Sample records for hardwood kraft black

  1. 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)


    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 In each cook series, a liquor sample was withdrawn at certain time intervals to obtain liquor samples with different chemical composition.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)

  2. Biobutanol production by Clostridium acetobutylicum using xylose recovered from birch Kraft black liquor. (United States)

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


    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.

  3. 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)


    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)

  4. Antioxidant capacity of Kraft black liquor from the pulp and paper industry. (United States)

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


    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.

  5. 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


    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...

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

    Directory of Open Access Journals (Sweden)

    Kátia Maria Morais Eiras


    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.

  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


    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. 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.


    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.

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

    CSIR Research Space (South Africa)

    Namane, M


    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...

  10. 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


    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.

  11. Effects of black liquor shocks on activated sludge treatment of bleached kraft pulp mill wastewater. (United States)

    Morales, Gabriela; Pesante, Silvana; Vidal, Gladys


    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.

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

    International Nuclear Information System (INIS)

    Keiser, J.R.


    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

  13. Electrochemical acidification of Kraft black liquor by electrodialysis with bipolar membrane: Ion exchange membrane fouling identification and mechanisms. (United States)

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


    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.

  14. Comparison the biodiversity of hardwood floodplain forests and black locust forests

    International Nuclear Information System (INIS)

    Bazalova, D.


    The introduction of non-native species starts in the context of global changes in the world. These nonnative species, that have come to our country, whether intentionally or unintentionally, are responsible for the loss of biodiversity, changes in trophic levels and in nutrient cycle, hydrology, hybridizations, and at last could have an impact on the economy. The species black locust (Robinia pseudoaccacia) was introduced to Europe in 1601, first for horticultural purposes, and later broke into forestry. However, due to its ability to effectively spread the vegetative and generative root sprouts seeds and without the presence of natural pest may be occurrence of black locust in European forests highly questionable. Primarily we tried to identify differences in species composition and biodiversity among indigenous hardwood floodplain forest and non-native black locust forest based on numerical methods. In the results we were able to demonstrate more biodiversity in hardwood floodplain forests. (authors)

  15. 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.


    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.

  16. Stirred cell ultrafiltration of lignin from black liquor generated from South African kraft mills

    CSIR Research Space (South Africa)

    Kekana, Paul


    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...

  17. Kraft pulping of industrial wood waste (United States)

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


    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...

  18. 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.


    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.

  19. Carbon distribution in char residue from gasification of kraft black liquor

    International Nuclear Information System (INIS)

    Sricharoenchaikul, Viboon; Frederick, W.J.; Agrawal, Pradeep


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

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


    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.

  1. Removal of COD and color loads in bleached kraft pulp effluents by bottom ashes from boilers. (United States)

    Van Tran, A


    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.

  2. Comparison of two continuous fungal bioreactors for posttreatment of anaerobically pretreated weak black liquor from kraft pulp mills. (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


    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

  3. The Hardwood Tree Improvement and Regeneration Center: its strategic plans for sustaining the hardwood resource (United States)

    Charles H. Michler; Michael J. Bosela; Paula M. Pijut; Keith E. Woeste


    A regional center for hardwood tree improvement, genomics, and regeneration research, development and technology transfer will focus on black walnut, black cherry, northern red oak and, in the future, on other fine hardwoods as the effort is expanded. The Hardwood Tree Improvement and Regeneration Center (HTIRC) will use molecular genetics and genomics along with...

  4. 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)


    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.

  5. Multivariate Analysis of Hemicelluloses in Bleached Kraft Pulp Using Infrared Spectroscopy. (United States)

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


    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.

  6. An approach to industrial application: influence of black liquor and pH on xylanase efficiency in bleaching of eucalyptus kraft pulp


    Fillat Latorre, Úrsula; Roncero Vivero, María Blanca; Bassa, Alexandre; Sacón, Vera Maria


    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...

  7. Anthracnose Diseases of Eastern Hardwoods (United States)

    Frederick H. Berry


    Anthracnose diseases of hardwood trees are widespread throughout the Eastern United States. The most common symptom of these diseases is dead areas or blotches on the leaves. Because of the brown and black, scorched appearance of the leaves, the diseases are sometimes called leaf blight.

  8. Positive and negative aspects of soda/anthraquinone pulping of hardwoods. (United States)

    Francis, R C; Bolton, T S; Abdoulmoumine, N; Lavrykova, N; Bose, S K


    The positive aspects of the non-sulfur soda/anthraquinone (SAQ) process are mostly tied to improved energy efficiency while lower pulp brightness after bleaching is its most significant drawback. A credible method that quantifies bleachability as well as an approach that solves the problem for SAQ pulps from hardwoods will be described. A straight line correlation (R2=0.904) was obtained between O2 kappa number and final light absorption coefficient (LAC) value after standardized OD0EpD1 bleaching of nine hardwood kraft pulps from three laboratories and one pulp mill. The bleachability of pulps from four different soda processes catalyzed by anthraquinone (AQ) and 2-methylanthraquinone (MAQ) was compared to that of conventional kraft pulps by comparing O2 kappa number decrease and final LAC values. It was observed that a mild hot water pre-hydrolysis improved the bleachability of SAQ pulps to a level equal to that of kraft.

  9. Promotion of adventitious root formation of difficult-to-root hardwood tree species (United States)

    Paula M. Pijut; Keith E. Woeste; Charles H. Michler


    North American hardwood tree species, such as alder (Alnus spp.), ash (Fraxinus spp.), basswood (Tilia spp.), beech (Fagus spp.), birch (Betula spp.), black cherry (Prunus seratina), black walnut (Juglans nigra), black willow (...

  10. 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


    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.

  11. Nitrogen oxide emissions from a kraft recovery furnace

    International Nuclear Information System (INIS)

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


    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

  12. 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.


    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)


    Directory of Open Access Journals (Sweden)

    Adriana de Fátima Gomes Gouvêa


    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.

  14. 78 FR 31315 - Kraft Pulp Mills NSPS Review (United States)


    ... 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...

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

    International Nuclear Information System (INIS)

    Inaba, Masamitsu; Meshitsuka, Gyosuke; Nakano, Junzo


    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)

  16. Ground beetle populations near a kraft mill

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  17. 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.


    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)

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

    Directory of Open Access Journals (Sweden)

    Esa Vakkilainen


    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.

  19. Fertilizing Southern Hardwoods (United States)

    W. M. Broadfoot; A. F. Ike


    If present trends continue, fertilizing may soon be economically feasible in southern hardwood stands. Demands for the wood are rising, and the acreage alloted for growing it is steadily shrinking. To supply anticipated requests for information, the U. S. Forest Service has established tree nutrition studies at the Southern Hardwoods Laboratory in Stoneville,...


    Directory of Open Access Journals (Sweden)

    Guanglei Zhao


    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.

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

    International Nuclear Information System (INIS)

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


    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)

  2. 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.


    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.

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

    Directory of Open Access Journals (Sweden)

    Javier Doldán


    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

  4. 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.


    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

  5. 78 FR 38877 - Kraft Pulp Mills NSPS Review (United States)


    ... 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...

  6. Herbicide options for hardwood management (United States)

    Andrew W. Ezell; A. Brady Self


    The use of herbicides in hardwood management presents special problems in that many of the most effective herbicides are either designed to control hardwoods or the product is not labeled for such applications. Numerous studies involving herbicide application in hardwoods have been completed at Mississippi State University. This paper is a compilation of results from...

  7. Swelling and hydrolysis kinetics of Kraft pulp fibers in aqueous 1-butyl-3-methylimidazolium hydrogen sulfate solutions. (United States)

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


    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.

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

    African Journals Online (AJOL)



    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, A.L.


    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.

  10. 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.


    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

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

    Directory of Open Access Journals (Sweden)

    Amadou Diop


    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.

  12. 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.


    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

  13. Dimension yields from short logs of low-quality hardwood trees. (United States)

    Howard N. Rosen; Harold A. Stewart; David J. Polak


    Charts are presented for determining yields of 4/4 dimension cuttings from short hardwood logs of aspen, soft maple, black cherry, yellow-poplar, and black walnut for several cutting grades and bolt sizes. Cost comparisons of short log and standard grade mixes show sizes. Cost comparisons of short log and standard grade mixes show the estimated least expensive...

  14. Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp. (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao


    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.

  15. High consistency cellulase treatment of hardwood prehydrolysis kraft based dissolving pulp. (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao


    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.

  16. Recycling cellulase towards industrial application of enzyme treatment on hardwood kraft-based dissolving pulp. (United States)

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ji, Xingxiang; Ni, Yonghao


    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.

  17. Hardwood sawmill downtime costs (United States)

    Jan Wiedenbeck; Kyle Blackwell


    How time flies when you don't pay attention to it. With hardwood sawmill operating costs ranging from $4 to $25 per operating minute ($95/MBF to $335/MBF) and gross profit margins ranging from $0.10/BF to $0.35/BF, five extra minutes of downtime per day will cost a sawmill that produces an average of 20,000 BF per day (5 MMBF annually) between $21 and $73 per day...

  18. The effect of amphipilic lignin derivatives addition on enzymatic hydrolysis performance of kraft pulp from sorghum bagasse (United States)

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


    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.

  19. Is Eastern Hardwood Sawtimber Becoming Scarcer? (United States)

    William G. Luppold; Gilbert P. Dempsey; Gilbert P. Dempsey


    In recent years the hardwood lumber industry has become increasingly concerned about the availability and quality of hardwood sawtimber. However, these concerns seem to contradict USDA Forest Service estimates of increased volume and quality of hardwood sawtimber. This paper examines changes in eastern hardwood sawtimber inventories and the apparent contradiction...

  20. Studies of lignin transformation in polyoxometalate (POM) bleaching of kraft pulp (United States)

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


    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...

  1. Annotated black walnut literature (United States)

    J. W. Van Sambeek


    Many of our publications on the establishment, management, and utilization of black walnut, butternut, and associated high-value hardwoods are printed in conference proceedings or scientific journals that are not readily available at most public libraries or on the internet. As Chair of the Education Committee, I have tried to summarize for you the relevant findings of...

  2. Chemical Weed Control Increases Survival and Growth in Hardwood Plantings (United States)

    Gayne G. Erdmann


    In a plantation of four hardwood species on a silt loam soil planted to 1-0 stock, 4 pounds of active atrazine or simazine controlled weeds effectively without injuring the trees. Chemical weed control was better on plowed and disked ground than on unprepared ground. Yellow-poplar and white ash grew faster on prepared ground. Black walnut and red oak did not respond...

  3. Ole Bjørn Kraft 1893-1980

    DEFF Research Database (Denmark)

    Skov, Christian Houlberg


    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....


    Directory of Open Access Journals (Sweden)

    Carlos Vila,


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vaaler, David Andre Grimsoeen


    In this thesis, increased hemicellulose retention during kraft pulping has been studied. The work has been divided into three parts: i) Development of an accessible and reliable method for determination of carbohydrate composition of kraft pulps ii) Investigation of the composition and molecular mass distributions of the carbohydrates in kraft pulps with increased hemicellulose content iii) Investigation of the effect of increased hemicellulose content on the sheet properties of kraft pulps with increased hemicellulose content. A method for carbohydrate determination was developed. In this method, enzymes are used to hydrolyse the pulp into monosaccharides. A relatively mild acid hydrolysis is performed prior to detection on an HPLC with an RI-detector. The pulp is not derivatized and no pre-treatment (mechanical or chemical) is needed to determine the carbohydrate composition using the method developed here. Peak deconvolution software is used to improve the accuracy. Polysulphide and H2S primarily increase the glucomannan yield, which can be boosted by up to 7 % on o.d. wood. However, the cellulose yield is more affected by the cooking time and the maximum yield increase of cellulose is approximately 2 % on o.d. wood compared to an ordinary kraft pulp. The cooking time is influenced by sulphide ion concentration, AQ addition and the final Kappa number. The xylan yield is remarkably stable, however the alkali profile during the cook may influence the xylan yield. Surface xylan content of the fibres depends on residual alkali concentration in the black liquor. The molecular mass distributions of cellulose and hemicellulose were determined for pulps with increased hemicellulose content using size exclusion chromatography. Deconvolution by peak separation software is used to gain information about the degree of polymerization for cellulose and hemicellulose. The average DP of glucomannan in the kraft fibre was found to be 350 +- 30 and the average DP of xylan in the

  6. Computer model for economic study of unbleached kraft paperboard production (United States)

    Peter J. Ince


    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...

  7. Recyclable zein-coated kraft paper and linerboard (United States)

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


    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...

  8. 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 ...

  9. Acoustic tomography for decay detection in black cherry trees (United States)

    Xiping Wang; Jan Wiedenbeck; Shanqing Liang


    This study investigated the potential of using acoustic tomography for detecting internal decay in high-value hardwood trees in the forest. Twelve black cherry (Prunus serotina) trees that had a wide range of physical characteristics were tested in a stand of second-growth hardwoods in Kane, PA, using a PiCUS Sonic Tomograph tool. The trees were felled after the field...

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

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


    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.

  11. 1997 Hardwood Research Award Winner: "Automatic Color Sorting of Hardwood Edge-Glued Panel Parts" (United States)

    D. Earl Kline; Richard Conners; Qiang Lu; Philip A. Araman


    The National Hardwood Lumber Association's 1997 Hardwood Research Award was presented to D. Earl Kline, Richard Conners, Qiang Lu and Philip Araman at the 25th Annual Hardwood Symposium for developing an automatic system for color sorting hardwood edge-glued panel parts. The researchers comprise a team from Virginia Tech University and the USDA Forest Service in...

  12. Harvesting costs and utilization of hardwood plantations (United States)

    Tim P. McDonald; Bryce J. Stokes


    The use of short rotation, intensive culture (SRIC) practices in hardwoods to meet fiber supply needs is becoming increasingly widespread. Total plated area of short rotation hardwood fiber plantations is currently about 22,000 ha (McDonald and Stokes 1993). That figure should certainly to grow in response to public concerns over loss of natural hardwood stands. With...

  13. Production of furfural from waste aqueous hemicellulose solution of hardwood over ZSM-5 zeolite. (United States)

    Gao, Hongling; Liu, Haitang; Pang, Bo; Yu, Guang; Du, Jian; Zhang, Yuedong; Wang, Haisong; Mu, Xindong


    This study aimed to produce furfural from waste aqueous hemicellulose solution of a hardwood kraft-based dissolving pulp production processing in a green method. The maximum furfural yield of 82.4% and the xylose conversion of 96.8% were achieved at 463K, 1.0g ZSM-5, 1.05g NaCl and organic solvent-to-aqueous phase ratio of 30:15 (V/V) for 3h. The furfural yield was just 51.5% when the same concentration of pure xylose solution was used. Under the optimized condition, furfural yield was still up to 67.1% even after the fifth reused of catalyst. Catalyst recycling study showed that ZSM-5 has a certain stability and can be efficiently reused. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Effects of herbicide release on the growth of 8- to 12-year-old hardwood trees (United States)

    G.W. Wendel; Neil I. Lamson; Neil I. Lamson


    In 8- to 12-year-old Appalachian hardwood stands, crop trees were released by stem injecting competing trees with a 20 percent aqueous solution of glyphosate. Species released were black cherry, red oak, and sugar maple. Release treatments were (a) injection of all trees within a 5-foot radius of the crop tree bole and (b) injections of all trees whose crown touched...

  15. Growth and Survival of Hardwoods and Pine Interplanted with European Alder (United States)

    William T. Plass


    European black alder is recommended for planting on many surface mine spoils in the eastern United States. It grows rapidly on a range of spoil types and contributes to soil enrichment by fixing nitrogen and providing a leaf fall rich in nutrients. This study evaluated the effect of alder on the survival and growth of five hardwood and five pine species. After 10...

  16. Silviculture-ecology of forest-zone hardwoods in the Sierra Nevada (United States)

    Philip M. McDonald; John C. Tappeiner


    Although the principal hardwood species in the forest zone of the Sierra Nevada (California black oak, tanoak, Pacific madrone, and canyon live oak) are key components of many ecosystems, they have received comparatively little study. Currently they are underutilized and unmanaged. This paper brings together what is known on the silviculture-ecology of these species...

  17. Silviculture-ecology of three native California hardwoods on high sites in north central California (United States)

    Philip M. McDonald


    Pacific madrone, tanoak, and California black oak are the most economically promising native California hardwoods. Volume and value data indicate upward trends in growing stock levels and prices received for their products. These trends are likely to continue. They suggest research is particularly needed for: (1) seed fall and regeneration, (2) sprout growth and...

  18. California’s Hardwood Resource: Seeds, Seedlings, and Sprouts of Three Important Forest-Zone Species (United States)

    Philip M. McDonald; John C. Tappeiner


    Although California black oak, tanoak, and Pacific madrone are the principal hardwood species in the forest zone of California and Oregon and are key components of many plant communities, their seed production, regeneration, and early growth requirements have received little study. Information is presented on seed production, storage, and germination, and on the...

  19. A Stocking Guide for Allegheny Hardwoods and Its Use in Controlling Intermediate Cuttings (United States)

    Benjamin A. Roach


    A stocking guide for stands of Allegheny hardwoods (sugar maple or sugar maple-beech with varying admixtures of black cherry, red maple, white ash, sweet birch, and other species) on the Allegheny Plateau in northwestern Pennsylvania. Included are procedures for evaluating stocking and stand conditions, thinning even-aged stands, determining minimum residual stocking,...

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


    Ribeiro, Sara Isabel de Paula


    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. ...

  1. Drying hardwood lumber

    Energy Technology Data Exchange (ETDEWEB)

    Chow, A T


    Dried lumber is a high-value-added product, especially when it is of high quality. Lumber damaged during the drying operation can represent substantial lost revenue. It has been demonstrated that dehumidification kilns can improve lumber quality, and reduce energy consumption over conventional drying methods. A summary of the literature on drying hardwood lumber, particularly using heat pump dehumidification, has been prepared to allow the information to be readily accessible to Ontario Hydro personnel who work with customers in the lumber industry. For that purpose, this summary has been prepared from the perspective of the customer, a dry kiln operator. Included are brief descriptions of drying schedules, precautions needed to minimize drying defects in the lumber, and rules-of-thumb for selecting and estimating the capital cost of the drying equipment. A selection of drying schedules and moisture contents of green lumber, a glossary of lumber defects and brief descriptions of the possible preventive measures are also included. 10 refs., 8 figs., 4 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Simo Sarkanen


    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

  3. Internationalisation; KonKraft-rapport 4; Internasjonalisering

    Energy Technology Data Exchange (ETDEWEB)


    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

  4. An Examination of Regional Hardwood Roundwood Markets in West Virginia (United States)

    William Luppold; Delton Alderman; Delton Alderman


    West Virginia?s hardwood resource is large and diverse ranging from oak-hickory forests in the southern and western portions of the state to northern hardwood stands in the northeastern region. West Virginia also has a diverse group of primary hardwood- processing industries, including hardwood grade mills, industrial hardwood sawmills, engineered wood-product...

  5. Strategic plans for the Hardwood Tree Improvement and Regeneration Center (United States)

    Charles H. Michler; Keith E. Woeste


    The mission of the Hardwood Tree Improvement and Regeneration Center (HTIRC) at Purdue University is to advance the science of hardwood tree improvement and genomics in the central hardwood region of the United States by: developing and disseminating knowledge on improving the genetic quality of hardwood tree species; conserving fine hardwood germplasm; developing...

  6. Research on combustion of black-liquor drops

    International Nuclear Information System (INIS)

    Macek, A.


    Black liquor, the major by-product of the kraft process for production of pulp, is one of the most important industrial fuels. It is burned in recovery boilers in the form of large spray drops (mm), with the objective of simultaneous recovery of heat and chemicals (sodium and sulfur). Even though black-liquor combustion in boilers has been practised for over half a century, research efforts toward improvement of combustion efficiency and abatement of environmental emissions are much more recent. The present paper addresses a specific aspect of that research, namely, elucidation of processes which occur during combustion of black-liquor drops in boiler-gas streams. The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the 1980s and 1990s, (c) re-examines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in recovery boilers, and (d) recommends input for the modeling of in-flight combustion of kraft-liquor drops in recovery boilers. (author)

  7. 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


    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.

  8. Marketing Hardwoods to Furniture Producers (United States)

    Steven A. Sinclair; Robert J. Bush; Philip A. Araman


    This paper discusses some of the many problems in developing marketing programs for small wood products manufacturers. It examines the problems of using price as a dominant means for getting and attracting customers. The marketing of hardwood lumber to furniture producers is then used as an example. Data from 36 furniture lumber buyers is presented to illustrate...

  9. Bottomland Hardwood Ecosystem Management Project (United States)

    John A. Stanturf; Calvin E. Meier


    Federal agency approaches to land management are undergoing a shift from parcel-specific concerns toward a more holistic, ecosystem management approach. Southern bottomland hardwood ecosystems provide important environmental services and commodity goods (Wharton et al. 1982), yet much of our knowledge of these systems comes from anecdotal information. The Bottomland...

  10. Soil Management for Hardwood Production (United States)

    W. M. Broadfoot; B. G. Blackmon; J. B. Baker


    Soil management is the key to successful hardwood management because soil properties are probably the most important determinants of forest productivity. Because of the lack of soil uniformity, however, many foresters have become frustrated with attempts to relate soil to satisfactory growth. Since soil scientists have been unable to predict site quality for trees in...

  11. Agrobacterium-mediated transformation of black cherry for flowering control and insect resistance (United States)

    Ying Wang; Paula M. Pijut


    Black cherry is one of the most valuable hardwood species for cabinetry, furniture, and veneer. The goal of this study was to develop transgenic black cherry plants with reproductive sterility and enhanced insect resistance. Black cherry TERMINAL FLOWER 1 (PsTFL1) was overexpressed under the control of the CaMV 35S promoter in black cherry via

  12. Planting and care of fine hardwood seedlings: Planting hardwood seedlings in the Central Hardwood Region. (United States)

    Paula M. Pijut


    Forest tree planting in the United States on public and private land exceeded 2.6 million acres in 1999. Of that total, approximately 1.3 million acres (48 percent) were planted by private individuals (AF & PA 2001). In the Central Hardwood Region forest tree planting by private landowners exceeded 100,000 acres in 1999. Trees are planted for various reasons...

  13. Utilization of the Eastern Hardwood Resource by the Hardwood Sawmilling Industry (United States)

    William Luppold; John Baumgras; John Baumgras


    The eastern hardwood resource contains numerous species that differ in grain, color, texture, and workability. Because the value of hardwoods is derived from appearance, these variations in physical attributes can cause the price for identical grades of hardwood lumber to vary by as much as 600% between species. As a result, there is incentive for primary processors to...

  14. The state of hardwood lumber markets (United States)

    Gilbert P. Dempsey; William G. Luppold


    Although the 1990-91 recession has temporarily dampened the demand for hardwood lumber, the decade of the 1980s was a period of strong growth in the hardwood market. After experiencing a flat market in 1980 and a decline in 1982, the demand for hardwood lumber by both the domestic industry and the export market increased strongly—from 8 billion board feet in 1982 to 11...

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


    V. S. Pai; Ram Subramanian


    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Ulrike W. Tschirner; Timothy Smith


    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.

  17. Hardwood supply in the Pacific Northwest-a policy perspective. (United States)

    Terry L. Raettig; Kent P. Connaughton; Glenn R. Ahrens


    The policy framework for the hardwood resource and hardwood industry in western Oregon and Washington is examined. Harvesting trends, harvesting behavior of public and private landowners, and harvesting regulation are presented to complete the analysis of factors affecting short-run hardwood supply. In the short term, the supply of hardwoods is generally favorable, but...

  18. Low-grade hardwood lumber production, markets, and issues (United States)

    Dan Cumbo; Robert Smith; Philip A. Araman


    Due to recent downturn in the economy and changes in traditional hardwood markets. U.S. hardwood manufacturers are facing significant difficulties. In particular, markets for low-grade lumber have been diminishing, while increased levels of the material are being produced at hardwood sawmills in the United States. A nationwide survey of hardwood lumber manufacturers...

  19. Gluing of Eastern Hardwoods: A Review (United States)

    Terry Sellers; James R. McSween; William T. Nearn


    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...

  20. Automatic Edging and Trimming of Hardwood Lumber (United States)

    D. Earl Kline; Eugene M. Wengert; Philip A. Araman


    Studies have shown that there is a potential to increase hardwood lumber value by more than 20 percent through optimum edging and trimming. Even a small portion of this percentage can boost the profitability of hardwood lumber manufacturers substantially. The objective of this research project is to develop an automated system which would assist in correct edging and...

  1. 77 FR 71017 - Hardwood Plywood From China (United States)


    ...)] Hardwood Plywood From China Determinations On the basis of the record \\1\\ developed in the subject... plywood from China that are allegedly subsidized and sold in the United States at less than fair value... and subsidized imports of hardwood plywood from China. Accordingly, effective September 27, 2012, the...

  2. Sources of the Indiana hardwood industry's competitiveness (United States)

    Silas Tora; Eva Haviarova


    The estimated 1,600 forest products-related firms in Indiana employ more than 56,000 workers. Hardwood manufacturers are the largest segment, adding approximately $2 billion per year of raw product value. A recent report by BioCrossroads ranked the hardwood industry as the most important in the agricultural sector in Indiana. Like most of the other forest products...

  3. The pallet industry: a changing hardwood market (United States)

    G.P. Dempsey; D.G. Martens


    From its inception during World War II, the wooden pallet industry has grown to become the Nation's largest industrial consumer of hardwood lumber products. Since most of the raw material in wooden pallets is lower grade lumber, the pallet industry's growth, efficiency, and changing raw material inputs must be of concern to the grade hardwood lumber industry...

  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. 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


    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...

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

    Directory of Open Access Journals (Sweden)

    Widya Fatriasari


    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.

  7. Furfural formation from the pre-hydrolysis liquor of a hardwood kraft-based dissolving pulp production process. (United States)

    Liu, Haitang; Hu, Huiren; Jahan, M Sarwar; Ni, Yonghao


    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.

  8. Production and cost analysis of a feller-buncher in central Appalachian hardwood forest (United States)

    Charlie Long; Jingxin Wang; Joe McNeel; John Baumgras; John Baumgras


    A time study was conducted to evaluate the productivity and cost of a feller-buncher operating in a Central Appalachian hardwood forest. The sites harvested during observation consisted of primarily red maple and black cherry. Trees felled in the study had an average diameter at breast height (DBH) of 16.1 in. and a total merchantable height of 16 ft. A Timbco 445C...

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

    International Nuclear Information System (INIS)

    Rabelo, Marcos Sousa


    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)

  10. Conversion of kraft lignin over hierarchical MFI zeolite. (United States)

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


    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.

  11. Study on the Modification of Bleached Eucalyptus Kraft Pulp Using Birch Xylan (United States)

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


    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...

  12. Response of northern red oak, black walnut, and white ash seedlings to various levels of simulated summer deer browsing (United States)

    Robert C. Morrissey; Douglass F. Jacobs; John R. Seifert


    Understanding the response of tree seedlings to browsing by white-tailed deer (Odocoileus virginianus Zimmerman) is critical to the management of high value hardwood plantations in the Central Hardwood Forest Region. One-year-old black walnut (Juglans nigra L.), northern red oak (Quercus rubra L.), and white ash...

  13. 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)


    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.

  14. 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


    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.

  15. Quercus kelloggii Newb., California black oak (United States)

    P.M. McDonald


    California black oak (Quercus kelloggii) exceeds all other California oaks in volume, distribution, and altitudinal range. Yet this deciduous hardwood has had little sustained commercial use and almost no management, even though its wood closely resembles that of its valuable, managed, and heavily used counterpart-northern red oak (...

  16. Heartwood formation in four black walnut plantations (United States)

    Keith Woeste; Brian Beheler


    The amount of heartwood in black walnut (Juglans nigra L.) logs can vary widely, even among trees of the same age growing at the same location. There is little published data on the genetics, physiology, and development of heartwood in hardwoods, even though the volume of heartwood in a log can significantly influence its value.

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

    Directory of Open Access Journals (Sweden)

    Xian-fa Li


    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.

  18. Management and inventory of southern hardwoods (United States)

    John A. Putnam; George M. Furnival; J.S. McKnight


    The valleys and uplands of the South outside the mountains and upper Piedmont have, since 1915, been responsible for about 45 percent of the national production of hardwood sawtimber. They are strong indications that this situation may continue indefinitely.

  19. Bottomland Hardwood Planting: Example Contract Specifications

    National Research Council Canada - National Science Library

    Humprey, Monica


    This technical note provides an example of contract specifications that can be used as a template by USACE biologists, engineers, or contracting officers for contracting the planting of bottomland hardwood (BLH) seedlings...

  20. 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


    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

  1. California's hardwood resource: history and reasons for lack of a sustained hardwood industry (United States)

    Dean W. Huber; Philip M. McDonald


    Interest in utilizing California's forest-zone hardwoods for lumber and wood products has waxed and waned for more than 140 years. In spite of many unsuccessful ventures, strong interest is once again evident from landowners, processors, consumers, and policy makers. Their interest suggests a need to know past pitfalls, to recognize some realities of hardwood...

  2. Planting and care of fine hardwood seedlings: Nursery production of hardwood seedlings (United States)

    Douglass F. Jacobs


    Access to quality tree seedlings is an essential component of a successful hardwood reforestation project. Hardwood plantations may be established by sowing seed directly to a field site, but the success of direct seeding operations has been inconsistent for many species, which indicates that more research is needed before this practice can be recommended. For...

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Rasoul Darstan


    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.

  5. A multi-criteria decision analysis of management alternatives for anaerobically digested kraft pulp mill sludge (United States)

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


    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

  6. Visual Spatial Disorientation: Re-Visiting the Black Hole Illusion (United States)


    National Transportation Safety Board. Controlled Flight into Terrain, Korean Air Flight 801 , Nimitz Hill, Guam; 1997. 50. National Transportation Safety...According to a Boeing study of worldwide commercial airline accidents, the approach and landing phase of flying, although only accounting for 4% of the...VISUAL SPATIAL DISORIENTATION Kraft (31) described four night visual, landing airline accidents. Black Hole Illusion 5 1. In 1965, a United Airlines

  7. Evaluation of bleachability on pine and eucalyptus kraft pulps

    Directory of Open Access Journals (Sweden)

    Marcela Freitas Andrade


    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.

  8. Characterization of Cypress Wood for Kraft Pulp Production

    Directory of Open Access Journals (Sweden)

    António J. A. Santos


    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.

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

    Directory of Open Access Journals (Sweden)

    Camila Sarto


    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.

  10. A management guide for northern hardwoods in New England (United States)

    Adrian M. Gilbert; Victor S. Jensen


    Northern hardwood forests occupy about 9 million acres of land in New England. In recent years, these hardwood forests have made increasing contributions to the economy of this region. Their future management should be even more rewarding.

  11. 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

  12. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes. (United States)


    ... 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...

  13. Are there regional differences in US hardwood product exports? (United States)

    Matt Bumgardner; Scott Bowe; William Luppold


    Exporting is a critical component of the product mix for many domestic hardwood firms. Previous research has identified factors associated with hardwood lumber exporting behavior, but less is known about the advantages and disadvantages to exporting associated with the region within which a firm is located, or about exporting of secondary hardwood products. A procedure...

  14. Growth and shifts in eastern hardwood lumber production (United States)

    William G. Luppold; Gilbert P. Dempsey


    An analysis of recent trends in eastern U.S. hardwood lumber production indicates that total output increased sharply between 1977 and 1991. The increase, however, was much more pronounced in the East's northern tier of states than in the southern. This paper first examines recent hardwood lumber usage trends and historic hardwood lumber production trends. Changes...

  15. 40 years of hardwood lumber comsumption: 1963 to 2002 (United States)

    William Luppold; Matthew Bumgardner


    An analysis of hardwood lumber consumption found that demand has changed dramatically over the past four decades as a result of material substitution, changes in construction and remodeling products markets, and globalization. In 1963 furniture producers consumed 36 percent of the hardwood products lumber used by domestic manufacturers. Producers of hardwood...

  16. U.S. Hardwood Imports Grow as World Supplies Expand (United States)

    William C. Siegel; Clark Row


    Rapidly increasing imports have captured a significant share of America's hardwood markets. Total imports of hardwood raw materials and building products are now four times as large as exports. Before World War II the U. S. was a net exporter of hardwoods, and imports were limited to high-quality mahogany and specialty logs and lumber. Availability of large...

  17. Effect of vertical integration on the utilization of hardwood resources (United States)

    Jan Wiedenbeck


    The effectiveness of vertical integration in promoting the efficient utilization of the hardwood resource in the eastern United States was assessed during a series of interviews with vertically integrated hardwood manufacturers in the Appalachian region. Data from 19 companies that responded to the 1996 phone survey indicate that: 1) vertically integrated hardwood...

  18. Simultaneous and rapid determination of multiple component concentrations in a Kraft liquor process stream (United States)

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


    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.

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


    Mocelin, Ezequiel Zatoni


    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 ...

  20. Detoxification of kraft pulp ECF bleaching effluents by catalytic hydrotreatment. (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yulin Deng; Art Ragauskas


    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

  2. Planting and care of fine hardwood seedlings: Diagnosing and controlling wildlife damage in hardwood plantations. (United States)

    James McKenna; Keith Woeste


    Once trees are planted and begin growing, damage from wildlife can threaten their quality. In this publication we discuss how to identify and manage injury to hardwoods from wildlife to minimize losses.

  3. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander


    Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as is hi...


    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 ...

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

    Directory of Open Access Journals (Sweden)

    Shanhui Wang


    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.

  6. Reinforcing Natural Rubber with Cellulose Nanofibrils Extracted from Bleached Eucalyptus Kraft Pulp (United States)

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


    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...

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

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

    NARCIS (Netherlands)

    Warit, J.


    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

  9. 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


    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.

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

    Qianqian Wang; Xuebing Zhao; J.Y. Zhu


    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...

  11. Development of hemicelluloses biorefineries for integration into kraft pulp mills (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

  12. Fundamental Study of Black Liquor Gasification Kinetics. Quarterly progress report for the period October 1999 to December 1999

    Energy Technology Data Exchange (ETDEWEB)



    The overall objective of this research is to evaluate the kinetics of gasification of kraft black liquor under laboratory conditions simulating pressurized, oxygen-blown gasification. The significant independent variables are gasifier temperature, black liquor composition particle size, and particle residence time. The authors will quantify their impact on the concentration of major and trace gas phase species, as well as the composition of condensed phase inorganic products, including specification of the Na- and S-containing compounds and overall carbon conversion.

  13. Precipitation and valorisation of lignin in South African kraft mill black liquor - first stages: Poster

    CSIR Research Space (South Africa)

    Namane, M


    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...

  14. Precipitation and valorisation of lignin obtained from South African Kraft mill black liquor

    CSIR Research Space (South Africa)

    Namane, Mpho


    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...

  15. 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)


    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.

  16. A Dynamic Model of California's Hardwood Rangelands (United States)

    Richard B. Standiford; Richard E. Howitt


    Low profitability of hardwood rangeland management, and oak tree harvesting for firewood markets and forage enhancement has led to concern about the long-term sustainability of the oak resource on rangelands. New markets for recreational hunting may give value to oaks for the habitat they provide for game species, and broaden the economic base for managers. A ranch...

  17. Guide to Regeneration of Bottomland Hardwoods (United States)

    Martha R. McKevlin


    This guide will help landowners, consulting foresters, and public service foresters regenerate bottomland hardwoods. It discusses (1) interpretation of site characteristics, (2) selection of species, and (3) selection of regeneration methods. A dichotomous key for selection of appropriate regeneration methods under various conditions is presented.

  18. Placing our northern hardwood woodlots under management (United States)

    Russell J. Hutnik


    Do you own a woodlot? Does it contain mostly northern hardwoods - that is, beech, birch, maple, and ash, with some hemlock and spruce? If the answers to these two questions are "yes," then you may be interested in the work that is carried on at the Bartlett Experimental Forest in New Hampshire. This is one of the field laboratories established by the U. S....

  19. Efficient silvicultural practices for eastern hardwood management (United States)

    Gary W. Miller; John E. Baumgras


    Eastern hardwood forests are now managed to meet a wide range of objectives, resulting in the need for silvicultural alternatives that provide timber, wildlife, aesthetics, recreation, and other benefits. However, forest management practices must continue to be efficient in terms of profiting from current harvests, protecting the environment, and sustaining production...

  20. Sampling the quality of hardwood trees (United States)

    Adrian M. Gilbert


    Anyone acquainted with the conversion of hardwood trees into wood products knows that timber has a wide range in quality. Some trees will yield better products than others. So, in addition to rate of growth and size, tree values are affected by the quality of products yielded.

  1. Chapter 10:Hardwoods for timber bridges (United States)

    James P. Wacker; Ed T. Cesa


    This chapter describes the joint efforts of the Forest Service and the FHWA to administer national programs including research, demonstration bridges, and technology transfer components. Summary information on a number of Forest Service-WIT demonstration bridges constructed with hardwoods is also provided.

  2. Proceedings, 15th central hardwood forest conference (United States)

    David S. Buckley; Wayne K. Clatterbuck; [Editors


    Proceedings of the 15th central hardwood forest conference held February 27–March 1, 2006, in Knoxville, TN. Includes 86 papers and 30 posters pertaining to forest health and protection, ecology and forest dynamics, natural and artificial regeneration, forest products, wildlife, site classification, management and forest resources, mensuration and models, soil and...

  3. Proceedings 19th Central Hardwood Forest Conference (United States)

    John W. Groninger; Eric J. Holzmueller; Clayton K. Nielsen; Daniel C., eds. Dey


    Proceedings from the 2014 Central Hardwood Forest Conference in Carbondale, IL. The published proceedings include 27 papers and 47 abstracts pertaining to research conducted on biofuels and bioenergy, forest biometrics, forest ecology and physiology, forest economics, forest health including invasive species, forest soils and hydrology, geographic information systems,...

  4. Automation for Primary Processing of Hardwoods (United States)

    Daniel L. Schmoldt


    Hardwood sawmills critically need to incorporate automation and computer technology into their operations. Social constraints, forest biology constraints, forest product market changes, and financial necessity are forcing primary processors to boost their productivity and efficiency to higher levels. The locations, extent, and types of defects found in logs and on...

  5. Stocking chart for upland central hardwoods (United States)

    Martin E. Dale; Donald E. Hilt


    The upland hardwoods stocking chart, introduced by Gingrich in 1967, has become one of the forest manager's most useful tools. The chart allows you to determine the condition of the present stand in relation to a stocking standard. The stocking of a stand is extremely helpful in prescribing various silvicultural treatments such as intermediate thinnings,...

  6. Harvesting systems for the northern forest hardwoods (United States)

    Chris B. LeDoux


    This monograph is a summary of research results and environmental compliance measures for timber harvesting operations. Data are presented from the Northern Research Station's forest inventory and analysis of 20 states in the northern forest hardwoods. Harvesting systems available in the region today are summarized. Equations for estimating harvesting costs are...

  7. A Guide to Bottomland Hardwood Restoration (United States)


    floristically Ecological Importance of Understory diverse undergrowth may serve to pollinate flowers, Plants including those of trees. Undergrowth vegetation...Herbaceous plants include bedstraw, Variants and associated vegetation. Sycamore- violet, wild carrot, wild lettuce , amsonia, mint, legumes, pecan...elements of bottomland hardwood restoration such as species selection, site preparation, direct seeding, planting of seedlings, and alternative

  8. Defining Hardwood Veneer Log Quality Attributes (United States)

    Jan Wiedenbeck; Michael Wiemann; Delton Alderman; John Baumgras; William Luppold


    This publication provides a broad spectrum of information on the hardwood veneer industry in North America. Veneer manufacturers and their customers impose guidelines in specifying wood quality attributes that are very discriminating but poorly defined (e.g., exceptional color, texture, and/or figure characteristics). To better understand and begin to define the most...

  9. Bottomland hardwood afforestation: State of the art (United States)

    Emile S. Gardiner; D. Ramsey Russell; Mark Oliver; Lamar C. Dorris


    Over the past decade, land managers have implemented large-scale afforestation operations across the Southern United States to rehabilitate agricultural land historically converted from bottomland hardwood forest cover types. These afforestation efforts were initially concentrated on public land managed by State or Federal Government agencies, but have later shifted...

  10. Applying group selection in upland hardwoods (United States)

    Gary w. Miller; H. Clay Smith


    Interest in applying group selection in upland hardwoods has grown in recent years, primarily in response to public opposition to the aesthetic effects of clearcutting. Critics suggest that an uneven-aged silvicultural practice such as group selection might be a suitable compromise--drastically reducing negative visual effects of harvesting trees while continuing to...

  11. 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


    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...


    Directory of Open Access Journals (Sweden)

    Gabriel Valim Cardoso


    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

  13. Relationship between lignin structure and delignification degree in Pinus pinaster kraft pulps. (United States)

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


    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.

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

    Directory of Open Access Journals (Sweden)

    Yi Hou


    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.

  15. 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.


    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)

  16. Information Sharing in the Hardwood Supply Chain


    Stiess, Timothy Stephen


    The Hardwood Industry in United States has been challenged by low-cost competition from overseas. Although cost reduction strategies have had minimal success, the proximity of industry to the domestic market has large implications on a more customer-focused strategy. The problem arises that individual companies and supply chains evolved based on the principles of economies of size and not on the flexibility to adapt to customer needs and changing resource constraints. An increased rate at ...

  17. Alkali-treated kraft lignin as a component in flakeboard eesins (United States)

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


    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-...



    Ulf Germgard; Muhammad Asif Javed


    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...

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

    Directory of Open Access Journals (Sweden)

    Chandranupap, P.


    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.

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

    International Nuclear Information System (INIS)

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


    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

  1. Kraft lignin chain extension chemistry via propargylation, oxidative coupling, and Claisen rearrangement. (United States)

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


    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.

  2. Soda-anthraquinone, kraft and organosolv pulping of holm oak trimmings. (United States)

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


    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.

  3. Drop formation of black liquor spraying; Mustalipeaen pisaroituminen

    Energy Technology Data Exchange (ETDEWEB)

    Fogelholm, C J; Kankkunen, A; Nieminen, K; Laine, J; Miikkulainen, P [Helsinki Univ. of Technology, Otaniemi (Finland): Lab. of Energy Technology and Environmental Protection


    Black liquor is a spent liquor of the pulp and paper industry. It is burned in kraft recovery boilers for chemical and energy recovery. The high dry solids content and viscosity of black liquor require a high spraying temperature. This affects the performance of the boiler. Kraft recovery boiler deposit formation, emissions and chemical recovery are strongly affected by the drop size and the velocity of the black liquor spray formed by a splashplate nozzle. The sheet breakup mechanism is studied with a system based on a video and image-analysis. The drop size of mill-scale nozzles was measured also with an image-analysis-system. Measurements were carried out in a spray test chamber. The sheet breakup mechanism and drop size tests were carried out both below and over the boiling point of black liquor. Special attention was paid to the effect of flashing on drop formation. Temperature increase normally decreases drop size. In the temperature where the wavy-sheet disintegration changes to perforated-sheet disintegration the drop size increases. Spray velocity rises when the temperature is increased above the boiling point. (orig.)

  4. 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)


    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.

  5. Researching effects of prescribed fire in hardwood forests (United States)

    Stacy L. Clark; Kathleen E. Franzreb; Cathryn H. Greenberg; Tara Keyser; Susan C. Loeb; David L. Loftis; W. Henry McNab; Joy M. O' Keefe; Callie Jo Schweitzer; Martin Spetich


    The Upland Hardwood Ecology and Management Research Work Unit (RWU 4157) is a group of research teams located across the South, strategically placed to conduct research in physiographic sub-regions of the upland hardwood ecosystems including the southern Appalachian Mountains, the Cumberland Plateau, the Boston Mountains, and the Missouri Plateau. Our RWU is one of 16...

  6. An econometric model of the hardwood lumber market (United States)

    William G. Luppold


    A recursive econometric model with causal flow originating from the demand relationship is used to analyze the effects of exogenous variables on quantity and price of hardwood lumber. Wage rates, interest rates, stumpage price, lumber exports, and price of lumber demanders' output were the major factors influencing quantities demanded and supplied and hardwood...

  7. Spectral reflectance of five hardwood tree species in southern Indiana (United States)

    Dale R. Weigel; J.C. Randolph


    The use of remote sensing to identify forest species has been ongoing since the launch of Landsat-1 using MSS imagery. The ability to separate hardwoods from conifers was accomplished by the 1980s. However, distinguishing individual hardwood species is more problematic due to similar spectral and phenological characteristics. With the launch of commercial satellites...

  8. Match Your Hardwood Lumber to Current Market Needs (United States)

    Robert J. Bush; Steven A. Sinclair; Philip A. Araman


    This article explains how hardwood lumber producers can best market their product. The study included four segments of the market for hardwood lumber. These segments were: furniture, cabinet, dimension and flooring, and molding/millwork manufacturers. The article explains how the study was conducted and the characteristics of companies (i.e., potential customers) that...

  9. Silvicultural guide for northern hardwoods in the northeast (United States)

    William B. Leak; Mariko Yamasaki; Robbo. Holleran


    This revision of the 1987 silvicultural guide includes updated and expanded silvicultural information on northern hardwoods as well as additional information on wildlife habitat and the management of mixed-wood and northern hardwood-oak stands. The prescription methodology is simpler and more field-oriented. This guide also includes an appendix of familiar tables and...

  10. On Tour... Primary Hardwood Processing, Products and Recycling Unit (United States)

    Philip A. Araman; Daniel L. Schmoldt


    Housed within the Department of Wood Science and Forest Products at Virginia Polytechnic Institute is a three-person USDA Forest Service research work unit (with one vacancy) devoted to hardwood processing and recycling research. Phil Araman is the project leader of this truly unique and productive unit, titled ãPrimary Hardwood Processing, Products and Recycling.ä The...

  11. Do region and gender influence hardwood product selection? (United States)

    Delton Alderman


    Consumer preference is a fundamental focus of marketing research as it is used in developing marketing strategy and the positioning of products against competitors. This study evaluated consumer hardwood preferences of consumers from three United States geographical regions, which included six different metropolitan areas. Seven hardwood species and three laminate...

  12. Factors affecting regional changes in hardwood lumber production (United States)

    William G. Luppold; Gilbert P. Dempsey; Gilbert P. Dempsey


    Hardwood lumber production increased by nearly 1.8 billion board feet between 1986 and 1990 and decreased sharply in 1991. However, not all areas of the country experienced the same growth in hardwood lumber production during the 1980s. While lumber production in inland regions of the eastern United States and the west increased during the 1980s, lumber output in...

  13. Hardwood lumber supply chain: current status and market opportunities (United States)

    Urs Buehlmann; Matthew Bumgardner; Al Schuler; Mark Barford


    The membership of the Appalachian Hardwood Manufacturers Association was surveyed in 2005 to determine the current status of large Appalachian sawmills. The primary focus was to assess the impacts of globalization on primary manufacturing, but attention was also paid to general issues affecting the hardwood lumber supply chain-from concerns over forest health and log...

  14. A new tree classification system for southern hardwoods (United States)

    James S. Meadows; Daniel A. Jr. Skojac


    A new tree classification system for southern hardwoods is described. The new system is based on the Putnam tree classification system, originally developed by Putnam et al., 1960, Management ond inventory of southern hardwoods, Agriculture Handbook 181, US For. Sew., Washington, DC, which consists of four tree classes: (1) preferred growing stock, (2) reserve growing...

  15. Exploring research priorities for the North American hardwood industry (United States)

    David Brinberg; Earl Kline; Delton Alderman; Philip Araman; Ed Cesa; Steve Milauskas; Tom Walthousen; Jan Wiedenbeck


    With the increase of globalization, the North American hardwood industry is facing many challenges to remain competitive and sustainable, facing drastic changes in the areas of labor, land, manufacturing, markets and marketing, and supply chain. The hardwood industry is especially vulnerable, with the influx of foreign manufacturers and suppliers with greater natural...

  16. Southern hardwood forestry group going strong after 50 years (United States)

    Brian Roy Lockhart; Steve Meadows; Jeff Portwood


    On November 15,200 1, the Southern Hardwood Forestry Group (referred to as the Group) met at the U.S. Forest Service Southern Research Station's Southern Hardwoods Laboratory in Stoneville, hlississippi to celebrate the Group's 50th anniversary. About 130 members and guests attended to celebrate the 50th anniversary of the Group and to honor its charter...

  17. Nondestructive evaluation of incipient decay in hardwood logs (United States)

    Xiping Wang; Jan Wiedenbeck; Robert J. Ross; John W. Forsman; John R. Erickson; Crystal Pilon; Brian K. Brashaw


    Decay can cause significant damage to high-value hardwood timber. New nondestructive evaluation (NDE) technologies are urgently needed to effectively detect incipient decay in hardwood timber at the earliest possible stage. Currently, the primary means of inspecting timber relies on visual assessment criteria. When visual inspections are used exclusively, they provide...

  18. Hardwood genetics and tree improvement - A Midwest USA perspective (United States)

    C. H. Michler; R. Meilan; K. E. Woeste; P. M. Pijut; D. Jacobs; P. Aldrich; J. Glaubitz


    Fine hardwood trees in the Central Hardwoods region of the United States are an important resource for the furniture, cabinetry, flooring, modular home, and paneling manufacturing industries. Consumers find wood from these trees to be very desirable because of quality factors such as grain, strength and color. To enhance wood production, tree improvement programs can...

  19. Market Definition For Hardwood Timber in the Southern Appalachians (United States)

    Jeffrey P. Prestemon; John M. Pye; Karen Lee Abt; David N. Wear


    Direct estimation of aggregate hardwood supply is seriously complicated by the diversity of prices, species, and site conditions in hardwood stands. An alternative approach is to aggregate regional supply based on stumpage values of individual stands, arguably the real driver of harvest decisions. Complicating this approach is that species-specific prices are only...

  20. Central Hardwoods ecosystem vulnerability assessment and synthesis: a report from the Central Hardwoods Climate Change Response Framework project (United States)

    Leslie Brandt; Hong He; Louis Iverson; Frank R. Thompson; Patricia Butler; Stephen Handler; Maria Janowiak; P. Danielle Shannon; Chris Swanston; Matthew Albrecht; Richard Blume-Weaver; Paul Deizman; John DePuy; William D. Dijak; Gary Dinkel; Songlin Fei; D. Todd Jones-Farrand; Michael Leahy; Stephen Matthews; Paul Nelson; Brad Oberle; Judi Perez; Matthew Peters; Anantha Prasad; Jeffrey E. Schneiderman; John Shuey; Adam B. Smith; Charles Studyvin; John M. Tirpak; Jeffery W. Walk; Wen J. Wang; Laura Watts; Dale Weigel; Steve. Westin


    The forests in the Central Hardwoods Region will be affected directly and indirectly by a changing climate over the next 100 years. This assessment evaluates the vulnerability of terrestrial ecosystems in the Central Hardwoods Region of Illinois, Indiana, and Missouri to a range of future climates. Information on current forest conditions, observed climate trends,...

  1. Soil properties in 35 y old pine and hardwood plantations after conversion from mixed pine-hardwood forest (United States)

    D. Andrew Scott; Michael G. Messina


    Past management practices have changed much of the native mixed pine-hardwood forests on upland alluvial terraces of the western Gulf Coastal Plain to either pine monocultures or hardwood (angiosperm) stands. Changes in dominant tree species can alter soil chemical, biological, and physical properties and processes, thereby changing soil attributes, and ultimately,...

  2. Planting and care of fine hardwood seedlings: diseases in hardwood tree plantings (United States)

    Paula M. Pijut


    Hardwood trees planted for timber production, wildlife habitat, riparian buffers, native woodland restoration, windbreaks, watershed protection, erosion control, and conservation are susceptible to damage or even death by various native and exotic fungal or bacterial diseases. Establishment, growth, and the quality of the trees produced can be affected by these disease...

  3. 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


    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.

  4. 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


    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.

  5. Interactions of Kraft lignin and wheat gluten during biomaterial processing: evidence for the role of phenolic groups. (United States)

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


    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.

  6. 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


    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

  7. 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)


    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)

  8. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S


    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)



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


    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. ...

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

    Directory of Open Access Journals (Sweden)

    Roseli Garcia Medeiros


    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

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

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander


    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...

  12. Synergy of agroforestry and bottomland hardwood afforestation (United States)

    Twedt, D.J.; Portwood, J.; Clason, Terry R.


    Afforestation of bottomland hardwood forests has historically emphasized planting heavy-seeded tree species such as oak (Quercus spp.) and pecan (Caryaillinoensis) with little or no silvicultural management during stand development. Slow growth of these tree species, herbivory, competing vegetation, and limited seed dispersal, often result in restored sites that are slow to develop vertical vegetation structure and have limited tree diversity. Where soils and hydrology permit, agroforestry can provide transitional management that mitigates these historical limitations on converting cropland to forests. Planting short-rotation woody crops and intercropping using wide alleyways are two agroforestry practices that are well suited for transitional management. Weed control associated with agroforestry systems benefits planted trees by reducing competition. The resultant decrease in herbaceous cover suppresses small mammal populations and associated herbivory of trees and seeds. As a result, rapid vertical growth is possible that can 'train' under-planted, slower-growing, species and provide favorable environmental conditions for naturally invading trees. Finally, annual cropping of alleyways or rotational pulpwood harvest of woody crops provides income more rapidly than reliance on future revenue from traditional silviculture. Because of increased forest diversity, enhanced growth and development, and improved economic returns, we believe that using agroforestry as a transitional management strategy during afforestation provides greater benefits to landowners and to the environment than does traditional bottomland hardwood afforestation.

  13. Technical Report Cellulosic Based Black Liquor Gasification and Fuels Plant Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Fornetti, Micheal [Escanaba Paper Company, MI (United States); Freeman, Douglas [Escanaba Paper Company, MI (United States)


    The Cellulosic Based Black Liquor Gasification and Fuels Plant Project was developed to construct a black liquor to Methanol biorefinery in Escanaba, Michigan. The biorefinery was to be co-located at the existing pulp and paper mill, NewPage’s Escanaba Paper Mill and when in full operation would: • Generate renewable energy for Escanaba Paper Mill • Produce Methanol for transportation fuel of further refinement to Dimethyl Ether • Convert black liquor to white liquor for pulping. Black liquor is a byproduct of the pulping process and as such is generated from abundant and renewable lignocellulosic biomass. The biorefinery would serve to validate the thermochemical pathway and economic models for black liquor gasification. It was a project goal to create a compelling new business model for the pulp and paper industry, and support the nation’s goal for increasing renewable fuels production and reducing its dependence on foreign oil. NewPage Corporation planned to replicate this facility at other NewPage Corporation mills after this first demonstration scale plant was operational and had proven technical and economic feasibility. An overview of the process begins with black liquor being generated in a traditional Kraft pulping process. The black liquor would then be gasified to produce synthesis gas, sodium carbonate and hydrogen sulfide. The synthesis gas is then cleaned with hydrogen sulfide and carbon dioxide removed, and fed into a Methanol reactor where the liquid product is made. The hydrogen sulfide is converted into polysulfide for use in the Kraft pulping process. Polysulfide is a known additive to the Kraft process that increases pulp yield. The sodium carbonate salts are converted to caustic soda in a traditional recausticizing process. The caustic soda is then part of the white liquor that is used in the Kraft pulping process. Cellulosic Based Black Liquor Gasification and Fuels Plant project set out to prove that black liquor gasification could

  14. Black bark as an indicator of bird peck defect in sugar maple (United States)

    John H. Ohman; K.J., Jr. Kessler


    Portions of the lower bole of occasional sugar maples (Acer saccharum Marsh.) in Lake States northern hardwood stands are sooty black in sharp contrast to the normal gray. The blackened areas may encircle the entire stem or be confined to a narrow band; they have been observed as high as 25 feet but generally extend about 15 feet above the ground....

  15. Epicormic branching of California black oak: effect of stand and tree characteristics (United States)

    Philip M. McDonald; Martin W. Ritchie


    Young California black oak (Quercus kelloggii Newb.) stands usually require thinning to increase production of acorns and wood products, but epicormic branches, which yield no acorns and constitute a serious lumber degrade. often result. A crown thinning in 60-year-old hardwood stands on a south exposure at the Challenge Experimental Forest in thenorthern Sierra Nevada...

  16. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.


    This article deals with two questions, namely whether it is possible for black holes to exist, and if the answer is yes, whether we have found any yet. In deciding whether black holes can exist or not the central role in the shaping of our universe played by the forse of gravity is discussed, and in deciding whether we are likely to find black holes in the universe the author looks at the way stars evolve, as well as white dwarfs and neutron stars. He also discusses the problem how to detect a black hole, possible black holes, a southern black hole, massive black holes, as well as why black holes are studied

  17. Vegetative Propagation and the Genetic Improvement of North American Hardwoods (United States)

    R. E. Farmer


    Progress and problems in vegetative propagation of important North American hardwoods are reviewed with emphasis on rooting cuttings and the application of propagation techniques in breeding research. Some problems in rooting physiology are discussed.

  18. How second-growth northern hardwoods develop after thinning (United States)

    Robert W., Jr. Wilson


    In the northern hardwood region, second-growth stands occupy thousands of acres. These stands are of all ages, in all conditions. They were brought about by fire, charcoal and fuelwood cuttings, land abandonment, or a combination of these causes.

  19. Two eras of globalization and hardwood sawtimber demand (United States)

    William G. Luppold; Matthew S. Bumgardner


    In the early 1970s, the adoption of floating exchange rates resulted in more fluid transfers between international currencies and spurred increased international demand for hardwood lumber produced in the United States.

  20. 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


    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.

  1. 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)


    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)

  2. 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


    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

  3. 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.


    Directory of Open Access Journals (Sweden)

    Danila Morais de Carvalho


    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.

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

    Directory of Open Access Journals (Sweden)

    L. B. Tavares


    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.

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

    Directory of Open Access Journals (Sweden)

    M. M. Costa


    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.

  7. Membrane treatment of alkaline bleaching effluents from elementary chlorine free kraft softwood cellulose production. (United States)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ziemba, G.


    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.)

  9. Black Alcoholism. (United States)

    Watts, Thomas D.; Wright, Roosevelt


    Examines some aspects of the problem of alcoholism among Blacks, asserting that Black alcoholism can best be considered in an ecological, environmental, sociocultural, and public health context. Notes need for further research on alcoholism among Blacks and for action to reduce the problem of Black alcoholism. (NB)

  10. Black holes


    Brügmann, B.; Ghez, A. M.; Greiner, J.


    Recent progress in black hole research is illustrated by three examples. We discuss the observational challenges that were met to show that a supermassive black hole exists at the center of our galaxy. Stellar-size black holes have been studied in x-ray binaries and microquasars. Finally, numerical simulations have become possible for the merger of black hole binaries.

  11. The Wood and Bark of Hardwoods Growing on Southern Pine Sites - A Pictorial Atlas (United States)

    Charles W. McMillin; Floyd G. Manwiller


    Provides a pictorial description of the structure and appearance of 23 pine-site hardwoods, an overview of hardwood anatomy, and data on the resource and certain important physical properties of stemwood and bark.

  12. Examination of worldwide hardwood lumber production, trade, and apparent consumption: 1995-2013 (United States)

    William G. Luppold; Matthew S. Bumgardner


    Worldwide hardwood lumber production fluctuated between 1995 and 2013 and changed considerably with respect to regional market shares. Similarly, worldwide hardwood lumber imports and exports have been constantly changing. Understanding these changes is important because collectively, they define the hardwood lumber consumption of a region or country. In 1995, North...

  13. Decision Criteria for German Hardwood Lumber Buyers: Market Needs and Purchase (United States)

    Thomas G. Ponzurick; Robert J. Bush; Dieter Schaupp; Philip A. Araman


    The purpose of this study was to develop a better understanding of hardwood exports to the German market. A mail survey was conducted which resulted in a 47.8 percent rate of response. Of those German hardwood buyers responding to the survey, 71 percent purchased hardwood lumber directly from North America.

  14. Impacts of changing hardwood lumber consumption and price on stumpage and sawlog prices in Ohio (United States)

    William Luppold; Matthew Bumgardner; T. Eric. McConnell


    In the early 2000s, increasing US furniture imports preceded declining US hardwood lumber demand and price. In the summer of 2002, however, hardwood lumber prices started to increase as demand by construction industries increased. By the mid-2000s, hardwood lumber prices hit all-time highs. Lumber prices hit all-time highs for red oak (Quercus spp...

  15. Marketing low-grade hardwoods for furniture stock - a new approach (United States)

    Hugh W. Reynolds; Charles J. Gatchell


    A hardwood shortage of high-grade lumber exists while there is a surplus of low-grade hardwood timber. Two things are needed for the surplus to correct the shortage: a new manufacturing system and a new marketing technique. Utilization research at the Princeton Forestry Sciences Laboratory has developed the new system for converting low-grade hardwood for furniture use...

  16. The changing structure of the hardwood lumber industry with implications on technology adaptation (United States)

    William Luppold; John Baumgras; John Baumgras


    The hardwood sawmilling industry has been changing over the last 50 years as a result of changes in hardwood sawtimber inventory and in the demand for hardwood lumber. In 1950 the industry was composed of numerous individual mills, few of which produced more than 3 million board feet of lumber annually. During this time the furniture industry was the major user of...

  17. Genetic improvement of hardwood fiber production in the north-central region: potentials and breeding alternatives (United States)

    R.E., Jr. Farmer


    In the Lake States, aspens are now growing towards senility Faster than they are being harvested (Groff 1966). In the Central States, wood processing residues have recently supplied about one-half of the area's hardwood fiber requirement (Blyth 1970), thus allowing hardwood growing stock to continue its recuperation. In fact, the national hardwood fiber supply...

  18. Database for estimating tree responses of walnut and other hardwoods to ground cover management practices (United States)

    J.W. Van Sambeek


    The ground cover in plantings of walnut and other hardwoods can substantially affect tree growth and seed production. The number of alternative ground covers that have been suggested for establishment in tree plantings far exceeds the number that have already been tested with walnut and other temperate hardwoods. Knowing how other hardwood species respond to ground...

  19. A Comparison of Market Needs to the Species and Quality Composition of the Eastern Hardwood (United States)

    Robert J. Bush; Philip A. Araman


    Many markets for hardwood lumber have experienced growth in recent years. Eastern and Central hardwood lumber production reached an estimated 11.2 billion board feet in 1988, a twenty year high. Wood furniture, flooring, and exports have also experienced growth in the last ten years. During the same period, annual growth on eastern hardwood forests has exceeded annual...

  20. Technological advances in temperate hardwood tree improvement including breeding and molecular marker applications (United States)

    Paula M. Pijut; Keith E. Woeste; G. Vengadesan


    Hardwood forests and plantations are an important economic resource for the forest products industry worldwide and to the international trade of lumber and logs. Hardwood trees are also planted for ecological reasons, for example, wildlife habitat, native woodland restoration, and riparian buffers. The demand for quality hardwood from tree plantations will continue to...

  1. 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...

  2. 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)


    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.)

  3. Fractionation and cellulase treatment for enhancing the properties of kraft-based dissolving pulp. (United States)

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


    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.

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

    International Nuclear Information System (INIS)

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


    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)

  5. Process for purification of waste water produced by a Kraft process pulp and paper mill (United States)

    Humphrey, M. F. (Inventor)


    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.

  6. 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


    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...

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

    International Nuclear Information System (INIS)

    Hamzeh, Y.; Izadyar, S.


    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

  8. 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.


    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.

  9. Factors influencing changes in U.S. hardwood log and lumber exports from 1990 to 2011. BioResources (United States)

    William G. Luppold; Matthew S. Bumgardner


    Domestic consumption of hardwood products in the United States since 2000 has trended downward, making exports the single most important market for higher grade hardwood lumber and a major market for higher value hardwood logs. Between 1990 and 2011, hardwood lumber exports increased by 46%. During most of this period, Canada was the largest export market for U.S....

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)


    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)

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

    International Nuclear Information System (INIS)

    Li, Dongbing; Briens, Cedric; Berruti, Franco


    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

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

    Directory of Open Access Journals (Sweden)

    Gladys Vidal


    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.

  14. 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


    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

  15. Black Tea (United States)

    ... mental alertness as well as learning, memory, and information processing skills. It is also used for treating headache; ... of carbamazepine. Since black tea contains caffeine, in theory taking black tea with carbamazepine might decrease the ...

  16. Response to crop-tree release by 7-year-old stems of yellow-poplar and black cherry (United States)

    G.R. Jr. Trimble; G.R. Jr. Trimble


    Five years after crop-tree release of yellow-poplar and black cherry sterns in a 7-year-old stand of Appalachian hardwoods, measurements indicated that released trees were but slightly superior to control trees in height, diameter, and crown position. Sprout regrowth of cut tree stems and grapevines had largely nullified the effects of release. Indications are that for...

  17. Black Holes


    Townsend, P. K.


    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usu...

  18. 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)


    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)

  19. Proceedings of the black liquor research program review fifth meeting

    Energy Technology Data Exchange (ETDEWEB)


    On June 14--17, 1988 the participants and invited guests of the Cooperative Program in Kraft Recovery gathered in Charleston, South Carolina, to review progress on four major black liquor research programs being executed at the Institute of Paper Chemistry, the University of Maine, the National Bureau of Standards, and the University of Florida. These programs include: (1) Black Liquor Properties; (2) Black Liquor Droplet Formation; (3) Black Liquor Nozzle Evaluation; and (4) Black Liquor Combustion. In addition to the objectives of previous meetings, this meeting made a direct attempt to gather ideas on how to improve our ability to move from new technology concepts to commercial implementation. Also attached is the agenda for the Charleston meeting. The first two days were involved with updates and reviews of the four major black liquor programs. A half day was spent discussing pathways to implementation and developing thoughts on what industry, DOE and academia could do to facilitate commercial implementation of the research results. This publication is a summary of the presentations made in Charleston and the industry responses to the research work. Readers are cautioned that the contents are in-progress updates on the status of the research and do not represent referred technical papers. Any questions regarding the content should be referred to the principal investigators of the project.

  20. Black Holes


    Horowitz, Gary T.; Teukolsky, Saul A.


    Black holes are among the most intriguing objects in modern physics. Their influence ranges from powering quasars and other active galactic nuclei, to providing key insights into quantum gravity. We review the observational evidence for black holes, and briefly discuss some of their properties. We also describe some recent developments involving cosmic censorship and the statistical origin of black hole entropy.





    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...

  2. Inter-laboratory comparisons of hexenuronic acid measurements in kraft eucalyptus pulps using a UV-Vis spectroscopic method (United States)

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


    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...

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

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


    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

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


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


    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...

  5. 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


    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.

  6. 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


    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.

  7. Experimental Studies on the Hydrotreatment of Kraft Lignin to Aromatics and Alkylphenolics Using Economically Viable Fe-Based Catalysts (United States)


    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


    Directory of Open Access Journals (Sweden)

    André Fredo


    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.

  9. Automatic scanning of rough hardwood lumber for edging and trimming (United States)

    A. Lynn Abbott; Daniel L. Schmoldt; Philip A. Araman; Sang-Mook Lee


    Scanning of unplaned, green hardwood lumber has received relatively little attention in the research community. This has been due in part to the difficulty of clearly imaging fresh-cut boards whose fibrous surfaces mask many wood features. Nevertheless, it is important to improve lumber processing early in the manufacturing stream because much wood material is...

  10. A Machine Vision System for Automatically Grading Hardwood Lumber - (Proceedings) (United States)

    Richard W. Conners; Tai-Hoon Cho; Chong T. Ng; Thomas H. Drayer; Joe G. Tront; Philip A. Araman; Robert L. Brisbon


    Any automatic system for grading hardwood lumber can conceptually be divided into two components. One of these is a machine vision system for locating and identifying grading defects. The other is an automatic grading program that accepts as input the output of the machine vision system and, based on these data, determines the grade of a board. The progress that has...

  11. A logging residue "yield" table for Appalachian hardwoods (United States)

    A. Jeff Martin


    An equation for predicting logging-residue volume per acre for Appalachian hardwoods was developed from data collected on 20 timber sales in national forests in West Virginia and Virginia. The independent variables of type-of-cut, products removed, basal area per acre, and stand age explained 95 percent of the variation in residue volume per acre. A "yield"...

  12. Taper and volume equations for selected Appalachian hardwood species (United States)

    A. Jeff Martin


    Coefficients for five taper/volume models are developed for 18 Appalachian hardwood species. Each model can be used to estimate diameter at any point on the bole, height to any preselected diameter, and cubic-foot volume between any two points on the bole. The resulting equations were tested on six sets of independent data and an evaluation of these tests is included,...

  13. Computer Vision Systems for Hardwood Logs and Lumber (United States)

    Philip A. Araman; Tai-Hoon Cho; D. Zhu; R. Conners


    Computer vision systems being developed at Virginia Tech University with the support and cooperation from the U.S. Forest Service are presented. Researchers at Michigan State University, West Virginia University, and Mississippi State University are also members of the research team working on various parts of this research. Our goals are to help U.S. hardwood...

  14. Field testing a soil site field guide for Allegheny hardwoods (United States)

    S.B. Jones


    A site quality evaluation decision model, developed for Allegheny hardwoods on the non-glaciated Allegheny Plateau of Pennsylvania and New York, was field tested by International Paper (IP) foresters and the author, on sites within the region of derivation and on glaciated sites north and west of the Wisconsin drift line. Results from the field testing are presented...

  15. Western hardwoods : value-added research and demonstration program (United States)

    D. W. Green; W. W. Von Segen; S. A. Willits


    Research results from the value-added research and demonstration program for western hardwoods are summarized in this report. The intent of the program was to enhance the economy of the Pacific Northwest by helping local communities and forest industries produce wood products more efficiently. Emphasis was given to value-added products and barriers to increased...

  16. Regional analysis of hardwood lumber production: 1963 - 2005 (United States)

    William Luppold; Matthew Bumgardner


    Between 1963 and 2005 hardwood lumber production in the eastern United States increased by more than 50%. Production more than doubled in the northeastern and north central regions while increasing by less than 25% in the southeastern and south central regions. Increased lumber production in the northern regions was facilitated by an expanding sawtimber inventory,...

  17. The economic potential of CT scanners for hardwood sawmills (United States)

    Donald G. Hodges; Walter C. Anderson; Charles W. McMillin


    Research has demonstrated that a knowledge of internal log defects prior to sawing could improve lumber value yields significantly. This study evaluated the potential economic returns from investments in computerized tomographic (CT) scanners to detect internal defects in hardwood logs at southern sawmills. The results indicate that such investments would be profitable...

  18. Guide to wildlife tree management in New England northern hardwoods (United States)

    Carl H. Tubbs; Richard M. DeGraaf; Mariko Yamasaki; William M. Healy


    Presents information on the culture and management of trees that have value as components of wildlife habitat in the northern hardwood and associated types in New England. Background information is provided for choosing the most suitable trees for wildlife habitats and for estimat ing the impact of timber production. Suggestions are made for choosing the numbers of...

  19. Decay fungi of oaks and associated hardwoods for western arborists (United States)

    Jessie A. Glaeser; Kevin T. Smith


    Examination of trees for the presence and extent of decay should be part of any hazard tree assessment. Identification of the fungi responsible for the decay improves prediction of tree performance and the quality of management decisions, including tree pruning or removal. Scouting for Sudden Oak Death (SOD) in the West has drawn attention to hardwood tree species,...

  20. Pennsylvania hardwood timber bridges : field performance after 10 years (United States)

    James P. Wacker; Carlito Calil


    Several hardwood demonstration timber bridges were built by the Pennsylvania Department of Transportation in the early nineteen nineties. These bridge superstructures are of the recently developed stress-laminated deck design-type using Red Oak lumber laminations that were pressure-treated with creosote preservatives. This paper will describe the data acquisition...

  1. Central hardwood forests: recent trends in a robust resource (United States)

    T. W. Birch; D. A. Gansner; W. H. McWilliams


    Re-inventories completed for each of four Central Hardwood States (Kentucky, Ohio, Pennsylvania, and West Virginia) show that forest area is increasing and stocking hit new highs; there is 27 percent more growing-stock volume than a decade ago. Large increases in volume have been recorded for all but the smallest diameter classes. Volume in trees 15 inches in diameter...

  2. Testing and analysis of internal hardwood log defect prediction models (United States)

    R. Edward Thomas


    The severity and location of internal defects determine the quality and value of lumber sawn from hardwood logs. Models have been developed to predict the size and position of internal defects based on external defect indicator measurements. These models were shown to predict approximately 80% of all internal knots based on external knot indicators. However, the size...

  3. A whole stand basal area projection model for Appalachian hardwoods (United States)

    John R. Brooks; Lichun Jiang; Matthew Perkowski; Benktesh Sharma


    Two whole-stand basal area projection models were developed for Appalachian hardwood stands. The proposed equations are an algebraic difference projection form based on existing basal area and the change in age, trees per acre, and/or dominant height. Average equation error was less than 10 square feet per acre and residuals exhibited no irregular trends.

  4. Production economics of harvesting young hardwood stands in central Appalachia (United States)

    Yaoxiang Li; Jingxin Wang; Gary W. Miller; Joe McNeel


    Three harvesting systems of chainsaw/cable skidder, fell-buncher/grapple skidder, and harvester/forwarder were simulated in harvesting three hardwood stands of 30 to 50 years old in central Appalachia. Stands were generated by using a stand generator and harvesting prescriptions included clearcut, shelterwood cut, selective cut, diameter limit cut, and crop tree...

  5. A 3D stand generator for central Appalachian hardwood forests (United States)

    Jingxin Wang; Yaoxiang Li; Gary W. Miller


    A 3-dimensional (3D) stand generator was developed for central Appalachian hardwood forests. It was designed for a harvesting simulator to examine the interactions of stand, harvest, and machine. The Component Object Model (COM) was used to design and implement the program. Input to the generator includes species composition, stand density, and spatial pattern. Output...

  6. Quality index tables for some eastern hardwood species (United States)

    Joseph J. Mendel; William H. Smith; William H. Smith


    This paper briefly reviews the quality-index concept, presents log-quality index tables for a selected group of eastern hardwood tree species, and explains how timber operators can use Q.I. for evaluating the lumber that can be sawed from logs and trees.

  7. Current status of the U.S. hardwood industry (United States)

    Urs Buehlmann; Matthew Bumgardner; Michael. Sperber


    The U.S. manufacturing sector has seen challenging years during the past decades. The major driver behind the decline of U.S. manufacturing prowess has been the ongoing globalization of trade, which has brought market share losses for U.S.-based manufacturing in many hardwood lumber consuming industries. The wood furniture, flooring, and millwork industries, for...

  8. An investigation of factors affecting wettability of some southern hardwoods (United States)

    Todd F. Shupe; Chung Y. Hse; Wan H. Wang


    >Wettability of sanded and nonsanded transverse and tangential sections of 22 southern hardwood species were[was] judged by measurement of contact angles using phenol-formaldehyde resins. As ex­pected, contact angle values on transverse sec­tions were higher than on tangential sections for both sanded and...

  9. An investigation of selected factors that influence hardwood wettability (United States)

    Todd F. Shupe; Chung-Yun Hse; Wan H. Wang


    Wettability of sanded and non-sanded transverse and tangential sections of 22 southern hardwoods species was judged by measurement of contact angles using phenol formaldehyde resins. As expected, contact angle values on transverse sections were higher than those on tangential sections for both sanded and non-sanded surfaces. On sanded surfaces, hackberry had the...

  10. 78 FR 76857 - Hardwood Plywood From China; Determinations (United States)


    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-490 and 731-TA-1204 (Final)] Hardwood..., the United States International Trade Commission (Commission) determines, pursuant to sections 705(b.... International Trade Commission, Washington, DC, and by publishing the notice in the Federal Register on June 19...

  11. An Old-Growth Definition for Southern Mixed Hardwood Forests (United States)

    William B. Batista; William J. Platt


    This report provides an old-growth definition for the southern mixed hardwood forests based on five exemplary stands that show no evidence of having undergone any natural catastrophe or clearcutting for at least 200 years. This forest type occurs in the U.S. southeastern Coastal Plain from the Carolinas to eastern Texas. The exemplary old-growth stands were restricted...

  12. Resistance of eastern hardwood stems to fire injury and damage (United States)

    Kevin T. Smith; Elaine Kennedy Sutherland


    This paper reviews the protective features and defensive responses of eastern hardwood species exposed to fire. Trees survive fire through protective features such as thick bark and the induced defenses of compartmentalization. Dissection of trees exposed to prescribed fire in an oak forest in southern Ohio highlights the need to distinguish between bark scorch, stem...

  13. Seasonal influence on Ohio hardwood stumpage price trends (United States)

    T. Eric. McConnell


    The average annual percentage rates of change in real sawtimber stumpage prices from 1978 through 2012 (dollars per thousand board feet, Doyle) for the 10 commercial hardwood species of Ohio were determined. Each species was then further examined for differing trend lines between the spring and fall reporting periods. Annual real rates of change ranged from -1.10...

  14. Validation of an internal hardwood log defect prediction model (United States)

    R. Edward. Thomas


    The type, size, and location of internal defects dictate the grade and value of lumber sawn from hardwood logs. However, acquiring internal defect knowledge with x-ray/computed-tomography or magnetic-resonance imaging technology can be expensive both in time and cost. An alternative approach uses prediction models based on correlations among external defect indicators...

  15. Competition and climate affects US hardwood-forest tree mortality (United States)

    Daniel A. Yaussy; Louis R. Iverson; Stephen N. Matthews


    Individual-tree measurements have been collected periodically on sites established in Kentucky, New York, Ohio, and Pennsylvania to investigate the effects of thinning on the growth and yield of valuable hardwood species. These plots were installed between 1959 and 1985. The long-term characteristics of this data set of 47,853 trees allowed us to investigate potential...

  16. Comparison of Germination and Viability Tests for Southern Hardwood Seed (United States)

    F. T. Bonner; J. L. Gammage


    This paper summarizes a 3-year evaluation of 10 methods for testing germinability and viability of the seed of six species of southern hardwood. In five of the methods, the seeds were germinated. In the others, visual, biochemical, or physical properties were the criteria. Cutting tests were best for sweetgum and Nuttall oak seed, while cutting or water germination...

  17. Machine Vision Systems for Processing Hardwood Lumber and Logs (United States)

    Philip A. Araman; Daniel L. Schmoldt; Tai-Hoon Cho; Dongping Zhu; Richard W. Conners; D. Earl Kline


    Machine vision and automated processing systems are under development at Virginia Tech University with support and cooperation from the USDA Forest Service. Our goals are to help U.S. hardwood producers automate, reduce costs, increase product volume and value recovery, and market higher value, more accurately graded and described products. Any vision system is...

  18. Influence of Lumber Volume Maximization in Sawing Hardwood Sawlogs (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman


    The Best Opening Face (BOF) technology for volume maximization during sawing has been rapidly adopted by softwood sawmills. Application of this technology in hardwood sawmills has been limited because of their emphasis on sawing for the highest possible grade of lumber. The reason for this emphasis is that there is a relatively large difference in price between the...

  19. Software analyzes feasibility of saw kerf reduction for hardwood mills (United States)

    Philip H. Steele


    Reductions in saw kerf on head rigs and resaws can dramatically increase lumber recovery in hardwood sawmills. Research has shown that lumber sawing variation reduction will increase lumber recovery above that obtained solely from kerf reduction. Reductions in sawing machine kerf or variation always come at some cost in both capital and variable costs. Determining...

  20. Interactive machine learning for postprocessing CT images of hardwood logs (United States)

    Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt


    This paper concerns the nondestructive evaluation of hardwood logs through the analysis of computed tomography (CT) images. Several studies have shown that the commercial value of resulting boards can be increased substantially if log sawing strategies are chosen using prior knowledge of internal log defects. Although CT imaging offers a potential means of obtaining...

  1. Upland hardwood habitat types in southwestern North Dakota (United States)

    Michele M. Girard; Harold Goetz; Ardell J. Bjugstad


    The Daubenmire habitat type method was used to classify the upland hardwood draws of southwestern North Dakota. Preliminary data analysis indicates there are four upland habitat types: Fraxinus pennsylvanica/Prunus virginiana; F. pnnseanica-Ulmus americana/P. virginiana; Populus...

  2. Edge-glued panels from Alaska hardwoods: retail manager perspectives (United States)

    David Nicholls; Matthew Bumgardner; Valerie Barber


    In Alaska, red alder (Alnus rubra Bong.) and paper birch (Betula papyrifera Marsh.) are both lesser-known hardwoods grown, harvested, and manufactured into appearance products, with potential for increased utilization. The production of edgeglued panels from red alder and paper birch offers one expansion opportunity for wood...

  3. Reproduction of upland hardwood forests in the central states (United States)

    Ivan L. Sander; F. Bryan Clark


    This handbook summarizes data from studies of central hardwood reproduction after harvest cuttings ranging from single-tree selection cutting to complete clearcutting. Regardless of how the stands were cut, natural reproduction was always adequate to produce acceptable new stands; but the heavier cuttings favored intolerant species and faster growth of all species....

  4. Growth and Survival of Northern Hardwood Sprouts After Burning (United States)

    Donald A. Perala


    Root collar sprouting of nine hardwoods was measured annually after a prescribed burn. Basswood, red oak, and paper birch were the most vigorous sprouters; sugar maple and yellow birch the least; and American elm, bur oak, ironwood and red maple were intermediate. Parent tree diameter influenced spreading.

  5. Indicators of regenerative capacity for eastern hardwood forests (United States)

    William H. McWilliams; Todd W. Bowersox; Patrick H. Brose; Daniel A. Devlin; James C. Finley; Steve Horsley; Kurt W. Gottschalk; Tonya W. Lister; Larry H. McCormick; Gary W. Miller; Kim C. Steiner; Susan L. Stout; James A. Westfall; Robert L. White


    Hardwood forests of the eastern United States are characterized by a complex mix of species associations that make it difficult to construct useful indicators of long-term sustainability, in terms of future forest composition and stocking levels. The Pennsylvania Regeneration Study examines regeneration adequacy in the state. The study uses the Forest Service's...

  6. A procedure for selection on marking in hardwoods (United States)

    George R., Jr. Trimble; Joseph J. Mendel; Richard A. Kennell


    This method of applying individual-tree selection silviculture to hardwood stands combines silvicultural considerations with financial maturity guidelines into a tree-marking system. To develop this system it was necessary to determine rates of return based on 4/4 lumber, for many of the important Appalachian species. Trees were viewed as capital investments that...

  7. Private forest owners of the Central Hardwood Forest (United States)

    Thomas W. Birch


    A recently completed survey of woodland owners provides insight into the owners of private forest lands in the Central Hardwood Region. There is increasing parcelization of forested lands and an increase in the numbers of nonindustrial private forest-land owners. Over half of the private owners have harvested timber from their holdings at some time in the past, they...

  8. Chapter 4:Grading and properties of hardwood structural lumber (United States)

    David W. Green


    Structural lumber markets have traditionally been dominated by softwood species. Historically, however, hardwood species have been extensively used for certain structural products such as timbers for railway and highway bridges, railway ties, mine timbers, and for pallets and containers. In the 1920s, when uniform procedures were first developed for structural grading...

  9. Fire in Eastern Hardwood Forests through 14,000 Years (United States)

    Martin A. Spetich; Roger W. Perry; Craig A. Harper; Stacy L. Clark


    Fire helped shape the structure and species composition of hardwood forests of the eastern United States over the past 14,000 years. Periodic fires were common in much of this area prior to European settlement, and fire-resilient species proliferated. Early European settlers commonly adopted Native American techniques of applying fire to the landscape. As the demand...

  10. Economic considerations of uneven-age hardwood management (United States)

    H. Clay Smith; Gary W. Miller


    Uneven-age management or partial cutting methods as described in this paper allow foresters to manage eastern hardwood stands and harvest forest products without clearcutting. These methods can involve regular periodic harvests, at least for the short term, based on stand conditions and growing-site capabilities. We are not going to make the decision as to which is the...

  11. A century of progress in weed control in hardwood seedbeds (United States)

    David B. South


    Weeds have existed in nurseries since before the time Bartram grew hardwoods during the 18th century. Hand weeding was the primary method of weed control during the first part of the 20th century. From 1931 to 1970, advances in chemistry increased the use of herbicides, and advances in engineering increased the reliance on machines for cultivation. Many managers now...

  12. A Multiple Sensor Machine Vision System Technology for the Hardwood (United States)

    Richard W. Conners; D.Earl Kline; Philip A. Araman


    For the last few years the authors have been extolling the virtues of a multiple sensor approach to hardwood defect detection. Since 1989 the authors have actively been trying to develop such a system. This paper details some of the successes and failures that have been experienced to date. It also discusses what remains to be done and gives time lines for the...

  13. Sawtooth forces in cutting tropical hardwoods native to South America (United States)

    S. P. Loehnertz; I. V. Cooz

    As a result of design, operation, and maintenance, sawblades used in tropical sawmills can cause many problems. Improvements in these areas are needed to reduce the waste associated with sawing of tropical species that are regarded as difficult to cut. In this study, cutting experiments that simulated bandsawing of tropical hardwoods showed the effect of chip...

  14. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown


    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life.

  15. Mill Integration-Pulping, Stream Reforming and Direct Causticization for Black Liquor Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Adriaan van Heiningen


    MTCI/StoneChem developed a steam reforming, fluidized bed gasification technology for biomass. DOE supported the demonstration of this technology for gasification of spent wood pulping liquor (or 'black liquor') at Georgia-Pacific's Big Island, Virginia mill. The present pre-commercial R&D project addressed the opportunities as well as identified negative aspects when the MTCI/StoneChem gasification technology is integrated in a pulp mill production facility. The opportunities arise because black liquor gasification produces sulfur (as H{sub 2}S) and sodium (as Na{sub 2}CO{sub 3}) in separate streams which may be used beneficially for improved pulp yield and properties. The negative aspect of kraft black liquor gasification is that the amount of Na{sub 2}CO{sub 3} which must be converted to NaOH (the so called causticizing requirement) is increased. This arises because sulfur is released as Na{sub 2}S during conventional kraft black liquor recovery, while during gasification the sodium associated Na{sub 2}S is partly or fully converted to Na{sub 2}CO{sub 3}. The causticizing requirement can be eliminated by including a TiO{sub 2} based cyclic process called direct causticization. In this process black liquor is gasified in the presence of (low sodium content) titanates which convert Na{sub 2}CO{sub 3} to (high sodium content) titanates. NaOH is formed when contacting the latter titanates with water, thereby eliminating the causticizing requirement entirely. The leached and low sodium titanates are returned to the gasification process. The project team comprised the University of Maine (UM), North Carolina State University (NCSU) and MTCI/ThermoChem. NCSU and MTCI are subcontractors to UM. The principal organization for the contract is UM. NCSU investigated the techno-economics of using advanced pulping techniques which fully utilize the unique cooking liquors produced by steam reforming of black liquor (Task 1). UM studied the kinetics and

  16. Carbon Nanostructure of Kraft Lignin Thermally Treated at 500 to 1000 °C. (United States)

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


    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.

  17. Structural, morphological, and thermal characterization of kraft lignin and its charcoals obtained at different heating rates (United States)

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


    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.

  18. Acid-catalysed xylose dehydration into furfural in the presence of kraft lignin. (United States)

    Lamminpää, Kaisa; Ahola, Juha; Tanskanen, Juha


    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.

  19. Effect of depth beating on the fiber properties and enzymatic saccharification efficiency of softwood kraft pulp. (United States)

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


    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.

  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))


    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


    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. (United States)

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


    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. (United States)

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


    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


    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. Development of radiation processes wood-polymer composites based on tropical hardwoods

    International Nuclear Information System (INIS)

    Iya, V.K.; Majali, A.B.


    The wood-polymer composites based on tropical hardwoods were prepared with three monomer systems. Use of chlorinated paraffin oil as an additive imparted fire resistance to the composites and also brought down the gamma dose requirement for total polymerisation. A number of tropical hardwoods can be upgraded by radiation curing, but for cost optimisation, hardwoods with high improvement per unit polymer should be selected. (author)

  6. 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.


    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.

  7. Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

    DEFF Research Database (Denmark)

    Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette


    A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... profiles) and molecular (β-tubulin, internal transcribed spacer and calmodulin gene sequences, and universally primed PCR fingerprinting) analysis. Phenotypic and molecular data enabled this novel species to be clearly distinguished from other black aspergilli. A. saccharolyticus is a uniseriate...

  8. Influence of pressure on pyrolysis of black liquor: 1. Swelling. (United States)

    Whitty, Kevin; Backman, Rainer; Hupa, Mikko


    This is the first of two papers concerning the behavior of black liquor during pyrolysis under pressurized conditions. Two industrial kraft liquors were pyrolyzed in a laboratory-scale pressurized single particle reactor and a pressurized grid heater at temperatures ranging from 650 to 1100 degrees C and at pressures between 1 and 20 bar. The dimensions of the chars produced were measured and the specific swollen volume was calculated. Swelling decreased roughly logarithmically over the pressure range 1-20 r. An expression is developed to predict the specific swollen volume at elevated pressure when the volume at 1 bar is known. The bulk density of the char increased with pressure, indicating that liquors will be entrained less easily at higher pressures.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, SJ


    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. (United States)

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


    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


    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. Herbicide hardwood crop tree release in central West Virginia (United States)

    Jeffrey D. Kochenderfer; Shepard M. Zedaker; James E. Johnson; David W. Smith; Gary W. Miller


    Chemical crop tree release treatments were applied to young hardwood stands at three sites in central West Virginia to evaluate the effectiveness of glyphosate as Accord (41.5% SL), imazapyr as Arsenal AC (53.1% SL) and Chopper (27.6% EC), and triclopyr as Garlon 3A (44.4% triethylamine salt SL), and Garlon 4 (61.6% butoxyethyl ester EC) using hack-and-squirt injection...

  13. Canopy structure and tree condition of young, mature, and old-growth Douglas-fir/hardwood forests (United States)

    B.B. Bingham; J.O. Sawyer


    Sixty-two Douglas-fir/hardwood stands ranging from 40 to 560 years old were used to characterize the density; diameter, and height class distributions of canopy hardwoods and conifers in young (40 -100 yr), mature (101 - 200 yr) and old-growth (>200 yr) forests. The crown, bole, disease, disturbance, and cavity conditions of canopy conifers and hardwoods were...

  14. Assessing changes in the U.S. hardwood sawmill industry with a focus on markets and distribution (United States)

    Omar Espinoza; Urs Buehlmann; Matthew Bumgardner; Bob. Smith


    The U.S. hardwood sawmilling industry has experienced significant changes over the past decade. A slowing housing industry, competition from imported products, higher transportation costs, and high stumpage prices have changed the business of manufacturing and marketing hardwood lumber. Also, hardwood lumber buyers are changing their business practices by shortening...

  15. Optimizing wildlife habitat quality and oak regeneration in bottomland hardwoods using midstory control and partial harvests (United States)

    Derek K. Alkire; Andrew W. Ezell; Andrew B. Self


    Bottomland hardwoods can provide both wildlife habitat and timber. However, past high-grading practices limit future income potential and have resulted in undesirable species composition in many areas. Thus, prevalence of desirable oak species should be increased. Our study will attempt to determine the proper harvest level for bottomland hardwoods which will optimize...

  16. Stand conditions immediately following a restoration harvest in an old-growth pine-hardwood remnant (United States)

    D. C. Bragg


    Portions of the Levi Wilcoxon Demonstration Forest (LWDF), a privately owned parcel of old-growth pine and hardwoods in Ashley County, Arkansas, were recently treated to restore conditions similar to some historic accounts of the virgin forest. Following a hardwood-only cut, a post-harvest inventory showed that the number of tree species in the sample area declined...

  17. Manual herbicide application methods for managing vegetation in Appalachian hardwood forests (United States)

    Jeffrey D. Kochenderfer; James N. Kochenderfer; Gary W. Miller


    Four manual herbicide application methods are described for use in Appalachian hardwood forests. Stem injection, basal spray, cut-stump, and foliar spray techniques can be used to control interfering vegetation and promote the development of desirable reproduction and valuable crop trees in hardwood forests. Guidelines are presented to help the user select the...

  18. Possible Demands for Eastern Hardwoods Resulting from Harvest Restrictions in the Pacific (United States)

    Janice K. Wiedenbeck; Philip A. Araman


    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...

  19. Automatic Color Sorting System for Hardwood Edge-Glued Panel Parts (United States)

    Richard W. Conners; D.Earl Kline; Philip A. Araman


    The color sorting of edge-glued panel parts is becoming more important in the manufacture of hardwood products. Consumers, while admiring the natural appearance of hardwoods, do not like excessive color variation across product surfaces. Color uniformity is particularly important today because of the popularity of lightly stained products. Unfortunately, color sorting...

  20. Timber, Browse, and Herbage on Selected Loblolly-Shortleaf Pine-Hardwood Forest Stands (United States)

    Gale L. Wolters; Alton Martin; Warren P. Clary


    A thorough vegetation inventory was made on loblolly-shortleaf pine-hardwood stands scheduled by forest industry for clearcutting, site preparation, and planting to pine in north central Louisiana and southern Arkansas. Overstory timber, on the average, contained about equal proportions of softwood and hardwood basal area. Browse plants ranged from 5,500 to over 70,...

  1. Weight, Volume, and Physical Properties of Major Hardwood Species in the Upland-South (United States)

    Alexander Clark; Douglas R. Phillips; Douglas J. Frederick


    The weight, volume, and physical properties oftrees1 to 20 inchesd.b.h.were determined for sweetgum, yellow-poplar, hickory, post oak, scarlet oak, southern red oak, and white oakin northern Alabama and Mississippi, eastern Arkansas, southern Kentucky and Tennessee. Hard hardwoods, soft hardwoods, and individual species equations are presented for predicting green and...

  2. Crop tree release options for young hardwood stands in North Carolina (United States)

    Jamie L. Schuler; Daniel J. Robison


    Harvesting southern hardwood forests using even-aged reproduction methods commonly regenerate new stands with 20,000 to 50,000 stems per acre. Overstocking and an overabundance of non-commercial tree species are considered major constraints to growing productive and valuable hardwoods. Crop tree release practices have been promoted as an efficient way of thinning young...

  3. Using fire to restore pine/hardwood ecosystems in the Southern Appalachians of North Carolina (United States)

    James M. Vose; Wayne T. Swank; Barton D. Clinton; Ronald L. Hendrick; Amy E. Major


    In the Southern Appalachians, mixed pine/hardwood ecosystems occupy the most xeric sites (i.e., south/west aspect ridge sites). They are typically comprised of varying proportions of pitch pine (Pinus rigida), Virginia pine (Pinus virginiana), and/or shortleaf pine (Pinus echinata) and a mixture of hardwoods, including scarlet oak (Quercus coccinea), chestnut oak (...

  4. International trade of U.S. hardwood lumber and logs, 1990-2013 (United States)

    William G. Luppold; Matthew S. Bumgardner


    United States (U.S.) hardwood log and lumber exports surged in the early- and mid-1970s in response to the adoption of floating exchange rates. However, assessing these changes in international trade became difficult in the 1980s due to increased underreporting of hardwood lumber and log shipments between the U.S. and Canada. By 1990, these data problems were rectified...

  5. Assessing the feasibility and profitability of cable logging in southern upland hardwood forests (United States)

    Chris B. LeDoux; Dennis M. May; Tony Johnson; Richard H. Widmann


    Procedures developed to assess available timber supplies from upland hardwood forest statistics reported by the USDA Forest Services' Forest Inventory and Analysis unit were modified to assess the feasibility and profitability of cable logging in southern upland hardwood forests. Depending on the harvest system and yarding distance used, cable logging can be...

  6. An economic assessment of implementing streamside management zones in central Appalachian hardwood forests (United States)

    Yaoxiang Li; Chris B. LeDoux; Jingxin Wang


    The effects of variable width of streamside management zones (25, 50, 75, and 100 ft) (SMZs) and removal level of trees (10%, 30%, and 50% of basal area) on production and cost of implementing SMZs in central Appalachian hardwood forests were simulated by using a computer model. Harvesting operations were performed on an 80-year-old generated natural hardwood stand...

  7. Key to utilization of hardwoods on pine sites: the shaping-lathe headrig (United States)

    P. Koch


    In past years, only 30% of southern pine biomass (above- and below-ground parts) ended as primary product. Moreover, hardwoods on pine sites were, and in many cases still are, destroyed with no thought of utilization. Now, however, processes have been invented that can raise utilization of each tree- pine and hardwood on pine sites a like to 67% of total biomass,...

  8. U.S. hardwood fiber demand and supply situation : globalization and structural change (United States)

    Peter J. Ince; Irene Durbak


    This paper reviews demand and supply trends for hardwood fiber in the United States. The objective is to illustrate nationwide shifts in demand and supply and show how the hardwood pulpwood market reacts to those shifts at a regional level. Thus, the market situation is illustrated using an economic rationale, and trends are projected under assumptions about future...

  9. Nondestructive evaluation of hardwood logs:CT scanning, machine vision and data utilization (United States)

    Daniel L. Schmoldt; Luis G. Occena; A. Lynn Abbott; Nand K. Gupta


    Sawing of hardwood logs still relies on relatively simple technologies that, in spite of their lack of sophistication, have been successful for many years due to wood?s traditional low cost and ready availability. These characteristics of the hardwood resource have changed dramatically over the past 20 years, however, forcing wood processors to become more efficient in...

  10. Trends in the US hardwood lumber distribution industry: changing products, customers, and services (United States)

    Urs Buehlmann; Omar Espinoza; Matthew Bumgardner; Bob. Smith


    Efficient and effective supply chains are the backbone of any industry, including the forest products industry. As the US secondary hardwood industry has undergone a profound transformation and large parts of the industry have moved offshore, the supply chain is adapting to these new realities. Remaining and new customers of US hardwood lumber distributors tend to be...

  11. Quantifying flooding effects on hardwood seedling survival and growth for bottomland restoration (United States)

    John M. Kabrick; Daniel C. Dey; J.W. Van Sambeek; Mark V. Coggeshall; Douglass F. Jacobs


    Growing interest worldwide in bottomland hardwood restoration necessitates improved ecological understanding of flooding effects on forest tree seedlings using methodology that accurately reflects field conditions. We examined hardwood seedling survival and growth in an outdoor laboratory where the timing, depth, duration, and flow rate of flood water can be carefully...

  12. An Integrated Management Support and Production Control System for Hardwood Forest Products (United States)

    Guillermo A. Mendoza; Roger J. Meimban; William Sprouse; William G. Luppold; Philip A. Araman


    Spreadsheet and simulation models are tools which enable users to analyze a large number of variables affecting hardwood material utilization and profit in a systematic fashion. This paper describes two spreadsheet models; SEASaw and SEAIn, and a hardwood sawmill simulator. SEASaw is designed to estimate the amount of conversion from timber to lumber, while SEAIn is a...

  13. Harem: Hardwood lumber remanufacturing program for maxmizing value based on size, grade and current market prices (United States)

    C.J. Schwehm; P. Klinkhachorn; Charles W. McMillin; Henry A. Huber


    This paper describes an expert system computer program which will determine the optimum way to edge and trim a hardwood board so as to yield the highest dollar value based on the grade, size of each board, and current market prices. The program uses the Automated Hardwood Lumber Grading Program written by Klinkhachorn, et al. for determining the grade of each board...

  14. Factors affecting the merchandising of hardwood logs in the southern tier of New York (United States)

    John E. Wagner; Bryan Smalley; William Luppold


    In many areas of the eastern United States, hardwood boles are sawn into logs and then separated by product before proceeding to future processing. This type of product merchandising is facilitated by large differences in the relative value of hardwood logs of different species and grades. The objective of this study was to analyze the factors influencing the...

  15. Effects of group-selection timber harvest in bottomland hardwoods on fall migrant birds (United States)

    John C. Kilgo; Karl V. Miller; Winston P. Smith


    Due to projected demands for hardwood timber, development of silvicultural practices that provide for adequate regeneration in southeastern bottomland hardwoods without causing undue harm to wildlife resources is critical. Group-selection silviculture involves harvesting a small group of trees, which creates a canopy gap (usually

  16. Timber harvesting patterns for major states in the central, northern, and mid-Atlantic hardwood regions (United States)

    William G. Luppold; Matthew S. Bumgardner


    Timber harvesting is a major disturbance agent influencing the composition and structure of eastern hardwood forests. To better understand timber harvesting practices, we examined roundwood harvesting patterns in 13 eastern states in the Central, Mid-Atlantic, and Northern regions that contained high proportional volumes of hardwood in their forest inventories. Nearly...

  17. Status and trends of bottomland hardwood forests in the mid-Atlantic Region (United States)

    Anita Rose; Steve Meadows


    Bottomland hardwood forests cover approximately 2.9 million acres of the Coastal Plain and Piedmont region of Virginia and North Carolina. As of 2014, 59 percent of bottomland hardwood forests were in the large-diameter stand-size class. Between 2002 and 2014, area of large-diameter sized stands increased, while that of medium- and small-diameter stands decreased,...

  18. Consumer ring count and grain texture preferences of selected eastern United States hardwoods (United States)

    Delton Alderman; Matthew Bumgardner; Scott Bowe; David Brinberg


    Historically, eastern hardwoods have been a staple of forest products production. However, hardwood producers are now faced with serious challenges from substitutable products, such as imports of foreign species, utilization of foreign species in overseas manufacture (e.g., case goods, etc.), and composite-based materials that are imported or manufactured here in the...

  19. Integrating black liquor gasification with pulping - Process simulation, economics and potential benefits (United States)

    Lindstrom, Erik Vilhelm Mathias

    Gasification of black liquor could drastically increase the flexibility and improve the profit potential of a mature industry. The completed work was focused on research around the economics and benefits of its implementation, utilizing laboratory pulping experiments and process simulation. The separation of sodium and sulfur achieved through gasification of recovered black liquor, can be utilized in processes like modified continuous cooking, split sulfidity and green liquor pretreatment pulping, and polysulfide-anthraquinone pulping, to improve pulp yield and properties. Laboratory pulping protocols have been developed for these modified pulping technologies and different process options evaluated. The process simulation work around BLG has led to the development of a WinGEMS module for the low temperature MTCI steam reforming process, and case studies comparing a simulated conventional kraft process to different process options built around the implementation of a BLG unit operation into the kraft recovery cycle. Pulp yield increases of 1-3% points with improved product quality, and the potential for capital and operating cost savings relative to the conventional kraft process have been demonstrated. Process simulation work has shown that the net variable operating cost for a pulping process using BLGCC is highly dependent on the cost of lime kiln fuel and the selling price of green power to the grid. Under the assumptions taken in the performed case study, the BLGCC process combined with split sulfidity or PSAQ pulping operations had net variable operating cost 2-4% greater than the kraft reference. The influence of the sales price of power to the grid is the most significant cost factor. If a sales price increase to 6 ¢/KWh for green power could be achieved, cost savings of about $40/ODtP could be realized in all investigated BLG processes. Other alternatives to improve the process economics around BLG would be to modify or eliminate the lime kiln unit

  20. The Crisis in Black and Black. (United States)

    Hutchinson, Earl Ofari

    These essays explore why the historic conflict between blacks and whites in the United States has become a crisis that divides many African Americans. The changing racial dynamic is not marked by conflicts. between the black middle class and the poor, black men and women, the black intellectual elite and rappers, black politicians and the urban…

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

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


    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...

  2. Enzymatic pulp upgrade for producing high-value cellulose out of a Kraft paper pulp. (United States)

    Hutterer, Christian; Kliba, Gerhard; Punz, Manuel; Fackler, Karin; Potthast, Antje


    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.

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

    International Nuclear Information System (INIS)

    Kjoerk, Anders; Herstad Swaerd, Solvie


    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

  4. Counseling Blacks (United States)

    Vontress, Clemmont E.


    Blacks have developed unique environmental perceptions, values, and attitudes, making it difficult for counselors to establish and maintain positive rapport. This article examines attitudinal ingredients posited by Carl Rogers for relevance to this problem, and suggests in-service training to help counselors and other professionals relate…

  5. Black Willow (United States)

    R. M. Krinard


    Black willow and other species of Salix together comprise a majority of the stocking. Cottonwood is the chief associate, particularly in the early stages, but green ash, sycamore, pecan, persimmon, waterlocust, American elm, baldcypress, red maple, sugarberry, box-elder, and in some areas, silver maple are invaders preceding the next successional stage.

  6. Black Psyllium (United States)

    ... by mouth for up to 6 weeks reduces blood sugar in people with type 2 diabetes. Cancer. Diarrhea. Irritable bowel syndrome (IBS). Other conditions. ... with the dose. Diabetes: Black psyllium can lower blood sugar levels ... with type 2 diabetes by slowing down absorption of carbohydrates. Monitor blood ...

  7. 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


    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

  8. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.


    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  9. Subfossil leaves reveal a new upland hardwood component of the pre-European Piedmont landscape,Lancaster County, Pennsylvania.

    Directory of Open Access Journals (Sweden)

    Sara J Elliott

    Full Text Available Widespread deforestation, agriculture, and construction of milldams by European settlers greatly influenced valley-bottom stream morphology and riparian vegetation in the northeastern USA. The former broad, tussock-sedge wetlands with small, anastomosing channels were converted into today's incised, meandering streams with unstable banks that support mostly weedy, invasive vegetation. Vast accumulations of fine-grained "legacy" sediments that blanket the regional valley-bottom Piedmont landscape now are being reworked from stream banks, significantly impairing the ecological health of downstream water bodies, most notably the Chesapeake Bay. However, potential restoration is impaired by lack of direct knowledge of the pre-settlement riparian and upslope floral ecosystems. We studied the subfossil leaf flora of Denlingers Mill, an obsolete (breached milldam site in southeastern Pennsylvania that exhibits a modern secondary forest growing atop thin soils, above bedrock outcrops immediately adjacent to a modified, incised stream channel. Presumably, an overhanging old-growth forest also existed on this substrate until the early 1700s and was responsible for depositing exceptionally preserved, minimally transported subfossil leaves into hydric soil strata, which immediately underlie post-European settlement legacy sediments. We interpret the eleven identified species of the subfossil assemblage to primarily represent a previously unknown, upland Red Oak-American Beech mixed hardwood forest. Some elements also appear to belong to a valley-margin Red Maple-Black Ash swamp forest, consistent with preliminary data from a nearby site. Thus, our results add significantly to a more complete understanding of the pre-European settlement landscape, especially of the hardwood tree flora. Compared with the modern forest, it is apparent that both lowland and upslope forests in the region have been modified significantly by historical activities. Our study

  10. 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


    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

  11. Crop-tree release increases growth of 12-year-old yellow-poplar and black cherry (United States)

    Neil I. Lamson; H. Clay. Smith; H. Clay. Smith


    Precommercial thinning was done in a 12-year-old Appalachian hardwood sapling stand in West Virginia. Two crop-tree release techniques were used--crown touching and crown touching plus 5 feet. Results indicated that both treatments significantly increased 5-year d.b.h. growth for released yellow-poplar and black cherry crop trees. Although there was a major increase in...

  12. 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:


    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.

  13. 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


    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

  14. 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:; Jylhae, P. (Finnish Forest Research Inst., Kannus (Finland)), Email:; Laitila, J. (Finnish Forest Research Inst., Joensuu (Finland)), Email:; Kaerhae, K. (Metsaeteho Oy, Helsinki (Finland)), Email:


    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.)

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

    Energy Technology Data Exchange (ETDEWEB)



    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)

  16. Polpação soda com aditivos e cinética de deslignificação Kraft


    Almeida, Diego Pierre de


    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...

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

    Energy Technology Data Exchange (ETDEWEB)


    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


    Directory of Open Access Journals (Sweden)

    Lucas Cândido Barbosa


    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.

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

    Energy Technology Data Exchange (ETDEWEB)


    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)

  20. Removal of selected pollutants from aqueous media by hardwood mulch

    International Nuclear Information System (INIS)

    Ray, Asim B.; Selvakumar, Ariamalar; Tafuri, Anthony N.


    Generic hardwood mulch, usually used for landscaping, was utilized to remove several selected pollutants (heavy metals and toxic organic compounds) typically found in urban stormwater (SW) runoff. The hardwood mulch sorbed all the selected pollutants from a spiked stormwater mixture, including copper (Cu 2+ ), cadmium (Cd 2+ ), chromium (Cr 6+ ), lead (Pb 2+ ), zinc (Zn 2+ ), 1,3 dichlorobenzene (DCB), naphthalene (NP), fluoranthene (FA), butylbenzylphthalate (BBP), and benzo(a)pyrene (B[a]P). Masses of the pollutants sorbed depended upon the pollutant species, contact time, and initial concentration which varied from 20 to 100%. Sorption rates of the metals, in general, were more rapid than those of the organics; however, mass removals (percent) of the organics, in contrast to those of the metals, were independent of their initial concentrations. With the exception of Cd, percentages (weight) of the metals removed declined as their initial concentrations decreased. None of the sorbed pollutants desorbed to any significant extent upon extended washing with water. It is quite feasible that in the presence of mulch the uptake of these pollutants by the aquatic species will be reduced significantly

  1. Avian response to bottomland hardwood reforestation: the first 10 years (United States)

    Twedt, D.J.; Wilson, R.R.; Henne-Kerr, J.L.; Grosshuesch, D.A.


    Bttomland hardwood forests were planted on agricultural fields in Mississippi and Louisiana using either predominantly Quercus species (oaks) or Populus deltoides (eastern cottonwood). We assessed avian colonization of these reforested sites between 2 and 10 years after planting. Rapid vertical growth of cottonwoods (circa 2 - 3 m / yr) resulted in sites with forest structure that supported greater species richness of breeding birds, increased Shannon diversity indices, and supported greater territory densities than on sites planted with slower-growing oak species. Grassland birds (Spiza americana [Dickcissel], and Sturnella magna [Eastern Meadowlark]) were indicative of species breeding on oak-dominated reforestation # 10 years old. Agelaius phoeniceus (Red-winged Blackbird) and Colinus virginianus (Northern Bobwhite) characterized cottonwood reforestation # 4 years old, whereas 14 species of shrub-scrub birds (e.g., Passerina cyanea [Indigo Bunting]) and early-successional forest birds (e.g., Vireo gilvus [Warbling Vireo]) typified cottonwood reforestation 5 to 9 years after planting. Rates of daily nest survival did not differ between reforestation strategies. Nest parasitism increased markedly in older cottonwood stands, but was overwhelmed by predation as a cause of nest failure. Based on Partners in Flight prioritization scores and territory densities, the value of cottonwood reforestation for avian conservation was significantly greater than that of oak reforestation during their first 10 years. Because of benefits conferred on breeding birds, we recommend reforestation of bottomland hardwoods include a high proportion of fast-growing, early successional species such as cottonwood.

  2. Biomass models to estimate carbon stocks for hardwood tree species

    Energy Technology Data Exchange (ETDEWEB)

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


    To estimate forest carbon pools from forest inventories it is necessary to have biomass models or biomass expansion factors. In this study, tree biomass models were developed for the main hardwood forest species in Spain: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europaea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica and Quercus suber. Different tree biomass components were considered: stem with bark, branches of different sizes, above and belowground biomass. For each species, a system of equations was fitted using seemingly unrelated regression, fulfilling the additivity property between biomass components. Diameter and total height were explored as independent variables. All models included tree diameter whereas for the majority of species, total height was only considered in the stem biomass models and in some of the branch models. The comparison of the new biomass models with previous models fitted separately for each tree component indicated an improvement in the accuracy of the models. A mean reduction of 20% in the root mean square error and a mean increase in the model efficiency of 7% in comparison with recently published models. So, the fitted models allow estimating more accurately the biomass stock in hardwood species from the Spanish National Forest Inventory data. (Author) 45 refs.

  3. Rooting of hardwood cuttings of Roxo de Valinhos fig (Ficus carica L. with different propagation strategies

    Directory of Open Access Journals (Sweden)

    Gilmar Antônio Nava


    Full Text Available The objective of this study was to evaluate the substrate, cuttings collection time, the position and the cutting depth, and the propagation environment on rooting of 'Purple Valinhos' fig tree cuttings in Southwestern Paraná, Brazil. Two experiments were carried out at UTFPR, Câmpus Dois Vizinhos, with hardwoods cuttings from Roxo de Valinhos fig tree. The first experiment used a randomized block design, in 3 x 3 x 2 factorial (substrate x environment x collection time, with four replications of 10 cuttings per plot. The cuttings were collected in the first fifteen days of July and August. The substrates were sand, soil and the mixture of these [1:1 (v / v]. The environments used were open sky, tunnel with plastic cover and tunnel with half-shade black net cover. The second experiment used a randomized block design, 2 x 2 x 3 factorial (shoot cutting position x soil cover x shoot cutting depth, with four replications of 12 cuttings per plot. In the factor position, the vertically (0 º inclination and inclined (45 º inclination shoot cuttings were evaluated. Soil cover was tested with mulching plastic cover or not. The tested depths were 1/3, 1/2 and 2/3 in relation to the total length of the shoot cutting. In both experiments, the following were analyzed: rooting and mortality indices, number of leaves and primary shoots, length of the three largest roots per cutting. It was conclude that, the protected environment with plastic cover on sand as substrate must recommended for the rooting of fig estaca, collecting them in the first half of July. The inclination position and cutting depth of the estaca and the substrate coverage with plastic mulching did not influence the results.

  4. Generation of Hydrogen, Lignin and Sodium Hydroxide from Pulping Black Liquor by Electrolysis

    Directory of Open Access Journals (Sweden)

    Guangzai Nong


    Full Text Available Black liquor is generated in Kraft pulping of wood or non-wood raw material in pulp mills, and regarded as a renewable resource. The objective of this paper was to develop an effective means to remove the water pollutants by recovery of both lignin and sodium hydroxide from black liquor, based on electrolysis. The treatment of a 1000 mL of black liquor (122 g/L solid contents consumed 345.6 kJ of electric energy, and led to the generation of 30.7 g of sodium hydroxide, 0.82 g of hydrogen gas and 52.1 g of biomass solids. Therefore, the recovery ratios of elemental sodium and biomass solids are 80.4% and 76%, respectively. Treating black liquor by electrolysis is an environmentally friendly technology that can, in particular, be an alternative process in addressing the environmental issues of pulping waste liquor to the small-scale mills without black liquor recovery.

  5. Manager's handbook for northern hardwoods in the north-central states. (United States)

    Carl H. Tubbs


    Provides a key for the resource manager to use in choosing silvicultural practices for the management of northern hardwoods. Control of stand composition, growth, and stand establishment for timber production, water, wildlife, and recreation are discussed.

  6. Carbon Storage of bottomland hardwood afforestation in the Lower Mississippi Valley, U.S.A. (United States)

    David T. Shoch; Gary Kaster; Aaron Hohl; Ray Souter


    The emerging carbon market is an increasingly important source of finance for bottomland hardwood afforestation in the Lower Mississippi River Valley (LMV). Notwithstanding, there is a scarcity of empirical...

  7. Comparison of two cut-to-length harvesting systems operating in eastern hardwoods (United States)

    Chris B. LeDoux; Niel K. Huyler


    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.

  8. Photo guide for estimating risk to hardwood trees during prescribed burning operations in eastern oak forests (United States)

    Patrick H. Brose


    A field guide of 40 photographs of common hardwood trees of eastern oak forests and fuel loadings surrounding their bases. The guide contains instructions on how to rapidly assess a tree's likelihood to be damaged or killed by prescribed burning.



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


    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...

  10. Contemporary Black Theatre. (United States)

    Thomas, Pearl

    The distinguishable black theatre in America, mirroring a distinguishable black experience, is an artistic product which demands audience involvement. Both the Afro-American oral tradition and the art of gesture are integral aspects of black theatre. In addition, the tragedy found black theatre is not tragedy in the classic sense, as blacks feel…

  11. The shaping-lathe headrig-- key to utilization of hardwoods growing on southern pine sites (United States)

    P. Koch


    For every cubic foot of pine on southern pine sites, there is about 0.8 cubic foot of hardwood. The shaping-lathe headrig, now in the final stages of commercialization, is a key to utilizing these small mixed hardwoods for pallets and industrial lumber. Lathe residues in the form of flakes can be the raw material for a new major industry manufacturing exterior...

  12. 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


    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.

  13. 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


    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.

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

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


    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.

  15. 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.


    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

  16. Black widow spider (United States)

    ... Black widow spider To use the sharing features on this page, please enable JavaScript. The black widow spider (Latrodectus) has a shiny black body with a ...

  17. Tree regeneration by seed in bottomland hardwood forests: A review (United States)

    Kroschel, Whitney A.; King, Sammy L.; Keim, Richard F.


    Bottomland hardwood forests (BLH) are found in temperate, humid regions of the southeastern US, primarily on alluvial floodplains adjacent to rivers. Altered hydrology in rivers and floodplains has caused changes in stand development and species composition of BLHs. We hypothesize that the driving mechanisms behind these changes are related to the regeneration process because of the complexity of recruitment and the vulnerability of species at that age in development. Here we review the state of our understanding regarding BLH regeneration, and identify potential bottlenecks throughout the stages of seed production, seed dispersal, germination, establishment, and survival. Our process-level understanding of regeneration by seed in BLHs is rudimentary, thus limiting our ability to predict the effects of hydrologic alterations on species composition. By focusing future research on the appropriate stages of regeneration, we can better understand the sources of forest-community transitions across the diverse range of BLH systems.

  18. Facilitating Oak and Hickory Regeneration in Mature Central Hardwood Forests

    Directory of Open Access Journals (Sweden)

    Eric J. Holzmueller


    Full Text Available Advanced oak and hickory regeneration is often absent in mature oak-hickory forests in the Central Hardwood Region of the United States. Prescribed fire and thinning, alone and combined, are commonly prescribed silvicultural treatments that are recommended to initiate the regeneration process. This study examined the regeneration response in three mature oak stands following four treatments: (1 thin, (2 burn, (3 thinning and burning, or (4 no treatment (control. Ten years after initial treatment, results indicate that oak and hickory seedlings had greater height and diameter in the thinning and burning treatment compared to the control and that this treatment may help facilitate desirable regeneration in mature oak-hickory forests.

  19. Microhabitat features influencing habitat use by Florida black bears

    Directory of Open Access Journals (Sweden)

    Dana L. Karelus


    Full Text Available Understanding fine-scale habitat needs of species and the factors influencing heterogeneous use of habitat within home range would help identify limiting resources and inform habitat management practices. This information is especially important for large mammals living in fragmented habitats where resources may be scarcer and more patchily distributed than in contiguous habitats. Using bihourly Global Position System (GPS location data collected from 10 individuals during 2011–2014, we investigated microhabitat features of areas within home ranges that received high vs. low intensity of use by Florida black bears (Ursus americanus floridanus in north-central, Florida. We identified areas receiving high and low levels of use by bears based on their utilization distributions estimated with the dynamic Brownian bridge movement model, and performed vegetation sampling at bear locations within high- and low-use areas. Using univariate analyses and generalized linear mixed models, we found that (1 canopy cover, visual obstruction, and hardwood density were important in defining high-use sites; (2 the probability of high use was positively associated with principal components that represented habitat closer to creeks and with high canopy and shrub cover and higher hardwood densities, likely characteristic of forested wetlands; and (3 the probability of high use was, to a lesser extent, associated with principal components that represented habitat with high canopy cover, high pine density, and low visual obstruction and hardwood density; likely representing sand pine and pine plantations. Our results indicate that the high bear-use sites were in forested wetlands, where cover and food resources for bears are likely to occur in higher abundance. Habitat management plans whereby bears are a focal species should aim to increase the availability and quality of forested wetlands. Keywords: Habitat selection, Heterogeneous habitat use, Forest management

  20. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili


    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  1. Cracking and Corrosion of Composite Tubes in Black Liquor Recovery Boiler Primary Air Ports

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, James R.; Singbeil, Douglas L.; Sarma, Gorti B.; Kish, Joseph R.; Yuan, Jerry; Frederick, Laurie A.; Choudhury, Kimberly A.; Gorog, J. Peter; Jetté, Francois R.; Hubbard, Camden R.; Swindeman, Robert W.; Singh, Prett M.; Maziasz, Phillip J.


    Black liquor recovery boilers are an essential part of kraft mills. Their design and operating procedures have changed over time with the goal of providing improved boiler performance. These performance improvements are frequently associated with an increase in heat flux and/or operating temperature with a subsequent increase in the demand on structural materials associated with operation at higher temperatures and/or in more corrosive environments. Improvements in structural materials have therefore been required. In most cases the alternate materials have provided acceptable solutions. However, in some cases the alternate materials have solved the original problem but introduced new issues. This report addresses the performance of materials in the tubes forming primary air port openings and, particularly, the problems associated with use of stainless steel clad carbon steel tubes and the solutions that have been identified.

  2. Nine-year performance of four hardwoods on a harvested site with and without fertilizer tree shelters, and weed mats in southern Illinois (United States)

    Felix, Jr. Ponder; J.W. Van Sambeek


    Quality hardwood species often dominate stands on intermediate to high quality sites before regeneration. However, successfully regenerating these species after the harvest is rarely achieved on these sites. Hardwood species were planted on a high quality site in southern Illinois after clearcutting to study the effect of several cultural practices on the hardwoods...

  3. Characterization of cytokinin signaling and homeostasis gene families in two hardwood tree species: Populus trichocarpa and Prunus persica. (United States)

    Immanen, Juha; Nieminen, Kaisa; Duchens Silva, Héctor; Rodríguez Rojas, Fernanda; Meisel, Lee A; Silva, Herman; Albert, Victor A; Hvidsten, Torgeir R; Helariutta, Ykä


    Through the diversity of cytokinin regulated processes, this phytohormone has a profound impact on plant growth and development. Cytokinin signaling is involved in the control of apical and lateral meristem activity, branching pattern of the shoot, and leaf senescence. These processes influence several traits, including the stem diameter, shoot architecture, and perennial life cycle, which define the development of woody plants. To facilitate research about the role of cytokinin in regulation of woody plant development, we have identified genes associated with cytokinin signaling and homeostasis pathways from two hardwood tree species. Taking advantage of the sequenced black cottonwood (Populus trichocarpa) and peach (Prunus persica) genomes, we have compiled a comprehensive list of genes involved in these pathways. We identified genes belonging to the six families of cytokinin oxidases (CKXs), isopentenyl transferases (IPTs), LONELY GUY genes (LOGs), two-component receptors, histidine containing phosphotransmitters (HPts), and response regulators (RRs). All together 85 Populus and 45 Prunus genes were identified, and compared to their Arabidopsis orthologs through phylogenetic analyses. In general, when compared to Arabidopsis, differences in gene family structure were often seen in only one of the two tree species. However, one class of genes associated with cytokinin signal transduction, the CKI1-like family of two-component histidine kinases, was larger in both Populus and Prunus than in Arabidopsis.

  4. Structure of Thermobifida fusca DyP-type peroxidase and activity towards Kraft lignin and lignin model compounds. (United States)

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


    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.

  5. Pilot study investigating ambient air toxics emissions near a Canadian kraft pulp and paper facility in Pictou County, Nova Scotia. (United States)

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


    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.

  6. Corporate Image and Public Health: An Analysis of the Philip Morris, Kraft, and Nestlé Websites (United States)



    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

  7. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io


    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  8. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.


    Conditions for the formation of a black hole are considered, and the properties of black holes. The possibility of Cygnus X-1 as a black hole is discussed. Einstein's theory of general relativity in relation to the formation of black holes is discussed. (U.K.)

  9. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M


    Methods and results of searching for stellar mass black holes in binary systems and for supermassive black holes in galactic nuclei of different types are described. As of now (June 2002), a total of 100 black hole candidates are known. All the necessary conditions Einstein's General Relativity imposes on the observational properties of black holes are satisfied for candidate objects available, thus further assuring the existence of black holes in the Universe. Prospects for obtaining sufficient criteria for reliably distinguishing candidate black holes from real black holes are discussed. (reviews of topical problems)

  10. New black liquor combustion characteristics III; Mustalipeaen uudet poltto-ominaisuudet III

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Forssen, M.; Backman, R.; Enestam, S.; Lauren, T.; Skrifvars, B.J. [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group


    The main purposes in this work is to: 1. Compare black liquor combustion characterization results to recovery boiler experiences. 2. Study the mechanisms of sodium release in black liquor combustion In the first part results from black liquor combustion characterization tests developed by Aabo Akademi University will be compared to experiences at four Finnish kraft recovery boilers. When comparing the laboratory data to the compiled field data emphasis will be put on the behavior of the black liquor during burning, the release of sodium and potassium, the melting behavior of the deposits and the NO and SO{sub 2} emissions. The main purpose in the second part of the work is to study the release mechanisms of sodium from black liquor char during combustion. Sodium is mainly released from the char by the mechanism where the molten sodiumcarbonate reacts with the char carbon. The study is divided into four subtasks and is performed mainly by conducting experiments in laboratory scale devices: (1) Sodium release during char reactions is studied for different liquors by analyzing the amount of sodium remaining in char after different holding times in a hot inert atmosphere. (2) A DTA/TGA apparatus is used to study in isothermal conditions the char reactions on prepyrolyzed char. (3) The effect of the form of sodium on the sodium release during char reactions. Black liquors added with different sodium salts (Na{sub 2}CO{sub 3}, Na{sub 2}SO{sub 4}, Na{sub 2}S{sub 2}O{sub 2}, Na{sub 2}S sekae NaCl) are used in experiments as in subtask 1. (4) Sodium release during combustion (2-5 % O{sub 2}) of single black liquor particles

  11. Decline in the U.S. furniture industry: a case study of the impacts to the hardwood lumber supply chain (United States)

    Shawn T. Grushecky; Urs Buehlmann; Al Schuler; William Luppold; Ed Cesa


    Traditionally, the wood household furniture industry has accounted for a sizeable portion of total hardwood lumber use in the United States. However, for more than a decade, imports have gained an increasing share of the hardwood furniture market, and lumber consumption by this industry has declined dramatically in the last 5 years. We used a case study methodology to...

  12. Thirteen Year Loblolly Pine Growth Following Machine Application of Cut-Stump Treament Herbicides For Hardwood Stump-Sprout Control (United States)

    Clyde G. Vidrine; John C. Adams


    Thirteen year growth results of 1-0 out-planted loblolly pine seedlings on nonintensively prepared up-land mixed pine-hardwood sites receiving machine applied cut-stump treatment (CST) herbicides onto hardwood stumps at the time of harvesting is presented. Plantation pine growth shows significantly higher growth for pine in the CST treated plots compared to non-CST...

  13. Development of the selection system in northern hardwood forests of the Lake States: an 80-year silviculture research legacy (United States)

    Christel Kern; Gus Erdmann; Laura Kenefic; Brian Palik; Terry. Strong


    The northern hardwood research program at the Dukes Experimental Forest in Michigan and Argonne Experimental Forest in Wisconsin has been adapting to changing management and social objectives for more than 80 years. In 1926, the first northern hardwood silviculture study was established in old-growth stands at the Dukes Experimental Forest. In response to social...

  14. Employment changes in U.S. hardwood lumber consuming industries during economic expansions and contractions since 1991 (United States)

    William G. Luppold; Matt Bumgardner


    Understanding employment trends is important for discerning the economic vitality of U.S. hardwood lumber users. After a period of growth in the 1990s, employment in industries consuming hardwood lumber has declined in the 21st century. The wood household furniture industry has experienced the greatest decline, with North Carolina, Virginia, and California being the...

  15. Relationships between prescribed burning and wildfire occurrence and intensity in pine-hardwood forests in north Mississippi, USA (United States)

    Stephen Brewer; Corey Rogers


    Using Geographic Information Systems and US Forest Service data, we examined relationships between prescribed burning (from 1979 to 2000) and the incidence, size, and intensity of wildfires (from 1995 to 2000) in a landscape containing formerly fire-suppressed, closed-canopy hardwood and pine-hardwood forests. Results of hazard (failure) analyses did not show an...

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

    International Nuclear Information System (INIS)

    Takyi-Lartey, Rita


    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

  17. A Dancing Black Hole (United States)

    Shoemaker, Deirdre; Smith, Kenneth; Schnetter, Erik; Fiske, David; Laguna, Pablo; Pullin, Jorge


    Recently, stationary black holes have been successfully simulated for up to times of approximately 600-1000M, where M is the mass of the black hole. Considering that the expected burst of gravitational radiation from a binary black hole merger would last approximately 200-500M, black hole codes are approaching the point where simulations of mergers may be feasible. We will present two types of simulations of single black holes obtained with a code based on the Baumgarte-Shapiro-Shibata-Nakamura formulation of the Einstein evolution equations. One type of simulations addresses the stability properties of stationary black hole evolutions. The second type of simulations demonstrates the ability of our code to move a black hole through the computational domain. This is accomplished by shifting the stationary black hole solution to a coordinate system in which the location of the black hole is time dependent.

  18. Foraging behavior of pileated woodpeckers in partial cut and uncut bottomland hardwood forest (United States)

    Newell, P.; King, Sammy L.; Kaller, Michael D.


    In bottomland hardwood forests, partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife like Louisiana black bear (Ursus americanus luteolus), white-tailed deer (Odocoileus virginianus), and Neotropical migrants. Although partial cutting may be beneficial to some species, those that use dead wood may be negatively affected since large diameter and poor quality trees (deformed, moribund, or dead) are rare, but normally targeted for removal. On the other hand, partial cutting can create dead wood if logging slash is left on-site. We studied foraging behavior of pileated woodpeckers (Dryocopus pileatus) in one- and two-year-old partial cuts designed to benefit priority species and in uncut forest during winter, spring, and summer of 2006 and 2007 in Louisiana. Males and females did not differ in their use of tree species, dbh class, decay class, foraging height, use of foraging tactics or substrate types; however, males foraged on larger substrates than females. In both partial cut and uncut forest, standing live trees were most frequently used (83% compared to 14% for standing dead trees and 3% for coarse woody debris); however, dead trees were selected (i.e. used out of proportion to availability). Overcup oak (Quercus lyrata) and bitter pecan (Carya aquatica) were also selected and sugarberry (Celtis laevigata) avoided. Pileated woodpeckers selected trees >= 50 cm dbh and avoided trees in smaller dbh classes (10-20 cm). Density of selected foraging substrates was the same in partial cut and uncut forest. Of the foraging substrates, woodpeckers spent 54% of foraging time on live branches and boles, 37% on dead branches and boles, and 9% on vines. Of the foraging tactics, the highest proportion of foraging time was spent excavating (58%), followed by pecking (14%), gleaning (14%), scaling (7%), berry-eating (4%), and probing (3%). Woodpecker use of foraging tactics and substrates, and foraging height and substrate

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


    Silva, Mariléa Pinto da


    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...

  20. 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.


    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)

  1. Reductive de-polymerization of kraft lignin for chemicals and fuels using formic acid as an in-situ hydrogen source. (United States)

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


    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.


    Directory of Open Access Journals (Sweden)

    Maria Cladis Mezzomo da Silva


    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

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

  4. 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)


    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.

  5. 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


    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...

  6. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    large values of Ф, black holes do form and for small values the scalar field ... on the near side of the ridge ultimately evolve to form black holes while those configu- ... The inset shows a bird's eye view looking down on the saddle point.

  7. The Black Studies Boondoggle (United States)

    Long, Richard A.


    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  8. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke


    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair - degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  9. Immunostimulation and yellow head virus (YHV) disease resistance induced by a lignin-based pulping by-product in black tiger shrimp (Penaeus monodon Linn.). (United States)

    Srisapoome, Prapansak; Hamano, Kaoru; Tsutsui, Isao; Iiyama, Kenji


    Yellow head virus (YHV) is classified as one of the most serious pathogens causing a harmful disease in many penaeids, especially black tiger shrimp (Penaeus monodon), with high economic loss. To determine a potent and practical prophylactic strategy for controlling this disease, the toxicity of the by-product kraft lignin and its ability to control severe YHV infection were investigated in juvenile black tiger shrimp (15.9 ± 1.2 g body weight). The median lethal dosage at 96 h (96-hrs LD 50 ) of lignin in shrimp was 297 mg/L. Lignin was further added to shrimp diets via top-dressing to assess its ability to elicit immune stimulation activity. At 14 days after feeding, shrimp fed 1, 3, 5 and 10 g of lignin/kg of diet exhibited significantly higher levels of phagocytic activity (PA) than the control group (P  0.05). Additionally, lignin supplementation at 1-10 g/kg for 14 days failed to protect experimental shrimp against YHV infection. The antiviral activity of lignin against YHV in black tiger shrimp was notable in vitro because compared to control shrimp (96.7 ± 5.8%; P by-product kraft lignin efficiently inhibits YHV infection in black tiger shrimp. This information will facilitate the development of practical methods to control yellow head disease in the marine shrimp culture industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)


    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  11. Black holes without firewalls (United States)

    Larjo, Klaus; Lowe, David A.; Thorlacius, Larus


    The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

  12. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.


    Recent work, which has been investigating the use of the concept of entropy with respect to gravitating systems, black holes and the universe as a whole, is discussed. The resulting theory of black holes assigns a finite temperature to them -about 10 -7 K for ordinary black holes of stellar mass -which is in complete agreement with thermodynamical concepts. It is also shown that black holes must continuously emit particles just like ordinary bodies which have a certain temperature. (U.K.)

  13. Sediment retention in a bottomland hardwood wetland in Eastern Arkansas (United States)

    Kleiss, B.A.


    One of the often-stated functions of wetlands is their ability to remove sediments and other particulates from water, thus improving water quality in the adjacent aquatic system. However, actual rates of suspended sediment removal have rarely been measured in freshwater wetland systems. To address this issue, suspended sediment dynamics were measured in a 85-km2 bottomland hardwood (BLH) wetland adjacent to the highly turbid Cache River in eastern Arkansas during the 1988-1990 water years. A suspended sediment mass balance was calculated using depth-integrated, flow-weighted daily measurements at wetland inflow and outflow points. Over the three-year period, suspended sediment load decreased an average of 14% between upstream and downstream sampling points. To test the idea that the suspended sediments were retained by the adjacent wetland and to determine what portion of the BLH forest was most responsible for retaining the suspended sediments, concurrent measurements of sediment accretion were made at 30 sites in the wetland using feldspar clay marker horizons, sedimentation disks, the 137cesium method, and dendrogeomorphic techniques. Sedimentation rates exceeding 1 cm/yr were measured in frequently flooded areas dominated by Nyssa aquatica and Taxodium distichum. Maximum sedimentation rates did not occur on the natural levee, as would be predicted by classical fluvial geomorphology, but in the "first bottom," where retention time of the water reached a maximum. Multiple regression was used to relate sedimentation rates with several physical and biological factors. A combination of distance from the river, flood duration, and tree basal area accounted for nearly 90% of the variation in sedimentation rates.

  14. Monopole Black Hole Skyrmions


    Moss, Ian G; Shiiki, N; Winstanley, E


    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  15. What is black hole?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is black hole? Possible end phase of a star: A star is a massive, luminous ball of plasma having continuous nuclear burning. Star exhausts nuclear fuel →. White Dwarf, Neutron Star, Black Hole. Black hole's gravitational field is so powerful that even ...

  16. Genocide and Black Ecology (United States)

    Sinnette, Calvin H.


    Contends that the survival of black people is in serious jeopardy as is evidenced in contemporary discussions on the worldwide plight of black people, and that an exhaustive study of the problem in its many dimensions is seriously lacking; the moral and ethical issues of genocide require examination from a black perspective. (JW)

  17. 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


    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

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

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


    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.


    Directory of Open Access Journals (Sweden)

    Habip Eroğlu


    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.

  20. 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


    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

  1. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.


    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  2. Bottomland Hardwoods of the Mississippi Alluvial Valley: Characteristics and Management of Natural Function, Structure, and Composition (United States)

    Paul B. Hamel; Thomas L. Foti; [Editors


    A symposium entitled "Bottomland hardwoods of the Mississippi Alluvial Valley: characteristics and management of natural function, structure, and composition" convened on October 28, 1995, as part of the Natural Areas Conference, October 25-28, 1995, In Fayetteville, AR. The symposium's goal was to provide informatibn that managers need to begin...

  3. Ten year regeneration of southern Appalachian hardwood clearcuts after controlling residual trees (United States)

    P.M. Zaldivar-Garcia; D.T. Tew


    Two upland hardwood stands were clearcut in 1978 and three treatments to control the unmerchantable and/or cull trees were applied. The treatments applied to the residual trees were chainsaw felling, herbicide injection, and a control, where residual trees were left standing. Regeneration was sampled 10 years after the cutting.

  4. A Machine Vision System for Automatically Grading Hardwood Lumber - (Industrial Metrology) (United States)

    Richard W. Conners; Tai-Hoon Cho; Chong T. Ng; Thomas T. Drayer; Philip A. Araman; Robert L. Brisbon


    Any automatic system for grading hardwood lumber can conceptually be divided into two components. One of these is a machine vision system for locating and identifying grading defects. The other is an automatic grading program that accepts as input the output of the machine vision system and, based on these data, determines the grade of a board. The progress that has...

  5. Automated grading, upgrading, and cuttings prediction of surfaced dry hardwood lumber (United States)

    Sang-Mook Lee; Phil Araman; A.Lynn Abbott; Matthew F. Winn


    This paper concerns the scanning, sawing, and grading of kiln-dried hardwood lumber. A prototype system is described that uses laser sources and a video camera to scan boards. The system automatically detects defects and wane, searches for optimal sawing solutions, and then estimates the grades of the boards that would result. The goal is to derive maximum commercial...

  6. A Multiple Sensor Machine Vision System for Automatic Hardwood Feature Detection (United States)

    D. Earl Kline; Richard W. Conners; Daniel L. Schmoldt; Philip A. Araman; Robert L. Brisbin


    A multiple sensor machine vision prototype is being developed to scan full size hardwood lumber at industrial speeds for automatically detecting features such as knots holes, wane, stain, splits, checks, and color. The prototype integrates a multiple sensor imaging system, a materials handling system, a computer system, and application software. The prototype provides...

  7. Hardwood log grades and lumber grade yields for factory lumber logs (United States)

    Leland F. Hanks; Glenn L. Gammon; Robert L. Brisbin; Everette D. Rast


    The USDA Forest Service Standard Grades for Hardwood Factory Lumber Logs are described, and lumber grade yields for 16 species and 2 species groups are presented by log grade and log diameter. The grades enable foresters, log buyers, and log sellers to select and grade those log suitable for conversion into standard factory grade lumber. By using the apropriate lumber...

  8. Climatic and pollution influences on ecosystem processes in northern hardwood forests (United States)

    Kurt S. Pregitzer; David D. Reed; Glenn D. Mroz; Andrew J. Burton; John A. Witter; Donald A. Zak


    The Michigan gradient study was established in 1987 to examine the effects of climate and atmospheric deposition on forest productivity and ecosystem processes in the Great Lakes region. Four intensively-monitored northern hardwood study sites are located along a climatic and pollutant gradient extending from southern lower Michigan to northwestern upper Michigan. The...

  9. Suitability of the line intersect method for sampling hardwood logging residues (United States)

    A. Jeff Martin


    The line intersect method of sampling logging residues was tested in Appalachian hardwoods and was found to provide unbiased estimates of the volume of residue in cubic feet per acre. Thirty-two chains of sample line were established on each of sixteen 1-acre plots on cutover areas in a variety of conditions. Estimates from these samples were then compared to actual...

  10. Weight, Volume, and Physical Properties of Major Hardwood Species in the Piedmont (United States)

    Alexander Clark; Douglas R. Phillips; Douglas J. Frederick


    Weight, volume, and physical properties of trees 1 to 20 inches d.b.h.were determined for red maple, sweetgum, sycamore, yellow-poplar, elm, hickory, chestnut oak, scarlet oak, southern red oak, and white oak in the Piedmont of the Southeastern United States. A total of 772 trees were destructively sampled at 16 locations from Viryinia to Alabama. Hard hardwoods, soft...

  11. Relationships between growth, quality, and stocking within managed old-growth northern hardwoods (United States)

    Chris Gronewold; Anthony W. D' Amato; Brian J. Palik


    An understanding of long-term growth dynamics is central to the development of sustainable uneven-aged silvicultural systems for northern hardwood forests in eastern North America. Of particular importance are quantitative assessments of the relationships between stocking control and long-term growth and quality development. This study examined these relationships in a...

  12. 77 FR 65172 - Hardwood and Decorative Plywood From the People's Republic of China: Initiation of Antidumping... (United States)


    ... feel are relevant to the development of an accurate listing of physical characteristics. Specifically... Department of Commerce building. In determining whether Petitioners have standing under section 732(c)(4)(A... hardwood and decorative plywood sold by Chinese exporters, as identified in affidavits regarding U.S. price...

  13. Impact of harvesting and atmospheric pollution on nutrient depletion of eastern US hardwood forests (United States)

    M.B. Adams; J.A. Burger; A.B. Jenkins; L. Zelazny


    The eastern hardwood forests of the US may be threatened by the changing atmospheric chemistry and by changes in harvesting levels. Many studies have documented accelerated base cation losses with intensive forest harvesting. Acidic deposition can also alter nutrient cycling in these forests. The combination of increased harvesting, shorter rotations, and more...

  14. Reptile and amphibian response to season of burn in an upland hardwood forest (United States)

    Cathryn H. Greenberg; Tyler Seiboldt; Tara L. Keyser; W. Henry McNab; Patrick Scott; Janis Bush; Christopher E. Moorman


    Growing-season burns are increasingly used in upland hardwood forest for multiple forest management goals. Many species of reptiles and amphibians are ground-dwelling, potentially increasing their vulnerability to prescribed fire, especially during the growing-season when they are most active. We used drift fences with pitfall traps to experimentally assess how...

  15. Use of plastic films for weed control during field establishment of micropropagated hardwoods (United States)

    J. W. Van Sambeek; John E. Preece; Carl A. Huetteman; Paul L. Roth


    This study compares the use of plastic films to conventional methods for establishing hardwoods on a recently cultivated old field site using 1-year-old micropropagated plantlets of white ash (Fraxinus americana L.) and silver maple (Acer saccharinum L.). After one growing season in the field, height of plantlets with all weed...

  16. Influence of Product and Supplier Attributes on Hardwood Lumber Purchase Decisions (United States)

    Craig L. Forbes; Steven A. Sinclair; Robert J. Bush; Philip A. Araman


    This study determined the influence of product and supplier attributes on hardwood lumber purchases by wood furniture manufacturers and investigated differences across manufacturer type, geographic region, firm size, and kiln ownership. Professional lumber buyers rated the importance and difference across suppliers of various attributes. Purchase influence scores were...

  17. Snag Condition and Woodpecker Foraging Ecology in a Bottomland Hardwood Forest (United States)

    Richard N. Conner; Stanley D. Jones; Gretchen D. Jones


    We studied woodpecker foraging behavior, snag quality, and surrounding habitat in a bottomland hardwood forest in the Stephen F. Austin Experimental Forest from December 1984 through November 1986. The amount and location of woodpecker foraging excavations indicated that woodpeckers excavated mainly at the well-decayed tops and bases of snags. Woodpeckers preferred to...

  18. Control of decay in bolts and logs of northern hardwoods during storage (United States)

    Theodore C. Scheffer; T. W. Jones


    Many wood-using plants in the Northeast store large quantities of hardwood logs for rather long periods. Sometimes a large volume of the wood is spoiled by decay during the storage period. A number of people have asked: "How can we prevent this loss?"

  19. Nesting Ecology of Wood Thrush (Turdidae: Passeriformes) in Hardwood Forests of South Carolina (United States)

    Robert A. Sargent; John C. Kilgo; Brian R. Chapman; Karl V. Miller


    We studied nesting success of the Wood Thrush (Hylocichla mustelina) in bottomland and upland hardwood forests in South Carolina. Twenty-one of 26 nests (80.8%) were located in bottomland sites, and 76.2% of these nests were in narrow (

  20. Natural regeneration of northern hardwoods in the northern Great Lakes Region. (United States)

    Carl H. Tubbs


    Reviews silvical and silvicultural information about natural regeneration pertinent to forestry practices in Lake State northern hardwood types. Seed production; effects of light, moisture, temperature and competition on establishment and growth; and how damage affects mortality rates and form are covered. Clearcutting, selection, and shelterwood experiments are...

  1. Influences of Herbivory and Canopy Opening Size on Forest Regeneration in a Southern Bottomland Hardwood Forest (United States)

    Steven B. Castleberry; W. Mark Ford; Carl V. Miller; Winston P. Smith


    We examined the effects of white-tailed deer (Odocoileus virginianus) browsing and canopy opening size on relative abundance and diversity of woody and herbaceous regeneration in various sized forest openings in a southern, bottomland hardwood forest over three growing seasons (1995-1997). We created 36 canopy openings (gaps), ranging from 7 to 40m...

  2. Establishing even-age northern hardwood regeneration by the shelterwood method--a preliminary guide. (United States)

    Richard M. Godman; Carl H. Tubbs


    The shelterwood system of regeneration with northern hardwoods is a reliable method of obtaining even-age stands of both tolerant and moderately tolerant species. Details of applying the two-cut system are described along with the necessary modifications for encouraging moderately tolerant species.

  3. Hardwood Face Veneer and Plywood Mill Closures in Michigan and Wisconsin Since 1950 (United States)

    Lewis T. Hendricks


    In recent years there has been a great deal of concern about the closure of numberous hardwood face veneer and plywood mills in Michigan and Wisconsin. As part of an overall study of that industry in the northern Lake States region, the basic reasons leading to the closure of these mills were investigated. In the past 15 years, there have been eight known mill...

  4. 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


    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.

  5. 78 FR 16250 - Hardwood and Decorative Plywood From the People's Republic of China: Amended Preliminary... (United States)


    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-987] Hardwood and Decorative..., International Trade Administration, Department of Commerce. SUMMARY: The Department of Commerce (the Department..., Import Administration, International Trade Administration, U.S. Department of Commerce, 14th Street and...

  6. The frequency and level of sweep in mixed hardwood saw logs in the eastern United States (United States)

    Peter Hamner; Marshall S. White; Philip A. Araman


    Hardwood sawmills traditionally saw logs in a manner that either orients sawlines parallel to the log central axis (straight sawing) or the log surface (allowing for taper). Sweep is characterized as uniform curvature along the entire length of a log. For logs with sweep, lumber yield losses from straight and taper sawing increase with increasing levels of sweep. Curve...

  7. Species diversity of polyporoid and corticioid fungi in northern hardwood forests with differing management histories (United States)

    Daniel L. Lindner; Harold H., Jr. Burdsall; Glen R. Stanosz


    Effects of forest management on fungal diversity were investigated by sampling fruit bodies of polyporoid and corticioid fungi in forest stands that have different management histories. Fruit bodies were sampled in 15 northern hardwood stands in northern Wisconsin and the upper peninsula of Michigan. Sampling was conducted in five old-growth stands, five uneven-age...

  8. A Comparison of Several Artificial Neural Network Classifiers for CT Images of Hardwood Logs (United States)

    Daniel L. Schmoldt; Jing He; A. Lynn Abbott


    Knowledge of internal log defects, obtained by scanning, is critical to efficiency improvements for future hardwood sawmills. Nevertheless, before computed tomography (CT) scanning can be applied in industrial operations, we need to automatically interpret scan information so that it can provide the saw operator with the information necessary to make proper sawing...

  9. Stand and individual tree growth response to treatments in young natural hardwoods (United States)

    Daniel J. Robison; Tracy San Filipo; Charlie Lawrence III; Jamie L. Schuler; Bryan J. Berenguer


    Young even-aged upland Piedmont mixed hardwood and pine stands were treated with a variety of fertilizer and release (competition control) treatments. The sites studied are on the NC State University Hill Demonstration Forest in central North Carolina, and are characterized by formerly highly eroded agricultural sites (Richter et al. 2000) now in their third rotation...

  10. Survival of Hardwood Regeneration During Prescribed Fires: The Importance of Root Development and Root Collar Location (United States)

    Patrick Brose; David Van Lear


    Fire ecology studies in eastern hardwood forests usually use plot-based inventory methods and focus on sprouting stems to detect changes in vegetative composition and structure. Rarely are individual stems studied and stems that fail to sprout are usually ignored. In this study, an individual stem mortality approach was employed. Four hundred fifty stems of eight...

  11. In vitro propagation of tropical hardwood tree species — A review (2001-2011) (United States)

    Paula M. Pijut; Rochelle R. Beasley; Shaneka S. Lawson; Kaitlin J. Palla; Micah E. Stevens; Ying. Wang


    Tropical hardwood tree species are important economically and ecologically, and play a significant role in the biodiversity of plant and animal species within an ecosystem. There are over 600 species of tropical timbers in the world, many of which are commercially valuable in the international trade of plywood, roundwood, sawnwood, and veneer. Many of these tree...

  12. Assessing the feasibility and profitability of cut-to-length harvests in eastern hardwoods (United States)

    Chris B. LoDoux


    Cut-to-length (CTL) logging applications are becoming more popular in hardwood forests. CTL harvesting causes much less damage to the residual stand than conventional harvesting because logs and trees are not pulled through the stand and trees can be felled directionally.

  13. Modeling and simulating two cut-to-length harvesting systems in central Appalachian hardwoods (United States)

    Jingxin Wang; Chris B. LeDoux; Yaoxiang Li


    The production rates and costs of two cut-to-length harvesting systems was simulated using a modular ground-based simulation model and stand yield data from fully stocked, second growth even aged central Appalachian hardwood forests. The two harvesters simulated were a modified John Deere 988 tracked excavator with a model RP 1600 single grip sawhead and an excavator...

  14. Productivity and cost of manual felling and cable skidding in central Appalachian hardwood forests (United States)

    Jingxin Wang; Charlie Long; Joe McNeel; John Baumgras; John Baumgras


    A field production study was conducted for a manual harvesting system using a chainsaw and cable skidder in a central Appalachian hardwood forest site. A partial cut was performed on a 50-acre tract with an average slope of 25 percent. Felling time pre tree was most affected by diameter at breast height and the distance between harvested trees while skidding cycle time...

  15. Production economics of harvesting small-diameter hardwood stands in central Appalachia (United States)

    Yaoxiang Li; Jingxin Wang; Gary Miller; Joe McNeel


    Three harvesting systems of chainsaw/cable skidder, feller-buncher/grapple skidder, and harvester/forwarder were simulated in harvesting three hardwood stands 30 to 50 years old in central Appalachia. Stands were generated by using a 3D stand generator. Harvesting prescriptions included clearcut, shelterwood cut, selective cut, diameter limit cut, and crop tree release...

  16. Regeneration after cutting of old-growth northern hardwoods in New Hampshire (United States)

    William B. Leak; Robert W., Jr. Wilson


    Past experience with cuttings in old-growth northern hardwoods has demonstrated that the primary regeneration problem is to obtain a large proportion of desirable species of good quality. Regardless of method or intensity of cutting, the total amount of reproduction usually is adequate. Second-growth stands are a different story: this report pertains only to old-growth...

  17. Long-term effects of single prescribed fires on hardwood regeneration in oak shelterwood stands (United States)

    Patrick H. Brose


    One of the arguments against using prescribed fire to regenerate oak (Quercus spp.) forests is that the improvement in species composition of the hardwood regeneration pool is temporary and multiple burns are necessary to achieve and maintain oak dominance. To explore this concern, I re-inventoried a prescribed fire study conducted in the mid-1990s...

  18. Hardwoods for timber bridges : a national program emphasis by the USDA Forest Service (United States)

    James P. Wacker; Ed Cesa


    This paper describes the joint efforts of the Forest Service and the FHWA to administer national programs including research, demonstration bridges, and technology transfer components. Summary information on a number of Forest Service-WIT demonstration bridges constructed with hardwoods is also provided.

  19. Radial growth of hardwoods following the 1998 ice storm in New Hampshire and Maine (United States)

    Kevin T. Smith; Walter C. Shortle


    Ice storms and resulting injury to tree crowns occur frequently in North America. Reaction of land managers to injury caused by the regional ice storm of January 1998 had the potential to accelerate the harvesting of northern hardwoods due to concern about the future loss of wood production by injured trees. To assess the effect of this storm on radial stem growth,...

  20. Resistance is not futile: The response of hardwoods to fire-caused wounding (United States)

    Elaine Kennedy Sutherland; Kevin Smith


    Fires wound trees; but not all of them, and not always. Specific fire behavior and differences among tree species and individual trees produce variable patterns of wounding and wound response. Our work focuses on the relationships between fire behavior and tree biology to better understand how hardwood trees resist injury to the lower stem and either survive or succumb...

  1. Characterizing the adoption of low-grade hardwood lumber by the secondary wood processing industry (United States)

    Robert L. Smith; Wibke Pohle; Philip Araman; Dan Cumbo


    This study investigated the adoption of low-grade lumber in the secondary hardwood industry. Factors influencing decisions regarding the utilization of low-grade lumber were identified and value-added opportunities to increase the use of low-grade lumber among manufacturers currently using higher grades were evaluated. Data were collected via a nationwide mail survey...

  2. Tangential scanning of hardwood logs: developing an industrial computer tomography scanner (United States)

    Nand K. Gupta; Daniel L. Schmoldt; Bruce Isaacson


    It is generally believed that noninvasive scanning of hardwood logs such as computer tomography (CT) scanning prior to initial breakdown will greatly improve the processing of logs into lumber. This belief, however, has not translated into rapid development and widespread installation of industrial CT scanners for log processing. The roadblock has been more operational...

  3. Predicting the regeneration of Appalachian hardwoods: adapting the REGEN model for the Appalachian Plateau (United States)

    Lance A. Vickers; Thomas R. Fox; David L. Loftis; David A. Boucugnani


    The difficulty of achieving reliable oak (Quercus spp.) regeneration is well documented. Application of silvicultural techniques to facilitate oak regeneration largely depends on current regeneration potential. A computer model to assess regeneration potential based on existing advanced reproduction in Appalachian hardwoods was developed by David...

  4. Fifteen-Year Growth of Six Planted Hardwood Species on Sharkey Clay Soil (United States)

    Roger M. Krinard; Harvey E. Kennedy


    Six hardwood species planted on Sharkey clay soil that had been disked the first 5 years for weed control were significantly taller at age 5 when compared to species grown on mowed sites. By age 15, there were no differences in heights within species except for sweet pecan. Average heights by species at age 15 were: cottonwood (Populus deltoides...

  5. The Number of Hardwood Sawmills Continues to Decrease - Is that Bad? (United States)

    William G. Luppold; William G. Luppold


    The following Guest Editorial, "The Number of Hardwood Sawmills Continues to Decrease - Is that Bad?" is presented by William G. Luppold, Ph.D., of the USDA Forest Service Northeastern Research Station - Forestry Sciences Laboratory. In this article, Dr. Luppold examines many of the key issues surrounding the size and loss of sawmills, which has influenced...

  6. The sine method as a more accurate height predictor for hardwoods (United States)

    Don C. Bragg


    Most hypsometers apply a mathematical technique that utilizes the tangent of angles and a horizontal distance to deliver the exact height of a tree under idealized circumstances. Unfortunately, these conditions are rarely met for hardwoods in the field. A “new” predictor based on sine and slope distance and discussed here does not require the same assumptions for...

  7. Impact of product mix and markets on the economic feasibility of hardwood thinning (United States)

    John E. Baumgras; Chris B. LeDoux


    Results demonstrate how the economic feasibility of commercial hardwood thinning is impacted by tree diameter, product mix, and primary product markets. These results indicate that multiproduct harvesting can increase revenues by $0.01/ft³ to $0.32/ft³; and that small shifts in price levels or haul distance can postpone commercial thinning...

  8. Analysis of harvesting opportunities for thinning eastern hardwoods on steep terrain (United States)

    Chris B. LeDoux; John E. Baumgras


    Harvesting cost and revenue models were used to evaluate yarding costs by yarder type and to compare stump-to-mill harvesting costs to revenues available from multiproduct thinnings in eastern hardwoods. This analysis includes six types of cable yarders and thinnings in stands where the average diameter at breast height of trees harvested ranged from 7 to 12 inches. To...

  9. Preliminary Full-Scale Tests of the Center for Automated Processing of Hardwoods' Auto-Image (United States)

    Philip A. Araman; Janice K. Wiedenbeck


    Automated lumber grading and yield optimization using computer controlled saws will be plausible for hardwoods if and when lumber scanning systems can reliably identify all defects by type. Existing computer programs could then be used to grade the lumber, identify the best cut-up solution, and control the sawing machines. The potential value of a scanning grading...

  10. Consumer and manufacturer perceptions of hardwood panels made from character-marked lumber (United States)

    D. Nicholls; M. Bumgardner; V. Barber


    Hardwood panels made from edge-glued material are a versatile product that could be within the reach of many smaller wood products firms. However, products would need to be accepted throughout the supply chain for this opportunity to be achieved. This study evaluated preferences of consumers and manufacturers towards edge-glued panels from Alaskan red alder and paper...

  11. Leaf fall, humus depth, and soil frost in a northern hardwood forest (United States)

    George Hart; Raymond E. Leonard; Robert S. Pierce


    In the mound-and-depression microtopography of the northern hardwood forest, leaves are blown off the mounds and collect in the depressions. This influence of microtopography on leaf accumulation is responsible for much of the variation in humus depth; and this, in turn, affects the formation and depth of soil frost.

  12. SITEQUAL--A User's Guide: Computerized Site Evaluation for 14 Southern Hardwood Species (United States)

    Constance A. Harrington; Bettina M. Casson


    An interactive computer program, SITEQUAL, has been developed from the widely-used Baker and Broadfoot field guides, which evaluate site quality for 14 southern hardwood tree species. The SITEQUAL program calculates site index for all species simultaneously and provides a breakdown of site index into the component contributions by each of the four major soil factors...

  13. Rationale and Application of Tangential Scanning to Industrial Inspection of Hardwood Logs (United States)

    Nand K. Gupta; Daniel L. Schmoldt; Bruce Isaacson


    Industrial computed tomography (CT) inspection of hardwood logs has some unique requirements not found in other CT applications. Sawmill operations demand that large volumes of wood be scanned quickly at high spatial resolution for extended duty cycles. Current CT scanning geometries and commercial systems have both technical and economic [imitations. Tangential...

  14. Influence of Lumber Volume Maximization on Value in Sawing Hardwood Sawlogs (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman


    Research based on applying volume-maximizing sawing solutions to idealized hardwood log forms has shown that average lumber yield can be increased by 6 percent. It is possible, however, that a lumber volume-maximizing solution may result in a decrease in lumber grade and a net reduction in total value of sawn lumber. The objective of this study was to determine the...

  15. The Value Versus Volume Yield Problem for Live-Sawn Hardwood Sawlogs (United States)

    Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman


    The potential conflict between value and volume maximization in sawing hardwood sawlogs by the live sawing method was analyzed. Twenty-four digitally described red oak sawlogs were sawn at the log orientation of highest value yield. Five opening face sawlines were iteratively placed in the sawlog a 1/4-inch intervals and lumber grades, volumes, and values from...

  16. Hardwood supply chain and the role of log brokers in 2012 (United States)

    Iris Montague; Adrienn Andersch; Jan Wiedenbeck; Urs. Buehlmann


    The recent economic crisis has greatly affected how companies conduct business. To be competitive, companies had to make changes to their product lines, distribution channels, marketing, and overall business strategies. This study was conducted to describe and analyze the log supply component of the hardwood forest products distribution chain and to investigate changes...

  17. The international hardwood lumber market and potential impacts on your bottom line (United States)

    Bill Luppold; Matthew. Bumgardner


    Even if you don't sell logs or lumber to foreign customers, the international hardwood market can impact your business in significant ways, and smart business leaders are taking notice so that they are ready for shifting market impacts. Many people believe that lumber exporting is only an opportunity for larger sawmills. However, even if you have a portable mill...

  18. Use of Hardwood Tree Species by Birds Nesting in Ponderosa Pine Forests (United States)

    Kathryn L. Purcell; Douglas A. Drynan


    We examined the use of hardwood tree species for nesting by bird species breeding in ponderosa pine (Pinus ponderosa) forests in the Sierra National Forest, California. From 1995 through 2002, we located 668 nests of 36 bird species nesting in trees and snags on four 60-ha study sites. Two-thirds of all species nesting in trees or snags used...

  19. Effects of winter flooding on mass and gross energy of bottomland hardwood acorns (United States)

    Alan G. Leach; Jacob N. Straub; Richard M. Kaminski; Andrew W. Ezell; Tracy S. Hawkins; Theodor D. Leininger


    Decomposition of red oak acorns (Quercus spp.; Section Erythrobalanus) could decrease forage biomass and gross energy (GE) available to wintering ducks from acorns. We estimated changes in mass and GE for 3 species of red oak acorns in flooded and non-flooded bottomland hardwood forests in Mississippi during winter 2009–2010. Mass...

  20. Using low-grade hardwoods for CLT production: a yield analysis (United States)

    R. Edward Thomas; Urs. Buehlmann


    Low-grade hardwood logs are the by-product of logging operations and, more frequently today, urban tree removals. The market prices for these logs is low, as is the value recovered from their logs when producing traditional forest products such as pallet parts, railroad ties, landscaping mulch, or chips for pulp. However, the emergence of cross-laminated timber (CLT)...