up to approximately 200 oC. FT-IR analysis indicated that acrylic acid in polymer was successfully grafted onto the cellulose. The graft copolymer was found to be an effective superabsorbent resin, rapidly absorbing water to almost 1000 times its own dry weight at pH around 7.3. The water absorbency in 0.9% NaCl, KCl, FeCl3 solutions and urine were 56.47 g/g, 54.71g/g, 9.89g/g and 797.21g/g, respectively. The product biologically degraded up to 40% at 40 oC in 54 days, which shows good biodegradability.

Coastal Bermuda grass (CBG) is an agricultural residue with considerable potential as a feedstock for lignocellulosic-based ethanol. The treatment of biomass with water at high temperature, termed autohydrolysis, can be used to recover sugars in the filtrate and to improve enzyme digestibility of the pretreated solids. The effect of a two- stage autohydrolysis process with respect to total sugar recovery relative to a one stage process was investigated. CBG was subjected to lab scale one-stage (150, 160, and 170 °C) and two-stage (150/170 °C and 160/170 °C) isothermal autohydrolysis processes followed by enzyme hydrolysis on the residual solids with different loadings (5 to 30 FPU/g). Two-stage autohydrolysis (160/170 °C) solubilized 94.2% of the hemicellulose based on the original CBG material but only 17.7% of the cellulose and 30.4% of the lignin. Increases in the severity factor (a combination of time and temperature) of autohydrolysis pretreatments decreased the recoverable carbohydrates and total solids. Two-stage autohydrolysis enhanced enzyme digestibility of the cellulose in pretreated solids relative to one-stage autohydrolysis, especially at higher values of FPU/g. The overall total theoretical sugar recovery achievable by the two stage process was 57.8% and for the one stage process only 51.6% with 30 FPU/g. This marginal increase would have to be considered relative to increased complexity of operations when deciding whether to implement one or two stage autohydrolysis.