NC State
  • Editorialpp 4770-4772Song, S., Wang, P., and Zhang, M. (2018). "Filler bondability factor as a tool for maximizing the potential of mineral additives in paper production," BioRes. 13(3), 4770-4772.AbstractPDF

    Increasing filler content in paper while maintaining paper strength is a continuous need in the paper industry. The bonds between cellulosic fibers and fillers are essential to increase filler level in paper. Besides tensile strength, which traditionally has been used to investigate different fillers on fiber bonding, a new factor, i.e. a filler bondability factor, can be applied in evaluating the mitigation effect of filler addition on fiber bonding. This factor shows its effectiveness in optimizing the key parameters for filler modification and the choice of filler, and it helps to maximize the use of filler in the paper industry.

  • Editorialpp 4773-4775Chen, Z., Yue, X., He, Z., and Zhang, L. (2018). "China’s new regulations on waste paper importing and their impacts on global waste paper recycling and the papermaking industry in China," BioRes. 13(3), 4773-4775.AbstractPDF

    China is the largest waste paper importing market in the world. Due to more and more demands and awareness of environment/ safety issues, in recent years the Chinese government has implemented a number of new regulations on waste paper importing, for example, prohibiting importing of unsorted waste paper and lowering the foreign (non-paper) content in the imported waste paper from 1.5% to 0.5%. Small-scale (less than 50,000 tons per year capacity) paper mills are not eligible for importing waste paper. These new regulations have had profound impacts on the global waste paper recycling practice and the papermaking industry in China. At the same time, these new regulations bring up new challenges to the global waste paper recycling practices, such as increased labor costs and decreased recycling efficiency.

  • Researchpp 4776-4794Gaff, M., Hýsek, Š., Sikora, A., and Babiak, M. (2018). "Newly developed boards made from crushed rapeseed stalk and their bendability properties," BioRes. 13(3), 4776-4794.AbstractPDF

    The bendability of a material can be classified as both a positive and negative characteristic. The classification depends on the intended use of the given material. In the case of materials intended for bending (solid wood), this property is positive; whereas in the case of building materials this property may have a negative effect on the stability and durability of the finished structure. Depending on the use of the material, different characteristics of bendability can be used to describe it. The important characteristics include the force and deflection at the limit of proportionality and at the modulus of rupture. Because the bendability also depends on the material thickness, this characteristic is most often expressed as the ratio of the material thickness to the smallest achievable bent radius. Therefore, an analysis of the minimum curve radius and coefficient of bendability was performed. The bending characteristics were measured for composite materials, which were made of crushed rapeseed stalk and bonded with powder polyester adhesive. The stalks were subjected to different modifications (R, H2O, and NaOH). The results of this work indicated that rapeseed is a prospective raw material for the production of composite materials with specific properties.

  • Researchpp 4795-4806Tian, S., Zhao, R., and Zhao, J. (2018). "Production of bioethanol from sweet potato tubers with different storage times," BioRes. 13(3), 4795-4806.AbstractPDF

    To meet the demands for screening sweet potato tubers for bioethanol production, 12 genotypes of sweet potato tubers were collected from Henan, Shandong, Anhui, and Jiangsu Provinces, China. Based on the optimized determination method of the percent dry content, the nutritional composition and fermentation properties were studied. There were differences in the compositions and their correlations among the sweet potato varieties. The results showed that the starch content was weakly correlated with other ingredients, while the percent dry content and fermentable sugars contents had a close correlation with starch content. The percent dry content significantly and positively correlated with the flour and fermentable sugars contents. The percent dry content and starch contents had a significantly positive correlation, with a correlation coefficient that reached 0.96.

  • Researchpp 4807-4819Woźniak, M., Gałązka, A., Grządziel, J., and Frąc, M. (2018). "Microbial diversity of Paulownia spp. leaves – A new source of green manure," BioRes. 13(3), 4807-4819.AbstractPDF

    This study aimed to analyze the structural and functional diversity of microorganisms inhabiting Paulownia spp. leaves. Next Generation Sequencing (NGS) and Biolog EcoPlates were used to determine microbial diversity. The leaves of Paulownia spp. were taken from two different plantations. Among all the samples, P112_1 was the most abundantly colonized by plant growth promoting bacteria. Overall, the microbial community of the P. elongata × P. fortunei (PB) sample characterized the lowest metabolic activity with the utilization of the carbon sources. All communities used carbohydrates abundantly, whereas amines and amides were used the least. The differences observed may have been due to a variety of factors from composition of the chemicals in the leaf, to the soil type, to the climatic conditions.

  • Reviewpp to be addedHubbe, M. A., Henniges, U., Potthast, A., Ahn, K., and Smith, R. (2018). "Nonaqueous solution deacidification treatments to prolong the storage life of acidic books: A review of mechanistic and process aspects," BioRes. 13(3), Page numbers to be added.AbstractPDF

    According to published studies, certain nonaqueous solution-based treatments can be highly effective for prolonging the useful lives of bound volumes, within which the paper had been formed under acidic papermaking conditions. Such treatments, which typically use reactive alkoxide-based organometallic compounds dissolved in low-surface-tension liquids, have been shown to decrease the tendency of the paper to become brittle during long storage or during accelerated aging. This article reviews published evidence concerning the underlying mechanisms of such treatments. Evidence suggests that dissolved alkoxides and related carbonated alkoxide-based compounds are able to react directly with acidic species within acidic paper during treatment of books. Such reactions help explain the demonstrated effectiveness of nonaqueous solution-based deacidification treatments.

  • Researchpp 4820-4831Sartori, C., Mota, G., Miranda, I., Mori, F., and Pereira, H. (2018). "Tannin extraction and characterization of polar extracts from the barks of two Eucalyptus urophylla hybrids," BioRes. 13(3), 4820-4831.AbstractPDF

    Barks from two commercial clones of Eucalyptus urophylla hybrids used by the charcoal industry in Brazil were analyzed, with their polar extracts characterized. Also, tannins were extracted with water and sodium sulfite. The mean bark chemical composition showed 2.6% ash, 16% extractives (89% of which were polar extractives), 1.2% suberin, 18.9% lignin, and 61.4% polysaccharides composed mainly of glucans (glucose 48.3% of bark) and xylans (xylose plus arabinose 10.1% of bark). The polar extracts included high mean contents of total phenolics (380.9 mg GAE / g extract), flavonoids (178.4 mg CE / g extract), and tannins (67.7 mg CE / g extract). The mean antioxidant activity of the extracts was low (53.6 mg Trolox / g of bark extract). The extracts had Stiasny indices of 20% with water and 45% with sodium sulfite solution. The FTIR spectra showed condensed tannin bands characteristic of C=C, C-C, and O-H bonds. The barks of E. urophylla hybrids are a potential source of polar extractives that may represent an important valorization.

  • Researchpp 4832-4840Supriyanto, G., Rukman, N. K., Nisa, A. K., Jannatin, M., Piere, B., Abdullah, A., Fahmi, M. Z., and Kusuma, H. S. (2018). "Graphene oxide from Indonesian biomass: Synthesis and characterization," BioRes. 13(3), 4832-4840.AbstractPDF

    Graphene oxide (GO) was synthesized from graphite and also produced from waste materials, such as coconut shell, rice husk, and bagasse. The GO obtained from pure graphite was compared with graphite made from Indonesian biomass (coconut shell, rice husk, and bagasse) that had its silica content removed. The characterization of GO was with X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy. The XRD images showed the formation of the GO and graphite from various angles and revealed that the chemical reaction had an important role in the formation of the GO particles. This was confirmed by the FTIR and Raman spectra, where the presence of various oxygen functional groups was identified. The FTIR spectra showed that the GO had some functionals oxygen groups within its structure.

  • Researchpp 4841-4855Peşman, E., and Parlak, M. (2018). "Recycling of colored office paper. Part II: Post-bleaching with formamidine sulfinic acid and hydrogen peroxide," BioRes. 13(3), 4841-4855.AbstractPDF

    In this study, the optimization of formamidine sulfinic acid (FAS) and hydrogen peroxide (P) bleaching stages of pre-bleached blue, red, yellow, green, and mixed colored office papers was investigated. The FAS was performed as a strong color stripping reagent on blue and green colored samples. However, due to reduced amine compounds FAS was not found to be effective on the red colored samples. In contrast, effective results were obtained with hydrogen peroxide on the red and yellow colored samples. These results showed that the two reagents must be used together in a sequence. Therefore, in this study, FASP and PFAS bleaching sequences were also investigated and the optical properties (absorbance (k/s) spectra, CIE L*a*b* color values, and ISO brightness) of these sequences were compared. The color differences (CIE ΔE) of FASP and PFAS bleaching sequences of the mixed colored samples were calculated as 18.2% and 16.1%, respectively. The FASP bleaching sequence was determined to be more effective than the PFAS sequence for the bleaching of all samples. As a result, this study showed that FAS, a strong reducing agent, and hydrogen peroxide, an effective oxidative decolorizer, can be used together to obtain white writing papers from waste direct dye colored office papers.

  • Researchpp 4856-4869Hodoušek, M., Böhm, M., Součková, A., and Hýsek, Š. (2018). "Effect of moisture content on the air permeability of oriented strand boards," BioRes. 13(3), 4856-4869.AbstractPDF

    Changes in the air permeability and density profiles of 12-mm-thick oriented strand board (OSB) specimens were evaluated in relation to changes in their moisture content. The test methodology consisted of the simulation of real conditions that may occur during construction. Using a water bath, the OSB moisture content was increased from 10% to 17%, and the consequent changes in the air permeability and vertical density profile (VDP) were analyzed. The air permeability and VDP were then reanalyzed after acclimatization of the OSB to a balanced moisture content at 60% relative air humidity and 11.4 °C. After wetting the boards with an initial moisture content of 10% for 2 h and naturally re-drying them in laboratory conditions, an average increase of 11.7% in air permeability was observed. The increase in air permeability was 5.6% with a pressure difference of 50 Pa. After redrying, the boards showed a 1.1% lower average density and 14.5% lower maximum density in the surface layers. From the results, it followed that even the short-term effects of water and the related increase in moisture content of the OSB had a negative impact on the air permeability and VDP.

  • Researchpp 4870-4883Mohammad, B. T., Al-Shannag, M., Alnaief, M., Singh, L., Singsaas, E., and Alkasrawi, M. (2018). "Production of multiple biofuels from whole camelina material: A renewable energy crop," BioRes. 13(3), 4870-4883.AbstractPDF

    Camelina sativa is a cool-season oil seed crop that has been proven to produce various biofuels. The present study investigated the technical possibilities of using whole camelina biomass as a model feedstock in a biorefinery. This investigation examined the possibilities of using camelina seeds as a source of oil for biodiesel, sugars for ethanol, and meal for one-portfolio products. The camelina harvest residues (straw) can serve as the main source for green sugars. This study found that the energy input for the whole biorefinery process was 25.1 MJ/L ethanol, while the energy output was 54.3 MJ/L ethanol. The net energy ratio of 2.16 MJ/L ethanol was found to be competitive with other energy crops. The process was environmentally friendly, and it reduced greenhouse gas emissions by 40% if the produced biodiesel replaced petroleum diesel. The seed meals and glycerin were found to be a good source of revenue as high value-added products and can provide an additional revenue of $1/kg of produced oil.

  • Researchpp 4884-4896Li, Y., Wang, X., Song, H., Shao, J., Ma, H., and Chen, H. (2018). "Phenols production from online catalytic conversion of corn stalk pyrolysis vapors using char in-situ," BioRes. 13(3), 4884-4896.AbstractPDF

    Char in-situ (char[is]) obtained from corn stalk pyrolysis was evaluated as a catalyst to upgrade corn stalk pyrolysis vapors. A catalyst evaluation device was introduced to conduct the experiments. The effects of reaction temperature and char[is] dose on catalytic performances in biomass pyrolysis were evaluated. The results showed that the char in-situ had a remarkable effect on the pyrolysis products. Under the action of char[is], the primary compounds of pyrolysis vapors were catalytically converted into phenolic products, such as phenol and 4-ethyl-phenol, while the acetic acid content was evidently reduced. The product selectivity was not dependent on the polar functional groups on the char[is]’s surface according to the Fourier transform infrared (FTIR) results, but might have been dependent on the mesoporous structure and the basicity sites of the charis as well as the metallic species in the char[is]. A possible reaction mechanism for phenols production and acetic acid inhibition was proposed.

  • Researchpp 4897-4915Xiao, K., Zhou, W., Geng, M., Feng, W., Wang, Y., Xiao, N., Zhu, D., Zhu, F., and Liu, G. (2018). "Comparative evaluation of enzymatic hydrolysis potential of Eichhornia crassipes and sugarcane bagasse for fermentable sugar production," BioRes. 13(3), 4897-4915.AbstractPDF

    In the production of biofuel from biomass, the enzymatic hydrolysis potential (EHP) of feedstock plays a critical role in determining the process’s saccharification efficiency (SE) and economic feasibility. In this study, the artificial biomass of Eichhornia crassipes (EC) and sugarcane bagasse (SB), as well as the actual biomass of EC and SB pretreated by four different chemical methods, were subjected to enzymatic hydrolysis. A binary linear-regression equation (BLE), y=β1χ1+β2χ2, was derived to illustrate the relationship between the sugar yield (y) and the proportions of key components (cellulose and hemicellulose) (χ1, χ2) with different compositional contributions (β1 and β2) to y. The EC cellulose was found to make a greater contribution than SB cellulose, resulting in higher SE of EC. Furthermore, the SE of pretreated actual biomasses exhibited similar trends and positive correlation with the predictions, indicating good applicability of the BLE model and highlighting the superior EHP of EC. This study advances the understanding of roles played by key biomass components in the enzymatic hydrolysis process, which informs decisions on the EHP of different types of biomass, facilitating the screening of suitable biomass for enhanced SE and cost-effective biomass-to-energy conversion.

  • Researchpp 4916-4930Gao, X., Yu, Y., Jiang, Z., Liu, Y., Zhang, W., and Zhang, L. (2018). "Direct dissolution and spinning of the agricultural waste of corn straw pulp," BioRes. 13(3), 4916-4930.AbstractPDF

    Agricultural waste of corn straw pulp was successfully prepared into fibers using a tetrabutylammonium acetate (TBAA) and dimethyl sulfoxide (DMSO) solvent system via a dry-jet wet spinning process at 35 °C. The dissolving process of cellulose in TBAA/DMSO was observed through a polarization microscope, and the rheological behavior of the cellulose/ TBAA/DMSO solution was also studied. The crystalline and microstructure of the regenerated cellulose fibers prepared from corn straw were investigated by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). In addition, the morphology was characterized with a scanning electron microscope (SEM). The thermal stability of corn straw pulp and the regenerated cellulose was also explored. Due to the presence of residual lignin, a longer time was needed for the complete dissolution of corn straw compared with pure wood pulp. In addition, the degree of polymerization and the elongation-at-break of the regenerated fiber had a small amount of attenuation. Despite the deficiencies, a good spinnability of corn straw cellulose solution could still be achieved. Fibers with a round and compact structure as well as a smooth surface were obtained.

  • Researchpp 4931-4945Ashraf, M. A., Arshad, M. I., Rahman, S., and Khan, A. (2018). "Characterization of moderately thermostable α-amylase-producing Bacillus licheniformis from decaying potatoes and sweet potatoes," BioRes. 13(3), 4931-4945.AbstractPDF

    Bacillus licheniformis is an endospore-forming bacterium that is commonly present in soil. The aim of the present study was to isolate and characterize local strains of α-amylase producing B. licheniformis. Soil samples were collected from the decaying surfaces of potatoes and sweet potatoes. The samples were identified by Gram staining, spore staining, and motility testing under aerobic conditions. Twenty-three isolates were found to be from the Bacillus genus and six of those (26%) were found to be B. licheniformis. Two representative samples were run on API 20E and API 50 CH biochemical kits, and 16S rDNA polymerase chain reaction. The isolates were confirmed to be B. licheniformis by the API-web program and molecular detection. Partially purified α-amylase was characterized to determine the effect of the incubation period, temperature tolerance, and pH stability. The activity peaked at 740 mU/mL after 42 h of culturing. The relative activity reached a maximum at 55 °C and a pH of 8.0. The decaying surfaces of potatoes and sweet potatoes are promising sources of α-amylase-producing strains of B. licheniformis that can tolerate both a high temperature and drastic pH level.

  • Researchpp 4946-4963Geng, W., Venditti, R. A., Pawlak, J. J., and Chang, H. (2018). "Effect of delignification on hemicellulose extraction from switchgrass, poplar, and pine and its effect on enzymatic convertibility of cellulose-rich residues," BioRes. 13(3), 4946-4963.AbstractPDF

    Hemicellulose is an abundant and underutilized carbohydrate polymer in plants. The objective of this study was to understand the effect of delignification on hemicellulose extraction efficiency with different types of lignocellulosic biomass. In the case of pine, with a prior sodium chlorite or peracetic acid delignification, more than 50% of the original hemicellulose in the biomass could be extracted using a 10% sodium hydroxide solution; without delignification, only 3.4% of hemicellulose could be extracted from pine. In contrast, without prior delignification, acceptable hemicellulose extraction efficiencies (55.5% and 50.7%, respectively) were achieved from switchgrass and poplar. In addition, the effect of hemicellulose extraction processes on the enzymatic convertibility of the cellulose-rich residues after extraction was determined. The cellulose-rich residues from switchgrass after hemicellulose alkali extraction showed high glucose recovery with enzyme hydrolysis with or without prior delignification. For pine and poplar, high glucose recovery with enzyme hydrolysis of the cellulose-rich residues only occurred if the sample had a delignification step prior to hemicellulose extraction. This information on commercially available biomass feedstocks is useful for those considering isolating hemicellulose within a biorefinery concept.

  • Researchpp 4964-4972Lopes, D. J. V., Benigno Paes, J., and dos Santos Bobadilha, G. (2018). "Resistance of Eucalyptus and Corymbia treated woods against three fungal species," BioRes. 13(3), 4964-4972.AbstractPDF

    The genera Eucalyptus and Corymbia are widely used in Brazil. Although they present remarkable applicability, they manifest substantial end-splitting and surface checks, which allows wood decay organisms to penetrate the wood. Thereby, the resistance of Eucalyptus grandis x Eucalyptus urophylla (EU) and Corymbia citriodora (CT) treated with chromated copper arsenate type-C (CCA-C) against fungi decay was evaluated. Seventy-two fence posts were assessed; for each species, there were 18 posts treated with CCA-C and 18 non-treated posts. The posts were 2.20 m long and classified into three classes of diameter. The 2% active ingredient was used with a vacuum-pressure cycle. On each fence, disks measuring 2.0 cm thick were cut at the outcrop zone. Two sets of depths were analyzed: the edge at 0 cm to 1.5 cm as well as the inner part at 1.5 cm to 3.0 cm. The samples were subjected to Postia placenta, Gloeophyllum trabeum, and Trametes versicolor attack. The treatment was effective against all fungi, but for CT, the diameter range of 8 cm to 12 cm was optimal. The treated wood from EU samples reached the lowest weight loss for all fungi. Heartwood-sapwood ratio played a major role. By comparing the non-treated woods, EU yielded the highest mass loss.

  • Researchpp 4973-4985Chen, K., Liu, D., Chen, X., and Fan, Z. (2018). "Kinetic analysis of Fe(II)-promoted ethanol preparation from cornstalks," BioRes. 13(3), 4973-4985.AbstractPDF

    This paper presents a kinetic study of fuel grade ethanol production by simultaneous saccharification and fermentation from Fe(II)-catalyzed cornstalks. The study observed the optimal conditions of ethanol production as: inoculation proportion (ratio of Pachysolen tannophilus to Saccharomyces cerevisiae) 2:1, fermentation temperature 32 °C, inoculation quantity 20%, addition amount of Fe2+ 4 mg/g (substrate), and cellulase dosage 30 U/g (substrate). An ethanol yield of 0.335 mg/g was obtained from cornstalks pretreated using liquefaction under optimum conditions. A 30.4% increase in the yield was observed when compared with the control group without the addition of Fe2+. The relationship between ethanol yield and fermentation time could be described through a Langmuir isotherm model. The findings of this study will help researchers better understand and describe the complex characteristics of ethanol production from cornstalks with Fe2+ promoter, which will be very useful in improving production yields.

  • Researchpp 4986-4997Bátori, V., Jabbari, M., Srivastava, R. K., Åkesson, D., Lennartsson, P. R., Zamani, A., and Taherzadeh, M. J. (2018). "Synthesis and characterization of maleic anhydride-grafted orange waste for potential use in biocomposites," BioRes. 13(3), 4986-4997.AbstractPDF

    The purpose of the study was to develop a less hydrophilic, and therefore more useful, material from orange waste produced in large quantities by the food industry. A new derivative of industrial orange waste was synthesized via esterification with maleic anhydride. The reaction was confirmed via Fourier transform infrared spectroscopy (FTIR), and the degree of substitution of the hydroxyl groups was 0.39 ± 0.01, as determined by a back-titration method. A major change in physical structure was confirmed by scanning electron microscopy (SEM). The flake-like structure of orange waste changed to a sponge-like structure after the reaction, which involved an increased volume and a reduced density by approximately 40%. The sponge-like structure was represented as an agglomeration of particles with a low specific surface area of 2.18 m2/g and a mean pore diameter of 10.7 nm. Interestingly, the grafted orange waste seemed to become more hydrophobic, which was confirmed by a contact angle test; however, the material absorbed more water vapor. Thermogravimetric analysis (TGA) confirmed a thermally more uniform, though, less heat-resistant material. This work suggests a possible way of utilizing orange waste via synthesizing a renewable material with possible applications as a filler in biocomposites.

  • Researchpp 4998-5012Che Hamzah, N. H., Yahya, A., Che Man, H., and Samsu Baharuddin, A. (2018). "Effect of pretreatments on compost production from shredded oil palm empty fruit bunch with palm oil mill effluent anaerobic sludge and chicken manure," BioRes. 13(3), 4998-5012.AbstractPDF

    Rapid co-composting of lignocellulosic oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) is a cost-effective and sustainable way to eliminate biomass residues. In this study, suitable pre-treatments and co-substrates for an accelerated composting treatment process were investigated. A steam pre-treatment was performed prior to composting. The composting mixtures were placed in plastic drums under a roofed area. They were regularly turned for aeration and measured for temperature, oxygen, moisture content, bulk density, carbon to nitrogen (C/N) ratio, and fiber tensile strength. C/N ratio is the main parameter measured as a maturity indicator for the compost. The compost temperature was above 60 °C during the thermophilic phase after the steam pre-treatment, based on the heat produced by the microbes. Steam-treated OPEFB and untreated OPEFB co-composted with chicken manure achieved the same maximum temperature of 62 °C and C/N ratios of 8.76 and 9.58, respectively. Steam pretreatment did not have significant effect when the treated OPEFB was co-composted with POME anaerobic sludge due to insufficient steam pressure at 40 psi and 140 °C. Steam-treated OPEFB and untreated OPEFB co-composted with POME anaerobic sludge achieved 54 °C and 60 °C, respectively, while the C/N ratios were 12.41 and 10.14, respectively.


  • Researchpp 5013-5031Asadollahzadeh, M., Ghasemian, A., Saraeian, A., Resalati, H., and Taherzadeh, M. J. (2018). "Production of fungal biomass protein by filamentous fungi cultivation on liquid waste streams from pulping process," BioRes. 13(3), 5013-5031.AbstractPDF

    The aim of this study was to convert the spent liquors obtained from acidic sulfite and neutral sulfite semi-chemical (NSSC) pulping processes into protein-rich fungal biomass. Three filamentous fungi, Aspergillus oryzae, Mucor indicus, and Rhizopus oryzae, were cultivated on the diluted spent liquors in an airlift bioreactor with airflow of 0.85 vvm at 35 °C and pH 5.5. Maximum values of 10.17 g, 6.14 g, and 5.47 g of biomass per liter of spent liquor were achieved in the cultivation of A. oryzae, M. indicus, and R. oryzae on the spent sulfite liquor (SSL) diluted to 60%, respectively, while A. oryzae cultivation on the spent NSSC liquor (SNL) diluted to 50% resulted in the production of 3.27 g biomass per liter SNL. The fungal biomasses contained 407 g to 477 g of protein, 31 g to 114 g of fat, 56 g to 89 g of ash, and 297 g to 384 g of alkali-insoluble material (AIM) per kg of dry biomass. The amino acids, fatty acids, and mineral elements composition of the fungal biomasses corresponded to the composition of commercial protein sources especially soybean meal. Among the fungi examined, A. oryzae showed better performance to produce protein-rich fungal biomass during cultivation in the spent liquors.

  • Researchpp 5032-5041Nurminen, I., Saharinen, E., and Sirviö, J. (2018). "New technology for producing fibrillar fines directly from wood," BioRes. 13(3), 5032-5041.AbstractPDF

    A method for producing lignocellulosic fibrillar fines directly from moist wood through a grinding process was evaluated. The method is based on a conventional stone wood grinding process with a novel grinding stone surface structure. The grinding stone (wheel) with a surface profile serrated in the axial direction of the wheel, forces fibres to break down into fibrils instead of detaching as fibres from the wood matrix. The arrangement mimics the inclined feeding of a log against a grinding stone and is completed without any related technical difficulties. Typically over a 90% conversion rate to fines (passing the Standard Mesh 200 wire) were achieved. The characteristics of the fines were influenced by the details of the surface structures, the velocity of the grinding stones, the feeding rate of the woods, and the specific energy consumption. This method enables novel means to adjusting the structure and properties of paper and paperboard products, as well as those of novel fibre and fibre-composite products.

  • Researchpp 5042-5051Skulcova, A., Russ, A., Jablonsky, M., and Sima, J. (2018). "The pH behavior of seventeen deep eutectic solvents," BioRes. 13(3), 5042-5051.AbstractPDF

    Deep eutectic solvents (DESs) are a unique category of green solvents that have gained attention in biomass processing due to their distinctive properties not offered by traditional solvents. The pH behavior of 17 selected DESs along with their temperature dependence on pH were evaluated in this study. For all investigated DESs, a temperature increase caused a decrease in pH value.

  • Researchpp 5052-5064Bailon-Salas, A. M., Ordaz-Díaz, L. A., Valle-Cervantes, S., López-Miranda, J., Urtiz-Estrada, N., Páez-Lerma, J. B., and Rojas-Contreras, J. A. (2018). "Characterization of culturable bacteria from pulp and paper industry wastewater, with the potential for degradation of cellulose, starch, and lipids," BioRes. 13(3), 5052-5064.AbstractPDF

    The search for microbial enzymatic activities applied to wastewater treatment is an important task in environmental biotechnology. Microbial enzymes have been previously explored in hostile habitats. They are increasingly important in extreme habitats; biological wastewater from the pulp and paper mill industry can harbor microorganisms with valuable enzymatic capabilities that can improve the efficiency for the same process of depuration. This study was performed to characterize and evaluate cellulolytic, amylolytic, and lipolytic activities of bacteria isolated from a pulp and paper effluent. The enzymatic activities were evaluated by the formation of a clear halo around the colonies in defined substrate media. By the use of a sequence analysis of 16S rDNA libraries, isolates were identified. The 16S rDNA libraries belong to the Bacillus subtilis, B. megaterium, B. licheniformis, B. pumilus, B. thuringiensis, B. cereus, Chryseobacterium daecheongense, and Microbacterium sediminis (an alkali-tolerant bacteria which has only been isolated from deep-sea sediment). B. cereus was the best strain for cellulose and lipase activities; moreover, C. daecheongense was best for amylase activity. The present study shows that the aerated lagoons from the pulp and paper industry are a promising source of bacterial with different enzyme activities. This data is relevant for industrial applications.

  • Researchpp 5065-5079Hýsek, Š., Podlena, M., Böhm, M., Bartsch, H., and Wenderdel, C. (2018). "Effect of cold plasma surface pre-treatment of wheat straw particles on straw board properties," BioRes. 13(3), 5065-5079.AbstractPDF

    Effects of the plasma treatment were evaluated for particles from winter wheat stalks relative to the properties of particleboards manufactured from such treated particles. Using urea-formaldehyde adhesive, boards with a nominal density of 540 kg/m3 and a thickness of 6 mm were manufactured. Two degrees of plasma treatment were selected: cold plasma applied at atmospheric pressure by jet system, with a generator output voltage of 26.9 V and a current of 6.9 A; and in the second treatment, a maximum voltage of 28.6 V was used with a current of 8.7 A. The physical properties (equilibrium moisture content and thickness swelling depending on relative humidity) and mechanical properties (bending strength and tensile strength perpendicular to the plane of the board) were determined. The results showed that the plasma pre-treatment of particles had a statistically significant effect on the resulting composite properties. The mechanical properties of the boards increased with both plasma treatments, but the physical properties changed negatively. Boards manufactured from particles treated with a higher degree of plasma treatment resulted in significantly higher equilibrium moisture contents and thickness swelling than the reference boards.

  • Researchpp 5080-5110Saari, J., Kuparinen, K., Sermyagina, E., Vakkilainen, E., Kaikko, J., and Sergeev, V. (2018). "Effect of integration method and carbonization temperature on the performance of an integrated hydrothermal carbonization and CHP plant," BioRes. 13(3), 5080-5110.AbstractPDF

    Wood-fired small- and medium-scale combined heat and power (CHP) plants are a proven technology for producing domestic, carbon-neutral heat and power. Hydrothermal carbonization (HTC) is a promising conversion technology for producing an improved, more versatile wood fuel. By integrating the HTC and CHP processes, the HTC process can be notably simplified. This study compares six different integration schemes to non-integrated plants. The overall energy conversion efficiencies were similar in all six schemes, but there were differences in power output and in plant complexity, and thus likely differences in investment cost and operability. The most promising cases were evaluated at varying HTC temperatures. This comparison showed that temperatures over 220 °C became problematic for the simpler heat recovery schemes, which resulted in poor efficiencies.

  • Researchpp 5111-5123Kłos, R., Fabisiak, B., and Ng, H., K. T. (2018). "Comparative reliability analysis of selected joints for case furniture," BioRes. 13(3), 5111-5123.AbstractPDF

    Specific reliability parameters are used to determine the durability and safety of a furniture structure. An experimental study was conducted to determine the probability of failure free time and compare the reliability and hazard rates of selected joints used in case furniture. The investigations were performed on samples of joints with a connector of the screw, dowel, or eccentric type. Altogether, 600 samples were tested. The reliability tests were conducted on a specially designed laboratory stand. The reliability characteristics of the individual joints were used to designate the most reliable type of joint. The hazard rate of the dowel joint was about 8 times that of the confirmat screw joint. In the case of the eccentric joint, the hazard rate was as much as 57 times higher than it was for the screw joint. The test method presented here for determining the reliability of joints aid in the selection of a connector type during case furniture design.

  • Researchpp 5124-5138Köse Demirel, G., Temiz, A., Jebrane, M., Terziev, N., and Gezer, E. (2018). "Micro-distribution, water absorption, and dimensional stability of wood treated with epoxidized plant oils," BioRes. 13(3), 5124-5138.AbstractPDF

    Samples of Scotch pine sapwood were treated with epoxidized linseed and soybean oils via an empty cell process to improve the hydrophobic properties of wood. Boric acid was included to introduce fungicidal properties into the oils. Two retention levels (80 to 140 kg/m3 and 170 to 270 kg/m3) were targeted for oil treatments. Both an empty cell method and emulsion techniques were used to combine epoxidized oils and boric acid in a one-step treatment. Iodine number changes, Fourier transform infrared spectroscopy (FTIR), water absorption (WA), anti-swelling efficiency (ASE), and scanning electronic microscopy (SEM) analyses were used to characterize the wood after treatment. High iodine number changes that indicated a reduction the amount of unsaturated double bonds were determined. The FTIR analysis of epoxidized oils revealed a peak at 820 cm-1, which indicated that epoxide moieties (C-O-C) were present. All of the oil treatments resulted in statistically significant lower water absorptions than the control sample. The lowest water absorption values were obtained from wood treated with epoxidized oils. The highest ASE result (70%) was observed on samples treated with epoxidized soybean oil at low retention (108 kg/m3). It was also determined that most of the latewood tracheids were filled with oils when compared to the earlywood tracheids.

  • Researchpp 5139-5152Li, M., Fang, G., Cai, Z., Zhou, J., and Fan, H. (2018). "Improvement to the solubility and reactivity of purified bamboo fibers using a combined chemi-mechanical process," BioRes. 13(3), 5139-5152.AbstractPDF

    Bamboo fibers exhibit poor solubility and reactivity because of the aggregational structure of cellulose macro-molecules in fiber cell walls. It has been shown that more free hydroxyl groups on cellulose molecules can be exposed via fibrillation of the fiber walls during a PFI beating process. The changes in fiber characteristics, such as the fibrillation degree, water retention value (WRV), and crystallinity, were analyzed. The results showed that the fiber fibrillation increased from 0.781% to 1.072%, and the WRV increased from 112.8% to 213.6% during the beating process, indicating that a fibrillation effect was present in the bamboo fiber walls that corresponded to an incremental change in the degree of mechanical pretreatment. The saturated solubility value of the treated fibers in an alkali/urea solvent system at low temperature increased from 0.22 wt.% to 2.69 wt.% with an incremental change in the degree of mechanical pretreatment. After high-revolution PFI beating, the cellulose crystallinity index of the samples decreased from 66.4% to 50.0%, but the intrinsic viscosity changed only slightly. The oxidation degree of the cellulose in the treated samples increased from 0.85 mol/AGU to 1.03 mol/AGU, which suggested that the reagent accessibility and chemical reaction performance of the bamboo fibers were both improved.

  • Researchpp 5153-5163Huang, Y., Li, F., Meng, J., and Chen, W. (2018). "Lignin content of agro-forestry biomass negatively affects the resultant biochar pH," BioRes. 13(3), 5153-5163.AbstractPDF

    The biomass type is one of the most important factors that affects biochar properties, but the relationship between the major constituents of different biomasses and the properties of the derived biochars, especially the pH, is still unclear. In this study, the cellulose, hemicellulose, lignin, and ash contents of 30 representative agro-forestry biomasses and the pH, surface acid functional groups, and carbonates of 150 resultant biochars prepared with different heat treatment temperatures (HTTs) were examined. The results showed that the lignin content of the biomass had a strong negative correlation with the biochar pH (r = −0.428, P < 0.01). When the HTT was 300 °C, a high lignin content in the biomass was found to have increased the acid functional groups in the biochar, which resulted in a relatively low pH. When the HTT was greater than or equal to 400 °C, the high lignin content in the biomass negatively correlated to the carbonates, which led to a low biochar pH. It was concluded that the lignin content of agro-forestry biomass affects the biochar pH negatively, and the acid functional groups and carbonates have different effects at different HTTs.

  • Researchpp 5164-5178Hu, Z., Musikavanhu, B., Li, J., Li, J., and He, Z. (2018). "ZnCl2 pretreatment of bamboo chips to produce chemi-thermomechanical pulp: Saving refining energy and improving pulp properties," BioRes. 13(3), 5164-5178.AbstractPDF

    The pretreatment of biomass materials is critical for improvement of the overall production process and product quality. In this work, a dilute zinc chloride (ZnCl2) solution was used to pretreat bamboo chips, followed by defiberization (mechanical pulping). Compared to the results from the traditional chemi-thermomechanical pulping process, the results from this study showed that the refining energy consumption of the modified process was lowered 27%, and the tensile and burst index of the resultant pulp increased 22% and 82%, respectively. The morphological changes on the fiber surface, functional groups, and crystallinity of resultant pulps due to the ZnCl2 treatment were also analyzed.

  • Researchpp 5179-5192Podlena, M., Hýsek, Š., Procházka, J., Böhm, M., and Bomba, J. (2018). "Axial loading of different single-pin dowels and effect on withdrawal strength," BioRes. 13(3), 5179-5192.AbstractPDF

    Withdrawal strengths of commercially available hardwood dowels were examined in this work. Multi-grooved dowels with a straight surface pattern and with pre-glued polyvinyl acetate (PVAc) were tested. Additionally, standard dowels with different single- and multi-grooved surface patterns were also tested, which were not pre-glued. Standard dowels were bonded with two types of PVAc and one type of polyurethane (PUR) adhesive. The influence of the type of dowel, the surface pattern, the dowel diameter, and the type of adhesive used on the dowel joint strength were investigated. Lower average strengths were observed for single-grooved dowels with a spiral pattern (4.9 MPa); failures generally occurred at the first or second thread of the spiral groove. For the pre-glued dowels, there were differences in the observed strengths, which depended upon how the PVAc adhesive was activated. Lower withdrawal strengths were noted for the pre-glued dowels when they were activated by dipping them in water (3.0 MPa) versus adding water directly to the pre-drilled holes (4.7 MPa to 5.4 MPa).

  • Researchpp 5193-5203Chen, Q., Chen, K., Wang, K., Ma, J., Yang, H., and Chen, J. (2018). "The effects of time and temperature in hydrothermal pretreatment on the enzymatic efficiency of wheat straw," BioRes. 13(3), 5193-5203.AbstractPDF

    An attempt to correlate biomass characteristics to its susceptibility to enzymes is often inconclusive via investigation of the variables of hydrothermal pretreatment. Based on an integrated analysis of physicochemical properties, cellulose bioconversion, loss of pentose sugars, formation of inhibitory products, and the cost of energy, the optimal hydrothermal operation for wheat straw (1:20 w/v%) was found. This optimal operation involved cooling the hydrolysates as soon as the temperature reached 180 °C. Finally, a total of 40.7% glucose and 70.3% sugars were recovered during subsequent enzymatic hydrolysis. Although treatment at a noticeably increased severity with a long incubation time could lead to almost 100% conversion of cellulose, the weight losses (mainly sugars) and inhibitors in the process liquid were not well suited for an industrial scale operation.

  • Researchpp 5204-5212Wang, B., Li, Y., Si, H., Chen, H., Zhang, M., and Song, T. (2018). "Analysis of the physical and chemical properties of activated carbons based on hulless barley straw and plain wheat straw obtained by H3PO4 activation," BioRes. 13(3), 5204-5212.AbstractPDF

    High specific surface area activated carbon was prepared by improving the process conditions of phosphoric acid activation and hulless barley straw and plain wheat straw as raw materials. The effects of the activation time on the pore structure and specific surface area of two types of activated carbon were investigated. The results revealed that soaking straws in the high concentrations of H3PO4 for 0.5 h to ensure complete soaking and then removing the straws from H3PO4 solution to activate was beneficial to the infiltration of H3PO4 in the raw material, and there was an increase in the surface area of activated carbon. The largest specific surface area of activated carbon prepared from plain wheat straw and hulless barley straw was 1524 m2/g and 1885 m2/g, respectively. Thermogravimetric analysis and scanning electron microscopy showed that the higher cellulose content, higher hemicellulose content, and smaller fiber morphology in hulless barley straw compared with wheat straw were the main reasons for the more abundant pore structure and higher specific surface area of the activated carbon.

  • Researchpp 5213-5224Zhao, D., Pan, C., Ping, W., and Ge, J. (2018). "Degumming crude enzyme produced by Bacillus cereus HDYM-02 and its application in flax retting," BioRes. 13(3), 5213-5224.AbstractPDF

    A cellulase-free, degumming crude enzyme was produced by Bacillus cereus HDYM-02, using konjaku flour as an inexpensive substrate. After 48 h fermentation, this crude enzyme consisted of pectinase and mannanase, whose maximum activity was 756.7 U/mL and 2967.3 U/mL, respectively. This crude enzyme exhibited considerable stability under the conditions resembling industrial flax retting. After 120 h incubation, more than 50% of the maximum activity of both pectinase and mannanase was retained at pH value 4.0 to 7.0, and at least 70% of the maximum activity was detected at 25 °C to 40 °C. The degumming liquid retted by this crude enzyme contained more galacturonic acid and reducing sugar than those in the degumming liquid retted by commercial pectinase. The application of B. cereus HDYM-02 crude enzyme resulted in higher weight loss of flax stems, better properties, higher productivities, and smoother surfaces of flax fibres. This study showed promise for the use of B. cereus HDYM-02 crude enzyme for flax retting in the textile industry.

  • Researchpp 5225-5240Kuittinen, S., Yang, M., Kaipiainen, E., Villa, A., Keinänen, M., Vepsäläinen, J., and Pappinen, A. (2018). "Acetone–butanol–ethanol fermentation of non-detoxified dilute acid extracted hemicellulosic hydrolysate from the short-rotation coppice Salix schwerinii E. Wolf," BioRes. 13(3), 5225-5240.AbstractPDF

    The dilute acid-catalyzed extraction of hemicellulosic monosaccharides from the short-rotation coppice Salix schwerinii E. Wolf was optimized to find a balance between the yields of fermentable monosaccharides and sugar degradation products for non-detoxified acetone-butanol-ethanol fermentation with Clostridium acetobutylicum. At the same time, the cellulosic and lignin fractions were kept as intact as possible for further refining. The highest xylose and glucose yields in the liquid prehydrolysate were 65% and 9.45% of their respective original content at a combined severity of 2.29. Increased concentrations of glucose and sugar degradation products in the liquid prehydrolysates were detected with an increasing pretreatment temperature and combined severity, while the acid-insoluble lignin remained stable. During the fermentation of the non-detoxified liquid prehydrolysate with grain starch as the supplement, 66% of the xylose was utilized, and the butanol and acetone-butanol-ethanol yields were 0.22 g/g and 0.35 g/g monosaccharides, respectively, in the fermentation medium. The results suggested that the hemicellulose in S. schwerinii can be separately extracted as a side stream and utilized for butanol fermentation with starch-based materials without a separate detoxification stage.