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BioResources
  • Researchpp 5791-5808Giacomozzi, D. E., and Joutsimo, O. (2015). "Drying temperature and hornification of industrial never-dried Pinus radiata pulps. 1. Strength, optical, and water holding properties," BioRes. 10(3), 5791-5808.AbstractArticlePDF

    Hornification and changes in properties of bleached Pinus radiata pulps were studied for oven-dried pulps and compared to never-dried pulps. Evaluation of unrefined and PFI-refined pulps showed an increase in strength loss with high drying temperature. The tensile index was reduced by 40 to 55%, the tear index was reduced by 14 to 31%, and the degree of hornification, measured as WRV, increased from 25 to 34% when the drying temperature was increased from 25 °C to 130 °C. The tensile stiffness index, Scott bond, and elongation were reduced, whereas the bulk, opacity, air permeability, and light scattering values increased at high drying temperatures. Neither fiber deformations nor damages were observed to justify such reductions in strength properties. In PFI refining, pulps dried at 130 °C required three times more revolutions than never-dried pulps to develop tensile index until 70 Nm/g. Dried pulps were found to have less capability to hold water into the fibers’ pore structure, as shown by water retention value. Changes in Scott bond, bulk, and water retention value suggested that besides irreversible pore closure and fibril microfibril aggregation, delamination can contribute to the observed strength loss in dried compared to never-dried pulps.

  • Researchpp 5809-5819Choudhary, M., Sharma, P. C., and Garg, N. (2015). "Crop residue degradation by autochthonous fungi isolated from cropping system management scenarios," BioRes. 10(3), 5809-5819.AbstractArticlePDF

    In the rice-wheat system dominated belt of India (Indo-Gangetic plains; IGP), paddy leaves, about 8 to 9 t/ha of loose and anchored residue in the field, are mechanically harvested. Farmers prefer to burn this residue to clear the field for the timely preparation of conventional wheat sowing. In-situ degradation by autochthonous fungi can be a better option for the disposal of unwanted crop residues. Autochthonous fungi isolated from conservation agriculture-based crop management fields were screened and assessed for their residue degradation potential. Nineteen isolates were selected for detailed enzymatic analysis in submerged fermentation, responsible for lignocellulosic residue degradation. Out of these five fungal isolates RPW 1/3 (Aspergillus flavus), RPW 1/6 (Aspergillus terreus), RPW 1/9 (Aspergillus terreus), RPWM 2/2 (Penicillium janthinellum) and RZWM 3/1 (Aspergillus niger) showed higher activities of cellobiase, CMCase, FPase, xylanase, and laccase enzymes in solid state fermentation. Further two isolates RPW 1/3 and 1/6 showed approximately 30% degradation of straw residue after 10 days incubation.

  • Researchpp 5820-5829Song, J., Yuan, Q., Liu, X., Wang, D., Fu, F., and Yang, W. (2015). "Combination of nitrogen plasma modification and waterborne polyurethane treatment of carbon fiber paper used for electric heating of wood floors," BioRes. 10(3), 5820-5829.AbstractArticlePDF

    The aim of this study was to improve the electrical resistivity, mechanical properties, and interfacial properties between the carbon fiber (CF) and cellulose of conductive paper containing 10% CF so as to better meet the demands for electric heating wood floors. With waterborne polyurethane (WPU) treatment and nitrogen plasma modification methods, the interfacial properties between CF and cellulose were improved dramatically. Fourier transform infrared spectrometry (FTIR) revealed that the plasma modification method reduced the C-H contents and introduced numerous polar groups onto the CF surface. Scanning electron microscopy (SEM) showed that the CF modified by WPU and plasma had good adhesion with cellulose. The tensile index, tensile energy absorption index, and burst index of the paper were enhanced because of the plasma and WPU coating. The carbon fiber and WPU method presented good synergistic action with respect to mechanical properties and electrical resistivity, and the lowest electrical resistivity of conductive paper was reduced from 0.68 omega•cm2 to 0.44 omega•cm2.

  • Researchpp 5830-5844Zhang, M., Zhang, D., Feng, Y., Min, D., and Dai, H. (2015). "The optimization of the water footprint and strength properties of handsheets by the extreme vertices mixture design," BioRes. 10(3), 5830-5844.AbstractArticlePDF

    Water footprint (WF) is widely used as a life cycle assessment (LCA) tool to assess the environmental impacts of water usage associated with forestry-based production. The calculations of WF are significantly influenced by the raw materials and the process. Some information is available on WF in the papermaking industry. However, there has been little consideration of the correlation between the WF and the properties of paper. Technically, the WF and the properties of paper are impacted by the raw materials. Generally, the ideal formula of raw materials used to make paper could decrease the WF while maintaining the properties of the paper. In the current study, the extreme vertices mixture design was used to optimize the WF and properties of the handsheet by the raw materials. The new model indicated that the WF of the handsheet was decreased significantly while the properties was maintained through the adjustment of the raw materials.

  • Researchpp 5845-5862Jablonský, M., Dubinyová, L., Varga, S., Vizárová, K., Šima, J., and Katuščák, S. (2015). "Cellulose fibre identification through color vectors of stained fibre," BioRes. 10(3), 5845-5862.AbstractArticlePDF

    Simple, rapid staining analytical methods with visual color assessment are the most used in practice, but they involve problems including subjective error, low accuracy, qualitative results, and the necessity of using many kinds of stains and a great deal of morphology information for correct identification. A method of objective fiber identification using color vectors of a microscan from stained fibre digital photography is described in this report. A model set of cellulose fibres was prepared: groundwood; sulphate pulp; Whatman paper; and rag fibres. The objective micro-colorimetric method, using RGB (red, green, blue) vectors with discriminatory analysis, reduced the number of stains to 1; requires no morphological information; and the discriminatory power (dp,) of this approach is up to 95 to 100% of correctly identified unknown samples with one color vector R or B. A dp value of 100% was achieved when using 2-P or 3-P combinations of R, G, and B.

  • Researchpp 5863-5875Yang, G., Wang, C., Lyu, G., Lucia, L. A., and Chen, J. (2015). "Catalysis of glucose to 5-hydroxymethylfurfural using Sn-beta zeolites and a Brønsted acid in biphasic systems," BioRes. 10(3), 5863-5875.AbstractArticlePDF

    Selective and efficient dehydration of glucose to 5-hydroxymethylfurfural (HMF) has been a widely explored concept recently, especially from the perspective of employing environmentally benign heterogeneous catalysts. However, there has been a relative paucity of data regarding the application of Sn-Beta zeolites, a category of catalysts that are very innocuous, inexpensive, and effective, toward evaluating bio-based conversions. Sn-Beta was shown to possess good Lewis acidity for catalyzing glucose isomerization to fructose in aqueous media at low pH and accelerating dehydration of glucose to HMF in a biphasic system with high yields. Sn-Beta zeolite with NH4F as the mineralizing agent (Sn-Beta-F) was a more effective catalyst for the selective dehydration of glucose to HMF. An optimal HMF yield of 53.0% was obtained over Sn-Beta-F zeolite in an acidic environment (pH 1) after 70 min at 190 °C. The reaction system was also effective for conversion of cellulose to HMF with a yield of 32.2% preliminarily.

  • Researchpp 5876-5889Cellatoğlu, N., and İlkan, M. (2015). "Torrefaction of solid olive mill residue," BioRes. 10(3), 5876-5889.AbstractArticlePDF

    Solid olive mill residue (SOMR), a lignocellulosic material obtained from olive oil extraction, is a potential attractive source of biomass for energy generation. Although SOMR can be directly combusted, a pretreatment can reduce the oxygen and moisture contents of raw SOMR for efficient energy generation. Torrefaction is a promising thermal pretreatment method for improving fuel characteristics of raw SOMR. In this study, torrefaction characteristics of SOMR were investigated at three different torrefaction temperatures and holding times. Ultimate and proximate analysis results of torrefied SOMR were compared with dried SOMR. Results indicate that an increased torrefaction temperature and holding time can lead to a more qualified solid fuel with higher carbon content, increased higher heating value (HHV), and reduced oxygen content. Further, increased HHV and removal of volatiles are indicators of more energy-dense solid fuel obtained from SOMR. Experimental results revealed that moderately severe torrefaction conditions with holding times not exceeding 30 minutes are suitable for torrefaction of SOMR.

  • Researchpp 5890-5905Boakye-Boaten, N. A., Xiu, S., Shahbazi, A., and Fabish, J. (2015). "Liquid hot water pretreatment of Miscanthus x giganteus for the sustainable production of bioethanol," BioRes. 10(3), 5890-5905.AbstractArticlePDF

    The production of ethanol from lignocellulosic biomass provides an alternative to fossil fuels. In this study, liquid hot water (LHW)-pretreated Miscanthus x giganteus (MxG) was used to produce bioethanol through simultaneous saccharification and fermentation (SSF). MxG was pretreated at temperatures between 170 and 200 °C, for 5 to 15 min. The pretreatment was able to remove between 68.3% and 77.0% of the lignin present in the biomass. The highest percentage yields of sugars from pretreated MxG after enzymatic saccharification (32 °C, pH 4.5, 48 h), by a cocktail of two enzymes were 44.0% glucose and 42.0% xylose of theoretical. Ethanol concentrations between 0.780 and 3.715 g/L, and a high ethanol yield of 71.8% of theoretical were obtained using Saccharomyces cerevisiae (ATCC 24858) for fermentation. A comparison of scanning electron micrographs of the pretreated biomass showed morphological changes that enhanced the release of glucose and bioethanol yield.

  • Researchpp 5906-5919Su, W., Chen, C., Zhu, Y., Yang, W., and Dai, H. (2015). "Fouling characteristics of dissolved organic matter in papermaking process water on polyethersulfone ultrafiltration membranes," BioRes. 10(3), 5906-5919.AbstractArticlePDF

    In the papermaking industry, closure of process water (whitewater) circuits has been used to reduce fresh water consumption. Membrane separation technology has potential for use in treating process water for recirculation. The purpose of this study was to reveal the fouling characteristics of a polyethersulfone (PES) ultrafiltration membrane caused by dissolved organic matter (DOM) in process water. Ultrafiltration membranes (UF) and DAX ion exchange resins were applied to characterize the molecular weight (MW) and hydrophilicity distribution of DOM. The interactions between various fractions of DOM and a PES ultrafiltration membrane were investigated. The membrane fouling characteristics were elucidated by examining the filtration resistances and linearized Herman’s blocking models. The results demonstrated that the membrane was fouled significantly by much of the MW distribution. The membrane was fouled more significantly by the low MW fraction rather than the high MW fraction. The filtration resistances and the fitted equation of Hermia’s laws indicated that hydrophilic organics were the main foulants. The hydrophilic organics partially block the membrane pores and form intermediate blocking, reducing the effective filtration area, while the hydrophobic organics form a gel layer or cake on the surface of the membrane.

  • Researchpp 5920-5931Anjos, O., García-Gonzalo, E., Santos, A. J. A., Simões, R., Martínez-Torres, J., Pereira, H., and García-Nieto, P. J. (2015). "Using apparent density of paper from hardwood kraft pulps to predict sheet properties, based on unsupervised classification and multivariable regression techniques," BioRes. 10(3), 5920-5931.AbstractArticlePDF

    Paper properties determine the product application potential and depend on the raw material, pulping conditions, and pulp refining. The aim of this study was to construct mathematical models that predict quantitative relations between the paper density and various mechanical and optical properties of the paper. A dataset of properties of paper handsheets produced with pulps of Acacia dealbata, Acacia melanoxylon, and Eucalyptus globulus beaten at 500, 2500, and 4500 revolutions was used. Unsupervised classification techniques were combined to assess the need to perform separated prediction models for each species, and multivariable regression techniques were used to establish such prediction models. It was possible to develop models with a high goodness of fit using paper density as the independent variable (or predictor) for all variables except tear index and zero-span tensile strength, both dry and wet.

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