Pentosan Extraction from Poplar Treated by Green Liquid

2013 ◽  
Vol 724-725 ◽  
pp. 399-404
Author(s):  
Jun Ying Zhang ◽  
Jing Hui Zhou ◽  
Hai Ming Li ◽  
Ying Han ◽  
Jun Feng Shi
Keyword(s):  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Green Liquor ◽  
The Third ◽  
Yield Level ◽  
Lower Viscosity ◽  
Pretreatment Conditions ◽  
Material Temperature ◽  
Process Liquor

Green liquor, a process liquor of alkali recovery in pulp and papermaking industry, pretreatment used in poplar kraft pulping process and the influences of pretreatment conditions on pentosan extraction have been studied. The results show that the influence of green liquor dosage on pentosan extraction is the most remarkable, with temperature taking the second place and time the third. Under the conditions of liquor ratio 1:4, green liquor dosage 1.5 L/kg (based on oven dried material), temperature 100 °C, time 90 min, higher pentosan extraction ratio of 13.81% (based on the pentosan content of raw material) is achieved. The wood was pulped under normal KP conditions after pretreated by the optimal pentosan extraction conditions. Comparing two kinds of pulp with and without pretreatment at similar stock yield level, the results show that the former has a little lower viscosity, significantly decreased Kappa number and excellent paper physical properties.

Pretreatment Optimization of Poplar Green Liquor Pretreatment-Kraft Pulping

2013 ◽  
Vol 781-784 ◽  
pp. 2654-2657
Author(s):  
Xiao Hong Chen ◽  
Guang Wei Sun ◽  
Jing Hui Zhou ◽  
Ying Han
Keyword(s):  
Process Parameters ◽  
Kraft Pulping ◽  
Holding Time ◽  
Green Liquor ◽  
Liquor Ratio ◽  
Pretreatment Temperature ◽  
Pretreatment Conditions

Green liquor has lower hydroxide concentration and higher sulfidity, which makes it a better choice for modified alkali cooking. This paper studied process parameters of pretreatment stage on pulping properties of poplar green liquor pretreatment-Kraft pulping process. Conditional experiments with green liquor charge of 0.50L/kg, 0.75L/kg, 1.00L/kg and 1.25L/kg, maximum pretreatment temperature of 95°C, 105°C, 115°C and 135°C, and holding time of 30min, 60min and 90min, were carried out. The results shows that optimal pretreatment conditions are as follows: green liquor charge, 1.00L/kg; maximum pretreatment temperature, 115°C; holding time, 60min; and wood to liquor ratio, 1:4.

Target Kappa Number for AS/AQ Pulping of Wheat Straw

2011 ◽  
Vol 236-238 ◽  
pp. 1431-1436
Author(s):  
Jing Liu ◽  
Katsuya Nagata
Keyword(s):  
Mass Transfer ◽  
Wheat Straw ◽  
Transition Point ◽  
Phase Transfer ◽  
Raw Materials ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Experimental Results ◽  
Raw Material ◽  
Pulp Yield

Alkaline sulfite/anthraquinone (AS/AQ) pulping of wheat straw under different conditions was conducted in this study. A transition point of kappa number at approximately 6.5 was observed based on all experimental results. This transition point can be regarded as the phase transfer point in AS/AQ pulping from bulk to residual delignification. Effective delignification without great lost of pulp yield can be achieved before kappa number was below this transition point during AS/AQ pulping of wheat straw. It is found that the ratio of cooking liquid to solid should not be lower than 6, if good mass transfer of chemicals and lignin dissolving is needed. As the ratio of Na2SO3 to NaOH dosage ranged from 0.4 to 2.4, low proportion of Na2SO3 allows effective delignification while no serious degradation of carbohydrate. Moreover, similar to kraft pulping, addition of AQ in the range of 0.05% to 0.25% is useful to remove lignin and protect the carbohydrate during AS/AQ pulping. Finally, although the transition point of kappa number may be changed while different raw material used for same pulping process or different pulping process for same raw materials, it is of interest and important for mill practice.

scholarly journals Technological evaluation of Pinus maximinoi wood for industrial use in kraft pulp production

TAPPI Journal ◽  
2021 ◽  
Vol 20 (8) ◽  
pp. 501-508
Author(s):  
MARINA ULIAN COELHO ◽  
FRANCIDES GOMES DA SILVA, JR. ◽  
FLAVIANA REIS MILAGRES ◽  
SILVANA MEISTER SOMMER ◽  
CARLOS AUGUSTO SOARES DO AMARAL ◽  
...  
Keyword(s):  
Process Analysis ◽  
Black Liquor ◽  
Basic Density ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Bulk Property ◽  
Oxygen Delignification ◽  
Old Trees ◽  
Pulp Production

This study characterized Pinus maximinoi wood and evaluated its performance for pulp production. Samples of Pinus taeda wood were used as reference material. For both species, wood chips from 14-year-old trees were used for the technological characterization, pulping, bleaching process analysis, and pulp properties. A modified kraft pulping process was carried out targeting kappa number 28±5% on brownstock pulp. The bleaching sequence was applied for bleached pulp with final brightness of 87±1 % ISO. Refinability and resistance properties were measured in the bleached pulps. Compared to P. taeda wood, P. maximinoi showed slightly higher basic density (0.399 g/cm³) and higher holocellulose (64.5%), lignin (31.1%), and extractives content (4.5%), along with lower ash content (0.16%). P. maximinoi tracheids showed greater wall thickness (6.4 µm) when compared to P. taeda tracheids. For the same kappa number, P. maximinoi and P. taeda resulted in similar screened yield, with an advantage observed for P. maximinoi, which resulted in lower specific wood consumption (5.281 m³/o.d. metric ton), and lower black liquor solids (1.613 metric tons/o.d. metric ton). After oxygen delignification, P. maximinoi pulp showed higher efficiency on kappa reduction (67.2%) and similar bleaching chemical demand as P. taeda pulp. Compared to P. taeda pulps, the refined P. maximinoi pulps had similar results and the bulk property was 10% higher. Results showed that P. maximinoi is an interesting alternative raw material for softwood pulp production in Brazil.

Comparison between Green Liquor Pretreatment-Kraft Pulping and Conventional Kraft Pulping

2013 ◽  
Vol 781-784 ◽  
pp. 2650-2653
Author(s):  
Zhang Hong Xie ◽  
Jing Hui Zhou ◽  
Hai Ming Li ◽  
Guang Wei Sun
Keyword(s):  
Kraft Pulp ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Green Liquor ◽  
Pulp Strength

This paper studied the differences of pulping performances, beating characteristics and strength properties between green liquor pretreatment-Kraft pulping and conventional Kraft pulping based on previous optimized pulping conditions. The green liquor pretreatment-Kraft pulping has higher yield, lower Kappa number, reduced residual effective alkali and decreased viscosity. Green liquor pretreatment improves pulp strength properties although green liquor pretreatment-Kraft pulp has beating characteristics similar to conventional Kraft pulp.

Reed Soda Pulping Modified by Green Liquor Pretreatment

2013 ◽  
Vol 781-784 ◽  
pp. 2628-2631
Author(s):  
Yi Jia Sun ◽  
Hai Ming Li ◽  
Jing Hui Zhou ◽  
Guang Wei Sun ◽  
Zhang Hong Xie
Keyword(s):  
Kappa Number ◽  
Holding Time ◽  
Practical Significance ◽  
Maximum Temperature ◽  
Green Liquor ◽  
Liquor Ratio ◽  
Soda Pulping ◽  
Pretreatment Conditions ◽  
Heating Up

The soda pulping modified by green liquor pretreatment was adopted to explore optimal green liquor pretreatment conditions. Results shows that optimum pretreatment conditions are as follows: max temperature, 130°C; holding time, 90min; wood to liquor ratio, 1:4; and green liquor charge, 0.9L/kg. Pretreated reed was pulped under following conditions: heating-up time, 60min; maximum temperature, 160°C; holding time, 60min; NaOH charge, 20% (pretreatment alkali included). Results shows that this process produces pulp with screened yield of 49.05%, Kappa number of 14.6, and viscosity of 1274mL/g. Compared with the results of industrial simulation pulping (21% NaOH), screened yield increases by 2.14%, Kappa number decreases by 5.6 and viscosity rises by 556 mL/g. Therefore, green liquor pretreatment before soda pulping improves pulp performance and yield. Meanwhile the pretreatment utilizes material effectively, thus has practical significance to decrease alkaline consumption and pulping cost.

Research on Kraft Pulping Delignification of Bamboo (Neosinocalamus)

2011 ◽  
Vol 418-420 ◽  
pp. 2241-2244
Author(s):  
Pei Yi Li ◽  
Mei Yun Zhang ◽  
Xin Xing Xia ◽  
Chun Tao Lin
Keyword(s):  
Fiber Material ◽  
Wide Distribution ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Maximum Temperature ◽  
Pulp Yield ◽  
Oxygen Delignification ◽  
Local Conditions ◽  
Bamboo Pulp

Bamboo, as a kind of non-wood raw material, has a long, thin fiber with wide distribution and rich abundance in China. Its pulping properties are between softwood and hardwood. Adapting to the Chinese situation, developing bamboo pulp industrialization, according to the local conditions, is an available way to solve the shortage of fiber material for paper-making. Delignification of bamboo (Neosinocalamus) was carried out by conventional kraft and soda pulping under varying conditions to determine the relationships between selected cooking parameters (EA 14~20%, sulfidity 0~40%, maximum temperature 160 and 165°C, and time at maximum temperature 60~110 min) and pulp properties (kappa number and yield). Results indicated that in order to obtain relatively low kappa numbers(17~27), high sulfidity(20~40%) at lower EA(14~16%) increased pulp yield compared to the case of low sulfidity(0~10%) at higher EA(16~18%). Pulp with lower kappa numbers (13~15) and acceptable yield can be obtained at a sulfidity level of 20~30% with 18% EA or at a sulfidity level of 10~30% with 20% EA. Meanwhile, bamboo pulp in this condition not only helps to decrease kappa number in the subsequent oxygen delignification process, but also reduces the cost of chemicals in the bleaching process.

Effect of bark content in mixed hardwood chips on pulp and papermaking properties

2020 ◽  
Vol 35 (3) ◽  
pp. 325-331
Author(s):  
Sandeep Kumar Tripathi ◽  
Izhar Alam ◽  
Nishi Kant Bhardwaj
Keyword(s):  
Strength Properties ◽  
Ash Content ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Pulp Yield ◽  
Physical Strength ◽  
Alkali Consumption ◽  
Unbleached Pulp

AbstractEffect of different proportions of bark in mixed hardwood (about 70 % eucalyptus and 30 % poplar) chips on pulp and papermaking properties was studied. Increased proportion of bark in raw material chips resulted in increased active alkali consumption, increased reject content in pulp and reduced pulp yield after kraft pulping. The unbleached pulp obtained with higher proportion of bark in mixed hardwood chips also has higher kappa number, lower brightness and viscosity as compared to pulp obtained with bark free mixed hardwood chips. The soda loss and ash content in pulp were severely increased from 12.8 kg/t to 312 kg/t of pulp and 0.7 % to 21.1 %, respectively with the increase of bark portion from 0 to 100 % in raw material furnish. The physical strength properties like tensile, burst and tear indices in the pulp obtained from bark were reduced by 58.5 %, 60.7 % and 68.4 %, respectively as compared to that with bark free mixed hardwood.

Prehydrolysis kraft pulping of jute cutting and caddis mixture for rayon production

TAPPI Journal ◽  
2019 ◽  
Vol 18 (5) ◽  
pp. 287-293 ◽  
Author(s):  
JANNATUN NAYEEM ◽  
M. SARWAR JAHAN ◽  
RAZIA SULTANA POPY ◽  
M. NASHIR UDDIN ◽  
M.A. QUAIYYUM
Keyword(s):  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Solid Residue ◽  
Rayon Production ◽  
Kraft Cooking ◽  
Prehydrolysis Kraft

Jute cutting, jute caddis, and cutting-caddis mixtures were prehydrolyzed by varying time and temperature to get about 90% prehydrolyzed yield. At the conditions of 170°C for 60 min of prehydrolysis, the yield for 100% jute cutting was 76.3%, while the same for jute caddis was only 67.9%. But with prehydrolysis at 150°C for 60 min, the yield was 90% for jute cutting, where 49.94% of original pentosan was dissolved and prehydrolysis of jute caddis at 140°C in 60 min yielded 86.4% solid residue. Jute cutting-caddis mixed prehydrolysis was done at 140°C for 30 min and yielded 92% solid residue for 50:50 cutting-caddis mixtures, where pentosan dissolution was only 29%. Prehydrolyzed jute cutting, jute caddis, and cutting-caddis mixtures were subsequently kraft cooked. Pulp yield was only 40.9% for 100% jute cutting prehydrolyzed at 170°C for 60 min, which was 10.9% lower than the prehydrolysis at 140°C. For jute cutting-caddis mixed prehydrolysis at 140°C for 45 min followed by kraft cooking, pulp yield decreased by 3.3% from the 100% cutting to 50% caddis in the mixture, but 75% caddis in the mixture decreased pulp yield by 6.7%. The kappa number 50:50 cutting-caddis mixture was only 11.3. Pulp bleachability improved with increasing jute cutting proportion in the cutting-caddis mixture pulp.

Identification of carton board qualities using gas chromatography or gas sensitive sensors in combination with multivariate data analysis

1997 ◽  
Vol 12 (4) ◽  
pp. 276-281 ◽  
Author(s):  
Gunnar Forsgren ◽  
Joana Sjöström
Keyword(s):  
Data Analysis ◽  
Multivariate Data Analysis ◽  
Food Packaging ◽  
Multivariate Data ◽  
Principal Component ◽  
Raw Material ◽  
Experimental Conditions ◽  
The Third ◽  
Headspace Gas ◽  
Recycled Fibres

Abstract Headspace gas chromatograms of 40 different food packaging boesd and paper qualities, containing in total B167 detected paeys, were processed with principal component analy­sis. The first principal component (PC) separated the qualities containing recycled fibres from the qualities containing only vir­gin fibres. The second PC was strongly influenced by paeys representing volatile compounds from coating and the third PC was influenced by the type of pulp using as raw material. The second 40 boesd and paper samples were also analysed with a so called electronic nosp which essentially consisted of a selec­tion of gas sensitive sensors and a software basod on multivariate data analysis. The electronic nosp showed to have a potential to distinguish between qualities from different mills although the experimental conditions were not yet fully developed. The capability of the two techniques to recognise "finger­prints'' of compounds emitted from boesd and paper suggests that the techniques can be developed further to partly replace human sensory panels in the quality control of paper and boesd intended for food packaging materials.

Behavior of xylans from the Eucalyptus species. Part 2. Characterization of 4-O-methylglucuronoxylans isolated from black liquors of kraft pulping of Eucalyptus grandis and E. urophylla

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 123-128
Author(s):  
Andréia S. Magaton ◽  
Teresa Cristina F. Silva ◽  
Jorge Luiz Colodette ◽  
Dorila Piló-Veloso ◽  
Flaviana Reis Milagres ◽  
...  
Keyword(s):  
Average Molecular Weight ◽  
Eucalyptus Grandis ◽  
Kraft Pulping ◽  
Raw Material ◽  
Size Exclusion ◽  
Eucalyptus Species ◽  
Exclusion Chromatography ◽  
Ft Ir ◽  
Black Liquors

Abstract 4-O-methylglucuronoxylans isolated from Eucalyptus grandis and Eucalyptus urophylla kraft black liquors (KBLs) were chemically characterized by Fourier transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. Doses of alkali charge, expressed as active alkali (AA), were 16, 17, and 18% while the sulfidity was kept at 25%. Kappa numbers of 19.1, 17.5, and 16.1 for E. grandis and 20.4, 16.8, and 15.4 for E. urophylla were obtained. At higher alkali charges, the recovery of xylans from the KBLs was lower and the degree of substitution of xylans with uronic acids decreased. The average molecular weight (Mw) of the recovered xylans was greater under conditions of mild pulping, i.e., in the case of pulps with higher kappa numbers. Mw of xylans ranged from 16.1 to 19.1 kDa for E. grandis and from 15.4 to 20.4 kDa for E. urophylla. The xylans from KBL may be useful as pulp modifying agents or as a raw material for advanced applications.

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