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Sample records for biobleaching softwood kraft

  1. Producing a True Lignin Depolymerase for Biobleaching Softwood Kraft Pulp

    Energy Technology Data Exchange (ETDEWEB)

    Simo Sarkanen

    2002-02-04

    This project constituted an intensive effort devoted to producing, from the white-rot fungus Tramets Cingulata, a lignin degrading enzyme (lignin depolymerase) that is directly able to biobleach or delignify softwood kraft pulp brownstock. To this end, the solutions in which T. cingulata was grown contained dissolved kraft lignin which fulfilled two functions; it behaved as a lignin deploymerase substrate and it also appeared to act as an inducer of enzyme expression. However, the lignin depolymerase isoenzymes (and other extracellular T. cingulata enzymes) interacted very strongly with both the kraft lignin components and the fungal hypae, so the isolating these proteins from the culture solutions proved to be unexpectedly difficult. Even after extensive experimentation with a variety of protein purification techniques, only one approach appeared to be capable of purifying lignin depolymerases to homogeneity. Unfortunately the procedure was extremely laborious; it involved the iso electric focusing of concentrated buffer-exchanged culture solutions followed by electro-elution of the desired protein bands from the appropriate polyacrylamide gel segments

  2. Biobleaching chemistry of laccase-mediator systems on high-lignin-content kraft pulps

    International Nuclear Information System (INIS)

    Chakar, F.S.; Ragauskas, A.J.

    2004-01-01

    A high-lignin-content softwood kraft pulp was reacted with laccase in the presence of 1-hydroxybenzotriazole (HBT), N-acetyl-N-phenylhydroxylamine (NHA), and violuric acid (VA). The biodelignification response with violuric acid was superior to both 1-hydroxybenzotriazole and N-acetyl-N-phenylhydroxylamine. NMR analysis of residual lignins isolated before and after the biobleaching treatments revealed that the latter material was highly oxidized and that the magnitude of structural changes was most pronounced with the laccase - violuric acid biobleaching system. An increase in the content of carboxylic acid groups and a decrease in methoxyl groups were noted with all three laccase-mediator systems. The oxidation biobleaching pathway is directed primarily towards noncondensed C5 phenolic lignin functional structures for all three laccase-mediated systems. The laccase - violuric acid system was also reactive towards C5-condensed phenolic lignin structures. (author)

  3. REPLACEMENT OF SOFTWOOD KRAFT PULP WITH ECF-BLEACHED BAMBOO KRAFT PULP IN FINE PAPER

    Directory of Open Access Journals (Sweden)

    Guanglei Zhao

    2010-06-01

    Full Text Available Non-wood fibers such as bamboo and wheat straw have been playing important roles in the pulp and paper industry in China. In this study an ECF-bleached bamboo kraft pulp was compared with a bleached softwood kraft pulp (NBSK as the reinforcement pulp in fine paper production. Areas that were examined include the refining of pure fibers, influence of bamboo on dewatering, retention, and sizing. The influence of bamboo kraft pulp as a part of a furnish replacing NBSK was compared as well. Results show that fiber shortening was more prominent with bamboo when refined. This resulted in a higher amount of fines, and addition wet-end chemicals may be required to compensate. Handsheets with bamboo as a reinforcement fiber showed similar mechanical and optical properties to handsheets containing NBSK.

  4. Application of thermoalkalophilic xylanase from Arthrobacter sp. MTCC 5214 in biobleaching of kraft pulp

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, R.; Bhosle, N.B.

    released by enzyme treatment showed a characteristic peak at 280 nm indicating the presence of lignin in the released coloring matter. Enzymatic prebleaching of kraft pulp showed 20 % reduction in kappa number of the pulp without much change in viscosity...

  5. Delignification of softwood kraft pulp by chlorine dioxide in a laboratory bleaching liquor displacement reactor

    International Nuclear Information System (INIS)

    Hamzeh, Y.; Izadyar, S.

    2008-01-01

    The chlorine dioxide delignification efficiency of softwood kraft pulp in the laboratory liquor displacement reactor (fixed bed reactor) was investigated and compared with conventional batch reactor. The comparison of two reactors was made based on the effective efficiency and overall efficiency of chlorine dioxide. Effective efficiency corresponds to the oxidizing capacity of chlorine dioxide which consumed by organic materials. Comparison of two reactors based on the effective efficiency showed that the selectivity of delignification significantly enhanced in the displacement reactor in which the primary reaction products are eliminated from reaction zone by displacing flow. On the other hand, the formation of high amounts of chlorate in the reaction zone of displacement reactor reduces the overall efficiency of chlorine dioxide delignification stage. Thus, in spite of significant decrease in useless secondary reactions, this type of reactor would not be cost effective in the industrial scale

  6. Techno-Economic Analysis of the Optimum Softwood Lignin Content for the Production of Bioethanol in a Repurposed Kraft Mill

    Directory of Open Access Journals (Sweden)

    Shufang Wu

    2014-09-01

    Full Text Available Kraft pulping is one possible pretreatment for softwood to economically produce bioethanol. This work evaluates the techno-economic potential of using the kraft process for producing bioethanol from softwoods in a repurposed or co-located kraft mill. Pretreated loblolly pine was enzymatically hydrolyzed at low enzyme dosages of 5 and 10 FPU/g of substrate. Pretreated residue with 13% lignin content had the highest sugar recovery, 32.7% and 47.7% at 5 and 10 FPU/g, respectively. The pretreated residues were oxygen delignified and refined. In all cases, oxygen delignification improved sugar recovery, while refining was mostly effective for pulps with high lignin content. At 5 FPU/g, the sugar recovery for all kraft pulps was 51 to 53% with oxygen delignification and refining. Increasing the enzyme dosage to 10 FPU/g increased the sugar recovery for these pulps to greater than 60%. Economic analysis for the pulps with different initial lignin content showed that kraft pulps with an initial lignin content of 6.7% with oxygen delignification had an ethanol yield of 285 L/ODt wood and the lowest total production cost of $0.55/L. Pulps with initial lignin content of 18.6% had a total production cost of $0.64/L with an ethanol yield of 264 L/ODt wood.

  7. Application of a novel alkali-tolerant thermostable DyP-type peroxidase from Saccharomonospora viridis DSM 43017 in biobleaching of eucalyptus kraft pulp.

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    Wangning Yu

    Full Text Available Saccharomonospora viridis is a thermophilic actinomycete that may have biotechnological applications because of its dye decolorizing activity, though the enzymatic oxidative system responsible for this activity remains elusive. Bioinformatic analysis revealed a DyP-type peroxidase gene in the genome of S. viridis DSM 43017 with sequence similarity to peroxidase from dye-decolorizing microbes. This gene, svidyp, consists of 1,215 bp encoding a polypeptide of 404 amino acids. The gene encoding SviDyP was cloned, heterologously expressed in Escherichia coli, and then purified. The recombinant protein could efficiently decolorize several triarylmethane dyes, anthraquinonic and azo dyes under neutral to alkaline conditions. The optimum pH and temperature for SviDyP was pH 7.0 and 70°C, respectively. Compared with other DyP-type peroxidases, SviDyP was more active at high temperatures, retaining>63% of its maximum activity at 50-80°C. It also showed broad pH adaptability (>35% activity at pH 4.0-9.0 and alkali-tolerance (>80% activity after incubation at pH 5-10 for 1 h at 37°C, and was highly thermostable (>60% activity after incubation at 70°C for 2 h at pH 7.0. SviDyP had an accelerated action during the biobleaching of eucalyptus kraft pulp, resulting in a 21.8% reduction in kappa number and an increase of 2.98% (ISO in brightness. These favorable properties make SviDyP peroxidase a promising enzyme for use in the pulp and paper industries.

  8. Effect of depth beating on the fiber properties and enzymatic saccharification efficiency of softwood kraft pulp.

    Science.gov (United States)

    Gao, Wenhua; Xiang, Zhouyang; Chen, Kefu; Yang, Rendang; Yang, Fei

    2015-01-01

    Commercial bleached softwood kraft pulp was mechanically fibrillated by a PFI-mill with beating revolution from 5000 to 30,000 r. The extent of fibrillating on the pulp was evaluated by beating degree, fiber morphological properties (fiber length, width, coarseness and curls index), water retention value (WRV) and physical properties of paper made from the pulp. Depth beating process significantly affected the pulp fibrillations as showed by the decreased fiber length and width as well as the SEM analysis, but the effects were limited after beating revolution of 15,000. Depth beating process also improved the total internal pore and inter-fibril surface areas as shown by the increased WRV values. Substrate enzymatic digestibility (SED) of beaten pulp at 5000 revolutions could reach 95% at cellulase loading of 15 FPU/g of glucan. After the enzymatic hydrolysis, the size of the pulp residues was reduced to micro-scale, and a relative uniform size distribution of the residues appeared at 10,000 r beating revolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Alkaline peroxide treatment of ECF bleached softwood kraft pulps: part 2. effect of increased fiber charge on refining, wet-end application, and hornification

    Science.gov (United States)

    Zheng Dang; Thomas Elder; Jeffery S. Hsieh; Arthur J. Ragauskas

    2007-01-01

    The effect of increased fiber charge on refining, cationic starch adsorption, and hornification was examined. Two pulps were investigated: (1) a softwood (SW) kraft pulp (KP) which was bleached elementally chlorine-free (ECF) and sewed as control; and (2) a control pulp treated with alkaline peroxide, which had a higher fiber charge. It was shown that increased fiber...

  10. THE REACTIVITY OF PREHYDROLYZED SOFTWOOD KRAFT PULPS AFTER PROLONGED COOKING FOLLOWED BY CHLORITE DELIGNIFICATION

    OpenAIRE

    Ulf Germgard; Muhammad Asif Javed

    2011-01-01

    In a laboratory study high-quality spruce chips were prehydrolyzed to remove hemicelluloses and then kraft cooked to different kappa numbers by varying the cooking time. Each pulp sample was then chlorite delignified to selectively remove the remaining lignin. The reactivities of the pulp samples before and after chlorite delignification were determined by Fock’s test, which is supposed to measure the pulp’s reactivity in the conventional viscose process. A number of analyses were carried out...

  11. Membrane treatment of alkaline bleaching effluents from elementary chlorine free kraft softwood cellulose production.

    Science.gov (United States)

    Oñate, Elizabeth; Rodríguez, Edgard; Bórquez, Rodrigo; Zaror, Claudio

    2015-01-01

    This paper reports experimental results on the sequential use of ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) to fractionate alkaline extraction bleaching effluents from kraft cellulose production. The aim was to unveil the way key pollutants are distributed when subjected to sequential UF/NF/RO membrane separation processes. Alkaline bleaching effluents were obtained from a local pinewood-based mill, featuring elementary chlorine free bleaching to produce high-brightness cellulose. The experimental system was based on a laboratory-scale membrane system, DSS LabStak® M20 Alfa Laval, using Alfa Laval UF and NF/RO membranes, operated at a constant transmembrane pressure (6 bar for UF membranes and 32 bar for NF/RO membranes), at 25°C. Results show that 78% chemical oxygen demand (COD) and total phenols, 82% adsorbable organic halogens (AOX) and 98% colour were retained by UF membranes which have molecular weight cut-off (MWCO) above 10 kDa. In all, 16% of original COD, total phenols and AOX, and the remaining 2% colour were retained by UF membranes within the 1 to 10 kDa MWCO range. Chloride ions were significantly present in all UF permeates, and RO was required to obtain a high-quality permeate with a view to water reuse. It is concluded that UF/NF/RO membranes offer a feasible option for water and chemicals recovery from alkaline bleaching effluents in kraft pulp production.

  12. Kraft pulping of industrial wood waste

    Science.gov (United States)

    Aziz. Ahmed; Masood. Akhtar; Gary C. Myers; Gary M. Scott

    1998-01-01

    Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for energy and/or landfilled. In this study, kraft pulp from industrial wood waste was evaluated and compared with softwood (loblolly pine, Douglas-fir) and hardwood (aspen) pulp. Pulp bleachability was also evaluated. Compared to loblolly pine...

  13. Biopulping of sugarcane bagasse and decolorization of kraft liquor by the laccase produced by Klebsiella aerogenes NCIM 2098

    Directory of Open Access Journals (Sweden)

    Jha H.

    2013-12-01

    Full Text Available Aims: Laccase, a copper-containing enzyme, oxidizes variety of aromatic compounds. Since laccase is essential for lignin degradation, it can be used for lignin removal in the pulp and paper industry (biopulping. Laccase is also employed as a dechlorinating agent (biobleaching, along with the removal of phenolic and other aromatic pollutants. In the present investigation it was aimed to employ the laccase produced by the bacterium Klebsiella aerogenes along with the bacterium itself in biopulping of sugarcane bagasse and biobleaching of kraft liquor effluent. Methodology and results: A laccase was isolated from the bacterium K. aerogenes, purified to homogeneity and characterized. The enzyme was purified by conventional techniques following salt precipitation, ion exchange chromatography, and affinity chromatography on Con A sepharose. The purified laccase was found to be monomeric glycoprotein with a Mr of 64 kDa when measured by Sephadex G-200 gel chromatography and SDS-PAGE. The Vmax and Km of laccase towards the substrate guaiacol was determined. The optimum pH of the laccase was found to be 5.0. biopulping and biobleaching activities were determined by TAPPI standard methods. Treatment of sugarcane baggase by K. aerogenes also significantly reduced lignin content of the bagasse. Conclusion, significance and impact of study: The bacterium K. aerogenes and a laccase produced by it were used separately for biopulping of sugarcane bagasse and biobleaching of kraft liquor effluent. Treatment with both brought significant reduction in lignin content and kappa number of the pulp. The handsheets prepared from the treated pulp showed improved brightness without affecting the strength properties of paper. The bacterium and the laccase efficiently decolorized the kraft liquor proving to have biobleaching potential.

  14. STUDIES ON HIBISCUS CANNABINUS, HIBISCUS SABDARIFFA, AND CANNABINUS SATIVA PULP TO BE A SUBSTITUTE FOR SOFTWOOD PULP- PART 1: AS-AQ DELIGNIFICATION PROCESS

    OpenAIRE

    Dharm Dutt; J. S. Upadhyaya; C. H. Tyagi

    2010-01-01

    Hibiscus cannabinus, Hibiscus sabdariffa, and Cannabinus sativa, which are renewable non-woody fiber resources having characteristics similar to that of softwood (bast fibers), when used together with hardwood (core fibers), gave higher pulp yield with good mechanical strength properties when using an alkaline sulphite-anthraquinone (AS-AQ) pulping process rather than a conventional kraft pulping process and bleached more readily than kraft and soda pulps with a CEHH bleaching sequence. A com...

  15. Removal of COD and color loads in bleached kraft pulp effluents by bottom ashes from boilers.

    Science.gov (United States)

    Van Tran, A

    2008-07-01

    The effectiveness of the bottom ashes from biomass and coal-fired boilers in removing chemical oxygen demand (COD) and colorloads in effluents of a kraft pulp bleachery plant is investigated. The effluents tested are those of the sulfuric acid treatment (A stage) of a hardwood kraft pulp, and of the first acidic (chlorine or chlorine dioxide) and second alkaline (extraction) stages in the chlorine and elemental chlorine-free (ECF) bleaching lines of hardwood and softwood kraft pulps. The coal-fired boiler's bottom ashes are unable to remove either COD or color load in the bleached kraft pulp effluents. However, the bottom ashes of the biomass boiler are effective in removing COD and color loads of the acidic and alkaline effluents irrespective of the bleaching process or wood species. In particular, these ashes increase the pH of all the effluents examined.

  16. Kraft lignin chain extension chemistry via propargylation, oxidative coupling, and Claisen rearrangement.

    Science.gov (United States)

    Sen, Sanghamitra; Sadeghifar, Hasan; Argyropoulos, Dimitris S

    2013-10-14

    Despite its aromatic and polymeric nature, the heterogeneous, stochastic, and reactive characteristics of softwood kraft lignin seriously limit its potential for thermoplastic applications. Our continuing efforts toward creating thermoplastic lignin polymers are now focused at exploring propargylation derivatization chemistry and its potential as a versatile novel route for the eventual utilization of technical lignins with a significant amount of molecular control. To do this, we initially report the systematic propargylation of softwood kraft lignin. The synthesized derivatives were extensively characterized with thermal methods (DSC, TGA), (1)H, (13)C, and quantitative (31)P NMR and IR spectroscopies. Further on, we explore the versatile nature of the lignin pendant propargyl groups by demonstrating two distinct chain extension chemistries; the solution-based, copper-mediated, oxidative coupling and the thermally induced, solid-state, Claissen rearrangement polymerization chemistries. Overall, we show that it is possible to modulate the reactivity of softwood kraft lignin via a combination of methylation and chain extension providing a rational means for the creation of higher molecular weight polymers with the potential for thermoplastic materials and carbon fibers with the desired control of structure-property relations.

  17. Multivariate Analysis of Hemicelluloses in Bleached Kraft Pulp Using Infrared Spectroscopy.

    Science.gov (United States)

    Chen, Zhiwen; Hu, Thomas Q; Jang, Ho Fan; Grant, Edward

    2016-12-01

    The hemicellulose composition of a pulp significantly affects its chemical and physical properties and thus represents an important process control variable. However, complicated steps of sample preparation make standard methods for the carbohydrate analysis of pulp samples, such as high performance liquid chromatography (HPLC), expensive and time-consuming. In contrast, pulp analysis by attenuated total internal reflection Fourier transform infrared spectroscopy (ATR FT-IR) requires little sample preparation. Here we show that ATR FT-IR with discrete wavelet transform (DWT) and standard normal variate (SNV) spectral preprocessing offers a convenient means for the qualitative and quantitative analysis of hemicelluloses in bleached kraft pulp and alkaline treated kraft pulp. The pulp samples investigated include bleached softwood kraft pulps, bleached hardwood kraft pulps, and their mixtures, as obtained from Canadian industry mills or blended in a lab, and bleached kraft pulp samples treated with 0-6% NaOH solutions. In the principal component analysis (PCA) of these spectra, we find the potential both to differentiate all pulps on the basis of hemicellulose compositions and to distinguish bleached hardwood pulps by species. Partial least squares (PLS) multivariate analysis gives a 0.442 wt% root mean square errors of prediction (RMSEP) for the prediction of xylan content and 0.233 wt% RMSEP for the prediction of mannan content. These data all support the idea that ATR FT-IR has a great potential to rapidly and accurately predict the content of xylan and mannan for bleached kraft pulps (softwood, hardwood, and their mixtures) in industry. However, the prediction of xylan and mannan concentrations presented a difficulty for pulp samples with modified cellulose crystalline structure. © The Author(s) 2016.

  18. Combustion properties of kraft black liquors; Ligniinifraktion vaikutus mustalipeaen poltto-ominaisuuksiin

    Energy Technology Data Exchange (ETDEWEB)

    Alen, R.; Rantanen, K.; Ekman, J.; Malkavaara, P. [Jyvaeskylae Univ. (Finland)

    1996-12-01

    The aim of this investigation was to find relationships between the structure of the dissolved lignin and the combustion properties (pyrolysis time, char burning time, and swelling) of softwood and hardwood kraft black liquors. In this conjunction, pine and birch chips, as well as their two mixtures (the mass ratios of pine chips to birch chips were 80:20 and 60:40), were delignified by conventional kraft pulping. In each cook series, a liquor sample was withdrawn at certain time intervals to obtain liquor samples with different chemical composition. The black liquors obtained were analyzed with respect to the content of lignin and `lignin monomers`, but also the molecular-mass distribution and the mass average molecular mass of lignin were made. In addition, the dissolved lignin was characterized by NMR spectroscopy and elemental analysis. Further data on the chemical structures of lignin in black liquors were obtained by identifying various degradation products formed from this material during oxidative (CuO oxidation) and pyrolytic treatments. Several correlations between the `structural parameters` of the dissolved lignin and the combustion properties of black liquor were found. These correlations were significant especially in the case of pine cook. The results revealed many findings which are, together with the earlier data, useful for a better understanding of the thermochemical behavior of different kraft black liquors during combustion in a recovery furnace. (author)

  19. Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes

    Energy Technology Data Exchange (ETDEWEB)

    Chandrashekhar P. Joshi; Vincent L. Chiang

    2009-01-29

    Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl lignin quantities. Summary: The most important wood property affecting directly the levels of energy, chemical and bleaching requirements for kraft pulp production is lignin. Softwoods contain almost exclusively chemically resistant guaiacyl (G) lignin, whereas hardwoods have more reactive or easily degradable lignins of the guaiacyl (G)-syringyl (S) type. It is also well established that the reactive S lignin component is the key factor that permits much lower effective alkali and temperature, shorter pulping time and less bleaching stages for processing hardwoods than for softwoods. Furthermore, our pulping kinetic study explicitly demonstrated that every increase in one unit of the lignin S/G ratio would roughly double the rate of lignin removal. These are clear evidence that softwoods genetically engineered with S lignin are keys to revolutionizing the energy efficiency and enhancing the environmental performance of this industry. Softwoods and hardwoods share the same genetic mechanisms for the biosynthesis of G lignin. However, in hardwoods, three additional genes branch out from the G-lignin pathway and become specifically engaged in regulating S lignin biosynthesis. In this research, we simultaneously transferred aspen S-specific genes into a model softwood, black spruce, to engineer S lignin.

  20. Structural Change in Southern Softwood Stumpage Markets

    Science.gov (United States)

    Douglas R. Carter

    1998-01-01

    The potential for structural change in southern stumpage market models has impacts on not only our basic understanding of those markets, but also on harvest, inventory and price projections, and related policy. In this paper, we test for structural change in both sawtimber and pulpwood softwood stumpage markets in the U.S. South over the period 1950-1994. Test...

  1. Relative efficiency of sawmill types operating in Uganda's softwood ...

    African Journals Online (AJOL)

    The overall aim of this study was to determine the appropriate saw milling ... the swivel and locally-maoufactu red sawmills operating in softwood plantations to improve their feed A ... technologies, poor maintenance of sawmill machinery, poor ... Production of timber from the softwood plantations ..... by Productive Capacity.

  2. Regional softwood sawmill processing variables as influenced by productive capacity

    Science.gov (United States)

    P. H. Steele; F. G. Wagner; K. E. Skog

    The relationship between annual softwood sawmill production and lumber processing variables was examined using data from Sawmill Improvement Program (SIP) studies of 650 softwood mills. The variables were lumber recovery factor (LRF); headrig and resaw kerf width; total sawing variation, rough green size, and oversizing-undersizing for 4/4 and 8/4 lumber; planer...

  3. 78 FR 31315 - Kraft Pulp Mills NSPS Review

    Science.gov (United States)

    2013-05-23

    ... Kraft Pulp Mills NSPS Review; Proposed Rule #0;#0;Federal Register / Vol. 78 , No. 100 / Thursday, May...-OAR-2012-0640; FRL-9815-9] RIN 2060-AR64 Kraft Pulp Mills NSPS Review AGENCY: Environmental Protection... performance standards for kraft pulp mills. These revised standards include particulate matter emission limits...

  4. Kraft cooking of gamma irradiated wood, (1)

    International Nuclear Information System (INIS)

    Inaba, Masamitsu; Meshitsuka, Gyosuke; Nakano, Junzo

    1979-01-01

    Studies have been made of kraft cooking of gamma irradiated wood. Beech (Fagus crenata Blume) wood meal suspended in aqueous alkaline alcohol was irradiated up to 1.5 KGy (0.15 Mrad) with gamma rays from a Co-60 source in the presence or absence of oxygen. The irradiated wood meals were washed thoroughly with fresh water, air dried and cooked under the ordinary cooking conditions. The results are summarized as follows: (1) Pre-irradiation in aqueous alkali have negligible effect on kraft cooking. (2) In the case of ethanol addition (50 g/l), pre-irradiation in vacuo shows acceleration of delignification and stabilization of carbohydrates during kraft cooking. Cooked yield gain by pre-irradiation was about 1.2% in all over the range of delignification from 80 to 90%. Aqueous ethanol without alkali also shows positive but smaller effect than that with alkali. (3) Propanol, iso-propanol and butanol show positive but smaller effects than ethanol. However, methanol does not show any positive effect. (4) Irradiation in the presence of oxygen does not show any attractive effect on kraft cooking. (author)

  5. Ground beetle populations near a kraft mill

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, R.; Hastings, L.; Mercer, W.R.; Smith, A.

    1973-02-01

    Twenty species of ground beetles (Family Carabidae) and one species of carrion beetle (Family Silphidae) were collected in six stations east of a kraft paper mill in Thunder Bay, Ontario, from May to August, 1971. The beetle population decreased markedly towards the mill. There was no apparent statistical difference in size variation of specimens near the mill and those further away.

  6. VOC Control in Kraft Mills; FINAL

    International Nuclear Information System (INIS)

    Zhu, J.Y.; Chai, X.-S.; Edwards, L.L.; Gu, Y.; Teja, A.S.; Kirkman, A.G.; Pfromm, P.H.; Rezac, M.E.

    2001-01-01

    The formation of volatile organic compounds (VOCs), such as methanol, in kraft mills has been an environmental concern. Methanol is soluble in water and can increase the biochemical oxygen demand. Furthermore, it can also be released into atmosphere at the process temperatures of kraft mill-streams. The Cluster Rule of the EPA now requires the control of the release of methanol in pulp and paper mills. This research program was conducted to develop a computer simulation tool for mills to predict VOC air emissions. To achieve the objective of the research program, much effort was made in the development of analytical techniques for the analysis of VOC and determination of vapor liquid partitioning coefficient of VOCs in kraft mill-streams using headspace gas chromatography. With the developed analytical tool, methanol formation in alkaline pulping was studied in laboratory to provide benchmark data of the amount of methanol formation in pulping in kraft mills and for the validation of VOC formation and vapor-liquid equilibrium submodels. Several millwide air and liquid samplings were conducted using the analytical tools developed to validate the simulation tool. The VOC predictive simulation model was developed based on the basic chemical engineering concepts, i.e., reaction kinetics, vapor liquid equilibrium, combined with computerized mass and energy balances. Four kraft mill case studies (a continuous digester, two brownstock washing lines, and a pre-evaporator system) are presented and compared with mill measurements. These case studies provide valuable, technical information for issues related to MACT I and MACT II compliance, such as condensate collection and Clean-Condensate-Alternatives (CCA)

  7. Emissions from burning of softwood pellets

    International Nuclear Information System (INIS)

    Olsson, Maria; Kjaellstrand, Jennica

    2004-01-01

    Softwood pellets from three different Swedish manufacturers were burnt in laboratory scale to determine compounds emitted. The emissions were sampled on Tenax cartridges and assessed by gas chromatography and mass spectrometry. No large differences in the emissions from pellets from different manufacturers were observed. The major primary semi-volatile compounds released during flaming burning were 2-methoxyphenols from lignin. The methoxyphenols are of interest due to their antioxidant effect, which may counteract health hazards of aromatic hydrocarbons. Glowing combustion released the carcinogenic benzene as the predominant aromatic compound. However, the benzene emissions were lower than from flaming burning. To relate the results from the laboratory burnings to emissions from pellet burners and pellet stoves, chimney emissions were determined for different burning equipments. The pellet burner emitted benzene as the major aromatic compound, whereas the stove and boiler emitted phenolic antioxidants together with benzene. As the demand for pellets increases, different biomass wastes will be considered as raw materials. Ecological aspects and pollution hazards indicate that wood pellets should be used primarily for residential heating, whereas controlled large-scale combustion should be preferred for pellets made of most other types of biomass waste. (Author)

  8. Organosolv Fractionation of Softwood Biomass for Biofuel and Biorefinery Applications

    Directory of Open Access Journals (Sweden)

    Christos Nitsos

    2017-12-01

    Full Text Available Softwoods represent a significant fraction of the available lignocellulosic biomass for conversion into a variety of bio-based products. Its inherent recalcitrance, however, makes its successful utilization an ongoing challenge. In the current work the research efforts for the fractionation and utilization of softwood biomass with the organosolv process are reviewed. A short introduction into the specific challenges of softwood utilization, the development of the biorefinery concept, as well as the initial efforts for the development of organosolv as a pulping method is also provided for better understanding of the related research framework. The effect of organosolv pretreatment at various conditions, in the fractionation efficiency of wood components, enzymatic hydrolysis and bioethanol production yields is then discussed. Specific attention is given in the effect of the pretreated biomass properties such as residual lignin on enzymatic hydrolysis. Finally, the valorization of organosolv lignin via the production of biofuels, chemicals, and materials is also described.

  9. Kraft cooking of gamma irradiated wood, (2)

    International Nuclear Information System (INIS)

    Inaba, Masamitsu; Meshitsuka, Gyosuke; Ishizu, Atsushi; Nakano, Junzo

    1981-01-01

    Pre-irradiation of wood in alkaline aqueous ethanol increases kraft pulp yield by up to 1.2%, as already reported. In order to clarify the mechanism of the pulp yield gain, the behaviors of lignin and carbohydrates during pre-irradiation and cooking were investigated. The results are summarized as follows: 1) γ-Irradiation of guaiacylethane in alkaline aqueous ethanol produced 5-(1-hydroxyethyl)-guaicylethane, which is formed by radical coupling between α-hydroxyethyl radical from ethanol and guaiacylethane radical having an unpaired electron at C-5. 5,5'-Dehydrodiguaiacylethane, which may be a predominant product produced by γ-irradiation in the absence of ethanol, was also detected. 2) The yield of vanillin obtained by nitrobenzene oxidation of MWL decreased with an increase of γ-ray dosage. The presence of ethanol during γ-irradiation lessened the extent of this decrease and also the degradation of cellobiose. 3) Gel filtration of the products obtained by γ-irradiation of MWL and cellobiose in the presence of 14 C-ethanol showed the possible combination between ethanol and MWL or cellobiose. 4) Molecular weight distributions of kraft lignin obtained from pre-irradiated beech chips were compared with those obtained from unirradiated chips. This result shows that γ-irradiation in the presence of ethanol decreases the ability of lignin to condense during kraft cooking. (author)

  10. Softwood Lumber – Some Lessons from the Last Softwood (Lumber IV Dispute

    Directory of Open Access Journals (Sweden)

    Elaine Feldman

    2017-10-01

    Full Text Available The checkered history of softwood lumber disputes between Canada and its southern neighbour stretches back to the 1800s, with five of them occurring since 1982. Two years ago, the settlement obtained in 2006 expired and most Canadian softwood lumber exporters now face a combined countervailing and anti-dumping duty rate from the Americans of around 27 per cent. On the surface, the last dispute, known as Lumber IV, appeared to be a squabble over subsidization and dumping of Canadian softwood lumber exports. However, closer scrutiny revealed that this dispute was really about commercial interests triumphing over policy – the U.S. lumber industry wanted to ensure it kept a certain share of the market at the highest price possible. Complicating attempts to resolve any dispute is the fact that Canada is not a single entity in the lumber business; interest in quota or duties varies across regions as do the countervailing (CVD and anti-dumping (AD rates that the U.S. imposes on particular Canadian producers. These variations thus create almost a divide-and-conquer situation in which one group of producers feels others are getting an advantage. The Canadian industry instead should be standing together as much as possible, creating a united front in any dispute with the U.S. Drafting new policy and resorting to litigation to settle Lumber IV failed because the potential settlement got bogged down by the drawbacks of both of those routes. Policy failed because it quickly became clear that the U.S. was going to act with impunity to determine whether there was a subsidy, regardless of what the trade rules permitted. And litigation created an endless loop in which contradictory rulings were handed back and forth between NAFTA panels and the U.S. International Trade Commission, stalling any resolution. Lumber IV also taught the Canadians that taking their complaints to both NAFTA and the World Trade Organization, which does not order a refunding of wrongly

  11. Yield-increasing additives in kraft pulping: Effect on carbohydrate retention, composition and handsheet properties

    Energy Technology Data Exchange (ETDEWEB)

    Vaaler, David Andre Grimsoeen

    2008-07-01

    kraft fibre was found to be 240 +- 20. There are indications that the glucomannan needs a minimum chain length higher than 100 to be retained, as opposed to xylan. There may be error factors in using the traditional intrinsic viscosity (limiting viscosity number) for the determination of the degree of polymerization for cellulose. However, using intrinsic viscosity and the fraction of hemicellulose and cellulose, a much more accurate estimate of the degree of polymerization of cellulose is found, correlating well with the molecular mass of cellulose found by SEC. Brownstock pulping yield can be estimated using three pulp properties; Kappa number, glucomannan and xylan content of pulp in addition to a contribution for the use of AQ. The main error in the yield determination originates from uncertainties in cellulose yield determination. The model seems to be robust and can be used on several softwood species. The influence of hemicellulose content on handsheet properties is studied. Sheet density is used to evaluate the fibre flexibility. The fibre flexibility is closely related to the average fibre wall thickness, hemicellulose content and drying. The drying of pulps and more thick-walled fibres reduces the fibre flexibility while increased hemicellulose content is favourable for high fibre flexibility. Load-elongation properties like tensile index, tensile stiffness index and elongation at rupture have been evaluated. Pulps with a high hemicellulose content are more easily beaten and this results in higher tensile index for pulps with increased hemicellulose content. The reason is that increased swelling of fibres with higher hemicellulose content increases the straightness of fibres resulting in more easily activated fibre segments in the sheet network. However, the extensibility for sheets made of pulps with increased hemicellulose content is reduced. This indicates that the fibres with increased hemicellulose content have more rigid fibre walls that resist axial

  12. 78 FR 38877 - Kraft Pulp Mills NSPS Review

    Science.gov (United States)

    2013-06-28

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 60 [EPA-HQ-OAR-2012-0640] FRL-9829-3 RIN 2060-AR64 Kraft Pulp Mills NSPS Review AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... comments on the May 23, 2013, proposed rule titled, ``Kraft Pulp Mills NSPS Review'' is being extended by...

  13. Geometric model for softwood transverse thermal conductivity. Part I

    Science.gov (United States)

    Hong-mei Gu; Audrey Zink-Sharp

    2005-01-01

    Thermal conductivity is a very important parameter in determining heat transfer rate and is required for developing of drying models and in industrial operations such as adhesive cure rate. Geometric models for predicting softwood thermal conductivity in the radial and tangential directions were generated in this study based on obervation and measurements of wood...

  14. On-site energy consumption at softwood sawmills in Montana

    Science.gov (United States)

    Dan Loeffler; Nathaniel Anderson; Todd A. Morgan; Colin B. Sorenson

    2016-01-01

    Total on-site energy requirements for wood product manufacturing are generally not well understood or publicly available, particularly at subregional scales, such as the state level. This article uses a mail survey of softwood sawmills in Montana to develop a profile of all on-site energy consumption. Energy use is delineated by fuel type on a production basis...

  15. Softwood sawlog secondary transport travel speed prediction for the ...

    African Journals Online (AJOL)

    The objective of this study was to develop a predictive model for travel speed of softwood sawlog timber transport (STT) vehicles over a range of forest and provincial roads of varying condition for the South African forestry industry. Data was accumulated from both the Eastern Cape/KwaZulu-Natal and Mpumalanga forest ...

  16. Clonal multiplication of guava through softwood cuttings under mist conditions

    International Nuclear Information System (INIS)

    Kareem, A.; Jaskkani, M.J.; Fatima, B.; Sadia, B.

    2012-01-01

    Guava (psidium guajava l.) is a luscious and important tropical fruit crop. the objective of the study was to develop vegetative propagation system to avoid clonal degradation in guava fruit plants. softwood cuttings from five year old gola accession were prepared from the shoot tops of current season growth, measuring 12 cm in length and carrying 2 to 4 nodes. iba and naa (0, 2000, 4000, 6000, 8000 ppm) were selected to treat cuttings for root induction. cuttings were planted under mist conditions by maintaining temperature at 25 degree c and 85% relative humidity for 25 days. maximum survival percentage (92.17%) of plants at transplanting was noted with 4000 ppm concentration followed by 2000 ppm (85.50%). In general iba 4000 ppm concentration performed better as compared to naa for all parameters studied. This study revealed the potential of clonal propagation of guava through softwood cuttings treated with auxins. (author)

  17. Cancer incidence among workers exposed to softwood dust in Lithuania.

    Science.gov (United States)

    Smailyte, Giedre

    2012-06-01

    The aim of this study was to assess cancer incidence in a cohort of woodworkers exposed to softwood dust in a Lithuanian wooden joinery products factory. The study population consisted of 1518 workers (1080 men and 438 women) employed in the factory for at least 1 year between 1947 and 1996 and living in Lithuania on 1 January 1978, when the follow-up for cancer incidence began. The follow-up period for cancer was 1978-2007. Cancer risk was assessed by standardised incidence ratios (SIR) with reference to the national population. Overall cancer incidence was not increased among woodworkers. However, the number of mouth and pharynx cancer cases among male woodworkers was significantly increased compared with expected numbers (SIR 2.19, 95% CI 1.17 to 3.74). A higher risk was found for cancer of the buccal cavity than for pharyngeal cancer (SIRs 2.83 and 1.45, respectively). The SIR for larynx cancer was also elevated (SIR 1.39, 95% CI 0.64 to 2.64) among men, while the number of lung cancer cases was higher than expected only among women (SIR 2.07, 95% CI 00.57 to 5.31). This results of this study support the hypothesis that exposure to softwood dust may increase the risk of oral and pharyngeal cancer. No support was found for an increased risk of other respiratory cancers among workers exposed to softwood dust.

  18. Assessment of reproductive effects in largemouth bass (Micropterus salmoides) exposed to bleached/unbleached kraft mill effluents.

    Science.gov (United States)

    Sepúlveda, M S; Ruessler, D S; Denslow, N D; Holm, S E; Schoeb, T R; Gross, T S

    2001-11-01

    This study evaluated the potential effects of different concentrations of bleached/unbleached kraft mill effluent (B/UKME) on several reproductive endpoints in adult largemouth bass (Micropterus salmoides). The kraft mill studied produces a 50/50 mix of bleached/unbleached market pulp with an estimated release of 36 million gal of effluent/day. Bleaching sequences were C90d10EopHDp and CEHD for softwood (pines) and hardwoods (mainly tupelo, gums, magnolia, and water oaks), respectively. Bass were exposed to different effluent concentrations (0 [controls, exposed to well water], 10, 20, 40, or 80%) for either 28 or 56 days. At the end of each exposure period, fish were euthanized, gonads collected for histological evaluation and determination of gonadosomatic index (GSI), and plasma was analyzed for 17beta-estradiol, 11-ketotestosterone, and vitellogenin (VTG). Largemouth bass exposed to B/UKME responded with changes at the biochemical level (decline in sex steroids in both sexes and VTG in females) that were usually translated into tissue/organ-level responses (declines in GSI in both sexes and in ovarian development in females). Although most of these responses occurred after exposing fish to 40% B/UKME concentrations or greater, some were observed after exposures to 20% B/UKME. These threshold concentrations fall within the 60% average yearly concentration of effluent that exists in the stream near the point of discharge (Rice Creek), but are above the <10% effluent concentration present in the St. Johns River. The chemical(s) responsible for such changes as well as their mode(s) of action remain unknown at this time.

  19. AVALIAÇÃO DOS RESÍDUOS DE UMA SERRARIA PARA A PRODUÇÃO DE CELULOSE KRAFT

    Directory of Open Access Journals (Sweden)

    Lucas Cândido Barbosa

    2014-01-01

    Full Text Available The forest-based industries have low yield and generate large amounts of waste, especially the primary processing industries, such as sawmills. In Brazil, initiatives are being created to combine the use of sawmill residues to pulp production. With this in mind, this study aimed to evaluate the performance of amedium-sized sawmill in the city of Rio Grande, in Rio Grande do Sul state, and to promote physical and chemical analysis of waste wood generated in the sawing process. It was used 20 logs of Pinus elliottii , divided into two diameter classes. The residues, except the sawdust, collected for analysis were disposed in the courtyard of the company in the form of chips. The following physical and chemical properties of the chips were examined: density, extractives content soluble in acetone, acetyl groups, soluble and insoluble lignin on acid (Klason lignin, uronic groups and carbohydrates. Comparing the results of the wood properties to the ones found in literature, it was evaluated the quantity and quality of waste that can be used as feedstock for the production of kraft pulp. As the main results there was a slight increase of sawing yields in the larger diameters logs compared to the smaller diameters. From the physical and chemical analyses, it was obtained the following results: density of 0.402 g / cm ³, cellulose content of 43.67% and 24.37% for hemicellulose, klason lignin of 26.75% and 3,80% for extractives content. As conclusion, the low sawing yield can be associated to the lack of a classification diametric and appropriate diagrams sections, resulting in a greater loss in the form of waste. Regarding the chemical and physical composition of the sawmill residues, the results were within the standards of quality wood used for kraft pulp of softwood material, presenting some advantages over younger woods commonly used in industry.

  20. Pulp and paper production from Spruce wood with kraft and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... optical properties of resultant paper were included to determine the properties of these pulp samples. ... pulping compounds in the kraft method are Na2S and .... Scanning electron microscope (SEM) measurement of pulp.

  1. Sixth Status Report: Testing of Aged Softwood Fiberboard Material for the 9975 Shipping Package

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-31

    Samples have been prepared from several 9975 lower fiberboard subassemblies fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. Some softwood fiberboard properties tend to degrade faster in some environments, while some cane fiberboard properties degrade faster in the two most aggressive environments. As a result, it is premature to assume both materials will age at the same rates, and the preliminary aging models developed for cane fiberboard might not apply to softwood fiberboard. However, it is expected that both cane and softwood fiberboard assemblies will perform satisfactorily in conforming packages stored in a typical KAC storage environment for up to 15 years. Samples from an additional 3 softwood fiberboard assemblies have begun aging during the past year to provide information on the variability of softwood fiberboard behavior. Aging and testing of softwood fiberboard will continue and additional data will be collected to support development of an aging model specific to softwood fiberboard.

  2. Kraft Lignin Depolymerization in an Ionic Liquid without a Catalyst

    Directory of Open Access Journals (Sweden)

    Amadou Diop

    2015-06-01

    Full Text Available In this paper, the depolymerization of lignin was successfully achieved by the thermal treatment of kraft lignin in butyl-1,8-diazabicyclo[5.4.0]undec-7-enium chloride ([DBUC4+][Cl-] without a catalyst. The thermal treatment experiments were performed in an oven at 150, 200, and 250 °C for 1 h. The changes in kraft lignin structure over the course of depolymerization were characterized by gel permeation chromatography (GPC, Fourier transform infrared (FTIR spectroscopy, and 1H / 31P NMR analyses. GPC chromatograms indicated that the retention time of the original kraft lignin had shifted toward higher values after the thermal treatment, which indicated lignin depolymerization. The average molecular weight of the lignin obtained after 1 h reaction time decreased by 23, 70, and 58 wt% for the treatment at 150, 200, and 250 °C, respectively. FTIR spectra indicated the cleavage of β-O-4 bonds of kraft lignin. The 1H NMR spectra showed demethylation of all treated kraft lignins. Moreover, the 31P NMR analysis demonstrated that the demethylation phenomenon of the treated kraft lignin contributed to the formation of catechol groups.

  3. Abundance and reactivity of dibenzodioxocins in softwood lignin.

    Science.gov (United States)

    Argyropoulos, Dimitris S; Jurasek, Lubo; Kristofová, Lívia; Xia, Zhicheng; Sun, Yujun; Palus, Ernest

    2002-02-13

    To define the abundance and comprehend the reactivity of dibenzodioxocins in lignin, model compound studies, specific degradation experiments on milled wood lignin, and molecular modeling calculations have been performed. Quantitative (31)P NMR measurements of the increase of biphenolic hydroxyl groups formed after a series of alkaline degradations in the presence of hydrosulfide anions (kraft conditions) showed the presence of 3.7 dibenzodioxocin rings/100 C9 units in milled wood lignin. The DFRC degradation protocol (Derivatization Followed by Reductive Cleavage) was chosen as an independent means to estimate their abundance. Initial experiments with a dibenzodioxocin model compound, trans-6,7-dihydro-7-(4-hydroxy-3-methoxyphenyl)-4,9-dimethoxy-2,11-dipropyldibenzo[e,g][1,4]dioxocin-6-ylmethanol, showed that it is not cleaved under DFRC conditions, but rather it isomerizes into a cyclic oxepine structure. Steric effects precluded this isomerization from occurring when DFRC was applied to milled wood lignin. Instead, monoacetylated biphenolic moieties were released and quantified by (31)P NMR, at 4.3 dibenzodioxocin rings/100 C9 units. The dibenzodioxocin content in residual lignins isolated from kraft pulps delignified to various degrees showed that during pulp delignification, the initial rate of dibenzodioxocin removal was considerably greater than the cleavage rate of arylglycerol-beta-aryl ether bonds. The activation energy for the degradation of dibenzodioxocins under kraft conditions in milled wood lignin was 96 +/- 9 kJ/mol, similar to that of arylglycerol-beta-aryl ether bond cleavage.

  4. Economic analysis of the Canada-United States softwood lumber dispute : playing the quota game

    NARCIS (Netherlands)

    Kooten, van G.C.

    2002-01-01

    The Canada-U.S. Softwood Lumber Agreement (SLA) was the latest measure to restrict Canadian exports of softwood lumber to the United States. Rather than a countervail duty or export tax, SLA employed a quota that provides a large windfall (quota) rent to Canadian lumber producers in addition to

  5. 19 CFR 12.140 - Entry of softwood lumber products from Canada.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Entry of softwood lumber products from Canada. 12... products from Canada. The requirements set forth in this section are applicable for as long as the Softwood... and Canada, remains in effect. (a) Definitions. The following definitions apply for purposes of this...

  6. Evaluation of wet oxidation pretreatment for enzymatic hydrolysis of softwood

    DEFF Research Database (Denmark)

    Palonen, H.; Thomsen, A.B.; Tenkanen, M.

    2004-01-01

    The wet oxidation pretreatment (water, oxygen, elevated temperature, and pressure) of softwood (Picea abies) was investigated for enhancing enzymatic hydrolysis. The pretreatment was preliminarily optimized. Six different combinations of reaction time, temperature, and pH were applied......, and the compositions of solid and liquid fractions were analyzed. The solid fraction after wet oxidation contained 58-64% cellulose, 2-16% hemicellulose, and 24-30% lignin. The pretreatment series gave information about the roles of lignin and hemicellulose in the enzymatic hydrolysis. The temperature...

  7. Studies of lignin transformation in polyoxometalate (POM) bleaching of kraft pulp

    Science.gov (United States)

    Biljana Bujanovic; Richard S. Reiner; Kolby C. Hirth; Sally A. Ralph; Rajai H. Atalla

    2005-01-01

    In order to elucidate changes occurring in lignin during polyoxometalate delignification of kraft pulp, residual lignins of a series of POM- delignified kraft pulps of decreasing kappa number were isolated and characterized. Oxidative treatment of commercial unbleached kraft pulp was performed using complex POM solutions containing the active [SiVW11O40]anion. For...

  8. EFFECT OF STEAMING ON THE COLOUR CHANGE OF SOFTWOODS

    Directory of Open Access Journals (Sweden)

    Laszlo Tolvaj,

    2012-05-01

    Full Text Available The heat treatment of softwood (i.e. spruce, pine, fir, and larch may result in significant colour changes. During this study Scots pine and spruce samples were steamed and analysed for their altered hue and lightness. Treatments included: 0 to 22 days of steaming time at a temperature range of 70 to 100°C. The outcome included a variety of colours between the initial hues and brownish tint. These new colours are similar to that of aged furniture and indoor wooden structures. Consequently, properly steamed softwood may be used to repair historical artefacts and relic furniture. Besides restoration, steamed stocks are excellent sources for manufacture of periodical furniture, where the aged appearance has aesthetical value. Results however, indicated that steaming at a temperature above 90 ˚C has a bleaching effect, i.e. the coloured chemical components formed by moderate steaming may be removed. Furthermore, we observed a linear correlation between lightness and colour hue at all steaming times and temperatures.

  9. Ole Bjørn Kraft 1893-1980

    DEFF Research Database (Denmark)

    Skov, Christian Houlberg

    2010-01-01

    Ole Bjørn Kraft (1893-1980) var en central konservativ politiker i årene før og efter anden verdenskrig. Han markerede sig som udpræget idépolitiker og opnåede ad flere omgange at blive minister.......Ole Bjørn Kraft (1893-1980) var en central konservativ politiker i årene før og efter anden verdenskrig. Han markerede sig som udpræget idépolitiker og opnåede ad flere omgange at blive minister....

  10. ON THE RECOVERY OF HEMICELLULOSE BEFORE KRAFT PULPING

    Directory of Open Access Journals (Sweden)

    Carlos Vila,

    2012-07-01

    Full Text Available To assess the feasibility of implementing hemicellulose recovery stages in kraft mills, Eucalyptus globulus wood samples were subjected to aqueous treatments with hot, compressed water (autohydrolysis processing to achieve partial dissolution of xylan. Autohydrolyzed solids were subjected to kraft pulping under selected conditions to yield a pulp of low kappa number, and to an optimized TCF bleaching sequence made up of three stages (alkaline oxygen delignification, chelating, and pressurized hydrogen peroxide, with minimized additions of pulping and bleaching chemicals. The final product had a relatively low kappa number (1.4, 641 mL/g ISO intrinsic viscosity, and 86.4% brightness.

  11. Composting of organically amended/treated hardwood and softwood sawdust

    International Nuclear Information System (INIS)

    Takyi-Lartey, Rita

    2015-07-01

    Sawdust is a major waste produced by the wood industry. Adding value to sawdust through composting is one of the surest means by which environmental pollution could be minimized. About 500 kg of softwood and hardwood sawdust were separately mixed with mucuna leaves and kitchen waste in the ratio of 3:1:1 on weight basis and heaped using effluent from abattoir to develop composts. Objectives of the study were to monitor changes in the physico-chemical properties, NH4"+ ‒ N, NO3"‒ ‒ N, C:N ratio, minerals N, K, P, microbial load and toxic elements in the composts during a 12 week period. Germination test was also done to evaluate the stability and maturity of the composts developed. Degradation of softwood sawdust compost (SSC) was better in the mesophilic phase while that of hardwood sawdust compost (HSC) occurred in the thermophilic phase. Thus, significantly higher amount of the organic material in SSC was decomposed during the period as compared to HSC. Also, greater percentage of the nitrogen in the initial material of SSC was converted into plant-available inorganic nitrogen (NH4"+ and NO3"‒) than was achieved in HSC. Hence, most of the mineral nitrogen in HSC that was converted was lost, probably in the thermophilic phase. On the contrary, the amount of organic nitrogen contained in the finished composts of both SSC and HSC were adequately good for application to the soil. Additionally, concentrations of pathogenic microorganisms in SSC and HSC products were within acceptable limits in terms of toxicity on growing plants. The softwood sawdust compost was relatively more stable as compared to HSC under the experimental conditions. Concentrations of heavy metals in both SSC and HSC were also within acceptable limits that would cause no toxicity to plants. Also, moisture contents in both SSC and HSC were within the good range (40 - 60%) required for a good compost. Thus both SSC and HSC produced were of good quality. Further research targeting specific

  12. Biobleaching of wheat straw-rich soda pulp with alkalophilic laccase from gamma-proteobacterium JB: optimization of process parameters using response surface methodology.

    Science.gov (United States)

    Singh, Gursharan; Ahuja, Naveen; Batish, Mona; Capalash, Neena; Sharma, Prince

    2008-11-01

    An alkalophilic laccase from gamma-proteobacterium JB was applied to wheat straw-rich soda pulp to check its bleaching potential by using response surface methodology based on central composite design. The design was employed by selecting laccase units, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) concentration and pH as model factors. The results of second order factorial design experiments showed that all three independent variables had significant effect on brightness and kappa number of laccase-treated pulp. Optimum conditions for biobleaching of pulp with laccase preparation (specific activity, 65 nkat mg(-1) protein) were 20 nkat g(-1) of pulp, 2mM ABTS and pH 8.0 which enhanced brightness by 5.89% and reduced kappa number by 21.1% within 4h of incubation at 55 degrees C, without further alkaline extraction of pulp. Tear index (8%) and burst index (18%) also improved for laccase-treated pulp as compared to control raw pulp. Treatment of chemically (CEH1H2) bleached pulp with laccase showed significant effect on release of chromophores, hydrophobic and reducing compounds. Laccase-prebleaching of raw pulp reduced the use of hypochlorite by 10% to achieve brightness of resultant hand sheets similar to the fully chemically bleached pulp.

  13. Computer model for economic study of unbleached kraft paperboard production

    Science.gov (United States)

    Peter J. Ince

    1984-01-01

    Unbleached kraft paperboard is produced from wood fiber in an industrial papermaking process. A highly specific and detailed model of the process is presented. The model is also presented as a working computer program. A user of the computer program will provide data on physical parameters of the process and on prices of material inputs and outputs. The program is then...

  14. Recyclable zein-coated kraft paper and linerboard

    Science.gov (United States)

    Nicholas Parris; Marguerite Sykes; Leland C. Dickey; Jack L. Wiles; Thomas J. Urbanik; Peter H. Cooke

    2002-01-01

    Recyclability of kraft paper and linerboard coated with commercial zein and paraffin wax or a zein-lipid mixture was evaluated using conventional recycling processes. Zein, an alcohol-soluble protein from corn, exhibits both grease and water vapor barrier properties. Strength properties, grease resistance, and water vapor barrier proper-ties were measured on handsheets...

  15. Measurement of cellulose content, Kraft pulp yield and basic density ...

    African Journals Online (AJOL)

    Previous descriptions of multisite and multispecies near infra-red (NIR) spectroscopic calibrations for predicting cellulose content (CC) and Kraft pulp yield (KPY) in eucalypt woodmeal demonstrated that large, single calibrations provide precise predictions for a wide range of sites and species. These have since been used ...

  16. Gamma ray induced chromophore modification of softwood thermomechanical pulp

    International Nuclear Information System (INIS)

    Robert, S.; Daneault, C.; Viel, C.; Lepine, F.

    1992-01-01

    This study focuses on bleaching a softwood (black spruce, balsam fur) thermomechanical pulp with gamma rays. Gamma rays are known for their enormous penetrating power, along with their ionizing properties. They can generate highly energetic radicals capable of oxidizing lignin chromophores. The authors studied the influence of isopropyl alcohol, sodium borohydride, oxygen, hydrogen peroxide, nitrogen dioxide and water along with gamma ray irradiation of the pulps. The authors measured the optimal dose and dose rate, along with the influence of the radical scavengers like oxygen on the bleaching effect of gamma irradiated pulps. They observe various degrees of bleaching of these pulps. Evidence relates this bleaching to the generation of perhydroxyl anions upon irradiation of water. Also, they were able to pinpoint the influence of the dose rate on the rate of formation and disappearance of these perhydroxyl anions and their influence on bleaching kinetics. Stability toward photoyellowing, and photoyellowing's kinetic of papers from these pulps was also studied

  17. Pyrolysis of Softwood Carbohydrates in a Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Dmitry Yu. Murzin

    2008-09-01

    Full Text Available In the present work pyrolysis of pure pine wood and softwood carbohydrates, namely cellulose and galactoglucomannan (the major hemicellulose in coniferous wood, was conducted in a batch mode operated fluidized bed reactor. Temperature ramping (5°C/min was applied to the heating until a reactor temperature of 460 °C was reached. Thereafter the temperature was kept until the release of non-condensable gases stopped. The different raw materials gave significantly different bio-oils. Levoglucosan was the dominant product in the cellulose pyrolysis oil. Acetic acid was found in the highest concentrations in both the galactoglucomannan and in the pine wood pyrolysis oils. Acetic acid is most likely formed by removal of O-acetyl groups from mannose units present in GGM structure.

  18. Pyrolysis of softwood carbohydrates in a fluidized bed reactor.

    Science.gov (United States)

    Aho, Atte; Kumar, Narendra; Eränen, Kari; Holmbom, Bjarne; Hupa, Mikko; Salmi, Tapio; Murzin, Dmitry Yu

    2008-09-01

    In the present work pyrolysis of pure pine wood and softwood carbohydrates, namely cellulose and galactoglucomannan (the major hemicellulose in coniferous wood), was conducted in a batch mode operated fluidized bed reactor. Temperature ramping (5 degrees C/min) was applied to the heating until a reactor temperature of 460 degrees C was reached. Thereafter the temperature was kept until the release of non-condensable gases stopped. The different raw materials gave significantly different bio-oils. Levoglucosan was the dominant product in the cellulose pyrolysis oil. Acetic acid was found in the highest concentrations in both the galactoglucomannan and in the pine wood pyrolysis oils. Acetic acid is most likely formed by removal of O-acetyl groups from mannose units present in GGM structure.

  19. Humidity Data for 9975 Shipping Packages with Softwood Fiberboard

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-01-12

    The 9975 surveillance program is developing a technical basis to support extending the storage period of 9975 packages in K-Area Complex beyond the currently approved 15 years. A key element of this effort is developing a better understanding of degradation of the fiberboard assembly under storage conditions. This degradation is influenced greatly by the moisture content of the fiberboard, which is not well characterized on an individual package basis. Direct measurements of humidity and fiberboard moisture content have been made on two test packages with softwood fiberboard and varying internal heat levels from 0 up to 19W. Comparable measurements with cane fiberboard have been reported previously. With an internal heat load, a temperature gradient in the fiberboard assembly leads to varying relative humidity in the air around the fiberboard. However, the absolute humidity tends to remain approximately constant throughout the package, especially at lower heat loads.

  20. 76 FR 22751 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order...

    Science.gov (United States)

    2011-04-22

    ... 23, 2011. FOR FURTHER INFORMATION CONTACT: Maureen T. Pello, Marketing Specialist, Research and... procedure, Advertising, Consumer information, Marketing agreements, Softwood lumber, Promotion, Reporting... Vol. 76 Friday, No. 78 April 22, 2011 Part II Department of Agriculture Agricultural Marketing...

  1. 75 FR 61025 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order...

    Science.gov (United States)

    2010-10-01

    ... Information Order; Referendum Procedures AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule..., Washington, DC 20503. FOR FURTHER INFORMATION CONTACT: Maureen T. Pello, Marketing Specialist, Research and... procedure, Advertising, Consumer information, Marketing agreements, Softwood Lumber, Promotion, Reporting...

  2. Mergers and acquisitions : the case of Kraft Foods and Cadbury

    OpenAIRE

    Ribeiro, Sara Isabel de Paula

    2013-01-01

    The aim of this dissertation is to focus on a determinant aspect of Corporate Finance that is Mergers and Acquisitions (M&A). This dissertation not only provides a practical analysis of main issued regarding a process of M&A, but also provides a theoretical framework about M&A. Specifically, this dissertation explores the real case of Kraft Foods - world’s second largest manufacturer and packager food products – and Cadbury - the world’s second largest confectionery firm. ...

  3. Dilute alkali pretreatment of softwood pine: A biorefinery approach.

    Science.gov (United States)

    Safari, Ali; Karimi, Keikhosro; Shafiei, Marzieh

    2017-06-01

    Dilute alkali pretreatment was performed on softwood pine to maximize ethanol and biogas production via a biorefinery approach. Alkali pretreatments were performed with 0-2% w/v NaOH at 100-180°C for 1-5h. The liquid fraction of the pretreated substrates was subjected to anaerobic digestion. The solid fraction of the pretreatment was used for separate enzymatic hydrolysis and fermentation. High ethanol yields of 76.9‒78.0% were achieved by pretreatment with 2% (w/v) NaOH at 180°C. The highest biogas yield of 244mL/g volatile solid (at 25°C, 1bar) was achieved by the pretreatment with 1% (w/v) NaOH at 180°C. The highest gasoline equivalent (sum of ethanol and methane) of 197L per ton of pinewood and the lowest ethanol manufacturing cost of 0.75€/L was obtained after pretreatment with 1% NaOH at 180°C for 5h. The manufacturing cost of ethanol from untreated wood was 4.12€/L. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Internationalisation; KonKraft-rapport 4; Internasjonalisering

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    disintegrate. The obvious strategy to pursuit is to strengthen Norway's position as a dynamic and leading competence center for oil- and gas activities. Recruitment and development of sufficient competencies is generally a major challenge for the oil- and gas trade. Shortage of human capital leads to increased wage pressure which in the long run may weaken profits and competitiveness. In some of the petroleum clusters the companies try to find solutions to counteract the negative effects of the battle for the best brains. Through the project KonKraft INTSOK has unveiled high ambitions concerning increased internationalisation throughout the Norwegian petroleum cluster, except for Northern Norway. Here there is still an opposition against activities in the region, as well as in the Barents sea. INTSOK's intention with the project has been to describe its multitude. Therefore eight very different environments where selected to make a closer study on the development in different regions. The environments represent a variety of sizes, geography and trades. Some of the clusters are new or under establishment, others are already in full operation. Together the eight environments cover a major part of the value chain in the Norwegian offshore sector. The project has clearly demonstrated that cluster development contributes both to internationalisation as well as keeping the companies in Norway. Some main findings: The positive development in the drilling cluster of Southern Norway - the Node cluster - has created strong impact: The cluster ranks among the world's leading on drilling equipment and barely any oil or gas environment has had a similar expansion. The Kongsberg environment is not an offshore cluster, but an overall technology cluster where offshore applications is one of several technology areas. The companies develop and produce a broad range of advanced products and systems. The turnover among the offshore companies amounts to 65% of the total turnover for

  5. 75 FR 16748 - Final Voluntary Product Standard; DOC PS 20-10 “American Softwood Lumber Standard”

    Science.gov (United States)

    2010-04-02

    ...-0146-02] Final Voluntary Product Standard; DOC PS 20-10 ``American Softwood Lumber Standard'' AGENCY... of Standards and Technology (NIST) announces voluntary product standard DOC PS 20-10 ``American Softwood Lumber Standard'' which will supersede DOC PS 20-05. The Standard establishes standard sizes and...

  6. Fractionation of high Kappa number kraft pulps of the South African softwoods and sulfonating of coarse fibre enriched fraction for production of sack paper

    CSIR Research Space (South Africa)

    Johakimu, Jonas K

    2011-03-01

    Full Text Available properties except tear strength: Tensile index (54%), TEA index (104%), Burst index (65%) and sheet density (23%). A tear index decrease (30%) could be attrib- uted to a high proportion of short and fine fibres in the accept stream. The reject stream... gave pulp samples with inferior strength properties with exception of tear strength. This may be due to high proportion of coarse fibres which have limited fibre collapsibility. Poor fibre collapsibility leads to a limited fibre bond- ing ability...

  7. Microwave irradiation of lignocellulosic materials, 4: Enhancement of enzymatic susceptibility of microwave-irradiated softwoods

    International Nuclear Information System (INIS)

    Azuma, J.; Higashino, J.; Isaka, M.; Koshijima, T.

    1985-01-01

    Effect of microwave irradiation on the enzymatic susceptibility of various softwoods was investigated. The pH values of the reaction liquor dropped with increasing temperature to 2.9-3.3 at 230°C, consistent with increase in acidity (0.5-0.85 meq at 230-239° C). Above approximately 180°C, hemicellulose underwent acid-mediated autohydrolysis and became water-soluble yielding a mixture of oligosaccharides and monosaccharides. The composition of water-soluble portion was similar for all wood species tested. The maximum extents of saccharification below 240°C ranged between 36-62% for softwoods, while those for hardwoods were between 88-93%. The present investigation confirmed that microwave pretreatment enhanced the enzymatic susceptibility of various softwoods. However, further attempt should be needed to give higher values equal to those for hardwoods. (author)

  8. Bioethanol production: Pretreatment and enzymatic hydrolysis of softwood

    Energy Technology Data Exchange (ETDEWEB)

    Tengborg, Charlotte

    2000-05-01

    The enzymatic hydrolysis process can be used to produce bioethanol from softwood, which are the dominating raw material in the Northern hemisphere. This thesis deals with the development of the process focusing on the pretreatment and the enzymatic hydrolysis stages. The influence of pretreatment conditions on sugar yield, and the effect of inhibitors on the ethanol yield, were investigated for spruce and pine. The maximum yields of hemicellulose sugars and glucose were obtained under different pretreatment conditions. This indicates that two-stage pretreatment may be preferable. The added catalysts, H{sub 2}SO{sub 4} and SO{sub 2}, resulted in similar total sugar yields about 40 g/100 g dry raw material. However, the fermentability of SO{sub 2}-impregnated material was better. This pretreatment resulted in the formation of inhibitors to the subsequent process steps, e.g. sugar and lignin degradation products. The glucose yield in the enzymatic hydrolysis stage was affected by various parameters such as enzyme loading, temperature, pH, residence time, substrate concentration, and agitation. To decrease the amount of fresh water used and thereby waste water produced, the sugar-rich prehydrolysate from the pretreatment step was included in the enzymatic hydrolysis of the solid fraction, resulting in a reduction in the cellulose conversion of up to 36%. Different prehydrolysate detoxification methods, such as treatment with Ca(OH){sub 2}, laccase, and fermentation using yeast, were investigated. The latter was shown to be very efficient. The amount of fresh water used can be further reduced by recycling various process streams. This was simulated experimentally in a bench-scale process. A reduction in fresh water demand of 50% was obtained without any further negative effects on either hydrolysis or fermentation.

  9. Modelling time-dependent mechanical behaviour of softwood using deformation kinetics

    DEFF Research Database (Denmark)

    Engelund, Emil Tang; Svensson, Staffan

    2010-01-01

    The time-dependent mechanical behaviour (TDMB) of softwood is relevant, e.g., when wood is used as building material where the mechanical properties must be predicted for decades ahead. The established mathematical models should be able to predict the time-dependent behaviour. However, these models...... are not always based on the actual physical processes causing time-dependent behaviour and the physical interpretation of their input parameters is difficult. The present study describes the TDMB of a softwood tissue and its individual tracheids. A model is constructed with a local coordinate system that follows...... macroscopic viscoelasticity, i.e., the time-dependent processes are to a significant degree reversible....

  10. Nitrogen oxide emissions from a kraft recovery furnace

    International Nuclear Information System (INIS)

    Prouty, A.L.; Stuart, R.C.; Caron, A.L.

    1993-01-01

    Nitrogen Oxide (NOx) emissions from a rebuilt kraft recovery furnace slightly exceeded the specified limit of 1.1 lb/ton (0.55 kg/metric ton) of black-liquor solids. Mill trials were undertaken to determine whether NOx emissions could be minimized by modifying furnace operation. NOx emissions increased when secondary air was shifted to tertiary ports. NOx emissions fell when the amounts of primary and total air were decreased, but this increased emissions of other pollutants. After demonstrating that best operation of the furnace could not meet the permit with an emissions limit that matched the furnace's performance at best operation

  11. Kraft Foods, Inc. in India — The Cadbury Acquisition

    OpenAIRE

    V. S. Pai; Ram Subramanian

    2014-01-01

    When the United States-based Kraft Foods, Inc. (KFI) acquired the United Kingdom-based Cadbury plc, KFI got entry into the Indian market. KFI CEO, Irene Rosenfeld had targeted the developing markets as key for the company to achieve a 5% organic growth rate and the strong position of Cadbury India augured well for expanding KFI's presence in that market. However, after nearly a year since the acquisition, KFI was moving slowly in India and appeared content to consolidate Cadbury's market pres...

  12. Revealing the Molecular Structural Transformation of Hardwood and Softwood in Dilute Acid Flowthrough Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Libing; Pu, Yunqiao; Cort, John R.; Ragauskas, Arthur J.; Yang, Bin

    2016-12-05

    To better understand the intrinsic recalcitrance of lignocellulosic biomass, the main hurdle to its efficient deconstruction, the effects of dilute acid flowthrough pretreatment on the dissolution chemistry of hemicellulose, cellulose, and lignin for both hardwood (e.g. poplar wood) and softwood (e.g. lodgepole pine wood) were investigated at temperatures of 200 °C to 270 °C and a flow rate of 25 mL/minute with 0.05% (w/w) H2SO4. Results suggested that the softwood cellulose was more readily to be degraded into monomeric sugars than that of hardwood under same pretreatment conditions. However, while the hardwood lignin was completely removed into hydrolysate, ~30% of the softwood lignin remained as solid residues under identical conditions, which was plausibly caused by vigorous C5-active recondensation reactions (C-C5). Unique molecular structural features that pronounced the specific recalcitrance of hardwood and softwood to dilute acid pretreatment were identified for the first time in this study, providing important insights to establish the effective biomass pretreatment.

  13. 76 FR 22757 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order

    Science.gov (United States)

    2011-04-22

    ... concrete dominate larger residential and nonresidential projects. Brick, concrete, and vinyl are often used... products like cement and vinyl has also helped to reduce demand for softwood lumber. \\12\\ Price data was... votes would have to be confirmed in writing and recorded in Board minutes. The proposed Order would...

  14. Environmental impact of manufacturing softwood lumber in northeastern and north central United States

    Science.gov (United States)

    Richard D. Bergman; Scott A. Bowe

    2010-01-01

    Finding the environmental impact of building materials is becoming increasingly more important because of public environmental awareness. Accurate and precise life-cycle inventory data on wood products are needed to meet this demand. This study examined softwood lumber manufacturing in the northeastern and north central US using life-cycle inventory methods. Material...

  15. Effects of humidity level and IBA dose application on the softwood ...

    African Journals Online (AJOL)

    IBA) doses on softwood top cuttings of two black mulberry (Types 1 and 2) and one white mulberry (Type 3) types were studied. Cuttings were taken from early June (14 Haziran) and applied to the different IBA doses (0, 1000, 2000, 3000 and ...

  16. On-site energy consumption and selected emissions at softwood sawmills in the southwestern United States

    Science.gov (United States)

    Dan Loeffler; Nathaniel Anderson; Todd A. Morgan; Colin B. Sorenson

    2016-01-01

    Presently there is a lack of information describing US southwestern energy consumption and emissions generated from the sawmilling industry. This article uses a mail survey of softwood sawmills in the states of Arizona, Colorado, and New Mexico to develop a profile of on-site energy consumption and selected emissions for the industry. Energy consumption is...

  17. Preparation and Characterization of Cellulose Nanofibers from Two Commercial Hardwood and Softwood Pulps

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Sanadi, Anand R.

    2009-01-01

    The aim of this work was to study the mechanical fibrillation process for the preparation of cellulose nanofibers from two commercial hard- and softwood cellulose pulps. The process consisted of initial refining and subsequent high-pressure homogenization. The progress in fibrillation was studied...

  18. Yield Improvement and Energy Savings Uing Phosphonates as Additives in Kraft pulping

    Energy Technology Data Exchange (ETDEWEB)

    Ulrike W. Tschirner; Timothy Smith

    2007-03-31

    Project Objective: Develop a commercially viable modification to the Kraft process resulting in energy savings, increased yield and improved bleachability. Evaluate the feasibility of this technology across a spectrum of wood species used in North America. Develop detailed fundamental understanding of the mechanism by which phosphonates improve KAPPA number and yield. Evaluate the North American market potential for the use of phosphonates in the Kraft pulping process. Examine determinants of customer perceived value and explore organizational and operational factors influencing attitudes and behaviors. Provide an economic feasibility assessment for the supply chain, both suppliers (chemical supply companies) and buyers (Kraft mills). Provide background to most effectively transfer this new technology to commercial mills.

  19. Physical properties of kraft black liquor. Final report. Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, A.L.

    1983-12-01

    Methods were selected, equipment installed, and procedures developed for determining rheological properties; for determining thermal properties (stability, density, thermal expansion, and heat capacity); for purification and characterization of lignin (glass transition, stability, weight average molecular weight, and number average molecular weight); and for performing chemical analyses (negative inorganic ions, positive inorganic ions, acid organic salts, lignin, and total solids). A strategy for pulping to supply test liquors was developed, and a statistically designed pulping experiment was specified for a Southern softwood species. Arrangements were made for performing initial pulping work in an industrial pilot plant, and a preliminary set of pulping experiments were conducted. Liquors from the preliminary pulping experiments were used to test procedures and to determine reproducibility of the experiment. Literature was also surveyed and preliminary selection of designs for a pilot digester, and for equipment to determine surface tension were made.

  20. Biochemical methane potential of kraft bleaching effluent and codigestion with other in-mill streams

    DEFF Research Database (Denmark)

    Fitamo, Temesgen Mathewos; Dahl, Olli; Master, Emma

    2016-01-01

    and in combination: total bleaching effluent, alkaline bleaching effluent, kraft evaporator condensate, and chemithermomechanical pulping effluent. The total bleaching effluent, consisting of the chlorine dioxide bleaching and alkaline bleaching effluents, exhibited the highest potential for organic matter...

  1. Bioconversion of oxygen-pretreated Kraft lignin to microbial lipid with oleaginous Rhodococcus opacus DSM 1069

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Zhen [Hunan Univ. Changsha (China); Zeng, Guangming [Hunan Univ. Changsha (China); Huang, Fang [Georgia Inst. of Technology, Atlanta, GA (United States); Kosa, Matyas [Georgia Inst. of Technology, Atlanta, GA (United States); Huang, Danlian [Hunan Univ. Changsha (China); Ragauskas, Arthur J. [Georgia Inst. of Technology, Atlanta, GA (United States); Univ. of Tennessee, Knoxville, TN (United States)

    2015-04-09

    Kraft lignin (KL) from black liquor is an abundantly available, inexpensive aromatic resource that is regarded as a low value compound by the pulp and paper industry, necessitating the development of new applications.

  2. The Kraft Pulp And Paper Properties of Sweet Sorghum Bagasse (Sorghum bicolor L Moench

    Directory of Open Access Journals (Sweden)

    Widya Fatriasari

    2015-05-01

    Full Text Available This study investigated the potency of sweet sorghum (Sorghum bicolor bagasse as raw material for pulp and paper using kraft pulping. The effects of alkali and sulfidity loading on kraft pulp and paper properties were also investigated. The pulping condition of the kraft pulp consisted of three levels of alkali loading (17, 19 and 22% and sulfidity loading (20, 22 and 24%. The maximum cooking temperature was 170°C for 4 h with a liquid to wood ratio of 10:1. Kraft pulping of this Numbu bagasse produced good pulp indicated by high screen yield and delignification selectivity with a low Kappa number (< 10. The unbleached pulp sheet produced a superior brightness level and a high burst index. The increase of active alkali loading tended to produce a negative effect on the pulp yield, Kappa number and paper sheet properties. Therefore, it is suggested to use a lower active alkaline concentration.

  3. Kraft pulp bleaching with molybdenum activated acid peroxide (PMo stage)

    International Nuclear Information System (INIS)

    Rabelo, Marcos Sousa

    2009-01-01

    Optimum conditions to run the P Mo stage for bleaching eucalyptus kraft pulp were 90 deg C, pH 3.5, 2 h, 0.1 kg/t Mo and 5 kg/t H 2 O 2 . The P Mo stage efficiency increased with decreasing pH (1.5-5.5) and increasing temperature (75-90 deg C), time (2-4 h), and hydrogen peroxide (3-10 kg/t) and molybdenum concentration (0.1-0.4 kg/t). The implementation of the P Mo stage, as replacement for the A stage, decreased total active chlorine demand of the OAZDP sequence by 6 kg/t to reach 90% ISO, both in laboratory and mill scale. Such practice resulted in decreased bleaching chemical costs to produce fully bleached pulp of 90% ISO. (author)

  4. Conversion of kraft lignin over hierarchical MFI zeolite.

    Science.gov (United States)

    Kim, Seong-Soo; Lee, Hyung Won; Ryoo, Ryong; Kim, Wookdong; Park, Sung Hoon; Jeon, Jong-Ki; Park, Young-Kwon

    2014-03-01

    Catalytic pyrolysis of kraft lignin was carried out using pyrolysis gas chromatography/mass spectrometry. Hierarchical mesoporous MFI was used as the catalyst and another mesoporous material Al-SBA-15 was also used for comparison. The characteristics of mesoporous MFI were analyzed by X-ray diffraction patterns, N2 adsorption-desorption isotherms, and temperature programmed desorption of NH3. Two catalyst/lignin mass ratios were tested: 5/1 and 10/1. Aromatics and alkyl phenolics were the main products of the catalytic pyrolysis of lignin over mesoporous MFI. In particular, the yields of mono-aromatics such as benzene, toluene, ethylbenzene, and xylene were increased substantially by catalytic upgrading. Increase in the catalyst dose enhanced the production of aromatics further, which is attributed to decarboxylation, decarbonlyation, and aromatization reactions occurring over the acid sites of mesoporous MFI.

  5. Study on the Modification of Bleached Eucalyptus Kraft Pulp Using Birch Xylan

    Science.gov (United States)

    Wenjia Han; Chuanshan Zhao; Thomas Elder; Rendang Yang; Dongho Kim; Yunqiao Pu; Jeffery Hsieh; Arthur J. Ragauskas

    2012-01-01

    In this study, birch xylan was deposited onto elementally chlorine free (ECF) bleached eucalyptus kraft pulp, and the corresponding changes in physical properties were determined. An aqueous 5% birch xylan solution at pH 9 was added to 5 wt% slurry of bleached kraft eucalyptus fibers, with stirring at 70 C for 15 min after which the pH was adjusted to 5–6. The xylan...

  6. Negotiation time table and realization timetable in the grid connection process according to KraftNAV; Verhandlungs- und Realisierungsfahrplan im Netzanschlussverfahren nach der KraftNAV

    Energy Technology Data Exchange (ETDEWEB)

    Buchmann, Felix [Sozietaet Alber Buchmann Stefan Rechtsanwaelte, Reutlingen (Germany)

    2010-04-15

    With the ordinance for the regulation of the grid connection from plants of power production (KraftNAV), the conditions of the grid connection were concretized by power station projects with a nominal output of at least 100 MW with an electrical potential of at least 110 kV. Under this aspect, the author of the contribution under consideration reports on the negotiation timetable and realization timetable in the grid connection procedure according to the KraftNAV. The following aspects are treated: Procedure for the grid connection according to KraftNAV in the overview; Promise of the connection and reservation fee; Negotiation timetable; Realization timetable; Requirement timetable; Duties to supply information.

  7. Caracterização de compostos reduzidos de enxofre gerados na produção de celulose kraft e pré-hidrólise kraft.

    Directory of Open Access Journals (Sweden)

    Afonso Moraes de Moura

    2010-08-01

    Full Text Available Um problema ambiental da indústria de celulose kraft é o odor causado pela emissão dos compostos reduzidos de enxofre gerados pela deslignificação de madeiras de um modo em geral. Para monitorar essas emissões, existem equipamentos simples, desenvolvidos para a medição contínua do "total reduced sulphur" (TRS, tal como o analisador coulométrico. Neste trabalho, foram analisados sulfeto de hidrogênio (H2S, metil mercaptana (CH3SH, dimetil sulfeto [(CH32S] e dimetil dissulfeto [(CH32S2], gerados em deslignificações laboratoriais kraft e pré-hidrólise kraft de dois grupos de madeiras de folhosas. Um dos grupos de madeiras continha 25% e o outro 20% de lignina, base peso seco. Foi observado que as madeiras com menores teores de lignina geraram significativamente menores quantidades de compostos reduzidos de enxofre de TRS. Não foram notadas diferenças significativas nas quantidades totais geradas entre os processos de deslignificação estudados. O processo pré-hidrólise kraft foi mais sensível aos teores de lignina da madeira que o processo kraft. Recomenda-se, por isso, trabalhar com madeiras com menores teores de lignina quando do uso do processo pré-hidrólise kraft para produção de celulose. As principais formas geradas de TRS foram dimetil sulfeto e metil mercaptana.

  8. Two-dimensional finite element heat transfer model of softwood. Part II, Macrostructural effects

    Science.gov (United States)

    Hongmei Gu; John F. Hunt

    2006-01-01

    A two-dimensional finite element model was used to study the effects of structural features on transient heat transfer in softwood lumber with various orientations. Transient core temperature was modeled for lumber samples “cut” from various locations within a simulated log. The effects of ring orientation, earlywood to latewood (E/L) ratio, and ring density were...

  9. Political pressure: An examination of U S Senators actions in restricting Canadian softwood lumber imports

    Science.gov (United States)

    Joseph Godwin; Daowei Zhang

    2012-01-01

    Over the past 30 years the U.S.–Canadian softwood lumber trade dispute has resulted in three managed trade agreements that have not been voted on in the U.S. Congress. Nevertheless, U.S. Senators have played an important role in shaping the political environment that has nurtured these agreements. In this paper we construct a lumber influence index based on 14 known...

  10. A multi-criteria decision analysis of management alternatives for anaerobically digested kraft pulp mill sludge.

    Directory of Open Access Journals (Sweden)

    Martijn Eikelboom

    Full Text Available The Multi-Criteria Decision Analysis (MCDA procedure was used to compare waste management options for kraft pulp mill sludge following its anaerobic digestion. Anaerobic digestion of sludge is advantageous because it produces biogas that may be used to generate electricity, heat and biofuels. However, adequate management of the digested sludge is essential. Landfill disposal is a non-sustainable waste management alternative. Kraft pulp mill digested sludge applied to land may pose risks to the environment and public health if the sludge has not been properly treated. This study is aimed to compare several recycling alternatives for anaerobically digested sludge from kraft pulp mills: land application, landfill disposal, composting, incineration, pyrolysis/gasification, and biofuel production by algae. The MCDA procedure considered nine criteria into three domains to compare digested sludge recycling alternatives in a kraft pulp mill: environmental (CO2 emission, exposure to pathogens, risk of pollution, material and energy recovery, economic (overall costs, value of products and technical (maintenance and operation, feasibility of implementation. The most suitable management options for digested sludge from kraft pulp mills were found to be composting and incineration (when the latter was coupled with recycling ash to the cement industry. Landfill disposal was the worst option, presenting low performance in feasibility of implementation, risk of pollution, material and energy recovery.

  11. Papermaking Properties of Carpinus betulus with kraft, Soda and Soda-Urea Pulping Processes

    Directory of Open Access Journals (Sweden)

    Rasoul Darstan

    2013-06-01

    Full Text Available This research was carried out in order to comparatively investigate the hornbeam kraft, soda and soda-urea papermaking properties. The selected treatment in kraft process had an average yield of 44.43% and kappa number of 23.75. In soda process the selected treatment had an average yield of 38.75% and kappa number of 19.28. In soda-urea process, the selected treatments had an average yield of 39.85, 40.1, 40.5, 39.8 and 40.61 and kappa number of 21.21, 22.33, 22.66, 25.28 and 26.85. After refining the selected pulp to reach the freeness of 400±25 ml CSF, 60 g/m2 handsheets were made and physical, mechanical and optical properties were measured. Results showed that kraft pulps had higher yield and better refinability than soda and soda-urea pulps. Papers made from kraft process had higher strength properties than those made of soda and soda-urea process. With addition of urea, yield and kappa number of pulps increased. The highest improvement in tensile index, breaking length and tear index was achieved with addition of 3% urea and the highest improvement in burst index was achieved with adding 4% urea. Results of brightness measurements showed that papers from kraft and soda processes had the lowest and highest brightness degree respectively. With the addition of urea, brightness of papers decreased.

  12. A multi-criteria decision analysis of management alternatives for anaerobically digested kraft pulp mill sludge

    Science.gov (United States)

    Eikelboom, Martijn; Lopes, Alice do Carmo Precci; Silva, Claudio Mudadu; Rodrigues, Fábio de Ávila; Zanuncio, José Cola

    2018-01-01

    The Multi-Criteria Decision Analysis (MCDA) procedure was used to compare waste management options for kraft pulp mill sludge following its anaerobic digestion. Anaerobic digestion of sludge is advantageous because it produces biogas that may be used to generate electricity, heat and biofuels. However, adequate management of the digested sludge is essential. Landfill disposal is a non-sustainable waste management alternative. Kraft pulp mill digested sludge applied to land may pose risks to the environment and public health if the sludge has not been properly treated. This study is aimed to compare several recycling alternatives for anaerobically digested sludge from kraft pulp mills: land application, landfill disposal, composting, incineration, pyrolysis/gasification, and biofuel production by algae. The MCDA procedure considered nine criteria into three domains to compare digested sludge recycling alternatives in a kraft pulp mill: environmental (CO2 emission, exposure to pathogens, risk of pollution, material and energy recovery), economic (overall costs, value of products) and technical (maintenance and operation, feasibility of implementation). The most suitable management options for digested sludge from kraft pulp mills were found to be composting and incineration (when the latter was coupled with recycling ash to the cement industry). Landfill disposal was the worst option, presenting low performance in feasibility of implementation, risk of pollution, material and energy recovery. PMID:29298296

  13. Evaluation of bleachability on pine and eucalyptus kraft pulps

    Directory of Open Access Journals (Sweden)

    Marcela Freitas Andrade

    2013-09-01

    Full Text Available In recent decades, the pulp industry has been changing and improving its manufacturing processes in order to enhance production capacity, product quality and environmental performance. The aim of this study was to evaluate the bleachability effect on the efficient washing and alkaline leaching in eucalyptus and pine Kraft pulps using three different bleaching sequences: AD(EPD, A/D(EPDP and DHT(EPDP. This study was carried out in two stages. In the first part, the optimum conditions for pulp bleaching in order to achieve a brightness of 90% ISO were established. The second step was a comparative study between the pulps that received alkaline leaching and efficient washing with reference pulp (without treatment. The brightness, viscosity, kappa number and HexA in pulp were analyzed. The three sequences studied reached the desired brightness, but the sequence AD(EPD produced a lower reagent consumption for the same brightness. In the three sequences studied, the efficient washing of the pulp after oxygen delignification has contributed significantly to the removal of dissolved organic and inorganic materials in the pulp and the alkaline leaching decreased significantly the pulp kappa number due to a higher pulp delignification and bleachability.

  14. Characterization of Cypress Wood for Kraft Pulp Production

    Directory of Open Access Journals (Sweden)

    António J. A. Santos

    2014-06-01

    Full Text Available Wood samples of Cupressus arizonica, C. lusitanica, and C. sempervirens were evaluated for chemical, anatomical, and pulp characteristics as raw material for pulp production. Two 17-year-old trees per species were harvested, and wood samples were taken at a height of 2 m. Wood chips from Pinus pinaster (Portugal and P. sylvestris (Finland were used as references. C. arizonica differed from C. lusitanica and C. sempervirens with significantly lower (p < 0.05 tracheid diameter and wall thickness in the earlywood. The total extractives contents were 3.9%, 3.3%, and 2.5% for C. lusitanica, C. sempervirens, and C. arizonica, respectively, lower than the 5.1% for P. pinaster and 4.5% for P. sylvestris. Klason lignin content ranged from 33.0 to 35.6%, higher than the 28.0 to 28.7% for the pinewoods. The kraft pulp yields for C. arizonica, C. lusitanica, and C. sempervirens were 37.7%, 36.7%, and 38.7%, respectively, with kappa numbers of 32.0, 31.6, and 28.7, respectively; the yield values were 40.8% and 42.8%, with kappa numbers of 23.4 and 21.0, for P. pinaster and P. sylvestris, respectively. The cypress species are clearly different from pine in relation to wood pulping behavior. Among the cypress, C. sempervirens provided the best pulping results.

  15. Mesta/Kenaf as raw material for Kraft pulping

    Energy Technology Data Exchange (ETDEWEB)

    Saraf, V. P.; Shiveshwar, R. M.; Meshramkar, P. M.; Deb, U. K.; Jaspal, N. S.; Biyani, B. P.

    1980-03-15

    In recent years, the shortage of conventional raw materials for pulping has intensified a world-wide search for alternate raw materials. Among other cellulosic materials, attention has focused on agricultural residues and annual plants. In this category, Kenaf, also called Mesta, has been studied as a fiber source in many countries including the USA, Phillippines and India. A comprehensive study on kraft pulping of mesta was carried out where the fiber morphology, pulping, bleaching and papermaking characteristics were investigated. Black liquor properties were also determined. The results of this study are reported and compared to the conventional raw material bamboo. The investigation has shown that mesta is easily pulped and bleached and forms sheets of excellent strength properties, comparable to or better than bamboo pulps. The black liquor from mesta is similar to bamboo in calorific value but is very low in silica, which is highly desirable from the chemical recovery point of view. As with all agricultural residues and annual plants, mesta has a high bulk per unit weight. The problems arising from this, e.g., baling, transportation, proper utilization of digester capacity, have to be studied before mesta can be widely accepted in the paper industry.

  16. Performance of Schizolobium amazonicum Wood in Bleached Kraft Pulp Production

    Directory of Open Access Journals (Sweden)

    Camila Sarto

    2015-05-01

    Full Text Available This study aimed to evaluate the characteristics of Schizolobium amazonicum wood, specifically its performance in bleached kraft pulp production and the characteristics of its pulp. Chips of Schizolobium amazonicum and Eucalyptus grandis x Eucalyptus urophylla (reference were used. The following parameters were evaluated in the wood: basic density, total extractives, total lignin, holocellulose, and fiber morphology. The pulping simulations were carried out in a laboratory digester, with parameters set to obtain pulp with kappa number 19 ± 0.5. Both pulps were bleached in a PFI mill and submitted to physical-mechanical tests. The results showed that S. amazonicum wood has low basic density and higher content of extractives when compared to E. grandis x E. urophylla wood. For pulping, S. amazonicum required higher alkali charge and H factor to achieve the same delignification level of E. grandis x E. urophylla, resulting in a lower yield, pulp with lower viscosity, and higher wood specific consumption. During bleaching, the brightness gain and final viscosity of S. amazonicum pulp were lower than E. grandis x E. urophylla pulp. Moreover, S. amazonicum pulp had worse physical-mechanical characteristics than E. grandis x E. urophylla.

  17. Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

    NARCIS (Netherlands)

    Agarwal, Shilpa; Chowdari, Ramesh Kumar; Hita, Idoia; Heeres, Hero Jan

    Limonite, a low-cost iron ore, was investigated as a potential hydrotreatment catalyst for kraft lignin without the use of an external solvent (batch reactor, initial H-2 pressure of 100 bar, 4 h). The best results were obtained at 450 degrees C resulting in 34 wt % of liquefied kraft lignin (lignin

  18. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Science.gov (United States)

    2010-07-01

    ... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... operator of each pulping system using a semi-chemical or soda process subject to the requirements of this... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL...

  19. Simultaneous and rapid determination of multiple component concentrations in a Kraft liquor process stream

    Science.gov (United States)

    Li, Jian [Marietta, GA; Chai, Xin Sheng [Atlanta, GA; Zhu, Junyoung [Marietta, GA

    2008-06-24

    The present invention is a rapid method of determining the concentration of the major components in a chemical stream. The present invention is also a simple, low cost, device of determining the in-situ concentration of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously determining the concentrations of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples. The inventive method can be used in Kraft pulping operations to control white liquor causticizing efficiency, sulfate reduction efficiency in green liquor, oxidation efficiency for oxidized white liquor and the active and effective alkali charge to kraft pulping operations.

  20. Preferences of group-housed female mice regarding structure of softwood bedding.

    Science.gov (United States)

    Kirchner, J; Hackbarth, H; Stelzer, H D; Tsai, P-P

    2012-04-01

    Bedding influences various parameters in the housing of laboratory mice, such as health, physiology and behaviour (often considered as being integral parts of welfare). Notwithstanding existent studies about bedding preferences of individually tested mice, data about group-housed mice are still lacking. The aim of this study was to find out the structure preference for softwood bedding of group-housed mice. One hundred and eight 8-week-old female mice (C57BL6/JOlaHsd and BALB/cOlaHsd) were housed in groups of three and were given one-week free access to two different bedding structures at a time. In three test combinations, softwood shaving bedding was tested versus softwood chip bedding products of three different particle sizes (fine/medium/coarse-grained). The preference test was performed in a DoubleCage system composed of two Makrolon type IIL cages, connected by a perspex tunnel. This validated system was able to detect the crossings of each individual animal with correct crossing time and direction. On the basis of these data, dwelling times on the particular bedding structures were statistically analysed as a parameter for bedding preferences. In all three test combinations, a highly significant shaving preference was detected. On average, mice spent 70% of their dwelling time on the shavings. This preference was more explicit during the light period and in C57BL/6J mice. The relative ranking of the bedding structures was: shavings > coarse-grained chips > medium chips = fine chips. By means of these results, a shaving structure as bedding can be recommended for laboratory mice, whereas fine chip structures should be avoided.

  1. Numerical modelling of softwood time-dependent behaviour based on microstructure

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2010-01-01

    The time-dependent mechanical behaviour of softwood such as creep or relaxation can be predicted, from knowledge of the microstructural arrangement of the cell wall, by applying deformation kinetics. This has been done several times before; however, often without considering the constraints defined...... by the basic physical mechanism behind the time-dependent behaviour. The mechanism causing time-dependency is thought to be sliding of the microfibrils past each other as a result breaking and re-bonding of hydrogen bonds. This can be incorporated in a numerical model by only allowing time-dependency in shear...

  2. Antraquinona e surfactante para otimizaçao do processo Kraft com Pinus Spp.

    OpenAIRE

    Mocelin, Ezequiel Zatoni

    2013-01-01

    A madeira de Pinus é atualmente a matéria-prima mais utilizada na obtenção de fibras longas para papel, juntamente com o processo Kraft pela sua versatilidade e por produzir fibras com boa resistência. As atuais perspectivas florestais apontam para uma escassez da madeira de Pinus para os diversos fins, seja para madeira processada, seja para celulose e papel. O processo Kraft tem como desvantagem o baixo rendimento em celulose, devido à solubilização não somente da lignina como também parte ...

  3. Antioxidant capacity of Kraft black liquor from the pulp and paper industry.

    Science.gov (United States)

    Perez-Perez, Elizabeth; Rodríguez-Malaver, Antonio J

    2005-07-01

    The effect of Kraft black liquor on the lipid peroxidation of rat homogenates was examined. The lipid peroxidation of homogenates from different organs (kidney, brain, lung, and liver) was induced by Fenton's reagent. The products of lipid peroxidation, lipid hydroperoxides and TBARS were measured by FOX method and TBA assay, respectively. It was found that black liquor significantly reduced the concentration of TBARS, but not the concentration of lipid hydroperoxides. This inhibition was directly proportional to the concentration of Kraft black liquor and the incubation temperature. Conclusively, the black liquor from pulp and paper industry exhibited an antioxidant activity.

  4. Detoxification of kraft pulp ECF bleaching effluents by catalytic hydrotreatment.

    Science.gov (United States)

    Calvo, L; Gilarranz, M A; Casas, J A; Mohedano, A F; Rodríguez, J J

    2007-02-01

    Two different effluents from the D(1) and E(1) stages of the ECF bleaching of Eucalyptus globulus kraft pulp were treated by catalytic hydrogenation in a trickle bed reactor using commercial and homemade Pd/AC catalysts. The reactor was fed with the bleaching effluent and a H(2)/N(2) gas stream. The variables studied were space-time (1.4-5g(cat)min/mL), gas to liquid flow ratio (286-1000vol.), gas feed concentration (H(2):N(2), 1:1-1:7.3vol.), temperature (25-100 degrees C) and pressure (1-11bar). Hydrotreatment performance was evaluated in terms of ecotoxicity, adsorbable organic halogen (AOX), chemical oxygen demand (COD), biological oxygen demand (BOD(5)) and colour removal. In all the runs, the ecotoxicity of the effluents decreased as a result of the treatment, achieving reductions that ranged from 70% to 98%. Simultaneously to the reduction of toxicity, the hydrotreatment led to a decrease of the colour of the effluents, being the decrease significantly higher in the case of E(1) effluent. The AOX content was reduced by 85% and 23% for E(1) and D(1) effluents, respectively. In the case of D(1) effluent the removal of ecotoxicity was significantly higher than that of AOX, which indicates that much of the toxicity of the effluent must be associated to non-chlorinated organics. In spite of the important reduction of ecotoxicity, the biodegradability of the effluents only increased slightly. The homemade catalysts, prepared from activated carbons with a high external or non-microporous surface area and mesopore volume and a convenient surface chemistry showed a higher efficiency than the commercial one.

  5. Dry Kraft Pulping at Ambient Pressure for Cost Effective Energy Saving and Pollution Deduction

    Energy Technology Data Exchange (ETDEWEB)

    Yulin Deng; Art Ragauskas

    2012-08-28

    Sponsored by the DOE Industrial Energy Efficiency Grand Challenge program, our research team at the Georgia Institute of Technology conducted laboratory studies and confirmed the concept of making wood pulp using a dry pulping technology. This technology is a new process different from any prior pulping technology used in Kraft and CTMP pulping. Three different kinds of dry pulping methods were investigated. (a) Dry Pulping at Atmospheric Pressure: The first one is to dry and bake the pretreated woodchips in a conventional oven at atmospheric pressure without the use of a catalyst. (b) Dry Pulping at Reduced Pressure: The second method is to dry the pretreated woodchips first in a vacuum oven in the presence of anthraquinone (AQ) as a pulping catalyst, followed by baking at elevated temperature. (c) Liquid Free Chemical Pulping, LFCP. The third method is to first remove the free water of pretreated woodchips, followed by dry pulping using a conventional Kraft pulping digester with AQ and triton as additives. Method one: Experimental results indicated that Dry Pulping at Atmospheric Pressure could produce pulp with higher brightness and lower bulk than conventional Kraft pulp. However, tensile strength of the acquired pulp is much lower than traditional Kraft pulp, and their Kappa number and energy consumption are higher than conventional Kraft pulp. By fully analyzing the results, we concluded that wood fibers might be damaged during the drying process at elevated temperature. The main reason for wood fiber damage is that a long drying time was used during evaporation of water from the woodchips. This resulted in an un-uniform reaction condition on the woodchips: the outside layer of the woodchips was over reacted while inside the woodchips did not reacted at all. To solve this problem, dry pulping at reduced pressure was investigated. Method two: To achieve uniform reaction throughout the entire reaction system, the water inside the pretreated woodchips was

  6. DEMONSTRATION OF EQUIVALENCY OF CANE AND SOFTWOOD BASED CELOTEX FOR MODEL 9975 SHIPPING PACKAGES

    International Nuclear Information System (INIS)

    Watkins, R; Jason Varble, J

    2008-01-01

    Cane-based Celotex(trademark) has been used extensively in various Department of Energy (DOE) packages as a thermal insulator and impact absorber. Cane-based Celotex(trademark) fiberboard was only manufactured by Knight-Celotex Fiberboard at their Marrero Plant in Louisiana. However, Knight-Celotex Fiberboard shut down their Marrero Plant in early 2007 due to impacts from hurricane Katrina and other economic factors. Therefore, cane-based Celotex(trademark) fiberboard is no longer available for use in the manufacture of new shipping packages requiring the material as a component. Current consolidation plans for the DOE Complex require the procurement of several thousand new Model 9975 shipping packages requiring cane-based Celotex(trademark) fiberboard. Therefore, an alternative to cane-based Celotex(trademark) fiberboard is needed. Knight-Celotex currently manufactures Celotex(trademark) fiberboard from other cellulosic materials, such as hardwood and softwood. A review of the relevant literature has shown that softwood-based Celotex(trademark) meets all parameters important to the Model 9975 shipping package

  7. Removal of Water-Soluble Extractives Improves the Enzymatic Digestibility of Steam-Pretreated Softwood Barks.

    Science.gov (United States)

    Frankó, Balázs; Carlqvist, Karin; Galbe, Mats; Lidén, Gunnar; Wallberg, Ola

    2018-02-01

    Softwood bark contains a large amounts of extractives-i.e., soluble lipophilic (such as resin acids) and hydrophilic components (phenolic compounds, stilbenes). The effects of the partial removal of water-soluble extractives before acid-catalyzed steam pretreatment on enzymatic digestibility were assessed for two softwood barks-Norway spruce and Scots pine. A simple hot water extraction step removed more than half of the water-soluble extractives from the barks, which improved the enzymatic digestibility of both steam-pretreated materials. This effect was more pronounced for the spruce than the pine bark, as evidenced by the 30 and 11% glucose yield improvement, respectively, in the enzymatic digestibility. Furthermore, analysis of the chemical composition showed that the acid-insoluble lignin content of the pretreated materials decreased when water-soluble extractives were removed prior to steam pretreatment. This can be explained by a decreased formation of water-insoluble "pseudo-lignin" from water-soluble bark phenolics during the acid-catalyzed pretreatment, which otherwise results in distorted lignin analysis and may also contribute to the impaired enzymatic digestibility of the barks. Thus, this study advocates the removal of extractives as the first step in the processing of bark or bark-rich materials in a sugar platform biorefinery.

  8. WHITE PAPER: DEMONSTRATION OF EQUIVALENCY OF CANE AND SOFTWOOD BASED CELOTEX FOR 9975 PACKAGING

    International Nuclear Information System (INIS)

    Varble, J

    2007-01-01

    Cane-based Celotex(trademark) has been used extensively in various DOE packages as a thermal insulator and impact absorber. Cane-based Celotex(trademark) for the 9975 was manufactured by Knight-Celotex Fiberboard at their Marrero Plant in Louisiana. However, Knight-Celotex Fiberboard shut down their Marrero Plant in early 2007 due to impacts from hurricane Katrina and other economic factors. Therefore, cane-based Celotex(trademark) is no longer available for use in the manufacture of new 9975 packages. Knight-Celotex Fiberboard has Celotex(trademark) manufacturing plants in Danville, VA and Sunbury, PA that use softwood and hardwood, respectively, as a raw material in the manufacturing of Celotex(trademark). The purpose of this White Paper is to demonstrate that softwood-based Celotex(trademark) from the Knight-Celotex Danville Plant has performance equivalent to cane-based Celotex(trademark) from the Knight-Celotex Marrero Plant for transportation in a 9975 package

  9. IN VITRO ANDROGENIC ACTIVITY OF KRAFT MILL EFFLUENT IS ASSOCIATED WITH MASCULINIZATION OF FEMALE FISH

    Science.gov (United States)

    In Vitro Androgenic Activity of Kraft Mill Effluent is Associated with Masculinization of Female Fish. Lambright, CS 1 , Parks, LG 1, Orlando, E 2, Guillette, LJ, Jr.2, Ankley, G 3, Gray, LE, Jr.1 , 1USEPA, NHEERL, RTP, NC, 2 University of Florida, Dept. of Zoology, Gainesville ...

  10. Effects of a Chitosan Coating Layer on the Surface Properties and Barrier Properties of Kraft Paper

    Directory of Open Access Journals (Sweden)

    Shanhui Wang

    2016-01-01

    Full Text Available Biodegradable chitosan can be applied as a coating on the surface of kraft paper in order to improve its barrier properties against water vapor and air. The food packaging industry can benefit from the addition of chitosan to its current packaging, and in turn reduce pollution from plastic packaging plants. This paper discusses the film formation of chitosan, the permeability of paper coated with a chitosan layer, and the influence on the paper’s surface and barrier properties under different process conditions. SEM (scanning electron microscope, AFM (atomic force microscope, ATR-FTIR (Fourier transmission infrared spectroscope with attenuated total reflection, and PDA (penetration dynamics analysis were used to analyze the properties of chitosan’s film formation and permeability. A controlled experiment showed that the chitosan layer was smoother than the surface of the uncoated kraft paper, had better film formation, and that there was no chitosan penetration through the kraft paper. The barrier properties against water vapor were strongest when there was a higher concentration of chitosan solution at the optimum pH, stirring speed, and those with a thicker coating on the kraft paper.

  11. Combustion properties of kraft black liquors; Mustalipeaen koostumuksen vaikutus lipeaen poltto-ominaisuuksiin

    Energy Technology Data Exchange (ETDEWEB)

    Alen, R.; Siistonen, H.; Heikkinen, T.; Malkavaara, P. [Jyvaeskylae Univ. (Finland)

    1996-12-01

    The aim of this work is to study the combustion properties of kraft black liquors from modified cooking. Both the industrial and laboratory-made black liquors are included. In addition, changes in the combustion properties of the spent liquors obtained by mixing prior to combustion different chlorine-free bleach liquors with black liquor are studied. (author)

  12. Reinforcing Natural Rubber with Cellulose Nanofibrils Extracted from Bleached Eucalyptus Kraft Pulp

    Science.gov (United States)

    Chunmei Zhang; Tianliang Zhai; Ronald Sabo; Craig Clemons; Yi Dan; Lih-Sheng Turng

    2014-01-01

    Reinforced natural rubber (NR) nanocomposites were prepared by solution mixing, casting, and evaporation of pre-vulcanized natural rubber latex and an aqueous suspension of cellulose nanofibrils (CNFs) extracted from bleached eucalyptus kraft pulp. Scanning electron microscopy (SEM) images showed that there were no micro-scaled aggregates observed in the nanocomposites...

  13. Solution blow spun nanocomposites of poly(lactic acid)/cellulose nanocrystals from Eucalyptus kraft pulp

    Science.gov (United States)

    Cellulose nanocrystals (CNCs) were extracted from Eucalyptus kraft pulp by sulfuric acid hydrolysis, and esterified with maleic anhydride (CNCMA). The incorporation of sulfate ester groups on the cellulose surface resulted in higher stability of the nanoparticles in aqueous suspensions and lower the...

  14. An environmental systems analysis of the Kraft pulp industry in Thailand

    NARCIS (Netherlands)

    Warit, J.

    2006-01-01

    The pulp industry inThailandis of economic and social importance because of its production value, the revenues from export and the employment in this sector. The eucalyptus-based Kraft pulp industry plays an

  15. Kraft cooking of gamma irradiated wood, (1). Effect of alcohol additives on pre-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, M; Meshitsuka, G; Nakano, J [Tokyo Univ. (Japan). Faculty of Agriculture

    1979-12-01

    Studies have been made of kraft cooking of gamma irradiated wood. Beech (Fagus crenata Blume) wood meal suspended in aqueous alkaline alcohol was irradiated up to 1.5 KGy (0.15 Mrad) with gamma rays from a Co-60 source in the presence or absence of oxygen. The irradiated wood meals were washed thoroughly with fresh water, air dried and cooked under the ordinary cooking conditions. The results are summarized as follows: (1) Pre-irradiation in aqueous alkali have negligible effect on kraft cooking. (2) In the case of ethanol addition (50 g/l), pre-irradiation in vacuo shows acceleration of delignification and stabilization of carbohydrates during kraft cooking. Cooked yield gain by pre-irradiation was about 1.2 in all, over the range of delignification from 80 to 90%. Aqueous ethanol without alkali also shows positive but smaller effect than that with alkali. (3) Propanol, iso-propanol and butanol show positive but smaller effects than ethanol. However, methanol does not show any positive effect. (4) Irradiation in the presence of oxygen does not show any attractive effect on kraft cooking.

  16. Kinetics of Strong Acid Hydrolysis of a Bleached Kraft Pulp for Producing Cellulose Nanocrystals (CNCs)

    Science.gov (United States)

    Qianqian Wang; Xuebing Zhao; J.Y. Zhu

    2014-01-01

    Cellulose nanocrytals (CNCs) are predominantly produced using the traditional strong acid hydrolysis process. In most reported studies, the typical CNC yield is low (approximately 30%) despite process optimization. This study investigated the hydrolysis of a bleached kraft eucalyptus pulp using sulfuric acid between 50 and 64 wt % at temperatures of 35−80 °C...

  17. Development of hemicelluloses biorefineries for integration into kraft pulp mills

    Science.gov (United States)

    Ajao, Olumoye Abiodun

    The development and wide spread acceptance of production facilities for biofuels, biochemicals and biomaterials is an important condition for reducing reliance on limited fossil resources and transitioning towards a global biobased economy. Pulp and paper mills in North America are confronted with high energy prices, high production costs and intense competition from emerging economies and low demand for traditional products. Integrated forest biorefineries (IFBR) have been proposed as a mean to diversify their product streams, increase their revenue and become more sustainable. This is feasible because they have access to forest biomass, an established feedstock supply chain and wood processing experience. In addition, the integration of a biorefinery process that can share existing infrastructure and utilities on the site of pulp mill would significantly lower investment cost and associated risks. Kraft pulping mills are promising receptor processes for a biorefinery because they either possess a prehydrolysis step for extracting hemicelluloses sugars prior to wood pulping or it can be added by retrofit. The extracted hemicelluloses could be subsequently transformed into a wide range of value added products for the receptor mill. To successfully implement hemicelluloses biorefinery, novel processes that are technically and economically feasible are required. It is necessary to identify products that would be profitable, develop processes that are energy efficient and the receptor mill should be able to supply the energy, chemicals and material demands of the biorefinery unit. The objective of this thesis is to develop energy efficient and economically viable hemicelluloses biorefineries for integration into a Kraft pulping process. A dissolving pulp mill was the reference case study. The transformation of hemicellulosic sugars via a chemical and biochemical conversion pathway, with furfural and ethanol as representative products for each pathway was studied. In

  18. Life Cycle Primary Energy and Carbon Analysis of Recovering Softwood Framing Lumber and Hardwood Flooring for Reuse

    Science.gov (United States)

    Richard D. Bergman; Hongmei Gu; Thomas R. Napier; James Salazar; Robert H. Falk

    2012-01-01

    Recovering wood for reuse in a new house affects energy and greenhouse gas emissions. This paper finds the energy and emissions for recovering softwood framing lumber and hardwood flooring from an old house for installation in a new house. Recovering wood displaces primary production of new wood products and avoids the end-of-life (EOL) burdens for the old house. We...

  19. Two-dimensional finite element heat transfer model of softwood. Part III, Effect of moisture content on thermal conductivity

    Science.gov (United States)

    Hongmei Gu; John F. Hunt

    2007-01-01

    The anisotropy of wood creates a complex problem for solving heat and mass transfer problems that require analyses be based on fundamental material properties of the wood structure. Most heat transfer models for softwood use average thermal properties across either the radial or tangential direction and do not differentiate the effects of cellular alignment or...

  20. Composite tube cracking in kraft recovery boilers: A state-of-the-art review

    Energy Technology Data Exchange (ETDEWEB)

    Singbeil, D.L.; Prescott, R. [Pulp and Paper Research Inst. of Canada, Vancouver, British Columbia (Canada); Keiser, J.R.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-07-01

    Beginning in the mid-1960s, increasing energy costs in Finland and Sweden made energy recovery more critical to the cost-effective operation of a kraft pulp mill. Boiler designers responded to this need by raising the steam operating pressure, but almost immediately the wall tubes in these new boilers began to corrode rapidly. Test panels installed in the walls of the most severely corroding boiler identified austenitic stainless steel as sufficiently resistant to the new corrosive conditions, and discussions with Sandvik AB, a Swedish tube manufacturer, led to the suggestion that coextruded tubes be used for water wall service in kraft recovery boilers. Replacement of carbon steel by coextruded tubes has solved most of the corrosion problems experienced by carbon steel wall tubes, however, these tubes have not been problem-free. Beginning in early 1995, a multidisciplinary research program funded by the US Department of Energy was established to investigate the cause of cracking in coextruded tubes and to develop improved materials for use in water walls and floors of kraft recovery boilers. One portion of that program, a state-of-the-art review of public- and private-domain documents related to coextruded tube cracking in kraft recovery boilers is reported here. Sources of information that were consulted for this review include the following: tube manufacturers, boiler manufacturers, public-domain literature, companies operating kraft recovery boilers, consultants and failure analysis laboratories, and failure analyses conducted specifically for this project. Much of the information contained in this report involves cracking problems experienced in recovery boiler floors and those aspects of spout and air-port-opening cracking not readily attributable to thermal fatigue. 61 refs.

  1. Centrifugal washing and recovery as an improved method for obtaining lignin precipitated from South African kraft mill black liquor

    CSIR Research Space (South Africa)

    Namane, M

    2015-10-01

    Full Text Available This study describes centrifugal recovery as an improved method for collection of lignin isolated from black liquor obtained from a South African kraft mill. Precipitation of lignin was achieved by utilising 6 M sulphuric acid. Recovery...

  2. Investigation of ESEM/EDX to measure liquor penetration and diffusion in Eucalyptus grandis wood chips during kraft pulping

    CSIR Research Space (South Africa)

    Grzeskowiak, V

    2011-01-01

    Full Text Available Environmental scanning electron microscopy coupled with energy dispersive x-ray (ESEM/EDX) was optimised to measure the penetration and diffusion of cooking liquor into Eucalyptus grandis wood chips during kraft pulping. The moisture content...

  3. Prediction of Five Softwood Paper Properties from its Density using Support Vector Machine Regression Techniques

    Directory of Open Access Journals (Sweden)

    Esperanza García-Gonzalo

    2016-01-01

    Full Text Available Predicting paper properties based on a limited number of measured variables can be an important tool for the industry. Mathematical models were developed to predict mechanical and optical properties from the corresponding paper density for some softwood papers using support vector machine regression with the Radial Basis Function Kernel. A dataset of different properties of paper handsheets produced from pulps of pine (Pinus pinaster and P. sylvestris and cypress species (Cupressus lusitanica, C. sempervirens, and C. arizonica beaten at 1000, 4000, and 7000 revolutions was used. The results show that it is possible to obtain good models (with high coefficient of determination with two variables: the numerical variable density and the categorical variable species.

  4. New models for estimating the carbon sink capacity of Spanish softwood species

    International Nuclear Information System (INIS)

    Ruiz-Peinado, R.; Rio, M. del; Montero, G.

    2011-01-01

    Quantifying the carbon balance in forests is one of the main challenges in forest management. Forest carbon stocks are usually estimated indirectly through biomass equations applied to forest inventories, frequently considering different tree biomass components. The aim of this study is to develop systems of equations for predicting tree biomass components for the main forest softwood species in Spain: Abies alba Mill., A. pinsapo Boiss., Juniperus thurifera L., Pinus canariensis Sweet ex Spreng., P. halepensis Mill., P. nigra Arn., P. pinaster Ait., P. pinea L., P. sylvestris L., P. uncinata Mill. For each species, a system of additive biomass models was fitted using seemingly unrelated regression. Diameter at the breast height and total height were used as independent variables. Diameter appears in all component models, while tree height was included in the stem component model of all species and in some branch component equations. Total height was included in order to improve biomass estimations at different sites. These biomass models were compared to previously available equations in order to test their accuracy and it was found that they yielded better fitting statistics in all cases. Moreover, the models fulfil the additivity property. We also developed root:shoot ratios in order to determine the partitioning into aboveground and belowground biomass. A number of differences were found between species, with a minimum of 0.183 for A. alba and a maximum of 0.385 for P. uncinata. The mean value for the softwood species studied was 0.265. Since the Spanish National Forest Inventory (NFI) records species, tree diameter and height of sample trees, these biomass models and ratios can be used to accurately estimate carbon stocks from NFI data. (Author) 55 refs.

  5. New models for estimating the carbon sink capacity of Spanish softwood species

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Peinado, R.; Rio, M. del; Montero, G.

    2011-07-01

    Quantifying the carbon balance in forests is one of the main challenges in forest management. Forest carbon stocks are usually estimated indirectly through biomass equations applied to forest inventories, frequently considering different tree biomass components. The aim of this study is to develop systems of equations for predicting tree biomass components for the main forest softwood species in Spain: Abies alba Mill., A. pinsapo Boiss., Juniperus thurifera L., Pinus canariensis Sweet ex Spreng., P. halepensis Mill., P. nigra Arn., P. pinaster Ait., P. pinea L., P. sylvestris L., P. uncinata Mill. For each species, a system of additive biomass models was fitted using seemingly unrelated regression. Diameter at the breast height and total height were used as independent variables. Diameter appears in all component models, while tree height was included in the stem component model of all species and in some branch component equations. Total height was included in order to improve biomass estimations at different sites. These biomass models were compared to previously available equations in order to test their accuracy and it was found that they yielded better fitting statistics in all cases. Moreover, the models fulfil the additivity property. We also developed root:shoot ratios in order to determine the partitioning into aboveground and belowground biomass. A number of differences were found between species, with a minimum of 0.183 for A. alba and a maximum of 0.385 for P. uncinata. The mean value for the softwood species studied was 0.265. Since the Spanish National Forest Inventory (NFI) records species, tree diameter and height of sample trees, these biomass models and ratios can be used to accurately estimate carbon stocks from NFI data. (Author) 55 refs.

  6. Steam explosion pretreatment of softwood: the effect of the explosive decompression on enzymatic digestibility.

    Science.gov (United States)

    Pielhop, Thomas; Amgarten, Janick; von Rohr, Philipp Rudolf; Studer, Michael H

    2016-01-01

    Steam explosion pretreatment has been examined in many studies for enhancing the enzymatic digestibility of lignocellulosic biomass and is currently the most common pretreatment method in commercial biorefineries. The information available about the effect of the explosive decompression on the biochemical conversion is, however, very limited, and no studies prove that the latter is actually enhanced by the explosion. Hence, it is of great value to discern between the effect of the explosion on the one hand and the steaming on the other hand, to identify their particular influences on enzymatic digestibility. The effect of the explosive decompression in the steam explosion pretreatment of spruce wood chips on their enzymatic cellulose digestibility was studied systematically. The explosion had a high influence on digestibility, improving it by up to 90 % compared to a steam pretreatment without explosion. Two factors were identified to be essentially responsible for the effect of the explosion on enzymatic digestibility: pretreatment severity and pressure difference of the explosion. A higher pretreatment severity can soften up and weaken the lignocellulose structure more, so that the explosion can better break up the biomass and decrease its particle size, which enhances its digestibility. In particular, increasing the pressure difference of the explosion leads to more defibration, a smaller particle size and a better digestibility. Though differences were found in the micro- and nanostructure of exploded and non-exploded biomass, the only influence of the explosion on digestibility was found to be the macroscopic particle size reduction. Steam explosion treatments with a high severity and a high pressure difference of the explosion lead to a comparatively high cellulose digestibility of the-typically very recalcitrant-softwood biomass. This is the first study to show that explosion can enhance the enzymatic digestibility of lignocellulosic biomass. If the

  7. Study of root tensile strength of softwood and hardwood tree species: Implications for slope stability

    Science.gov (United States)

    Esmaiili, Marzieh; Abdi, Ehsan; Jafary, Mohammad; Majnounian, Baris

    2017-04-01

    Landslides are known as one of the major natural hazards and often incurring economics and human life losses. The role of tree roots in slope stability is very important, especially when human lives and infrastructure are at risk. The anchorage of roots and improvement of slope stability mainly depend on specific properties of root network systems, such as tensile strength. These properties of the roots which govern the degree of reinforcement are different among tree species. Although, many studies have been conducted about plant biotechnical properties of species, yet there is lack of knowledge on comparing root systems of softwood and hardwood tree species for similar site conditions. Therefore this study was conducted to assess the tensile strength of the root system of Picea abies (softwood species) and Fraxinus excelsior (hardwood species) planted on two forested hillslopes. To this aim, single root specimens were sampled for each species and their tensile strength were then measured in laboratory using a computer controlled Instron Universal Testing Machine. According to the results root tensile strength tends to decrease with diameter according to a power law for both species. Based on analysis of covariance (ANCOVA), a significant difference has been observed in the tensile strength between the two studied species. Also the results showed that the value of mean root tensile strength for Picea abies (19.31 ± 2.64 MPa) was much more than that of Fraxinus excelsior (16.98 ± 1.01 MPa) within all root diameter classes. The data presented in this study may expand the knowledge of biotechnical properties of Picea abies and Fraxinus excelsior, as biomaterial for soil bioengineering.

  8. EFFECT OF LIGNIN CONTENT OF Eucalyptus globulus WOOD IN KRAFT PULPING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Gabriel Valim Cardoso

    2011-03-01

    Full Text Available In this research, it was analyzed the lignin content effect of Eucalyptus globulus wood in kraft pulping optimization. Seventy-two laboratory cooking were made with wood chips obtained from six Eucalyptus globulus trees selected from a group of 50 trees. The wood chips from three trees with the lowest lignin content, with average 20,53%, were mixed proportionally based on the tree weights, obtaining the sample of low lignin content wood. The same was made to obtain the sample for wood chips with the highest lignin content, with average 23,02%. The two lignin levels were statistically different. The two wood samples had basic densities statistically not different. Using three maximum temperatures levels (160, 165 and 170ºC, and three active alkali charged (17, 18,5 and 20%, the wood chips were converted to kraft pulps. The pulps were then characterized to analyze the influence of the distinct treatments employed in the cooking on their properties. The effect of the cooking conditions was expressed by mathematical models in order to determine the optimum points for each of the evaluated properties. The optimization process indicated maximum temperature of 168ºC, and active alkali of 19%, for maximum kraft pulping yield to achieve kappa number 18; this result was for woods with low lignin content. For woods containing the high lignin content, the optimization showed maximum cooking temperature of 169ºC and active alkali of 19% for kappa number of 18. The average reduction of 2,49% in wood lignin content resulted a correspondent gain of 2,2% in the kraft yield (o.d. basis and a reduction on the active alkali charge of 1,2% (o.d. basis to achieve kappa numbers from 16 to 19, preserving pulp properties. If the option is to work with kappa number 19 instead of 16, the gain in kraft yield is approximately 2%. Therefore, when working with low lignin content wood and kappa number 19 instead of 16, a substantial gain of approximately 4,2% is obtained

  9. Relationship between lignin structure and delignification degree in Pinus pinaster kraft pulps.

    Science.gov (United States)

    Baptista, C; Robert, D; Duarte, A P

    2008-05-01

    This study examines the structure of residual and dissolved lignins from Pinus pinaster pulps obtained at different degrees of delignification by laboratory conventional kraft pulping. The cooking H factor was varied from 85 to 8049. The residual and dissolved lignin samples were characterised by elemental analysis, residual carbohydrate content, permanganate oxidation and 13C NMR spectroscopy. The reflectance factor of the pulps was also determined in order to tentatively correlate the delignification degree and residual lignin structure with the pulp colour. The obtained results confirmed that the delignification degree increases the condensation of the lignin structure, which might have an influence upon the observed increased pulp colour. The lack of selectivity of kraft pulping process in the case of more delignified pulps was also shown.

  10. Application of Alkaline Ionic Liquids in the Pretreatment Process of Eucalyptus Kraft Pulping

    Directory of Open Access Journals (Sweden)

    Yi Hou

    2016-09-01

    Full Text Available In order to explore the potential application of green solvent ionic liquids (ILs in the kraft pulping process, eucalyptus wood was pretreated by [Mmim]DMP before normal pulping. The results showed that materials pretreated shortly by the ionic liquid had a higher yield and viscosity coupled with a lower potassium permanganate value and residual lignin content in the pulp, as a result of the cooking process. It was also inferred that alkaline [Mmim]DMP pretreatment could dissolve lignin effectively from fiber to result in a stronger binding force and more entangled properties. Paper tensile and burst strength were improved by about 40% and 60%, respectively. These results provide a new way for eucalyptus to be utilized in the kraft pulping process.

  11. Alternative Technologies for Biofuels Production in Kraft Pulp Mills—Potential and Prospects

    Directory of Open Access Journals (Sweden)

    Esa Vakkilainen

    2012-07-01

    Full Text Available The current global conditions provide the pulp mill new opportunities beyond the traditional production of cellulose. Due to stricter environmental regulations, volatility of oil price, energy policies and also the global competitiveness, the challenges for the pulp industry are many. They range from replacing fossil fuels with renewable energy sources to the export of biofuels, chemicals and biomaterials through the implementation of biorefineries. In spite of the enhanced maturity of various bio and thermo-chemical conversion processes, the economic viability becomes an impediment when considering the effective implementation on an industrial scale. In the case of kraft pulp mills, favorable conditions for biofuels production can be created due to the availability of wood residues and generation of black liquor. The objective of this article is to give an overview of the technologies related to the production of alternative biofuels in the kraft pulp mills and discuss their potential and prospects in the present and future scenario.

  12. Characterization of solid wastes from kraft pulp industry for ceramic materials development purposes

    International Nuclear Information System (INIS)

    Rodrigues, L.R.; Francisco, M.A.C.O.; Sagrillo, V.P.D.; Louzada, D.M.; Entringer, J.M.S.

    2016-01-01

    The Kraft pulp industry generates a large amount of solid wastes. Due this large quantity, the target of this study is characterize inorganic solid wastes, dregs, grits and lime mud, from the step of reagents recovery of Kraft process, aiming evaluate the potentiality of their use as alternative raw material on development of ceramic materials. Initially, the wastes were dried and ground, then they were subjected to the following characterization techniques: pH analysis, particle size analysis, X ray fluorescence, X ray diffraction, differential thermal analysis and thermogravimetric analysis and scanning electron microscopy. According to the results, it may be concluded that these wastes could be used as raw material in production of red ceramic and luting materials. (author)

  13. Alkali-treated kraft lignin as a component in flakeboard eesins

    Science.gov (United States)

    Mon-Lin Kuo; Chung-Yun Hse; Dee-Hua Huang

    1991-01-01

    Southern pine kraft lignin was reacted with NaOH (15 and 20% based on dry lignin) at 170, 200, and 250°C for 30 and 60 min. Sweetgum flake boards bonded with phenolic resins containing 50% hydroxymethylated lignin prepared from some of the alkali treated lignins were compared with boards bonded with a neat PF resin. Results indicate that boards bonded with lignin-...

  14. Process parameters affecting the delignification of eucalyptus kraft pulp with peroxyacetic acid

    Directory of Open Access Journals (Sweden)

    Chandranupap, P.

    2004-11-01

    Full Text Available Various process parameters affecting eucalyptus kraft pulp delignification with peroxyacetic acid were investigated. The results showed that pH was an important factor. The delignification rate increased with increasing pH to the value of 6. High delignification rate was obtained when the pulp was chelated with Na4-EDTA prior to the peroxyacetic acid stage. Therefore, delignification reaction rate depends on peroxyacid charge, temperature, pH and metal content of pulp.

  15. The energy efficiency partnership - Kraft General Foods and Boston Edison Company

    International Nuclear Information System (INIS)

    Crowley, J.C.; Donoghue, J.P.

    1993-01-01

    During the past twenty years, inordinate shifts in the supply and demand of energy have forced both electric utility companies and their customers to investigate new and innovative ways to satisfy the ever increasing demand for electricity. The Energy Efficiency Partnership, developed between Kraft General Foods and Boston Edison Company, presents an exemplary study of how two corporate giants creatively solved the problem of uncontrolled energy costs and its positive effect on the overall operations of Kraft General Foods, Framingham. But the Energy Efficiency Partnership did more than reduce energy costs, it provided benefits to all parties on the playing field. To understand its significance, a review of the partnership's history is paramount. The first official announcement of the Energy Efficiency Partnership was made on April 9, 1990. Framingham, MA, The Commonwealth of Massachusetts Kraft General Foods Framingham, and Boston Edison Company have joined forces in a $3.6 million dollar energy partnership that will help keep 250 industrial jobs in Massachusetts and could lead to the future expansion of the international food company's Framingham facility

  16. Biobutanol production by Clostridium acetobutylicum using xylose recovered from birch Kraft black liquor.

    Science.gov (United States)

    Kudahettige-Nilsson, Rasika L; Helmerius, Jonas; Nilsson, Robert T; Sjöblom, Magnus; Hodge, David B; Rova, Ulrika

    2015-01-01

    Acetone-butanol-ethanol (ABE) fermentation was studied using acid-hydrolyzed xylan recovered from hardwood Kraft black liquor by CO2 acidification as the only carbon source. Detoxification of hydrolyzate using activated carbon was conducted to evaluate the impact of inhibitor removal and fermentation. Xylose hydrolysis yields as high as 18.4% were demonstrated at the highest severity hydrolysis condition. Detoxification using active carbon was effective for removal of both phenolics (76-81%) and HMF (38-52%). Batch fermentation of the hydrolyzate and semi-defined P2 media resulted in a total solvent yield of 0.12-0.13g/g and 0.34g/g, corresponding to a butanol concentration of 1.8-2.1g/L and 7.3g/L respectively. This work is the first study of a process for the production of a biologically-derived biofuel from hemicelluloses solubilized during Kraft pulping and demonstrates the feasibility of utilizing xylan recovered directly from industrial Kraft pulping liquors as a feedstock for biological production of biofuels such as butanol. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Soda-anthraquinone, kraft and organosolv pulping of holm oak trimmings.

    Science.gov (United States)

    Alaejos, J; López, F; Eugenio, M E; Tapias, R

    2006-11-01

    The operating conditions for an organosolv (ethyleneglycol) and two alkaline (soda-anthraquinone and kraft) processes for obtaining cellulose pulp and paper from holm oak (Quercus ilex) wood trimmings were optimized. A range of variation for each process variable (viz. temperature, cooking time and soda or ethyleneglycol concentration) was established and a central composite experimental design involving three independent variables at three different variation levels was applied. The results obtained with the three cooking processes used were compared and those provided by the kraft process were found to be the best. Thus, the tensile index values it provided (5.9-16.3 N m/g) were 23.7% and 41.5% better than those obtained with the soda-AQ and ethyleneglycol processes, respectively. Also, the kraft process provided the best burst index, brightness and kappa number values. Based on the optimum working ranges, the temperature and cooking time were the variables resulting in the most and least marked changes, respectively, in pulp properties.

  18. Model Study To Assess Softwood Hemicellulose Hydrolysates as the Carbon Source for PHB Production in Paraburkholderia sacchari IPT 101.

    Science.gov (United States)

    Dietrich, Karolin; Dumont, Marie-Josée; Schwinghamer, Timothy; Orsat, Valérie; Del Rio, Luis F

    2018-01-08

    Softwood hemicellulose hydrolysates are a cheap source of sugars that can be used as a feedstock to produce polyhydroxybutyrates (PHB), which are biobased and compostable bacterial polyesters. To assess the potential of the hemicellulosic sugars as a carbon source for PHB production, synthetic media containing softwood hemicellulose sugars (glucose, mannose, galactose, xylose, arabinose) and the potentially inhibitory lignocellulose degradation products (acetic acid, 5-hydroxymethylfurfural (HMF), furfural, and vanillin) were fermented with the model strain Paraburkholderia sacchari IPT 101. Relative to pure glucose, individual fermentation for 24 h with 20 g/L mannose or galactose exhibited maximum specific growth rates of 97% and 60%, respectively. On the other hand, with sugar mixtures of glucose, mannose, galactose, xylose, and arabinose, the strain converted all sugars simultaneously to reach a maximum PHB concentration of 5.72 g/L and 80.5% PHB after 51 h. The addition of the inhibitor mixture at the following concentration, sodium acetate (2.11 g/L), HMF (0.67 g/L), furfural (0.66 g/L), and vanillin (0.93 g/L), to the sugar mixture stopped the growth entirely within 24 h. Individually, the inhibitors either had no effect or only reduced growth. Moreover, it was found that a bacterial inoculum with high initial cell density (optical density, OD ≥ 5.6) could overcome the growth inhibition to yield an OD of 13 within 24 h. Therefore, softwood hemicellulose sugars are viable carbon sources for PHB production. Nevertheless, real softwood hemicellulose hydrolysates need detoxification or a high inoculum to overcome inhibitory effects and allow bacterial growth.

  19. Decomposition and carbon storage of hardwood and softwood branches in laboratory-scale landfills

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoming, E-mail: wangxiaoming@cqu.edu.cn [Key Laboratory of Three Gorges Reservoir Region' s Eco-Environment under Ministry of Education, Chongqing University, Chongqing 400044 (China); Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Barlaz, Morton A. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States)

    2016-07-01

    Tree branches are an important component of yard waste disposed in U.S. municipal solid waste (MSW) landfills. The objective of this study was to characterize the anaerobic biodegradability of hardwood (HW) and softwood (SW) branches under simulated but optimized landfill conditions by measuring methane (CH{sub 4}) yields, decay rates, the decomposition of cellulose, hemicellulose and organic carbon, as well as carbon storage factors (CSFs). Carbon conversions to CH{sub 4} and CO{sub 2} ranged from zero to 9.5% for SWs and 17.1 to 28.5% for HWs. When lipophilic or hydrophilic compounds present in some of the HW and SW samples were extracted, some samples showed increased biochemical methane potentials (BMPs). The average CH{sub 4} yield, carbon conversion, and CSF measured here, 59.4 mL CH{sub 4} g{sup −1} dry material, 13.9%, and 0.39 g carbon stored g{sup −1} dry material, respectively, represent reasonable values for use in greenhouse gas inventories in the absence of detailed wood type/species data for landfilled yard waste. - Highlights: • Characterized biodegradation of branches under simulated but optimized landfill conditions • Observed varied biodegradation between HW and SW branches with different diameters • Inhibitory extractives were observed on boughs or twigs of some branch species. • CH{sub 4} yield and carbon storage factors presented for use in landfill related inventories.

  20. Use of softwood sawdust to amend reclaimed soils - a progress report

    International Nuclear Information System (INIS)

    Bossenberry, T.; Chollak, D.; Walker, G.; Evans, D. S.; Wilson, J. J.

    1997-01-01

    Updating a report presented at the 1996 annual meeting, these authors reported on an experiment on a 12 hectare site near Bonnyville in northeastern Alberta involving the addition of softwood sawdust, manure and inorganic fertilizers to the clay-rich stoney, glacial till parent material characterized by thin organic-poor cover and low nutrient composition. A nearby site of approximately the same size has been reclaimed using more conventional reclamation methods. The site with the added sawdust progressed slowly during spring and early summer, but more favorably with growing conditions in late 1996. It eventually resulted in better plant cover dominated by clover species with a late catching of grasses as understory vegetation. The conventionally treated site progressed more quickly with better production of both clovers and grasses. In 1997 the sawdust-added site accelerated with better and more consistent plant coverage and a better grass to clover ratio. The sawdust-amended topsoil profile remained stable, had good moisture retention and continued to be well drained and uncompacted. The overall assessment is that amended topsoils provide a short term physical and textural improvement to clay-rich soils and a longer term source of organic material. Therefore sawdust addition is particularly useful in remediating soils where topsoil quality is poor or insufficient for conventional reclamation

  1. Decomposition and carbon storage of hardwood and softwood branches in laboratory-scale landfills

    International Nuclear Information System (INIS)

    Wang, Xiaoming; Barlaz, Morton A.

    2016-01-01

    Tree branches are an important component of yard waste disposed in U.S. municipal solid waste (MSW) landfills. The objective of this study was to characterize the anaerobic biodegradability of hardwood (HW) and softwood (SW) branches under simulated but optimized landfill conditions by measuring methane (CH_4) yields, decay rates, the decomposition of cellulose, hemicellulose and organic carbon, as well as carbon storage factors (CSFs). Carbon conversions to CH_4 and CO_2 ranged from zero to 9.5% for SWs and 17.1 to 28.5% for HWs. When lipophilic or hydrophilic compounds present in some of the HW and SW samples were extracted, some samples showed increased biochemical methane potentials (BMPs). The average CH_4 yield, carbon conversion, and CSF measured here, 59.4 mL CH_4 g"−"1 dry material, 13.9%, and 0.39 g carbon stored g"−"1 dry material, respectively, represent reasonable values for use in greenhouse gas inventories in the absence of detailed wood type/species data for landfilled yard waste. - Highlights: • Characterized biodegradation of branches under simulated but optimized landfill conditions • Observed varied biodegradation between HW and SW branches with different diameters • Inhibitory extractives were observed on boughs or twigs of some branch species. • CH_4 yield and carbon storage factors presented for use in landfill related inventories.

  2. Comparison of dehumidification and heat and vent drying of hem-fir softwood

    Energy Technology Data Exchange (ETDEWEB)

    Mackay, J F.G.; Nielson, R W

    1988-03-01

    The objective of this project was to demonstrate the performance of dehumidifier kilns, compared to gas-fired, hot-air kilns in drying a commercial grade of softwood lumber. To accomplish this, drying tests were conducted with matched loads of lumber in a new test facility which was constructed to operate as a conventional heat and vent kiln or as a dehumidifier kiln. Comparisons were made of drying times, shrinkage and quality of dried product and total drying energy consumptions. Data from these tests were used in conjunction with capital, energy and other costs obtained from suppliers and operators of existing kilns to make economic comparisons between commercial-sized dehumidifier and heat and vent kilns. These comparisons were made on the basis of equivalent uniform annual costs. Dehumidification drying took about 20% longer and used about 50% of energy compared to heat and vent drying. Analysis of the test runs indicated that further improvements in the energy utilization efficiencies of dehumidifier kilns are feasible since one run indicated an energy consumption of only 36% of that in heat and vent drying. No differences in shrinkage or degrade were apparent. Economic comparisons for three sizes of kilns showed total drying costs by dehumidification to be less for a small-size kiln but more for medium- and large-size operations. Sensitivity analyses were performed to observe the effect of alternate energy prices, dehumidifier energy consumptions, dehumidifier drying times, building costs and degrade. 9 refs., 7 figs., 36 tabs.

  3. Hygromorphic characterization of softwood under high resolution X-ray tomography for hygrothermal simulation

    Science.gov (United States)

    El Hachem, Chady; Abahri, Kamilia; Vicente, Jérôme; Bennacer, Rachid; Belarbi, Rafik

    2018-03-01

    Because of their complex hygromorphic shape, microstructural study of wooden materials behavior has recently been the point of interest of researchers. The purpose of this study, in a first part, consists in characterizing by high resolution X-ray tomography the microstructural properties of spruce wood. In a second part, the subresulting geometrical parameters will be incorporated when evaluating the wooden hygrothermal transfers behavior. To do so, volume reconstructions of 3 Dimensional images (3D), obtained with a voxel size of 0.5 μm were achieved. The post-treatment of the corresponding volumes has given access to averages and standard deviations of lumens' diameters and cell walls' thicknesses. These results were performed for both early wood and latewood. Further, a segmentation approach for individualizing wood lumens was developed, which presents an important challenge in understanding localized physical properties. In this context, 3D heat and mass transfers within the real reconstructed geometries took place in order to highlight the effect of wood directions on the equivalent conductivity and moisture diffusion coefficients. Results confirm that the softwood cellular structure has a critical impact on the reliability of the studied physical parameters.

  4. Green liquor impregnation and Kraft pulping of South African Pinus Patula – “A practical approach to provide cost savings in a Kraft mill’s pulping operation”

    CSIR Research Space (South Africa)

    Johakimu, Jonas K

    2011-02-01

    Full Text Available . Singh J., Ragauskas A.R., Lucia L.A., (2002). ?Green Liquor Chip Pre- treatment as a Feasible Method for the Enhancement of Softwood Pulp Chemical Properties. Journal of wood Chemistry and Technology. 2: 173-181. 5. Gordon Broderick...

  5. Effects of Alkali Treatment and Polyisocyanate Crosslinking on the Mechanical Properties of Kraft Fiber-Reinforced Unsaturated Polyester Composites

    Directory of Open Access Journals (Sweden)

    Zhenhua Gao

    2014-08-01

    Full Text Available The effects of alkali treatment and polyisocyanate crosslinking on the mechanical properties of kraft fiber-reinforced UPE composites were investigated by means of tensile evaluation, SEM analysis, and XRD analysis. The results indicated that the alkali treatment decreased the tensile strength of the prepared composite before aging from 121 MPa to 97 MPa due to the decreased degree of crystallinity of the alkali-treated kraft fiber. Polyisocyanate crosslinking could apparently improve the mechanical properties and stability in terms of a 43% increase of non-aged tensile strength and 52% increase of hydrothermal-aged tensile strength compared with the controlled composite without crosslinking modification, which was attributable to the formation of strong chemical bonding between the interfaces of kraft fiber and polyester.

  6. Interactions of Kraft lignin and wheat gluten during biomaterial processing: evidence for the role of phenolic groups.

    Science.gov (United States)

    Kaewtatip, Kaewta; Menut, Paul; Auvergne, Remi; Tanrattanakul, Varaporn; Morel, Marie-Helene; Guilbert, Stephane

    2010-04-14

    The chemical interactions between Kraft lignin and wheat gluten under processing conditions were investigated by determining the extent of the protein network formation. To clarify the role of different chemical functions found in lignin, the effect of Kraft lignin was compared with that of an esterified lignin, in which hydroxyl groups had been suppressed by esterification, and with a series of simple aromatics and phenolic structures with different functionalities (conjugated double bonds, hydroxyl, carboxylic acid, and aldehyde). The protein solubility was determined by using the Kjeldahl method. The role of the hydroxyl function was assessed by the significantly lower effect of esterified lignin. The importance of the phenolic radical scavenging structure is evidenced by the effect of guaiacol, which results in a behavior similar to that of the Kraft lignin. In addition, the significant effect of conjugated double bonds on gluten reactivity, through nucleophilic addition, was demonstrated.

  7. Avaliação da madeira e da polpação kraft em clones de eucaliptos Wood evaluation and Kraft pulping in eucalypts clones

    Directory of Open Access Journals (Sweden)

    Adriana de Fátima Gomes Gouvêa

    2009-12-01

    Full Text Available A produção de celulose de baixo custo e alta qualidade requer madeira adequada e bem selecionada. A seleção de clones superiores tem sido realizada com base em critérios como densidade básica, rendimento gravimétrico da polpação e composição química da madeira, especialmente de celulose, hemiceluloses, extrativos e ligninas. O objetivo deste trabalho foi avaliar as características da madeira de Eucalyptus, por método destrutivo, e a produção de polpa celulósica kraft em seis clones. Utilizaram-se cinco árvores de cada clone, aos 3 anos de idade, plantadas em espaçamento 3,0 m x 3,3 m, nas regiões de Cocais, Guanhães, Rio Doce e Santa Bárbara, Estado de Minas Gerais. A densidade básica foi medida em discos extraídos a 1,3 m de altura do solo (DAP e em cavacos da árvore inteira (amostra composta. A composição química foi medida em amostras de serragem, retiradas no DAP. Os cozimentos foram efetuados a partir de cavacos da árvore inteira. Verificou-se que a densidade medida no DAP foi ligeiramente superior à medida nos cavacos da árvore toda. A composição química geral da madeira foi muito influenciada pelo tipo de clone, local de plantio e interação. Locais mais montanhosos produziram madeira com maior teor de celulose e menor de hemicelulose. A madeira do clone F da região de Santa Bárbara e Cocais apresentaram madeiras de qualidade inferior para produção de polpa celulósica. Os melhores rendimentos de polpação kraft foram alcançados com o clone B nas regiões de Guanhães e Santa Bárbara.Low cost and high quality cellulose production demands appropriate wood. The selection of superior clones has been done based on some criteria as basic density, gravimetric yield of pulping and wood chemical composition, especially of cellulose, hemicelluloses, extractive and lignin contents. This study aimed at evaluating the characteristics of the Eucalyptus wood, by destructive methods, and the Kraft pulping

  8. Kraft pulp bleaching with molybdenum activated acid peroxide (P{sub Mo} stage); Branqueamento de polpa celulosica kraft de eucalipto com peroxido acido ativado por molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, Marcos Sousa [Servico Nacional de Aprendizagem Industrial (SENAI), Lauro de Freitas, BA (Brazil). Dept. Regional da Bahia; Silva, Vanessa Lopes; Barros, Denise Pires de; Colodette, Jorge Luiz [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Florestal; Sacon, Vera Maria; Silva, Marcelo Rodrigues da [Votorantim Celulose e Papel, Jacarei, SP (Brazil)

    2009-07-01

    Optimum conditions to run the P{sub Mo} stage for bleaching eucalyptus kraft pulp were 90 deg C, pH 3.5, 2 h, 0.1 kg/t Mo and 5 kg/t H{sub 2}O{sub 2}. The P{sub Mo} stage efficiency increased with decreasing pH (1.5-5.5) and increasing temperature (75-90 deg C), time (2-4 h), and hydrogen peroxide (3-10 kg/t) and molybdenum concentration (0.1-0.4 kg/t). The implementation of the P{sub Mo} stage, as replacement for the A stage, decreased total active chlorine demand of the OAZDP sequence by 6 kg/t to reach 90% ISO, both in laboratory and mill scale. Such practice resulted in decreased bleaching chemical costs to produce fully bleached pulp of 90% ISO. (author)

  9. Energy efficiency improvement of a Kraft process through practical stack gases heat recovery

    International Nuclear Information System (INIS)

    Mostajeran Goortani, B.; Mateos-Espejel, E.; Moshkelani, M.; Paris, J.

    2011-01-01

    A process scheme for the optimal recovery of heat from stack gases considering energy and technical constraints has been developed and applied to an existing Kraft pulping mill. A system based on a closed loop recirculation of hot oil is used to recover the heat from stack gases and distribute it to the appropriate cold streams. The recovery of heat from stack gases is part of an overall optimization of the Kraft mill. Tools such as Pinch Analysis and exergy analysis are used to evaluate the process streams. The results indicate that 10.8 MW of heat from stack gases can be reused to heat process streams such as the deaerator water, hot water, drying filtrates, and black liquor. A simulation model of the recirculation loop has been developed to determine the specifications of the recovery system. The total heat exchanger surface area required by the system is 3460 m 2 , with a hot oil recirculation temperature of 137 o C. The anticipated total investment is $10.3 M, with a payback time of 1.8 years. - Highlights: → We developed a process design for recovering heat from stack gases in a Kraft mill. → The recovered heat is optimally distributed to the process cold streams. → Heat recovery system has a total surface area of 3500 m 2 without gases condensation. → A reduction of 7 percent in total process steam demand is anticipated. → A total investment of 10.3 M$ is needed with a payback time of less than two years

  10. PROCESS FOR THE PRODUCTION OF DISSOLVING PULP FROM TREMA ORIENTALIS (NALITA) BY PREHYDROLYSIS KRAFT AND SODA-ETHYLENEDIAMINE (EDA) PROCESS

    OpenAIRE

    M. A. Quaiyyum; A. Noori; Labooni Ahsan; M. Sarwar Jahan

    2008-01-01

    This paper presents a preliminary study for the production of dissolving pulp from Trema orientalis (Nalita). Water prehydrolysis kraft and soda-ethylenediamine (EDA) pulping for the production of dissolving pulp from T. orientalis was investigated. Prehydrolysis at 150 and 170 oC did not produce pulp with high α-cellulose content when using the kraft process. But addition of 0.25 % H2SO4 in prehydrolysis liquor increased the purity of the pulp with the sacrifice of pulp yield and viscosity. ...

  11. Utilización de Eucalyptus spp. Alternativas de plantaciones uruguayas para pulpa Kraft

    Directory of Open Access Journals (Sweden)

    Javier Doldán

    2011-05-01

    Full Text Available Las plantaciones de Eucalyptus globulus han mostrado desiguales tasas de crecimiento en diferentes regiones de Uruguay. Esto ha motivado la búsqueda de otros orígenes de semilla y especies para la producción de pulpa de celulosa. Propiedades papeleras de las pulpas blanqueadas (ECF de especies alternativas llevan a intuir que podrían ser atractivas para mercados de pulpa de fibra corta. En este trabajo se realiza un comparativo del E. grandis, E. dunnii, E. maidenii y E. globulus (procedencia de semilla “Jeeralang” con el E. globulus predominante en Uruguay. Se discute el potencial de estas maderas como base para una mezcla en cocción, basándose en el análisis de propiedades físicas (densidad aparente básica, propiedades pulpables (rendimiento, carga de álcali activo en cocción Kraft y consumo de madera y propiedades papeleras. En trabajos previos se han encontrado diferencias significativas entre el comportamiento pulpable del Eucalyptus globulus y Eucalyptus maidenii, sugiriendo que nosería recomendable mezclar estas especies. La misma conclusión se podría extender a las especies de Eucalyptus estudiadas. Sin embargo, teniendo en cuenta los similares requerimientos en las cargas de álcali activo, la mezcla entre especies alternativas podría ser aplicada.AbstractEucalyptus globulus plantations have shown different growth rates in different sites in Uruguay. This fact has triggered the search for other pulp wood species and seed provenance. Paper making properties of ECF bleached pulps of alternative speciessuggest that these species could be perfectly used as hardwood bleached pulp raw materials. This study intends to compare alternativeUruguayan pulpwood species E. grandis, E. dunnii, E. maidenii and “Jeeralang” a seed provenance of E. globulus to the E. globulus most widely cultivated in the country. Physical properties of wood (Basic Density, Kraft pulping performance (pulp yield, active alkali and wood consumption

  12. Precipitation and characterisation of lignin obtained from South African kraft mill black liquor

    CSIR Research Space (South Africa)

    Namane, M

    2014-07-01

    Full Text Available stream_source_info Namane_2014_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 637 Content-Encoding ISO-8859-1 stream_name Namane_2014_ABSTRACT.pdf.txt Content-Type text/plain; charset=ISO-8859-1 2014... International Conference on Chemical Thermodynamics and South African Institution of Chemical Engineering Conference, Durban, South Africa, 27 July - 1 August 2014 Precipitation and characterisation of lignin obtained from South African kraft mill black...

  13. The role of bound chlorine in the brightness reversion of bleached hardwood kraft pulp

    Directory of Open Access Journals (Sweden)

    Kátia Maria Morais Eiras

    2009-01-01

    Full Text Available Our previous paper showed fragmentary evidence that pulp brightness reversion may be negatively affected by its organically bound chlorine (OX content. A thorough investigation on eucalyptus kraft pulp led to the conclusion that OX increases reversion of certain pulps but this trend is not universal. Alkaline bleaching stages decrease reversion regardless of pulp OX content. Pulps bleached with high temperature chlorine dioxide revert less than those bleached with conventional chlorine dioxide in sequences ending with a chlorine dioxide stage but similarly in sequences ending with a final peroxide stage. The use of secondary condensate for pulp washing decreases reversion.

  14. Application of xylanases from Amazon Forest fungal species in bleaching of eucalyptus kraft pulps

    Directory of Open Access Journals (Sweden)

    Roseli Garcia Medeiros

    2007-03-01

    Full Text Available Crude xylanase preparations from Penicillium corylophilum, Aspergillus niger and Trichoderma longibrachiatum were used to treat Eucalyptus kraft pulp, prior to chlorine dioxide and alkaline bleaching sequences. The enzyme pretreatment improved brightness and delignification of non-delignified and oxygen-bleached samples of eucalyptus kraft pulp. Xylanase preparations from T. longibrachiatum and P. corylophilum were more effective to reduce pulp kappa number. A small reduction in viscosity was obtained when the oxygen-bleached pulp was treated with xylanase preparation from A. niger. For all enzyme samples, the best release of chromophoric material from the pulp was at 237 nm. The enzyme preparation from P. corylophilum was responsible for the highest release of reducing sugar at a dosage interval of 10-20 IU/g dry weight pulp. Scanning electron microscopy studies of oxygen-bleached pulp after xylanase treatment revealed morphological changes, including holes, cracks, filament forming and peeling.Amostras de xilanases de extratos brutos de Penicillium corylophilum, Aspergillus niger e Trichoderma longibrachiatum foram utilizadas no branqueamento de polpa kraft de eucalipto antes das seqüências alcalina e dióxido de cloro. O pré-tratamento enzimático melhorou a alvura e o processo de deslignificação de amostras de polpa kraft de eucalipto não-tratada e tratada com oxigênio. Amostras de xilanases de T. longibrachiatum e P. corylophilum foram mais efetivas na redução do número kappa da polpa. A polpa tratada com oxigênio sofreu uma pequena redução na sua viscosidade quando incubada com amostra de xilanase de A. niger. Para todas as amostras de xilanases, a maior liberação de cromóforos da polpa foi a 237 nm. A amostra de xilanase de P. corylophilum liberou maior quantidade de açúcar redutor da polpa, utilizando dosagem de 10-20 UI/g de peso seco da polpa. Estudos de microscopia eletrônica de varredura revelaram várias altera

  15. Jens Kraft og "De vilde Folk" (1760) - manden, forfatterskbet, værket

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2000-01-01

    had "set cultural development in motion." 7. Brief Account of the Savage Peoples from 1760, together with an address to the Academy of Young Noblemen at Sorø and Critical Letters for the Betterment of Taste, both from 1761, might be viewed as an interrelated group of sources bearing on one particular...... as religious concerns. 9. Kraft's reactions, as revealed by the contradictory tendencies in Brief Account of the Savage Peoples, testify to his unease with the paradoxes of modernity and its concomitant sense of value-loss. The dissertation is divided into three volumes.The first volume introduces the subject...

  16. A comprehensive program to develop correlations for physical properties of kraft black liquor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, A.L.; Zaman, A.A.

    1998-05-01

    The overall objective of the program was to develop correlations to predict physical properties within requirements of engineering precision from a knowledge of pulping conditions and of kraft black liquor composition, if possible. These correlations were to include those relating thermodynamic properties to pulping conditions and liquor composition. The basic premise upon which the research was based is the premise that black liquor behaves as a polymer solution. This premise has proven to be true, and has been used successfully in developing data reduction methods and in interpreting results. A three phase effort involving pulping, analysis of liquor composition, and measurement of liquor properties was conducted.

  17. Softwood forest thinning as a biomass source for ethanol production: A feasibility study for California

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Kiran L; Wooley, Robert J; Aden, Andrew; Nguyen, Quang A; Yancey, Mark A; Ferraro, Francis M [Colorado(United States)

    2000-07-01

    A plan has been put forth to strategically thin northern California forests to reduce fire danger and improve forest health. The resulting biomass residue, instead of being open burned, can be converted into ethanol that can be used as a fuel oxygenate or an octane enhancer. Economic potential for a biomass-to-ethanol facility using this softwood biomass was evaluated for two cases: Stand-alone and co-located. The co-located case refers to a specific site with an existing biomass power facility owned by Wheelabrator Environmental Systems Inc. near Martell, California. A two-stage dilute acid hydrolysis process is used for the production of ethanol from softwoods, and the residual lignin is used to generate steam and electricity. For a plant processing 800 dry tonnes per day of feedstock, the co-located case is an economically attractive concept. Total estimated capital investment is approximately $ 70 million for the co-located case. The resulting internal rate of return is about 24% using 25% equity financing. Hence, such a biomass-to-ethanol plant seems to be an appealing proposition for California, with ethanol replacing methyl tertiary-butyl ether, which is slated for a phaseout. [Spanish] Se ha desarrollado un plan para adelgazar estrategicamente los bosques del norte de California para reducir el peligro de incendio y mejorar la salud del bosque. El residuo resultante de biomasa en vez de ser quemado a la intemperie, puede ser convertido en etanol, el cual se puede utilizar como un combustible oxigenado o como un mejorador del octanaje. Se ha evaluado el potencial economico de una planta de conversion de biomasa a etanol utilizando la biomasa de las coniferas para dos opciones: Una planta independiente o una localizada junto a otra. El caso de la localizada una junto a otra se refiere a un lugar especifico con una instalacion ya existente de biomasa propiedad de Wheelabrator Environmental Systems Inc. cerca de Martell, California. Se utiliza un proceso de

  18. Determination of the most economical drying schedule and air velocity in softwood drying

    Energy Technology Data Exchange (ETDEWEB)

    Salin, J.G.

    2001-12-01

    Simulation models for conventional softwood drying have been available and have also been used by kiln operators for many years. For instance models for Scots pine and Norway spruce, dried at temperatures below about 80 deg C, are in use in Sweden, Finland and Norway. These models predict drying rates as a function of climate (schedule) and air velocity. The models thus give a direct basis for calculation of instantaneous energy demand for moisture evaporation and ventilation. There is further a direct relationship between the air velocity in the space between the board layers in the kiln stack and the electrical power demand by the circulation fans. Finally, the smaller energy consumption associated with heat losses through kiln walls and the accumulated heat in timber etc. can be estimated with sufficient accuracy. Instantaneous energy costs can thus be calculated for each part of a drying schedule. Capital costs associated with kiln investment and maintenance, personnel, insurance etc can be accounted for as an hourly cost, which is basically independent of whether timber is dried fast or slowly. A slow drying process thus accumulates more capital costs per m 3 timber. In this way it is possible to calculate the total instantaneous drying cost (Euro/m{sup 3}/h or Euro/m3/MC%) and the overall total cost (Euro or Euro/m{sup 3}). Some results obtained with a simulation model equipped with such a cost calculation are presented in the paper. A rapidly increasing drying cost is seen when the final MC is lowered. By minimising the instantaneous cost, an optimal drying schedule can be determined for a given fixed air velocity. Finally an optimal air velocity - constant or varying - can be found in the same way.

  19. ESTUDO DA ADIÇÃO DA LIGNINA KRAFT NAS PROPRIEDADES MECÂNICAS DOS BRIQUETES DE RESÍDUOS DA INDÚSTRIA MOVELEIRA

    Directory of Open Access Journals (Sweden)

    Adriana de Fátima Gomes Gouvêa

    2017-01-01

    Full Text Available In order to improve global effectiveness of energy production, a strategy is the model of bio-refineries in which all the components of biomass are totally used to produce a range of products with aggregated value. The kraft lignin is one of the products originated in the process of cellulose production that can be used in making densified products. The objective of this work was to evaluate the behavior of the addition of extracted kraft lignin of black kraft liquor in briquette manufactures with furniture industry waste, in the form of shavings and panel particles in different proportions. The briquettes were produced in laboratory briquetting, using the temperatures of 60, 75 and 90 o C. The pressing and cooling time was 5 minutes and pressure 68,9 x 10 5 N.m -2 (1000 PSI. The briquette quality was evaluated through determining the mechanical properties. The kraft lignin in adequate proportions and temperature showed advantages in the increase of resistance and the durability of the briquettes. The kraft lignin presented advantages such as agglutinative in briquette productions from wood waste at a pressing temperature of 90 o C with addition of 20% of kraft lignin, and at pressing temperatures of 60 and 75 o C at a proportion of addition of 40 and 60% of kraft lignin to wood waste, respectively.

  20. Direct heat transfer considerations for improving energy efficiency in pulp and paper Kraft mills

    Energy Technology Data Exchange (ETDEWEB)

    Savulescu, Luciana Elena; Alva-Argaez, Alberto [Natural Resources (Canada)

    2008-10-15

    The success of any process improvement study depends on the quality of the available data and the way in which the plant-specific characteristics are incorporated in the applied conceptual models; in the context of process integration studies these issues are directly related to the rules followed during the data extraction stage. Improving energy efficiency in a pulp and paper Kraft mill requires the identification of the most promising heat recovery network retrofit projects. In a retrofit analysis using pinch technology/process integration methods, only the process streams associated to the existing heat exchangers and some outlet streams (such as wastewater/effluent streams and vents) with high potential for heat recovery are usually included, while the energy exchanged through non-isothermal stream mixing (NIM) or direct heat transfer (DHT) is often assumed fixed and is not considered in the analysis. Relaxing this assumption requires extracting more data to represent the DHT design configuration that exists in the plant. However, different data extraction options can be considered to represent the DHT configuration depending on the associated process/operation constraints. This work describes a systematic procedure to extract and analyse the impacts of DHT on the overall energy efficiency of a Kraft process with a specific focus on mixing along the pulp line and in water tanks. (author)

  1. Direct heat transfer considerations for improving energy efficiency in pulp and paper Kraft mills

    International Nuclear Information System (INIS)

    Savulescu, Luciana Elena; Alva-Argaez, Alberto

    2008-01-01

    The success of any process improvement study depends on the quality of the available data and the way in which the plant-specific characteristics are incorporated in the applied conceptual models; in the context of process integration studies these issues are directly related to the rules followed during the data extraction stage. Improving energy efficiency in a pulp and paper Kraft mill requires the identification of the most promising heat recovery network retrofit projects. In a retrofit analysis using pinch technology/process integration methods, only the process streams associated to the existing heat exchangers and some outlet streams (such as wastewater/effluent streams and vents) with high potential for heat recovery are usually included, while the energy exchanged through non-isothermal stream mixing (NIM) or direct heat transfer (DHT) is often assumed fixed and is not considered in the analysis. Relaxing this assumption requires extracting more data to represent the DHT design configuration that exists in the plant. However, different data extraction options can be considered to represent the DHT configuration depending on the associated process/operation constraints. This work describes a systematic procedure to extract and analyse the impacts of DHT on the overall energy efficiency of a Kraft process with a specific focus on mixing along the pulp line and in water tanks

  2. Effect of Cellulases and Xylanases on Refining Process and Kraft Pulp Properties.

    Directory of Open Access Journals (Sweden)

    Kamila Przybysz Buzała

    Full Text Available Samples of bleached kraft pine cellulosic pulp, either treated with an enzyme preparation (a Thermomyces lanuginosus xylanase, an Aspergillus sp. cellulase, and a multienzyme preparation NS-22086 containing both these activities or untreated, were refined in a laboratory PFI mill. The treatment with cellulases contained in the last two preparations significantly improved the pulp's susceptibility to refining (the target freeness value of 30°SR was achieved in a significantly shorter time, increased water retention value (WRV and fines contents while the weighted average fiber length was significantly reduced. These changes of pulp parameters caused deterioration of paper strength properties. The treatment with the xylanase, which partially hydrolyzed xylan, small amounts of which are associated with cellulose fibers, only slightly loosened the structure of fibers. These subtle changes positively affected the susceptibility of the pulp to refining (refining energy was significantly reduced and improved the static strength properties of paper. Thus, the treatment of kraft pulps with xylanases may lead to substantial savings of refining energy without negative effects on paper characteristics.

  3. EFEITO DA QUALIDADE DA MADEIRA NO DESEMPENHO DA POLPAÇÃO KRAFT

    Directory of Open Access Journals (Sweden)

    Danila Morais de Carvalho

    2014-01-01

    Full Text Available The aim of this study was to evaluate the wood quality in the kraft pulping performance under two different pulping conditions at two delignification degrees based on results for the yield, brightness, viscosity, and k/ kappa corrected index. Eucalyptus wood (A, B, and C was analyzed about their physicochemical properties (basic and apparent density, insoluble and soluble lignin content, extractive content, ash and insoluble ash in hydrochloric acid and used for pulp production by modified kraft cooking, using two different pulping conditions: Condition I (PI - 16.5% effective alkali, 30% sulfidity, and 155º of cooking temperature; and Condition II (PII - 17.5% effective alkali, 32% sulfidity,and 147ºC cooking temperature. Both conditions were performed to kappa number 15.5 ± 0.5 and 18.0 ± 0.5. The following pulping parameters and pulp properties produced were evaluated: H factor, screened yield, viscosity, brightness, hexenuronic acid content, and the k/kappa corrected index. The A wood, which had lower extractives and lignin content in its constitution, as well as lower basic and apparent density when compared with B and C woods, showed good results for cooking parameters, especially the pulp produced at PII condition at kappa number 18.0 ± 0.5.Also, the A wood showed higher screened yield, brightness, and viscosity comparing to the other pulps produced. Those pulps produced with higher kappa number have lower k/kappa corrected index.

  4. Bio-based polyurethane prepared from Kraft lignin and modified castor oil

    Directory of Open Access Journals (Sweden)

    L. B. Tavares

    2016-11-01

    Full Text Available Current challenges highlight the need for polymer research using renewable natural sources as a substitute for petroleum-based polymers. The use of polyols obtained from renewable sources combined with the reuse of industrial residues such as lignin is an important agent in this process. Different compositions of polyurethane-type materials were prepared by combining technical Kraft lignin (TKL with castor oil (CO or modified castor oil (MCO1 and MCO2 to increase their reactivity towards diphenylmethane diisocyanate (MDI. The results indicate that lignin increases the glass transition temperature, the crosslinking density and improves the ultimate stress especially for those prepared from MCO2 and 30% lignin content from 8.2 MPa (lignin free to 23.5 MPa. Scanning electron microscopy (SEM micrographs of rupture surface after uniaxial tensile tests show ductile-to-brittle transition. The results show the possibility to develop polyurethane-type materials, varying technical grade Kraft lignin content, which cover a wide range of mechanical properties (from large elastic/low Young modulus to brittle/high Young modulus polyurethanes.

  5. The impact of kappa number composition on eucalyptus kraft pulp bleachability

    Directory of Open Access Journals (Sweden)

    M. M. Costa

    2007-03-01

    Full Text Available Consumption of chemicals during ECF bleaching of kraft pulp correlates reasonably well with kappa number, which measures with KMnO4 the total amount of oxidizable material in the pulp. However, the method does not distinguish between the oxidizable material in residual lignin and other structures susceptible to oxidation, such as hexenuronic acids (HexAs, extractives and carbonyl groups in the pulp. In this study an attempt is made to separate the main contributors to the kappa number in oxygen - delignified eucalyptus Kraft pulps and evaluate how these fractions behave during ECF bleaching using chlorine dioxide as the sole oxidant (DEDD sequence. Residual lignin and HexAs proved to be the main fractions contributing to the kappa number and chlorine dioxide consumption in ECF bleaching. Pulp bleachability with chlorine dioxide increases with increasing HexAs content of the pulp but chlorine dioxide per se does not react with HexAs. Reduction of pulp with sodium borohydride under conditions for removing carbonyl groups has no impact on bleachability. No correlation was found between the pulp of the extractive content and pulp bleachability. The removal of HexAs prior to ECF bleaching significantly decreases the formation of chlorinated organics in the pulp (OX and filtrates (AOX as well as of oxalic acids in the filtrates.

  6. Solar generation of hydrogen; Wasserstofferzeugung auf solarer Basis. Thermische Dissoziation des Wassers mit dem Licht-Kraft-Werk

    Energy Technology Data Exchange (ETDEWEB)

    Ziemba, G.

    2003-04-01

    Solar generation of hydrogen. The ''Licht-Kraft-Werke'' (LKW) is described. Due to this it will be possible to supply solid-state-lasers directly by sunlight. Supplied by lasers water should be split in a highest-temperature-reactor. An efficiency of more than 21% is supposed to be reached. (orig.)

  7. Influence of the chemical composition on the combustion properties of kraft black liquor; Mustalipeaen koostumuksen vaikutus lipeaen poltto-ominaisuuksiin

    Energy Technology Data Exchange (ETDEWEB)

    Alen, R; Siistonen, H; Malkavaara, P [Jyvaeskylae Univ. (Finland). Inst. of Chemistry

    1997-10-01

    The aim of this work is to study the combustion properties of kraft black liquors from modified cooking. Both the industrial and laboratory-made black liquors are included. In addition, changes in the combustion properties of the spent liquors obtained by mixing prior to combustion different chlorine-free bleach liquors with black liquor are studied. (orig.)

  8. Comparative study for hardwood and softwood forest biomass: chemical characterization, combustion phases and gas and particulate matter emissions.

    Science.gov (United States)

    Amaral, Simone Simões; de Carvalho, João Andrade; Costa, Maria Angélica Martins; Soares Neto, Turíbio Gomes; Dellani, Rafael; Leite, Luiz Henrique Scavacini

    2014-07-01

    Two different types of typical Brazilian forest biomass were burned in the laboratory in order to compare their combustion characteristics and pollutant emissions. Approximately 2 kg of Amazon biomass (hardwood) and 2 kg of Araucaria biomass (softwood) were burned. Gaseous emissions of CO2, CO, and NOx and particulate matter smaller than 2.5 μm (PM2.5) were evaluated in the flaming and smoldering combustion phases. Temperature, burn rate, modified combustion efficiency, emissions factor, and particle diameter and concentration were studied. A continuous analyzer was used to quantify gas concentrations. A DataRam4 and a Cascade Impactor were used to sample PM2.5. Araucaria biomass (softwood) had a lignin content of 34.9%, higher than the 23.3% of the Amazon biomass (hardwood). CO2 and CO emissions factors seem to be influenced by lignin content. Maximum concentrations of CO2, NOx and PM2.5 were observed in the flaming phase. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Biodegradation of softwood lignin and guaiacylglycerol-beta-guiacyl ether by extracellular enzyme in shiitake Lentinus edodes (Berk) Sing

    Energy Technology Data Exchange (ETDEWEB)

    Oki, T.; Senba, Y.; Ishikawa, H.

    1982-01-01

    In order to explain the biodegradation of softwood lignin by shiitake (Lentinus edodes Berk. Sing.), akamatsu (Pinus densiflora Sekb. and Zucc.) dioxane lignin (NDL) and guaicylglycerol-beta-guaiacyl ether (I) were degraded by extracellular enzyme from the NDL-contained potato and malt extracts cultures of shiitake TMI-563 and 655 at 25 degrees C for a prolonged period. The main results on the basis of a functional group analysis and gel-filtration of NDL before and after the enzymatic degradation showed that the degraded DL had a higher content of phenolic OH groups than sound lignin, whereas the methoxyl or aromatic aldehyde-yielding group content was lower in the degraded lignin. The main degradation products formed from I in a crude enzyme solution were guaiacol, guaiacylglycerol, guaiacylglycol-beta-guaiacyl ether (II), and guaiacoxyacetoguaiacone (III), although the polymer was formed at pH 4.0, which is the optimum pH of peroxidase and laccase. It also was clarified that the oxidative polymerization of NDL and I occurred preferably in a crude enzyme solution at pH 4.0, and that these compounds were degraded to lower molecular fragments at pH 6.8 under the same conditions. From the above results, it is suggested that softwood lignin is more effectively degraded by the other enzyme than polyphenoloxidase, such as laccase and peroxidase, in a crude enzyme solution of L. edodes. (Refs. 9).

  10. Changes in the DRIFT Spectra of Softwood Materials Irradiated by UV-laser as a Function of Energy

    Directory of Open Access Journals (Sweden)

    BARTA, Edit

    2005-01-01

    Full Text Available We investigated energy dependence of the effect of UV-laser irradiation on the DRIFT spectra of softwood samples. Changes in the spectra of softwoods have been studied with 248.5 nm wavelength of UV-laser radiation. To monitor the energy dependence, different number of laser impulses were directed towards the sample’s surface. The dependence on energy of different bands can be listed into four groups. Broad absorption bands, which belong to the same chemical groups located at various positions, do not show consistent changes due to the absorption of different energy dozes. The intensity of OH bands for the treated samples can be higher or lower depending on the amount of radiation energy. In the CHn and in the band of non-conjugated carbonyl groups only absorption increase can be observed. Bands resulting from only one chemical component, and containing no other absorption maxima around them, uniformly decreased. The regions where the band of a chemical component lies next to another one, showed no consistent changes during the irradiation. The initial decrease was followed by increase.

  11. Structural characterization of Kraft lignins from different spent cooking liquors by 1D and 2D Nuclear Magnetic Resonance spectroscopy

    International Nuclear Information System (INIS)

    Fernández-Costas, C.; Gouveia, S.; Sanromán, M.A.; Moldes, D.

    2014-01-01

    Three Kraft lignins isolated from black liquors of several paper pulp mills of the North of Spain and Portugal were structurally characterized by using monodimensional ( 1 H and 13 C) and bidimensional Nuclear Magnetic Resonance (NMR) spectrometry. From the latter, 13 C– 1 H heteronuclear single quantum correlation (HSQC) and heteronuclear multiple bond correlation (HMBC) were employed. Lignins from black liquors are usually burned for power generation. Nevertheless, they could become high value added products within a biorefinery context. In that case, a good understanding of their structure is a prior step to transform them. From all the NMR techniques studied, HSQC has risen as the most powerful tool in lignin characterization. Kraft cooking conditions and the type of wood seem to be the main factors that determine the differences observed in the lignins. All the samples have shown an important decrease in the number of β–O–4′ linkages, due to the Kraft process, and resinol has become the most resistant linkage to the process. Moreover, all samples seem to be mainly linked to a one polysaccharide: xylan. Several parameters like S/G ratio, portion of phenolic and aliphatic hydroxyls, amount of aromatic protons and other structural aspects were also estimated. - Highlights: • Lignins from three Kraft spent liquors were obtained by acid precipitation. • Structural characterization of the dissolved lignins was performed by NMR. • Wood source and pulping conditions determine the lignin characteristics. • Kraft process implies cleavage of β–O–4 linkages and survival of resinol linkages. • Comparison of the samples would aid decisions on its future revalorization

  12. Ethanol from softwood. Process development based on steam pretreatment and SSF

    Energy Technology Data Exchange (ETDEWEB)

    Stenberg, Kerstin

    1999-05-01

    Fuel ethanol can be produced from lignocellulosics by the enzymatic hydrolysis process, which consists of a pretreatment step prior to hydrolysis, followed by fermentation and finally refining. This thesis deals with the development of the enzymatic process using softwood as raw material. The focus has not only been on how to obtain high yields, but also on how to solve problems, which can arise in an industrial process, such as inhibition and contamination. The pretreatment step was evaluated using steam-pretreatment and impregnation with an acid catalyst, either SO{sub 2} or H{sub 2}SO{sub 4}. Both impregnation methods resulted in approximately the same yield, 65% of the theoretical of fermentable sugars, i.e. glucose and mannose, after enzymatic hydrolysis. However, impregnation with SO{sub 2}, resulted in higher ethanol productivity and yield in the fermentation. Simultaneous saccharification and fermentation (SSF) was investigated using various substrate and cellulase concentrations. An overall ethanol yield of 70% of the theoretical was obtained using the whole slurry from the pretreatment step at an insoluble dry weight content of 5%, which was shown to be optimal. SSF resulted in both higher productivity and higher ethanol yield than in separate hydrolysis and fermentation, but proved to be more sensitive to infection by lactic aid bacteria. More complex process integration, in the form of recirculation of process streams, which is desirable in an industrial process, was investigated using bench-scale equipment. A reduction in the fresh-water demand of 50%, from 3 kg/kg dry raw material to 1.5 kg/kg dry raw material, was found to be possible without any negative effects on either hydrolysis or fermentation. A techno-economic evaluation of different process configurations in a process applying SSF was also performed. It was found that the ethanol production cost could be reduced by 20% by internal energy integration and by another 15% by recirculation to the

  13. Life cycle greenhouse gases and non-renewable energy benefits of kraft black liquor recovery

    International Nuclear Information System (INIS)

    Gaudreault, Caroline; Malmberg, Barry; Upton, Brad; Miner, Reid

    2012-01-01

    The life cycle greenhouse gas (GHG) and fossil fuel benefits of black liquor recovery are analyzed. These benefits are due to the production of energy that can be used in the pulping process or sold, and the recovery of the pulping chemicals that would otherwise need to be produced from other resources. The fossil GHG emissions and non-renewable energy consumption of using black liquor in the kraft recovery system are approximately 90% lower than those for a comparable fossil fuel-based system. Across all scenarios, the systems relying on black liquor solids achieve a median reduction of approximately 140 kg CO 2 eq./GJ of energy produced, compared to the systems relying on fossil fuels to provide the same energy and pulping chemical production functions. The benefits attributable to the recovery of pulping chemicals vary from 44% to 75% of the total benefit. Applied to the total production of kraft pulp in the U.S., the avoided emissions are equivalent to the total Scopes 1 and 2 emissions from the entire U.S. forest products industry. These results do not depend on the accounting method for biogenic carbon (because biogenic CO 2 emissions are the same for the systems compared) and the results are valid across a range of assumptions about the displaced fossil fuel, the GHG-intensity of the electricity grid, the fossil fuels used in the lime kiln, and the level of cogeneration at pulp and paper mills. The benefits occur without affecting the amount of wood harvested or the amount of chemical pulp produced. -- Highlights: ► Black liquor, a by-product of kraft pulping, represents about half of the energy used in the paper industry. ► The greenhouse gases (GHG) benefits of black liquor recovery compared to an equivalent fossil fuel system were analyzed. ► The GHG emissions of the black liquor system are approximately 90% lower than those for the fossil fuel system. ► The benefits from the recovery of the chemicals vary from 44% to 75% of the total benefit.

  14. Comment on 'evaluation of dechlorination mechanisms during anaerobic fermentation of blached kraft mill effluent by W.J. Parker, E.R. Hall and G.J. Farquhar'

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    Comment on "Evaluation of dechlorination mechanisms during anaerobic fermentation of bleached kraft mill effluent", is put forth. The data reproduced in Table 1 does not seem to be authentic as the method of preprationo of the chlorinated organic...

  15. Combined heat and power with the use of fuel cells; Kraft-Waerme-Kopplung mit Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Arends, G; Lehmann, M [Deutsches Brennstoffzellenforum e.V., Bonn (Germany)

    1997-12-01

    Fuel cell systems have the potential to cause increased efficiency, cleanness and decentralization in all areas of energy consumption. This article describes technical characteristics and current development status of the different fuel cell types with a view to their use as cogeneration facilities. The following types of fuel cell are examined: - Proton Exchange Membrane Fuel Cell (PEMFC), - Phosphoric Acid Fuel Cell (PAFC), - Molten Carbonate Fuel Cell (MCFC), - Solid Oxide Fuel Cell (SOFC). (orig.) [Deutsch] Brennstoffzellensysteme haben das Potential, in allen Sektoren des Endenergieverbrauchs wesentliche Verbesserungen bezueglich Effizienz, Sauberkeit und Dezentralisierung zu bewirken. In dem folgenden Aufsatz werden die technischen Eigenschaften und der aktuelle Entwicklungsstand verschiedener Brennstoffzellentypen im Hinblick auf ihren Einsatz in der Kraft-Waerme-Kopplung beschrieben. Ein Ueberblick ueber neueste Demonstrationsprojekte informiert ueber den Stand der Technik. Konkrete - wenngleich unsichere - Angaben zur Wirtschaftlichkeit projektierter Brennstoffzellensystme ergeben, dass die genannten Vorteile der Brennstoffzellentechnologie moeglicherweise schon um die Jahrhundertwende auch oekonomisch interessant werden. (orig.)

  16. Fractionation and cellulase treatment for enhancing the properties of kraft-based dissolving pulp.

    Science.gov (United States)

    Duan, Chao; Wang, Xinqi; Zhang, YanLing; Xu, Yongjian; Ni, Yonghao

    2017-01-01

    The aim of this study was to investigate a combined process involving pulp fractionation and cellulase treatment of each fraction for improving the molecular weight distribution (MWD) and reactivity of a kraft-based dissolving pulp. Three pulp fractions, namely long-fiber, mid-fiber and short-fiber fractions (LF, MF and SF, respectively), were used as the substrates. The results showed that the SF had the highest accessibility, lowest viscosity, and highest cellulase adsorption capacity, while the opposite was true for the LF. At a given viscosity, the combined process led to a lower polydispersity index (3.71 vs 4.98) and a higher Fock reactivity (85.6% vs 76.3%), in comparison to the conventional single-stage cellulase treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Process for purification of waste water produced by a Kraft process pulp and paper mill

    Science.gov (United States)

    Humphrey, M. F. (Inventor)

    1979-01-01

    The water from paper and pulp wastes obtained from a mill using the Kraft process is purified by precipitating lignins and lignin derivatives from the waste stream with quaternary ammonium compounds, removing other impurities by activated carbon produced from the cellulosic components of the water, and then separating the water from the precipitate and solids. The activated carbon also acts as an aid to the separation of the water and solids. If recovery of lignins is also desired, then the precipitate containing the lignins and quaternary ammonium compounds is dissolved in methanol. Upon acidification, the lignin is precipitated from the solution. The methanol and quaternary ammonium compound are recovered for reuse from the remainder.

  18. The effect of temperature on the catalytic conversion of Kraft lignin using near-critical water

    DEFF Research Database (Denmark)

    Nguyen, Thi Dieu Huyen; Maschietti, Marco; Åmand, Lars-Erik

    2014-01-01

    The catalytic conversion of suspended LignoBoost Kraft lignin was performed in near-critical water using ZrO2/K2CO3 as the catalytic system and phenol as the co-solvent and char suppressing agent. The reaction temperature was varied from 290 to 370 C and its effect on the process was investigated...... in a continuous flow (1 kg/h). The yields of water-soluble organics (WSO), bio-oil and char (dry lignin basis) were in the ranges of 5–11%, 69–87% and 16–22%, respectively. The bio-oil, being partially deoxygenated, exhibited higher carbon content and heat value, but lower sulphur content than lignin. The main 1...

  19. Impact of burning oil as auxiliary fuel in kraft recovery furnaces upon SO2 emissions

    International Nuclear Information System (INIS)

    Someshwar, A.V.; Caron, A.L.; Pinkerton, J.E.

    1990-01-01

    The relationship between burning medium sulfur oil as auxiliary fuel in kraft recovery furnaces and SO 2 emissions was examined. Analysis of long-term CEMS SO 2 data from four furnaces shows no increase in SO 2 emissions as a result of oil burning. The results of field tests conducted at four furnaces while co-firing oil with liquor (up to 34% of total heat input) show that (1) average SO 2 emissions during the oil firing period either decreased or remained unchanged; (2) the overall sulfur retention within the furnace remained consistently high (more than 90%) with increasing levels of oil burning; (3) apportioning stack SO 2 emissions between those derived from oil and black liquor was infeasible. The results indicate that the same alkali fume generation processes that lead to the efficient capture of SO 2 resulting from black liquor combustion may be responsible for the capture of SO 2 resulting from sulfur-containing oil combustion

  20. Effects of Kraft Mill effluent on the sexuality of fishes: An environmental early warning

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.P.; Bortone, S.A.

    1992-01-01

    Arrhenoid or masculinized female fish species of the live-bearing family, Poeciliidae, have been observed for over thirteen years in specific southern streams which receive waste effluents from pulping mills. The complex mixture of organic compounds in kraft mill effluent (KME) has inhibited specific identification of causal agent(s). However, microbially degraded phytosterols (e.g. sitosterol or stigmastanol) in experimental exposures induce the same intersexual states that characterize affected female poeciliids sampled from KME streams. KME-polluted streams often exhibit a drastic reduction of fish species diversity and degrees of physiological stress, all of which suggests reduced reproduction in surviving forms. A potential ontogenetic or developmental response is demonstrated in American eels captured in one of these streams as well. The authors examine available information, including laboratory and experimental field exposures, and suggest directions for additional research as well as the need for environmental concern.

  1. Caffeic acid production by simultaneous saccharification and fermentation of kraft pulp using recombinant Escherichia coli.

    Science.gov (United States)

    Kawaguchi, Hideo; Katsuyama, Yohei; Danyao, Du; Kahar, Prihardi; Nakamura-Tsuruta, Sachiko; Teramura, Hiroshi; Wakai, Keiko; Yoshihara, Kumiko; Minami, Hiromichi; Ogino, Chiaki; Ohnishi, Yasuo; Kondo, Ahikiko

    2017-07-01

    Caffeic acid (3,4-dihydroxycinnamic acid) serves as a building block for thermoplastics and a precursor for biologically active compounds and was recently produced from glucose by microbial fermentation. To produce caffeic acid from inedible cellulose, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) reactions were compared using kraft pulp as lignocellulosic feedstock. Here, a tyrosine-overproducing Escherichia coli strain was metabolically engineered to produce caffeic acid from glucose by introducing the genes encoding a 4-hydroxyphenyllactate 3-hydroxylase (hpaBC) from Pseudomonas aeruginosa and tyrosine ammonia lyase (fevV) from Streptomyces sp. WK-5344. Using the resulting recombinant strain, the maximum yield of caffeic acid in SSF (233 mg/L) far exceeded that by SHF (37.9 mg/L). In the SSF with low cellulase loads (≤2.5 filter paper unit/g glucan), caffeic acid production was markedly increased, while almost no glucose accumulation was detected, indicating that the E. coli cells experienced glucose limitation in this culture condition. Caffeic acid yield was also negatively correlated with the glucose concentration in the fermentation medium. In SHF, the formation of by-product acetate and the accumulation of potential fermentation inhibitors increased significantly with kraft pulp hydrolysate than filter paper hydrolysate. The combination of these inhibitors had synergistic effects on caffeic acid fermentation at low concentrations. With lower loads of cellulase in SSF, less potential fermentation inhibitors (furfural, 5-hydroxymethyfurfural, and 4-hydroxylbenzoic acid) accumulated in the medium. These observations suggest that glucose limitation in SSF is crucial for improving caffeic acid yield, owing to reduced by-product formation and fermentation inhibitor accumulation.

  2. Effects of black liquor shocks on activated sludge treatment of bleached kraft pulp mill wastewater.

    Science.gov (United States)

    Morales, Gabriela; Pesante, Silvana; Vidal, Gladys

    2015-01-01

    Kraft pulp mills use activated sludge systems to remove organic matter from effluents. Process streams may appear as toxic spills in treatment plant effluents, such as black liquor, which is toxic to microorganisms of the activated sludge. The present study evaluates the effects of black liquor shocks in activated sludge systems. Four black liquor shocks from 883 to 3,225 mg chemical oxygen demand-COD L(-1) were applied during 24 hours in a continuously operating lab-scale activated sludge system. Removal efficiencies of COD, color and specific compounds were determined. Moreover, specific oxygen uptake rate (SOUR), sludge volumetric index (SVI) and indicator microorganisms were evaluated. Results show that the addition of black liquor caused an increase in COD removal (76-67%) immediately post shock; followed two days later by a decrease (-19-50%). On the other hand, SOUR ranged between 0.152 and 0.336 mgO2 g(-1) volatile suspended solids-VSS• min(-1) during shocks, but the initial value was reestablished at hour 24. When the COD concentration of the shock was higher than 1,014 mg/L, the abundance of stalked ciliates and rotifers dropped. Finally, no changes in SVI were observed, with values remaining in the range 65.8-40.2 mL g(-1) total suspended solids-TSS during the entire operating process. Based on the results, the principal conclusion is that the activated sludge system with the biomass adapted to the kraft pulp effluent could resist a black liquor shock with 3,225 mgCOD L(-1) of concentration during 24 h, under this study's conditions.

  3. Improved Materials for Use as Components in Kraft Black Liquor Recovery Boilers; TOPICAL

    International Nuclear Information System (INIS)

    Keiser, J.R.

    2001-01-01

    This Cooperative Research and Development Agreement (CRADA) was undertaken to evaluate current and improved materials and materials processing conditions for use as components in kraft black liquor recovery boilers and other unit processes. The main areas addressed were: (1) Improved Black Liquor Nozzles, (2) Weld Overlay of Composite Floor Tubes, and (3) Materials for Lime Kilns. Iron aluminide was evaluated as an alternate material for the nozzles used to inject an aqueous solution known as black liquor into recovery boilers as well for the uncooled lining in the ports used for the nozzles. Although iron aluminide is known to have much better sulfidation resistance in gases than low alloy and stainless steels, it did not perform adequately in the environment where it came into contact with molten carbonate, sulfide and sulfate salts. Weld overlaying carbon steel tubes with a layer of stainless weld metal was a proposed method of extending the life of recovery boiler floor tubes that have experienced considerable fireside corrosion. After exposure under service conditions, sections of weld overlaid floor tubes were removed from a boiler floor and examined metallographically. Examination results indicated satisfactory performance of the tubes. Refractory-lined lime kilns are a critical component of the recovery process in kraft pulp mills, and the integrity of the lining is essential to the successful operation of the kiln. A modeling study was performed to determine the cause of, and possible solutions for, the repeated loss of the refractory lining from the cooled end of a particular kiln. The evaluation showed that the temperature, the brick shape and the coefficient of friction between the bricks were the most important parameters influencing the behavior of the refractory lining

  4. Oil and gas activities in northern Norway. Summary; KonKraft rapport 6

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    KonKraft report 6 deals with oil and gas operations on the Norwegian continental shelf (NCS) from Nordland county and northwards. It aims to contribute to a broad factual base for decision processes related to opening new exploration areas in these waters. The Norwegian petroleum sector employs about 250 000 people directly and indirectly. It accounts for a third of government revenues, and 90 per cent of its profits accrue to the state. NOK 119 billion of the central government budget in 2009 comes directly from oil and gas revenues. These funds finance roads, nursery schools, hospitals and the Norwegian welfare state. In addition, they safeguard future pensions. This industry is at a crossroads today. Oil production has dropped by 30 per cent since 2000. Recent forecasts from the Norwegian Petroleum Directorate show that it may be reduced by 50 per cent from its peak by 2013. Overall oil and gas output is expected to begin falling from the middle of the next decade. To slow this decline in output and revenues, the oil companies need access to new and attractive exploration acreage. Half the production expected by the government in 2030 relates to resources which have yet to be proven. Opening further areas of the NCS to petroleum activities would contribute to maintaining substantial investment and revenues for the community, and to continuing the development of industry in the northernmost parts of the country. The report reviews unopened areas along the Norwegian coast from the Helgeland region and north-eastwards to the Russian border. Nordland VI and VII plus Troms II are regarded by the petroleum industry as the most promising regions for big discoveries which could slow the production decline. The KonKraft 2 report concerning production development on the NCS estimates remaining resources in these three areas at 3.4 billion barrels of oil equivalent (boe). (Author)

  5. Oxidative pyrolysis of kraft lignin in a bubbling fluidized bed reactor with air

    International Nuclear Information System (INIS)

    Li, Dongbing; Briens, Cedric; Berruti, Franco

    2015-01-01

    Fast pyrolysis of kraft lignin with partial (air) oxidation was studied in a bubbling fluidized bed reactor at reaction temperatures of 773 and 823 K. The bio-oil vapors were fractionated using a series of three condensers maintained at desired temperatures, providing a dry bio-oil with less than 1% water and over 96% of the total bio-oil energy. Oxygen feed was varied to study its effect on yield, composition, and energy recovery in the gas, char and oil products. The addition of oxygen to the pyrolysis process increased the production of gases such as CO and CO 2 . It also changed the dry bio-oil properties, reducing its heating value, increasing its oxygen content, reducing its average molecular weight and tar concentration, while increasing its phenolics concentration. The lower reaction temperature of 773 K was preferred for both dry bio-oil yield and quality. Autothermal operation of the pyrolysis process was achieved with an oxygen feed of 72 or 54 g per kg of biomass at the reaction temperatures of 773 and 823 K, respectively. Autothermal operation reduced both yield and total energy content of the dry bio-oil, with relative reductions of 24 and 20% for the yield, 28 and 23% for the energy content, at 773 and 823 K. - Highlights: • Autothermal pyrolysis of Kraft lignin is possible with introduction of air. • Under autothermal conditions, 24% of the dry bio-oil chemicals are lost at 773 K. • Partial oxidation helps produce more simple phenols and less pyrolytic lignin. • Bio-oil from lignin pyrolysis has a very high phenolics concentration

  6. Influence of bleaching technologies on the aerobic biodegradability of effluents from Eucalyptus kraft pulps factories

    Directory of Open Access Journals (Sweden)

    Gladys Vidal

    1999-01-01

    Full Text Available Aerobic biodegradability of effluents from different Eucalyptus kraft pulp bleaching processes was studied. Bleaching effluents were obtained from: i Chlorine Bleaching (CB processes, with partial substitution of chlorine by chlorine dioxide and ii Total Chlorine Free (TCF processes. The overall biodegradability, in terms of Chemical Oxygen Demand (COD was higher for TCF effluents (96-98% than for CB ones (82-93%. Taking into account the higher organic load of CB effluents, this fact implied a much higher residual COD for them (100-180 mg/L than for TCF effluents (10-30 mg/L. Furthermore, a refractory fraction of molecular weight higher than 43,000 Da was found in CB effluent, which implied the necessity of a further specific treatment. The toxicity was completely removed after the biological treatmentA biodegradabilidade aerobica das águas residuais provenientes de diferentes procesos de branqueos de pulpa kraft foi estudada. Os efluentes são gerados no branqueo com cloro ou parcialmente sustituido com dioxido de cloro (CB ou bem em processos livres do cloro (TCF. A biodegradabilidade, quantificada como DQO foi maior para as águas do processo CB. Tendo em conta o elevado conteúdo orgânico do efluente CB obteinse uma maior concentraç&ão do DQO final neste efluente comparado com o efluente TCF. Uma fracçao recalcitrante maior a 43,000 Da no effluente BC foi encontrada, isto significa um tratamento adicional específico para sua eliminaçã o. A toxicidade foi totalmente eliminada despois do tratamento aeração.

  7. Efeito do teor de lignina da madeira de Eucalyptus globulus Labill. no desempenho da polpação kraft

    Directory of Open Access Journals (Sweden)

    Gabriel Valim Cardoso

    2011-01-01

    Full Text Available In this research, it was analyzed the lignin content effect of Eucalyptus globulus Labill. wood in kraft pulping optimization. Seventy-two laboratory cooking were made with wood chips obtained from six Eucalyptus globulus trees selected from a group of 50 trees. The wood chips from three trees with the lowest lignin content, with average 20.53%, were mixed proportionally based on the tree weights, obtaining the sample of low lignin content wood. The same was made to obtain the sample for wood chips with the highest lignin content, with average 23.02%. The two lignin levels were statistically different. The two wood samples had basic densities statistically not different. Using three maximum temperatures levels (160, 165 and 170ºC, and three active alkali charged (17, 18.5 and 20%, the wood chips were converted to kraft pulps. The pulps were then characterized to analyze the influence of the distinct treatments employed in the cooking on their properties. The effect of the cooking conditions was expressed by mathematical models in order to determine the optimum points for each of the evaluated properties. The optimization process indicated maximum temperature of 168ºC, and active alkali of 19%, for maximum kraft pulping yield to achieve kappa number 18; this result was for woods with low lignin content. For woods containing the high lignin content, the optimization showed maximum cooking temperature of 169ºC and active alkali of 19% for kappa number of 18. The average reduction of 2.49% in wood lignin content resulted a correspondent gain of 2.2% in the kraft yield (o.d. basis and a reduction on the active alkali charge of 1.2% (o.d. basis to achieve kappa numbers from 16 to 19, preserving pulp properties. If the option is to work with kappa number 19 instead of 16, the gain in kraft yield is approximately 2%. Therefore, when working with low lignin content wood and kappa number 19 instead of 16, a substantial gain of approximately 4.2% is

  8. Characterization of solid wastes from kraft pulp industry for ceramic materials development purposes; Caracterizacao de residuos solidos da industria de celulose tipo kraft visando sua aplicacao no desenvolvimento de materiais ceramicos

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, L.R.; Francisco, M.A.C.O.; Sagrillo, V.P.D.; Louzada, D.M.; Entringer, J.M.S. [Instituto Federal do Espirito Santo (IFES), Vitoria, ES (Brazil)

    2016-07-01

    The Kraft pulp industry generates a large amount of solid wastes. Due this large quantity, the target of this study is characterize inorganic solid wastes, dregs, grits and lime mud, from the step of reagents recovery of Kraft process, aiming evaluate the potentiality of their use as alternative raw material on development of ceramic materials. Initially, the wastes were dried and ground, then they were subjected to the following characterization techniques: pH analysis, particle size analysis, X ray fluorescence, X ray diffraction, differential thermal analysis and thermogravimetric analysis and scanning electron microscopy. According to the results, it may be concluded that these wastes could be used as raw material in production of red ceramic and luting materials. (author)

  9. EFFECT OF THE REACTION CONDITIONS OVER THE YIELD AND PROPERTIES OF METHYLCELLULOSE OBTAINED FROM PINUS RADIATA KRAFT BLEACHED CELLULOSE

    OpenAIRE

    TAPIA, C.; SAPAG-HAGAR, J.; ANDRADE, C.T.; HASSÓN, J.; VALENZUELA, F.; BASUALTO, C.

    2002-01-01

    Kraft bleached cellulose from Pinus radiata was submitted to methylation reactions in heterogeneous media. After activation with 29% (w/w) NaOH solution, methylation reactions were carried out both with dimethyl sulfate (DMS) and methyl iodide (MI). The effects of the pressing ratio, reaction time and type of methylation agent were studied. The better yields were obtained with dimethylsulphate and the pressing ratio and reaction time were not signficant over the yield. Methylcellulose (MC) of...

  10. Inter-laboratory comparisons of hexenuronic acid measurements in kraft eucalyptus pulps using a UV-Vis spectroscopic method

    Science.gov (United States)

    J.Y. Zhu; H.F Zhou; Chai X.S.; Donna Johannes; Richard Pope; Cristina Valls; M. Blanca Roncero

    2014-01-01

    An inter-laboratory comparison of a UV-Vis spectroscopic method (TAPPI T 282 om-13 “Hexeneuronic acid content of chemical pulp”) for hexeneuronic acid measurements was conducted using three eucalyptus kraft pulps. The pulp samples were produced in a laboratory at kappa numbers of approximately 14, 20, and 35. The hexeneuronic acid contents of the three pulps were...

  11. Ecotoxicological studies with newly hatched larvae of Concholepas concholepas (Mollusca, Gastropoda): bioassay with secondary-treated kraft pulp mill effluents.

    Science.gov (United States)

    Manríquez, Patricio H; Llanos-Rivera, Alejandra; Galaz, Sylvana; Camaño, Andrés

    2013-12-01

    The Chilean abalone or "loco" (Concholepas concholepas, Bruguière 1789) represent the most economically important marine recourse exploited from inner inshore Management and Exploitation Areas for Benthic Resources along the Chilean coast. In this study, newly-hatched larvae of C. concholepas were investigated as a potential model species for marine ecotoxicological studies. The study developed a behavioral standard protocol for assessing the impact that kraft pulp mill effluents after secondary treatment have on C. concholepas larvae. Under controlled laboratory conditions, newly-hatched larvae were exposed to a series of different concentrations of kraft pulp mill effluents with secondary treatment (Pinus spp. and Eucalyptus spp.), potassium dichromate as standard reference toxicant and effluent-free control conditions. Regardless of the type of effluent the results indicated that diluted kraft pulp effluent with secondary treatment had reduced effect on larval survival. Low larval survivals were only recorded when they were exposed to high concentrations of the reference toxicant. This suggests that C. concholepas larval bioassay is a simple method for monitoring the effects of kraft pulp mill effluents with secondary treatment discharged into the sea. The results indicated that dilution of ca. 1% of the effluent with an elemental chlorine free (ECF) secondary treatment is appropriate for achieving low larval mortalities, such as those obtained under control conditions with filtered seawater, and to minimize their impact on early ontogenetic stages of marine invertebrates such as newly-hatched larvae of C. concholepas. The methodological aspects of toxicological testing and behavioral responses described here with newly-hatched larvae of C. concholepas can be used to evaluate in the future the potential effects of other stressful conditions as other pollutants or changes in seawater pH associated with ocean acidification. © 2013 Elsevier Inc. All rights

  12. Performance of Side-Streams from Eucalyptus Processing as Sources of Polysaccharides and Lignins by Kraft Delignification

    OpenAIRE

    Paula C. R. Pinto; Cátia Oliveira; Carina Costa; Alírio Rodrigues

    2016-01-01

    The performance of bark, branches, sawdust, forest biomass, and short-rotation eucalyptus in kraft delignification to produce polysaccharides and lignin is reported and discussed. A positive correlation was found between pulping severity required for delignification and lignin reactivity. Among all, branches feedstock is the best source of polysaccharides due to the high pulp yield (48-54%) with a satisfactory delignification degree. Branches lignin was characterized for the first time, evalu...

  13. The effect of amphipilic lignin derivatives addition on enzymatic hydrolysis performance of kraft pulp from sorghum bagasse

    Science.gov (United States)

    Fatriasari, Widya; Nugroho Adi, D. T.; Laksana, R. P. B.; Fajriutami, T.; Raniya, R.; Ghozali, M.; Hermiati, E.

    2018-03-01

    Previously, the chemical characteristics of isolated lignin from Acacia mangium black liquor of kraft pulping was characterized. This lignin was blended with natural rubber latex (NR-L) as adhesive in laminated wood. In addition, lignin has potency for biosurfactant materials by modification of the hydrophobic into hydrophilic properties. Therefore, this study was intended to develop lignin as material for amphipilic lignin derivatives (A-LD) biosurfactant by reacting lignin with epoxilated polyethylene glicol (PEG). A-LD addition in slurries was used to improve the enzymatic hydrolysis (EH) of kraft pulp sweet bagasse sorghum (SSB). The main observation in EH performance was to investigate the effect of lignin isolation method (one and two step) in A-LD and A-LD loading addition on reducing sugar yield (RSY) of SSB kraft pulp. The pulp was hydrolyzed at 50°C and 150 rpm for 72 h with 10 FPU cellulase loading in the shaking incubator. A-LD from one (L1S) and two step (L2S) lignin was added with A-LD loading of 0, 1, 2, 5, and 10% (b/v). The RSY of hydrolyzate has been observed after EH. A-LDs addition in EH of SSB kraft pulp enhanced RSY. L1S worked better in reaction performance with PEDGE compared to L2S and LS. A better performance was showed by PEDGE 500 than that of PEDGE 6000. Generally, the higher A-LDs loading resulted higher RSY. The highest RSY (81.33%) was resulted in addition of 10% A-LD L1S using PEDGE 500. A 5% A-LD loading was more considered to be added in EH because the RSY was comparable with 10% A-LD loading.

  14. Development of a combined piezoresistive pressure and temperature sensor using a chemical protective coating for Kraft pulp digester process monitoring

    International Nuclear Information System (INIS)

    Mohammadi, Abdolreza R; Chiao, Mu; Bennington, Chad P J

    2011-01-01

    We have developed an integrated piezoresistive pressure and temperature sensor for multiphase chemical reactors, primarily Kraft pulp digesters (pH 13.5, temperatures up to 175 °C, reaching a local maximum of 180 °C and pressures up to 2 MPa). The absolute piezoresistive pressure sensor consisted of a large square silicon diaphragm (1000 × 1000 µm 2 ) and high resistance piezoresistors (10 000 Ω). A 4500 Ω buried piezoresistive wire was patterned on the silicon chip to form a piezoresistive temperature sensor which was used for pressure sensor compensation and temperature measurement. A 4 µm thick Parylene HT® coating, a chemically resistant epoxy and a silicone conformal coating were deposited to passivate the pressure sensor against the caustic environment in Kraft digesters. The sensors were characterized up to 2 MPa and 180 °C in an environment chamber. A maximum thermal error of ±0.72% full-scale output (FSO), an average sensitivity of 0.116 mV (V kPa) −1 and a power consumption of 0.3 mW were measured in the pressure sensor. The sensors' resistances were measured before and after test in a Kraft pulping cycle and showed no change in their values. SEM pictures and topographical surfaces were also analyzed before and after pulp liquor exposure and showed no observable changes.

  15. Experimental evaluation of the performances of cellulosic pads made out of Kraft and NSSC corrugated papers as evaporative media

    International Nuclear Information System (INIS)

    Barzegar, Mahsa; Layeghi, Mohammad; Ebrahimi, Ghanbar; Hamzeh, Yahya; Khorasani, Manouchehr

    2012-01-01

    Highlights: ► We experimentally evaluated the performances of cellulosic pads. ► A number of experiments have been done in a wind tunnel. ► The results showed that cooling efficiency improves with decrease of air velocity and flute size. ► Water consumption increases with the increase of air velocity. ► Cooling efficiency of various pads was also compared. - Abstract: The purpose of this study was to evaluate the performances of cellulosic pads made out of Kraft and NSSC corrugated papers in three flute sizes, experimentally. A number of experiments have been done in a wind tunnel in order to evaluate the cooling efficiency and water consumption as a function of air velocity. The tests were carried out at three levels of air velocity (1.8, 2.25, and 2.67 ms −1 ) for three flute sizes of Kraft and NSSC corrugated papers (2.5, 3.5, and 4.5 mm). Analysis of the results indicated that cooling efficiency improves with decrease of air velocity and flute size of corrugated papers; however, water consumption increases with the increase of air velocity. The results were compared with each other and it was shown that the cellulosic pad made out of Kraft paper with 2.5 mm flute size has the highest performance (92%) at 1.8 ms −1 air velocity in comparison with the other cellulosic pads.

  16. Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts

    Science.gov (United States)

    2017-01-01

    Limonite, a low-cost iron ore, was investigated as a potential hydrotreatment catalyst for kraft lignin without the use of an external solvent (batch reactor, initial H2 pressure of 100 bar, 4 h). The best results were obtained at 450 °C resulting in 34 wt % of liquefied kraft lignin (lignin oil) on lignin intake. The composition of the lignin oil was determined in detail (elemental composition, GC-MS, GC×GC-FID, and GPC). The total GC-detectable monomeric species amounts up to 31 wt % on lignin intake, indicating that 92 wt % of the products in the lignin oil are volatile and thus of low molecular weight. The lignin oil was rich in low-molecular-weight alkylphenolics (17 wt % on lignin) and aromatics (8 wt % on lignin). Performance of the limonite catalyst was compared to other Fe-based catalysts (goethite and iron disulfide) and limonite was shown to give the highest yields of alkylphenolics and aromatics. The limonite catalyst before and after reaction was characterized using XRD, TEM, and nitrogen physisorption to determine changes in structure during reaction. Catalyst recycling tests were performed and show that the catalyst is active after reuse, despite the fact that the morphology changed and that the surface area of the catalyst particles was decreased. Our results clearly reveal that cheap limonite catalysts have the potential to be used for the depolymerization/hydrodeoxygenation of kraft lignin for the production of valuable biobased phenolics and aromatics. PMID:28413733

  17. Carbon Nanostructure of Kraft Lignin Thermally Treated at 500 to 1000 °C.

    Science.gov (United States)

    Zhang, Xuefeng; Yan, Qiangu; Leng, Weiqi; Li, Jinghao; Zhang, Jilei; Cai, Zhiyong; Hassan, El Barbary

    2017-08-21

    Kraft lignin (KL) was thermally treated at 500 to 1000 °C in an inert atmosphere. Carbon nanostructure parameters of thermally treated KL in terms of amorphous carbon fraction, aromaticity, and carbon nanocrystallites lateral size ( L a ), thickness ( L c ), and interlayer space ( d 002 ) were analyzed quantitatively using X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy. Experimental results indicated that increasing temperature reduced amorphous carbon but increased aromaticity in thermally treated KL materials. The L c value of thermally treated KL materials averaged 0.85 nm and did not change with temperature. The d 002 value decreased from 3.56 Å at 500 °C to 3.49 Å at 1000 °C. The L a value increased from 0.7 to 1.4 nm as temperature increased from 500 to 1000 °C. A nanostructure model was proposed to describe thermally treated KL under 1000 °C. The thermal stability of heat treated KL increased with temperature rising from 500 to 800 °C.

  18. Structural, morphological, and thermal characterization of kraft lignin and its charcoals obtained at different heating rates

    Science.gov (United States)

    Rodrigues Brazil, Tayra; Nunes Costa, Rogeria; Massi, Marcos; Cerqueira Rezende, Mirabel

    2018-04-01

    Biomass is a renewable resource that is becoming more import due to environmental concerns and possible oil crisis. Thus, optimizing its use is a current challenge for many researchers. Lignin, which is a macromolecule with complex chemical structure, valuable physicochemical properties, and varied chemical composition, is available in large quantities in pulp and paper companies. The objective of this work is the physicochemical characterization of two Kraft lignin samples with different purities, and the study of its thermal conversion into charcoal. The lignin characterization was based on chemical, TGA, DSC, FT-IR, particle sizes, and FEG-SEM analyses. These analyses show that the lignins are mainly composed of guaiacyl and syringyl units, with residues of 30–36 wt.%, in inert atmosphere, depending on the lignin purity. From these results, the more purified lignin with higher carbon yield (%C) was selected for charcoal production. The heat treatment (HT) for carbonization of lignin, at different times (90, 180, and 420 min), resulted in different %C (41–44 wt.%). Longer HT resulted in higher %C and in charcoals with smaller pore sizes. Nanopores (∼50 nm) are observed for the charcoal obtained with the longest HT.

  19. Acid-catalysed xylose dehydration into furfural in the presence of kraft lignin.

    Science.gov (United States)

    Lamminpää, Kaisa; Ahola, Juha; Tanskanen, Juha

    2015-02-01

    In this study, the effects of kraft lignin (Indulin AT) on acid-catalysed xylose dehydration into furfural were studied in formic and sulphuric acids. The study was done using D-optimal design. Three variables in both acids were included in the design: time (20-80 min), temperature (160-180°C) and initial lignin concentration (0-20 g/l). The dependent variables were xylose conversion, furfural yield, furfural selectivity and pH change. The results showed that the xylose conversion and furfural yield decreased in sulphuric acid, while in formic acid the changes were minor. Additionally, it was showed that lignin has an acid-neutralising capacity, and the added lignin increased the pH of reactant solutions in both acids. The pH rise was considerably lower in formic acid than in sulphuric acid. However, the higher pH did not explain all the changes in conversion and yield, and thus lignin evidently inhibits the formation of furfural. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. A practical approach towards energy conversion through bio-refining of mixed kraft pulps

    Energy Technology Data Exchange (ETDEWEB)

    Dharm, D.; Upadhyaya, J.S.; Tyagi, C.H.; Ahamad, S. (Dept. of Paper Technology, Indian Inst. of Technology Roorkee, Saharanpur (India))

    2007-07-01

    The pulp and paper industry is an energy intensive process industry where energy contributes about 16-20% of the manufacturing cost. Due to shortage in energy availability and increase in energy cost, energy conservation has become a necessity in the paper industry. A laboratory study on bleached and unbleached kraft pulps having 15% bamboo, eucalyptus 15%, poplar waste 20% and veneer waste 50% was conducted using two distinct commercial enzymes i.e. cellulases and xylanase and its effect on slowness, drainage time, beating time, mechanical strength properties and power consumption were studied. Enzymatic pretreatment of chemical pulp in laboratory improves degSR by 5 and 4 points in case of bleached and unbleached pulps respectively at the same beating time. Breaking length improves up to 4.0% at the constant beating level. The application of cellulase during refining saves energy 18.5% at constant refining level i.e. 28 degSR. The enzymatic treatment shows a power saving per 100 metric tone of paper by 1390 kWh which costs power saving in euro 160.70/ 100 metric tone of paper. In this way, net cost saving by deducting the cost of enzyme per 100 metric tone of paper is euro 157.90. (orig.)

  1. Effects of the bleaching sequence on the optical brighteners action in eucalyptus kraft pulp

    Directory of Open Access Journals (Sweden)

    Mauro Manfredi

    2014-06-01

    Full Text Available During the bleaching process the pulp is treated with chemical reagents that can be retained in the pulp and interfere in the action of the optical brighteners. Different bleaching sequences can produce pulps at the same brightness but with different potential to whiteness increase when treated with optical brighteners. The objective of this study was to evaluate the influence of the bleaching sequence on the efficiency of disulphonated and tetrasulphonated optical brighteners. Eucalyptus kraft pulp was bleached using four different bleaching sequences. For each pulp three brightness targets were aimeds. For each bleaching sequence mathematical model was generated for predicting the final pulp whiteness according to the initial brightness and the optical brightener charge applied. The presence of organochlorine residues in the pulp reduced the effectiveness of the optical brighteners. Therefore, bleaching sequences that use low chlorine dioxide charge favors for greater gains in whiteness with the application of optical brighteners. The replacement of the final chlorine dioxide bleaching stage with a hydrogen peroxide one in the sequence increased the efficiency of the optical brightening agents.

  2. High-value utilization of eucalyptus kraft lignin: Preparation and characterization as efficient dye dispersant.

    Science.gov (United States)

    Zhang, Hui; Yu, Boming; Zhou, Wanpeng; Liu, Xinxin; Chen, Fangeng

    2018-04-01

    The dark color of industrial lignin is the main obstacle for their high value-added use in areas such as dyestuff dispersants. A kind of light-colored lignosulfonate with favorable dispersibility and remarkable stain resistance is prepared using fractionated eucalyptus kraft lignin. The fractionated lignins named as D (insoluble part) and X (soluble part) and sulfonated lignin fractions named as SD and SX are characterized by FTIR spectroscopy, 1 H NMR spectroscopy, GPC and brightness test. The results reveal that fraction X presents a lower molecular weight but a higher hydroxyl content than that of fraction D, which lead to the differences on the SO 3 H content, dispersibility and color performance of SD and SX. The sulfonated fractions perform a similar molecular weight to that of unsulfonated lignins and show light color due to the phenolic hydroxyl blocking of 1,4-BS (1,4-butane sultone) and the postprocessing of sodium borohydride. The SX that performs the best of all exhibits obvious decrease on phenolic hydroxyl groups and increase on brightness value which is improved by 85.8% compared with control sample. The SX reaches the highest level (grade 5) in the dispersibility test and presents remarkable stain resistance on different textiles, especially on the dacron and cotton. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Electrostatic precipitator performance and trace element emissions from two Kraft recovery boilers.

    Science.gov (United States)

    Lind, Terttaliisa; Hokkinen, Jouni; Jokiniemi, Jorma K; Hillamo, Risto; Makkonen, Ulla; Raukola, Antti; Rintanen, Jaakko; Saviharju, Kari

    2006-01-15

    Fine particle emissions from combustion sources have gained attention recently due to their adverse effects on human health. The emission depends on the combustion process, fuel, and particulate removal technology. Particle concentrations at Kraft recovery boiler exits are very high, and the boilers are typically equipped with electrostatic precipitators (ESP). However, little data are available on the ESP performance in recovery boilers. Particle concentrations and size distributions were determined at two modern, operating recovery boilers. In addition, we determined the fractional collection efficiency of the ESPs by simultaneous measurements at the ESP inlet and outlet and the particulate emissions of trace metals. The particle mass concentration atthe ESP inlet was 11-24 g/Nm3 at the two boilers. Particle emissions were 30-40 mg/ Nm3 at boiler A and 12-15 mg/Nm3 at boiler B. The particle size distributions had a major particle mode at around 1 microm. These fume particles contained most of the particle mass. The main components in the particles were sodium and sulfate with minor amounts of chloride, potassium, and presumably some carbonate. The ESP collection efficiency was 99.6-99.8% at boiler A and 99.9% at boiler B. The particle penetration through the ESP was below 0.6% in the entire fume particle size range of 0.3-3 microm. Trace element emissions from both boilers were well below the limit values set by EU directive for waste incineration.

  4. Catalytic Fast Pyrolysis of Kraft Lignin over Hierarchical HZSM-5 and Hβ Zeolites

    Directory of Open Access Journals (Sweden)

    Yadong Bi

    2018-02-01

    Full Text Available The hierarchical HZSM-5 and Hβ zeolites were prepared by alkaline post-treatment methods adopting Na2CO3, TMAOH/NaOH mixture, and NaOH as desilication sources, respectively. More mesopores are produced over two kinds of zeolites, while the micropores portion is well preserved. The mesopores formed in hierarchical Hβ zeolites were directly related to the basicity of the alkaline solution, indicating that Hβ zeolite is more sensitive to the alkaline post-treatment. The hierarchical HZSM-5 and Hβ zeolites are more active than the parent one for catalytic fast pyrolysis (CFP of Kraft lignin. Hierarchical zeolites retained the function of acid catalysis, while additionally creating larger mesopores to ensure the entry of bulkier reactant molecules. The increase of the condensable volatiles yield can be attributed to the improvement of the mass transfer performance, which correlates well with the change of mesoporous surface area. In particular, the condensable volatiles yield for the optimized hierarchical Hβ reached approximately two times that of the parent Hβ zeolites. In contrast to the parent HZSM-5, the optimized hierarchical HZSM-5 zeolite significantly reduced the selectivity of oxygenates from 27.2% to 3.3%.

  5. Bio-oil production of softwood and hardwood forest industry residues through fast and intermediate pyrolysis and its chromatographic characterization.

    Science.gov (United States)

    Torri, Isadora Dalla Vecchia; Paasikallio, Ville; Faccini, Candice Schmitt; Huff, Rafael; Caramão, Elina Bastos; Sacon, Vera; Oasmaa, Anja; Zini, Claudia Alcaraz

    2016-01-01

    Bio-oils were produced through intermediate (IP) and fast pyrolysis (FP), using Eucalyptus sp. (hardwood) and Picea abies (softwood), wood wastes produced in large scale in Pulp and Paper industries. Characterization of these bio-oils was made using GC/qMS and GC×GC/TOFMS. The use of GC×GC provided a broader characterization of bio-oils and it allowed tracing potential markers of hardwood bio-oil, such as dimethoxy-phenols, which might co-elute in 1D-GC. Catalytic FP increased the percentage of aromatic hydrocarbons in P. abies bio-oil, indicating its potential for fuel production. However, the presence of polyaromatic hydrocarbons (PAH) draws attention to the need of a proper management of pyrolysis process in order to avoid the production of toxic compounds and also to the importance of GC×GC/TOFMS use to avoid co-elutions and consequent inaccuracies related to identification and quantification associated with GC/qMS. Ketones and phenols were the major bio-oil compounds and they might be applied to polymer production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Brown rot fungal early stage decay mechanism as a biological pretreatment for softwood biomass in biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Michael J.; Leak, David J.; Spanu, Pietro D.; Murphy, Richard J. [Division of Biology, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ (United Kingdom); Porter Alliance, Imperial College London, London SW7 2AZ (United Kingdom)

    2010-08-15

    A current barrier to the large-scale production of lignocellulosic biofuels is the cost associated with the energy and chemical inputs required for feedstock pretreatment and hydrolysis. The use of controlled partial biological degradation to replace elements of the current pretreatment technologies would offer tangible energy and cost benefits to the whole biofuel process. It has been known for some time from studies of wood decay that, in the early stages of growth in wood, brown rot fungi utilise a mechanism that causes rapid and extensive depolymerisation of the carbohydrate polymers of the wood cell wall. The brown rot hyphae act as delivery vectors to the plant cell wall for what is thought to be a combination of a localised acid pretreatment and a hydroxyl radical based depolymerisation of the cell wall carbohydrate polymers. It is this quality that we have exploited in the present work to enhance the saccharification potential of softwood forest residues for biofuel production. Here we show that after restricted exposure of pine sapwood to brown rot fungi, glucose yields following enzymatic saccharification are significantly increased. Our results demonstrate the potential of using brown rot fungi as a biological pretreatment for biofuel production. (author)

  7. Effect of biodegradation on thermogravimetric and chemical characteristics of hardwood and softwood by brown-rot fungus.

    Science.gov (United States)

    Gao, Zhenzhong; Fan, Qi; He, Zesen; Wang, Zhinan; Wang, Xiaobo; Sun, Jin

    2016-07-01

    The thermogravimetric and chemical characterization of hardwood Eucalyptus urophylla (Ep) and softwood Pinus massoniana (Mp) pretreated by brown-rot fungus Gloeophyllum trabeum were investigated. The results indicated that the brown-rot fungus pretreatment can optimize the thermal decomposition and decrease the initiation temperatures (8-11°C lower) of both the Ep and Mp pyrolysis. The mean activation energy values of the bio-treated samples were 29.7kJ/mol (for Ep) and 42.3kJ/mol (for Mp) lower than that of the un-treated samples at the conversion rate from 0.1 to 0.7 based on Flynn-Wall-Ozawa (FWO) method. After the bio-pretreatment, the required temperatures were lower (4-7°C) for the pyrolysis rates of hemicellulose and cellulose in Mp reaching maximum and termination. However, the situation was just the opposite for Ep. The variations in chemical properties of hydrogen bonding, as well as the relative changes in lignin/carbohydrate composition of both wood species were also examined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Preparation and Characterization of K2CO3-Activated Kraft Lignin Carbon

    Directory of Open Access Journals (Sweden)

    Xian-fa Li

    2016-01-01

    Full Text Available A series of activated carbons (ACs were prepared by K2CO3 activation from kraft lignin (KL that was recovered from papermaking black liquor. The effects of process parameters such as the activation temperature (AT, activated period, K2CO3 to KL mass ratio, and N2 flow rate on the characteristics of the final product were determined. The ACs were characterized using nitrogen adsorption, morphology, and fractal dimension analyses. The results showed that the AT was the main factor influencing the yield, surface area, and pore structure. The yield of ACs obviously decreased from 50.6% to 20.5% with increasing AT from 600 °C to 1000 °C, and decreased with increasing K2CO3/KL mass ratio. Activation time and N2 flow rate had slight effect on the yield of ACs. The surface area and total pore volume increased as the AT rose to 900 °C and then decreased with further increases in temperature. The maximum surface area and total pore volume were 1816.3 m2/g and 1.26 cm3/g, respectively, at a K2CO3 to KL mass ratio of 3:1, AT of 900 °C, activation time of 2 h, and N2 flow rate of 70 cm3/min. The pore structure of the ACs could be tailored by controlling the AT. As the AT was increased from 700 to 1000 °C, the mesoporosity increased from 11.6% to 95.9%. SEM images indicated that the morphology of ACs was modified by the AT. The K2CO3 was partially recycled.

  9. Correlation of Process Data and Electrochemical Noise to Assess Kraft Digester Corrosion: Kamloops Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, SJ

    2002-05-09

    Electrochemical noise (ECN) probes were deployed in a carbon steel continuous kraft digester at five locations roughly equi-spaced from top to bottom of the vessel. Current and potential noise, the temperature at each probe location, and the value of about 60 process parameters (flow rates, liquor chemistry, etc.) were monitored continuously for a period of one year. Historical vessel inspection data, including inspections accomplished immediately prior to and immediately following probe deployment, and post-test evaluation of the probe components were used to assess/compare corrosion indications from the probes with physical changes in wall thickness and corrosion patterns on the digester shell. The results indicate that furnish composition is a significant variable influencing digester corrosion, with increasing amounts of Douglas fir in the nominal furnish correlating directly with increased corrosion activity on the ECN probes. All five probes detected changes in furnish composition approximately simultaneously, indicating rapid chemical communication through the liquor, but the effect was strongest and persisted longest relatively high in the digester. The ECN probes also indicate significant corrosion activity occurred at each probe position during shutdown/restart transients. Little or no correlation between ECN probe corrosion activity and other operational variables was observed. Post-test evaluation of the probes confirmed general corrosion of a magnitude that closely agreed with corrosion current sums calculated for each probe over the exposure period and with historical average corrosion rates for the respective locations. Further, no pitting was observed on any of the electrodes, which is consistent with the ECN data, relevant polarization curves developed for steel in liquor removed from the digester, and the post-test inspection of the digester.

  10. Irrigation model of bleached Kraft mill wastewater through volcanic soil as a pollutants attenuation process.

    Science.gov (United States)

    Navia, R; Inostroza, X; Diez, M C; Lorber, K E

    2006-05-01

    An irrigation process through volcanic soil columns was evaluated for bleached Kraft mill effluent pollutants retention. The system was designed to remove color and phenolic compounds and a simple kinetic model for determining the global mass transfer coefficient and the adsorption rate constant was used. The results clearly indicate that the global mass transfer coefficient values (K(c)a) and the adsorption rate constants are higher for the irrigation processes onto acidified soil. This means that the pretreatment of washing the volcanic soil with an acid solution has a positive effect on the adsorption rate for both pollutant groups. The enhanced adsorption capacity is partially explained by the activation of the metal oxides present in the soil matrix during the acid washing process. Increasing the flow rate from 1.5 to 2.5 ml/min yielded higher (K(c)a) values and adsorption rate constants for both pollutant groups. For instance, regarding color adsorption onto acidified soil, there is an increment of 43% in the (K(c)a) value for the experiment with a flow rate of 2.5 ml/min. Increasing the porosity of the column from 0.55 to 0.59, yielded a decrease in the (K(c)a) values for color and phenolic compounds adsorption processes. Onto natural soil for example, these decreases reached 21% and 24%, respectively. Therefore, the (K(c)a) value is dependent on both the liquid-phase velocity (external resistance) and the soil fraction in the column (internal resistance); making forced convection and diffusion to be the main transport mechanisms involved in the adsorption process. Analyzing the adsorption rate constants (K(c)a)/m, phenolic compounds and color adsorption rates onto acidified soil of 2.25 x 10(-6) and 2.62 x 10(-6) l/mg min were achieved for experiment 1. These adsorption rates are comparable with other adsorption systems and adsorbent materials.

  11. Fibre Morphological Characteristics of Kraft Pulps of Acacia melanoxylon Estimated by NIR-PLS-R Models

    Directory of Open Access Journals (Sweden)

    Helena Pereira

    2015-12-01

    Full Text Available In this paper, the morphological properties of fiber length (weighted in length and of fiber width of unbleached Kraft pulp of Acacia melanoxylon were determined using TECHPAP Morfi® equipment (Techpap SAS, Grenoble, France, and were used in the calibration development of Near Infrared (NIR partial least squares regression (PLS-R models based on the spectral data obtained for the wood. It is the first time that fiber length and width of pulp were predicted with NIR spectral data of the initial woodmeal, with high accuracy and precision, and with ratios of performance to deviation (RPD fulfilling the requirements for screening in breeding programs. The selected models for fiber length and fiber width used the second derivative and first derivative + multiplicative scatter correction (2ndDer and 1stDer + MSC pre-processed spectra, respectively, in the wavenumber ranges from 7506 to 5440 cm−1. The statistical parameters of cross-validation (RMSECV (root mean square error of cross-validation of 0.009 mm and 0.39 μm and validation (RMSEP (root mean square error of prediction of 0.007 mm and 0.36 μm with RPDTS (ratios of performance to deviation of test set values of 3.9 and 3.3, respectively, confirmed that the models are robust and well qualified for prediction. This modeling approach shows a high potential to be used for tree breeding and improvement programs, providing a rapid screening for desired fiber morphological properties of pulp prediction.

  12. Life cycle environmental performance of renewable building materials in the context of residential construction : phase II research report: an extension to the 2005 phase I research report. Module D, Life cycle inventory of softwood lumber manufacturing in the Northeastern and North Central United States.

    Science.gov (United States)

    Richard D. Bergman; Scott A. Bowe

    2009-01-01

    The goal of this study was to gain an understanding of the environmental impact for softwood lumber production through a gate-to-gate life-cycle inventory (LCI) of softwood sawmills in the northeastern and north central United States (NE/NC). Primary mill data were collected per Consortium on Research for Renewable Industrial Material (CORRIM) Research Guidelines (...

  13. Production-ecological analysis of herb layer in the softwood floodplain forests formed after the gabčíkovo waterwork construction and their characteristics

    Directory of Open Access Journals (Sweden)

    Vojtková Jana

    2014-03-01

    Full Text Available This paper is focused on phytocoenological characteristics and production analysis of herbaceous layer biomass of the softwood floodplain forests (Salici-Populetum (R. Tx. 1931 Meijer Drees 1936 association and their phytocoenological characteristics. The sampling site was located in the young stands, which were formed after the Gabčíkovo Waterwork construction in 1992. Redirection of the major ratio of flow into the supply channel has caused essential decrease of water level in the old Danube riverbed. As a result of this, new bare sites have appeared having character of pioneer habitat. In the process of primary succession, new softwood floodplain forests have formed here within a few years. These stands are the subject of the study presented in this paper. We estimated herb layer biomass using indirect sampling modified for non-repeated field measurements (Kubíček, Brechtl, 1970. Total biomass of herbaceous layer was estimated to be 5577 kg ha−1, the aboveground biomass was 4065 kg ha−1 while the belowground biomass was 1512 kg ha−1. The results were compared with the data of Kubíček et al. (2009 and Kollár et al. (2010. Some attention was also paid to their phytocoenologic characteristics. Considering this, it seems that they represent full-value softwood floodplain forest of the Salici-Populetum association despite a bit higher occurrence of some synanthropic species. Such statement is supported by comparison with the data of Jurko (1958 and Šomšák (2003.

  14. Cytotoxic and genotoxic responses of human lung cells to combustion smoke particles of Miscanthus straw, softwood and beech wood chips

    Science.gov (United States)

    Arif, Ali Talib; Maschowski, Christoph; Garra, Patxi; Garcia-Käufer, Manuel; Petithory, Tatiana; Trouvé, Gwenaëlle; Dieterlen, Alain; Mersch-Sundermann, Volker; Khanaqa, Polla; Nazarenko, Irina; Gminski, Richard; Gieré, Reto

    2017-08-01

    Inhalation of particulate matter (PM) from residential biomass combustion is epidemiologically associated with cardiovascular and pulmonary diseases. This study investigates PM0.4-1 emissions from combustion of commercial Miscanthus straw (MS), softwood chips (SWC) and beech wood chips (BWC) in a domestic-scale boiler (40 kW). The PM0.4-1 emitted during combustion of the MS, SWC and BWC were characterized by ICP-MS/OES, XRD, SEM, TEM, and DLS. Cytotoxicity and genotoxicity in human alveolar epithelial A549 and human bronchial epithelial BEAS-2B cells were assessed by the WST-1 assay and the DNA-Alkaline Unwinding Assay (DAUA). PM0.4-1 uptake/translocation in cells was investigated with a new method developed using a confocal reflection microscope. SWC and BWC had a inherently higher residual water content than MS. The PM0.4-1 emitted during combustion of SWC and BWC exhibited higher levels of Polycyclic Aromatic Hydrocarbons (PAHs), a greater variety of mineral species and a higher heavy metal content than PM0.4-1 from MS combustion. Exposure to PM0.4-1 from combustion of SWC and BWC induced cytotoxic and genotoxic effects in human alveolar and bronchial cells, whereby the strongest effect was observed for BWC and was comparable to that caused by diesel PM (SRM 2 975), In contrast, PM0.4-1 from MS combustion did not induce cellular responses in the studied lung cells. A high PAH content in PM emissions seems to be a reliable chemical marker of both combustion efficiency and particle toxicity. Residual biomass water content strongly affects particulate emissions and their toxic potential. Therefore, to minimize the harmful effects of fine PM on health, improvement of combustion efficiency (aiming to reduce the presence of incomplete combustion products bound to PM) and application of fly ash capture technology, as well as use of novel biomass fuels like Miscanthus straw is recommended.

  15. Atmospheric emission of nitrogen oxide from kraft recovery boilers in Sweden

    International Nuclear Information System (INIS)

    Kjoerk, Anders; Herstad Swaerd, Solvie

    2000-05-01

    Recovery boiler NO x emissions are low compared with those from power boilers. However tighter environmental requirements to decrease the acidic emissions implies that all sources have to be addressed. There are an ongoing evaluation and development of NO x control technologies in the pulp industry. Basically air staging, selective catalytic reduction, SCR, and selective noncatalytic reduction, SNCR, have been discussed. Other NO x control options may be available as a result of ongoing research and development. As a background in the work to reduce the acid rain it has been considered necessary to have a good picture of the NO x emission from recovery boilers, and the Thermal Engineering Research Institute in Sweden have therefore sponsored this study. The intention is to give a good general view and try to explain the reasons for the large differences between boilers. Data from the 30 kraft recovery boilers which were in operation in Sweden during 1999 have been collected. Both NO x levels and specific conditions which could have an influence on the level have been included. The evaluation show a clear correlation between the nitrogen content in the liquor and the NO x level. It seams also that a long retention time in the furnace give an opportunity to reduce the amount of nitrogen oxide. For most boilers in Sweden the NO x levels are reported in mg/MJ and comparison could be done between different types of boilers. However for recovery boilers there could be a large uncertainty in the calculation which gives the amount (mg) of NO x , the definition of the heat input to be used (MJ) is either not clear. As a base for the study the measured concentration in ppm is used instead. The reported values are in the range of 30 - 100 ppm, however the majority of the boilers operate in a more narrow range 60-80 ppm. Air staging and other combustion methods could not reasonably reduce the NO x emission with more than 20% in the next decade. If the goal is higher other

  16. Influência dos atributos do solo sobre a qualidade da madeira de Pinus taeda para produção de celulose Kraft Influence of soil attributes on quality of Pinus taeda wood for cellulose Kraft production

    Directory of Open Access Journals (Sweden)

    Patrícia Aparecida Rigatto

    2004-04-01

    Full Text Available Neste trabalho foram analisados os efeitos dos atributos do solo sobre a qualidade da madeira de Pinus taeda para produção de celulose Kraft, em áreas da Klabin, em Telêmaco Borba-PR. Foram estudados oito sítios com árvores de 12 anos de idade, selecionados pelo tipo de solo, textura e vegetação primária. Para caracterização dos sítios foram realizadas coletas de amostras em três horizontes, tendo sido coletadas amostras indeformadas e compostas, analisando-se as seguintes variáveis no solo: densidade global, porosidade total, macroporosidade, disponibilidade de água, fertilidade e granulometria. Selecionaram-se cinco árvores médias por sítio, nas quais foram medidos as alturas total e comercial e o DAP e retirados discos, sendo este material ensaiado quanto a densidade básica, composição química, características morfológicas dos traqueídeos e produção de celulose Kraft. Com relação às propriedades da madeira, os atributos físicos do solo demonstraram ter maior influência. De modo geral, as madeiras provenientes de sítios com texturas mais argilosas apresentaram menores valores de densidade básica; maiores teores de extrativos e lignina; menores teores de holocelulose e celulose; traqueídeos mais curtos, mais largos, com paredes mais finas e com diâmetros do lúmen maiores; e menor rendimento em celulose. A partir destes resultados, concluiu-se ser possível a previsão de propriedades da polpa através da análise das características da madeira associada às condições edáficas reinantes.To meet the increasing demand for forest products, much of the future timber supply will come from trees grown in managed plantations. This work was carried out to analyze the effects of soil attributes on Pinus taeda wood quality to produce Kraft cellulose at Klabin Parana Cellulose Co., in Telêmaco Borba, PR, Brazil. The study focused on the influence of soil attributes on the anatomical, physical and chemical wood

  17. Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill Características químicas e polpação Kraft de madeira de tração de Eucalyptus globulus labill

    Directory of Open Access Journals (Sweden)

    María Graciela Aguayo

    2012-12-01

    Full Text Available Tension (TW and opposite wood (OW of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively. The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EOD1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.Madeira de tração e oposta de árvores de Eucalyptus globulus foram analisadas quanto a suas características químicas e produção de polpa Kraft. A caracterização química da madeira de tração (TW de Eucalyptus globulus Labill. mostrou um conteúdo similar de celulose, alto conteúdo de xilanas e baixo conteúdo de lignina quando comparada com a madeira oposta (OW de uma mesma árvore. O conteúdo de lignina foi 16% menor e contém 32% mais unidades siringila em TW que em OW. O aumento das unidades siringila favoreceu a formação de ligações

  18. Mineral phases of green liquor dregs, slaker grits, lime mud and wood ash of a Kraft pulp and paper mill

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Fernanda Machado [Laboratorio de Quimica Mineral Aplicada, Departamento de Quimica-UFPR, Universidade Federal do Parana (UFPR), CP 19081, CEP 81531990, Curitiba-PR (Brazil); Munhoz Martins, Joaniel [Laboratorio de Analise de Minerais e Rochas (LAMIR-UFPR) (Brazil); Ferracin, Luiz Carlos [Laboratorio Quimico da Votorantin Cimentos (Brazil); Cunha, Carlos Jorge da [Laboratorio de Quimica Mineral Aplicada, Departamento de Quimica-UFPR, Universidade Federal do Parana (UFPR), CP 19081, CEP 81531990, Curitiba-PR (Brazil)]. E-mail: cjdcunha@quimica.ufpr.br

    2007-08-17

    Four residues generated in a Kraft, pulp and paper plant, were characterized by X-ray fluorescence spectroscopy (XFA), powder X-ray diffraction (XRD), thermogravimmetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). A quantitative phase composition model, that accounts for the observed data and for the physico-chemical conditions of formation, was postulated for each material. Emphasis was given on the identification of the mineral components of each material. The green liquor dregs and the lime mud contain Calcite and Gipsite. The slaker grits contains Calcite, Portlandite, Pirssonite, Larnite and Brucite. The Calcite phase, present in the dregs and in the lime mud, has small amounts of magnesium replacing calcium. The wood ash contains Quartz as the major crystalline mineral phase.

  19. Mineral phases of green liquor dregs, slaker grits, lime mud and wood ash of a Kraft pulp and paper mill

    International Nuclear Information System (INIS)

    Martins, Fernanda Machado; Munhoz Martins, Joaniel; Ferracin, Luiz Carlos; Cunha, Carlos Jorge da

    2007-01-01

    Four residues generated in a Kraft, pulp and paper plant, were characterized by X-ray fluorescence spectroscopy (XFA), powder X-ray diffraction (XRD), thermogravimmetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). A quantitative phase composition model, that accounts for the observed data and for the physico-chemical conditions of formation, was postulated for each material. Emphasis was given on the identification of the mineral components of each material. The green liquor dregs and the lime mud contain Calcite and Gipsite. The slaker grits contains Calcite, Portlandite, Pirssonite, Larnite and Brucite. The Calcite phase, present in the dregs and in the lime mud, has small amounts of magnesium replacing calcium. The wood ash contains Quartz as the major crystalline mineral phase

  20. Effect of raw wood supply system on the wood paying capability of a kraft pulp mill using Scots pine

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, O. (Helsinki Univ. of Technology, Espoo (Finland), Dept. of Forest Products Technology), Email: olli.dahl@tkk.fi; Jylhae, P. (Finnish Forest Research Inst., Kannus (Finland)), Email: paula.jylha@metla.fi; Laitila, J. (Finnish Forest Research Inst., Joensuu (Finland)), Email: juha.laitila@metla.fi; Kaerhae, K. (Metsaeteho Oy, Helsinki (Finland)), Email: kalle.karha@metsateho.fi

    2009-07-01

    Integration of energy wood procurement into that of pulpwood is seen as a means for reducing the high procurement costs of small-diameter wood harvested from first thinnings. In the deepest mode of integration, pulp and energy fractions are separated from each other in the debarking drum of the pulp mill. In the present paper, the competitiveness of the conventional supply chain based on cut-to-length harvesting was compared to the supply systems based on the harvesting of loose whole trees and whole-tree bundling, in the cases of three Scots pine-dominated first-thinning stands using wood paying capability (WPC) of a kraft pulp mill as a decisive criterion. Furthermore, the competitiveness of first thinnings as raw material sources for a pulp mill was evaluated by using intermediate thinnings as s reference. (orig.)

  1. Process integration and waste heat recovery in Lithuanian and Danish industry. Case study: Chocolate factory `Kraft Jacobs Suchard`

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    Kraft Jacbobs is a manufacturer of chocolate. The company is planning investments in order to improve the quality and to increase the production. In this connection they are interested energy savings, in reduction of the sewerage, and in the possibilities of water treatment. The investigation has focused on improvement of the utility system and has therefore not been a real process integration study. The existing needs for cooling and heating in the process have been used in the optimisation. The report indicates that it is possible to save up to 50% of the cold water consumption mainly by building a closed water cooling system and by simple renovation. As much as 40% reduction on the heating cost for processes may be possible by changing parameters, insulation, renovation, and automation. The total annual saving will be about 900,000 Litas if all proposals are implemented. (au)

  2. A Cost-Benefit Assessment of Gasification-Based Biorefining in the Kraft Pulp and Paper Industry

    Energy Technology Data Exchange (ETDEWEB)

    Eric D. Larson; Stefano Consonni; Ryan E. Katofsky; Kristiina Iisa; W. James Frederick

    2007-03-31

    Production of liquid fuels and chemicals via gasification of kraft black liquor and woody residues (''biorefining'') has the potential to provide significant economic returns for kraft pulp and paper mills replacing Tomlinson boilers beginning in the 2010-2015 timeframe. Commercialization of gasification technologies is anticipated in this period, and synthesis gas from gasifiers can be converted into liquid fuels using catalytic synthesis technologies that are in most cases already commercially established today in the ''gas-to-liquids'' industry. These conclusions are supported by detailed analysis carried out in a two-year project co-funded by the American Forest and Paper Association and the Biomass Program of the U.S. Department of Energy. This work assessed the energy, environment, and economic costs and benefits of biorefineries at kraft pulp and paper mills in the United States. Seven detailed biorefinery process designs were developed for a reference freesheet pulp/paper mill in the Southeastern U.S., together with the associated mass/energy balances, air emissions estimates, and capital investment requirements. Commercial (''Nth'') plant levels of technology performance and cost were assumed. The biorefineries provide chemical recovery services and co-produce process steam for the mill, some electricity, and one of three liquid fuels: a Fischer-Tropsch synthetic crude oil (which would be refined to vehicle fuels at existing petroleum refineries), dimethyl ether (a diesel engine fuel or LPG substitute), or an ethanol-rich mixed-alcohol product. Compared to installing a new Tomlinson power/recovery system, a biorefinery would require larger capital investment. However, because the biorefinery would have higher energy efficiencies, lower air emissions, and a more diverse product slate (including transportation fuel), the internal rates of return (IRR) on the incremental capital investments would be

  3. Swelling and hydrolysis kinetics of Kraft pulp fibers in aqueous 1-butyl-3-methylimidazolium hydrogen sulfate solutions.

    Science.gov (United States)

    Mao, Jia; Abushammala, Hatem; Pereira, Laura Barcellos; Laborie, Marie-Pierre

    2016-11-20

    1Butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) is efficient at extracting cellulose nanocrystals from pulp fibers. To shed some light on the respective contributions of swelling and hydrolysis of pulp fibers by [Bmim]HSO4, the physical, structural and morphological characteristics of hardwood Kraft pulp fibers were monitored under various conditions of temperature, water content and time. Swelling was largely compounded by hydrolysis at the highest temperatures (120°C) as evidenced by mass loss and reduced degree of polymerization (DPn) at this temperature. At 120°C only, water content appeared to play a significant role on the extent of hydrolysis. At this temperature, a heterogeneous kinetic model involving weak links and amorphous regions best described the experimental data. Hydrolysis rates were maximum at 25% water content in the aqueous ionic liquid. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Polpação soda com aditivos e cinética de deslignificação Kraft

    OpenAIRE

    Almeida, Diego Pierre de

    2014-01-01

    O método de polpação química Kraft é o mais utilizado mundialmente para produção de celulose, por suas características favoráveis como alta qualidade do papel produzido. Porém possui a desvantagem da poluição odorífera e um complexo sistema de recuperação do licor negro gerado. O processo soda pode ser uma alternativa para produção de polpa celulósica sem compostos a base de enxofre e com melhores qualidades se acrescida de aditivos de cozimento. Este trabalho trata de algumas alternativas pa...

  5. The petroleum industry and climate issues; KonKraft rapport 5; Petroleumsnaeringen og klimaspoersmaal

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Broad scientific agreement prevails that human-produced (anthropogenic) greenhouse gas emissions affect the climate. The UN Intergovernmental Panel on Climate Change (IPCC) has established that such emissions must be significantly reduced to avoid serious consequences for the environment and society. Norway's petroleum industry recognises the climate challenge and has long worked to cut its emissions. These efforts avoided 40 million tonnes of carbon emissions in 1994-2007. The figure for 2006 alone was 4.5 million tonnes of carbon dioxide. Carbon capture and storage (CCS) has furthermore been initiated for natural gas production on the Snoehvit field in the Barents Sea, while the Gjoea and Valhall fields in the North Sea are to be powered from shore. These moves represent an annual cut of 1.3 million tonnes in carbon emissions by 2010. Further reduction measures totalling 800 000 tonnes per annum by 2013 have also been identified, and will help confirm Norway's position as the world's cleanest oil and gas producer. Norwegian greenhouse gas emissions, measured in carbon equivalent, totalled 55 million tonnes in 2007. Carbon dioxide accounted for 44.9 million tonnes. The total for the Norwegian continental shelf (NCS) was 13.8 million tonnes, including 13.2 million tonnes of carbon dioxide. KonKraft report 5 includes an account of action taken to reduce emissions from the NCS and measures planned for the future. The most power-intensive processes on an offshore installation are compression related to gas transport, injection of gas and water for pressure support, and pumping of oil and condensate. Power for these processes is largely generated by gas turbines, which provide the bulk of carbon emissions from the NCS. Flaring has accounted for about 10 per cent in recent years, but this share rose in 2007 because of start-up problems with the Snoehvit plant at Melkoeya Maturation of the NCS and the shift from oil to gas production will boost carbon

  6. Electrochemical acidification of Kraft black liquor by electrodialysis with bipolar membrane: Ion exchange membrane fouling identification and mechanisms.

    Science.gov (United States)

    Haddad, Maryam; Mikhaylin, Sergey; Bazinet, Laurent; Savadogo, Oumarou; Paris, Jean

    2017-02-15

    Integrated forest biorefinery offers promising pathways to sustainably diversify the revenue of pulp and paper industry. In this context, lignin can be extracted from a residual stream of Kraft pulping process, called black liquor, and subsequently converted into a wide spectrum of bio-based products. Electrochemical acidification of Kraft black liquor by electrodialysis with bipolar membrane results in lignin extraction and caustic soda production. Even though the implementation of this method requires less chemicals than the chemical acidification process, fouling of the ion exchange membranes and especially bipolar membrane impairs its productivity. Membrane thickness and ash content measurements along with scanning electron microscopy (SEM), elemental analysis (EDX) and X-ray photoelectron spectrometry (XPS) analysis were performed to identify the nature and mechanisms of the membrane fouling. The results revealed that the fouling layer mostly consisted of organic components and particularly lignin. Based on our proposed fouling mechanisms, throughout the electrodialysis process the pH of the black liquor gradually decreased and as a result more proton ions were available to trigger protonation reaction of lignin phenolic groups and decrease the lignin solubility. Due to the abundance of the proton ions on the surface of the cation exchange layers of the bipolar membrane, destabilized lignin macro-molecules started to self-aggregate and formed lignin clusters on its surface. Over the time, these lignin clusters covered the entire surface of the bipolar membrane and the spaces between the membranes and, eventually, attached to the surface of the cation exchange membrane. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Oil and gas activities in northern Norway; KonKraft rapport 6; Olje- og gassvirksomhet i nord

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    KonKraft report 6 deals with oil and gas operations on the Norwegian continental shelf (NCS) from Nordland county and northwards. It aims to contribute to a broad factual base for decision processes related to opening new exploration areas in these waters. The Norwegian petroleum sector employs about 250 000 people directly and indirectly. It accounts for a third of government revenues, and 90 per cent of its profits accrue to the state. NOK 119 billion of the central government budget in 2009 comes directly from oil and gas revenues. These funds finance roads, nursery schools, hospitals and the Norwegian welfare state. In addition, they safeguard future pensions. This industry is at a crossroads today. Oil production has dropped by 30 per cent since 2000. Recent forecasts from the Norwegian Petroleum Directorate show that it may be reduced by 50 per cent from its peak by 2013. Overall oil and gas output is expected to begin falling from the middle of the next decade. To slow this decline in output and revenues, the oil companies need access to new and attractive exploration acreage. Half the production expected by the government in 2030 relates to resources which have yet to be proven. Opening further areas of the NCS to petroleum activities would contribute to maintaining substantial investment and revenues for the community, and to continuing the development of industry in the northernmost parts of the country. The report reviews unopened areas along the Norwegian coast from the Helgeland region and north-eastwards to the Russian border. Nordland VI and VII plus Troms II are regarded by the petroleum industry as the most promising regions for big discoveries which could slow the production decline. The KonKraft 2 report concerning production development on the NCS estimates remaining resources in these three areas at 3.4 billion barrels of oil equivalent (boe). (Author)

  8. QUALIDADE DA CELULOSE KRAFT-ANTRAQUINONA DE Eucalyptus dunnii PLANTADO EM CINCO ESPAÇAMENTOS EM RELAÇÃO AO Eucalyptus grandis E Eucalyptus saligna

    OpenAIRE

    Maria Cladis Mezzomo da Silva; Edvins Ratnieks; Teotônio Francisco de Assis; Celso Edmundo B. Foelkel; Jorge Vieira Gonzaga; Giovanni Willer Ferreira

    1997-01-01

    Este trabalho analisou o efeito de cinco espaçamentos de Eucalyptus dunnii (3 m x 1 m; 3 m x 1,5 m; 3 m x 2 m; 3 m x 3 m; 3 m x 4 m), para produção de celulose kraft-antraquinona, comparados com Eucalyptus grandis e Eucalyptus saligna (ambos no espaçamento 3 m x 2 m). Avaliaram-se a densidade básica e composição química da madeira original, analisando-se extrativos em diclorometano, pentosanas, lignina, solubilidade em NaOH8% e cinzas. Os cavacos foram submetidos a cozimento kraft-antraquinon...

  9. Process integration study of a kraft pulp mill converted to an ethanol production plant – part B: Techno-economic analysis

    International Nuclear Information System (INIS)

    Fornell, Rickard; Berntsson, Thore; Åsblad, Anders

    2012-01-01

    In a previous study by the authors, energy efficiency measures in a conceptual kraft pulp mill converted to a lignocellulosic ethanol plant were investigated. The results suggested a number of different process designs which would give a substantial improvement in steam economy in the ethanol plant, compared to the original design. In the present study the different process designs are evaluated from an economic point-of-view, in order to determine if energy efficiency measures and increasing by-product sales decrease the production cost of ethanol from this specific process, or if the increased costs related to the implementation of these measures overshadow the benefits from increased by-product sales. The different energy efficiency measures are compared with less capital demanding alternatives (i.e. including low or no energy efficiency improvements) in order to assess the economic benefits of different strategies when converting a kraft pulp mill to ethanol production. The study indicates the economic importance of considering energy efficiency measures when repurposing a kraft pulp mill to an ethanol plant. It is also shown that, within the context of this study, a larger investment in measures will give better economic results than less capital demanding alternatives (with less improvement in energy efficiency). From an economic and energy efficiency viewpoint many of the suggested process designs will give approximately similar results, therefore the process design should be made based on other criteria (e.g. low complexity, low maintenance). - Highlights: ► Conversion of a kraft pulp mill to ethanol production. ► Heat integration of distillation/evaporation in a lignocellulosic ethanol plant. ► Energy efficiency measures lead to lower ethanol production cost. ► If capital costs and raw material prices are low the production cost could be as low as 365 €/m 3 EtOH.

  10. Process integration study of a kraft pulp mill converted to an ethanol production plant – Part A: Potential for heat integration of thermal separation units

    International Nuclear Information System (INIS)

    Fornell, Rickard; Berntsson, Thore

    2012-01-01

    Energy efficiency is an important parameter for the profitability of biochemical ethanol production from lignocellulosic raw material. The yield of ethanol is generally low due to the limited amount of fermentable compounds in the raw material. Increasing energy efficiency leads to possibilities of exporting more by-products, which in turn might reduce the net production cost of ethanol. Energy efficiency is also an important issue when discussing the repurposing of kraft pulp mills to biorefineries, since the mills in question most likely will be old and inefficient. Investing in energy efficiency measures might therefore have a large effect on the economic performance. This paper discusses energy efficiency issues related to the repurposing of a kraft pulp mill into a lignocellulosic ethanol production plant. The studied process is a typical Scandinavian kraft pulp mill that has been converted to a biorefinery with ethanol as main product. A process integration study, using pinch analysis and process simulations, has been performed in order to assess alternative measures for improving the energy efficiency. The improvements found have also been related to the possibilities for by-product sales from the plant (electricity and/or lignin). In a forthcoming paper, which is the second part of this process integration study, an economic analysis based on the results from this paper will be presented. - Highlights: ► Conversion of a kraft pulp mill to ethanol production. ► Heat integration of distillation/evaporation in a lignocellulosic ethanol plant. ► Advanced pinch curves used to find new integration possibilities. ► 35–40% reduction of steam demand.

  11. The reactivity of phenolic and non-phenolic residual kraft lignin model compounds with Mn(II)-peroxidase from Lentinula edodes.

    Science.gov (United States)

    Crestini, C; D'Annibale, A; Sermanni, G G; Saladino, R

    2000-02-01

    Three phenolic model compounds representing bonding patterns of residual kraft lignin were incubated with manganese peroxidase from Lentinula edodes. Extensive degradation of all the phenolic models, mainly occurring via side-chain benzylic oxidation, was observed. Among the tested model compounds the diphenylmethane alpha-5 phenolic model was found to be the most reactive, yielding several products showing oxidation and fragmentation at the bridging position. The non-phenolic 5-5' biphenyl and 5-5' diphenylmethane models were found unreactive.

  12. Study of lignin biotransformation by Aspergillus fumigatus and white-rot fungi using 14C-labeled and unlabeled kraft lignins

    International Nuclear Information System (INIS)

    Kadam, K.K.; Drew, S.W.

    1986-01-01

    The biodegradation of lignin by fungi was studied in shake flasks using 14 C-labeled kraft lignin and in a deep-tank fermentor using unlabeled kraft lignin. Among the fungi screened, A. fumigatus - isolated in our laboratories - was most potent in lignin biotransformation. Dialysis-type fermentation, designed to study possible accumulation of low MW lignin-derived products, showed no such accumulation. Recalcitrant carbohydrates like microcrystalline cellulose supported higher lignolytic activity than easily metabolized carbohydrates like cellobiose. An assay developed to distinguish between CO 2 evolved from lignin and carbohydrate substrates demonstrated no stoichiometric correlation between the metabolism of the two cosubstrates. The submerged fermentations with unlabeled liqnin are difficult to monitor since chemical assays do not give accurate and true results. Lignolytic efficiencies that allowed monitoring of such fermentations were defined. Degraded lignins were clearly superior to C. versicolor in all aspects of lignin degradation; A fumigatus brought about substantial demethoxylation and dehydroxylation, whereas C. versicolor degraded lignins closely resembled undegraded kraft lignin. There was a good agreement among the different indices of lignin degradation, namely, 14 CO evolution, OCH 3 loss, OH loss, and monomer and dimer yield after permanganate oxidation

  13. Structure of Thermobifida fusca DyP-type peroxidase and activity towards Kraft lignin and lignin model compounds.

    Science.gov (United States)

    Rahmanpour, Rahman; Rea, Dean; Jamshidi, Shirin; Fülöp, Vilmos; Bugg, Timothy D H

    2016-03-15

    A Dyp-type peroxidase enzyme from thermophilic cellulose degrader Thermobifida fusca (TfuDyP) was investigated for catalytic ability towards lignin oxidation. TfuDyP was characterised kinetically against a range of phenolic substrates, and a compound I reaction intermediate was observed via pre-steady state kinetic analysis at λmax 404 nm. TfuDyP showed reactivity towards Kraft lignin, and was found to oxidise a β-aryl ether lignin model compound, forming an oxidised dimer. A crystal structure of TfuDyP was determined, to 1.8 Å resolution, which was found to contain a diatomic oxygen ligand bound to the heme centre, positioned close to active site residues Asp-203 and Arg-315. The structure contains two channels providing access to the heme cofactor for organic substrates and hydrogen peroxide. Site-directed mutant D203A showed no activity towards phenolic substrates, but reduced activity towards ABTS, while mutant R315Q showed no activity towards phenolic substrates, nor ABTS. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Pilot study investigating ambient air toxics emissions near a Canadian kraft pulp and paper facility in Pictou County, Nova Scotia.

    Science.gov (United States)

    Hoffman, Emma; Guernsey, Judith R; Walker, Tony R; Kim, Jong Sung; Sherren, Kate; Andreou, Pantelis

    2017-09-01

    Air toxics are airborne pollutants known or suspected to cause cancer or other serious health effects, including certain volatile organic compounds (VOCs), prioritized by the US Environmental Protection Agency (EPA). While several EPA-designated air toxics are monitored at a subset of Canadian National Air Pollution Surveillance (NAPS) sites, Canada has no specific "air toxics" control priorities. Although pulp and paper (P&P) mills are major industrial emitters of air pollutants, few studies quantified the spectrum of air quality exposures. Moreover, most NAPS monitoring sites are in urban centers; in contrast, rural NAPS sites are sparse with few exposure risk records. The objective of this pilot study was to investigate prioritized air toxic ambient VOC concentrations using NAPS hourly emissions data from a rural Pictou, Nova Scotia Kraft P&P town to document concentration levels, and to determine whether these concentrations correlated with wind direction at the NAPS site (located southwest of the mill). Publicly accessible Environment and Climate Change Canada data (VOC concentrations [Granton NAPS ID: 31201] and local meteorological conditions [Caribou Point]) were examined using temporal (2006-2013) and spatial analytic methods. Results revealed several VOCs (1,3-butadiene, benzene, and carbon tetrachloride) routinely exceeded EPA air toxics-associated cancer risk thresholds. 1,3-Butadiene and tetrachloroethylene were significantly higher (p towns and contribute to poor health in nearby communities.

  15. Corporate Image and Public Health: An Analysis of the Philip Morris, Kraft, and Nestlé Websites

    Science.gov (United States)

    SMITH, ELIZABETH

    2012-01-01

    Companies need to maintain a good reputation to do business; however, companies in the infant formula, tobacco, and processed food industries have been identified as promoting disease. Such companies use their websites as a means of promulgating a positive public image, thereby potentially reducing the effectiveness of public health campaigns against the problems they perpetuate. The author examined documents from the websites of Philip Morris, Kraft, and Nestlé for issue framing and analyzed them using Benoit’s typology of corporate image repair strategies. All three companies defined the problems they were addressing strategically, minimizing their own responsibility and the consequences of their actions. They proposed solutions that were actions to be taken by others. They also associated themselves with public health organizations. Health advocates should recognize industry attempts to use relationships with health organizations as strategic image repair and reject industry efforts to position themselves as stakeholders in public health problems. Denormalizing industries that are disease vectors, not just their products, may be critical in realizing positive change. PMID:22420639

  16. Efeito da adição da antraquinona na pré-deslignificação com oxigênio no branqueamento e na qualidade da polpa kraft de eucalipto

    OpenAIRE

    Silva, Mariléa Pinto da

    2010-01-01

    A produção de polpa kraft vem se destacando mundialmente devido às grandes vantagens do processo. Alguns estudos têm mostrado que a adição da antraquinona em licores de cozimento kraft traz efeitos positivos ao processo como aumento do rendimento, redução do número kappa e ganhos nas propriedades físicas da polpa. O objetivo principal deste trabalho é avaliar o efeito das diferentes dosagens de antraquinona da pré-deslignificação com oxigênio no branqueamento pela seqüência ODualD(EP)D, na qu...

  17. A survey of present levels of radiocesium in Swedish pulp mill liquors and the implications for wood radiocesium transfer factors. Using Kraft mill liquors as an indicator of wood radiocesium contamination

    International Nuclear Information System (INIS)

    Ravila, A.; Holm, E.

    2000-01-01

    A survey was initiated to depict and compare the present activity levels in pulp mill liquors from various mill locations. The 137 Cs levels in pulp mill liquors were compared with the mill location and the deposition pattern of the Chernobyl fallout and nuclear weapons fallout. The large input of wood (about 2500 m 3 per day) to an average Nordic Kraft mill and the relatively long-term retention time for radiocesium in the Kraft mill recovery cycle enables representative sampling of substances directly related to the activity concentration in wood. (author)

  18. Reductive de-polymerization of kraft lignin for chemicals and fuels using formic acid as an in-situ hydrogen source.

    Science.gov (United States)

    Huang, Shanhua; Mahmood, Nubla; Tymchyshyn, Matthew; Yuan, Zhongshun; Xu, Chunbao Charles

    2014-11-01

    In this study, formic acid (FA) was employed as an in-situ hydrogen donor for the reductive de-polymerization of kraft lignin (KL). Under the optimum operating conditions, i.e., 300 °C, 1 h, 18.6 wt.% substrate concentration, 50/50 (v/v) water-ethanol medium with FA at a FA-to-lignin mass ratio of 0.7, KL (Mw∼10,000 g/mol) was effectively de-polymerized, producing de-polymerized lignin (DL, Mw 1270 g/mol) at a yield of ∼90 wt.% and polymerization of KL. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. QUALIDADE DA CELULOSE KRAFT-ANTRAQUINONA DE Eucalyptus dunnii PLANTADO EM CINCO ESPAÇAMENTOS EM RELAÇÃO AO Eucalyptus grandis E Eucalyptus saligna

    Directory of Open Access Journals (Sweden)

    Maria Cladis Mezzomo da Silva

    1997-12-01

    Full Text Available Este trabalho analisou o efeito de cinco espaçamentos de Eucalyptus dunnii (3 m x 1 m; 3 m x 1,5 m; 3 m x 2 m; 3 m x 3 m; 3 m x 4 m, para produção de celulose kraft-antraquinona, comparados com Eucalyptus grandis e Eucalyptus saligna (ambos no espaçamento 3 m x 2 m. Avaliaram-se a densidade básica e composição química da madeira original, analisando-se extrativos em diclorometano, pentosanas, lignina, solubilidade em NaOH8% e cinzas. Os cavacos foram submetidos a cozimento kraft-antraquinona com álcali ativo variando de 18,5 a 21% para obter um número kappa 17± 1,5; sulfidez a 8%, antraquinona base madeira 0,05%, relação licor/madeira 4:1, tempo até temperatura máxima 60 minutos, tempo à temperatura máxima 45 minutos. A celulose marrom resultante do cozimento kraft-antraquinona foi caracterizada e analisada em seus aspectos físico-químicos (rendimentos, rejeitos, número kappa, viscosidade intrínseca, alvura e solubilidade em NaOH5%. Uma parte desta sofreu refinação em moinho Jökro ao nível de 35°SR e, juntamente com a polpa não-refinada, foram submetidas a testes físico-mecânicos e óticos (resistência à tração, alongamento, estouro, rasgo, volume específico, alvura, resistência ao ar Gurley e ascensão capilar Klemm. O maior consumo de álcali ativo (20,5% ocorreu em espaçamento 3 m x 4 m, proporcionando maior degradação da polpa. Todos os espaçamentos caracterizados apresentaram viabilidade para a produção de celulose kraft-antraquinona, podendo proporcionar redução nos custos de produção de celulose, devido aos menores consumos apresentados de álcali ativo e madeira quando comparados com Eucalyptus grandis e Eucalyptus saligna. Os valores de extrativos e cinzas mostraram-se elevados para Eucalyptus dunnii, potencializando possíveis impactos em termos de incrustações e fechamento de circuito no processo fabril. Diante dos resultados obtidos, a celulose de Eucalyptus dunnii atende às exig

  20. Development of a strategy for energy efficiency improvement in a Kraft process based on systems interactions analysis

    Science.gov (United States)

    Mateos-Espejel, Enrique

    The objective of this thesis is to develop, validate, and apply a unified methodology for the energy efficiency improvement of a Kraft process that addresses globally the interactions of the various process systems that affect its energy performance. An implementation strategy is the final result. An operating Kraft pulping mill situated in Eastern Canada with a production of 700 adt/d of high-grade bleached pulp was the case study. The Pulp and Paper industry is Canada's premier industry. It is characterized by large thermal energy and water consumption. Rising energy costs and more stringent environmental regulations have led the industry to refocus its efforts toward identifying ways to improve energy and water conservation. Energy and water aspects are usually analyzed independently, but in reality they are strongly interconnected. Therefore, there is a need for an integrated methodology, which considers energy and water aspects, as well as the optimal utilization and production of the utilities. The methodology consists of four successive stages. The first stage is the base case definition. The development of a focused, reliable and representative model of an operating process is a prerequisite to the optimization and fine tuning of its energy performance. A four-pronged procedure has been developed: data gathering, master diagram, utilities systems analysis, and simulation. The computer simulation has been focused on the energy and water systems. The second stage corresponds to the benchmarking analysis. The benchmarking of the base case has the objectives of identifying the process inefficiencies and to establish guidelines for the development of effective enhancement measures. The studied process is evaluated by a comparison of its efficiency to the current practice of the industry and by the application of new energy and exergy content indicators. The minimum energy and water requirements of the process are also determined in this step. The third stage is

  1. A comprehensive program to develop correlations for the physical properties of Kraft black liquor. Interim report No. 2

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, A.L.

    1990-12-01

    Experimental effort for the program to evaluate physical properties of kraft black liquors is now proceeding well. Experimental work includes pulping, liquor analysis, lignin purification and characterization, vapor-liquid equilibria, heat capacity, heats of solution and combustion, and viscosity measurements. Measurement of thermal conductivity has not yet begun. Collection of the data necessary for development of generalized correlations is proceeding, but will require about two more years. The digester is operating very well. It is now possible to operate the digester as a closed, rotating reactor or as a batch reactor with liquor circulation. When operated with liquor circulation, temperatures within the chip bed can be monitored during cooking. Cooking is reproducible, and cooks are being performed to produce liquors for experimental studies. The digester could be further modified to permit us to conduct rapid exchange batch pulping or to permit us to simulate continuous pulping. Liquors to be used in experimental studies are concentrated in our large scale evaporator or in our small scale evaporator. The large scale evaporator is used to concentrate liquors to about 50% solids for storage and for use in studies requiring high solids liquors. The small scale evaporator is used for preparing final samples to as high as 85% solids and for measuring vapor-liquid equilibria. Liquors are now routinely analyzed to determine all components, except higher molecular weight organic acids and extractives. Lignin determination by uv-visible means has been improved. Lignin purification from black liquor has been improved and lignin molecular weights are determined routinely. Work on lignin molecular weight distribution is still not satisfactory, but recent developments holds promise.

  2. 40 CFR 430.03 - Best management practices (BMPs) for spent pulping liquor, soap, and turpentine management, spill...

    Science.gov (United States)

    2010-07-01

    ... gases from the cooking of softwoods by the kraft pulping process. Sometimes referred to as sulfate... professional judgment. [63 FR 18635, Apr. 15, 1998, as amended at 65 FR 46108, July 27, 2000] ...

  3. Process design and economics of on-site cellulase production on various carbon sources in a softwood-based ethanol plant.

    Science.gov (United States)

    Barta, Zsolt; Kovacs, Krisztina; Reczey, Kati; Zacchi, Guido

    2010-06-28

    On-site cellulase enzyme fermentation in a softwood-to-ethanol process, based on SO(2)-catalysed steam pretreatment followed by simultaneous saccharification and fermentation, was investigated from a techno-economic aspect using Aspen Plus© and Aspen Icarus Process Evaluator© softwares. The effect of varying the carbon source of enzyme fermentation, at constant protein and mycelium yields, was monitored through the whole process. Enzyme production step decreased the overall ethanol yield (270 L/dry tonne of raw material in the case of purchased enzymes) by 5-16 L/tonne. Capital cost was found to be the main cost contributor to enzyme fermentation, constituting to 60-78% of the enzyme production cost, which was in the range of 0.42-0.53 SEK/L ethanol. The lowest minimum ethanol selling prices (4.71 and 4.82 SEK/L) were obtained in those scenarios, where pretreated liquid fraction supplemented with molasses was used as carbon source. In some scenarios, on-site enzyme fermentation was found to be a feasible alternative.

  4. Excess heat from kraft pulp mills: Trade-offs between internal and external use in the case of Sweden-Part 1: Methodology

    International Nuclear Information System (INIS)

    Svensson, Inger-Lise; Joensson, Johanna; Berntsson, Thore; Moshfegh, Bahram

    2008-01-01

    Excess heat from a kraft pulp mill can be used either internally to increase the level of efficiency in the mill, or externally for example as district heating. This paper presents an approach to investigate the competition between external and internal use through modelling the pulp mill and an energy company (ECO) within the same system boundary. Three different sizes of ECOs with different district heating demands are studied. To investigate the competitiveness of using industrial excess heat as district heating compared with other heat production techniques, the option of investing in excess heat use is introduced, along with the possibility for the ECO to invest in biomass combined heat and power (CHP), waste CHP and natural gas combined cycle (NGCC). To evaluate the robustness of the model, alternative solutions are identified and will be used as a comparison to the optimal solutions. The model has been verified by comparing the results with previous studies concerning kraft pulp mills and with related studies regarding district heating and real ECOs. Finally, the approach presented in this part of the study will be used in the second part in order to investigate the trade-off between internal and external use of excess heat under different future energy market scenarios

  5. A combined acidification/PEO flocculation process to improve the lignin removal from the pre-hydrolysis liquor of kraft-based dissolving pulp production process.

    Science.gov (United States)

    Shi, Haiqiang; Fatehi, Pedram; Xiao, Huining; Ni, Yonghao

    2011-04-01

    The presence of lignin impairs the utilization of the hemicelluloses dissolved in the pre-hydrolysis liquor (PHL) of the kraft-based dissolving pulp production process. In this paper, a novel process was developed by combining the acidification and poly ethylene oxide (PEO) flocculation concepts to improve the lignin removal. The results showed that the lignin removal was improved by the addition of PEO to the acidified PHL, particularly at a low pH of 1.5. The main mechanisms involved are the lignin/PEO complex formation and the bridging of the formed complexes. This hypothesis was supported by the turbidity, FTIR and particle size measurements. Interestingly, the hemicelluloses removal from the acidification/PEO flocculation was marginal, which would be beneficial for the down-stream ethanol production from the PHL. Additionally, a process flow diagram was proposed that incorporates this new concept into the existing configuration of kraft-based dissolving pulp production process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. RE-UTILIZATION OF INORGANIC SOLID WASTE (LIME MUD AS FOREST ROAD STABILIZER FROM THE CHEMICAL RECOVERY PROCESS IN KRAFT PULP MILL

    Directory of Open Access Journals (Sweden)

    Habip Eroğlu

    2005-04-01

    Full Text Available Waste handling is a concern in all pulp and paper mills. Best available techniques for reducing waste is to minimize the generation of solid waste and/or reuse these materials, wherever practicable. One of the most important solid wastes is lime mud which is generated from the kraft pulping in its chemical recovery process. This paper explores the composition of lime mud resulting from the chemical recovery unite of kraft pulp mill and investigation of this waste for re-using beneficially on sub grade and pavement of forest road as a alternative disposal method. Lime mud obtained from the re-causticising process in SEKA pulp mill that utilizes wheat straw and reed as the principal raw material was supplied with % 47 water content and its chemical and physical characterisations was performed according to standard methods. Dried waste to environmental condition was mixed with certain amount to composite cement for using on pavement and sandy clay, loamy clay and clay soils for enriching forest road sub grade properties. In order to investigate the lime mud addition on pavement and sub grade properties necessary physical tests were performed. As a consequence this study reveals that while waste of lime mud causes environmental and economical problem with conventional disposal techniques and/or abandoning to environment, this waste can be used as good stabilisation materials on forest road sub-grade and pavement without any environmental problem.

  7. Excess heat from kraft pulp mills: Trade-offs between internal and external use in the case of Sweden-Part 2: Results for future energy market scenarios

    International Nuclear Information System (INIS)

    Joensson, Johanna; Svensson, Inger-Lise; Berntsson, Thore; Moshfegh, Bahram

    2008-01-01

    In this paper the trade-off between internal and external use of excess heat from a kraft pulp mill is investigated for four different future energy market scenarios. The work follows the methodology described in Svensson et al. [2008. Excess heat from kraft pulp mills: trade-offs between internal and external use in the case of Sweden-Part 1: methodology. Energy Policy, submitted for publication], where a systematic approach is proposed for investigating the potential for profitable excess heat cooperation. The trade-off is analyzed by economic optimization of an energy system model consisting of a pulp mill and an energy company (ECO). In the model, investments can be made, which increase the system's energy efficiency by utilization of the mill's excess heat, as well as investments that increase the electricity production. The results show that the trade-off depends on energy market prices, the district heating demand and the type of existing heat production. From an economic point of view, external use of the excess heat is preferred for all investigated energy market scenarios if the mill is studied together with an ECO with a small heat load. For the cases with medium or large district heating loads, the optimal use of excess heat varies with the energy market price scenarios. However, from a CO 2 emissions perspective, external use is preferred, giving the largest reduction of global emissions in most cases

  8. Characterization and genomic analysis of kraft lignin biodegradation by the beta-proteobacterium Cupriavidus basilensis B-8

    Directory of Open Access Journals (Sweden)

    Shi Yan

    2013-01-01

    Full Text Available Abstract Background Lignin materials are abundant and among the most important potential sources for biofuel production. Development of an efficient lignin degradation process has considerable potential for the production of a variety of chemicals, including bioethanol. However, lignin degradation using current methods is inefficient. Given their immense environmental adaptability and biochemical versatility, bacterial could be used as a valuable tool for the rapid degradation of lignin. Kraft lignin (KL is a polymer by-product of the pulp and paper industry resulting from alkaline sulfide treatment of lignocellulose, and it has been widely used for lignin-related studies. Results Beta-proteobacterium Cupriavidus basilensis B-8 isolated from erosive bamboo slips displayed substantial KL degradation capability. With initial concentrations of 0.5–6 g L-1, at least 31.3% KL could be degraded in 7 days. The maximum degradation rate was 44.4% at the initial concentration of 2 g L-1. The optimum pH and temperature for KL degradation were 7.0 and 30°C, respectively. Manganese peroxidase (MnP and laccase (Lac demonstrated their greatest level of activity, 1685.3 U L-1 and 815.6 U L-1, at the third and fourth days, respectively. Many small molecule intermediates were formed during the process of KL degradation, as determined using GC-MS analysis. In order to perform metabolic reconstruction of lignin degradation in this bacterium, a draft genome sequence for C. basilensis B-8 was generated. Genomic analysis focused on the catabolic potential of this bacterium against several lignin-derived compounds. These analyses together with sequence comparisons predicted the existence of three major metabolic pathways: β-ketoadipate, phenol degradation, and gentisate pathways. Conclusion These results confirmed the capability of C. basilensis B-8 to promote KL degradation. Whole genomic sequencing and systematic analysis of the C. basilensis B-8 genome

  9. Mechanical deconstruction of lignocellulose cell walls and their enzymatic saccharification

    Science.gov (United States)

    Ingrid C. Hoeger; Sandeep S. Nair; Arthur J. Ragauskas; Yulin Deng; Orlando J. Rojas; J.Y. Zhu

    2013-01-01

    Laboratory mechanical softwood pulps (MSP) and commercial bleached softwood kraft pulps (BSKP) were mechanically fibrillated by stone grinding with a SuperMassColloider®. The extent of fibrillation was evaluated by SEM imaging, water retention value (WRV) and cellulase adsorption. Both lignin content and mechanical treatment significantly affected deconstruction and...

  10. Wood pellets, what else? Greenhouse gas parity times of European electricity from wood pellets produced in the south-eastern United States using different softwood feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Hanssen, Steef V. [Radboud Univ., Nijmegen (Netherlands). Dept. of Environmental Science, Faculty of Science; Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences; Duden, Anna S. [Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences; Junginger, Martin [Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences; Dale, Virginia H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division, Center for BioEnergy Sustainability; van der Hilst, Floor [Utrecht Univ., Utrecht (The Netherlands). Copernicus Inst. of Sustainable Development, Faculty of Geosciences

    2016-12-29

    Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas (GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are reduced and on what timescale, we construct the GHG balance of wood-pellet electricity. This GHG balance consists of supply chain and combustion GHG emissions, carbon sequestration during biomass growth, and avoided GHG emissions through replacing fossil electricity. We investigate wood pellets from four softwood feedstock types: small roundwood, commercial thinnings, harvest residues, and mill residues. Per feedstock, the GHG balance of wood-pellet electricity is compared against those of alternative scenarios. Alternative scenarios are combinations of alternative fates of the feedstock material, such as in-forest decomposition, or the production of paper or wood panels like oriented strand board (OSB). Alternative scenario composition depends on feedstock type and local demand for this feedstock. Results indicate that the GHG balance of wood-pellet electricity equals that of alternative scenarios within 0 to 21 years (the GHG parity time), after which wood-pellet electricity has sustained climate benefits. Parity times increase by a maximum of twelve years when varying key variables (emissions associated with paper and panels, soil carbon increase via feedstock decomposition, wood-pellet electricity supply chain emissions) within maximum plausible ranges. Using commercial thinnings, harvest residues or mill residues as feedstock leads to the shortest GHG parity times (0-6 years) and fastest GHG benefits from wood-pellet electricity. Here, we find shorter GHG parity times than previous studies, for we use a novel approach that differentiates feedstocks and considers alternative scenarios based on (combinations of) alternative feedstock fates, rather than on alternative land

  11. Proceso de internacionalización de las empresas Compañía Licorera de Nicaragua, S.A. y Kraft Foods Nicaragua, S.A

    Directory of Open Access Journals (Sweden)

    Aurora Margarita Saravia

    2006-08-01

    Full Text Available AUNQUE NICARAGUA ES UN PAÍS SUBDESARROLLADO Y POBRE, fundamenta sus expectativas de crecimiento y desarrollo en la exportación, especialmente desde la firma de diferentes Tratados de Libre Comercio. Sin embargo, son pocas las empresas nacionales que han logrado competir con éxito en los mercados internacionales. Entre ellas, se encuentran la Compañía Licorera de Nicaragua, S.A. y Kraft Foods de Nicaragua, S.A. El éxito del proceso de internacionalización depende de muchos factores, incluyendo la decisión de aventurarse en el extranjero. El punto clave está en aprovechar las ventajas competitivas de cada empresa y enfocarlas para obtener productos y servicios de calidad que son los pilares del éxito. El éxito internacional de estas tres empresas se analiza en este trabajo para dar a conocer su experiencia

  12. Qualidade da celulose kraft-antraquinona de Eucalyptus dunnii plantado em cinco espaçamentos em relação ao Eucalyptus grandis e Eucalyptus saligna.

    Directory of Open Access Journals (Sweden)

    Giovanni Willer Ferreira

    2009-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Este trabalho analisou o efeito de cinco espaçamentos de Eucalyptus dunnii (3 m x 1 m; 3 m x 1,5 m; 3 m x 2 m; 3 m x 3 m; 3 m x 4 m, para produção de celulose kraft-antraquinona, comparados com Eucalyptus grandis e Eucalyptus saligna (ambos no espaçamento 3 m x 2 m. Avaliaram-se a densidade básica e composição química da madeira original, analisando-se extrativos em diclorometano, pentosanas, lignina, solubilidade em NaOH8% e cinzas. Os cavacos foram submetidos a cozimento kraft-antraquinona com álcali ativo variando de 18,5 a 21% para obter um número kappa 17± 1,5; sulfidez a 8%, antraquinona base madeira 0,05%, relação licor/madeira 4:1, tempo até temperatura máxima 60 minutos, tempo à temperatura máxima 45 minutos. A celulose marrom resultante do cozimento kraft-antraquinona foi caracterizada e analisada em seus aspectos físico-químicos (rendimentos, rejeitos, número kappa, viscosidade intrínseca, alvura e solubilidade em NaOH5%. Uma parte desta sofreu refinação em moinho Jökro ao nível de 35°SR e, juntamente com a polpa não-refinada, foram submetidas a testes físico-mecânicos e óticos (resistência à tração, alongamento, estouro, rasgo, volume específico, alvura, resistência ao ar Gurley e ascensão capilar Klemm. O maior consumo de álcali ativo (20,5% ocorreu em espaçamento 3 m x 4 m, proporcionando maior degradação da polpa. Todos os espaçamentos caracterizados apresentaram viabilidade para a produção de celulose kraft-antraquinona, podendo proporcionar redução nos custos de produção de celulose, devido aos menores consumos apresentados de álcali ativo e madeira quando comparados com Eucalyptus grandis e Eucalyptus saligna. Os valores de extrativos e cinzas mostraram-se elevados para Eucalyptus dunnii, potencializando possíveis impactos em termos de incrustações e fechamento de circuito no processo fabril. Diante dos resultados

  13. Removal of inhibitors from pre-hydrolysis liquor of kraft-based dissolving pulp production process using adsorption and flocculation processes.

    Science.gov (United States)

    Liu, Xin; Fatehi, Pedram; Ni, Yonghao

    2012-07-01

    A process for removing inhibitors from pre-hydrolysis liquor (PHL) of a kraft-based dissolving pulp production process by adsorption and flocculation, and the characteristics of this process were studied. In this process, industrially produced PHL was treated with unmodified and oxidized activated carbon as an absorbent and polydiallyldimethylammonium chloride (PDADMAC) as a flocculant. The overall removal of lignin and furfural in the developed process was 83.3% and 100%, respectively, while that of hemicelluloses was 32.7%. These results confirmed that the developed process can remove inhibitors from PHL prior to producing value-added products, e.g. ethanol and xylitol via fermentation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Fuld kraft frem

    DEFF Research Database (Denmark)

    Adler-Nissen, Rebecca

    2007-01-01

    Traktaten har fået et nyt navn, symbolerne er pillet ud, men i substansen er der sket meget få ændringer. Hele forhandlingsforløbet har haft ét formål: at få vedtaget traktaten uden at spørge de europæiske befolkninger....

  15. Bazı çam türlerinden kraft kağıt hamuru elde etme sürecinde sodyum borhidrür ilavesinin etkileri

    Directory of Open Access Journals (Sweden)

    Akın SARAÇBAŞI

    2016-12-01

    Full Text Available Bu araştırmada, kızılçam (Pinus brutia Ten. ve Monteri çamı (Pinus radiata D. Don. türlerinden toplam verim ve delignifikasyonu geliştirmek amacı ile alternatif bir Sodyum borhidrür (NaBH4-Kraft kâğıt hamuru elde etme yöntemi üzerinde çalışılmıştır. Delignifikasyon derecesi ve hamur verimi üzerinde reaksiyon koşullarının etkileri değerlendirilmiştir.Sonuçlar, sodyum borhidrür ilavesinin bilinen Kraft yöntemine göre her iki çam türünün hem verim hem de delignifikasyonunu geliştirmek için daha etkili olduğunu göstermektedir. Sodyum borhidrür (NaBH4-Kraft yönteminin, geleneksel Kraft yönteminin tek başına verdiği kappa numarası ve yüksek verim açısından, daha hızlı ve daha seçici olduğu düşünülmektedir. Ancak, kızılçam için en iyi Sodyum borhidrür (NaBH4-Kraft kâğıt hamuru üretim koşulu Aktif Alkali: %16, Sülfidite: %28, NaBH4 oranı: %0.5 iken, Monteri çamı için en iyi Sodyum borhidrür (NaBH4-Kraft kâğıt hamuru üretim koşulunun ise Aktif Alkali: %20, Sülfidite: %26, NaBH4 Oranı: %0.7 olduğu bulunmuştur.

  16. Qualidade da celulose kraft-antraquinona de Eucalyptus dunnii plantado em cinco espaçamentos em relação ao Eucalyptus grandis e Eucalyptus saligna.

    OpenAIRE

    Giovanni Willer Ferreira; Jorge Vieira Gonzaga; Celso Edmundo B. Foelkel; Teotônio Francisco de Assis; Edvins Ratnieks; Maria Cladis Mezzomo da Silva

    2009-01-01

    Este trabalho analisou o efeito de cinco espaçamentos de Eucalyptus dunnii (3 m x 1 m; 3 m x 1,5 m; 3 m x 2 m; 3 m x 3 m; 3 m x 4 m), para produção de celulose kraft-antraquinona, comparados com Eucalyptus grandis e Eucalyptus saligna (ambos no espaçamento 3 m x 2 m). Avaliaram-se a densidade básica e composição química da madeira original, analisando-se extrativos em diclorometano, pentosanas, lignina, solubilidade em NaOH8% e cinzas. Os cavacos foram submetidos a cozimento kraft-antraqu...

  17. Kraft pulping and ECF bleaching of Eucalyptus globulus pretreated by the white-rot fungus Ceriporiopsis subvermispora - doi: 10.4025/actascitechnol.v34i3.12410

    Directory of Open Access Journals (Sweden)

    Claudio Salazar

    2012-05-01

    Full Text Available Eucalyptus globulus wood chips were decayed by the lignin-degrading fungus Ceriporiopsis subvermispora as a pretreatment step before kraft pulping. Weight and component losses of wood after the biotreatment were the following: weight (5%, glucans (1.5%, xylans (4.3%, lignin (5.7% and extractives (57.5%. The residual amount of lignin (expressed by the kappa number in pulps from biotreated wood chips was lower than that of pulps from the undecayed control. Depending on the delignification degree, kraft biopulps presented similar or up to 4% increase in pulp yield and 20% less hexenuronic acids (HexA than control pulps. The extended delignification with O2 decreases approximately 50% of the kappa number of the pulps and increases brightness, but had no effect in HexA reduction. The bleaching steps with chlorine dioxide (D0ED1 sequence decreased the kappa number up to 97%, increased pulp brightness up to 84% ISO and decreased HexA amount up to 91%. The use of C. subvermispora in biopulping of E. globulus generated important benefits during the production of kraft pulps that are reflected in a high pulp yield, low residual lignin content, low HexA amount, high brightness and viscosity of the biopulps as compared with pulps produced from untreated wood chips.

  18. Structural Alterations of Lignins in Transgenic Poplars with Depressed Cinnamyl Alcohol Dehydrogenase or Caffeic Acid O-Methyltransferase Activity Have an Opposite Impact on the Efficiency of Industrial Kraft Pulping1

    Science.gov (United States)

    Lapierre, Catherine; Pollet, Brigitte; Petit-Conil, Michel; Toval, Gabriel; Romero, Javier; Pilate, Gilles; Leplé, Jean-Charles; Boerjan, Wout; Ferret, Valérie; De Nadai, Véronique; Jouanin, Lise

    1999-01-01

    We evaluated lignin profiles and pulping performances of 2-year-old transgenic poplar (Populus tremula × Populus alba) lines severely altered in the expression of caffeic acid/5-hydroxyferulic acid O-methyltransferase (COMT) or cinnamyl alcohol dehydrogenase (CAD). Transgenic poplars with CAD or COMT antisense constructs showed growth similar to control trees. CAD down-regulated poplars displayed a red coloration mainly in the outer xylem. A 90% lower COMT activity did not change lignin content but dramatically increased the frequency of guaiacyl units and resistant biphenyl linkages in lignin. This alteration severely lowered the efficiency of kraft pulping. The Klason lignin level of CAD-transformed poplars was slightly lower than that of the control. Whereas CAD down-regulation did not change the frequency of labile ether bonds or guaiacyl units in lignin, it increased the proportion of syringaldehyde and diarylpropane structures and, more importantly with regard to kraft pulping, of free phenolic groups in lignin. In the most depressed line, ASCAD21, a substantially higher content in free phenolic units facilitated lignin solubilization and fragmentation during kraft pulping. These results point the way to genetic modification of lignin structure to improve wood quality for the pulp industry. PMID:9880356

  19. Utilização de surfactantes, na polpação kraft de madeira de eucalipto, como auxiliar na remoção de extrativos lipofílicos Surfactant utilization in kraft pulping of eucalyptus wood to improve lipophilic extractives removal

    Directory of Open Access Journals (Sweden)

    Deusanilde de Jesus Silva

    2004-12-01

    Full Text Available Problemas de deposição de "pitch" em fábricas de celulose e de papel são atribuídos aos extrativos lipofílicos existentes na madeira. Uma das maneiras mais eficientes de controlar essa deposição é através da remoção de seus precursores do sistema, logo que possível, nas etapas de cozimento, lavagem da polpa marrom e pré-deslignificação com oxigênio. O uso de surfactantes como aditivos da polpação tem sido investigado, mas há grande deficiência de informações técnicas, e a aplicação industrial é, ainda, incipiente. A proposta deste trabalho foi analisar a viabilidade de minimizar a deposição de "pitch", intensificando a remoção de suas substâncias precursoras na etapa de polpação pelo uso de tensoativos sintéticos com propriedades umectantes e solubilizantes. Foram testados 20 princípios ativos de surfactantes em cozimento kraft convencional de madeira de eucalipto. Os resultados, alguns estatisticamente significativos, apontaram redução do teor de substâncias lipofílicas na polpa marrom. Foi observado que a remoção dos extrativos lipofílicos da madeira é afetada, inversamente, pelo teor de óxido de eteno na molécula do surfactante. Outros parâmetros de cozimento, como deslignificação, rendimento, teor de rejeitos e viscosidade da polpa, foram também avaliados.Extractives are pitch precursors and may decrease pulping efficiency and affect pulp quality. Probably, the most efficient way to minimize pitch problems is to remove their precursors from the system during cooking, pulp washing and oxygen delignification. Use of surfactants as pulping additives has been investigated but technical information is deficient and industrial application is very incipient. The objective of this study was to analyze the performance of different surfactants as additives for kraft pulping of Eucalyptus wood. Twenty surfactants with different basic chemical structures were used. The results demonstrated that

  20. Efeito dos sólidos dissolvidos da madeira na branqueabilidade e nas propriedades físico-mecânicas e ópticas de polpa kraft branqueada de eucalipto

    Directory of Open Access Journals (Sweden)

    Dalton Longue Júnior

    2012-03-01

    Full Text Available http://dx.doi.org/10.5902/198050985089Muitos estudos demonstram que o rendimento da polpação kraft pode ser melhorado pela readsorção de xilanas à polpa durante o cozimento, e o licor negro kraft contém fração significativa das xilanas da madeira, sendo uma importante fonte dessas macromoléculas. Porém, o efeito dessa técnica nas propriedades físico-mecânicas e ópticas de polpa branqueada de eucalipto, ainda não está bem esclarecido. Neste estudo foram produzidas polpas de eucalipto provenientes de cozimento kraft convencional, com diferentes adições de licor negro (0, 25, 50, 75 e 100 % v/v. Os cozimentos foram conduzidos até número kappa 17-18 e as polpas resultantes foram deslignificadas com oxigênio em condições fixas. O branqueamento foi realizado utilizando uma sequência DHT(EPDP até alvura final 92 % ISO. Em seguida as polpas foram refinadas num moinho PFI a diferentes níveis de revoluções (0, 500, 1.500, 3.000 e 6.000 e realizados testes de resistência ao rasgo, ao arrebentamento e à passagem de ar, alongamento, opacidade, densidade, volume específico aparente, capilaridade Klemm e índice de retenção de água (WRV. A eficiência e o ganho de alvura da pré-deslignificação com oxigênio foram ligeiramente prejudicados pela adição de licor negro ao cozimento kraft. A adição de 50 % de licor negro aos cozimentos resultou em polpas de pior branqueabilidade, sendo a demanda de cloro ativo aumentada em 5,3 kg/t celulose seca para obtenção de alvura 92 % ISO. As propriedades físico-mecânicas e ópticas das polpas kraft branqueadas não foram influenciadas, significativamente, pelo uso de licor negro no cozimento.

  1. Catalytic efficiency of natural and synthetic compounds used as laccase-mediators in oxidising veratryl alcohol and a kraft lignin, estimated by electrochemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Arzola, K. [Department of Microbiology and Cell Biology, Faculty of Pharmacy, University of La Laguna, 38206 La Laguna, Tenerife (Spain); Arevalo, M.C. [Department of Physical Chemistry, Faculty of Chemistry, University of La Laguna, 38206 La Laguna, Tenerife (Spain)], E-mail: carevalo@ull.es; Falcon, M.A. [Department of Microbiology and Cell Biology, Faculty of Pharmacy, University of La Laguna, 38206 La Laguna, Tenerife (Spain)], E-mail: mafalcon@ull.es

    2009-03-30

    The electrochemical properties of eighteen natural and synthetic compounds commonly used to expand the oxidative capacity of laccases were evaluated in an aqueous buffered medium using cyclic voltammetry. This clarifies which compounds fulfil the requisites to be considered as redox mediators or enhancers. Cyclic voltammetry was also applied as a rapid way to assess the catalytic efficiency (CE) of those compounds which oxidise a non-phenolic lignin model (veratryl alcohol, VA) and a kraft lignin (KL). With the exception of gallic acid and catechol, all assayed compounds were capable of oxidising VA with varying CE. However, only some of them were able to oxidise KL. Although the oxidised forms of HBT and acetovanillone were not electrochemically stable, their reduced forms were quickly regenerated in the presence of VA. They thus act as chemical catalysts. Importantly, HBT and HPI did not attack the KL via the same mechanism as in VA oxidation. Electrochemical evidence suggests that violuric acid oxidises both substrates by an electron transfer mechanism, unlike the other N-OH compounds HBT and HPI. Acetovanillone was found to be efficient in oxidising VA and KL, even better than the synthetic mediators TEMPO, violuric acid or ABTS. Most of the compounds produced a generalised increase in the oxidative charge of KL, probably attributed to chain reactions arising between the phenolic and non-phenolic components of this complex molecule.

  2. Catalytic efficiency of natural and synthetic compounds used as laccase-mediators in oxidising veratryl alcohol and a kraft lignin, estimated by electrochemical analysis

    International Nuclear Information System (INIS)

    Gonzalez Arzola, K.; Arevalo, M.C.; Falcon, M.A.

    2009-01-01

    The electrochemical properties of eighteen natural and synthetic compounds commonly used to expand the oxidative capacity of laccases were evaluated in an aqueous buffered medium using cyclic voltammetry. This clarifies which compounds fulfil the requisites to be considered as redox mediators or enhancers. Cyclic voltammetry was also applied as a rapid way to assess the catalytic efficiency (CE) of those compounds which oxidise a non-phenolic lignin model (veratryl alcohol, VA) and a kraft lignin (KL). With the exception of gallic acid and catechol, all assayed compounds were capable of oxidising VA with varying CE. However, only some of them were able to oxidise KL. Although the oxidised forms of HBT and acetovanillone were not electrochemically stable, their reduced forms were quickly regenerated in the presence of VA. They thus act as chemical catalysts. Importantly, HBT and HPI did not attack the KL via the same mechanism as in VA oxidation. Electrochemical evidence suggests that violuric acid oxidises both substrates by an electron transfer mechanism, unlike the other N-OH compounds HBT and HPI. Acetovanillone was found to be efficient in oxidising VA and KL, even better than the synthetic mediators TEMPO, violuric acid or ABTS. Most of the compounds produced a generalised increase in the oxidative charge of KL, probably attributed to chain reactions arising between the phenolic and non-phenolic components of this complex molecule

  3. Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process.

    Science.gov (United States)

    Ahsan, Laboni; Jahan, M Sarwar; Ni, Yonghao

    2014-03-01

    This work investigated the feasibility of recovering and concentrating sugars and acetic acid (HAc) from prehydrolysis liquor (PHL) of the kraft-based dissolving pulp process prior to fermentation of hemicellulosic sugars, by the combination of activated carbon adsorption, nanofiltration (NF) and reverse osmosis (RO) processes. To reduce the fouling PHL was subjected to adsorption on activated carbon, then the treated PHL (TPHL) passed through a nanofiltration (NF DK) membrane to retain the sugars, and the permeate of acetic acid rich solution was passed through a reverse osmosis membrane (RO SG). It was found that for NF process sugars were concentrated from 48 to 227g/L at a volume reduction factor (VRF) of 5 while 80 to 90% of acetic acid was permeated. For the reverse osmosis process, 68% of acetic acid retention was achieved at pH 4.3 and 500 psi pressure and the HAc concentration increased from 10 to 50g/L. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  4. Liquefaction of kraft lignin by hydrocracking with simultaneous use of a novel dual acid-base catalyst and a hydrogenation catalyst.

    Science.gov (United States)

    Wang, Jindong; Li, Wenzhi; Wang, Huizhen; Ma, Qiaozhi; Li, Song; Chang, Hou-Min; Jameel, Hasan

    2017-11-01

    In this study, a novel catalyst, S 2 O 8 2- -KNO 3 /TiO 2 , which has active acidic and basic sites, was prepared and used in lignin hydrocracking with a co-catalyst, Ru/C. Ru/C is an efficient hydrogenation catalyst and S 2 O 8 2- -KNO 3 /TiO 2 is a dual catalyst, which could efficiently degrade lignin. This catalytic hydrogenation system can reduce solid products to less than 1%, while giving a high liquid product yield of 93%. Catalytic hydrocracking of kraft lignin at 320°C for 6h gave 93% liquid product with 0.5% solid product. Most of this liquid product was soluble in petroleum ether (60% of 93%), which is a clear liquid and comprises mainly of monomeric and dimeric degradation products. These results demonstrated that the combination of the two catalysts is an efficient catalyst for liquefaction of lignin, with little char formation (∼1%). This concept has the potential to produce valuable chemicals and fuels from lignin under moderate conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Integration of a kraft pulping mill into a forest biorefinery: pre-extraction of hemicellulose by steam explosion versus steam treatment.

    Science.gov (United States)

    Martin-Sampedro, Raquel; Eugenio, Maria E; Moreno, Jassir A; Revilla, Esteban; Villar, Juan C

    2014-02-01

    Growing interest in alternative and renewable energy sources has brought increasing attention to the integration of a pulp mill into a forest biorefinery, where other products could be produced in addition to pulp. To achieve this goal, hemicelluloses were extracted, either by steam explosion or by steam treatment, from Eucalyptus globulus wood prior to pulping. The effects of both pre-treatments in the subsequent kraft pulping and paper strength were evaluated. Results showed a similar degree of hemicelluloses extraction with both options (32-67% of pentosans), which increased with the severity of the conditions applied. Although both pre-treatments increased delignification during pulping, steam explosion was significantly better: 12.9 kappa number vs 22.6 for similar steam unexploded pulps and 40.7 for control pulp. Finally, similar reductions in paper strength were found regardless of the type of treatment and conditions assayed, which is attributed to the increase of curled and kinked fibers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Simple Stirling engine as cogeneration unit in residential areas; Einfacher Stirling-Motor fuer die Waerme-Kraft-Kopplung (WKK) in kleinen Wohngebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Budliger, J.P.

    2000-07-01

    Free-piston Stirling engines have been recognized for long as an ideally suited unit for combined heat and power (CHP) production in homes. The considerably improved use of fossil fuel as compared to their separate production, the clean, external combustion process and low noise are major assets, favouring the use of this technology in residential areas. However, up to present, the complexity and correspondingly high cost of these units hampered their practical application. A new, simple concept has recently been devised, which can easily be controlled and operated according to demand. Cost may be reduced substantially as compared to presently known concepts, giving promise for their widespread use in residential homes, as well as in a variety of other applications. (orig.) [German] Freikolben-Stirling-Motoren sind ideale Aggregate fuer die Waerme-Kraft-Kopplung (WKK oder KWK) in kleineren Wohnhaeusern. Der Brennstoff kann wesentlich besser genutzt werden als bei getrennter Bereitung der benoetigten Heizwaerme und der elektrischen Energie. Die saubere, kontinuierliche aeussere Verbrennung und der geringe abgegebene Laerm stellen wichtige Bedingungen fuer einen erfolgreichen Einsatz solcher Systeme im Wohnbereich dar. Bisher verhinderten aber die Komplexitaet der verfuegbaren Systeme den praktischen Einsatz dieser Einheiten. Im Folgenden wird ein neues, einfaches Konzept vorgestellt, welches zuverlaessig funktioniert und auch unter Teillast, dem benoetigten Waermebedarf genau angepasst, betrieben werden kann. Die Herstellungskosten sind wesentlich geringer als bei den bisher bekannten Systemen, was ideale Voraussetzungen fuer deren verbreitete Anwendung im Haushalt, wie in vielfaeltigen anderen Einsatzgebieten darstellt. (orig.)

  7. KRAFT PULPING CHARACTERISTICS OF THREE MOROCCAN EUCALYPTI. PART 2. COMPARISON OF THE GUAIACYL FRACTION OF THE NATIVE LIGNINS BY A NOVEL METHOD

    Directory of Open Access Journals (Sweden)

    Ericka F. Alves,

    2012-02-01

    Full Text Available In Part 1 of this series it was observed that one of the eucalypti (EGC 39 was more reactive than the other two in kraft and soda-AQ (SAQ cooking. However, the lignin in EGC 39 contained equal or less syringyl (S units than the other two eucalypti. In the present research an attempt was made to compare the guaiacyl (G fraction of the three lignins. The approach was to use SAQ treatment to cleave β-O-4 bonds in dimeric units containing uncondensed guaiacyl A-rings (those rearranging to quinone methides. The coniferyl alcohol, vinylguaiacol and isoeugenol generated from β-O-4 cleavage are then trapped as dimers by ethylguaiacol that is included in the SAQ liquor. Research with sugar maple (Acer saccharum showed that the estimate of these structures (uncondensed G-β-O-4 by this approach was in close agreement with traditional but more tedious methods such as permanganate oxidation and 31P NMR. It was also shown that the lignin in the EGC 39 hybrid contained a higher concentration of uncondensed G-β-O-4 structures than the other two eucalypti lignins.

  8. IMPACT OF FURFURAL ON THE SUGAR ANALYSIS OF PRE-HYDROLYSIS LIQUOR OF KRAFT-BASED DISSOLVING PULP PRODUCTION PROCESS USING THE HPAEC TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Abrar Saeed

    2011-03-01

    Full Text Available 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.

  9. Influence of High Shear Dispersion on the Production of Cellulose Nanofibers by Ultrasound-Assisted TEMPO-Oxidation of Kraft Pulp

    Directory of Open Access Journals (Sweden)

    Claude Daneault

    2012-09-01

    Full Text Available Cellulose nanofibers can be produced using a combination of TEMPO, sodium bromide (NaBr and sodium hypochlorite, and mechanical dispersion. Recently, this process has been the subject of intensive investigation. However, studies on the aspects of mechanical treatment of this process remain marginal. The main objective of this study is to evaluate the high shear dispersion parameters (e.g., consistency, stator-rotor gap, recirculation rate and pH and determine their influences on nanocellulose production using ultrasound-assisted TEMPO-oxidation of Kraft pulp. All nanofiber gels produced in this study exhibited rheological behaviors known as shear thinning. From all the dispersion parameters, the following conditions were identified as optimal: 0.042 mm stator-rotor gap, 200 mL/min recycle rate, dispersion pH of 7 and a feed consistency of 2%. High quality cellulose gel could be produced under these conditions. This finding is surely of great interest for the pulp and paper industry.

  10. Effect of type of fungal culture, type of pellets and pH on the semi-continuous post-treatment of an anaerobically-pretreated weak black liquor from kraft pulp industry

    Energy Technology Data Exchange (ETDEWEB)

    Robledo-Narvaez, P. N.; Ortega-Clemente, L. A.; Ponce-Noyola, M. T.; Rinderknecht-Seijas, N. F.; Poggi-Varaldo, H. M.

    2009-07-01

    It is well known that fungi belonging to the Basidiomycetes (such as Trametes versicolor, Lentinus edodes, Phanerochaete chrysosporium) are microorganisms with a demonstrated capability of degrading lignin and its derivatives using a powerful and diverse group of enzymes. Because of these features, ligninolytic fungi have been used for the treatment or post-treatment of a variety of recalcitrant and toxic effluents, those of the Kraft industry among them. Yet, most of reported fungal treatments so far required the supplementation with glucose or other soluble carbohydrates, pH 4 to 4,5, and their effective performance was demonstrated only for short periods of operation time. (Author)

  11. UP-report. The power system. Basis of the Development platform. Power to Swedish Energy Agency's strategy work FOKUS; UP-rapport. Kraftsystemet. Underlag fraan Utvecklingsplattformen. Kraft till Energimyndighetens strategiarbete FOKUS

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    The report serves as input to to Swedish Energy Agency's strategies and priorities for research and innovation in the power system for the period 2011 - 2016. The report has been compiled by members of the development platform Kraft. This report provides background and circumstances for the power system theme, and proposed priorities and activities for future efforts in this area. The development platform has contributed with valuable experience and skills that enabled the Swedish Energy Agency to then develop a strategy that meets the needs of society and business.

  12. PENENTUAN KOMPOSISI OPTIMUM BUBURAN KERTAS KRAFT LINER 150 GSM MENGGUNAKAN METODE MIXTURE EXPERIMENT (Studi kasus: Pabrik Pulp & Paper PT.Z

    Directory of Open Access Journals (Sweden)

    Johnson Saragih

    2015-11-01

    Full Text Available Tujuan dari penelitian ini adalah bagaimana caranya memilih komposisi dari campuran buburan kertas sehingga posisi optimum dapat tercapai, dengan tercapainya komposisi optimum tersebut diharapkan dapat  meningkatkan kualitas kertas yang diproduksi.Adapun komposisi buburan kertas yang ingin dicapai adalah  konsistensi sebesar untuk campuran ,pada campuran satu, tingkat freeness sebesar pada campuran dua dan tingkat internal bonding sebesar   pada campuran tiga. Percobaan dilakukan dengan metoda mixture experiment untuk sampel percobaan buburan kertas sebanyak 500 gr. Titik percobaan dibangkitkan dengan software minitab sebanyak 14 titik percobaan.Adapun komposisi campuran yang optimal diperoleh untuk total campuran diperoleh sebesar 71.23 % ( 356.15 gr Waste Paper, 8.72% (43.55gr Pulp (NUKP, 3.54% (17.7 gr Air, 5.7%(28.5 gr Rosin, 3.29 % (16.4 gr Aluminium Sulfat ( Al2(SO43, dan 7.55 %(37.75gr Starch. Dengan komposisi tersebut akan dihasilkan produk yang memenuhi spesifikasi yang telah ditetapkan perusahaan. Berdasarkan pengukuran kapabilitas proses  campuran satu, pada kertas kraft liner 150 gsm di perusahaan  untuk tingkat konsistensi, adalah sebesar 0.47 dan setelah dilakukan percobaan yang optimal, berubah menjadi 1.11 berarti  terdapat peningkatan sebesar 136.7 %.Pada campuran dua untuk tingkat freeness adalah 0.45 berubah menjadi 1.14 berarti meningkat sebesar 153.3 %, sedangkan pada campuran tiga untuk tingkat internal bonding dari 0.55 berubah menjadi 1.15 berarti meningkat sebesar 109 %. Kata kunci: mixture experiment; konsistensi; freeness; internal bonding Abstract The aim of the research are how to choose composition from pulp paper mix, so that optimum position can be achieved, with the achievement of optimum composition, it can be expected to increase quality of paper production.While the pulp paper composition to achieve are consistency as big as for mixing on first mix, freeness level as big as on second mix and internal

  13. Preparation of silica-supported carbon by Kraft lignin pyrolysis, and its use in solid-phase extraction of fluoroquinolones from environmental waters

    International Nuclear Information System (INIS)

    Speltini, Andrea; Sturini, Michela; Maraschi, Federica; Mandelli, Elettra; Dondi, Daniele; Profumo, Antonella; Vadivel, Dhanalakshmi

    2016-01-01

    The article describes a carbon-based material for solid-phase extraction (SPE) of fluoroquinolones from waters. It was obtained by pyrolytic deposition of Kraft lignin (LG) on silica particles. Marbofloxacin (MAR) and enrofloxacin (ENR) were chosen as model contaminants. The material was prepared by first adsorbing LG onto silica microparticles, this followed by pyrolytic treatment at 1200 °C for 2 h. Silica-supported carbon was characterized by scanning electron microscopy, surface area measurement (by BET), thermogravimetric analysis, and electron paramagnetic resonance. The carbon-coated silica particles were then tested as a column packing for SPE of MAR and ENR from spiked tap and river waters. Quantitative adsorption was observed at pH values of ∼7.5 for both drugs. They were eluted with a 70:30 mixture of aqueous tetrabutylammonium hydroxide and acetonitrile and then quantified by HPLC coupled to fluorescence detection. Samples spiked with MAR and ENR in the range from 10 to 1000 ng·L"−"1 gave recoveries ranging from 70 to 116% (for n = 3). Good inter-day precision (with RSDs between 7 and 16%) was observed for 20–1000 ng·L"−"1 spikes, also in natural river water. Sample volumes up to 500 mL provided enrichment factors up to 125, and this makes this material useful for determination of the two drugs at environmentally significant levels which are as low as a few ng·L"−"1. The batch-to-batch reproducibility was verified for 3 preparations. The sorbent was successfully applied to the determination of these drugs in environmental waters. (author)

  14. Treatment of real industrial wastewaters through nano-TiO2 and nano-Fe2O3 photocatalysis: case study of mining and kraft pulp mill effluents.

    Science.gov (United States)

    Nogueira, V; Lopes, I; Rocha-Santos, T A P; Gonçalves, F; Pereira, R

    2018-06-01

    High quantities of industrial wastewaters containing a wide range of organic and inorganic pollutants are being directly discharged into the environment, sometimes without proper treatment. Nanotechnology has a tremendous potential improving the existing treatments or even develop new treatment solutions. In this study, nano-TiO 2 or nano-Fe 2 O 3 was used for the photocatalytic treatment of kraft pulp mill effluent and mining effluent. The experiments with the organic effluent lead to reduction percentages of 93.3%, 68.4% and 89.8%, for colour, aromatic compounds and chemical oxygen demand, respectively, when treated with nano-TiO 2 /H 2 O 2 /UV and nano-Fe 2 O 3 /H 2 O 2 /UV, at pH 3.0. Significant removal of metals from the mining effluent was recorded but only for Zn, Al and Cd, the highest removal attained with 1.0 g L -1 of nano-TiO 2 /UV and nano-Fe 2 O 3 /UV. Regarding the toxicity of the organic effluent to Vibrio fischeri, it was reduced with the treatments combining the oxidant and the catalyst. However, for the inorganic effluent, the best reduction was achieved using 1.0 g L -1 of catalyst. In fact, the increase in dose of the catalyst, especially for nano-TiO 2 , enhanced toxicity reduction. Our results have shown that the use of these NMs seemed to be more effective in the organic effluent than in metal-rich effluent.

  15. Evaluation of opportunities for heat integration of biomass-based Fischer–Tropsch crude production at Scandinavian kraft pulp and paper mill sites

    International Nuclear Information System (INIS)

    Ljungstedt, Hanna; Pettersson, Karin; Harvey, Simon

    2013-01-01

    This study investigates heat integrated production of FT (Fischer–Tropsch) crude, where excess heat from the FT crude plant is delivered to a typical Scandinavian pulp and paper mill that produces fine paper. The sizes of FT crude plants are quantified, when the amount of excess heat from the FT plant exactly matches the heating demand otherwise satisfied by the bark boiler at the mill, considering a number of development pathways at the mill, including various degrees of steam savings and biorefinery options, such as lignin extraction. Performance of integrated production is compared with that of an FT stand-alone plant on the basis of wood fuel-to-FT crude efficiency, GHG (greenhouse gas) emissions balances and FT crude production cost. The results show that there exists a heat integration opportunity for an FT crude plant ranging from 0 up to 350 MW (LHV) of wood fuel depending on the development pathway for the mill. The results indicate higher overall efficiency and a generally lower production cost for the heat integrated, co-located production. Heat integrated production has a larger potential to contribute to GHG emission mitigation, assuming a future generation of grid electricity emitting equal to or less than an NGCC (natural gas combined cycle) power plant. - Highlights: • We investigate opportunities for heat integrated FT crude production at a mill. • Typical kraft pulp and paper mills have a potential for heat integrated production. • We compare the heat integrated production with stand-alone FT crude production. • Higher efficiency and lower production cost for heat integrated production. • Reduction of GHG emissions is strongly dependent on grid electricity emissions

  16. Estratégia de análise da qualidade de madeira de Eucalyptus sp. para produção de celulose A laboratory technique to establish Eucalyptus sp. wood quality for kraft pulp production

    Directory of Open Access Journals (Sweden)

    José Lívio Gomide

    2004-06-01

    Full Text Available Estudou-se uma nova técnica laboratorial de análise de qualidade da madeira de Eucalyptus sp. para produção de polpa celulósica kraft. A técnica consiste em realizar, simultaneamente, quatro cozimentos de cavacos utilizando diferentes cargas de álcali ativo para estabelecer a característica de deslignificação da madeira. Pelo uso de equações de regressão, calcula-se o álcali ativo necessário para obter o número kappa desejado, o rendimento, a viscosidade e álcali consumido para o kappa objetivo. Os estudos estatísticos evidenciaram que uma única batelada de quatro cozimentos é suficiente, não sendo necessário realizar repetições.A new laboratory technique was tested to determine Eucalyptus sp. wood quality for kraft pulp production. This technique consists in performing four cooks simultaneously using different active alkali charges to establish the wood delignification characteristics. Based on regression equation it is possible to determine the alkali charge necessary to obtain a desired kappa number and the yield, viscosity and the alkali consumed for the target kappa. Statistical analysis demonstrated that a set of four cooks without replication is sufficient to determine the wood quality characteristics.

  17. [Influence of the cycle number in processing of cellulose from waste paper on its ability to hydrolysis by cellulases].

    Science.gov (United States)

    Morozova, V V; Semenova, M V; Rozhkova, A M; Kondrat'eva, E G; Okunev, O N; Bekkarevich, A O; Novozhilov, E V; Sinitsin, A P

    2010-01-01

    Hydrolytic ability of laboratory enzyme preparations from fungus of the Penicillium genus was investigated using kraft pulp from nonbleached softwood and bleached hardwood cellulose as substrates. The enzyme preparations were shown to efficiently hydrolyze both softwood and hardwood cellulose. The yields of glucose and reducing sugars were 24-36 g/l and 27-37 g/l from 100 g/l of dry substrate in 48 h, respectively, and depended on the number of substrate grinding cycles.

  18. Steam slaking of lime - kinetics and technology. New energy effective lime slaking technology in kraft pulping; Aangslaeckning av kalk - kinetik och teknik. Ny energieffektiv teknik foer slaeckning av mesakalk i sulfatmassaindustrin

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, Roland

    2008-06-15

    Lime stone is widely used in chemical recovery for regeneration of white liquor in kraft pulping. Slaked (hydrated) lime is used to convert (causticize) sodium carbonate into sodium hydroxide, whereby lime mud (calcium carbonate) precipitates from the solution. Lime mud is dried and reburned in a lime kiln, where burned lime (calcium oxide) is formed. The circle is closed when lime is slaked (hydrated) in green liquor in an exotherm reaction. Problems with traditional lime burning and slaking methods are that heat recovery is bad and heat is recovered at low temperatures. With the method described in this report there is potential to increase heat recovery in the causticizing plant, and to recover heat at higher temperatures. The forecasted method means that lime is slaked with water vapour, for example combined with an indirect heated lime mud drier and a lime kiln. This project is a follow-up to pilot tests performed in a specific machine equipment at year 2006. The target group is pulp and paper industry using the kraft process. The owner of this new project is Carnot AB and the project is performed inside the Vaermeforsk Program for Pulp and Paper Industry 2006-2008. Partners and advisers in project group have been KTH Energy Processes, CTH Energy and Environment, LTH Chemical Technology, SMA Mineral AB, and reference group from STORA Enso Skoghall, Sodra Cell, M-Real Husum and SCA Packaging Piteaa. The task in this stage has included market investigations and laboratory tests. Contacts have been made with suppliers, preliminary dimensioning of process equipment and budget offers are received. Economic calculations have been made out of the offers. The laboratory tests are done as an examination paper at KTH Energiprocesser on the reactivity of burned lime from kraft lime kiln when it is slaked with water vapour instead of green liquor. The vapour intended to be used is at atmospheric pressure or even down to 0,2 atm. Complementary addition to these laboratory

  19. EVALUATION OF LINERBOARD PROPERTIES FROM MALAYSIAN CULTIVATED KENAF SODA-ANTHRAQUINONE PULPS VERSUS COMMERCIAL PULPS

    OpenAIRE

    Ahmad Azizi Mossello; Jalaluddin Harun; Rushdan Ibrahim; Hossien Resalati; Seyed Rashid Fallah Shamsi; Paridah Md Tahir; Mohd Nor Mohad Yusoff

    2010-01-01

    Malaysian cultivated kenaf has been identified as a suitable raw material for linerboard production. This study examines the soda-antraquinone (soda-AQ) pulp of kenaf fibers versus old corrugated container (OCC) and unbleached softwood kraft pulps as the main sources for linerboard production. The results showed significant differences among the pulp properties. The unbleached kraft pulp with very high freeness required high beating to reach an optimized freeness and produced paper with the h...

  20. Combined heat and power generation - a problem of reimbursement? CHP systems still on the march; BHKW - nur eine Frage der angemessenen Verguetung? Kraft-Waerme-Kopplung weiter im Aufwind

    Energy Technology Data Exchange (ETDEWEB)

    Jost, H.

    1996-04-15

    Systems for combined heat and power generation were a widely discussed issue in 1995. On the one hand, an ecological assessment was made by a study of the Eduard-Pestel-Institut fuer Systemforschung, Hanover. On the other hand, the problem of reimbursement for electricity supplied to the public grid is still unsolved. (orig.) [Deutsch] Anlagen zur gekoppelten Erzeugung von Strom (Kraft) und Waerme (KWK) waren im Jahr 1995 Gegenstand einer intensiven Diskussion. Zum einen hat eine Diskussion zur oekologischen Bewertung von KWK-Anlagen stattgefunden, die im wesentlichen von einer Studie des Eduard-Pestel-Instituts fuer Systemforschung in Hannover angestossen wurde. Zum anderen sind die Verguetungen fuer KWK-Strom in das oeffentliche Netz nach wie vor umstritten. (orig.)

  1. Avaliação dos resíduos de uma serraria para a produção de celulose kraft

    Directory of Open Access Journals (Sweden)

    Lucas Cândido Barbosa

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814589As indústrias de base florestal apresentam baixo rendimento e geram grande quantidade de resíduos, especialmente as indústrias de transformação primária como, por exemplo, as serrarias. No Brasil, estão sendo criadas iniciativas para aliar a utilização desses resíduos à produção de celulose. Dentro deste propósito, o presente trabalho teve como objetivos avaliar o rendimento de uma serraria de médio porte localizada no município de Rio Grande, RS, e promover análises físico-químicas dos resíduos gerados na etapa de desdobro. Foram utilizadas 20 toras de Pinus elliottii, divididas em duas classes diamétricas. Os resíduos, com exceção da serragem, coletados para análises, encontravam-se dispostos no pátio da empresa, na forma de cavacos. As seguintes propriedades físico-químicas dos cavacos foram analisadas: densidade básica, teor de extrativos solúvel em acetona, grupos acetilas, lignina solúvel e insolúvel em ácido (lignina Klason, grupos urônicos e carboidratos. Como principais resultados verificou-se um ligeiro aumento do rendimento em madeira serrada das madeiras de maiores diâmetros em relação às de menores diâmetros. Das análises físico-químicas foram obtidos os seguintes resultados: densidade básica de 0,402 g/cm³, teor de celulose de 37,42% e de 24,37% para hemiceluloses, lignina Klason de 26,75% e teor de extrativos de 3,80%. Concluiu-se, nesse estudo, que o baixo rendimento da serraria foi devido à falta de uma classificação diamétrica e diagramas de cortes apropriados para as toras, o que resulta em maior perda de madeira na forma de resíduos. Em relação às características química e física dos resíduos madeireiros, os resultados mostraram-se dentro dos padrões de qualidade da madeira utilizada para a produção de celulose kraft de fibra longa e, em algumas situações, apresentando vantagens em relação às madeiras mais jovens usualmente

  2. Hygroscopic slaking of lime with steam or humid air. New energy effective lime slaking technology in kraft pulping; Hygroskopisk slaeckning av kalk med aanga eller fuktig luft. Ny energieffektiv teknik foer slaeckning av mesakalk i sulfatmassaindustrin

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, Roland

    2005-12-15

    Lime stone is widely used in chemical recovery for regeneration of white liquor in kraft pulping. Slaked (hydrated) lime is used to convert (causticize) sodium carbonate into sodium hydroxide, whereby lime mud (calcium carbonate) precipitates from the solution. Lime mud is dried and reburned in a lime kiln, where burned lime (calcium oxide) is formed. The circle is closed when lime is slaked (hydrated) in green liquor in an exotherm reaction. Problems with traditional slaking method is that heat is recovered at low temperatures. With the method described in this report there is potential to increase heat recovery in the causticizing plant. The forecasted method means that lime is slaked with steam or humid air, for example combined with a lime mud drier and a lime kiln. The task has included slaking of burned lime with steam or humid hot air, on purpose to test a specific machine equipment in pilote scale, and to investigate temperatures and hydratization rates able to reach. Also the lime slaked with steam/humid air should be compared with burned lime slaked in green liquor when green liquor is causticized, and to investigate the dewatering properties of formed lime mud. The target group is pulp and paper industry using the kraft process. The tests have been performed at SMA Svenska Mineral AB plant (lime burning) at Sandarne Sweden in years 2004-2005. Hydrated lime of varying slaking rates has been produced at temperatures up to 270 deg C. Caustizicing being performed show that dewatering properties of lime mud formed is quite up to the standard of lime mud from burned lime slaked in green liquor. The apprehension, that the hygroscopic slaked lime should result in lime mud difficult to dewater, has not become true. Important experiences have come out which could be used as a base in further investigations.

  3. Xylanases of marine fungi of potential use for biobleaching of paper pulp

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Muraleedharan, U.; Gaud, V.R.; Mishra, R.

    isolates obtained from marine habitat showed alkaline xylanase activity. The crude enzyme from NIOCC isolate # 3 (Aspergillus niger) with high xylanase activity, cellulase-free and unique properties containing 580 U L-1 of xylanase, could bring about...

  4. Caracterização tecnológica, para produção de celulose, da nova geração de clones de Eucalyptus do Brasil Technological characterization of the new generation of Eucalyptus clones in Brazil for kraft pulp production

    Directory of Open Access Journals (Sweden)

    José Lívio Gomide

    2005-02-01

    Full Text Available Foram analisados clones de Eucalyptus de última geração, pertencentes às principais empresas brasileiras de celulose. Os estudos consistiram numa caracterização tecnológica detalhada da qualidade das madeiras utilizadas no processamento fabril das empresas. Foram realizadas análise químicas detalhadas das madeiras e cozimentos kraft, simulando-se uma das modernas técnica de digestor contínuo. Os resultados indicaram a alta qualidade dos clones de Eucalyptus atualmente plantados no Brasil para produção de celulose.Last generation of Eucalyptus clones pulped by the main Brazilian kraft pulp mills were used for this study. Detailed chemical analysis of the woods were carried out to establish the wood quality. Laboratory simulation of a modern continuous digester technique was used for pulp production. Results demonstrated the high quality of Eucalyptus clones wood that are being planted in Brazil for kraft pulp production.

  5. Integrated power-heat-cold-coupling by switchable Stirling-Vuilleumier-Hybrid-Machines; Integrierte Kraft-Waerme-Kaelte-Kopplung durch umschaltbare Stirling-Vuilleumier-Hybrid-Maschinen

    Energy Technology Data Exchange (ETDEWEB)

    Kuehl, Hans-Detlev [Technische Univ. Dortmund (Germany). Lehrstuhl fuer Thermodynamik

    2017-07-01

    . Dieser so entstandene ''Hybrid''-Prozess zeichnet sich nach wie vor durch eine - gegenueber dem Stirling-Modus lediglich leicht verringerte - mechanische Leistungsabgabe aus, zusaetzlich jedoch auch durch eine theoretisch zu dieser betragsmaessig gleichen, ueber den Arbeitszylinder bei ''kalter'' Temperatur aufgenommene Kaelteleistung. Er stellt somit ein integriertes System zur Kraft-Waerme-Kaelte-Kopplung dar, das durch einen einzigen thermodynamischen Prozess realisierbar ist. Schaltet man diesem Prozess im warmen Temperaturbereich zusaetzlich einen weiteren, auf der Rueckseite des Arbeitskolbens liegenden Zylinderraum zu, so dass ersterer zu einem zweiten, doppelseitig wirkenden Verdraengerkolben wird, so erhaelt man schliesslich den als thermisch angetriebene Waermepumpe bzw. Kaeltemaschine bekannten Vuilleumier-Prozess, der im Idealfall keine mechanische Leistung abgibt oder aufnimmt. Am Lehrstuhl fuer Thermodynamik der TU Dortmund wurde in einem mittlerweile abgeschlossenen, von der DFG gefoerderten Forschungsprojekt eine Versuchsmaschine entwickelt und vermessen, die sich zwischen den drei beschriebenen Prozessen umschalten und so wechselnden Strom-, Waerme- und Kaeltebedarfssituationen anpassen laesst. Dabei wurde zur Reduktion des experimentellen Aufwandes eine aehnlichkeitstheoretische Skalierung unter Konstanthaltung aller fuer den internen Gaskreisprozess relevanten dimensionslosen Kennzahlen durchgefuehrt. Die in diesem Beitrag vorgestellten experimentellen Ergebnisse beduerfen deshalb zwar einer Korrektur wegen einiger externer, nicht korrekt skalierbarer Reibungs- und Isolationsverluste, belegen aber dennoch, dass die Realisierung derart umschaltbarer Systeme zur dezentralen, bedarfsorientierten Energieversorgung von Gebaeuden in einer praxisgerechten Baugroesse und Leistungsklasse moeglich ist. Bei koordiniertem Betrieb einer groesseren Zahl solcher Systeme - z. B. ueber Rundsteuerungen oder netzlastabhaengige

  6. UTILIZAÇÃO DE MISTURAS DE CAVACOS INDUSTRIAIS COM RESÍDUOS DE SERRARIA PROVENIENTES DE MADEIRAS DE Eucalyptus grandis DE DIFERENTES IDADES PARA PRODUÇÃO DE PASTA KRAFT

    Directory of Open Access Journals (Sweden)

    Angelina Maron

    2004-01-01

    Full Text Available Este trabalho estuda a viabilidade técnica do uso conjunto de resíduos de serraria (costaneiras dentre outros e topos de árvores de Eucalyptus grandis com 15 anos de idade, destinadas à produção de madeira sólida, com madeira de árvores de plantio industrial, com 7 anos de idade, destinadas à produção de pasta kraft. São apresentados modelos úteis à realização de estimativas de alturas total e comercial e de volumes de madeira comercial e adequadas para serraria, todos baseados no DAP. São fornecidos dados anatômicos, de densidade básica e de composição química de misturas desses tipos de materiais. Mostra-se que é tecnicamente viável realizar deslignificações kraft com misturas contendo madeira comercial de Eucalyptus grandis 7 anos com resíduo de serraria ou topos de árvores. A deslignificação kraft de resíduos de serraria resulta em perda rápida de rendimento, mas a pasta produzida sob as mesmas condições apresenta número Kappa menor que a de Eucalyptus grandis com 7 anos. A deslignificação de topos de árvores resulta em perda de rendimento bruto, mas o consumo específico de madeira é menor. Conforme aumenta a madeira de topo nas misturas, ocorre um aumento na densidade básica, o comprimento médio das fibras fica praticamente o mesmo e um pequeno aumento no teor de lignina; há diminuição nos extrativos em etanol, em água quente e na solubilidade em NaOH 1%. Diminui um pouco o rendimento bruto em pasta, mas praticamente não afeta o número Kappa, caindo sensivelmente o consumo específico de madeira. Com o aumento de madeira de resíduo de serraria das árvores nas misturas, praticamente não há efeito sobre a densidade básica, mas o comprimento médio das fibras aumenta, ocorrendo também um pequeno aumento no teor de lignina. Os extrativos em etanol, em água quente e na solubilidade em NaOH 1% diminuem. O rendimento bruto em pasta cai um pouco, mas com uma queda sensível no número Kappa

  7. Characterisation and application of NovaFiber lignin

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Snijder, M.H.B.; Kranenbarg, A.; Keijsers, E.R.P.; Jong, de E.; Stigsson, L.L.

    2004-01-01

    Sulphur-free lignin coming from a novel alkaline-pulping process called NovaFiber, which has been developed by KIRAM AB, has been characterised and evaluated for potential applications. A Kraft lignin has been used for comparison. Considering the characterisation results of a NovaFiber softwood and

  8. Hygroscopic slaking of lime with steam or humid air. New energy effective lime slaking technology in kraft pulping; Hygroskopisk slaeckning av kalk med aanga eller fuktig luft. Ny energieffektiv teknik foer slaeckning av mesakalk i sulfatmassaindustrin

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, Roland

    2003-07-15

    Lime stone is widely used in chemical recovery for regeneration of white liquor in kraft pulping. Slaked (hydrated) lime is used to convert (causticize) sodium carbonate into sodium hydroxide, whereby lime mud (calcium carbonate) precipitates from the solution. Lime mud is dried and reburned in a lime kiln, where burned lime (calcium oxide) is formed. The circle is closed when lime is slaked (hydrated) in green liquor in an exotherm reaction. Problems with traditional slaking method is that heat is recovered at low temperatures. With the method described in this report there is potential to increase heat recovery in the causticizing plant. The forecasted method means that lime is slaked with steam or humid air, for example combined with a lime mud drier and a lime kiln. The task has included slaking of burned lime with steam or humid hot air, on purpose to test a specific machine equipment in pilote scale, and to investigate temperatures and hydratization rates able to reach. Also the lime slaked with steam/humid air should be compared with burned lime slaked in green liquor when green liquor is causticized, and to investigate the dewatering properties of formed lime mud. The target group is pulp and paper industry using the kraft process. The tests have been performed at SMA Svenska Mineral AB plant (lime burning) at Sandarne Sweden in years 2004-2005. Project owner has been the Swedish company Torkapparater AB, and the project is performed inside the 'Vaermeforsk Program for Pulp and Paper Industry 2004-2005'. Other partners, besides SMA Svenska Mineral AB, has been Stora Enso Skoghalls Bruk, Carnot AB, AaF Process AB and KTH Energiprocesser. Hydrated lime of varying slaking rates has been produced at temperatures up to 270 deg C. Caustizicing being performed show that dewatering properties of lime mud formed is quite up to the standard of lime mud from burned lime slaked in green liquor. The apprehension, that the hygroscopic slaked lime should result

  9. Quality drying of softwood lumber : guidebook - checklist

    Science.gov (United States)

    M. R. Milota; J. D. Danielson; R. S. Boone; D. W. Huber

    The IMPROVE Lumber Drying Program is intended to increase awareness of the lumber drying system as a critical component in the manufacture of quality lumber. One objective of the program is to provide easy-to-use tools that a kiln operator can use to maintain an efficient kiln operation and therefore contribute to lumber drying quality. This report is one component of...

  10. THE FUNGAL ABILITY FOR BIOBLEACHING/BIOPULPING/BIOREMEDIATION OF LIGNIN-LIKE COMPOUNDS OF AGRO-INDUSTRIAL RAW MATERIAL

    Directory of Open Access Journals (Sweden)

    Ana Maria Queijeiro López

    Full Text Available Lignin is present in plant cell secondary wall, associated to carbohydrates preventing their efficient hydrolysis, and cellulose pulp manufacture basically consists in breaking down the middle lamella of plant cells, individualizing fibers such as cellulose from the other biopolymers. Different levels of lignocellulose are found in plant residues and they can be decomposed by extracellular fungal lignin modifying enzymes, used as a tool to reduce waste materials in contaminated soils and effluents. In the paper mill industries, for instance, they are a suitable or complementary alternative to the traditional methods of pulping/bleaching, contributing to improve paper strength as well as to reduce the pitch content, the quantity of chemicals and the consume of electrical energy. The aim of this review was to describe the fungal degradation of lignocellulosic like-material, the non-specific enzymatic aspects of the attack of wood and agricultural wastes, the fungal ability for biosorption and bioconversion, and its applications in the pulp/paper industry and bioremediation.

  11. Eucalyptus kraft pulp production: Thermogravimetry monitoring

    International Nuclear Information System (INIS)

    Barneto, Agustin G.; Vila, Carlos; Ariza, Jose

    2011-01-01

    Highlights: → Thermogravimetric analysis can be used to monitor the pulping process in a pulp mill. → ECF bleaching process affects the crystalline cellulose volatilization. → The fibre size has an influence on composition and thermal behavior of pulp. - Abstract: Under oxidative environment the thermal degradation of lignocellulosic materials like wood or pulp is sensitive to slight composition changes. For this, in order to complement the chemical and X-ray diffraction results, thermogravimetric analyses (TGA) were used to monitor pulp production in a modern pulp mill. Runs were carried out on crude, oxygen delignified and bleached pulps from three eucalyptus woods from different species and geographical origins. Moreover, with the modeling of thermogravimetric data, it was possible to obtain an approximate composition of samples which includes crystalline and amorphous cellulose. TGA results show that pulping has an intensive effect on bulk lignin and hemicellulose, but it has limited influence on the removal of these substances when they are linked to cellulose microfibril. The stages of oxygen delignification and bleaching, based in chlorine dioxide and hydrogen peroxide, increase the crystalline cellulose volatilization rate. These changes are compatible with a more crystalline microfibril. The influence of the fibre size on pulp composition, crystallinity and thermal degradation behavior was observed.

  12. Wind power; Die Kraft der Winde

    Energy Technology Data Exchange (ETDEWEB)

    Mardo, Dietrich

    2009-10-30

    Wind power plants are probably only one pillar of the bridge that is taking us into an energy future still unimaginable to us. They are extremely cost-intensive and bulky and they spoil our landscapes. Their patronage by political leaders is understandable considering our excessive dependence on oil and gas. True energy autonomy is currently still a utopian dream for a country as poor in resources as Germany. On the other hand, to reach Utopia you have to build bridges there. Seen this way all currently available types of renewable energy represent bridge technologies whose realisation is imperative.

  13. Fibre volume losses of eight softwood clearfell harvesting systems in ...

    African Journals Online (AJOL)

    Eight treatments were examined: four terminated with merchandising at roadside landing and four at erchandising yards. Within the treatments, felling was either motor-manual or mechanised and compartments were classed by average compartment tree size (less than or greater than 1 m3). Total wood utilisation was found ...

  14. Fate of triazoles in softwood upon environmental exposure.

    Science.gov (United States)

    Kukowski, Klara; Martinská, Veronika; Sedgeman, Carl A; Kuplic, Paige; Kozliak, Evguenii I; Fisher, Stephen; Kubátová, Alena

    2017-10-01

    Determining the fate of preservatives in commercial wood products is essential to minimize their losses and improve protective impregnation techniques. The fate of triazole fungicides in ponderosa pine wood was investigated in both outdoor and controlled-environment experiments using a representative triazole, tebuconazole (TAZ), which was accompanied by propiconazole (PAZ) in selected experiments. The study was designed to mimic industrial settings used in window frame manufacturing. To investigate the TAZ fate in detail, loosely and strongly bound fractions were differentiated using a multi-step extraction. The loosely bound TAZ fraction extracted through two sonications accounted for 85± 5% of the total TAZ, while the strongly bound TAZ was extracted only with an exhaustive Soxhlet extraction and corresponded to the remaining 15± 5%. A significant fraction (∼80%) of the original TAZ remained in the wood despite a six-month exposure to harsh environmental conditions, maintaining wood preservation and assuring minimal environmental impact. Depletion of loosely bound TAZ was observed from cross-sectional surfaces when exposed to rain, high humidity and sunlight. Water leaching was deemed to be the major route leading to triazole losses from wood. Leaching rate was found to be slightly higher for TAZ than for PAZ. The contribution of bio-, photo- and thermal degradation of triazoles was negligible as both PAZ and TAZ sorbed in wood remained intact. Triazole evaporation was also found to be minor at the moderate temperature (20-25 °C) recorded throughout the outdoor study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Clearwood quality and softwood lumber prices: what's the real premium?

    Science.gov (United States)

    Thomas R. Waggener; Roger D. Fight

    1999-01-01

    Diminishing quantities of appearance grade lumber and rising price premiums for it have accompanied the transition from old-growth to young-growth timber. The price premiums for better grades are an incentive for producers to undertake investments to increase the yield of those higher valued products. Price premiums, however, are also an incentive for users to...

  16. Experimental evaluation of mechanical properties of softwood using acoustic methods

    Czech Academy of Sciences Publication Activity Database

    Tippner, J.; Hrivnák, J.; Kloiber, Michal

    2016-01-01

    Roč. 11, č. 1 (2016), s. 503-518 ISSN 1930-2126 R&D Projects: GA MK(CZ) DF11P01OVV001 Keywords : non destructive testing * Norway spruce * Scots pine * Silver fir * sound speed * strength * stress wave Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 1.321, year: 2016 http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_11_1_503_Tippner_Mechanical_Properties_Acoustic_Methods/4018

  17. HEATING CHARACTERISTICS OF SOFTWOODS IN A HIGH FREQUENCY FIELD

    Directory of Open Access Journals (Sweden)

    Ciprian LĂZĂRESCU

    2012-12-01

    Full Text Available The research aimed to establish whetherdielectric heating at radio frequencies might be afeasible option for phytosanitation of green softwoodboards. Results are presented for two softwoodspecies, namely, lodgepole pine (Pinus contorta andwestern red cedar (Thujaplicata Donn., and forsingle-specimen testing configurations with a crosssection of 40x90mm surrounded on three sides bysimilar cross-section kiln dried boards. In terms ofdielectric properties, red cedar is nature "designed" toabsorb more easily the dielectric fields. Heating rateswere not correlated with moisture content for neitherspecies investigated thus underlining the versatility ofRF-heating that allows simultaneous rise oftemperature within dry and wet areas. Convectionlosses through air contact may reduce the averageheating rate of the shell by about 40%.

  18. Two dimensional finite element heat transfer models for softwood

    Science.gov (United States)

    Hongmei Gu; John F. Hunt

    2004-01-01

    The anisotropy of wood creates a complex problem for solving heat and mass transfer problems that require analyses be based on fundamental material properties of the wood structure. Most heat transfer models use average thermal properties across either the radial or tangential directions and have not differentiated the effects of cellular alignment, earlywood/latewood...

  19. A South African softwood sawtimber supply chain case study ...

    African Journals Online (AJOL)

    Supply chain management principles were analysed by investigating the effects of smaller-scale and incremental interventions in a forest-to-mill value chain on financial returns and forest resource use in an Eastern Cape case study area. Three previous studies provided input by determining fibre balances, a terrain factor, ...

  20. Programmable calculator programs to solve softwood volume and value equations.

    Science.gov (United States)

    Janet K. Ayer. Sachet

    1982-01-01

    This paper presents product value and product volume equations as programs for handheld calculators. These tree equations are for inland Douglas-fir, young-growth Douglas-fir, western white pine, ponderosa pine, and western larch. Operating instructions and an example are included.

  1. INDUSTRIAL EVALUATION OF RE-DRY STRATEGY FOR SOFTWOOD LUMBER

    OpenAIRE

    Elustondo, Diego; Avramidis, Stavros

    2005-01-01

    This paper presents an experimental evaluation of the first commercial scale dry-sort-redry (DSRD) strategy for drying of 2x4 Pacific coast hemlock (PCH) lumber. The DSRD strategy is a methodology designed to reduce final moisture content variability in kiln dried lumber by complementing conventional drying with radio frequency vacuum (RFV) drying technology. The strategy′s objective is to avoid producing over-dried lumber in conventional drying by setting the target moisture content to...

  2. An assessment of the industrial markets for softwood clearwood lumber.

    Science.gov (United States)

    Ivan L. Eastin; Christine L. Lane; Roger D. Fight; Jamie Barbour

    1998-01-01

    The purpose of this project was to assess market opportunities for second growth clearwood lumber by identifying industry segments that currently utilize clearwood lumber and determining whether alternative markets will continue to exist for clearwood lumber produced from intensively managed forests in the Pacific Northwest. A survey of industrial lumber...

  3. 19 CFR 12.142 - Entry of softwood lumber and softwood lumber products from any country into the United States.

    Science.gov (United States)

    2010-04-01

    ... purposes of paragraph (c)(1) of this section, the following definitions apply: (A) F.O.B. The term “F.O.B... Tariff Act of 1930, as amended (19 U.S.C. 1202 et seq.); and (B) To the best of the person's knowledge and belief: (1) The export price provided is determined in accordance with the definition set forth in...

  4. Electric power in the competitive market - Investing capital for cleaner energy generation still a rewarding business? New perspectives for electrical energy efficiency improvement, the cogeneration technology, and renewable energy generation; Strom im Wettbewerb - Lohnen sich Investitionen in saubere Energien noch? Neue Perspektiven fuer effiziente Stromnutzung, Kraft-Waerme-Kopplung und Erneuerbare Energien. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    Schwanhold, E. [comp.

    2000-07-01

    ;'Neue Perspektiven fuer dezentrale Kraft-Waerme-Kopplung''. Vom Forum C, ''Neue Perspektiven fuer erneuerbare Energien'', wurde ein Vortrag fuer die Datenbank bearbeitet. (orig./CB)

  5. EVALUATION OF LINERBOARD PROPERTIES FROM MALAYSIAN CULTIVATED KENAF SODA-ANTHRAQUINONE PULPS VERSUS COMMERCIAL PULPS

    Directory of Open Access Journals (Sweden)

    Ahmad Azizi Mossello

    2010-06-01

    Full Text Available Malaysian cultivated kenaf has been identified as a suitable raw material for linerboard production. This study examines the soda-antraquinone (soda-AQ pulp of kenaf fibers versus old corrugated container (OCC and unbleached softwood kraft pulps as the main sources for linerboard production. The results showed significant differences among the pulp properties. The unbleached kraft pulp with very high freeness required high beating to reach an optimized freeness and produced paper with the highest strength properties, except for tear resistance. The OCC gave paper with the lowest strength properties. In the case of kenaf fractions, bast pulp with high freeness needed less beating than softwood and produced paper with high tear resistance. Core fiber, which had the lowest freeness and highest drainage time, led to paper with high strength but very low tear resistance. Kenaf whole stem pulp showed intermediate properties between core and bast and close to those of unbleached softwood pulp, but with very lower beating requirement. Finally, kenaf whole stem, due to its strength properties, moderate separation cost, and simple pulping process, was judged to be more suitable for commercialization for linerboard production in Malaysia.

  6. A xylanase-aided enzymatic pretreatment facilitates cellulose nanofibrillation.

    Science.gov (United States)

    Long, Lingfeng; Tian, Dong; Hu, Jinguang; Wang, Fei; Saddler, Jack

    2017-11-01

    Although biological pretreatment of cellulosic fiber based on endoglucanases has shown some promise to facilitate cellulose nanofibrillation, its efficacy is still limited. In this study, a xylanase-aided endoglucanase pretreatment was assessed on the bleached hardwood and softwood Kraft pulps to facilitate the downstream cellulose nanofibrillation. Four commercial xylanase preparations were compared and the changes of major fiber physicochemical characteristics such as cellulose/hemicellulose content, gross fiber properties, fiber morphologies, cellulose accessibility/degree of polymerization (DP)/crystallinity were systematically evaluated before and after enzymatic pretreatment. It showed that the synergistic cooperation between endoglucanase and certain xylanase (Biobrite) could efficiently "open up" the hardwood Kraft pulp with limited carbohydrates degradation (cellulose nanofibrillation during mild sonication process (90Wh) with more uniform disintegrated nanofibril products (50-150nm, as assessed by scanning electron microscopy and UV-vis spectroscopy). Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. A novel and efficient oxidative functionalization of lignin by layer-by-layer immobilised Horseradish peroxidase.

    Science.gov (United States)

    Perazzini, Raffaella; Saladino, Raffaele; Guazzaroni, Melissa; Crestini, Claudia

    2011-01-01

    Horseradish peroxidase (HRP) was chemically immobilised onto alumina particles and coated by polyelectrolytes layers, using the layer-by-layer technique. The reactivity of the immobilised enzyme was studied in the oxidative functionalisation of softwood milled wood and residual kraft lignins and found higher than the free enzyme. In order to investigate the chemical modifications in the lignin structure, quantitative (31)P NMR was used. The immobilised HRP showed a higher reactivity with respect to the native enzyme yielding extensive depolymerisation of lignin. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Comparison of critical circumferential through-wall-crack-lengths in welds between pieces of straight pipes to welds between straigth pipes and bends with and without internal pressure at force- and displacement-controlled bending load; Vergleich kritischer Umfangsdurchrisslaengen in Schweissnaehten zwischen Geradrohrstuecken mit Schweissnaehten an Rohrbogen-Geradrohrverbindungen mit und ohne Innendruck bei kraft- und wegkontrollierter Biegebelastung

    Energy Technology Data Exchange (ETDEWEB)

    Steinbuch, R [Fachhochschule fuer Technik und Wirtschaft Reutlingen (Germany). Fachbereich Maschinenbau

    1998-11-01

    zahlreichen Forschungsprojekten entwickelt und verifiziert. In den letzten Jahren hat sich insbesondere die Unterscheidung der Beanspruchung in kraft- und wegkontrollierte Lasten als wesentliches Merkmal herausgestellt und entsprechende Beachtung in den neueren Berechnungsverfahren gefunden. Die bisher entwickelten Verfahren gehen von Schaedigungen in Schweissnaehten zwischen Geradrohrstuecken aus. Damit wird die tatsaechliche Position der Naehte in Rohrleitungssystemen nur unvollstaendig beschrieben, da beim heutigen Stand der Technik Umfangsnaehte in Rohrleitungen nur selten zwischen Geraderohrstuecken auftreten. Die meisten Naehte verbinden Rohrstuecke mit Boegen bzw. Boegen mit verlaengerten Enden, Stutzen oder T-Stuecken. Eine nichtlineare Finite-Elemente-Parameterstudie von Innendruck- und ebener Biegebelastung, die einen grossen Teil der relevanten Rohrleitungen des Primaer- und Sekundaerleitungssystems abdeckt, vergleicht die Beanspruchung von Umfangsdurchrissen in Bogenanschlussnaehten mit denen zwischen Geradrohrstuecken. Bei der fuer die Umfangsnaehte relevanten wegkontrollierten Biegebeanspruchung infolge behinderter Waermedehnung des Systems treten an den Bogen-Rohr-Naehten bei den heute ueblichen Innendruckniveaus kleinere bzw. vergleichbare Beanspruchungen und damit groessere oder nahezu gleich grosse kritische Durchrisslaengen wie in Rohr-Rohr-Verbindungen auf. Bei kraftkontrollierten Lasten sehen die Regelwerke staerkere Einschraenkungen der Beanspruchungen vor. Im Bereich zulaessiger Lasten sind die kritischen Durchrisslaengen in Bogenanschlussnaehten aehnlich gross wie die in Verbindungen von Geradrohren. Es ist in den interessierenden Faellen konservativ bis realistisch die fuer Geradrohrstuecke gefundenen kritischen Durchrisslaengen zu uebernehmen. (orig.)

  9. Earnings management environment : with the case of Troms Kraft

    OpenAIRE

    Nødset, Ingrid Foss

    2012-01-01

    In this paper I examine the topic of earnings management and use a case example. In the first part of the paper I review theory on two closely related topics - earnings management and fraud - and present and discuss incentives, methods, typical indications and frequency of earnings management in the financial statements. I continue to describe the frameworks and laws that apply to revenue recognition and how income is recognized in the power industry, as this is especially relevant for the ca...

  10. ASSESSMENT OF IN VITRO ANDROGENIC ACTIVITY IN KRAFT MILL EFFLUENT

    Science.gov (United States)

    Detection of In Vitro Androgenic Activity in Feedlot Effluent. Lambright, CS 1 , Guillette, LJ, Jr.2, Gray, LE, Jr.1 , 1USEPA, NHEERL, RTP, NC, 2 University of Florida, Dept. of Zoology, Gainesville FLRecent studies have shown the presence of androgenic activity in water...

  11. Grouping eucalyptus species in kraft pulp process for cost reduction

    Directory of Open Access Journals (Sweden)

    Apiwan Pichayadecha

    2014-12-01

    Full Text Available The objective of this research is to study the level of the important factors that can decrease total cost of pulp production. First of all, experts and experienced users identify the factors that affect the total production cost by applying the principle of 4M 1E cause and effect diagram. Then the primary factors were chosen based on 80% of their significance and tested by hypothesis for two population means. It was found that at the 95% confidence level the significant factors that have effects on the total production cost are amount of Effective alkali in white liquor and Kappa number. However, the proportion of easy delignification according to Eucalyptus species is considered as a significant factor based on various studies. Box-Behnken experiment is designed with respect to 3 mentioned factors and 3 levels of each factor. The response surface method (RSM is employed to determine the non-linear relation between the total cost as the response and the proportion of easy delignification, amount of Effective alkali in white liquor and Kappa number. To minimize the total cost, the optimal values of each factor are 75% of easy delignification, 112 grams per liter of Effective alkali in white liquor and 13.5 of kappa number. Under this optimal condition, the average total cost per ton of Eucalyptus is 13,393.91 Baht which is significantly less than the total cost of 15,517.06 Baht per ton before improvement.

  12. Kraft-Wärmekopplung und Blockheiz-Kraftwerke BHKW

    Science.gov (United States)

    Zahoransky, Richard; Allelein, Hans-Josef; Bollin, Elmar; Oehler, Helmut; Schelling, Udo

    Die thermischen Wirkungsgrade von Kraftwerken zur Stromerzeugung sind relativ gering. Beispielsweise erreichen moderne Kohlekraftwerke heute bis etwa 45 %, Gasturbinen maximal 40 % und Diesel-Motoren nicht über 50 %. Kombinations-Kraftwerke, Gas- und Dampfturbinen-Prozesse können an die 60 % thermischer Wirkungsgrad bei der Umwandlung der zugeführten Wärme in mechanische bzw. elektrische Energie erzielen. Ein ähnlich hoher Wert wird in Zukunft von den Brennstoffzellen erwartet. Der nicht in Arbeit umgewandelte Anteil der zugeführten Wärme fällt als Abwärme an und geht ungenutzt in die Umgebung. Ein Teil dieser Abwärme lässt sich durch entsprechende Installationen bei allen Kraftwerksprozessen zur Wassererwärmung oder zur Dampferzeugung für industrielle Zwecke nutzen. Für Heizzwecke genügt eine Temperatur der Abwärme von 60 %C bis 80 %C, während die Erzeugung von Industriedampf deutlich höhere Temperaturen voraussetzt.

  13. Sulfate reduction and carbon removal during kraft char burning

    Energy Technology Data Exchange (ETDEWEB)

    Waag, K.J.; Frederick, W.J.; Sricharoenchaikul, V [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemical Engineering; Grace, T.M. [T.M. Grace Company, Appleton, WI (United States); Kymalainen, M. [Tampella Power, Tampere (Finland)

    1995-12-31

    An improved mathematical model of char burning during black liquor combustion was described. Enhancements include a proper treatment of CO{sub 2} and H{sub 2}O gasification, reactions between oxygen and combustibles in the boundary layer, and integration of sulfate reduction and sulfide reoxidation into the char burning process. Gasification of char carbon by reaction with H{sub 2}O and CO{sub 2} proved to be the most important means of carbon release under typical recovery furnace conditions. Sulfate reduction was shown to be responsible for only a minor part of the carbon release. Simulations showed that for typical recovery boiler conditions, char burning behavior is independent of oxygen concentration up to the point of carbon depletion. After carbon depletion, sulfide reoxidation occurs at a rate determined by oxygen mass transfer. Process variables that had the biggest effect on char burning behavior were initial black liquor drop diameter and temperature; also there was a direct link between char burnout times and the amount of sulfate reduction. At a given temperature, any variable that shortened the char burnout time resulted in proportionately less reduction. 22 refs., 10 figs., 2 tabs.

  14. Ich glaube nicht an übersinnliche Kraft hinter Naturgesetzen

    CERN Document Server

    2005-01-01

    The European Organisation for Nuclear Research CERN in Geneva is the leader in research sector of the elementary particles. And a sud-tyrolean has an essential interest in it. Südtirol Online speaks with this physicist about Universe, the smallest components in nature, and about the question: "What is behind?"

  15. Keskpanga ja rahaliitude roll stabiilses majanduses / Vahur Kraft

    Index Scriptorium Estoniae

    Kraft, Vahur, 1961-

    2004-01-01

    Keskpankade rollist ajaloos ja tänapäeval, Ladina ja Skandinaavia rahaliitudest, Euroopa Majandus- ja Rahaliidust, rahapoliitika koordineerimise vajaduses, Eesti Pangast valuutakomitee funktsioonidest, euroala rahapoliitikast, Euroopa Keskpankade Süsteemist ning Eesti Panga rollist tulevikus. Tabel: Maastrichti kriteeriumid

  16. The structure and behavior of salts in kraft recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Backman, R.; Badoi, R.D.; Enestam, S. [Aabo Akademi Univ., Turku (Finland). Combustion Chemistry Research Group

    1997-10-01

    The melting behavior in the salt system (Na,K)(CO{sub 3},SO{sub 4},S,Cl,OH) is investigated by laboratory methods to enhance and further develop a chemical model for salt mixtures with compositions relevant for recovery boilers. The model, based on both literature data and experimental work can be used as (a) submodel in models for the over-all chemistry in recovery boilers and to estimate (b) deposit formation on heat transfer surfaces (fouling), (c) the melting properties of the fly ash, and (d) the smelt bed in recovery boilers. Experimental techniques used are thermal analysis, high temperature microscopy` and scanning electron microscopy. The model is implemented in a global calculation model which can handle both gas phases and condensed phases in the recovery boiler. The model gives a detailed description of the chemical reactions involved in the fume and dust formation in different locations of the flue gas channel in the boiler. (orig.)

  17. MOLYBDENUM CATALYZED ACID PEROXIDE BLEACHING OF EUCALYPTUS KRAFT PULP

    Directory of Open Access Journals (Sweden)

    Marcos S. Rabelo

    2008-08-01

    Full Text Available Molybdenum catalyzed peroxide bleaching (PMo Stage consists of pulp treatment with hydrogen peroxide under acidic conditions in the presence of a molybdenum catalyst. Molybdenum is applied in catalytic doses (50-200 mg/kg pulp and may originate from various sources, including (NH46Mo7O24.4H2O, Na2MoO4.2H2O, siliconmolybdate, etc. This work is aimed at optimizing the PMo stage and evaluating its industrial application in the OAZDP sequence. Optimum PMo stage conditions for bleaching eucalyptus pulp were 90 ºC, pH 3.5, 2 h, 0.1 kg/adt Mo and 5 kg/adt H2O2. The PMo stage was more efficient to remove pulp hexenuronic acids than lignin. Its efficiency decreased with increasing pH in the range of 1.5-5.5, while it increased with increasing temperature and peroxide and molybdenum doses. The application of the PMo stage as replacement for the A-stage of the AZDP sequence significantly decreased chlorine dioxide demand. The PMo stage caused a decrease of 20-30% in the generation of organically bound chlorine. The quality parameters of the pulp produced during the PMo stage mill trial were comparable to those obtained with the reference A-stage.

  18. Revising the NOx BACT Limit at Simpson Tacoma Kraft

    Science.gov (United States)

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  19. Bambu como matéria-prima para papel: IV - Estudos sôbre o emprêgo de cinco espécies de Bambusa,na produção de celulose sulfato Bamboo as a raw material for the pulp and paper industry: IV - Study of Bambusa tuldoides, B. textilis, B. ventricosa, B. malingensis and B. dissimulator in the production of kraft pulp

    Directory of Open Access Journals (Sweden)

    Anísio Azzini

    1971-05-01

    Full Text Available Com o presente trabalho, os autores dão continuidade aos estudos com que se procura determinar as características papeleiras das principais espécies de bambu com bom desenvolvimento nas condições ecológicas do Estado de São Paulo. Bambusa tuldoides, B. textilis, B. ventricosa, B. malingensis e B. dissimulator foram estudadas levando-se em consideração as seguintes variáveis: dimensões dos colmos, densidade básica, análise micrométrica das fibras, rendimento em celulose sulfato (Kraft e características físico-mecânicas das pastas produzidas. As densidades básicas médias calculadas para as espécies em estudo não apresentaram muita variação, com valores extremos de 0,62 e 0,78. Relativamente ao comprimento médio das fibras, as espécies de bambu estudadas mostraram ocupar uma posição intermediária entre as resinosas e as principais espécies arbóreas folhosas utilizadas pela indústria de papel. Os rendimentos médios em celulose sulfato, considerando cinco repetições, foram de 43,75% para B. textilis, 42,53% para B. tuldoides, 41,74% para B. ventricosa, 36,57% para B. dissimulator e 35,82% para B. malingensis, com número de permanganato variando de 18,37 a 17,03. Análise estatística dos dados de resistência do papel demonstrou que B. dissimulator, com exceção do índice de rasgo, apresentou maiores valores que as demais espécies em estudo.Five bamboo species, very similar in the agronomic features, were studied in the production of kraft pulp. All of them have culms with about 9 m in height, 4-5 cm in diameter and weight of 4-5 kg, growing very well in the soil and climate conditions of São Paulo State. Determinations of the basic density of culms and dimension of fibres were made. Chips were obtained mechanically and the cookings were made by the sulfate process at 160°C for l hour, using 14% Na(20 and 25% sul-phidity. Bambusa textilis and B. tuldoides which yielded, respectively 43.75% and 42.53% of

  20. Optical transparency of paper as a function of moisture content with applications to moisture measurement.

    Science.gov (United States)

    Forughi, A F; Green, S I; Stoeber, B

    2016-02-01

    Accurate measurement of the moisture content of paper is essential in papermaking and is also important in some paper-based microfluidic devices. Traditional measurement techniques provide very limited spatiotemporal resolution and working range. This article presents a novel method for moisture content measurement whose operating principle is the strong correlation between the optical transparency of paper and its moisture content. Spectrographic and microscopic measurement techniques were employed to characterize the relation of moisture content and relative transparency of four types of paper: hardwood chemi-thermomechanical pulp paper, Northern bleached softwood kraft paper, unbleached softwood kraft paper, and General Electric(®) Whatman™ grade 1 chromatography paper. It was found that for all paper types, the paper transparency increased monotonically with the moisture content (as the ratio of the mass-of-water to the mass-of-dry-paper increased from 0% to 120%). This significant increase in relative transparency occurred due to the refractive index matching role of water in wet paper. It is further shown that mechanical loading of the paper has little impact on the relative transparency, for loadings that would be typical on a paper machine. The results of two transient water absorption experiments are presented that show the utility and accuracy of the technique.

  1. Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials.

    Science.gov (United States)

    Nilsson, Ting Yang; Wagner, Michal; Inganäs, Olle

    2015-12-07

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by (31) P nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70 mA h g(-1) ). The modification of softwood and hardwood lignin derivatives yielded 50 % and 23 % higher charge capacity than the original lignin, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Amenability of Acacia and Eucalyptus Hardwood Pulps to Elemental Chlorine-Free Bleaching: Application and Efficacy of Microbial Xylanase

    Directory of Open Access Journals (Sweden)

    Avdhesh Kumar Gangwar

    2015-10-01

    Full Text Available This study outlines the results of a biobleaching study of acacia (A. mangium and eucalyptus (E. globulus hardwood kraft pulps with commercial xylanase (Optimase CX 72 L. The comparative study was carried out using an elemental chlorine-free (ECF bleaching sequence (D0EPD1D2 after the enzyme (X stage. The enzyme treatment resulted in improved optical properties with a reduction in bleach chemical consumption. At an equivalent bleach chemical consumption, a brightness gain of 2.1 and 1.7 units and a whiteness gain of 2.7 and 2.3 units were observed with xylanase treatment in acacia and eucalyptus pulps, respectively. In ECF bleaching using the D0EPD1D2 sequence, a final brightness was achieved to the extent of 90% ISO and 89% ISO for acacia and eucalyptus, respectively, at an equivalent charge of bleach chemicals. The post-color (PC number was also reduced by up to 45% for both hardwood pulps compared with the control. The bleachability of acacia was observed to be significantly higher than that of eucalyptus. In addition, a 17.0% and 23.0% reduction in chlorine dioxide and sodium hydroxide, respectively, were obtained for both hardwood pulps after xylanase pre-bleaching, thus indicating an environmentally friendly approach to the process.

  3. STUDIES ON XYLANASE AND LACCASE ENZYMATIC PREBLEACHING TO REDUCE CHLORINE-BASED CHEMICALS DURING CEH AND ECF BLEACHING

    Directory of Open Access Journals (Sweden)

    Vasanta V. Thakur,

    2012-02-01

    Full Text Available The biobleaching efficiency of xylanase and laccase enzymes was studied on kraft pulps from wood and nonwood based raw materials employed in the Indian paper industry. Treatment of these pulps with xylanase enzyme could result in improved properties, showing 2.0% ISO gain in pulp brightness and/or reducing the demand of chlorine-based bleach chemicals by up to 15% with simultaneous reduction of 20 to 25% in AOX generation in bleach effluents. Further, mill-scale trial results revealed that enzymatic prebleaching can be successfully employed with xylanases to reach the same bleach boosting efficacy. Laccase bleaching was also studied on hardwood pulp at a pH around 8.0, where most of the pulp mills in India are operating, in contrast to earlier studies on laccase enzyme bleaching, which were conducted at acidic pHs, i.e. 4.0 to 5.0. In case of laccase bleaching, interesting results were found wherein a bleach-boosting effect was observed even at pH 8.0. Further studies carried out with HOBT as mediator in comparison to the commonly used and expensive ABTS laccase mediator system (LMS resulted in improvement of the bleaching efficiency with reduction in demand of chlorine dioxide by more than 35%. Potential for further reduction was indicated by the brightness gain, when compared with a control using the DE(pD bleach sequence.

  4. Assessing mechanical deconstruction of softwood cell wall for cellulosic biofuels production

    Science.gov (United States)

    Jiang, Jinxue

    Mechanical deconstruction offers a promising strategy to overcome biomass recalcitrance for facilitating enzymatic hydrolysis of pretreated substrates with zero chemicals input and presence of inhibitors. The goal of this dissertation research is to gain a more fundamental understanding on the impact of mechanical pretreatment on generating digestible micronized-wood and how the physicochemical characteristics influence the subsequent enzymatic hydrolysis of micronized wood. The initial moisture content of feedstock was found to be the key factor affecting the development of physical features and enzymatic hydrolysis of micronized wood. Lower moisture content resulted in much rounder particles with lower crystallinity, while higher moisture content resulted in the milled particles with larger aspect ratio and crystallinity. The enzymatic hydrolysis of micronized wood was improved as collectively increasing surface area (i.e., reducing particle size and aspect ratio) and decreasing crystallinity during mechanical milling pretreatment. Energy efficiency analysis demonstrated that low-moisture content feedstock with multi-step milling process would contribute to cost-effectiveness of mechanical pretreatment for achieving more than 70% of total sugars conversion. In the early stage of mechanical pretreatment, the types of cell fractures were distinguished by the initial moisture contents of wood, leading to interwall fracture at the middle lamella region for low moisture content samples and intrawall fracture at the inner cell wall for high moisture content samples. The changes in cell wall fractures also resulted in difference in the distribution of surface chemical composition and energy required for milling process. In an effort to exploit the underlying mechanism associated with the reduced recalcitrance in micronized wood, we reported the increased enzymatic sugar yield and correspondingly structural and accessible properties of micronized feedstock. Electronic microscopy analysis detailed the structural alternation of cell wall during mechanical process, including cell fracture and delamination, ultrastructure disintegration, and cell wall fragments amorphization, as coincident with the particle size reduction. It was confirmed with Simons' staining that longer milling time resulted in increased substrate accessibility and porosity. The changes in cellulose molecular structure with respect to degree of polymerization (DP) and crystallinity index (CrI) also benefited to decreasing recalcitrance and facilitating enzymatic hydrolysis of micronized wood.

  5. Two-dimensional finite element heat transfer model of softwood. Part I, Effective thermal conductivity

    Science.gov (United States)

    John F. Hunt; Hongmei Gu

    2006-01-01

    The anisotropy of wood complicates solution of heat and mass transfer problems that require analyses be based on fundamental material properties of the wood structure. Most heat transfer models use average thermal properties across either the radial or tangential direction and do not differentiate the effects of cellular alignment, earlywood/latewood differences, or...

  6. 78 FR 77329 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Changes...

    Science.gov (United States)

    2013-12-23

    ...); adds flexibility for the Board to nominate eligible persons to fill vacancies that occur during a term... operate (U.S. or import); add flexibility for the Board to nominate eligible persons to fill vacancies... and Border Protection. 2010 and 2011 U.S. data is from Forest Economic Advisors. It is noted that for...

  7. 76 FR 46185 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order

    Science.gov (United States)

    2011-08-02

    ... data was compiled by Henry Spelter of Wood Futures Insight and Forest Economic Advisors. For 2008-2009... the Board indicating their desire to serve or nominating another industry member to serve on the Board... serve or to nominate another industry member to serve on the Board. Interested persons may also submit a...

  8. 78 FR 58956 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Changes...

    Science.gov (United States)

    2013-09-25

    ... in any region in which they operate (U.S. or import); add flexibility for the Board to nominate... they operate (U.S. or import); add flexibility for the Board to nominate eligible persons to fill... and Border Protection. 2010 and 2011 U.S. data is from Forest Economic Advisors. It is noted that for...

  9. Competitiveness of U.S. wood furniture manufacturers - Lessons learned from the softwood moulding industry

    Science.gov (United States)

    Al Schuler; Russ Taylor; Philip A. Araman

    2001-01-01

    The furniture industry in the United States has been losing market share to imports for the past two decades. This article focuses on the market segment where most of the loss has occurred: the important wood household (non-upholstered) sector (SIC code 2511). In the upholstered furniture sector, exports are still larger than imports. But the wood household furniture...

  10. Microscopic and Spectroscopic Characterisation of Waterlogged Archaeological Softwood from Anoxic Environments

    DEFF Research Database (Denmark)

    Pedersen, Nanna Bjerregaard

    waterlogged sites and solely decayed by erosion bacteria to refine the understanding of the residual wood structure left after degradation. This was done not only to improve the ability to develop suitable and cost effective conservations treatments but also to improve the understanding of anaerobic decay...... mechanisms acting on plant biomass in waterlogged anoxic environment.Morphological analyses showed typical erosion bacteria decay patterns in the residual wood structure. Decay resistance of some cell types and cell wall compartments in preference to others is most likely explained not only by elevated...

  11. PLYMAP : a computer simulation model of the rotary peeled softwood plywood manufacturing process

    Science.gov (United States)

    Henry Spelter

    1990-01-01

    This report documents a simulation model of the plywood manufacturing process. Its purpose is to enable a user to make quick estimates of the economic impact of a particular process change within a mill. The program was designed to simulate the processing of plywood within a relatively simplified mill design. Within that limitation, however, it allows a wide range of...

  12. Stabilization of Softwood-Derived Pyrolysis Oils for Continuous Bio-oil Hydroprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Olarte, Mariefel V.; Zacher, Alan H.; Padmaperuma, Asanga B.; Burton, Sarah D.; Job, Heather M.; Lemmon, Teresa L.; Swita, Marie S.; Rotness, Leslie J.; Neuenschwander, Gary N.; Frye, John G.; Elliott, Douglas C.

    2015-10-15

    The use of fast pyrolysis as a potential renewable liquid transportation fuel alternative to crude oil depends on successful catalytic upgrading to produce a refinery-ready product with oxygen content and qualities (i.e. specific functional group or compound content) that is compatible with the product’s proposed insertion point. Catalytic upgrading of bio-oil requires high temperature and pressure, while similar to crude oil hydrotreating, is not as straightforward for the thermally unstable pyrolysis oil. For years, a two-temperature zone, downflow trickle bed reactor was the state-of-the art for continuous operation. However, pressure excursion due to plug formation still occurred, typically at the high temperature transition zone, leading to a process shutdown within 140 h. Recently, a bio-oil pre-treatment process, together with a robust commercial catalyst, was found to be enabling the continuous operation of the two-zone hydroprocessing system. Here, we report the results on pre-treating bio-oil at 413 K and 8.4 MPa of flowing H2 (500 L H2/L bio-oil, 0.5 L bio-oil/L catalyst bed) and the attempts to characterize this oil product to understand the chemistry which enabled the long-term processing of bio-oil.

  13. Spectroscopic analysis of hot-water- and dilute-acid-extracted hardwood and softwood chips

    Science.gov (United States)

    Lehto, Joni; Louhelainen, Jarmo; Huttunen, Marko; Alén, Raimo

    2017-09-01

    Hot-water and dilute sulfuric acid pretreatments were performed prior to chemical pulping for silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips to determine if varying pretreatment conditions on the original wood material were detectable via attenuated total reflectance (ATR) infrared spectroscopy. Pretreatment conditions varied with respect to temperature (130 °C and 150 °C) and treatment time (from 30 min to 120 min). The effects of the pretreatments on the composition of wood chips were determined by ATR infrared spectroscopy. The spectral data were compared to those determined by common wood chemistry analyses to evaluate the suitability of ATR spectroscopy method for rapid detection of changes in the wood chemical composition caused by different pretreatment conditions. In addition to determining wood species-dependent differences in the wood chemical composition, analytical results indicated that most essential lignin- and carbohydrates-related phenomena taking place during hot-water and acidic pretreatments could be described by applying this simple spectral method requiring only a small sample amount and sample preparation. Such information included, for example, the cleavage of essential lignin bonds (i.e., mainly β-O-4 linkages in guaiacyl and syringyl lignin) and formation of newly condensed lignin structures under different pretreatment conditions. Carbohydrate analyses indicated significant removal of hemicelluloses (especially hardwood xylan) and hemicelluloses-derived acetyl groups during the pretreatments, but they also confirmed the highly resistant nature of cellulose towards mild pretreatments.

  14. Acid bi-sulphite pulping effects on hardwoods and a softwood revealed by atomic force microscopy

    CSIR Research Space (South Africa)

    Chunilall, Viren

    2009-12-01

    Full Text Available Wood fibres are the raw material used in the production of dissolving pulp for the manufacture of cellulose derivatives such as viscose and cellulose acetate. At the microscopic level, the wood cell wall is organised in layers with different...

  15. Borate protection of softwood from Coptotermes acinaciformis (Isoptera: Rhinotermitidae) damage: variation in protection thresholds explained.

    Science.gov (United States)

    Peters, Brenton C; Fitzgerald, Christopher J

    2006-10-01

    Laboratory and field data reported in the literature are confusing with regard to "adequate" protection thresholds for borate timber preservatives. The confusion is compounded by differences in termite species, timber species and test methodology. Laboratory data indicate a borate retention of 0.5% mass/mass (m/m) boric acid equivalent (BAE) would cause > 90% termite mortality and restrict mass loss in test specimens to 0.5% m/m BAE are required. We report two field experiments with varying amounts of untreated feeder material in which Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae) responses to borate-treated radiata (Monterey) pine, Pinus radiata D. Don, were measured. The apparently conflicting results between laboratory and field data are explained by the presence or absence of untreated feeder material in the test environment. In the absence of untreated feeder material, wood containing 0.5% BAE provided adequate protection from Coptotermes sp., whereas in the presence of untreated feeder material, increased retentions were required. Furthermore, the retentions required increased with increased amounts of susceptible material present. Some termites, Nasutitermes sp. and Mastotermes darwiniensis Froggatt, for example, are borate-tolerant and borate timber preservatives are not a viable management option with these species. The lack of uniform standards for termite test methodology and assessment criteria for efficacy across the world is recognized as a difficulty with research into the performance of timber preservatives with termites. The many variables in laboratory and field assays make "prescriptive" standards difficult to recommend. The use of "performance" standards to define efficacy criteria ("adequate" protection) is discussed.

  16. 75 FR 61001 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order

    Science.gov (United States)

    2010-10-01

    ... lumber is used in products like flooring, siding and framing. The program would be financed by an... whether they favor implementation of the program prior to it going into effect. This rule also announces... Executive Order 12988, Civil Justice Reform. It is not intended to have retroactive effect. Section 524 of...

  17. Exploratory radio-frequency/vacuum drying of three B.C. coastal softwoods

    International Nuclear Information System (INIS)

    Avramidis, S.; Zwick, R.L.

    1992-01-01

    Five exploratory drying runs were carried out in a commercial size (23 m3) radio-frequency/vacuum (RF/V) kiln. The species investigated were Pacific Coast hemlock, Douglas-fir, and western redcedar of different sizes and grades. Evaluation of the dried lumber showed that the three species can be dried in very short times with a low amount of degrade with the exception of clear cedar, which exhibited severe internal honeycombing; indicating the need to develop proper kiln schedules for this drying process. The thermodynamic and sensitivity analyses performed showed that above certain efficiency levels, RF/V drying is economical and fast. This finding was particularly true with lumber thicknesses over 8 cm

  18. Amphipathic lignin derivatives to accelerate simultaneous saccharification and fermentation of unbleached softwood pulp for bioethanol production.

    Science.gov (United States)

    Cheng, Ningning; Yamamoto, Yoko; Koda, Keiichi; Tamai, Yutaka; Uraki, Yasumitsu

    2014-12-01

    Amphipathic lignin derivatives (A-LDs) were already demonstrated to improve enzymatic saccharification of lignocellulose. Based on this knowledge, two kinds of A-LDs prepared from black liquor of soda pulping of Japanese cedar were applied to a fed-batch simultaneous saccharification and fermentation (SSF) process for unbleached soda pulp of Japanese cedar to produce bioethanol. Both lignin derivatives slightly accelerated yeast fermentation of glucose but not inhibited it. In addition, ethanol yields based on the theoretical maximum ethanol production in the fed-batch SSF process was increased from 49% without A-LDs to 64% in the presence of A-LDs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Numerical modelling of the time-dependent mechanical behaviour of softwood

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2010-01-01

    When using wood as a structural material it is important to consider its time-dependent mechanical behaviour and to predict this behaviour for decades ahead. For this purpose, several rheological mathematical models, spanning from fairly simple to very complex ones, have been developed over...

  20. Moisture-related mechanical properties of softwood: 3D micromechanical modeling

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2009-01-01

    Computational micromechanical analysis of the influence of moisture, density and microstructure of latewood on its hydroelastic and shrinkage properties is carried out. The elastic properties of cell sublayers have been determined using the unit cell models as for fiber reinforced composites (two....... The results for elastic properties of cell sublayers obtained from the unit cell models, from the self-consistent method and Halpin-Tsai equations are compared, and good agreement between these methods was observed. A computational technique, based on the representation of moisture effect as equivalent...... temperature-caused effects, has been developed and employed to the modeling of the moisture-related changes of the elastic properties of cell layers. A series of computational experiments have been carried out. In the simulations, it was observed that the shrinkage coefficients of longitudinal direction...

  1. 78 FR 24152 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Request...

    Science.gov (United States)

    2013-04-24

    ... at www.regulations.gov or sent to the Promotion and Economics Division, Fruit and Vegetable Program... assessments. The information collection requirements in the request are essential to carry out the intent of...

  2. Projecting housing starts and softwood lumber consumption in the United States

    Science.gov (United States)

    Jeffrey P. Prestemon; David N. Wear; Karen L. Abt; Robert C. Abt

    2018-01-01

    New residential construction is a primary user of wood products in the United States; therefore, wood products projections require understanding the determinants of housing starts. We model quarterly US total, single-family, and multifamily housing starts with several model specifications, using data from 1979 to 2008, and evaluate their...

  3. Interactions between domestic and export markets for softwood lumber and plywood: tests of six hypotheses.

    Science.gov (United States)

    David R. Darr

    1981-01-01

    Price formation in export markets and available data on export and domestic markets are discussed. The results of tests of several hypotheses about interactions between domestic and export markets are presented and interpreted from the standpoints of trade promotion and trade policy.

  4. Effect of hot water extracted hardwood and softwood chips on particleboard properties

    Science.gov (United States)

    Manuel Raul Pelaez-Samaniego; Vikram Yadama; Tsai Garcia-Perez; Eini Lowell; Thomas Amidon

    2014-01-01

    The affinity of particleboard (PB) to water is one of the main limitations for using PB in moisture-rich environments. PB dimensional stability and durability can be improved by reducing the available hydroxyl groups in wood through hemicellulose removal, for example, by hot water extraction (HWE), which increases wood resistance to moisture uptake. The resulting...

  5. Multistep process to produce fermentable sugars and lignosulfonates from softwood enzymolysis residues

    Science.gov (United States)

    Yalan Liu; Jinwu Wang; Michael P. Wolcott

    2016-01-01

    The residual solids from enzymatic hydrolysis are usually burned to produce energy and have been explored as a feedstock for various products including activated carbon and lignin based polymers. These products require additional procedures unrelated to the existing biorefinery equipment. In the current study, we proposed successive sulfite treatments to utilize the...

  6. Biorefinery lignosulfonates from sulfite-pretreated softwoods as dispersant for graphite

    Science.gov (United States)

    Yanlin Qin; Lixuan Yu; Ruchun Wu; Dongjie Yang; Xueqing Qiu; Junyong Zhu

    2016-01-01

    Two biorefinery lignosulfonates (LSs), Ca-LS-DF and Na-LS-LP were, respectively, isolated from pilot-scale sulfite-pretreated spent liquor of lodgepole pine and fermentation residue of Douglas-fir harvest forest residue. The molecular weights of Na-LS-LP and Ca-LS-DF were approximately 9 000 and 11 000 Da, respectively. The two LSs were applied as dispersant for...

  7. Tensile strength characteristics of polypropylene composites reinforced with stone groundwood fibers from softwood

    OpenAIRE

    López, Joan Pere; Méndez González, José Alberto; Espinach Orús, Xavier; Julián Pérez, Fernando; Mutjé Pujol, Pere; Vilaseca Morera, Fabiola

    2012-01-01

    The behavior of stone groundwood / polypropylene injection-molded composites was evaluated with and without coupling agent. Stone groundwood (SGW) is a fibrous material commonly prepared in a high yield process and mainly used for papermaking applications. In this work, the use of SGW fibers was explored as a reinforcing element of polypropylene (PP) composites. The surface charge density of the composite components was evaluated, as well as the fiber’s length and diameter inside the composit...

  8. Assessment of wood-inhabiting Basidiomycetes for biokraft pulping of softwood chips

    CSIR Research Space (South Africa)

    Wolfaardt, F

    2004-10-01

    Full Text Available Wood-inhabiting Basidiomycetes have been screened for various applications in the pulp and paper industry and it is evident that different fungi need to be used to suit the specific requirements of each application. This study assessed...

  9. Integrated Forest Products Refinery (IFPR)

    Energy Technology Data Exchange (ETDEWEB)

    van Heiningen, Adriaan R. P.

    2010-05-29

    Pre-extraction–kraft studies of hardwoods showed that when extracting about 10% of the wood, the final kraft pulp yield and physical properties could only be maintained at a level similar to that of regular kraft pulp when the final extract pH was close to neutral. This so-called “near neutral” pre-extraction condition at a level of 10% wood dissolution was achieved by contacting the wood chips with green liquor (GL) at a charge of about 3% (as Na2O on wood) at 160 °C for almost 2 hours (or an H-factor of about 800 hrs.). During subsequent kraft cooking of the pre-extracted hardwood chips the effective alkali charge could be reduced by about 3% (as Na2O on wood) and the cooking time shortened relative to that during regular kraft cooking, while still producing the same bleachable grade kappa number as the kraft control pulp. For softwood, no extraction conditions were discovered in the present investigation whereby both the final kraft pulp yield and physical properties could be maintained at a level similar to that of regular softwood kraft pulp. Therefore for hardwoods the “near- neutral green liquor pre-extraction conditions do meet the requirements of the IFPR concept, while for softwood, no extraction conditions were discovered which do meet these requirements. Application of simulated industrial GL at an extraction H-factor of about 800 hrs and 3% GL charge in a recirculating digester produced an hardwood extract containing about 4% (on wood) of total anhydro-sugars, 2% of acetic acid, and 1.3% of lignin. Xylan comprised of 80% of the sugars of which about 85% is oligomeric. Since only polymeric hemicelluloses and lignin may be adsorbed on pulp (produced at a yield of about 50% from the original wood), the maximum theoretical yield increase due to adsorption may be estimated as 10% on pulp (or 5% on wood). However, direct application of raw GL hardwood extract for hemicelluloses adsorption onto hardwood kraft pulp led to a yield increase of only

  10. Evaluation of kraft paper chemical byproducts in insulating mineral oil of energized transformers; Avaliacao de subprodutos quimicos de papel tipo kraft em oleo mineral isolante de transformadores energizados

    Energy Technology Data Exchange (ETDEWEB)

    Portella, Mariana d' Orey Gaivao; Portella, Kleber Franke; Swinka Filho, Vitoldo; Silva, Guilherme Cunha da; Stocco, Guilherme Barrachina; Batista, Douglas Antonio; Sabec, Daiane Cristina; Deger, Claudio Adriano [Instituto de Tecnologia para o Desenvolvimento (LATEC), Curitiba, PR (Brazil)], E-mails: mariana.portella@lactec.org.br, portella@laclec.org.br; Andreoli, Mario Carlos [Centro de Transmissao de Energia Eletrica Paulista (CTEEP), Sao Paulo, SP (Brazil)], E-mail: mandreoli@cteep.com.br

    2011-10-15

    The insulating paper is a major determinant of the remaining lifetime of an electrical transformer, since it is not possible to analyse or replace this equipment during operation. However, using the quantification of the furanic compounds concentration formed in mineral oil, it is possible to infer about the quality of the material, confirming the presence of degradation. Given the existence of new kinds of solid insulation, this research aimed at studying a new analytical methodology, using the techniques of liquid chromatography with mass detection of these substances in order to increase the reliability of the results, assisting the preventive maintenance. (author)

  11. Extraction of hemicelluloses from wood in a pulp biorefinery, and subsequent fermentation into ethanol

    International Nuclear Information System (INIS)

    Boucher, Jérémy; Chirat, Christine; Lachenal, Dominique

    2014-01-01

    Highlights: • Hemicellulosic ethanol from softwood hemicelluloses in a pulp mill. • Comparison of acid hydrolysis and autohydrolysis to extract hemicelluloses. • Effects of the extraction process conditions on inhibitors concentrations. • Effects of inhibitors on fermentation. - Abstract: This study deals with the production of ethanol and paper pulp in a kraft pulp mill. The use of an acid hydrolysis or a two-step treatment composed of an autohydrolysis followed by a secondary acid hydrolysis was studied. Acid hydrolysis allowed the extraction of higher quantities of sugars but led also to higher degradations of these sugars into inhibitors of fermentation. The direct fermentation of a hydrolysate resulting from an acid hydrolysis gave excellent yields after 24 h. However, the fermentation of hydrolysates after their concentration proved to be impossible. The study of the impact of the inhibitors on the fermentations showed that organic acids, and more specifically formic acid and acetic acid were greatly involved in the inhibition

  12. Treatment of Lignin Precursors to Improve their Suitability for Carbon Fibers: A Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Ryan [GrafTech International Holdings Inc.; Naskar, Amit [Oak Ridge National Laboratory; Gallego, Nidia [Oak Ridge National Laboratory; Dai, Xuliang [GrafTech International Holdings Inc.; Hausner, Andrew [GrafTech International Holdings Inc.

    2015-04-17

    Lignin has been investigated as a carbon fiber precursor since the 1960s. Although there have been a number of reports of successful lignin-based carbon fiber production at the lab scale, lignin-based carbon fibers are not currently commercially available. This review will highlight some of the known challenges, and also the reported methods for purifying and modifying lignin to improve it as a precursor. Lignin can come from different sources (e.g. hardwood, softwood, grasses) and extraction methods (e.g. organosolv, kraft), meaning that lignin can be found with a diversity of purity and structure. The implication of these conditions on lignin as carbon fiber precursor is not comprehensively known, especially as the lignin landscape is evolving. The work presented in this review will help guide the direction of a project between GrafTech and ORNL to develop lignin carbon fiber technology, as part of a cooperative agreement with the DOE Advanced Manufacturing Office.

  13. Effects of Surfactants on the Preparation of Nanocellulose-PLA Composites

    Directory of Open Access Journals (Sweden)

    Kirsi Immonen

    2017-11-01

    Full Text Available Thermoplastic composite materials containing wood fibers are gaining increasing interest in the manufacturing industry. One approach is to use nano- or micro-size cellulosic fibrils as additives and to improve the mechanical properties obtainable with only small fibril loadings by exploiting the high aspect ratio and surface area of nanocellulose. In this study, we used four different wood cellulose-based materials in a thermoplastic polylactide (PLA matrix: cellulose nanofibrils produced from softwood kraft pulp (CNF and dissolving pulp (CNFSD, enzymatically prepared high-consistency nanocellulose (HefCel and microcellulose (MC together with long alkyl chain dispersion-improving agents. We observed increased impact strength with HefCel and MC addition of 5% and increased tensile strength with CNF addition of 3%. The addition of a reactive dispersion agent, epoxy-modified linseed oil, was found to be favorable in combination with HefCel and MC.

  14. Effects of Surfactants on the Preparation of Nanocellulose-PLA Composites.

    Science.gov (United States)

    Immonen, Kirsi; Lahtinen, Panu; Pere, Jaakko

    2017-11-17

    Thermoplastic composite materials containing wood fibers are gaining increasing interest in the manufacturing industry. One approach is to use nano- or micro-size cellulosic fibrils as additives and to improve the mechanical properties obtainable with only small fibril loadings by exploiting the high aspect ratio and surface area of nanocellulose. In this study, we used four different wood cellulose-based materials in a thermoplastic polylactide (PLA) matrix: cellulose nanofibrils produced from softwood kraft pulp (CNF) and dissolving pulp (CNFSD), enzymatically prepared high-consistency nanocellulose (HefCel) and microcellulose (MC) together with long alkyl chain dispersion-improving agents. We observed increased impact strength with HefCel and MC addition of 5% and increased tensile strength with CNF addition of 3%. The addition of a reactive dispersion agent, epoxy-modified linseed oil, was found to be favorable in combination with HefCel and MC.

  15. Oxidative polymerization of lignins by laccase in water-acetone mixture.

    Science.gov (United States)

    Fiţigău, Ionița Firuța; Peter, Francisc; Boeriu, Carmen Gabriela

    2013-01-01

    The enzymatic oxidative polymerization of five technical lignins with different molecular properties, i.e. Soda Grass/Wheat straw Lignin, Organosolv Hardwood Lignin, Soda Wheat straw Lignin, Alkali pretreated Wheat straw Lignin, and Kraft Softwood was studied. All lignins were previously fractionated by acetone/water 50:50 (v/v) and the laccase-catalyzed polymerization of the low molecular weight fractions (Mw Reactivity of lignin substrates in laccase-catalyzed reactions was determined by monitoring the oxygen consumption. The oxidation reactions in 50% acetone in water mixture proceed with high rate for all tested lignins. Polymerization products were analyzed by size exclusion chromatography, FT-IR, and (31)P-NMR and evidence of important lignin modifications after incubation with laccase. Lignin polymers with higher molecular weight (Mw up to 17500 g/mol) were obtained. The obtained polymers have potential for applications in bioplastics, adhesives and as polymeric dispersants.

  16. Potentiometric chemical sensors from lignin-poly(propylene oxide) copolymers doped by carbon nanotubes.

    Science.gov (United States)

    Rudnitskaya, Alisa; Evtuguin, Dmitry V; Costa, Luis C; Graça, M Pedro F; Fernandes, António J S; Correia, M Rosario P; Gomes, M Teresa S R; Oliveira, J A B P

    2013-01-21

    Hardwood and softwood lignins obtained from industrial sulphite and kraft and laboratory oxygen-organosolv pulping processes were employed in co-polymerization with tolylene 2,4-diisocyanate terminated poly(propylene glycol). The obtained lignin-based polyurethanes were doped with 0.72 w/w% of multiwall carbon nanotubes (MWCNTs) with the aim of increasing their electrical conductivity to the levels suitable for sensor applications. Effects of the polymer doping with MWCNTs were assessed using electrical impedance (EIS) and UV-Resonance Raman (UV-RR) spectroscopy. Potentiometric sensors were prepared by drop casting of liquid polymer on the surface of carbon glass or platinum electrodes. Lignin-based sensors displayed a very low or no sensitivity to all alkali, alkali-earth and transition metal cations ions except Cr(VI) at pH 2. Response to Cr(VI) values of 39, 50 and 53 mV pX(-1) for the sensors based on kraft, organosolv and lignosulphonate lignins, respectively, were observed. Redox sensitivity values close to the theoretical values of 20 and 21 mV pX(-1) for organosolv and lignosulphonate based sensors respectively were detected in the Cr(III)/Cr(VI) solutions while a very low response was observed in the solutions containing Fe(CN)(6)(3-/4-). Conducting composite lignin-based polyurethanes doped with MWCNTs were suggested as being promising materials for Cr(VI)-sensitive potentiometric sensors.

  17. Enzymatically and chemically oxidized lignin nanoparticles for biomaterial applications.

    Science.gov (United States)

    Mattinen, Maija-Liisa; Valle-Delgado, Juan José; Leskinen, Timo; Anttila, Tuomas; Riviere, Guillaume; Sipponen, Mika; Paananen, Arja; Lintinen, Kalle; Kostiainen, Mauri; Österberg, Monika

    2018-04-01

    Cross-linked and decolorized lignin nanoparticles (LNPs) were prepared enzymatically and chemically from softwood Kraft lignin. Colloidal lignin particles (CLPs, ca. 200 nm) in a non-malodorous aqueous dispersion could be dried and redispersed in tetrahydrofuran (THF) or in water retaining their stability i.e. spherical shape and size. Two fungal laccases, Trametes hirsuta (ThL) and Melanocarpus albomyces (MaL) were used in the cross-linking reactions. Reactivity of ThL and MaL on Lignoboost™ lignin and LNPs was confirmed by high performance size exclusion chromatography (HPSEC) and oxygen consumption measurements with simultaneous detection of red-brown color due to the formation of quinones. Zeta potential measurements verified oxidation of LNPs via formation of surface-oriented carboxylic acid groups. Dynamic light scattering (DLS) revealed minor changes in the particle size distributions of LNPs after laccase catalyzed radicalization, indicating preferably covalent intraparticular cross-linking over polymerization. Changes in the surface morphology of laccase treated LNPs were imaged by atomic force (AFM) and transmission emission (TEM) microscopy. Furthermore, decolorization of LNPs without degradation was obtained using ultrasonication with H 2 O 2 in alkaline reaction conditions. The research results have high impact for the utilization of Kraft lignin as nanosized colloidal particles in advanced bionanomaterial applications in medicine, foods and cosmetics including different sectors from chemical industry. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Pulp and paper from blue agave waste from tequila production.

    Science.gov (United States)

    Idarraga, G; Ramos, J; Zuñiga, V; Sahin, T; Young, R A

    1999-10-01

    Pulping of blue agave waste, from the production of tequila, was evaluated by both chemical and biomechanical pulping processes. Two conventional and two organosolv systems were used to pulp the agave waste under a standard set of conditions. The soda-ethanol process was superior in terms of delignification and pulp properties in comparison to the soda and ethanol organosolv processes for pulping of agave waste; however, the kraft process gave the best strength properties. In general, the strength of the agave waste pulps was rather poor in comparison to wood and other agro-based pulps; however, the tear strength was relatively high. This result is typical of poorly bonded sheets and may be due to the coarseness of the agave fibers and/or loss of hemicelluloses in the steaming process for the tequila production. Fungal treatment of the agave waste with Ceriporiopsis subvermispora reduced the energy consumption for mechanical refining but gave biomechanical pulps with inferior strength properties. The blue agave chemical pulps should be suitable for blending with softwood kraft pulps for publication grade paper.

  19. The potential for energy savings when reducing the water consumption in a kraft pulp mill

    Energy Technology Data Exchange (ETDEWEB)

    Wising, Ulrika; Berntsson, Thore [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Chemical Engineering and Environmental Science; Stuart, Paul [Ecole Polytechnique, Montreal (Canada). Dept. of Chemical Engineering

    2004-05-01

    In this paper an existing pulp and paper mill has been studied in a systematic way regarding the reduction of water consumption, and the resulting increased potential for energy integration. It has been found that when the mill's hot water consumption is decreased, the live steam demand for the mill also decreases. Also when decreasing the hot water consumption, the quantity and temperature of available excess heat increases. This excess heat can be used for evaporation, thereby reducing the live steam demand further by up to 1.5 GJ/t. A pinch analysis was performed at an existing mill and it was found that if pinch violations are removed, the hot water consumption is not an important factor any more. Removing all the pinch violations and using the remaining excess heat for evaporation yields a significantly larger energy savings for the mill (4.0 GJ/t). From an economic optimum perspective it is probably most profitable to do a combination of reducing water consumption, removing pinch violations, and use the remaining excess heat for evaporation.

  20. Kraft kaebas maksuameti nõude andmeid esitada kohtusse / Peeter Raidla

    Index Scriptorium Estoniae

    Raidla, Peeter, 1955-

    2004-01-01

    Tallinna halduskohtu istungil 10. juunil 2004 vaidlustas Sangar AS-i juhatuse esimeest Gunnar Krafti esindanud advokaat maksu- ja tolliameti nõude, millega endist Eesti Investeerimispanga ja Optiva Panga nõukogu esimeest kohustati esitama andmeid oma vara ja pangakontode kohta seoses uurimise all olnud maksuvaba firma Vermar Finances tehingutega aastail 1997-1999

  1. Production development on the Norwegian continental shelf; KonKraft rapport 2

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    After almost 40 years of virtually uninterrupted growth, total hydrocarbon production on the Norwegian continental shelf (NCS) has reached its highest level ever, with a daily output of 4-4.5 million barrels of oil equivalent per day. It is expected to remain at this level for the next 7 years. After 2015 or thereabouts, however, total oil and gas production is forecast to start declining. Oil production is already falling. Gas output has been increasing, but this is not expected to continue offsetting the drop in liquid production beyond 2015 or thereabouts if no action is taken. Only half the combined oil and gas resources predicted by the Norwegian Petroleum Directorate (NPD) will have been produced in 2015. Remaining recoverable resources, including those expected to be found by further exploration, are currently estimated to be 38-77 billion barrels of oil equivalent (boe). This estimate could be 25-65 billion boe in 2015. Only 40 per cent of the total expected remaining hydrocarbon resources remains to be discovered today, which explains the wide range in the estimates. This huge potential must be managed well to avoid a sharp decline in production and to support a healthy level of long-term investment. The report on production development on the Norwegian continental shelf is published at a time when major changes are taking place both inside and outside the petroleum industry. Several factors make a review of what can be done to address the production decline particularly urgent. Although the current level of activity in the Norwegian petroleum sector is high, assessing the long-term perspectives for the industry is very important. In many cases, the period between the award of licences and the start of production can be 15 years or more. Decisions taken now may have important implications for levels of production and activity in the 2020s. (Author)

  2. Precipitation and valorisation of lignin in South African kraft mill black liquor - first stages: Poster

    CSIR Research Space (South Africa)

    Namane, M

    2013-10-01

    Full Text Available Worldwide, the pulp and paper industry is in decline due to a number of factors such as high production costs, the growing utilization of electronic media that compete with print media and books, as well as pressure for the industry to be more...

  3. Break-through technologies. Power and/or heat generation; Genombrottstekniker. Kraft- vaermeproduktion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This report gives a compilation of technologies for the future in producing electric power and heat. The focus is on the areas Cogeneration, Fuel cells, Wind power, Solar cells, Artificial photosynthesis, and Hydrogen. Refs, 9 figs, 5 tabs

  4. Uso de antraquinona en cocción kraft de Eucalyptus globulus y Eucalyptus nitens

    OpenAIRE

    Moreira, Jorge Felipe Quintana

    2011-01-01

    En la presente disertación se verificó de manera experimental el efecto de la adición de Antraquinona al proceso de cocción batch convencional para una mezcla industrial de Eucalyptus globulus E. nitens.; en lo que respecta a su capacidad de aumentar la velocidad de la reacción de deslignificación y proporcionar estabilidad a las hemicelulosas y celulosas de la fibra. Lo anterior se logró con experiencias de laboratorio fijando las condiciones de cocción de acuerdo a la operación de los dig...

  5. Ozone bleaching of South African Eucalyptus grandis kraft pulps containing high levels of hexenuronic acids

    CSIR Research Space (South Africa)

    Andrew, JE

    2013-08-01

    Full Text Available Ozone use in conjunction with chlorine dioxide during pulp bleaching offers several advantages over conventional bleaching sequences that make use of chlorine dioxide only. Despite this, in South Africa, only one mill uses ozone. The current study...

  6. Integrating the processes of a Kraft pulp and paper mill and its supply chain

    International Nuclear Information System (INIS)

    Mesfun, Sennai; Toffolo, Andrea

    2015-01-01

    Highlights: • A process integration model that establishes material stream connections among typical Nordic forest industries is developed. • Potential benefit of the operating the different industries in one site is studied using pinch analysis. • Different scenarios considered to assess impact of prioritization on how to utilize excess biomass. • Results indicate large potential for improved biomass resource utilization. - Abstract: This paper investigates the possibility of combining different forest industries (a pulp and paper mill, its supply chain, and a wood-pellet plant) into an integrated industrial site in which they share a common heat and power utility. Advanced process integration and optimization techniques are used to study the site from both material and energy viewpoints. An existing pulp and paper mill is used as the site core plant and its pulp and paper production rates are kept fixed as they are in reality, while the other material flow links among the plants are based on the current industrial situation in Sweden. Different scenarios are evaluated in order to reflect the two main objectives that can be pursued (increased electricity production or biomass resource saving) and the two technologies that can be considered for the shared CHP system (boilers and product gas fired gas turbines). The corresponding non-integrated (standalone) configurations are compared to these scenarios to quantify the potential benefits of the integration. Investment opportunity is also calculated for the considered scenarios as an indicator of the economic convenience

  7. Consequent downsizing. Combined heat, cold and power generation; Konsequentes Downsizing. Kraft-Waerme-Kaelte-Kopplung

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Wolfgang

    2010-11-15

    The combined heat, cold and power generation particularly is worthwhile if electricity, warmth and cold are used during the year. During the reconstruction of a furniture store in a financial centre of the Volksbank and Raiffeisenbank Schweinfurt country (Federal Republic of Germany) the planner succeeded in an optimal coordination of the highly thermal insulated building envelope, the cogeneration plant for the own power generation, the absorption refrigerator as well as a free cooling equipment by means of a thermal building simulation and variational calculus.

  8. Economics evaluation for on-site pyrolysis of kraft lignin to value-added chemicals.

    Science.gov (United States)

    Farag, Sherif; Chaouki, Jamal

    2015-01-01

    This work is part of a series of investigations on pyrolysis of lignin. After obtaining the necessary information regarding the quantity and quality of the obtained products, a first step economics evaluation for converting lignin into chemicals was essential. To accomplish this aim, a pyrolysis plant with a 50t/d capacity was designed, and the total capital investment and operating costs were estimated. Next, the minimal selling price of the obtained dry oil was calculated and the effect of crucial variables on the estimated price was examined. The key result indicates the estimated selling price would not compete with the price of the chemicals that are fossil fuel based, which is primarily due to the high cost of the feedstock. To overcome this challenge, different scenarios for reducing the selling price of the obtained oil, which consequently is helping by taking a place among the fossil fuel based chemicals, were discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp.

    Science.gov (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

    2015-05-01

    Cellulase treatment for decreasing viscosity and increasing Fock reactivity of dissolving pulp is a promising approach to reduce the use of toxic chemicals, such as hypochlorite in the dissolving pulp manufacturing process in the industry. Improving the cellulase treatment efficiency during the process is of practical interest. In the present study, the concept of using cationic polyacrylamide (CPAM) to enhance the cellulase treatment efficiency was demonstrated. This was mainly attributed to the increased cellulase adsorption onto cellulose fibers based on the patching/bridging mechanism. Results showed that the cellulase adsorption was increased by about 20% with the addition of 250 ppm of CPAM under the same conditions as those of the control. It was found that the viscosity decrease and Fock reactivity increase for the cellulase treatment was enhanced from using CPAM. The CPAM-assisted cellulase treatment concept may provide a practical alternative to the present hypochlorite-based technology for viscosity control in the industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. High consistency cellulase treatment of hardwood prehydrolysis kraft based dissolving pulp.

    Science.gov (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

    2015-01-01

    For enzymatic treatment of dissolving pulp, there is a need to improve the process to facilitate its commercialization. For this purpose, the high consistency cellulase treatment was conducted based on the hypothesis that a high cellulose concentration would favor the interactions of cellulase and cellulose, thus improves the cellulase efficiency while decreasing the water usage. The results showed that compared with a low consistency of 3%, the high consistency of 20% led to 24% increases of cellulase adsorption ratio. As a result, the viscosity decrease and Fock reactivity increase at consistency of 20% were enhanced from 510 mL/g and 70.3% to 471 mL/g and 77.6%, respectively, compared with low consistency of 3% at 24h. The results on other properties such as alpha cellulose, alkali solubility and molecular weight distribution also supported the conclusion that a high consistency of cellulase treatment was more effective than a low pulp consistency process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Recycling cellulase towards industrial application of enzyme treatment on hardwood kraft-based dissolving pulp.

    Science.gov (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ji, Xingxiang; Ni, Yonghao

    2016-07-01

    Cost-effectiveness is vital for enzymatic treatment of dissolving pulp towards industrial application. The strategy of cellulase recycling with fresh cellulase addition was demonstrated in this work to activate the dissolving pulp, i.e. decreasing viscosity and increasing Fock reactivity. Results showed that 48.8-35.1% of cellulase activity can be recovered from the filtered liquor in five recycle rounds, which can be reused for enzymatic treatment of dissolving pulp. As a result, the recycling cellulase with addition fresh cellulase of 1mg/g led to the pulp of viscosity 470mL/g and Fock reactivity 80%, which is comparable with cellulase charge of 2mg/g. Other pulp properties such as alpha-cellulose, alkaline solubility and molecular weight distribution were also determined. Additionally, a zero-release of recycling cellulase treatment was proposed to integrate into the dissolving pulp production process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Die Kraft einer phänomenologischen Haltung. Reflexionen aus der Praxis des Religionsunterrichtes.

    Directory of Open Access Journals (Sweden)

    Joachim Hawel

    2014-07-01

    Full Text Available ENGLISH: Initially the terms ‚phenomenological‘ and ‚phenomenological attitude‘ respectively will be explicated. The phenomenological attitude is an attitude of mental and spiritual looking, which distinguishes between ‚feeling first‘ and ‚thinking later‘, it seeks to avoid, that, when problems in religious education class present themselves, by a rash assessment ‚That’s how it is‘ the personhood of the student and the personhood of the teacher are neglected. This attitude has several prerequisites, above all has to be the conscious decision for this attitude, which must be practiced and reflected a whole professional life. In the main part of the article six elements of a phenomenological attitude will be explained, the last of which relates to the ‚phenomenology of life‘ by Michel Henry, which points out, that the most essential part, namely life itself, is beyond visibility, which has drastic consequences for religious education – or any education for that matter. The ‚lifelong practicing‘ of this attitude also requires an extra occupational continuous development of the personality, which can also serve as burnout prophylaxis. DEUTSCH: Zunächst werden die Begriffe ‚phänomenologisch‘ bzw. ‚phänomenologische Haltung‘ expliziert. Die phänomenologische Haltung ist eine Haltung geistigen Schauens, die zwischen ‚Vor-Fühlen‘ und ‚Nach-Denken‘ unterscheidet, sie versucht zu vermeiden, dass man bei Problemen im Religionsunterricht durch die vorschnelle Feststellung ‚So ist es‘ das Person-Sein der SchülerInnen und das Person-Sein der Lehrenden außer Acht lässt. Diese Haltung hat mehrere Voraussetzungen, zuallererst bedarf es der bewussten Entscheidung für diese Haltung, die ein Berufsleben lang eingeübt bzw. reflektiert werden muss. Sechs Elemente einer phänomenologischen Haltung werden im Hauptteil des Artikels ausgeführt, das letzte Element bezieht sich auf die ‚Lebensphänomenologie‘ von Michel Henry, die aufweist, dass sich das Wesentliche, nämlich das Leben, der Sichtbarkeit entzieht, was für den Religionsunterricht - und für jeden andern Unterricht ebenso - einschneidende Konsequenzen hat. Das ‚lebenslange Einüben‘ dieser Haltung verlangt auch nach einer berufsbegleitenden kontinuierlichen Persönlichkeitsbildung, die unter anderem auch eine Burnout-Prophylaxe sein kann.

  13. Cogeneration and the regulatory framework of energy law; Kraft-Waerme-Kopplung und der energiewirtschaftliche Ordnungsrahmen

    Energy Technology Data Exchange (ETDEWEB)

    Cornehl, Angelika Bettina

    2009-06-15

    The present publication shows that the existing regulatory framework poses numerous impediments to cogeneration plants. This holds especially for industrial operators, but also for municipalities. It has prevented cogeneration from developing its full potential both as an element of competition and as a relief for the environment. Unlike industrial cogeneration plants, those serving the public energy supply at least enjoy the privilege of regional monopoly rights. In today's liberalised electricity market, however, this can be a burden for existing municipal plants which were installed under territorial protection and in many cases have incurred high cost levels and become inflexible and lacking in entrepreneurial spirit as a result. On account of its tendency to promote optimal resource input and efficiency, competition promises positive impulses for the use of cogeneration in small-scale heat grids, where high fuel efficiency matters more. A reform of the competition regime in the power economy would eliminate numerous impediments, particularly for industrial cogeneration operators. Good hopes for the future of cogeneration in a liberalised electricity and gas market are also nurtured by cooperative supply concepts and, within the large domain of services, opportunities held out by special contracting offers.

  14. Madera de compresión en Pinus radiata III: propiedades de pulpas kraft

    OpenAIRE

    Diaz-vaz,J.E; Ananias,R. A; Valenzuela,L; Torres,M; Rodriguez,S

    2012-01-01

    Estudios anteriores en estos mismos árboles de Pinus radiata con fustes levemente inclinados, demostraron que la madera de compresión leve que ellos exhibían presentaba: traqueidas más cortas, mayor densidad, mayor proporción de lignina, mayor proporción de extraíbles en etanol tolueno y menor proporción de alfa celulosa que la madera opuesta y que la madera de árboles sin madera de compresión. En el presente estudio se analiza las propiedades pulpables de la madera de compresión y la de sus ...

  15. Enzymatic pulp upgrade for producing high-value cellulose out of a Kraft paper pulp.

    Science.gov (United States)

    Hutterer, Christian; Kliba, Gerhard; Punz, Manuel; Fackler, Karin; Potthast, Antje

    2017-07-01

    The high-yield separation of polymeric parts from wood-derived lignocellulosic material is indispensable in biorefinery concepts. For the separation of cellulose and xylan from hardwood paper pulps to obtain pulps of high cellulose contents, simple alkaline extractions were found to be the most suitable technology, although having certain limitations. These are embodied by residual alkali resistant xylan incorporated in the pulp matrix. Further purification in order to produce pure cellulose with a low uniformity could be achieved selectively degrading residual xylan and depolymerizing the cellulose macromolecules by xylanase and cellulase. The latter help to adjust cellulose chain lengths for certain dissolving pulp grades while reducing the demand for ozone in subsequent TCF bleaching. Experiments applying different commercially available enzyme preparations revealed the dependency of xylanase performance on the residual xylan content in pulps being stimulated by additional cellulase usage. The action of the latter strongly depends on the cellulose allomorphy confirming the impact of the pulp morphology. Hence, the combined application of both types of enzymes offers a high potential for upgrading pulps in order to produce a pure and high-value cellulose product. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Potentials for heat accumulators in thermal power plants; Potenziale fuer Waermespeicher in Heiz(kraft)werken

    Energy Technology Data Exchange (ETDEWEB)

    Dengel, Andreas [STEAG New Energies GmbH, Saarbruecken (Germany)

    2012-07-01

    STEAG New Energies GmbH (Saarbruecken, Federal Republic of Germany) is contractor and operator of a variety of decentralized plants for heat production and power generation. The customers consist of communities, cooperation associations, business enterprises as well as industrial enterprises. Beside merely heat generators, so-called heat and power cogeneration plants often are used. The power generation is of minor importance due to the heat-controlled energy supply of the customers. Biomass power plants being operated in line with the Renewable Energy Law are an exemption. The demand for regulating energy increased clearly due to the enhanced volatile feeding of regenerative produced electric power. If the operation of heat and power cogeneration plants becomes more independent from the actual energy demand by using energy storages, then the energy transducer can be implemented in the lucrative market of regulation energy supply. Thus, the potential of such storages at the sites within a company shall be determined. Additionally, the development and testing of a latent heat accumulator for a thermal power plant of the company supplying process vapour with a temperature of 300 Celsius to a foil manufacturing facility is envisaged.

  17. Production development on the Norwegian continental shelf; KonKraft rapport 2; Produksjonsutviklingen paa norsk sokkel

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    After almost 40 years of virtually uninterrupted growth, total hydrocarbon production on the Norwegian continental shelf (NCS) has reached its highest level ever, with a daily output of 4-4.5 million barrels of oil equivalent per day. It is expected to remain at this level for the next 7 years. After 2015 or thereabouts, however, total oil and gas production is forecast to start declining. Oil production is already falling. Gas output has been increasing, but this is not expected to continue offsetting the drop in liquid production beyond 2015 or thereabouts if no action is taken. Only half the combined oil and gas resources predicted by the Norwegian Petroleum Directorate (NPD) will have been produced in 2015. Remaining recoverable resources, including those expected to be found by further exploration, are currently estimated to be 38-77 billion barrels of oil equivalent (boe). This estimate could be 25-65 billion boe in 2015. Only 40 per cent of the total expected remaining hydrocarbon resources remains to be discovered today, which explains the wide range in the estimates. This huge potential must be managed well to avoid a sharp decline in production and to support a healthy level of long-term investment. The report on production development on the Norwegian continental shelf is published at a time when major changes are taking place both inside and outside the petroleum industry. Several factors make a review of what can be done to address the production decline particularly urgent. Although the current level of activity in the Norwegian petroleum sector is high, assessing the long-term perspectives for the industry is very important. In many cases, the period between the award of licences and the start of production can be 15 years or more. Decisions taken now may have important implications for levels of production and activity in the 2020s. (Author)

  18. 40 CFR 63.446 - Standards for kraft pulping process condensates.

    Science.gov (United States)

    2010-07-01

    ... National Emission Standards for Hazardous Air Pollutants from the Pulp and Paper Industry § 63.446...; (3) Each evaporator system condensate from: (i) The vapors from each stage where weak liquor is introduced (feed stages); and (ii) Each evaporator vacuum system for each stage where weak liquor is...

  19. Carbon distribution in char residue from gasification of kraft black liquor

    International Nuclear Information System (INIS)

    Sricharoenchaikul, Viboon; Frederick, W.J.; Agrawal, Pradeep

    2003-01-01

    The char residue yields and the total carbon and carbonate content were measured for dry black liquor solids after pyrolysis or gasification in a laminar entrained-flow reactor. The experimental conditions were 700-1000 deg. C in N 2 ,CO 2 /N 2 or water vapor/N 2 at 1 bar total pressure, for residence times from 0.3 to 1.7 s. Fixed carbon yields, when measured at the same particle residence time, decreased with increasing reactor temperature. CO 2 and water vapor diminished the char carbon significantly at temperatures above 800 deg. C, compared with pyrolysis in N 2 . Water vapor oxidized the char carbon more rapidly than did CO 2 . At 1000 deg. C, the reactions of carbon with sulfate and carbonate became faster, resulting in a smaller difference between carbon conversion rates in the different gas environments. By the end of devolatilization, the amount of carbonate in the char had changed very little at 700-800 deg. C. After devolatilization, carbonate was formed more rapidly at higher temperatures. The presence of CO 2 or water vapor increased the formation of carbonate. In the presence of these gases, more carbonate was measured at all temperatures and residence times. The maximum carbonate measured in the char was 16% of the carbon in the black liquor solids, as compared to 4.4% in the original dry liquor solids. Under most conditions, the carbonate, as a fraction of carbon input, first increased to a constant, temperature-independent value and then decreased

  20. Energy Balance and Performance Indices for Kraft Recovery Boilers; Standardmetod foer beraekning av energibalans oever sodapanna

    Energy Technology Data Exchange (ETDEWEB)

    Kjoerk, Anders

    2007-09-15

    It has been recognized that different rules exist in calculating energy flows to and from a Recovery boiler. In this report definitions are given with the intention that the branch should adopt a common position in reporting power production for the Swedish system with charge on emission of nitrogen oxides, for the EU Emissions Trading Scheme and for the electricity certificate system. Legislation and guidelines are described as also different standards for determination of boiler efficiency. The definition of the liquor heating value is discussed as also the different ways in which an energy balance could be set up. For the Emissions Trading Scheme a literature survey of interpretations made in other countries has been made. The recommendation is to define the heat input as the product of the virgin liquor flow and the net calorific value of virgin liquor. A net calorific value as defined in SS-ISO 1928 is determined in an environment with excess of oxygen and is consequently named net calorific value in oxidizing condition. In a Recovery boiler part of that heat is required for reduction of sulfur and a net calorific value in reducing condition are therefore defined in a branch specific way. The flow of liquor could be calculated using a heat balance based on steam generation. The envelope for that heat balance could be selected as to fit each individual installation; however some general recommendations are given. In reporting energy flow for the EU Emissions Trading Scheme and to EPA it is recommended to use the net calorific value in oxidizing condition. This definition should also be good for reporting to Statistics Sweden, Swedish Forest Industries Federation and for internal use. For reporting to the electricity certificate system the part of the total power production with origin from biofuel should be stated. The heat of reduction is not available for power production and consequently the recommendation is to use the net calorific value in reducing condition. The useful energy production as defined in the system for charge on nitrogen oxides is more intricate to define. Today Recovery boilers are not included in the system but it has been proposed from EPA to widen the system and also include them. For this system a definition is suggested where energy required for sulfur reduction as well as energy in produced high pressure steam are included. Heat reclaimed in flue gas scrubber, vent gas condenser or similar type of equipment should also be included.

  1. Equal treatment for new renewable heating and power; Likebehandling av ny fornybar varme og kraft

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-12-20

    If a system of electric certificates is established in Norway, adjustments in the conditions of competition will need to be made for green heating production, assuring that green heating does not lose in the competition with green electricity (el). To ensure that the terms of competition are as equal as possible the most efficient policy instrument is to include heating in a common certificate system for el and heating. If it is not possible to establish a common system of certificates, the best policy instrument will be to ensure equal conditions of competition.

  2. Precipitation and valorisation of lignin obtained from South African Kraft mill black liquor

    CSIR Research Space (South Africa)

    Namane, Mpho

    2016-04-01

    Full Text Available (NMR), size exclusion chromatography (SEC), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). SEC data revealed a narrow molecular weight distribution with a small polydispersity index in the lignin sample – all desirable features...

  3. Kraft pulp and paper mill wastewater treatment using fixed bed anaerobic reactors

    International Nuclear Information System (INIS)

    Damianovic, M. H. R. Z; Ruas, D.; Pires, E. C.; Foresti, E.

    2009-01-01

    The effluents of pulp mills contain a myriad of toxic compounds, biodegradable organic matter and sulfur compounds. to decrease the amount of fresh water required for pulp and paper production closed circuits are in use, however, higher concentrations of slat, as oxidized sulfur compounds, are encountered in the wastewaters. energy costs and new environmental concerns are motivating the use of anaerobic pretreatment as a way to decrease energy expenditure in the treatment plant together with lower sludge production. In anaerobic environment, the organic matter removal can follow methanogenic or sulfidogenic paths and with the latter simultaneous reduction of the oxidized sulfur compounds also occurs. (Author)

  4. Biofilms from micro/nanocellulose of NaBH4-modified kraft pulp

    Indian Academy of Sciences (India)

    2017-07-26

    Jul 26, 2017 ... 2Polymer Engineering Department, Faculty of Technology, Duzce University, 81620 Duzce, .... performed in a plastic bag, which was placed in a water bath .... double air-bearing probe and a zirconium oxide rotor (4 mm).

  5. Chemical pulping of waste pineapple leaves fiber for kraft paper production

    Directory of Open Access Journals (Sweden)

    Waham Ashaier Laftah

    2015-07-01

    Full Text Available The main objective of this study is to evaluate the implementation of acetone as a pulping agent for pineapple leaves. Mixtures of water and acetone with concentration of 1%, 3%, 5%, 7%, and 10% were used. The effects of soaking and delignification time on the paper properties were investigated. Thermal and physical properties of paper sheet were studied using thermogravimetric analysis (TGA and tearing resistance test respectively. The morphological properties were observed using microscope at 200× magnification. The paper sheet produced from pulping with 3% acetone concentration shows the highest mechanical properties. Papers strength was improved by increasing the delignification time. The delignification time was reduced by cooking the pineapple leaves at a temperature of 118 °C under applied pressure of 80 kPa which has remarkable effect on paper strength.

  6. Chemical pulping of waste pineapple leaves fiber for kraft paper production

    OpenAIRE

    Laftah, Waham Ashaier; Abdul Rahaman, Wan Aizan Wan

    2015-01-01

    The main objective of this study is to evaluate the implementation of acetone as a pulping agent for pineapple leaves. Mixtures of water and acetone with concentration of 1%, 3%, 5%, 7%, and 10% were used. The effects of soaking and delignification time on the paper properties were investigated. Thermal and physical properties of paper sheet were studied using thermogravimetric analysis (TGA) and tearing resistance test respectively. The morphological properties were observed using microscope...

  7. Enzymatic Transesterification of Kraft Lignin with Long Acyl Chains in Ionic Liquids

    OpenAIRE

    Hulin, Lise; Husson, Eric; Bonnet, Jean-Pierre; Stevanovic, Tatjana; Sarazin, Catherine

    2015-01-01

    Valorization of lignin is essential for the economic viability of the biorefinery concept. For example, the enhancement of lignin hydrophobicity by chemical esterification is known to improve its miscibility in apolar polyolefin matrices, thereby helping the production of bio-based composites. To this end and due to its many reactive hydroxyl groups, lignin is a challenging macromolecular substrate for biocatalyzed esterification in non-conventional media. The present work describes for the f...

  8. Spectroscopic determination of anthraquinone in kraft pulping liquors using a membrane interface

    Science.gov (United States)

    X.S. Chai; X.T. Yang; Q.X. Hou; J.Y. Zhu; L.-G. Danielsson

    2003-01-01

    A spectroscopic technique for determining AQ in pulping liquor was developed to effectively separate AQ from dissolved lignin. This technique is based on a flow analysis system with a Nafion membrane interface. The AQ passed through the membrane is converted into its reduced form, AHQ, using sodium hydrosulfite. AHQ has distinguished absorption characteristics in the...

  9. Stirred cell ultrafiltration of lignin from black liquor generated from South African kraft mills

    CSIR Research Space (South Africa)

    Kekana, Paul

    2016-12-01

    Full Text Available Ultrafiltration of lignin from black liquor was carried out in a stirred batch cell using polyethersulfone membranes. Parameters such as operating pressure, feed concentration, stirring rate and membrane cut-off size were varied and their effects...

  10. Controlling Barium Sulphate Scale Deposition Problems in an unbleached Kraft Paper Mill

    CSIR Research Space (South Africa)

    Sithole, Bruce

    2015-06-01

    Full Text Available Troubleshooting of scale deposits and defects in paper samples showed that the problem was caused by barium sulphate and calcium sulphate scales. However, it was ascertained that barium sulphate was more of a concern than calcium sulphate...

  11. A comprehensive program to develop correlations for physical properties of kraft black liquor. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, A.L.; Zaman, A.A.; Stoy, M.O.; Schmidl, G.W.; Dong, D.J.; Speck, B.

    1998-04-01

    A wide variety of experimental techniques have been used in this work, and many of these have been developed completely or improved significantly in the course of the research done during this program. Therefore, it is appropriate to describe these techniques in detail as a reference for future workers so that the techniques can be used in future work with little additional effort or so that the results reported from this program can be compared better with future results from other work. In many cases, the techniques described are for specific analytical instruments. It is recognized that these may be superseded by future developments and improvements in instrumentation if a complete description of techniques used successfully in the past on other instrumentation is available. The total pulping and liquor preparation research work performed included chip and white liquor preparation, digestion, pulp washing, liquor and wash recovery, liquor sampling, weak liquor concentration in two steps to about 45--50% solids with an intermediate soap skimming at about 140F and 27--30% solids, determination of pulp yield and Kappa number, determination of total liquor solids, and a check on the total material balance for pulping. All other research was performed either on a sample of the weak black liquor (the combined black liquor and washes from the digester) or on the skimmed liquor that had been concentrated.

  12. Techno-economic evaluation of stillage treatment with anaerobic digestion in a softwood-to-ethanol process

    Directory of Open Access Journals (Sweden)

    Barta Zsolt

    2010-09-01

    Full Text Available Abstract Background Replacing the energy-intensive evaporation of stillage by anaerobic digestion is one way of decreasing the energy demand of the lignocellulosic biomass to the ethanol process. The biogas can be upgraded and sold as transportation fuel, injected directly into the gas grid or be incinerated on-site for combined heat and power generation. A techno-economic evaluation of the spruce-to-ethanol process, based on SO2-catalysed steam pretreatment followed by simultaneous saccharification and fermentation, has been performed using the commercial flow-sheeting program Aspen Plus™. Various process configurations of anaerobic digestion of the stillage, with different combinations of co-products, have been evaluated in terms of energy efficiency and ethanol production cost versus the reference case of evaporation. Results Anaerobic digestion of the stillage showed a significantly higher overall energy efficiency (87-92%, based on the lower heating values, than the reference case (81%. Although the amount of ethanol produced was the same in all scenarios, the production cost varied between 4.00 and 5.27 Swedish kronor per litre (0.38-0.50 euro/L, including the reference case. Conclusions Higher energy efficiency options did not necessarily result in lower ethanol production costs. Anaerobic digestion of the stillage with biogas upgrading was demonstrated to be a favourable option for both energy efficiency and ethanol production cost. The difference in the production cost of ethanol between using the whole stillage or only the liquid fraction in anaerobic digestion was negligible for the combination of co-products including upgraded biogas, electricity and district heat.

  13. Techno-economic evaluation of stillage treatment with anaerobic digestion in a softwood-to-ethanol process.

    Science.gov (United States)

    Barta, Zsolt; Reczey, Kati; Zacchi, Guido

    2010-09-15

    Replacing the energy-intensive evaporation of stillage by anaerobic digestion is one way of decreasing the energy demand of the lignocellulosic biomass to the ethanol process. The biogas can be upgraded and sold as transportation fuel, injected directly into the gas grid or be incinerated on-site for combined heat and power generation. A techno-economic evaluation of the spruce-to-ethanol process, based on SO2-catalysed steam pretreatment followed by simultaneous saccharification and fermentation, has been performed using the commercial flow-sheeting program Aspen Plus™. Various process configurations of anaerobic digestion of the stillage, with different combinations of co-products, have been evaluated in terms of energy efficiency and ethanol production cost versus the reference case of evaporation. Anaerobic digestion of the stillage showed a significantly higher overall energy efficiency (87-92%), based on the lower heating values, than the reference case (81%). Although the amount of ethanol produced was the same in all scenarios, the production cost varied between 4.00 and 5.27 Swedish kronor per litre (0.38-0.50 euro/L), including the reference case. Higher energy efficiency options did not necessarily result in lower ethanol production costs. Anaerobic digestion of the stillage with biogas upgrading was demonstrated to be a favourable option for both energy efficiency and ethanol production cost. The difference in the production cost of ethanol between using the whole stillage or only the liquid fraction in anaerobic digestion was negligible for the combination of co-products including upgraded biogas, electricity and district heat.

  14. 75 FR 52453 - Entry Requirements for Certain Softwood Lumber Products Exported From Any Country Into the United...

    Science.gov (United States)

    2010-08-26

    ...)(3)(iii)(B)(3), which states that ``the exporter has paid, or committed to pay, all export charges..., to his best knowledge and belief, that the exporter has paid or committed to pay ``all export charges... discrepancies between the export permit date and the entry summary data. The commenter suggests using the...

  15. Comparative technoeconomic analysis of a softwood ethanol process featuring posthydrolysis sugars concentration operations and continuous fermentation with cell recycle.

    Science.gov (United States)

    Schneiderman, Steven J; Gurram, Raghu N; Menkhaus, Todd J; Gilcrease, Patrick C

    2015-01-01

    Economical production of second generation ethanol from Ponderosa pine is of interest due to widespread mountain pine beetle infestation in the western United States and Canada. The conversion process is limited by low glucose and high inhibitor concentrations resulting from conventional low-solids dilute acid pretreatment and enzymatic hydrolysis. Inhibited fermentations require larger fermentors (due to reduced volumetric productivity) and low sugars lead to low ethanol titers, increasing distillation costs. In this work, multiple effect evaporation (MEE) and nanofiltration (NF) were evaluated to concentrate the hydrolysate from 30 g/l to 100, 150, or 200 g/l glucose. To ferment this high gravity, inhibitor containing stream, traditional batch fermentation was compared with continuous stirred tank fermentation (CSTF) and continuous fermentation with cell recycle (CSTF-CR). Equivalent annual operating cost (EAOC = amortized capital + yearly operating expenses) was used to compare these potential improvements for a local-scale 5 MGY ethanol production facility. Hydrolysate concentration via evaporation increased EAOC over the base process due to the capital and energy intensive nature of evaporating a very dilute sugar stream; however, concentration via NF decreased EAOC for several of the cases (by 2 to 15%). NF concentration to 100 g/l glucose with a CSTF-CR was the most economical option, reducing EAOC by $0.15 per gallon ethanol produced. Sensitivity analyses on NF options showed that EAOC improvement over the base case could still be realized for even higher solids removal requirements (up to two times higher centrifuge requirement for the best case) or decreased NF performance. © 2015 American Institute of Chemical Engineers.

  16. Comparative effect of mechanical beating and nanofibrillation of cellulose on paper properties made from bagasse and softwood pulps.

    Science.gov (United States)

    Afra, Elyas; Yousefi, Hossein; Hadilam, Mohamad Mahdi; Nishino, Takashi

    2013-09-12

    Cellulose fibers were fibrillated using mechanical beating (shearing refiner) and ultra-fine friction grinder, respectively. The fibrillated fibers were then used to make paper. Mechanical beating process created a partial skin fibrillation, while grinding turned fiber from micro to nanoscale through nanofibrillation mechanism. The partially fibrillated and nano fibrillated fibers had significant effects on paper density, tear strength, tensile strength and water drainage time. The effect of nanofibrillation on paper properties was quantitatively higher than that of mechanical beating. Paper sheets from nanofibrillated cellulose have a higher density, higher tensile strength and lower tear strength compared to those subjected to mechanical beating. Mechanical beating and nanofibrillation were both found to be promising fiber structural modifications. Long water drainage time was an important drawback of both fibrillation methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. High-speed double-disc TMP [thermomechanical pulp] from northern and southern softwoods: One or two refining stages

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, M.J. (Andritz Sprout-Bauer, Inc., Springfield, OH (United States)); Cort, J.B.; Musselman, R.L. (Andritz Sprout-Bauer, Inc., Muncy, PA (United States))

    1994-01-01

    Pilot-plant studies were carried out to evaluate one- and two-stage high-speed refining processes for production of thermomechanical pulp (TMP) at minimal energy consumption. Both northern (black spruce/balsam fir) and southern (lobolly pine) wood species were tested. Preliminary results indicate both one- and two-stage high-speed refining are suitable for the production of TMP from spruce and fir. Single-stage, high-speed refining of spruce/fir resulted in over 25% energy savings compared to conventional TMP production. The resulting TMP had improved optical and shive content properties, with slightly reduced pulp strength and long fiber content. Two stages of refining were necessary to optimize pulp quality from the lobolly pine furnish. A 15% energy reduction was obtained when comparing high-speed and conventional TMP pulping of lobolly pine at similar operating conditions. The high-speed pine TMP had comparable bonding strength, shive content, and lower tear than conventional two-stage lobolly pine TMP. 14 refs., 11 figs., 6 tabs.

  18. High Selectivity Oxygen Delignification

    Energy Technology Data Exchange (ETDEWEB)

    Arthur J. Ragauskas

    2005-09-30

    The overall objective of this program was to develop improved extended oxygen delignification (EOD) technologies for current U.S. pulp mill operations. This was accomplished by: (1) Identifying pulping conditions that optimize O and OO performance; (2) Identifying structural features of lignin that enhance reactivity towards EOD of high kappa pulps; (3) Identifying factors minimizing carbohydrate degradation and improve pulp strength of EOD high kappa pulps; (4) Developing a simple, reproducible method of quantifying yield gains from EOD; and (5) Developing process conditions that significantly reduce the capital requirements of EOD while optimizing the yield benefits. Key research outcomes included, demonstrating the use of a mini-O sequence such as (E+O)Dkf:0.05(E+O) or Dkf:0.05(E+O)(E+O) without interstage washing could capture approximately 60% of the delignification efficiency of a conventional O-stage without the major capital requirements associated with an O-stage for conventional SW kraft pulps. The rate of formation and loss of fiber charge during an O-stage stage can be employed to maximize net fiber charge. Optimal fiber charge development and delignification are two independent parameters and do not parallel each other. It is possible to utilize an O-stage to enhance overall cellulosic fiber charge of low and high kappa SW kraft pulps which is beneficial for physical strength properties. The application of NIR and multi-variant analysis was developed into a rapid and simple method of determining the yield of pulp from an oxygen delignification stage that has real-world mill applications. A focus point of this program was the demonstration that Kraft pulping conditions and oxygen delignification of high and low-kappa SW and HW pulps are intimately related. Improved physical pulp properties and yield can be delivered by controlling the H-factor and active alkali charge. Low AA softwood kraft pulp with a kappa number 30 has an average improvement of 2% in

  19. Production and characterization of thermostable xylanase from ...

    African Journals Online (AJOL)

    ajl2

    2013-02-20

    Feb 20, 2013 ... produced from Trichoderma (Huitron et al., 2008). Only a ... around their colonies against a red background, were selected and .... Resistance to antibiotic ..... Xylanases of marine fungi potential use for biobleaching of paper.

  20. Phoenix dactylifera L.

    African Journals Online (AJOL)

    USER

    2010-05-31

    May 31, 2010 ... their use for flavoring foods, beverages and medication. (Vayalil, 2002). Minerals are .... Potassium is vital to cellular integrity and fluid balance as it plays an important role in .... mechanical pulp for bio-bleaching. Food Chem.

  1. Mill Designed Bio bleaching Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Institute of Paper Science Technology

    2004-01-30

    A key finding of this research program was that Laccase Mediator Systems (LMS) treatments on high-kappa kraft could be successfully accomplished providing substantial delignification (i.e., > 50%) without detrimental impact on viscosity and significantly improved yield properties. The efficiency of the LMS was evident since most of the lignin from the pulp was removed in less than one hour at 45 degrees C. Of the mediators investigated, violuric acid was the most effective vis-a-vis delignification. A comparative study between oxygen delignification and violuric acid revealed that under relatively mild conditions, a single or a double LMS{sub VA} treatment is comparable to a single or a double O stage. Of great notability was the retention of end viscosity of LMS{sub VA} treated pulps with respect to the end viscosity of oxygen treated pulps. These pulps could then be bleached to full brightness values employing conventional ECF bleaching technologies and the final pulp physical properties were equal and/or better than those bleached in a conventional ECF manner employing an aggressively O or OO stage initially. Spectral analyses of residual lignins isolated after LMS treated high-kappa kraft pulps revealed that similar to HBT, VA and NHA preferentially attack phenolic lignin moieties. In addition, a substantial decrease in aliphatic hydroxyl groups was also noted, suggesting side chain oxidation. In all cases, an increase in carboxylic acid was observed. Of notable importance was the different selectivity of NHA, VA and HBT towards lignin functional groups, despite the common N-OH moiety. C-5 condensed phenolic lignin groups were overall resistant to an LMS{sub NHA, HBT} treatments but to a lesser extent to an LMS{sub VA}. The inactiveness of these condensed lignin moieties was not observed when low-kappa kraft pulps were biobleached, suggesting that the LMS chemistry is influenced by the extent of delignification. We have also demonstrated that the current

  2. SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS RECOVERY BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

    Science.gov (United States)

    Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

  3. Kundutredning av deltagande företag i IndustriForums Lean krAft utbildning 2005-2006

    OpenAIRE

    Gustavsson, Jonas

    2006-01-01

    This essay is an enquiry about how companies as participated in a Lean pro¬duction education use this education. The essay describes also how one works with the implementation of Lean production and how they believe that they will work. The enquiry tries to create an advisory material for other companies that are in the beginning of implementing their own Lean production systems. There these companies’ gets a picture of how other companies have done during their try to create a functioning Le...

  4. Efficient use of green taxes in the CHP sector; Effektiv brug af groenne afgifter i kraft- og varmesektoren

    Energy Technology Data Exchange (ETDEWEB)

    Skovsgaard Nielsen, L.; Mognesen, Martin Frank; Pade, L.L.

    2007-06-15

    Since 1977 green taxes have been used in the Danish power and heat sector. Green taxes principally assure an efficient, market-based reduction of pollution by reducing the energy consumption or increasing the share of renewable energy in power and heat production. This report takes its point of departure in four potential barriers which prevent a marketbased, cost-effective increase of the proportion of renewable energy in power and heat production. We primarily concentrate on three policy measures. 5. green and lessgreen taxes; 6. mandatory combined heat and power production; 7. fuel restrictions. Furthermore, we analyse a fourth characteristic in the law: 8. high transactions costs connected to the enlargement of renewable energy. The purpose of the report is to describe how the four potential barriers contradict the theoretically efficient application of green taxes in the power and heat sector. We do this: 1) by clarifying how legislation in the power and heat sector affects the extension of renewable energy; and 2) by evaluating the theoretically efficient application of green taxes in the power and heat sector in relation to legislation. (au)

  5. Furfural formation from the pre-hydrolysis liquor of a hardwood kraft-based dissolving pulp production process.

    Science.gov (United States)

    Liu, Haitang; Hu, Huiren; Jahan, M Sarwar; Ni, Yonghao

    2013-03-01

    This study aimed to produce furfural from the PHL. Results showed best furfural yield of 32.8% and the furfural selectivity of 37.7% in the monophase system (170 °C, 100 min), while they were 60.1% and 69.8%, respectively in the biphase system. The lower furfural selectivity in the monophase system was explained by more side reactions, such as fragmentation, condensation reactions, resinification and others. Model compounds such as: xylose, furfural, syringaldehyde, were used to confirm/identify these side reactions. The addition of dilute sulfuric acid/acetic acid in the system under the same conditions decreased the recovery of furfural. The addition of syringaldehyde into the PHL also led to a decrease in the furfural yield, supporting the conclusion that lignin structures in the PHL may also be involved in the side reactions, thus decreasing the furfural yield. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Driving force behind all. The history of energy uses in the world. Die alles treibende Kraft. Weltgeschichte der Energie

    Energy Technology Data Exchange (ETDEWEB)

    Zischka, A.

    1988-01-01

    The book reviews the history of energy uses in the world, arranging the material into three main sections corresponding to the three historical revolutions in the development of man's capacity to use the energy available in the world for his own purposes. These three mile posts are the mastering and utilization of fire, the Neolithic revolution, and the industrial revolution. The author tells the story excitingly and in a fascinating way explaining the very first steps and the long way mankind took, to achieve the technological systems we have now. Concentrating on the developments and interactions of significance to today's situation, the author presents data and information that brings life into history and fosters independent thinking. Right answers need the right questions, so the author tries to find out what has become indispensable for us, since when we have it, and who found it, and why, and what the consequences are for the present generation. The author mentions the persons, their biographies, and their achievements, showing that all knowledge and success was achieved by hard work.

  7. Testing of a Stirling engine for heat + power cogeneration; Test eines Stirlingmotors zur Kraft-Waerme-Kopplung

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, M.; Heinen, J. [RWE Energy AG, Essen (Germany)

    2007-01-15

    As part of a technology evaluation of distributed energy generators, RWE Energy AG extensively tested a micro combined heat and power appliance, powered by a Stirling engine developed by the British firm Microgen Energy Limited. Microgen Energy Limited is a specialist in micro combined heat and power (microCHP) based on unique Free-Piston Stirling generator technology Microgen is working with leading appliance manufacturers to integrate its core technology into a range of innovative microCHP products. The investigations concentrated on the determination of capacity, efficiency and emissions, the grid connection and behaviour at start-up and under varying loads. This article summarises the results of the tests and gives an overview of micro-CHP technologies (CHP=combined heat and power) and their possible significance to the market in the future. (orig.)

  8. Kenneth Kraft, Budismo solidario. Un nuevo mapa del sendero, Editorial Maitri, Santiago de Chile, 2001, 106 p.

    OpenAIRE

    Gottlieb, Teresa

    2012-01-01

    El budismo actual presenta dos grandes ramas. La más antigua es la hinayana, el “pequeño vehículo”, representado actualmente por la escuela Theravada, arraigada fundamentalmente en Birmania, Laos, Tailandia, Camboya, Sri Lanka y Malasia. La otra, es el budismo mahayánico, el “gran vehículo”, surgido en el siglo segundo antes de nuestra era, y característico de China, Mongolia, Corea,  Tíbet y Japón, y de la cual el budismo zen es una de su principales expresiones. La escuela Theravada tiene c...

  9. Combined heat and power and thermally insulating measures in residential housing stock; Kraft-Waerme-Kopplung und Daemmmassnahmen im Wohngebaeudebestand

    Energy Technology Data Exchange (ETDEWEB)

    Buller, Michael [Gas- und Waerme-Institut Essen e.V., Essen (Germany)

    2013-02-15

    The author of the contribution under consideration reports on the economic, ecologic and primary energetic potential of micro-combined heat and power (micro-CHP) in the residential housing stock under consideration of possible correlations between CHP and thermally insulating measures.

  10. Anaerobic biodegradability and toxicity of wastewaters from chlorine and total chlorine-free bleaching of eucalyptus kraft pulps.

    NARCIS (Netherlands)

    Vidal, G.; Soto, M.; Field, J.; Mendez-Pampin, R.; Lema, J.M.

    1997-01-01

    Chlorine bleaching effluents are problematic for anaerobic wastewater treatment due to their high methanogenic toxicity and low biodegradability. Presently, alternative bleaching processes are being introduced, such as elemental chlorine-free (ECF) and total chlorine-free (TCF) bleaching. The

  11. 40 CFR Appendix E to Part 63 - Monitoring Procedure for Nonthoroughly Mixed Open Biological Treatment Systems at Kraft Pulp...

    Science.gov (United States)

    2010-07-01

    ..., including methods, locations, and times; (3) A description of what conditions (DO, temperature, etc.) are... conditions. The purpose of this procedure is to estimate the concentration of HAP within the open biological... locations of the unit. This procedure may be used only under unsafe sampling conditions to estimate fbio...

  12. East German power plants: New concepts for the power and energy supply; Ostdeutscher Kraftwerkspark: Neugestaltung der Kraft- und Waermeversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Bald, A [Fossil Befeuerte Kraftwerke Inland, Bereich Energieerzeugung (KWU), Siemens AG (Germany)

    1994-10-01

    The enhancement of the energy economy plays the key role for the economic and ecological sanitation of the New Laender. Due to the bad condition sanitation mostly means new construction. The energy economy, the manufacturing industry and the public administration have successfully met this challenge. The programme has been launched, nearly all key projects have been given to contractors, the majority has already been realised and the first plants have already been connected to the network. Due to the performance that has been achieved so far, the following statement can already be made today. At the end of the decade the New Laender will have the most modern power and thermal energy supply in the world. Hence the industrial site eastern Germany gains an attractiveness that does not have to fear the international competition. Apart from strong impetus for economic growth and employment the environmentally friendly energy supply will lead to a considerable improvement of the life quality of approx. 16 million people. (orig.) [Deutsch] Bei der oekonomischen und oekologischen Gesundung der neuen Bundeslaender faellt der Sanierung der Energiewirtschaft eine Schluesselrolle zu. Wegen der schlechten Substanz kann Sanierung zumeist nur Neubau heissen. Dieser Herausforderung haben sich Energiewirtschaft, Herstellerindustrie und oeffentliche Verwaltung erfolgreich gestellt. Das Ausbauprogramm ist auf den Weg gebracht, fast alle Schluesselprojekte sind vergeben, die meisten mittlerweile in der Realisierung, und die ersten Anlagen sind sogar schon am Netz. Angesichts des bisher Geleisteten laesst sich bereits heute feststellen: Ende des Jahrzehnts werden die neuen Bundeslaender ueber die modernste Strom- und Waermeversorgung der Welt verfuegen. Der Wirtschaftsstandort Ostdeutschland gewinnt damit eine Attraktivitaet, die international keinen Vergleich zu scheuen braucht. Neben kraeftigen Wachstums- und Beschaeftigungsimpulsen wird der umweltfreundliche Neuaufbau der Energieversorgung eine spuerbare Verbesserung der Lebensqualitaet fuer die hier lebenden rund 16 Mio Mitbuerger bringen. (orig.)

  13. Qualidade da madeira de eucalipto e Acacia mangium consorciadas para produção de polpa kraft branqueada

    OpenAIRE

    Lombardi, Lucas Recla

    2013-01-01

    Objetivou-se com esse estudo a avaliação da qualidade da madeira de Acacia mangium cultivada no Brasil em consórcio com o híbrido Eucalyptus urophylla X Eucalyptus grandis para a produção de celulose branqueada e papel. Para tanto, avaliou-se efeitos de diferentes proporções de plantio misto, sendo totalizados quatro tratamentos caracterizados pela relação árvores de Acácia e árvores de Eucalipto plantadas no talhão. A qualidade da madeira foi analisada por meio da análise da composição quími...

  14. Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips

    CSIR Research Space (South Africa)

    Andrew, JE

    2014-01-01

    Full Text Available -ability. Savings in chlorine dioxide for PHK pulps ranged between 2-18% for sequences that used chlorine dioxide as the primary oxidative bleaching chemical. When ozone was used in combination with chlorine dioxide, mixed results were obtained – PHK pulps showed...

  15. Process design and economics of a flexible ethanol-butanol plant annexed to a eucalyptus kraft pulp mill.

    Science.gov (United States)

    Pereira, Guilherme C Q; Braz, Danilo S; Hamaguchi, Marcelo; Ezeji, Thaddeus C; Maciel Filho, Rubens; Mariano, Adriano P

    2018-02-01

    This work proposes a strategy, from a process design standpoint, for pulp companies to enter the Brazilian ethanol market. The flexible plant converts eucalyptus-derived glucose to either ethanol or butanol (according to market conditions) and xylose only to butanol production. Depending on the biomass pretreatment technology, Monte Carlo simulations showed that the Net Present Value (NPV) of the flexible plant increases by 20-28% in relation to an ethanol-dedicated plant. Whereas the lower costs of the steam explosion technology turns the investment more attractive (NPV = 184 MMUSD; IRR = 29%), the organosolv technology provides better flexibility to the plant. This work also shows that excessive power consumption is a hurdle in the development of flash fermentation technology chosen for the flexible plant. These results indicate that conventional batch fermentation is preferable if the enzymatic hydrolysis step operates with solids loading up to 20 wt%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The optimal scheduling of decentralised co-generation plants in microgrids; Optimale Einsatzplanung von Kraft-Waerme-Kopplungsanlagen in Microgrids

    Energy Technology Data Exchange (ETDEWEB)

    Gunkel, David [TU Dresden (Germany). Lehrstuhl fuer Energiewirtschaft; Hess, Tobias; Schegner, Peter [TU Dresden (Germany). Inst. fuer Elektrische Energieversorgung und Hochspannungstechnik

    2011-07-01

    The daily operational scheduling of decentralised unit is an important optimization task of power systems. This proceeding deals with planning of small scaled co-generation power units for district heating in a microgrid. This power system can be mathematically formulated and solved by an optimization algorithm. The solution process consists of a unit commitment and dispatch. The starting unit commitment is characterised by a mixed integer nonlinear problem defining the on-off-state of all units. Subsequently, the dispatch distributes the generation requirements to every committed unit considering thermal demand. The dispatching is based on a mixed integer linear problem. Additionally, it presents a way for flexible reducing the outage reserve related to the operational condition. The given microgrid operates in an islanding mode. The method can also be applied in a grid connected model considering the possible requirements of a grid operator. (orig.)

  17. Two-stage absorber systems - Economically viable combined heat and cold generation; Wirtschaftlicher Kraft-Waerme-Kaelte-Verbund

    Energy Technology Data Exchange (ETDEWEB)

    Biniossek, H. [Giesecke und Devrient, Muenchen (Germany); Schmid, W. [Technische Gebaeudeausruestung, Muenchen (Germany)

    2008-07-01

    This article takes a look at how the possibilities of optimising power, heat and cold generation for the German Giesecke and Devrient company were examined and implemented. The company, which produces banknotes and chip-cards, chose the combination of a Combined Heat and Power (CHP) Unit and a two-stage absorber refrigeration system. The company's old system is briefly described and the reasons for replacing it are discussed. The careful dimensioning of the new system and the search for appropriate equipment are described. Intelligent power flows and a cooling system with two different temperature levels are described. Costs saved and emergency power generation are also looked at, as are the complex demands placed on the control of the system. The system's functioning is briefly described.

  18. Comparison of two continuous fungal bioreactors for posttreatment of anaerobically pretreated weak black liquor from kraft pulp mills.

    Science.gov (United States)

    Ortega-Clemente, Alfredo; Marín-Mezo, G; Ponce-Noyola, M T; Montes-Horcasitas, M C; Caffarel-Méndez, S; Barrera-Cortés, Josefina; Poggi-Varaldo, Héctor M

    2007-03-01

    The purpose of this work was to evaluate and compare two continuous systems of posttreatment of anaerobically pretreated weak black liquor (WBL). The first system consisted of a packed bed reactor (PBR) with Trametes versicolor (Tv) immobilized on wood cubes of holm oak (biocubes). The second system was a fluidized bed reactor (FBR) with Lentinus edodes (Le) immobilized on wood cubes of holm oak. The reactors operated for 65 days at a hydraulic retention time (HRT) of 5 days, at 28 degrees C, with continuous aeration. Response variables monitored were conventional and specific, unit, net removal efficiency (eta and eta(sun), respectively) of chemical oxygen demand (COD), color, and ligninoids, and enzymatic activities of manganese peroxidase (MnP), lignin peroxidase (LiP), laccase (Lac) and proteases. The PBR showed an average color eta superior to that of the FBR (52.42 +/- 21.78% and 25.34 +/- 14.38% for PBR and FBR, respectively); removals of COD and ligninoids presented a similar pattern to that of color. Lac activity was significantly larger in PBR than in FBR. Activity of MnP in PBR was higher than that of the FBR (0.004 and 0.002 U MnP/mL, respectively). This difference could be ascribed to the different fungi present in each bioreactor. LiP activity was very low in both reactors. Average value of proteases was almost double in the FBR as compared with PBR (0.472 and 0.209 U Proteases/mL, respectively). During the last 2 weeks of operation, biocubes in the FBR experienced a significant loss of the attached Le biomass, probably by attrition. This and higher protease activity in the FBR could explain the lower pollutant removals achieved in the FBR. Overall, PBR with immobilized Tv showed a better performance than the FBR with Le for the posttreatment of the recalcitrant anaerobic effluent. Extended and sustained pollutant removal (65 days) was achieved in the PBR, although more research is needed to evaluate bioreactor performance at shorter hydraulic retention times.

  19. Maailma maksunduse trendid / Sulev Nõmmann, Olavi Kärsna, Paul Tammert, Lemmi Oro ... [jt.] ; eess.: Vahur Kraft

    Index Scriptorium Estoniae

    2003-01-01

    Maksukoormuse trendid, füüsilise isiku tulu- ja sotsiaalmaksu trendid, äriühingu kasumi maksustamine, omandi- ja isikumaksu trendid, tarbimismaksud, keskkonnaga seotud maksud, kontroll maksurahade kasutamise üle

  20. Temperature and Copper Concentration Effects on the Formation of Graphene-Encapsulated Copper Nanoparticles from Kraft Lignin

    Directory of Open Access Journals (Sweden)

    Weiqi Leng

    2017-06-01

    Full Text Available The effects of temperature and copper catalyst concentration on the formation of graphene-encapsulated copper nanoparticles (GECNs were investigated by means of X-ray diffraction, Fourier transform infrared spectroscopy-attenuated total reflectance, and transmission electron microscopy. Results showed that higher amounts of copper atoms facilitated the growth of more graphene islands and formed smaller size GECNs. A copper catalyst facilitated the decomposition of lignin at the lowest temperature studied (600 °C. Increasing the temperature up to 1000 °C retarded the degradation process, while assisting the reconfiguration of the defective sites of the graphene layers, thus producing higher-quality GECNs.

  1. MINERAL ELEMENTS IN WOODS OF EUCALYPTUS AND BLACK WATTLE AND ITS INFLUENCE IN A BLEACHED KRAFT PULP MILL

    Directory of Open Access Journals (Sweden)

    André Fredo

    2009-09-01

    Full Text Available Effluents are one of the most important problems in a pulp mill regarding to environmental subjects. With the purpose to reduce them, the mills are closing the internal cycles and reducing the water consumption. The wood, as the most significant source of non-process elements to the system, is responsible for some troubles to the industrial process. With the aim of evaluating their intake and to offer some informations for closing the loop, the contents of Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, and Si were analysed in Acacia mearnsii, Eucalyptus dunnii, Eucalyptus globulus globulus, Eucalyptus grandis and Eucalyptus saligna woods. Wood samples were prepared by oven burning and acidic digestion methods, following analysis by ICP (inductively coupled plasm. Using also the results from silvicultural evaluation of trees and stands, they were calculated which elements were carried out from the site in larger amounts (K, Ca, Na, Al, Mn and Si and the species which exported largest amount of these elements (Eucalyptus dunnii and Eucalyptus globulus. The species with lower growth were Eucalyptus globulus and Eucalyptus dunnii, that leads to a bigger elements input and more potential industrial troubles. It was observed a range of 3.8 (Eucalyptus grandis up to 6 (Eucalyptus dunnii kg of analised mineral elements introduced to the process per ton of umbleached pulp produced. The Acacia mearnsii showed the lower level for Fe, Mn and Ni, being useful for oxygen, ozone and peroxide bleaching. The silicon observed in woods was in low concentration although the high values of this element in industrial liquor cycle. This leads to state that there is some contamination with soil when harvesting and handling the wood. Special care must be taken with both high ash and high mineral elements species, such as Eucalyptus dunnii and Eucalyptus globulus.

  2. Trigeneration in waste to energy plants for expanding the efficiency; Kraft-Waerme-Kaelte-Kopplung bei Muellverbrennungsanlagen zur erweiterten Energieeffizienzsteigerung

    Energy Technology Data Exchange (ETDEWEB)

    Reil, Eberhard [Fernwaerme Wien GmbH, Wien (Austria)

    2010-05-15

    An impressive metamorphosis changed Waste to Energy plants from originally environmental risky plants to high sophisticated end of pipe technology sites to finally high efficient Energy production plants. Such described plants are situated in urban places to aware the connections into efficient power grids and district heating networks to provide the base load the whole year round. Nowadays the request for cooling is steady rising and again Waste to energy plants, connected to a district cooling network, takes over an important role for the supply. Such concepts are only marketable, if the required criteria's for efficiency are fulfilled. Such criteria's within Europe are the greenhouse gas emission factor and the primary energy factor. Both proof the efficiency of a system according to sustainability and environmental acceptance. Such criteria's are the result of the EU target to enhance the renewable within the energy supply while a more efficient use of site energy should take place. The Vienna Model was chosen as best practice sample. The district heating network is connected to all Waste to energy plants as well to the gas fired CHP plants in Vienna. The peak demand for the supply is realized by gas fired hot water boilers. In 2006 Fernwaerme Wien started to set up a district cooling network. The base load for the cooling derives from absorption chillers driven by heat from the waste to energy plants. According the EN standard 15316 part 4 and 5, method for calculation of system energy requirements and system efficiencies, the primary energy factor and CO2 factor has been defined for the Vienna model and as a consequence of that also for the waste to energy plant Pfaffenau. The average primary energy factor of the Vienna model calculated for the years 2006 to 2008 is 0,21 for the renewable part. According to the result the savings on primary energy have been 42 % and equates to 6,9 TWh/a. The reduc tion of the greenhouse gas emissions has been even higher. 52 % within the period 2006 to 2008 which is equal to 1,9 Mio t of greenhouse gas equivalents. The focus only on the waste to energy plant Pfaffenau, start up in 2006, shows an impressive results as well. The primary energy factor is theoretically below zero (-0,11) and the greenhouse gas emission factor reaches -15 t/GWh due to the renewable contingent in the waste of roughly 50 %. Out of plausibility the results are set to zero. (orig.)

  3. Novalignin project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stigsson, Lars [KIRAM AB, Saltsjoebaden (Sweden)

    2002-02-01

    The NovaFiber process is a new and sustainable technology for manufacturing of chemical pulp incorporating an efficient route for recovery of energy and pulping chemicals. The process is substantially sulphur chemicals free and this creates a great potential for recovery of sulphur free lignin for internal use as a fuel or export from the mill. The NovaLignin project has been launched to evaluate this potential from a technical and economical perspective. The NovaLignin research and development effort has been partly financed by NUTEK, Energimyndigheten and Mistra. A major feature of the new lignin is the absence of organically bound sulphur compounds in the material increasing the scope of potential uses for the lignin as a precursor for fine chemicals preparation or as a sulphur free biomass based fuel. Two major forest industry laboratories in Scandinavia have conducted the laboratory cooking and lignin extraction work in the present project. The lignin extracted from the NovaFiber process, NovaLignin, has been characterised and evaluated for use in different applications. The consequences of lignin extraction in different mill configurations with a recovery boiler or a black liquor gasification system for chemicals recovery is outlined below. The NovaFiber pulp mill is compared to a reference mill based on conventional kraft pulping on the same wood raw material. The mill capacity is 2000 t/d bleached softwood pulp. The lime kiln is fired with bark and the remaining falling bark is sold, or if there is a deficit, more bark is purchased. Initial laboratory studies conducted at ATO-DLO, the Netherlands, clearly show a great potential for NovaLignin as a functional additive in thermoplastics. NovaFiber and Kraft lignin act as an UV stabiliser for polyethylene at a comparable level as an expensive commercial stabiliser, such as HALS. This means that NovaFiber lignin has a very good price/performance ratio. Experiments show that NovaFiber lignin has good potential

  4. The effect of oxyalkylation and application of polymer dispersions on the thermoformability and extensibility of paper.

    Science.gov (United States)

    Kouko, Jarmo; Setälä, Harri; Tanaka, Atsushi; Khakalo, Alexey; Ropponen, Jarmo; Retulainen, Elias

    2018-04-15

    Wood fiber-based packaging materials, as renewable materials, have growing market potential due to their sustainability. A new breakthrough in cellulose-based packaging requires some improvement in the mechanical properties of paper. Bleached softwood kraft pulp was mechanically treated, in two stages, using high- and low-consistency refining, sequentially. Chemical treatment of pulp using the oxyalkylation method was applied to modify a portion of fiber material, especially the fiber surface, and its compatibility with polymer dispersions including one carbohydrate polymer. The results showed that the compatibility of the cellulosic fibers with some polymers could be improved with oxyalkylation. By adjusting mechanical and chemical treatments, and the thermoforming conditions, the formability of paper was improved, but simultaneously the strength and stiffness decreased. The results suggest that the formability of the paper is not a direct function of the extensibility of the applied polymer, but also depends on the fiber network structure and surface energy. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. TARGETED DISRUPTION OF HYDROXYL CHEMISTRY AND CRYSTALLINITY IN NATURAL FIBERS FOR THE ISOLATION OF CELLULOSE NANO-FIBERS VIA ENZYMATIC TREATMENT

    Directory of Open Access Journals (Sweden)

    Sreekumar Janardhnan

    2011-04-01

    Full Text Available Cellulose is the Earth’s most abundant biopolymer. Exploiting its environmentally friendly attributes such as biodegradability, renewability, and high specific strength properties are limited by our inability to isolate them from the secondary cell wall in an economical manner. Intermolecular and intramolecular hydrogen bonding between the cellulose chains is the major force one needs to overcome in order to isolate the cellulose chain in its microfibrillar form. This paper describes how a hydrogen bond-specific enzyme disrupts the crystallinity of the cellulose, bringing about internal defibrillation within the cell wall. Bleached kraft softwood pulp was treated with a fungus (OS1 isolated from an elm tree infected with Dutch elm disease. FT-IR spectral analysis indicated a significant reduction in the density of intermolecular and intramolecular hydrogen bonding within the fiber. X-ray spectrometry indicated a reduction in the crystallinity. The isolated nano-cellulose fibers also exhibited better mechanical strength compared to those isolated through conventional methods. The structural disorder created in the crystalline region in the plant cell wall by hydrogen bond-specific enzymes is a key step forward in the isolation of cellulose at its microfibrillar level.

  6. Recent Progress in Producing Lignin-Based Carbon Fibers for Functional Applications

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Ryan [GrafTech International Holdings Inc.; Burwell, Deanna [GrafTech International Holdings Inc.; Dai, Xuliang [GrafTech International Holdings Inc.; Naskar, Amit [Oak Ridge National Laboratory; Gallego, Nidia [Oak Ridge National Laboratory; Akato, Kokouvi [Oak Ridge National Laboratory

    2015-10-29

    Lignin, a biopolymer, has been investigated as a renewable and low-cost carbon fiber precursor since the 1960s. Although successful lab-scale production of lignin-based carbon fibers has been reported, there are currently not any commercial producers. This paper will highlight some of the known challenges with converting lignin-based precursors into carbon fiber, and the reported methods for purifying and modifying lignin to improve it as a precursor. Several of the challenges with lignin are related to its diversity in chemical structure and purity, depending on its biomass source (e.g. hardwood, softwood, grasses) and extraction method (e.g. organosolv, kraft). In order to make progress in this field, GrafTech and Oak Ridge National Laboratory are collaborating to develop lignin-based carbon fiber technology and to demonstrate it in functional applications, as part of a cooperative agreement with the DOE Advanced Manufacturing Office. The progress made to date with producing lignin-based carbon fiber for functional applications, as well as developing and qualifying a supply chain and value proposition, are also highlighted.

  7. Research on the suitability of organosolv semi-chemical triticale fibers as reinforcement for recycled HDPE composites

    Directory of Open Access Journals (Sweden)

    Nour-Eddine El Mansouri

    2012-11-01

    Full Text Available The main objective of this research was to study the feasibility of incorporating organosolv semi-chemical triticale fibers as the reinforcing element in recycled high density polyethylene (HDPE. In the first step, triticale fibers were characterized in terms of chemical composition and compared with other biomass species (wheat, rye, softwood, and hardwood. Then, organosolv semi-chemical triticale fibers were prepared by the ethanolamine process. These fibers were characterized in terms of its yield, kappa number, fiber length/diameter ratio, fines, and viscosity; the obtained results were compared with those of eucalypt kraft pulp. In the second step, the prepared fibers were examined as a reinforcing element for recycled HDPE composites. Coupled and non-coupled HDPE composites were prepared and tested for tensile properties. Results showed that with the addition of the coupling agent maleated polyethylene (MAPE, the tensile properties of composites were significantly improved, as compared to non-coupled samples and the plain matrix. Furthermore, the influence of MAPE on the interfacial shear strength (IFSS was studied. The contributions of both fibers and matrix to the composite strength were also studied. This was possible by the use of a numerical iterative method based on the Bowyer-Bader and Kelly-Tyson equations.

  8. Life-Cycle Energy and GHG Emissions for New and Recovered Softwood Framing Lumber and Hardwood Flooring Considering End-of-Life Scenarios

    Science.gov (United States)

    Richard D. Bergman; Robert H. Falk; Hongmei Gu; Thomas R. Napier; Jamie Meil

    2013-01-01

    Within the green building fields is a growing movement to recover and reuse building materials in lieu of demolition and land fill disposal. However, they lack life-cycle data to help quantify environmental impacts. This study quantifies the primary energy and greenhouse gas (GHG) emissions released from the production of wood recovered from an old house and from new...

  9. Comparison of macromolecular interactions in the cell walls of hardwood, softwood and maize by fluorescence and FTIR spectroscopy, differential polarization laser scanning microscopy and X-ray diffraction

    Czech Academy of Sciences Publication Activity Database

    Djikanović, D.; Devecerski, A.; Steinbach, Gabor; Simonović, J.; Matović, B.; Garab, G.; Kalauzi, A.; Radotić, K.

    2016-01-01

    Roč. 50, č. 3 (2016), s. 547-566 ISSN 0043-7719 Institutional support: RVO:61388971 Keywords : IR SPECTROSCOPY * CROSS-LINKING * CELLULOSE Subject RIV: EE - Microbiology, Virology Impact factor: 1.509, year: 2016

  10. Direct analysis by time-of-flight secondary ion mass spectrometry reveals action of bacterial laccase-mediator systems on both hardwood and softwood samples.

    Science.gov (United States)

    Goacher, Robyn E; Braham, Erick J; Michienzi, Courtney L; Flick, Robert M; Yakunin, Alexander F; Master, Emma R

    2017-12-29

    The modification and degradation of lignin play a vital role in carbon cycling as well as production of biofuels and bioproducts. The possibility of using bacterial laccases for the oxidation of lignin offers a route to utilize existing industrial protein expression techniques. However, bacterial laccases are most frequently studied on small model compounds that do not capture the complexity of lignocellulosic materials. This work studied the action of laccases from Bacillus subtilis and Salmonella typhimurium (EC 1.10.3.2) on ground wood samples from yellow birch (Betula alleghaniensis) and red spruce (Picea rubens). The ability of bacterial laccases to modify wood can be facilitated by small molecule mediators. Herein, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), gallic acid and sinapic acid mediators were tested. Direct analysis of the wood samples was achieved by time-of-flight secondary ion mass spectrometry (ToF-SIMS), a surface sensitive mass spectrometry technique that has characteristic peaks for H, G and S lignin. The action of the bacterial laccases on both wood samples was demonstrated and revealed a strong mediator influence. The ABTS mediator led to delignification, evident in an overall increase of polysaccharide peaks in the residual solid, along with equal loss of G and S-lignin peaks. The gallic acid mediator demonstrated minimal laccase activity. Meanwhile, the sinapic acid mediator altered the S/G peak ratio consistent with mediator attaching to the wood solids. The current investigation demonstrates the action of bacterial laccase-mediator systems directly on woody materials, and the potential of using ToF-SIMS to uncover the fundamental and applied role of bacterial enzymes in lignocellulose conversion. © 2017 Scandinavian Plant Physiology Society.

  11. Wood pellets, what else? : Greenhouse gas parity times of European electricity from wood pellets produced in the south-eastern United States using different softwood feedstocks

    NARCIS (Netherlands)

    Hanssen, Steef V.; Duden, Anna S.; Junginger, Martin; Dale, Virginia H.; van der Hilst, Floortje

    Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas (GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are

  12. GLOBAL JOURNAL OF AGRICULTURAL SCIENCES ISSN 1596-2903

    African Journals Online (AJOL)

    Ada Global

    semi-hardwood and softwood) of the stem cuttings of G. latifolia in relation to ... second week after planting even though softwood cuttings started earlier showed the importance of carbohydrate ..... women in the University of Nigeria, Nsukka.

  13. Possible Demands for Eastern Hardwoods Resulting from Harvest Restrictions in the Pacific

    Science.gov (United States)

    Janice K. Wiedenbeck; Philip A. Araman

    1993-01-01

    Efforts to conserve the habitat of the northern spotted owl in the Pacific Northwest have placed softwood timber supplies under a great deal of pressure and driven up the price of softwood lumber. Hardwoods could meet some of the demand for products that have previously been manufactured from softwood species. Hardwood structural lumber may soon become an economically...

  14. SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS HOGGED FUEL BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

    Science.gov (United States)

    Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

  15. Combined heat and power generation with fuel cells in residential buildings in the future energy system; Kraft-Waerme-Kopplung mit Brennstoffzellen in Wohngebaeuden im zukuenftigen Energiesystem

    Energy Technology Data Exchange (ETDEWEB)

    Jungbluth, C.H.

    2007-04-27

    Combined heat and power generation (CHP) is regarded as one of the cornerstones of a future sustainable energy system. The application of this approach can be substantially extended by employing fuel cell technologies in small units for supplying heat to residential buildings. This could create an additional market for combined heat and power generation corresponding to approx. 25% of the final energy demand in Germany today. In parallel, the extensive application of distributed fuel cell systems in residential buildings would have substantial effects on energy infrastructures, primary energy demand, the energy mix and greenhouse gas emissions. It is the aim of the present study to quantify these effects via scenario modelling of energy demand and supply for Germany up to the year 2050. Two scenarios, reference and ecological commitment, are set up, and the application and operation of fuel cell plants in the future stock of residential buildings is simulated by a bottom-up approach. A model of the building stock was developed for this purpose, consisting of 213 types of reference buildings, as well as detailed simulation models of the plant operation modes. The aim was, furthermore, to identify economically and ecologically optimised plant designs and operation modes for fuel cells in residential buildings. Under the assumed conditions of the energy economy, economically optimised plant sizes for typical one- or two-family homes are in the range of a generating capacity of a few hundred watts of electrical power. Plant sizes of 2 to 4.7 kW{sub el} as discussed today are only economically feasible in multifamily dwellings. The abolition of the CHP bonus reduces profitability, especially for larger plants operated by contractors. In future, special strategies for power generation and supply can be an economically useful addition for the heat-oriented operation mode of fuel cells. On the basis of the assumed conditions of the energy economy, a technical potential for heat generation by fuel cells of 60% of the heat demand of residential buildings in Germany can be expected in 2030. In the reference scenario, this value remains stable up to 2050, while in the ecological commitment scenario fuel cells are crowded out of the market by 2050 due to the intensified application of renewable energy technologies. With the market dynamics of fuel cells assumed here, they can cover approx. 10-11% of the heat demand of all residential buildings by 2030. In the reference scenario, this value increases to 25% by 2050. At the same time, the fuel cell stock can supply approx. 10% of total power demand in Germany in 2030, while in the reference scenario the proportion increases to approx. 18% by 2050, which means about 100 TWh per year. Fuel cell application will increase natural gas demand in Germany by 81 TWh by 2030 (reference scenario). The replacement of other fuels will thus reduce CO{sub 2} emissions by approx. 36 million tons. (orig.)

  16. ``Turbo-KWK `99``. Combined-cycle power stations with gas turbines. Technical meeting; Turbo-KWK `99. Kraft-Waerme-Kopplung mit Gasturbinen. Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    This conference report comprises 18 contributions on the technological success of gas turbines in power generation, e.g.: Maximum power generation efficiency of combined cycle systems, flexibility of power generation, reduction of air pollution, hot gas production for drying processes and environment-friendly cold generation in the pharmaceutical and printing industries. The final contribution presents an outlook to the future.

  17. Development of an integrated system for a SOFC for combined heat and power generation; Entwicklung eines integrierten Systems fuer eine SOFC mit Kraft-Waerme-Stoffkopplung

    Energy Technology Data Exchange (ETDEWEB)

    Stichtenoth, J.; Meyer-Pittroff, R.

    2002-06-01

    The feasibility of CO2 removal from the exhaust of a 250 kW{sub e} SOFC module, with recirculation of the liquefied CO2 is discussed for the example of a German brewery (Bayerische Staatsbrauerei Weihenstephan). An electric efficiency of 50% can be achieved provided that the liquefied CO2 is utilized to substitute CO2 liquefaction in another point of the process. The high-temperature waste heat of the 250 kW SOFC is fed into the brewer's copper via feedwater preheating. [German] In dieser Studie werden die Moeglichkeiten einer technischen Rueckgewinnung von CO{sub 2} aus dem Abgasstrom eines SOFC-Moduls mit 250 kW elektrischer Leistung und Rueckfuehrung des verfluessigten CO{sub 2} in den Wertschoepfungsprozess am Beispiel der Bayerischen Staatsbrauerei Weihenstephan untersucht. Unter der Voraussetzung, dass dieses verfluessigte CO{sub 2} als Produkt Verwendung findet und die CO{sub 2}-Verfluessigung an anderer Stelle substituiert, kann der von der SOFC gelieferte Energiebeitrag zur CO{sub 2}-Verfluessigung dem Gesamtsystem gutgeschrieben werden, so dass der elektrische Wirkungsgrad bei 50% bleibt. Die Hochtemperaturabwaerme der 250 kW-SOFC wird ueber eine Speisewasservorwaermung in den Dampfkessel der Brauerei eingekoppelt.

  18. Using Apparent Density of Paper from Hardwood Kraft Pulps to Predict Sheet Properties, based on Unsupervised Classification and Multivariable Regression Techniques

    Directory of Open Access Journals (Sweden)

    Ofélia Anjos

    2015-07-01

    Full Text Available 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.

  19. Uso de antraquinona na deslignificação Kraft como forma de minimizar o impacto ambiental causado pelos compostos de enxofre

    OpenAIRE

    Martins, Sandra Mara

    2012-01-01

    Resumo: A produção de polpa celulósica é de grande importância nas indústrias de celulose e papel e na economia brasileira, uma vez que o Brasil se destaca mundialmente por sua elevada produção e exportação de papel. Dentre as várias operações unitárias que constituem o processo de obtenção de celulose, a mais crítica é com certeza a que envolve as reações químicas no reator, pois é principalmente nessa etapa que se define a qualidade da polpa produzida, assim como pode tornar mais fácil as e...

  20. Combined use of solar heat and cogeneration - a perspective for district heating?; Kombinierter Einsatz von solarer Waerme und Kraft-Waerme-Kopplung - eine Perspektive fuer die Nahwaerme?

    Energy Technology Data Exchange (ETDEWEB)

    Entress, J. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Stuttgart (Germany). Abt. Systemanalyse und Technikbewertung; Steinborn, F. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany). Fachgebiet Systemanalyse

    1998-02-01

    With Cogeneration of Heat and Power (CHP), climate-endangering CO{sub 2}-emissions can be reduced singificantly. The heat produced can be delivered at prices comparable to those of conventionally produced heat. With solar district heating, yet higher CO{sub 2}-savings are possible but at higher cost. Promising is a combination of CHP and solar district heating: The heat storage of the solar system can be used to level out heat demand, leading to smooth CHP operation, while heat generated by CHP can be used to substitute for low irradiation during the winter period. However, calculations together with simulation and optimization indicate that combining CHP and solar district heating is not the optimal solution in all cases. (orig.) [Deutsch] Der Einsatz von Blockheizkraftwerken (BHKW) kann zu einer deutlichen Reduzierung der klimagefaehrdenden CO{sub 2}-Emissionen beitragen. Dabei kann die ausgekoppelte Waerme etwa zum gleichen Preis wie konventionell erzeugte Waerme abgegeben werden. Hoehere CO{sub 2}-Einsparungen lassen sich hingegen mit solarer Nahwaerme erzielen, allerdings zu hoeheren Kosten. Eine Kombination dieser beiden Waermetechniken verspricht Vorteile: Einerseits kann der Waermespeicher des Solarsystems auch zum Ausgleich von Lastspitzen beim Betrieb des BHKW`s genutzt werden. Andererseits kann die waehrend der einstrahlungsarmen Wintermonate fehlende solare Waerme durch das BHKW erzeugt werden. Detaillierte Simulations- und Optimierungsrechnungen zeigen jedoch, dass eine Kombination dieser Waermetechniken nicht immer empfehlenswert ist. (orig.)

  1. How efficient work biomass cogeneration plants? A survey of plant operators; Wie effizient arbeiten Biomasseheiz(kraft)werke? Befragung von Anlagenbetreibern

    Energy Technology Data Exchange (ETDEWEB)

    Meiller, Martin; Jakuttis, Michael [Fraunhofer-Institut fuer Umwelt-, Sicherheits- und Energietechnik UMSICHT, Sulzbach-Rosenberg (Germany); Binder, Samir [Fraunhofer-Institut fuer Umwelt-, Sicherheits- und Energietechnik UMSICHT, Sulzbach-Rosenberg (Germany); Bayerischer Forschungsverbund Foreta, Sulzbach-Rosenberg (Germany)

    2013-03-01

    The use of biomass has increased very much in recent years. Due to the intensive use, the price of biomass fuels such as wood chips has increased substantially. This development bothers mainly biomass cogeneration plants. Many operators suffered considerable financial losses or even had to file for bankruptcy. The topic of efficiency is one of the central and critical success factors for the long-term viability of biomass-fired plants. (orig.)

  2. Waste fatty acid addition to black liquor to decrease tall oil soap solubility and increase skimming efficiency in kraft mills pulping mountain pine beetle-infested wood

    Energy Technology Data Exchange (ETDEWEB)

    Uloth, V.; Guy, E. [FPInnovations, Prince George, BC (Canada). PAPRICAN Div.; Shewchuk, D. [Cariboo Pulp and Paper, Quesnel, BC (Canada); Van Heek, R. [Aker Kvaerner, Vancouver, BC (Canada)

    2009-07-01

    This paper presented the results of tests conducted to determine if the addition of waste fatty acids from vegetable oil processing might decrease tall oil soap solubility in pine-beetle impacted wood from British Columbia (BC). The soap recovery and tall oil production at BC mills has fallen by 30 to 40 percent in recent years due to the pulping of high proportions of grey-stage beetle-impacted wood. Full-scale mill tests were conducted over a 4-day period. The study showed that the addition of tall oil fatty acids or waste fatty acids from vegetable oil processing could decrease tall oil soap solubility and increase the soup skimming efficiency in mills pulping a large percentage of grey stage beetle-infested wood. The addition of fatty acids increased tall oil soap skimming efficiency from 50.2 percent in the baseline tests to 71.8 percent based on the total soap available, and from 76.7 percent in the baseline tests to 87.5 percent based on insoluble soap only. The economic analyses indicated that waste fatty acid addition could be economical when natural gas and oil prices are high. 4 tabs., 9 figs.

  3. Promising energy converters for the next century. Fuel cells for cogeneration systems; Aussichtsreicher Energiewandler fuers naechste Jahrhundert. Brennstoffzelle fuer Kraft-Waerme-Kopplung

    Energy Technology Data Exchange (ETDEWEB)

    Hilscher, G

    1996-02-16

    First there is a report on experience with phosphoric acid fuel cell plants (PAFC), which the operators used in a 200 kW plant of Onsi (HEAG, Ruhrgas AG, Thyssengas AG) and a 79 kW plant of Kinetics Technology (Solar-Wasserstoff Bayern GmbH). After this, the present state of development of oxide ceramic high temperature fuel cells (SOFC) and polymer electrolyte diaphragm fuel cells (PEMFC) is briefly described. (MM) [Deutsch] Zuerst wird ueber Erfahrungen mit Phosphorsaeure-Brennstoffzellen-Anlagen (PAFC) berichtet, die die Betreiber einer 200 kW-Anlage von Onsi (HEAG, Ruhrgas AG, Thyssengas AG) und einer 79 kW-Anlage von Kinetics Technology (Solar-Wasserstoff-Bayern GmbH) hatten. Danach wird kurz der derzeitige Stand der Entwicklung bei den oxidkeramischen Hochtemperaturbrennstoffzellen (SOFC) und Polymer-Elektrolyt-Membran-Brennstoffzellen (PEMFC) wiedergegeben. (MM)

  4. Extraction of hemicellulose from South African eucalyptus grandis using weak white liquor activation technology and its impact on kraft pulping efficiency

    CSIR Research Space (South Africa)

    Johakimu, Jonas K

    2017-09-01

    Full Text Available This work summarises the findings of our research on the activation of woodchips using weak white liquor as an alternative mill self-generated alkaline solvent. The ultimate goal was to gain a better understanding on: the effectiveness of the weak...

  5. Combined heat and power generation. A guide for towns and communities, trade and industry; Kraft-Waerme-Kopplung. Ein Leitfaden fuer Staedte und Gemeinden, Gewerbe und Industrie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The brochure describes the cogeneration technology and explains its advantages. Fields of application and potential users are characterized. The technical and economic prospects are outlined, as well as the cost-profit ratios and the chances and problems of this technology. [German] Die vorliegende Broschuere will dem Leser einen Ueberblick ueber die Thematik der KWK geben und einen Beitrag zu ihrer Foerderung leisten. Die Broschuere will: - Ueber KWK informieren, - die Vorteile der KWK erlaeutern, - die Anwendungsfelder und die moeglichen Anwender charakterisieren, - die technisch-wirtschaftlichen Moeglichkeiten fuer die Nutzung der kW aufzeigen, - die Kosten-Nutzen-Relationen und die wirtschaftlichen Chancen und Probleme der KWK verdeutlichen. (orig.)

  6. Ultrafiltration and valorisation of lignin in black liquor from South African Kraft mills: A focus on dead-end stirred cell filtration

    CSIR Research Space (South Africa)

    Kekana, PT

    2014-07-01

    Full Text Available stream_source_info Kekana_2014_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 1098 Content-Encoding ISO-8859-1 stream_name Kekana_2014_ABSTRACT.pdf.txt Content-Type text/plain; charset=ISO-8859-1 2014... International Conference on Chemical Thermodynamics and South African Institution of Chemical Engineering Conference, Durban International Convention Centre in Durban, South Africa, 27 July - 01 August 2014 Ultrafiltration and valorisation of lignin...

  7. Reactivity of syringyl and guaiacyl lignin units and delignification kinetics in the kraft pulping of Eucalyptus globulus wood using Py-GC-MS/FID.

    Science.gov (United States)

    Lourenço, Ana; Gominho, Jorge; Marques, António Velez; Pereira, Helena

    2012-11-01

    Eucalyptus globulus sapwood and heartwood showed no differences in lignin content (23.0% vs. 23.7%) and composition: syringyl-lignin (17.9% vs. 18.0%) and guaiacyl-lignin (4.8% vs. 5.2%). Delignification kinetics of S- and G-units in heartwood and sapwood was investigated by Py-GC-MS/FID at 130, 150 and 170°C and modeled as double first-order reactions. Reactivity differences between S and G-units were small during the main pulping phase and the higher reactivity of S over G units was better expressed in the later pulping stage. The residual lignin composition in pulps was different from wood or from samples in the initial delignification stages, with more G and H-units. S/G ratio ranged from 3 to 4.5 when pulp residual lignin was higher than 10%, decreasing rapidly to less than 1. The S/H was initially around 20 (until 15% residual lignin), decreasing to 4 when residual lignin was about 3%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Chemie für den Maschinenbau. Bd. 2: Organische Chemie für Kraft- und Schmierstoffe, Polymerchemie für Polymerwerkstoffe

    OpenAIRE

    Gerthsen, Tarsilla

    2008-01-01

    Dieses Buch beinhaltet zunächst eine kurze Einführung in die Organische Chemie. Organische Grundkenntnisse sind die Voraussetzung, um nicht nur Kraftstoffe und Schmierstoffe zu verstehen, sondern im Besonderen die Polymerchemie für Polymerwerkstoffe. Die Vorlesung "Polymerwerkstoffe" wird im Maschinenbaustudium in einem höheren Semester angeboten. Allgemeine chemische Grundkenntnisse für Chemie im Nebenfach findet man im Buch 1 "Chemie für Maschinenbau - Anorganische Chemie f...

  9. The current suggestions on amending the new Act on Combined Heat and Power Generation; Die aktuellen Vorschlaege zur Novellierung der Kraft-Waerme-Kopplungsgesetzes

    Energy Technology Data Exchange (ETDEWEB)

    Lamfried, D. [Lueneburg Univ. (Germany)

    2007-10-15

    In the contribution under consideration the author reports on current suggestions on amending the new Act on Combined Heat and Power Generation (KWKG). In particular, the design by the Federal Ministry of Economics and Technology (BMWi, Berlin, Federal Republic of Germany) is interesting. The vote on the direct financial voting according to KWKG with the indirect instrument of emission trade underlines the denotation of the emission trade. Nevertheless, the design of the BMWi cannot be considered as a conclusive concept of the financial support. The emission trade does not offer sufficient financial terms of reference with respect to the extension of the KWKG. It has no control effects. The current version of the BMWi does not go beyond the valid rights decisively. The application of the 10 MW threshold results into an enormous retrogressive step in the financial support of the modernization of stock plants. There exists some reasons according to a continuing legal procedure. The expansion of the utilization of the combined heat and power generation in the production of electricity in the Federal Republic of Germany has a great potential in the reduction of emission of CO{sub 2}.

  10. FAWA - Field-analysis of Heat-pump Installations - Proceedings; Tagungsband zur 11. Tagung des Forschungsprogramms Umgebungswaerme, Waerme-Kraft-Kopplung, Kaelte des Bundesamts fuer Energie (BFE)

    Energy Technology Data Exchange (ETDEWEB)

    Rognon, F.

    2004-07-01

    These proceedings of the 11th conference organised by the Swiss Federal Office of Energy's Research Programme on Ambient Heat, Combined Heat and Power and Refrigeration present 6 papers on heat-pump topics. These include two papers concerning the results obtained from the FAWA project - a unique study of over 230 heat pump installations in operation in the field that was started in 1996 to assess the success of Swiss heat-pump promotion activities. The activities of the Swiss Heat-pump Testing Centre are dealt with and the potential for cost reductions through the optimal choice of system - done according to the motto 'small and simple is beautiful' - is reviewed. A further contribution deals with the question of the heat-pump customer being the 'king'. The role of installers and fitters acting as the instances who choose which system is to be used is looked at in a further contribution. A list of useful addresses completes the proceedings.

  11. Deslignificación de pasta kraft de Pinus radiata con una levadura genéticamente modificada para producir lacasa

    OpenAIRE

    Arana-Cuenca, A.; Yagüe, Susana; Fermiñán, Encarnación

    2010-01-01

    Una posible aplicación biotecnológica de las lacasas fúngicas es el blanqueo de pasta de papel mediante la degradación de la lignina en la pasta cruda. Para ello es necesaria su producción a bajo coste y a concentraciones superiores a las secretadas por los hongos de forma natural. La expresión heteróloga en levaduras es una alternativa para su producción a mayor escala. En el presente trabajo se ha realizado la expresión heteróloga del gen cglcc1, responsable de la producción de lacasa en el...

  12. Integración del proceso Kraft de obtención de pasta de celulosa en el esquema de una biorrefinería

    OpenAIRE

    Martín Sampedro, Raquel

    2012-01-01

    El concepto de biorrefinería se basa en el uso eficiente de la biomasa lignocelulósica como materia prima en la producción integrada de combustibles, energía y productos químicos. Basándonos en este concepto, una fábrica de pastas celulósicas podría convertirse en una biorrefinería en la que, además de pasta, se obtendrían otros productos como etanol, bio-polímeros y otros compuestos químicos. Para conseguir dicho objetivo, se llevó a cabo un tratamiento de explosión por vapor previo al past...

  13. An approach to industrial application: influence of black liquor and pH on xylanase efficiency in bleaching of eucalyptus kraft pulp

    OpenAIRE

    Fillat Latorre, Úrsula; Roncero Vivero, María Blanca; Bassa, Alexandre; Sacón, Vera Maria

    2010-01-01

    To obtain a more realistic appraisal of the potential efficiency of xylanases in the industrial bleaching, the influence of pH and the presence of black liquor (measured as COD) on the bleaching efficiency of two commercial xylanases was studied at high temperature. These pH’s, CODs, and temperatures are close to those used in the storage tower of the B fiber line in Jacareı´ unit of Fibria (Brazil). The pulp samples obtained after each bleaching stage were analyzed for kappa number, brigh...

  14. Vergleichende Kraft-Dehnungs- und Dauerlastversuche mit kieferorthopädischen Gummizügen und pseudoelastischen Ni-Ti-Federn

    OpenAIRE

    Buch, Stefan

    2003-01-01

    Bei einer Behandlung mit festsitzenden Apparaturen stehen für Zahnverschiebungen in mesio-distaler Richtung und zur Okklusionseinstellung seit 1993 als Alternative zu Gummiringen aus Latex Zugfedern aus der Nickel-Titan-Legierung Sentalloy zur Verfügung. Die vorliegende Untersuchung zeigt die materialtechnischen Besonderheiten der beiden Werkstoffe auf und beschreibt die Vor- und Nachteile in der klinischen Anwendung der Gummizüge und der Federn. Es wurden Gummizüge aus Latex von Ormco Dental...

  15. Green Heat and Power. Eco-effective Energy Solutions in the 21st Century; Groenn kraft og varme. Miljoeeffektive energiloesninger i det 21. aarhundre

    Energy Technology Data Exchange (ETDEWEB)

    Palm, T.; Buch, C.; Kruse, B; Sauar, E.

    1999-06-01

    Norway has emerged as a major producer of oil, gas, and hydropower during the lifetimes of the authors of this report. Our accumulated experience in working on environmental conservation spans approximately 50 years, with our main area of concentration being energy and the environment. Although river systems have been harnessed into pipes and many oil fields have been developed, on the threshold of a new century we feel confident that the majority would agree that our future energy needs cannot be based and sustained on the exploitation of the natural environment. This report outlines how Norway can reposition itself to become an important energy supplier that can help solve environmental problems instead of create them. It is also a guide to what we think is important to know about energy and the challenges facing the environment. It is all too easy to become swamped by information, which is why we have elected to focus firmly on essentials. We not only look at the solutions of the past, we look into what the future may bring. New thinking and approaches to the problems that are as yet little known are outlined in detail. We seek to present solutions developed from a more integrated ''big-picture'' perspective. Our target audience is people with a general interest in the subject, individuals who work with these kinds of challenges on a day-to-day basis, politicians and other decision-makers, and people who are actively engaged in research and development. This report represents a stark contrast to the report published by the government-appointed energy co mission, a commission which was unable to demonstrate how Norway could both increase energy production and decrease energy consumption, while simultaneously reducing greenhouse-gas emissions in compliance with our international commitments. The report documents that up until the year 2020, Norway can free up one sixth of the electricity produced, reduce CO2 emissions by over 50%, produce 50 TWh of renewable energy, and export large amounts of ''clean '' fossil fuels such as hydrogen and electricity. We have only proposed measures up until 2010, partly because the world will have changed by that time, and because the best means of predicting the future is to be part of creating it.

  16. Interactions between Cellulolytic Enzymes with Native, Autohydrolysis, and Technical Lignins and the Effect of a Polysorbate Amphiphile in Reducing Nonproductive Binding.

    Science.gov (United States)

    Fritz, Consuelo; Ferrer, Ana; Salas, Carlos; Jameel, Hasan; Rojas, Orlando J

    2015-12-14

    Understanding enzyme-substrate interactions is critical in designing strategies for bioconversion of lignocellulosic biomass. In this study we monitored molecular events, in situ and in real time, including the adsorption and desorption of cellulolytic enzymes on lignins and cellulose, by using quartz crystal microgravimetry and surface plasmon resonance. The effect of a nonionic surface active molecule was also elucidated. Three lignin substrates relevant to the sugar platform in biorefinery efforts were considered, namely, hardwood autohydrolysis cellulolytic (HWAH), hardwood native cellulolytic (MPCEL), and nonwood native cellulolytic (WSCEL) lignin. In addition, Kraft lignins derived from softwoods (SWK) and hardwoods (HWK) were used as references. The results indicated a high affinity between the lignins with both, monocomponent and multicomponent enzymes. More importantly, the addition of nonionic surfactants at concentrations above their critical micelle concentration reduced remarkably (by over 90%) the nonproductive interactions between the cellulolytic enzymes and the lignins. This effect was hypothesized to be a consequence of the balance of hydrophobic and hydrogen bonding interactions. Moreover, the reduction of surface roughness and increased wettability of lignin surfaces upon surfactant treatment contributed to a lower affinity with the enzymes. Conformational changes of cellulases were observed upon their adsorption on lignin carrying preadsorbed surfactant. Weak electrostatic interactions were determined in aqueous media at pH between 4.8 and 5.5 for the native cellulolytic lignins (MPCEL and WSCEL), whereby a ∼20% reduction in the enzyme affinity was observed. This was mainly explained by electrostatic interactions (osmotic pressure effects) between charged lignins and cellulases. Noteworthy, adsorption of nonionic surfactants onto cellulose, in the form cellulose nanofibrils, did not affect its hydrolytic conversion. Overall, our results

  17. Electron beam processing technology for modification of different types of cellulose pulps for production of derivatives

    International Nuclear Information System (INIS)

    Iller, E.; Kukielka, A.; Mikolajczyk, W.; Starostka, P.; Stupinska, H.

    2002-01-01

    Institute of Nuclear Chemistry and Technology, Pulp and Paper Research Institute and Institute of Chemical Fibers carry out a joint research project in order to develop the radiation methods modification of cellulose pulps for production of cellulose derivatives such as carbamate (CC), carboxymethyl cellulose (CMC) and methylcellulose (MC). Three different types of textile pulps: Alicell (A); Borregaard (B), Ketchikan (K) and Kraft softwood (PSS) and hardwood (PSB) pulps have been irradiated with 10 MeV electron beam from LAE 13/9 linear accelerator with doses of 5, 10, 15, 20, 25 and 50 kGy. After electron beam treatment the samples of cellulose pulps have been examined by using of structural and physico-chemical methods. Electron paramagnetic resonance spectroscopy (EPR), gel permeation chromatography (GPC) and infrared spectroscopy (IRS) were applied for determination of structural changes in irradiated cellulose pulps. By means of analytical methods, such parameters as: viscosity, average degree of polymerization (DP) and α-cellulose contents were evaluated. Based on EPR and GPC investigations the relationship between concentrations of free radicals and decreasing polymerization degrees in electron beam treatment pulps has been confirmed. The carboxymethylcellulose, methylcellulose and cellulose carbamate were prepared using the raw material of radiation modified pulps. Positive results of investigations will allow for determination of optimum conditions for electron beam modification of selected cellulose paper and textile pulps. Such procedure leads to limit the amounts of chemical activators used in methods for preparation cellulose derivatives. The proposed electron beam technology is new approaches in technical solution and economic of process of cellulose derivatives preparation. (author)

  18. African Journal of Biotechnology - Vol 11, No 22 (2012)

    African Journals Online (AJOL)

    In vitro regeneration of selected commercial Tanzanian open pollinated maize varieties · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT ... Biobleaching of wheat straw-rich-soda pulp by the application of alkalophilic and thermophilic mannanase from Streptomyces sp. PG-08-3 · EMAIL FREE ...

  19. Optimizing Bacillus circulans Xue-113168 for biofertilizer production ...

    African Journals Online (AJOL)

    In this study, Bacillus circulans Xue-113168 biofertilizer was produced through solid state fermentation processes using food waste and feldspar. Results confirmed that solid state fermentation has considerable advantages compared to complex process (solid-state and bio-bleach). The control of pH, temperature, and ...

  20. Determination of the potential for utilising combined heat and power and of the target reduction of CO{sub 2} emissions, inclusive of cost analysis (increased use of combined heat and power); Ermittlung der Potenziale fuer die Anwendung der Kraft-Waerme-Kopplung und der erzielbaren Minderung der CO{sub 2}-Emissionen einschliesslich Bewertung der Kosten (Verstaerkte Nutzung der Kraft-Waerme-Kopplung)

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Manfred; Ziesing, Hans-Joachim [Deutsches Inst. fuer Wirtschaftsforschung, Berlin (Germany); Matthes, Felix Christian; Harthan, Ralph [Oeko Institut e.V., Berlin (Germany); Menzler, Gerald [VIK Verband der Industriellen Energie- und Kraftwirtschaft e.V., Essen (Germany)

    2007-07-15

    The report provides a statistical overview of CHP utilisation up to now in Germany, analyses the general economic and political conditions with a view to evaluating the competitiveness of CHP, discusses the effectiveness of the German CHP Act with respect to its contribution to meeting emissions-related goals, analyses the cost-effectiveness of investments in different types of new CHP installations, addresses mid- and longer term potential as well as impediments to the utilisation of CHP installations, presents model simulations of how CHP is expected to develop in the context of economic conditions subject to various general political conditions and makes recommendations with an eye to additional requirements and opportunities to support CHP, against the background of the findings of the analysis. (orig.)

  1. Monitoring of the cogeneration agreement from 19th December 2003 for the partition combined heat and power. Reporting period 2010 (Fourth and last report); Monitoring der Kraft-Waerme-Kopplungs-Vereinbarung vom 19. Dezember 2003 fuer den Teilbereich Kraft-Waerme-Kopplung. Berichtszeitraum 2010 (Vierter und letzter Bericht)

    Energy Technology Data Exchange (ETDEWEB)

    Gores, Sabine; Harthan, Ralph O.

    2012-06-04

    Beside the obligation to implement the agreed measures, also the attendance of the 'Agreement between the Government of the Federal Republic of Germany and the German economy on the climate precaution, on the reduction of the CO{sub 2} emissions and on the promotion of the cogeneration in supplement to the climate agreement from 9th November, 2000' by a continuous was initiated. The Rheinisch-Westfaelisches Institut fuer Wirtschaftsforschung (Essen, Bundesrepublik Deutschland) was commissioned with the monitoring of the cogeneration agreement. The monitoring report under consideration is based on the monitoring reports and the relevant official statistics as well as data for the power generation from renewable energy sources.

  2. 75 FR 35792 - Agency Information Collection Activities: Proposed Collection; Comment Request; Information...

    Science.gov (United States)

    2010-06-23

    ... production process units include operations such as pulping, bleaching, chemical recovery and papermaking. Different pulping processes are used, including chemical processes (kraft, soda, sulfite and semi-chemical... chemical pulp mills (kraft, sulfite, semi-chemical and soda wood pulping processes). For existing kraft and...

  3. Advanced Recombinant Manganese Peroxidase for Biosynthesis of Lignin Bioproducts, Phase I Final Report, STTR Grant #: DE-SC0007503.

    Energy Technology Data Exchange (ETDEWEB)

    Beatty, Christopher; Kitner, Joshua; Lajoie, Curtis; McClain, Sean; Potochnik, Steve

    2012-12-13

    The core purpose of this Phase I STTR was to evaluate the feasibility of a new method of producing a recombinant version of manganese peroxidase (MnP) enzyme. MnP is a potentially valuable enzyme for producing high value lignin products and also for industrial de-coloring operations such as biobleaching of pulp and color removal from textile dye effluents. This lignin-modifying enzyme is produced in small amounts by the native host, a white rot fungus. Previous work by Oregon State University developed a secreted recombinant version of the enzyme in the yeast Pichia pastoris. Unfortunately, the expression is barely moderate and the enzyme is heavily glycosylated, which inhibits purification. In this work, the gene for the enzyme is given a tag which targets production of the enzyme to the peroxisome. This is a promising approach since this location is also where heme and hydrogen peroxide are sequestered, which are both necessary cofactors for MnP. More than ten recombinant strains were constructed, verified, and expressed in the Pichia system. Constitutive (GAP) and methanol-induced promoters (AOX) were tried for peroxisomal targeted, cytosolic, and secreted versions of MnP. Only the secreted strains showed activity. The amount of expression was not significantly changed. The degree of glycosylation was lessened using the AOX (methanol) promotoer, but the resulting enzyme was still not able to be purified using immobilized metal affinity chromatography. Additional work beyond the scope of the defined Phase I project was undertaken to construct, verify, and express Pichia strains that mutated the MnP glycosylation sites to inhibit this process. These strains did not show significant activity. The cause is not known, but it is possible that these sites are important to the structure of the enzyme. Also beyond the scope proposed for our Phase I STTR, the team collaborated with AbSci, a startup with a new E. coli based expression system focused on the production of

  4. Reactivity of lignin with different composition of aromatic syringyl/guaiacyl structures and erythro/threo side chain structures in β-O-4 type during alkaline delignification: as a basis for the different degradability of hardwood and softwood lignin.

    Science.gov (United States)

    Shimizu, Satoko; Yokoyama, Tomoya; Akiyama, Takuya; Matsumoto, Yuji

    2012-07-04

    The reactivity of lignin during alkaline delignification was quantitatively investigated focusing on the effect of the structural differences between syringyl and guaiacyl aromatic nuclei and between erythro and threo in the side chain of β-O-4 type lignin substructure on the β-O-4 bond cleavage rate. It was known that the ratio of this reaction rate of the erythro to threo isomers of the dimeric β-O-4 type lignin model compound with two guaiacyl aromatic nuclei was ca. 4. However, the presence of a syringyl nucleus strongly influenced the rate, and the ratio of the syringyl type analogue was in the range between 2.7 and 8.0 depending on the reaction temperature. The effect of syringyl nucleus on the enhancement of the reaction rate appeared to be greater when the syringyl nucleus consists of the cleaving ether bond rather than being a member of the carbon framework.

  5. NATURAL PRODUCTS AS PRESERVATIVES FOR FAST GROWTH WOODS - A REVIEW

    Directory of Open Access Journals (Sweden)

    Ricardo Marques Barreiros

    2011-11-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Wood is a universal material, economic, historic and sustainable. The paucity of species resistant to biological degradation forced man to use other less durable, especially fast growing, from reforestation, as some species of Eucalyptus and Pinus. These species have moderate or no resistance to wood decay organisms need special treatment and preservatives. The products currently used preservatives are highly toxic and are potential environmental hazards and human health. Thus, there is a growing need to develop effective chemicals, non-toxic to humans and the environment. The direction of research has aimed to develop environmentally friendly products and economic viability, and an alternative is the use of Crude Tall Oil (CTO, which is a waste processing coniferous softwood pulp for the production of kraft paper. The tall oil as a protective agent, has been considered a promising method for significantly reducing the capillary water absorption of sapwood, thereby removing one of the factors that favor the wood being attacked by fungi and insects: water, oxygen and nutrients. Research shows that the tall oil can be used neat, either fresh or distilled, or in combination with biocides.A madeira é um material universal, econ

  6. Energy Nation Norway. Development and renewal in a new environmental and geopolitical era; KonKraft rapport 1; Energinasjonen Norge. Videreutvikling og fornyelse i en ny miljoe- og geopolitisk aera

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    'Energy Nation Norway' looks at Norway as an energy nation from both a national and an international perspective. Its purpose is to provide a basis for political and industrial decisions relating to the petroleum industry. The report is particular concerned with the petroleum sector, besides considering the Norwegian energy cluster from a broader perspective. The energy cluster has been and will continue to be a crucial vehicle for economic growth and the development of wealth in Norway. These are the report's main conclusions: The petroleum industry has played a significant part in Norway's economic development, the side-effects of which have benefited the country's entire population. The world's economic growth and wealth development require energy. In the next few decades oil and gas will continue to form a large part of the world's energy consumption. Norway has great opportunities and competitive advantages over other countries as an exporter of CO{sub 2}-effective energy and expertise. A strong petroleum industry is the best foundation for the development of a many-sided energy cluster with greater emphasis on clean renewable energy in the years up to 2030. Further development of the energy cluster will necessitate access to new petroleum resources, utilising the potential of Norway's hydroelectric power, and targeted investment in wind-power. The vision for Energy Nation Norway in 2030 is a strategic choice which will ensure the development of strong, balanced economic growth while at the same time contributing towards dealing with the challenge of climate change. (Author)

  7. Biomass utilisation for combined heat and power generation: Status and perspectives for rural regions. Guelzow expert discussions; Energetische Nutzung von Biomasse mit Kraft-Waerme-Kopplung: Stand der Technik und Perspektiven fuer den laendlichen Raum. Guelzower Fachgespraeche

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Biomass has a high potential but biomass utilisation technologies have not yet reached sufficient maturity for a general breakthrough on the market. Political boundary conditions alone are not sufficient if technical conversion processes are neglected. For the time being, the potential of biomass can not be utilised.

  8. A simple free-piston Sterling engine for combined heat and power generation (CHP) in the residential sector; Einfacher Stirling-Freikolben-Motor fuer die Kraft-Waerme-Kopplung (KWK) im Wohnbereich

    Energy Technology Data Exchange (ETDEWEB)

    Budliger, J.P.

    2001-07-01

    A completely static resonance tube is used in the Stirling cycle, as a substitute for a displacer piston. The Sterling system described works with only one, elastically suspended piston. The simple, cost-effective and maintenance-free basic design concept is explained in full detail, as well as some possible design types of resonance tube-charged, one-piston Stirling systems and their major advantages and performance characterisitcs. (orig./CB) [German] Anstelle eines Schwingkolbens kann auch ein voellig statisches Resonanzrohr eingesetzt werden: das resultierende Stirling-System umfasst nur noch einen einzigen, elastisch aufgehaengten Kolben. Dieses einfache, kostenguenstige und unterhaltsfreie Konzept stellt eine erwartungsvolle Loesung fuer dezentrale KWK-Anlagen dar. Im Vortrag werden einige moegliche Auslegungen solcher, mit Resonanzrohren aufgeladenen 1-Kolben-Stirling-Aggregate diskutiert, ihre wesentlichsten Eigenschaften und Leistungscharakteristiken beschrieben. (orig./CB)

  9. Swiss energy research program on heat-pumps, combined heat and power and refrigeration for 2008-2011; Energieforschungsprogramm. Waermepumpen, Waerme-Kraft-Kopplung, Kaelte fuer die Jahre 2008-2011

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, T. [Hochschule fuer Technik HSR, Rapperswil (Switzerland); Eckmanns, A. [Swiss Federal Office of Energy (OFEN), Berne (Switzerland)

    2009-07-15

    This report published by the Swiss Federal Office of Energy (SFOE) takes a look at the research programme on heat-pumps, combined heat and power and refrigeration for the years 2008 - 2011. Work proposed for the years 2008 - 2011 involves the following topics: Improvement of components and the thermodynamic cycles of heat pumps and refrigeration plants as well as the improvements in the efficiency of cogeneration plants and the reduction of emission of pollutants. Also, the overall optimisation of total systems is to be examined. Highly-efficient systems for sanitary hot water production are to be looked at, as are miniaturisation and new solutions for the installation of heating and cooling systems with heat pumps. Also the development of environmental-friendly working fluids for heat pumps and refrigeration plants is planned. Pilot and demonstration projects are also to be supported in all areas.

  10. Micro gas turbines: An advanced technology for cogeneration in small- and medium-sized companies; Mikro-Gasturbinen: Eine neue Technologie zur Kraft-Waerme-Kopplung in kleinen und mittleren Unternehmen?

    Energy Technology Data Exchange (ETDEWEB)

    Bouvy, C.; Kuperjans, I. [Lehrstuhl fuer Technische Thermodynamik, RWTH Aachen (Germany)

    2004-07-01

    Micro gas turbines are a new technology for cogeneration with capacities of less than 300 kW{sub el}. Owing to the high heat level of up to 650 degrees centigrade, this is a promising technology for small and medium-sized industrial organisations who need process heat and have a low electric base load power consumption. A potential is viewed especially in process steam production and in direct drying. However, as the economic efficiency depends on the process boundary conditions, the project comprised the development of calculation tables to support the decision finding process. (orig.)

  11. Power, heat and cooling production for a group of buildings (CHCP); Integrerade loesningar foer produktion av kraft, vaerme och kyla (CHCP) i grupper av byggnader med el-, vaerme- och kylbehov

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Corfitz [Svenskt Gastekniskt Center AB, Malmoe (Sweden); Bjurstroem, Henrik; Cronholm, Lars-Aake; Forsberg, Maya [AaF-Energi och Miljoe AB, Stockholm (Sweden)

    2005-04-01

    Small-scale production and distribution of power, heat and cooling (CHCP) for a group of buildings is described in this report on a general level. Possible system solutions are identified and a summary of the state-of-the-art is provided. Costs have been compared for different system solutions using a fictitious group of buildings in a case study. CHCP (Combined Heat, Cooling and Power) is an acronym used for a compact cogeneration unit (CHP) that also provides cooling, where cooling may be produced using an absorption cooling machine. The advantage of heat-driven cooling process combined with a cogeneration unit offers is an increase of the annual number of hours during which the cogeneration is operated. This should lead to an increased competitiveness for small-scale cogeneration also in Sweden, which should become even better if the price for electricity continues to increase. Systems with cogeneration and cooling are often associated with the concept of 'distributed generation' of electricity and with units in single buildings such as hotels, hospitals, offices, shopping centers etc. They could also be considered for groups of buildings connected to a small distribution network for district heating, and district cooling. Both steam and hot water are possible energy carriers. The focus of the study was small-scale cogeneration units in the range 0,1 to 2 MW{sub e} with natural gas as fuel. For the sake of the analysis of profitability and of investment, a fictitious area has been defined with four buildings: two hotels, an office and a shopping centre. The maximum total heat and cooling loads of this area are 8 MW heat and 3.5 MW cooling. The alternatives to heat-only boilers and electric chillers in each building studied were based on piping networks. The results from the calculations show that local production of electric power, heat and cooling is possible in buildings and areas with large energy consumption. With prices and assumptions as in the basic case, the payback period for a network bound system with centralised production of district heating and district cooling is about 10 years. Heat and cooling are produced with a CHP unit common to all four buildings and a common electric chiller. Using an absorption chiller is not economically interesting. Placing a CHP unit and an electric chiller in each building in the area considered yields a payback period of about 8 years, which is somewhat shorter. As for a system with a common CHP, absorption chillers are not economically attractive. Systems where heat is distributed as steam or hot water to local cooling units are not economically interesting because investments in the absorption machines are too large.

  12. Diesel engine cogeneration plants in the context of integration of renewable energy sources in power supply; Dieselmotor-Kraft-Waerme-Kopplungsanlagen im Kontext der Integration Erneuerbarer Energien in die Energieversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Sievers, John

    2010-10-29

    The aim of this thesis is to investigate and assess future options, potentials, strengths and weaknesses of cogeneration of heat and power. This is carried out against the background of global climate change and the integration of an increasing share of fluctuating renewable energies in power generation considering the necessity of guaranteeing a reliable, efficient, sustainable and cost effective power supply. It is assumed that the transition process to an entirely renewable energy-based electricity generation in Germany will considerably depend on the integration of wind energy because of its economic competitiveness, environmental friendliness and potential. However, power generation using wind energy fluctuates quite considerably. Diesel motors are here investigated as a decentralized integration instrument. Thanks to their great flexibility, high efficiency and relatively low nominal capacity, they perfectly meet the requirements for the simultaneous decentralized use of heat. Boundary conditions of Diesel motor combined heat and power plants (CHP) are analyzed and described in this work, different models for wind energy integration are elaborated, and these models are used for several variations to simulate the balance of wind energy by cogeneration. In this context, environmental impacts are discussed. Common assessment methods on environmental impacts of CHP distort the results. The so-called output method is developed and described, by which the final assessment of environmental impacts is not implicitly mixed - as is commonly the case - with the calculation of environmental impacts. This output method is used to compare CHP generation with other energy conversion processes within the context of power generation including insulation of buildings, the use of different fuels and different applications for cogeneration. This work clearly demonstrates that while bio fuel resources can be optimally used for power generation, cogenerated electricity could also be used optimally for mobility. The main assessment criteria for this are global warming potential, cumulated energy demand and exergy generation. Furthermore it also investigates potential sources from where the necessary bio energy for Diesel motors could be obtained. It is evident that the agricultural area available in Germany will only enable the production of a small part of the bio energy needed for the German power supply. An interesting option would be to make use of biogas on a larger scale and to import vegetable oils from outside Europe. This should mainly be carried out using degraded land, which would require an agricultural area in the range of 6 to 12 Mio. ha. Final results show that using renewable fuels, and after the integration of wind power, a full balance of the residual load by cogeneration, is reasonable and feasible. Such a wind-cogeneration DSM system should be supplemented by a stronger UCTE electricity grid and by the integration of hydro power plants for balancing power, which will enable the large-scale exchange of renewable energies within Europe and the neighboring regions.

  13. Combined heat, cold and power generation with cold water storage plants. State of the art and development; Kraft-Waerme-Kaelte-Kopplung mit Kaltwasserspeichern. Stand und Entwicklung der Technologie

    Energy Technology Data Exchange (ETDEWEB)

    Urbaneck, Thorsten; Platzer, Bernd [Technische Univ. Chemnitz (Germany). Professur Technische Thermodynamik; Uhlig, Ulf; Goeschel, Thomas [Eins Energie in Sachsen GmbH und Co. KG, Chemnitz (Germany). Betrieb Rohrnetze

    2013-02-18

    District cooling systems with combined heat, cold and power generation may be an alternative for the refrigeration supply with medium-sized decentralized compression refrigerating machines or for the wide-spread application of split devices. The implementation of discontinuously available renewable energy sources can be much better transposed by means of such systems.

  14. Gluing of Eastern Hardwoods: A Review

    Science.gov (United States)

    Terry Sellers; James R. McSween; William T. Nearn

    1988-01-01

    Over a period of years, inrreasing demand for softwoods in the Eastern United States has led to an increase in the growth of hardwoods on cut-over softwood sites. Unfortunately these hardwood trees are often of a size and shape unsuitable for the production of high-grade lumber and veneer. They do, however, represent a viable, economic soures of raw material for...

  15. Potential for forest products in interior Alaska.

    Science.gov (United States)

    George R. Sampson; Willem W.S. van Hees; Theodore S. Setzer; Richard C. Smith

    1988-01-01

    Future opportunities for producing Alaska forest products were examined from the perspective of timber supply as reported in timber inventory reports and past studies of forest products industry potential. The best prospects for increasing industrial production of forest products in interior Alaska are for softwood lumber. Current softwood lumber production in the...

  16. Band vs. Circular Sawmills: Relative Labor & Maintenance Costs

    Science.gov (United States)

    Philip H. Steele; Philip A. Araman

    1997-01-01

    Substantial sawmill lumber yield increases from kerf and sawing variation reductions can be realized by employing band rather than circular headrigs. Softwood sawmills rapidly adopted bandsaw headrig technology to the extent that it is currently unusual to find circular saw headrigs in a softwood sawmill. Hardwood sawmills, faced with a different economic situation,...

  17. 3D multiscale micromechanical model of wood: From annual rings to microfibrils

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2010-01-01

    A 3D micromechanical analytical-computational model of softwood, which takes into account the wood microstructures at four scale levels, from microfibrils to annual rings, is developed. For the analysis of the effect of the annual rings structure on the properties of softwood, an improved rule-of...

  18. Kiln drying maple for structural uses

    Science.gov (United States)

    Xiping Wang; William T. Simpson; Brian K. Brashaw; Robert J. Ross

    2002-01-01

    Structural lumber products are traditionally manufactured from softwoods. However, with shrinking supplies of softwood lumber and abundant supplies of hardwood lumber, there is increasing interest in the use of hardwoods for structural applications. One factor that will be important in both the technical and economic feasibility of using hardwoods for structural lumber...

  19. Efeito do conteúdo e da natureza da lignina residual na eficiência e na seletividade do branqueamento com ozônio Effect of residual lignin content and nature on the efficiency and selectivity of ozone bleaching

    Directory of Open Access Journals (Sweden)

    Elenice Pereira Maia

    2003-04-01

    Full Text Available Neste estudo foram avaliados os efeitos do conteúdo e da natureza da lignina residual na eficiência e na seletividade do branqueamento com ozônio de polpa kraft convencional (kraft e pré-deslignificada com oxigênio (kraft-O. Constatou-se que a eficiência do branqueamento com ozônio se eleva com o aumento do conteúdo de lignina residual da polpa. O tratamento com ozônio é mais seletivo para polpas kraft-O, mas para um mesmo tipo de polpa a seletividade de branqueamento com ozônio se eleva com o aumento de lignina residual. A eficiência do branqueamento com ozônio aumenta com o teor de lignina fenólica na polpa, entretanto a seletividade é negativamente afetada pela presença destas estruturas.This study aimed to evaluate the effect of residual lignin content and nature on the efficiency and selectivity of ozone bleaching of conventional (kraft and oxygen delignified (kraft-O pulps. Ozone bleaching efficiency was found to be enhanced by increasing pulp residual lignin content. Ozone treatment is more selective for kraft-O pulps, but for a given type of pulp (kraft or kraft-O, ozone bleaching selectivity increases with increasing pulp lignin content. Ozone bleaching efficiency increases with increasing pulp lignin phenolic hydroxyl content whereas selectivity is negatively affected by these structures.

  20. Comparison of various pulping characteristic of Fraxinus angustifolia ...

    African Journals Online (AJOL)

    Handsheets made from different pulping methods were compared with each other for strength and optical properties. Strength properties were found to be higher for kraft and kraft + anthraquinone processes, while optical properties were found to be higher for cold soda and NSSC processes. Key words: Ash, Fraxinus ...

  1. Lignosulfonate To Enhance Enzymatic Saccharification of Lignocelluloses: Role of Molecular Weight and Substrate Lignin

    Science.gov (United States)

    Haifeng Zhou; Hongming Lou; Dongjie Yang; J.Y. Zhu; Xueqing Qiu

    2013-01-01

    This study conducted an investigation of the effect of lignosulfonate (LS) on enzymatic saccharification of lignocelluloses. Two commercial LSs and one laboratory sulfonated kraft lignin were applied to Whatman paper, dilute acid and SPORL (sulfite pretreatment to overcome recalcitrance of lignocelluloses) pretreated aspen, and kraft alkaline and SPORL pretreated...

  2. Lignin solubilisation and gentle fractionation in liquid ammonia

    NARCIS (Netherlands)

    Strassberger, Z.; Prinsen, P.; Klis, van der F.; Es, van D.S.; Tanase, S.; Rothenberg, G.

    2015-01-01

    We present a simple method for solubilising lignin using liquid ammonia. Unlike water, which requires harsh conditions, ammonia can solubilise technical lignins, in particular kraft lignin. A commercial pine wood Kraft lignin (Indulin AT) was solubilized instantaneously at room temperature and 7–11

  3. Pulp quality from small-diameter trees.

    Science.gov (United States)

    G.C. Myers; S. Kumar; R.R. Gustafson; R.J. Barbour; S.M. Abubakr

    1997-01-01

    Kraft and thermomechanical (TMP) pulps were prepared and evaluated from lodgepole pine and mixed Douglas-fir/western larch sawmill residue chips; lodgepole pine, Douglas-fir, and western larch submerchantable logs; and lodgepole pine, Douglas-fir, and western larch small trees and tops. Kraft pulp from small trees and tops was identical to that from submerchantable...

  4. 40 CFR 98.270 - Definition of source category.

    Science.gov (United States)

    2010-07-01

    ... this section: (1) Chemical recovery furnaces at kraft and soda mills (including recovery furnaces that burn spent pulping liquor produced by both the kraft and semichemical process). (2) Chemical recovery... into paperboard products (e.g., containers), or operate coating and laminating processes. (b) The...

  5. 75 FR 76005 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

    Science.gov (United States)

    2010-12-07

    ... production process units include operations such as pulping, bleaching, chemical recovery, and papermaking. Different pulping processes are used, including chemical processes (kraft, soda, sulfite, and semi-chemical... or paperboard products, including: mills that carry out chemical wood pulping (kraft, sulfite, soda...

  6. China's energy revolution - measuring the status quo, modelling regional dynamics & assessing global impacts

    DEFF Research Database (Denmark)

    2015-01-01

    værktøjer er udviklet i denne forbindelse. Den underliggende teori bag forskningen stammer fra en række forskellige discipliner, såsom energi og kraft ingeniørvidenskab, makro- og energi økonomi, samt kraft-projekt finansiering. Det interdisciplinære aspekt udtrykker sig ved harmoniseringen af den Kinesiske...

  7. A comparative study of the hydrolysis of gamma irradiated lignocelluloses

    Directory of Open Access Journals (Sweden)

    E. Betiku

    2009-06-01

    Full Text Available The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis and softwood (Triplochiton scleroxylon were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p < 0.05, hardwood was hydrolysed significantly better compared to the softwood.

  8. Transaction Evidence Appraisal: Competition in British Columbia's Stumpage Markets

    NARCIS (Netherlands)

    Niquidet, K.; Kooten, van G.C.; Cornelis, G.

    2006-01-01

    As a potential resolution to the softwood lumber dispute, the US Department of Commerce recommends that administered stumpage prices in Canada be determined using information from competitive timber auctions. Previous research indicates that the degree of competition significantly influences bidding

  9. Comparison of two cut-to-length harvesting systems operating in eastern hardwoods

    Science.gov (United States)

    Chris B. LeDoux; Niel K. Huyler

    2001-01-01

    We compared production rates, operating costs, and break-even points (BEP) for small and large cut-to-length (CTL) harvesting systems operating at several machine utilization rates (MUR) in mixed hardwood and softwood stands in Vermont.

  10. 7 CFR 1951.9 - Distribution of payments when a borrower owes more than one type of FmHA or its successor agency...

    Science.gov (United States)

    2010-01-01

    ... marginal land converted to the production of softwood timber must be applied on the ST loan(s). (b) Distribution of extra payments. Extra payments will be distributed first to the FmHA or its successor agency...

  11. Midsouth Pulpwood Prices, 1991

    Science.gov (United States)

    Patrick E. Miller

    1993-01-01

    The average delivered price for a cord of Midsouth roundwood in 1991 was $56.39, an increase of 6.5 percent since 1990. Softwood roundwood averaged $58.24 and hardwoods, $50.48 per standard cord, up 2.8 and 7.9 percent, respectively. Chipped residue prices were $26.52 for softwood and $21.0l for hardwood per green ton. The expenditure for wood fiber in the Midsouth...

  12. New legal regulations on combined heat and power generation and renewable energy sources. KWKModG 2009, EEWaermeG, EEG 2009, deadlines for communications, publications and audit certificates according to EEG 2009 and KWKModG 2009; Neuer Gesetzesrahmen fuer die Kraft-Waerme-Kopplung und Erneuerbare Energien. Neues Kraft-Waerme-Kopplungsgesetz (KWKModG 2009), Erneuerbare-Energien-Waermegesetz (EEWaermeG), Erneuerbare-Energien-Gesetz (EEG 2009), Fristen fuer Mitteilungen, Veroeffentlichungen und Wirtschaftspruefertestate nach EEG 2009 und KWKModG 2009

    Energy Technology Data Exchange (ETDEWEB)

    Altrock, Martin; Jacobshagen, Ulf; Lehnert, Wieland [BBH Becker Buettner Held, Berlin (Germany); Miller, John A.; Mueller, Ullrich; Topp, Adolf [AGFW - Der Energieeffizienzverband fuer Waerme, Kaelte und KWK e.V., Frankfurt am Main (Germany)

    2009-07-01

    The new German Act on Combined Heat and Power Generation (KWKModG 2009) is a milestone for the industry. Together with the Heat-from-Renewables Act (EEWaermeG) and the amended Renewables Act (EEG), it will determine the plannings and actions of organizations in this field through 2020 and beyond. This brochure summarizes the three main laws that govern combined heat and power generation and district heating in Germany. The complex legal text is explained in simple terms and supplemented by a multitude of practical hints. There is also an appendix with law texts, exemplary calculations, tables and explanations in digital form. (orig.)

  13. Cynara cardunculus L. alkaline pulps: alternatives fibres for paper and paperboard production.

    Science.gov (United States)

    Abrantes, S; Amaral, M E; Costa, A P; Duarte, A P

    2007-11-01

    The pulping of Cynara cardunculus L. (cardoon) was performed under conditions for kraft, kraft-AQ and soda-AQ processes. The best results in terms of delignification degree, expressed as kappa number, pulp viscosity and screened yield, were obtained for the kraft-AQ process with 0.20% of anthraquinone (AQ). The papermaking potential of the selected pulp was studied attending to biometric fibre characterisation, refining aptitude, optical and strength properties. All properties were compared against a Eucalyptus globulus pulp at different refining degrees. The cardoon pulp was also evaluated concerning its potential to board manufacture, alone and in mixtures with pine pulp, giving rise to promising results for liner manufacture.

  14. Analysis of Kenyan isolates of Fusarium solani f. sp. phaseoli from ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-03

    Jun 3, 2008 ... ... reported worldwide, including Mexico, Brazil, Colombia, Peru, Ecuador, Chile,. Venezuela, Costa Rica and Malawi (Kraft et al., 1981). ... growth, mycelial texture and pigments (colour) produced on the mycelia. The nature of ...

  15. Biobased alkylphenols from lignins via a two-step pyrolysis - Hydrodeoxygenation approach

    NARCIS (Netherlands)

    de Wild, P. J.; Huijgen, W.J.J.; Kloekhorst, A.; Chowdari, R. K.; Heeres, H. J.

    Five technical lignins (three organosolv, Kraft and soda lignin) were depolymerised to produce monomeric biobased aromatics, particularly alkylphenols, by a new two-stage thermochemical approach consisting of dedicated pyrolysis followed by catalytic hydrodeoxygenation (HDO) of the resulting

  16. 78 FR 77782 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-12-24

    ... A. Lawson (KY) Everett H. Logan (OH) Joseph L. Mast (OR) Jesse R. McClary, Sr. (MO) Kevin L. Moody.... Huelster (OK) Roger D. Kloss (IL) Mark D. Kraft (IL) Steven R. Lechtenberg (NE) Thomas W. Markham (MN) Paul...

  17. 40 CFR 62.11610 - Identification of plan.

    Science.gov (United States)

    2010-07-01

    .... The Plan includes the following Kraft Pulp Mills: (1) Chesapeake Corporation, West Point; (2) Stone... operation (added), New design recovery furnace (added), Pulp and paper mill (added), Semichemical pulping...

  18. Rotary klubi tuli rannarahvale appi / Anu Jürisson

    Index Scriptorium Estoniae

    Jürisson, Anu

    2005-01-01

    Tallinna Vanalinna Rotary klubi kinkis kolmele Rannametsa perele kümme tuhat krooni jaanuaritormi kahjustuste likvideerimiseks. Klubi presidendiks on Allan Martinson, nimekirjas ka Tõnis Palts, Toomas Hendrik Ilves, Rein Kilk, Hans H. Luik, Vahur Kraft jt.

  19. 40 CFR 63.861 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... Unit no. HD-14. Kraft pulp mill means any stationary source that produces pulp from wood by cooking... cooking (digesting) wood chips in a solution of sulfurous acid and bisulfite ions. The recovery process...

  20. Alkaline pulping of some eucalypts from Sudan.

    Science.gov (United States)

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper.