Energy reduction of refining by cellulases

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Michael Lecourt ◽  
Valérie Meyer ◽  
Jean-Claude Sigoillot ◽  
Michel Petit-Conil

Abstract The effect of three different commercial cellulase treatments applied on softwood bleached kraft pulp before the refining step was studied. Disc refining was applied under similar conditions as usual in paper mills. Two cellulase treatments allowed an energy saving of 20% to reach a given drainage index or breaking length. Water retention value (WRV), which characterizes the water absorption inside the fibre wall, was increased by the cellulase treatment. However, tear index losses were observed upon enzyme treatment. The third cellulase did not have an impact either on any parameters of the refining or on the pulp properties, except WRV. Viscosity measurements showed that the two first cellulases have strong endoglucanase activities but are lacking exoglucanase activities. Probably, endoglucanase activity weakens the fibre structure by generation of weak points or kinks. This hypothesis would explain the important cutting and fibrillation phenomena observed in the case of these two cellulases. It can be concluded that cellulase treatment could save 20% of electrical energy needed for refining, i.e., 50 kWh t-1, if a paper quality with a high tensile resistance but lowered tear strength is acceptable.

2012 ◽  
pp. 45-62
Author(s):  
Luz Moreno ◽  
Calixto Protacio

Given the increasing global demand for pulp, there is a need to look into the prospects of increasing fiber production and shortening the harvesting cycle of abaca without sacrificing the quality of fibers for pulp production. This study investigated the chemical and pulp properties of abaca cv. Inosa fibers harvested at different stages of stalk maturity to determine their suitability for pulp and paper production. Fibers obtained from 8-10-month-old (immature) abaca cv. Inosa possessed the desirable chemical properties for pulping, namely; low lignin and ash content, high alpha-cellulose, holocellulose and hemi- cellulose contents; which are comparable with those obtained from intermediate and mature stalks. The average pulp yield, Kappa number, viscosity, tear index and breaking length of pulps from immature stalks were already comparable with those of mature fibers and were even higher than the mature fibers of Linawaan and Laylay cultivars. Fibers of abaca cv. Inosa obtained from immature stalks were thus, found suitable for pulp and paper production.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (5) ◽  
pp. 19-25 ◽  
Author(s):  
PETER W. HART ◽  
DARRELL M. WAITE ◽  
LUC THIBAULT, ◽  
JOHN TOMASHEK ◽  
MARIE-EVE ROUSSEAU ◽  
...  

Eucalyptus wood chips were subjected to impregnation with various blends of novel fiber modify-ing enzymes before chemical pretreatment and two stages of refining using the preconditioning refiner chemical–alkaline peroxide mechanical pulping (PRC-APMP) process. Wood chip impregnation and pulp processing was con-ducted at a pilot plant in the United States. When compared under constant chemical application and at a constant 350 mL CSF, enzyme treatment reduced specific refining energy by at least 24%. The effect of one versus two stages of impregnation and of enzyme action upon several physical pulp properties was determined.


TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 631-639
Author(s):  
MOHAMMAD HADI ARYAIE MONFARED ◽  
HOSSEIN RESALATI ◽  
ALI GHASEMIAN ◽  
MARTIN A. HUBBE

This study investigated the addition of acrylic fiber to old corrugated container (OCC) pulp as a possible means of overcoming adverse effects of water-based pressure sensitive adhesives during manufacture of paper or paperboard. Such adhesives can constitute a main source of stickies, which hurt the efficiency of the papermaking process and make tacky spots in the product. The highest amount of acrylic fiber added to recycled pulps generally resulted in a 77% reduction in accepted pulp microstickies. The addition of acrylic fibers also increased pulp freeness, tear index, burst strength, and breaking length, though there was a reduction in screen yield. Hence, in addition to controlling the adverse effects of stickies, the addition of acrylic fibers resulted in the improvement of the mechanical properties of paper compared with a control sample.


2013 ◽  
Vol 779-780 ◽  
pp. 294-301
Author(s):  
Wan You Tang ◽  
Li Chen ◽  
Zheng Jian Zhang

Enzymatic refining of eucalypt bleached kraft pulp with the cellulase NOV476 was studied. The effects of this cellulase on the physical properties of pulp, fiber morphology and fiber appearance of the eucalypt bleached kraft pulp in different application conditions were discussed. The results show that, with the increase in the amount of enzyme, tensile strength index, burst index and TEA index of paper are increased and then decreased; elongation and tear index of paper have been declining, Zeeil tensile strength index has been an upward trend. Without beating the pulp sample, gradually increases as the amount of enzyme, the average fiber length and the average fiber width are gradually reduced, while mean kink index substantially constant. Number of vessels in fiber overall reduced tendency reaches a minimum in the amount of enzyme 0.5μ/g, the phenomenon is most obvious. In the same conditions of beating time, gradually increases as the amount of enzyme, the average fiber length is gradually reduced, an average fiber width is gradually increased, the mean kink index reaches a maximum in the amount of enzyme is 0.5μ/g. Number of vessels in fiber overall reduced trend.


2019 ◽  
Vol 9 (02) ◽  
pp. 65
Author(s):  
Hendro Risdianto ◽  
Sonny Kurnia Wirawan ◽  
Susi Sugesty

Refining merupakan proses untuk memodifikasi serat dengan tujuan meningkatkan ikatan serat dan mengembangkan kekuatan kertas. Penelitian yang telah dilakukan meliputi penentuan kondisi refining dengan PFI Mill dan penentuan kondisi perlakuan awal lakase yang selanjutnya akan diterapkan pada proses biorefining. Jumlah putaran 2500 dari PFI mill merupakan jumlah yang optimum untuk menghasilkan kekuatan pulp Acacia crassicarpa. Sedangkan hasil penelitian kondisi optimum lakase menunjukkan bahwa lakase memiliki laju reaksi yang paling tinggi (0,0018 mM/s) pada suhu 50°C. Pada proses refining, freeness awal pulp adalah sekitar 550 mL CSF, dan ketika dikenakan perlakuan lakase turun menjadi 515 (LMS1) dan 520 (LMS2). Refining pulp tanpa perlakuan enzim menghasilkan indeks tarik, retak dan sobek berturut-turut adalah 6,4.10-2 kNm/g, 5,18 kPa.m2/g, dan 5,96 mN.m2/g. Indeks sobek tidak mengalami perubahan signifikan pada semua perlakuan. Perlakuan LMS1 meningkatkan indeks tarik menjadi 6,83 kNm/g dan indeks sobek menjadi 7,53 mN.m2/g. Indeks tarik dan sobek pada LMS2 menurun dibandingkan LMS1, namun masih lebih tinggi dibandingkan tanpa perlakuan. Dengan demikian perlakuan lakase pada proses refining dapat meningkatkan indeks tarik dan indeks sobek lembaran.Laccase Application in Pulp Refining Process AbstractRefining is a process to modify fibers with the aim of increasing fiber bonds and developing paper strength. The research that has been done includes determining the refining conditions with PFI Mill and determining the conditions of pretreatment of laccase which will then be applied to the biorefining process. The PFI mill revolutions of 2500 is the optimum to produce the strength of the Acacia crassicarpa pulp. Whereas the results of the study showed that optimum laccase conditions showed that laccase had the highest reaction rate (0.0018 mM/s) at 50oC. In the refining process, the initial freeness of the pulp is around 550 mL CSF, and when subjected to laccase treatment it drops to 515 (LMS1) and 520 (LMS2). Refining the pulp without enzyme treatment produced tensile, bursting and tearing indexes of 6.4.10-2 kNm/g, 5.18 kPa.m2/g, and 5.96 mN.m2/g, respectively. The tear index did not change significantly in all treatments. The LMS1 treatment increased the tensile index to 6.83 kNm/g and the tear index to 7.53 mN.m2/g. The tensile and tear index in LMS2 decreased compared to LMS1, but it was still higher than without treatment. Thus, laccase treatment in the refining process can increase the tensile index and tear indexof the sheet.  


2010 ◽  
Vol 25 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Dmitri Gorski ◽  
Jan Hill ◽  
Per Engstrand ◽  
Lars Johansson

Abstract This review covers the effect of mechanical pre-treatment of wood chips on the energy consumption in refining and the quality of pulp. To understand the mechanisms of mechanical pre-treatment, a short description of relevant refining theory and reported effects of pre-treatment on wood morphology is given. Mechanical pre-treatment offers a chance to utilize the energy needed to defibrate chips in a more efficient way, minimizing the cyclic elastic deformations which are the main defibration mechanism in refining. Studies of fibre morphology indicate that compressive pretreatment mechanically introduces favorable weak points in the S1 and S2 fibre walls where defibration proceeds easier upon subsequent refining. Published results which cover the effect of the pretreatment on energy consumption and pulp properties are reviewed. Energy reduction of between 10% and 30% is reported in the literature. High ratio of volumetric compression is necessary. Pressurized conditions are required to ensure that the fibres are not damaged during the pre-treatment. Other effects of compressive pretreatment include a more uniform chip size and moisture content, better penetration of chemicals and removal of extractives from the chips. A list of equipment used for chip pre-compression is provided together with published results of pilot-scale and mill-scale operation.


Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 867-874 ◽  
Author(s):  
Ofélia Anjos ◽  
António J. A. Santos ◽  
Rogério Simões ◽  
Helena Pereira

Abstract The pulping properties of cypress species are not known and the present paper aims to filling this gap. Namely, Cupressus lusitanica Mill., C. sempervirens L. and C. arizonica Greene have been submitted to kraft pulping and the pulp properties are compared with those of Pinus pinaster Aiton. and P. sylvestris Watereri as references. Schopper Riegler degree, density, Bekk’s smoothness, tensile index, tear index, burst index, stretch, dry zero-span strength, wet zero-span strength, brightness, opacity and light scattering coefficient have been tested. The pulp yields and delignification degrees of cypress woods were lower than those of the pine references. Fibre length, width and coarseness were statistically different between pines and cypress species and C. sempervirens pulps have corresponding data close to those of pine species. Cypress pulps can be refined much faster than pine pulps. The papers sheets of cypress fibres have, in general, lower mechanical performance than those of pine fibres. Papers from C. arizonica and C. lusitanica are similar and C. sempervirens has intermediate properties being between the other cypress and pine species. However, cypress fibres are relatively short, flexible and collapsible and can be refined with low energy demand, and thus could be incorporated into papers resulting in products with better light scattering and smoothness.


2012 ◽  
Vol 581-582 ◽  
pp. 265-268
Author(s):  
Yong Sheng Ma ◽  
Lin Tong Wang ◽  
Xian Hui Sun ◽  
Jiang Qiang Zhang ◽  
Shun Ran Zhang

Application in paper pulp as dry strengthening agent of homemade water in water cationic polyacrylamide (CPAM) emulsion was studied. Good collaborative effect was achieved when Homemade CPAM was used in bleached wheat straw pulp with strengthening agent E and with cationic additives L as paper pulp strengthening agent. It was also showed that distinct strengthening effect was obtained when homemade CPAM emulsion was applied in mixture of wood pulp which was needle bleached kraft pulp (NBKP) and straw pulp, breaking length and tearing index of hand sheet made of mix pulp was respectively increased by 22.2% and17.0% when the dosage of CPAM was 0.8% of dry fiber. Through analysis of handsheet section scanning electron microscopy (SEM) photos, strengthening mechanism of CPAM emulsion to paper pulp was preliminary studied.


2021 ◽  
Vol 63 (3) ◽  
pp. 55-59
Author(s):  
Van Son Cao ◽  
◽  
Thi Quynh Hoa Le ◽  
Thi Thu Nguyet Do ◽  
Thanh Tu Do ◽  
...  

This paper presents the research results that established the main technological conditions in the production of greaseproof paper, used as the packaging of dry food as the proportion of pulp types, the degree of the beating of pulp, the use of chemicals and oil and greaseproof resistant agent to the properties of the paper on a laboratory scale. At the same time, experimental production and technology conditions were regulated on a 3 ton/day capacity line. The paper quality produced is equivalent to the imported paper products of the same type which is consumed in the market: basis weight: 42.5 g/m2; tensile breaking length: MD (Machine Direction): 7,520 m, CD (Cross Direction): 3,740 m; tear index: MD: 6.8 mN.m2/g, CD: 5.4 mN.m2/g; burst index: 5.6 kPa.m2/g; Cobb60: 17.2 g/m2; KIT rating: 8; ensuring food safety and hygiene.


2020 ◽  
Vol 71 (4) ◽  
pp. 365-370
Author(s):  
Emre Birinci ◽  
Ahmet Tutuş ◽  
Mustafa Çiçekler

In this study, Rhododendron luteum and Rhododendron ponticum were evaluated as raw material for pulp and paper production. 12 different sodium borohydride (NaBH4) added cooking trials were performed for each sample and kraft method was used for pulp production. Pulp properties, such as yield, kappa number and viscosity, and physical properties, such as breaking length and burst index, were determined for each trial. Besides, the effects of active alkali and NaBH4 on the pulp and paper properties were also examined. Optimum cooking conditions were obtained by using 18 % active alkali for NaBH4-free cooking experiments and 0.5 % NaBH4 and 18 % active alkali for NaBH4-added cooking experiments. In NaBH4-added pulping condition, the screened yield, kappa number and viscosity of R. luteum were found to be 43.4 %, 40.1 and 949 cm3/g1, respectively. The respective values for R. ponticum were 41.9 %, 44.5 and 885 cm3/g1. The screened yields of R. luteum and R. ponticum increased by about 2.8 % and 5.3 %, respectively, with 5 % addition of NaBH4 compared to NaBH4-free cooking experiments. Furthermore, with the addition of NaBH4, the kappa numbers decreased while the viscosity increased. The physical properties of the produced papers were also improved by using NaBH4 in cooking liquor. According to the obtained results, it was found that R. luteum and R. ponticum species can be evaluated for pulp and paper production.


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