Biomechanical pulping of spruce wood chips with Streptomyces cyaneus CECT 3335 and handsheet characterization

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 173-177 ◽  
Author(s):  
Manuel Hernández ◽  
M. Jesus Hernández-Coronado ◽  
M. Isabel Pérez ◽  
Esteban Revilla ◽  
Juan C. Villar ◽  
...  
Keyword(s):  
Lignin Content ◽  
Middle Lamella ◽  
Treated Wood ◽  
Strength Properties ◽  
Wood Chips ◽  
Fiber Network ◽  
Spruce Wood ◽  
Gradual Loss ◽  
Acid Soluble Lignin ◽  
Streptomyces Cyaneus

AbstractThe actinobacteriumStreptomyces cyaneusCECT 3335 was evaluated for its ability to delignify spruce wood chips (Picea abies) after 2 weeks of incubation prior to refiner mechanical pulping. Weight loss of the chips during the treatment ranged from 2% to 3%. Chemicalanalysis of the treated wood showed an increase in acid-soluble lignin content concomitant with a notable increase in the acid/aldehyde+ketone [AC/(AL+KE)] ratio of the lignin compared with the control. Structural alterations in wood cell walls were observed by optical and scanning microscopy using astra blue-safranin staining and cryosections stained with gold/palladium, respectively. A gradual loss of lignin from the lumen towards the middle lamella and incipient defiberization could be observed. The estimation of specific energy for the defibration and refining stages of treated pulp showed a 24% reduction in the energy required, largely due to a 30% saving in the defibration of chips. The analysis of handsheets obtained from treated pulp showed a notable improvement in some strength properties, such as breaking length, tear index and stretch. In addition, the high Gurley air resistance value indicates more packing of the voids of the fiber network. These results demonstrate for the first time the suitability ofStreptomyces cyaneusfor biomechanical pulping purposes.

Inhomogeneities in the Chemical Structure of Hardwood Lignins

Holzforschung ◽  
2003 ◽  
Vol 57 (3) ◽  
pp. 255-265 ◽  
Author(s):  
H. Önnerud ◽  
G. Gellerstedt
Keyword(s):  
Secondary Wall ◽  
Lignin Content ◽  
Middle Lamella ◽  
Size Exclusion ◽  
Wall Material ◽  
Thermomechanical Pulp ◽  
Aryl Ether ◽  
Spruce Wood ◽  
Exclusion Chromatography ◽  
The Difference

Summary Bauer-McNett fractions of an aspen chemi-thermomechanical pulp showed a significant variation with respect to lignin content and sugar composition, and two of the fractions were found to be particularly rich in middle lamella and secondary wall material, respectively. The secondary wall lignin of aspen was found to contain larger amounts of non-condensed β-O-4 aryl ether structures than the middle lamella lignin and the difference was attributed to a larger amount of syringyl structures as revealed by thioacidolysis. Size exclusion chromatography of the thioacidolysis products from birch and spruce wood showed a larger part of lignin oligomers being present in the degraded spruce lignin. Moreover, birch lignin had a lower phenolic content than both aspen and spruce lignin. Thioacidolysis followed by Raney-nickel desulphuration was used for the analysis of hardwood lignin trimers.

scholarly journals Degradation of thermo-hygro-mechanically (THM)-densified wood by soft-rot fungi

Holzforschung ◽  
2008 ◽  
Vol 62 (3) ◽  
Author(s):  
Oleksandr Skyba ◽  
Peter Niemz ◽  
Francis W.M.R. Schwarze
Keyword(s):  
Lignin Content ◽  
Beech Wood ◽  
Treated Wood ◽  
Untreated Wood ◽  
Soft Rot ◽  
Saturated Steam ◽  
Densified Wood ◽  
Microscopical Examination ◽  
Weight Losses ◽  
Spruce Wood

Abstract Thermo-hygro-mechanical (THM)-densified wood is more resistant to colonisation and degradation by brown-rot fungi than untreated wood. Colonisation and degradation by soft-rot fungi was investigated in treated Norway spruce (Picea abies) and treated beech (Fagus sylvatica) to assess their suitability for utility class 4. Three different treatments were applied: thermal-hygro (TH) treatment, mechanical densification and THM-treatment including densification and post-treatment under saturated steam conditions at different temperatures. For comparison, additional wood specimens were treated with two concentrations of a chromium-copper (CC) wood preservative. After 32 weeks incubation, weight losses induced by soft-rot fungi were lowest in wood treated with CC. Highest weight losses were recorded from TH-treated wood, in which soft-rot erosion attack (type 2) was exclusively observed in spruce. In comparison to controls, significantly lower weight losses by soft-rot fungi were recorded in THM-treated spruce wood, but no such differences were found in beech wood. Microscopical examination showed that in THM-treated wood of spruce, soft-rot type 1 commenced from the outer wood surfaces and cavity formation was not found in deeper regions of the wood samples. THM-treated beech wood was more susceptible to degradation than that of spruce which can be partly explained by the higher syringyl lignin content in beech wood, which is more susceptible to all kinds of degradation. Hyphal colonisation and soft-rot was facilitated within deeper regions of beech wood mainly in the non-occluded lumina of parenchyma cells in multiseriate xylem rays. It can be concluded that TH-treated spruce wood and THM-treated beech wood is susceptible to soft-rot and therefore inappropriate for utility class 4.

scholarly journals Xylanase pretreatment of mechanically destructured chips of Eucalyptus tereticornis and its effect on kraft pulping

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5361-5375
Author(s):  
Laxman Kumar Pandey ◽  
Amit Kumar ◽  
Surendra Pal Singh ◽  
Dharm Dutt
Keyword(s):  
Treated Wood ◽  
Untreated Wood ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Wood Chips ◽  
Pulp Yield ◽  
Physical Strength ◽  
Cooking Temperature ◽  
Combined Pretreatment

Mechanical pulping of raw wood material is a highly energy intensive and pollution generating step in the papermaking process. This study focused on combined mechanical and xylanase treatment prior to the kraft pulping of E. tereticornis. A screened pulp yield of 49.1% (on oven-dry wood basis) with a Kappa number of 24.9 was obtained at the optimum cooking temperature of 160 °C without any pretreatment of the wood chips. After mechanical treatment (destructuring), a slightly higher screened pulp yield (49.4%) was obtained with a Kappa number of 24.2 at the cooking temperature of 145 °C with the same active alkali charge (15%). The optimum cooking temperature was further reduced to 140 °C for the destructured xylanase-treated wood chips. The xylanase treatment resulted in a 2% reduction in screened pulp yield due to hydrolysis of xylan. However, the Kappa number was reduced to 18.2 after xylanase pretreatment of the mechanically destructured wood chips. The combined pretreatment (destructured and xylanase treatment) of wood chips resulted in a reduction in cooking temperature by 20°C compared to untreated wood chips. Such a reduction in cooking temperature can effectively reduce steam consumption. The combined pretreatment improved the pulp brightness by 2.0 (ISO points) and physical strength properties, which included the tensile index, tear index, and burst index by 11.06%, 21.72%, and 21.79%, respectively, compared to the control.

The topochemistry of black spruce sulphonation: A TEM/EDXA study

1983 ◽  
Vol 41 ◽  
pp. 710-711
Author(s):  
R.P. Beatson ◽  
C. Gancet ◽  
C. Heitner
Keyword(s):  
Cell Wall ◽  
Significant Influence ◽  
Background Subtraction ◽  
Black Spruce ◽  
Middle Lamella ◽  
Wood Chips ◽  
Factors Affecting ◽  
X Ray ◽  
Spruce Wood ◽  
Carbon Coated

Pulps produced by mechanical defibration of sulphite treated black spruce wood chips contain large amounts of lignin. The degree of sulphonation of this lignin has a significant influence on the physical properties of handsheets made from the resulting pulps In earlier work we have described the factors affecting the sulphonation of black spruce.The aim of the present investigation was to determine the differences in reactivity of sulphite towards lignin in the middle lamella and cell wall of black spruce.Black spruce wood chips were well impregnated with sodium base sulphite solutions having pH 7, and then heated at 140° and 80°C for known times. The resulting sulphonated wood chips were cut into small sticks and embedded in Vestopal. Transverse sections, 150 nm thick, were placed on a carbon grid having a single 1 mm hole bearing a collodian film which had been carbon coated. Sulphur contents in the middle lamella and cell wall were determined with a Philips 400 TEM coupled with an EDAX 9100/60 analyser. The concentration of sulphur was taken to be proportional to the x-ray counts in the sulphur Kα window after background subtraction, as shown in Figure 1.

Lignin chemistry and topochemistry during kraft delignification of Eucalyptus globulus genotypes with contrasting pulpwood characteristics

Holzforschung ◽  
2014 ◽  
Vol 68 (6) ◽  
pp. 623-629 ◽  
Author(s):  
María Graciela Aguayo ◽  
André Ferraz ◽  
Juan Pedro Elissetche ◽  
Fernando Masarin ◽  
Regis Teixeira Mendonça
Keyword(s):  
Chemical Composition ◽  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Middle Lamella ◽  
Kraft Pulping ◽  
Pulp And Paper ◽  
Wood Chips ◽  
Short Fibre ◽  
Paper Production ◽  
Cell Corner

Abstract Eucalyptus globulus Labill. is a short-fibre resource for pulp and paper production. Ten different E. globulus genotypes with varied pulpwood quality and chemical composition were evaluated under kraft pulping conditions. Characterisation of the wood and pulp samples by thioacidolysis indicated that the content of syringyl units in β-O-4 linkages (S-β-O-4) was distinct for the studied genotypes. The highest S-β-O-4 levels were detected in the samples with the lowest original lignin and highest glucan levels. This group of samples provided the pulps with the lowest final lignin content at higher yields. UV microspectrophotometric (UMSP) evaluation of the wood chips revealed that the samples with the lowest lignin levels have the lowest UV absorbances at 278 nm (A278 nm) in the secondary walls (S2). During kraft pulping, lignin from the S2 was dissolved, whereas lignins from the middle lamella and cell corner lignin was not removed not even for prolonged reaction periods, independently of the evaluated genotype. The A278 nm values of the S2 were significantly lower in the pulps from the genotypes with less original lignin content.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

scholarly journals Treatment of wood with atmospheric plasma discharge: study of the treatment process, dynamic wettability and interactions with a waterborne coating

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jure Žigon ◽  
Matjaž Pavlič ◽  
Pierre Kibleur ◽  
Jan Van den Bulcke ◽  
Marko Petrič ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Treatment Process ◽  
Beech Wood ◽  
Treated Wood ◽  
Plasma Discharge ◽  
Contact Angles ◽  
Atmospheric Plasma ◽  
Waterborne Coating ◽  
Spruce Wood ◽  
The Impact

AbstractPlasma treatment is becoming a mature technique for modification of surfaces of various materials, including wood. A better insight in the treatment process and the impact of the plasma on properties of wood bulk are still needed. The study was performed on Norway spruce and common beech wood, as well as their thermally modified variations. The formations of the airborne discharge, as well as mass changes of the treated wood, were monitored. The impact of such treatment on wood-coating interaction was investigated by evaluating the dynamic wettability and penetration into wood. At the wood surface, plasma streamers were observed more intense on denser latewood regions. Wood mass loss was higher with increasing number of passes through the plasma discharge and was lower for thermally modified wood than for unmodified wood. Plasma treatment increased the surface free energy of all wood species and lowered the contact angles of a waterborne coating, these together indicating enhanced wettability after treatment. Finally, the distribution and penetration depth of the coating were studied with X-ray microtomography. It was found that the coating penetrated deeper into beech than into spruce wood. However, the treatment with plasma increased the penetration of the coating only into spruce wood.

scholarly journals Bacterial Biodegradation of Extractives and Patterns of Bordered Pit Membrane Attack in Pine Wood

2000 ◽  
Vol 66 (12) ◽  
pp. 5201-5205 ◽  
Author(s):  
Todd A. Burnes ◽  
Robert A. Blanchette ◽  
Roberta L. Farrell
Keyword(s):  
Xanthomonas Campestris ◽  
Treated Wood ◽  
Wood Chips ◽  
Pulp Mills ◽  
Wood Extractives ◽  
Bordered Pit ◽  
Pine Wood ◽  
Pit Membrane ◽  
Pine Wood Chips ◽  
Ray Parenchyma Cells

ABSTRACT Wood extractives, commonly referred to as pitch, cause major problems in the manufacturing of pulp and paper. Treatment of nonsterile southern yellow pine chips for 14 days withPseudomonas fluorescens, Pseudomonas sp.,Xanthomonas campestris, and Serratia marcescens reduced wood extractives by as much as 40%. Control treatments receiving only water lost 11% of extractives due to the growth of naturally occurring microorganisms. Control treatments were visually discolored after the 14-day incubation, whereas bacterium-treated wood chips were free of dark staining. Investigations using P. fluorescens NRRL B21432 showed that all individual resin and fatty acid components of the pine wood extractives were substantially reduced. Micromorphological observations showed that bacteria were able to colonize resin canals, ray parenchyma cells, and tracheids. Tracheid pit membranes within bordered pit chambers were degraded after treatment with P. fluorescensNRRL B21432. P. fluorescens and the other bacteria tested appear to have the potential for biological processing to substantially reduce wood extractives in pine wood chips prior to the paper making process so that problems associated with pitch in pulp mills can be controlled.

Strength properties of black spruce wood under different treatment

1996 ◽  
Vol 30 (6) ◽  
Author(s):  
Katerina Kwasniakova ◽  
BohuslavV. Kokta ◽  
Zoltan Koran
Keyword(s):  
Black Spruce ◽  
Strength Properties ◽  
Spruce Wood

Lignin distribution in waterlogged archaeological Picea abies (L.) Karst degraded by erosion bacteria

Holzforschung ◽  
2014 ◽  
Vol 68 (7) ◽  
pp. 791-798 ◽  
Author(s):  
Nanna Bjerregaard Pedersen ◽  
Uwe Schmitt ◽  
Gerald Koch ◽  
Claus Felby ◽  
Lisbeth Garbrecht Thygesen
Keyword(s):  
Picea Abies ◽  
Lignin Content ◽  
Middle Lamella ◽  
Uv Absorbance ◽  
Tem Analysis ◽  
Lignin Distribution ◽  
Transmission Electron ◽  
Residual Material ◽  
Ray Parenchyma Cells ◽  
Very High

Abstract The lignin distribution in poles of waterlogged archaeological Picea abies (L.) Karst, which was decayed by erosion bacteria (EB) under anoxic conditions for approximately 400 years, was topochemically identified by transmission electron microscopy (TEM) and high resolution UV-microspectrophotometry (UMSP). Lignin rich cell wall compartments such as cell corner (CC), compound middle lamella (CML), torus, initial pit border and mild compression wood (CW) appeared morphologically well preserved together with S1 and S3 layers and epithelial and ray parenchyma cells. Residual material (RM) from degraded S2 showed a varied lignin distribution as evidenced by the different local UV-absorbance intensities. However, evaluation of UV-absorbance line spectra of RM revealed no change in conjugation of the aromatic ring system. Presence of RM with both very low and very high lignin absorbances showed evidence for disassembly of lignin during degradation combined with aggregation of lignin fragments and physical movement of these fractions. In contrast to TEM analysis, locally decreasing lignin content was found by UMSP in CML regions.

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