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BioResources, Volume 5, Issue 1 February 2010
NOTE: Each current issue of BioResources continues to build as new articles are approved. ABSTRACTS Hubbe, M. A., and Buehlmann, U. (2010). "A continuing reverence for wood," BioRes. 5(1), 1-2. Our ancestors knew a great deal about wood. They had to in order to do well in life. Wood has played a dominant role in human infrastructure for many generations, and for most of that time woodcraft has depended on the decentralized knowledge passed down among families and guilds. This editorial, while celebrating the knowledge, skills, and insights of the woodworkers of past generations, also calls for a renewed attention to wood’s unique character, including characteristics that today are too often classified as “defects.” We may need to take lessons from generations past to truly derive the best value from wood resources. PDF Wang, Q., and Zhu, S. (2010). "Genetically modified lignocellulosic biomass for improvement of ethanol production," BioRes. 5(1), 3-4. Production of ethanol from lignocellulosic feed-stocks is of growing interest worldwide in recent years. However, we are currently still facing significant technical challenges to make it economically feasible on an industrial scale. Genetically modified lignocellulosic biomass has provided a potential alternative to address such challenges. Some studies have shown that genetically modified lignocellulosic biomass can increase its yield, decreasing its enzymatic hydrolysis cost and altering its composition and structure for ethanol production. Moreover, the modified lignocellulosic biomass also makes it possible to simplify the ethanol production procedures from lignocellulosic feed-stocks. PDF Shen, J., Song, Z., and Qian, X. (2010)."Possible trends of renewable organic fillers and pigments derived from natural resources for sustainable development of paper industry,"BioRes. 5(1), 5-7. The use of traditional inorganic fillers and pigments for both filling and coating applications in papermaking may have certain limitations in such aspects as recyclability and combustibility. Novel renewable organic fillers and pigments derived from natural resources can possibly be completely recyclable, combustible, biodegradable, and environmentally friendly, and they can potentially be used as substitutes for inorganic fillers and pigments to improve the recyclability and other properties of the paper products. Although there are still challenges lying ahead, the strategic significance of the use of renewable organic fillers and pigments for the sustainable development of papermaking industry is an indisputable and demonstrable fact. PDF Saritha, V., Maruthi, A., and Mukkanti, K. (2010). "Potential fungi for bioremediation of industrial effluents,"BioRes. 5(1), 8-22. Two fungi (unidentified) were isolated from soil and marine environ-ments. These isolates were used for bioremediation of pulp and paper mill effluent at the laboratory scale. The treatment resulted in the reduction of color, lignin, and COD of the effluent in the order of 78.6%, 79.0%, and 89.4% in 21 days. A major part of reductions in these parameters occurred within 5 days of the treatment, which was also characterized by a steep decline in the pH of the effluent. The enzyme activity of these fungi was also tested, and the clearance zone was obtained in the plate assay. PDF Zhang, X.., Tu, M., Paice, M., Sacciadis, G., Jiang, Z., Jemaa, N., and Thibault, A. (2010). "Bioconversion of knot rejects from a sulphite pulp mill to ethanol," BioRes. 5(1), 23-42. Knot rejects obtained from pulp screening after sulphite pulping are difficult to dewater, which makes landfilling expensive and burning inefficient. The rejects were found to contain up to 50% cellulose, which is very susceptible to enzymatic hydrolysis to glucose. Knot rejects were hydrolyzed at 20% consistency in a laboratory peg mixer with cellulase enzyme. The thick slurry was liquefied within the first hour of mixing and resulted in a glucose concentration of over 100 g/L after 24 hours of reaction. This solution was fermented by yeast to give an ethanol concentration of over 5%. The laboratory results were confirmed at pilot scale with a mortar mixer (high consistency) or stirred tank reactor (medium consistency) at the 400 L and 6000 L scales, respectively. It was found that washing the knots with ammonia resulted in increased glucose conversion. Enzyme costs could be lowered by separating the enzyme from the hydrolyzed sugars by membrane ultrafiltration and recycling the enzyme to the subsequent batch of substrate. The combination of high-consistency hydrolysis and enzyme recycling minimizes capital investment, energy requirements, and enzyme costs, which are significant factors in the overall economic viability of cellulose conversion to ethanol. PDF Abdel-Kader, A. H., and Darweesh, H. H. (2010). "Setting and hardening of agro/cement composites," BioRes. 5(1), 43-54. In this study, the use of bagasse fiber (BF) and unbleached bagasse pulp (BP) in a cement matrix, as a raw material, to produce lightweight construction materials is reported. The bagasse was used as partial replacement of cement at different levels: 0% (control cement), 1%, 2% 3%, and 4% by weight. The average size of bagasse fibers was less than 2 mm. Although a reduction in the physical and mechanical strength was observed, the incorporation of either fiber or pulp increased the water of consistency and setting time. A composite containing 4% of bagasse fibers can be used for lightweight concrete. FT-IR spectra showed that the BF or BP adversely affect the rate of calcium silicate hydrate (CSH) formation by decreasing its promotion. PDF Afzal, M. T., Bedane, A. H., Sokhansanj, S., and Mahmood, W. (2010). "Storage of comminuted and uncomminuted forest biomass and its effect on fuel quality," BioRes. 5(1), 55-69. White birch was stored in the form of bundles, wood chips, and loose slash for a period of one year to examine the changes in biomass fuel properties. The samples were collected at regular quarterly intervals to measure moisture content, CNS content, ash content, and calorific value. Data loggers were also placed into the stored woody biomass to measure the temperature change inside the piles. After the first quarter of the storage period and continuing into the next three months of storage, the moisture content showed the most significant change. The moisture content of the biomass bundles increased from 29 % to above 80 % (db). The moisture content of the pile of wood chips covered with a tarp decreased from 51% to 26% and showed a continuous decline in moisture content to the end of storage period to an average range of 16.5% (db). However, the moisture content of uncovered wood chip pile was observed to continuously increase throughout the storage period, resulting in more than double in magnitude from 59% to 160% (db). The dry matter loss was higher in wood chip piles (8~27%) than in bundles (~3%). Among the other properties, there was slightly higher loss of calorific value in wood chips (~1.6%) as compared to bundles (~0.7%) at the end of one year. PDF Sahin Kol, H., Ozbay, G., Köse, L., and Kurt, S. (2010). "Effects of some impregnation chemicals on combusion characteristics of laminated veneer lumber (LVL) produced with oak and poplar veneers," BioRes. 5(1), 70-80. The objective of this research was to investigate the effects of impregnation chemicals on the combustion properties of 3-ply laminated veneer lumber (LVL) made of Oak (Quercus petraea subsp. İberica) and Poplar (Populus tremula L.). For this purpose, oak wood was used as the outer ply and poplar used for the core ply in LVL. Borax (BX), boric acid (BA), borax+boric acid (BX+BA), and di-ammonium phosphate (DAP) were used as impregnation chemicals, and urea formaldehyde (UF), phenol formaldehyde (PF), and melamine-urea-formaldehyde (MUF) adhesives as bonding agent were used to produce LVLs. The vacuum – pressure method was used for the impregnation process. The combustion test was performed according to the procedure defined in the ASTM–E 69 standards, and during the test the mass reduction, temperature, and released gas (CO, O2) were determined for each 30 seconds. As a result, di-ammonium phosphate was found to be the most successful fire retardant chemical in LVL with MUF adhesive. LVL produced from a combination of oak and poplar veneers with MUF adhesive and impregnated with DAP can be recommended to be used as a fire resistant building material where required. PDF Soni, S. K., and Soni, R. (2010). "Regulation of cellulase synthesis in Chaetomium erraticum,"BioRes. 5(1), 81-98. Chaetomium erraticum was capable of producing all the three components of a cellulase enzyme system including exoglucanase, endoglucanases, and b-glucosidase extracellularly. However, the cultivation conditions and the medium composition markedly affected the ability of microorganism to synthesize various enzymes. Exoglucanase was highest under static conditions, while endoglucanase and b-glucosidase were maximized under shake conditions. Among the various defined substrates, CMC proved to be the best inducer for exoglucanase under static conditions and b-glucosidase under shake conditions. MCC induced maximum endoglucanase under shake conditions. The biosynthesis of all three components of cellulases was repressed with different concentrations of glucose, puromycin, actinomycin, and actidione, while the supplementation of exogenous cyclic-AMP was fully capable of releasing the catabolite repression for production of all three components. PDF Xie, J., Luo, S., Feng, L., Xu, N., Wang, Y., Xu, W., and Fu, S. (2010). "Production of Trametes gallica lignocellulases for wheat straw degradation," BioRes. 5(1), 99-107. Trametes gallica (T. gallica) is a high producer of lignin-degrading enzymes including laccases, lignin peroxidases (LiPs), manganese-dependent peroxidases (MnPs), and hemicellulases (Hcels). The enzyme activities could peak at an early stage of fermentation. The activities of laccases and LiPs were high in high-nitrogen, low–carbon, and high inorganic salt media, while the activities of MnPs, and Hcels were the high in low-nitrogen, high–carbon, and high inorganic salt medium. It was found that T. gallica caused 34.4% mass losses after 20 days, 46.7% after 30 days, and 70.1% after 60 days, and at the same time T. gallica was able to degrade lignin at an early stage of solid fermentation. Based on these results, T. gallica may be a strain candidate for biopulping in the paper industry. PDF Phanphanich, M., and Mani, S. (2010). "Drying characteristics of pine forest residues," BioRes. 5(1), 108-120. The thin layer drying of pine forest residues consisting of bark, needles, leaves, and chips was experimentally conducted at air temperatures of 40, 50, 60, 70, and 80oC. Physical and chemical properties of fractionated forest residues were determined to evaluate its fuel properties. The experimental data obtained from thin layer drying study were fitted with Lewis, Page, and Henderson and Pabis equations to evaluate the drying behavior of the forest residues. Among the three drying models, the Henderson and Pabis model fitted well with the experimental drying data at the tested temperatures (40, 50, 60, 70, 80oC), achieving R2 values of0.992, 0.994, 0.997, 0.989, and 0.983, respectively. The drying constant k for the forest residues was increased with increase in drying air temperature and was correlated in the form of a second order regression equation. The thin layer drying data developed from this study will be useful for designing low temperature dryers for forest residues. PDF Patel, S. V., Venditti, R. A., and Pawlak, J. J. (2010). "Dimensional changes of starch microcellular foam during the exchange of water with ethanol and subsequent drying," BioRes. 5(1), 121-134. Starch microcellular foams (SMCF) containing pores in the micron size range may be prepared by pore-preserving drying processes, developing highly porous, high specific surface area materials useful for applications such as opacifying pigments or as adsorbent materials. The objective of this research was to understand how the exchange of water with ethanol, used as a pore preserving step, affected the dimensional properties of the starch material during and after processing. SMCF were prepared from molded aquagels of cooked corn starch that were subjected to ethanol exchanges with different time intervals (6, 12, or 48 hrs) and number of exchanges (1, 2, or 3) and then air dried. To study the transformation of water-swollen starch into precipitated starch foam in ethanol, the volume of the starch material was measured in the wet state after each exchange and after final air drying. As water is replaced by ethanol, the starch material contracts, with the greatest contraction during the first ethanol exchange. The amount of contraction during air drying decreased with decreased starch water content just before air drying, presumably due to less pore collapse of the stiffer cell walls on drying. Interestingly, the minimum density of 0.37 g/cc SMCF was for the 12 hour exchange time, not the longest exchange time. Evidence of a skin-core morphology included SEM images as well as dimensional instability data on dried samples. The results indicate that SMCF of low density with fewer tendencies to deform during drying does not necessarily require extremely long exchange times. PDF Zhang, M., Chen, H.-P, Gao, Y., He, R.-X., Yang, H.-P., Wang, X.-H., and Zhang, S. H. (2010). "Experimental study on bio-oil pyrolysis/gasification," BioRes.5(1), 135-146. This study aims to understand the mechanism of bio-oil gasification and the influence of operating parameters on the properties of the gas products. Firstly, the pyrolysis/gasification of bio-oil was performed using a thermogravimetric analyzer (TGA). The evaporation of gas products from bio-oil were measured on-line with coupled Fourier Transform Infrared Spectroscopy (FTIR). The main gas products were CO, CO2, CH4, H2O, and light hydrocarbons, etc. Organics mainly evolved out at lower temperature (100-200°C), while the cracking of heavy hydrocarbon components took place at higher temperature (>200°C). Simultaneously, the gasification behavior of bio-oil was investigated in a fixed bed gasification reactor under different temperature and residence time. The gas product evolving was checked using micro-gas chromatography. It was observed that the yield of CO and H2 increased with increasing gasification temperature above 600°C, and the maximum value was obtained at 800°C. Prolonging the residence time was not favorable for the upgrading of syngas quality. PDF Lu, X., Zhang, Y., Yu, Y., and Ji, J. (2010). "Deacidification and esterification of waste cooking oil: Comparison of the coupled process with stand-alone catalytic esterification and extraction processes," BioRes. 5(1), 147-158 The free fatty acids in waste oil with high acid value were removed and transformed into fatty acid methyl esters by the extraction-reaction coupled process. The de-acidification efficiency and esterification conversion in the extraction-reaction coupled process were studied and compared with those in the stand-alone extraction process and the esterification process, respectively. Compared with cross-current batch extraction, the de-acidification efficiency of the extraction-reaction coupled process was equivalent to that of seven equilibrium stages in the conditions of the oil/methanol mass ratio of 1:1 at 60 oC. Compared with the esterification process, the esterification conversion of the coupled process was 90.3%, which is much larger than 46% in the esterification process at the reaction time of 32 minutes. Based on these findings, it is suggested that the extraction-reaction coupled process is a very effective and promising method for biodiesel production from oils having high acid value. PDF Yadav, R. D., Chaudhry, S., and Dhiman, S. S. (2010). "Biopulping and its potential to reduce effluent loads from bleaching of hardwood kraft pulp," BioRes. 5(1), 159-171. Mixed hardwood chips were treated with lignin-degrading fungi to study the effect of fungal pretreatment on bleaching characteristics of kraft pulp. Pretreated wood chips were subjected to reduced active alkali doses in comparison to untreated chips. Comparable results were obtained for pretreated chips with reduced alkali dose as was obtained with higher dose of alkali in case of untreated chips. Fungal treatment made the process more energy-efficient, and 4.8% less chlorine was consumed in comparison to the control process. Pretreatment with Ceriporiopsis subvermispora was responsible for reduction of 4.7% in lignin contents, 14.3% permanganate number, and overall reduction of 15.5 kg/T of Cl2 consumption. The pollution load in terms of COD and BOD at the CD stage was reduced by 32.6% and 41.5% respectively, whereas 12% reduction in AOX compounds was observed in effluent of pretreated pulp. PDF Valto, P., Knuutinen, J., Alén, R., Ranatalankila, M., Lehmonen, J., Grönroos, A., and Houni, J. (2010). "Analysis of resin and fatty acids enriched in papermaking process waters," BioRes. 5(1), 172-186. The applicability of a special pilot-scale installation (Short Circulation Device) was studied for demonstrating the enrichment of selected resin and fatty acids in process waters when increasing water reuse during the manufacture of paper. The traditional gas chromatography with flame ionization detection (GC-FID), turbidity, and online sample enrichment (solid phase extraction, SPE) for atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) measurements were used for the analysis of the resin and fatty acids. The data from all the measurements with unbleached thermomechanical pulp (TMP) process waters were in a good agreement, and correlation coefficients (R2) > 0.9 were obtained in each case. Rapid information about the levels of wood extractives in papermaking process waters is of great importance, and it offers a suitable way to predict oncoming pitch problems. It was concluded that the routine control of the extractives level in papermaking process waters is possible by all these methods. PDF
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