The Experts below are selected from a list of 2112 Experts worldwide ranked by ideXlab platform

Yonghao Ni - One of the best experts on this subject based on the ideXlab platform.

  • Ultrasonic treatment for enhancing the accessibility and reactivity of softwood rayon-grade kraft-based Dissolving Pulp
    Cellulose, 2019
    Co-Authors: Shuai Zhou, Lihui Chen, Liulian Huang, Yonghao Ni, Yali Li, Qingxian Miao
    Abstract:

    The cellulose reactivity is a critical parameter in the manufacturing process of viscose rayon with Dissolving Pulp. In this study, an ultrasonic treatment, which is considered as an environmentally friendly pretreatment technology, was applied to a softwood prehydrolysis kraft-based Dissolving Pulp for enhancement of accessibility/reactivity in terms of viscose rayon production through cavitation of ultrasound. Results show that the ultrasonic treatment can lead to the decrease of cellulose crystallinity, the increase of specific surface area and average pore diameter in fibers, and the increase of water retention value due to the release of energy induced by the collapse of the gas/vapor bubbles. As a consequence, the Fock reactivity and viscose filterability of Dissolving Pulp is enhanced significantly after ultrasonic treatment. Other parameters, such as intrinsic viscosity and fiber morphology were also determined.Graphic abstract

  • Applications of enzymatic technologies to the production of high-quality Dissolving Pulp: A review
    Bioresource Technology, 2019
    Co-Authors: Shuo Yang, Chao Duan, Jaroslav Stavik, Bo Yang, Darcy Alexandra Fuller, Xinqi Wang, Susmita Paul Chowdhury, Hongjie Zhang, Yonghao Ni
    Abstract:

    Abstract Recently, the worldwide production of Dissolving Pulp has grown rapidly. Enzymatic technologies play an important role in producing high-quality Dissolving Pulp, due to their green, mild conditions, high specificity and efficiency. In this review, the relevant publications regarding enzyme applications for Dissolving Pulp are summarized. Cellulase and xylanase are two major enzymes used for this purpose. Cellulase can improve the quality of Dissolving Pulp, such as improving the reactivity/accessibility, controlling the intrinsic viscosity and adjusting the molecular weight. Xylanase is mainly used to increase the purity of the Dissolving Pulp and improve the Pulp brightness. Furthermore, in order to increase the enzymatic treatment efficiency, the enzymatic technology can be combined with other techniques, including mechanical refining, fiber fractionations, alkali treatment and use of additives. The advantages, disadvantages and practical implications are analyzed. Also, the potential of other enzymes (such as laccase, mannanase) are discussed.

  • heteropoly acid catalytic treatment for reactivity enhancement and viscosity control of Dissolving Pulp
    Bioresource Technology, 2018
    Co-Authors: Xinqi Wang, Yonghao Ni, Chao Duan, Chengxin Zhao, Jingru Meng, Yongjian Xu
    Abstract:

    Abstract The reactivity enhancement and viscosity control are of practical importance during the manufacture of high-quality cellulose (also known as Dissolving Pulp). In the study, the concept of using phosphotungstic acid (HPW) for this purpose was demonstrated. The Fock reactivity of resultant Pulp increased from 49.1% to 74.1% after the HPW catalytic treatment at a dosage of 86.4 mg HPW/g odp. The improved results can be attributed to the increased fiber accessibility, thanks to the favorable fiber morphologic changes, such as increased pore volume/size, water retention value and specific surface area. HPW can be readily recycled/reused by evaporating method, where maintaining 87.1% catalytic activity after six recycle times. The HPW catalytic treatment concept may provide a green alternative for the manufacture of high-quality Dissolving Pulp.

  • fractionation and cellulase treatment for enhancing the properties of kraft based Dissolving Pulp
    Bioresource Technology, 2017
    Co-Authors: Yonghao Ni, Chao Duan, Xinqi Wang, Yongjian Xu, Yanling Zhang
    Abstract:

    Abstract 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.

  • recycling cellulase towards industrial application of enzyme treatment on hardwood kraft based Dissolving Pulp
    Bioresource Technology, 2016
    Co-Authors: Guihua Yang, Qiang Wang, Jiachuan Chen, Xingxiang Ji, Yonghao Ni
    Abstract:

    Abstract 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 1 mg/g led to the Pulp of viscosity 470 mL/g and Fock reactivity 80%, which is comparable with cellulase charge of 2 mg/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.

Qingxian Miao - One of the best experts on this subject based on the ideXlab platform.

  • Ultrasonic treatment for enhancing the accessibility and reactivity of softwood rayon-grade kraft-based Dissolving Pulp
    Cellulose, 2019
    Co-Authors: Shuai Zhou, Lihui Chen, Liulian Huang, Yonghao Ni, Yali Li, Qingxian Miao
    Abstract:

    The cellulose reactivity is a critical parameter in the manufacturing process of viscose rayon with Dissolving Pulp. In this study, an ultrasonic treatment, which is considered as an environmentally friendly pretreatment technology, was applied to a softwood prehydrolysis kraft-based Dissolving Pulp for enhancement of accessibility/reactivity in terms of viscose rayon production through cavitation of ultrasound. Results show that the ultrasonic treatment can lead to the decrease of cellulose crystallinity, the increase of specific surface area and average pore diameter in fibers, and the increase of water retention value due to the release of energy induced by the collapse of the gas/vapor bubbles. As a consequence, the Fock reactivity and viscose filterability of Dissolving Pulp is enhanced significantly after ultrasonic treatment. Other parameters, such as intrinsic viscosity and fiber morphology were also determined.Graphic abstract

  • Enhanced Reactivity of Kraft-based Viscose-grade Dissolving Pulp by Hollander Beating Treatment
    Bioresources, 2018
    Co-Authors: Shuai Zhou, Lihui Chen, Liulian Huang, Yali Li, Qingxian Miao
    Abstract:

    The reactivity of rayon-grade Dissolving Pulp is an important parameter in the subsequent production of viscose fiber. It can determine the processability and the quality of the viscose fiber. This study focused on improving the reactivity of kraft-based rayon-grade Dissolving Pulp through a mechanical treatment with mechanical refining, which could induce more fiber ends and channels or reactive sites via fiber cutting and fibrillation. Results showed that the Fock reactivity of a softwood kraft-based Dissolving Pulp increased from 54.4% to 68.4%, and the viscose filterability improved from 3743 s to 11 s when the beating degree of Dissolving Pulp was increased from 9 oSR to 16 oSR. Such a treatment also led to increases in the fines content, pore diameter, water retention value, and specific surface area while decreasing the fiber length. Meanwhile, it was beneficial that the intrinsic viscosity of Dissolving Pulp fiber was almost unaffected by the beating treatment.

  • Effect of the Utilization of Electron Beam Irradiation on the Reactivity of Bamboo Dissolving Pulp
    Bioresources, 2017
    Co-Authors: Qiuyan Chen, Qingxian Miao, Jianguo Li, Xiaojuan Ma, Liulian Huang
    Abstract:

    Electron beam irradiation (EBI) was used to improve the reactivity of bamboo Dissolving Pulp. An EBI treatment with a dose lower than 10 kGy showed that the Fock reactivity of the Dissolving Pulp noticeably increased from 69.5% to 98.3% with negligible cellulose losses. However, when the irradiation dose was higher than 10 kGy, the Fock reactivity increased with an observable α-cellulose loss, which could result in the lower strength of end-products. The gradual increase of Fock reactivity has a good agreement with the reduction of the degree of polymerization (DP) of cellulose. This suggests that lowering the DP of cellulose could enhance cellulose reactivity. Later analyses confirmed that an EBI treatment creates fiber pores that facilitate a cellulose xanthation reaction. The EBI treatment could randomly destroy cellulose crystalline and amorphous regions. The results indicated that the reactivity improvement was due not only to the DP, but also due to the changes in the fiber morphology and cellulose structure caused by the EBI processing.

  • Combined mechanical and enzymatic treatments for improving the Fock reactivity of hardwood kraft-based Dissolving Pulp
    Cellulose, 2014
    Co-Authors: Qingxian Miao, Linqiang Zheng, Chao Tian, Lihui Chen, Liulian Huang, Yonghao Ni
    Abstract:

    The cellulose reactivity is a key parameter in the viscose rayon production process. To increase the reactivity of hardwood kraft-based Dissolving Pulp, a combined mechanical refining and enzymatic treatment was applied based on the hypothesis that a mechanical pretreatment can enhance the subsequent enzymatic treatment efficiency. Compared with the control sample, increases in the fiber specific surface area and fines content of Dissolving Pulp by 66 and 10 %, respectively, were achieved because of the fiber fibrillation induced by PFI refining, which led to increased accessibility and thus enzymatic hydrolysis efficiency in the following cellulase treatment. As a result, the Fock reactivity by following the combined mechanical and enzymatic treatment was further enhanced, from 76 to 82 % compared with enzymatic treatment only. The effects of combined mechanical and enzymatic treatments on other properties of the Dissolving Pulp, for example, intrinsic viscosity and molecular weight, were also determined.

  • improving the reactivity of kraft based Dissolving Pulp for viscose rayon production by mechanical treatments
    Cellulose, 2014
    Co-Authors: Qingxian Miao, Linqiang Zheng, Chao Tian, Yonghao Ni
    Abstract:

    The capacity of Dissolving Pulp to react with carbon disulfide under the defined conditions, known as the “Fock reactivity,” is an important parameter in determining the processability, end-product quality, and environmental impact in downstream rayon production. This study was aimed at improving the reactivity of kraft-based Dissolving Pulp by mechanical treatments, such as grinding and PFI refining, which can induce additional accessible surfaces in the compact cellulose structure via fiber cutting and fibrillation, respectively. Results showed that the Fock reactivity of a kraft-based Dissolving Pulp was increased from 49.3 to 71.8 % by 6-min grinding treatment under the conditions studied. Such a treatment led to increases in the fines content and specific surface area while decreasing the fiber length, intrinsic viscosity, and the crystalline ratio of cellulose. PFI refining can also result in changes in the fiber morphology and cellulose structure; a 25,000 PFI revolution treatment led to an increase in the Fock reactivity from 49.3 to 58.3 % for the same Dissolving Pulp.

Qiang Wang - One of the best experts on this subject based on the ideXlab platform.

  • Tween 80 enhancing cellulase recyclability during activation of Dissolving Pulp
    Journal of Wood Chemistry and Technology, 2020
    Co-Authors: Huili He, Qiang Wang, Guihua Yang, Xingxiang Ji, Xin Fu, Jiachuan Chen
    Abstract:

    Enhancing cellulase recyclability is a promising approach to reducing the high enzyme cost for activation of Dissolving Pulp. For this purpose, Tween 80, an amphiphilic surfactant, was employed to ...

  • Correlation Between Fock Reactivity and Intrinsic Viscosity of Dissolving Pulp During Cellulase Treatment
    Journal of Wood Chemistry and Technology, 2019
    Co-Authors: Huili He, Qiang Wang, Guihua Yang, Xin Fu, Yingchao Wang, Jiachuan Chen
    Abstract:

    Cellulase treatment is an effective approach to upgrade Dissolving Pulp in a natural friendly way. In this study, a comprehensive experiment was conducted to understand the correlation of Fock reac...

  • Enzymatic activation of Dissolving Pulp with cationic polyacrylamide to enhance cellulase adsorption
    2017
    Co-Authors: Qiang Wang, Guihua Yang, Tianzhong Yuan, Wenhai Li, Rendang Yang
    Abstract:

    Cellulase treatment is a promising technology to improve the properties of Dissolving Pulp in an environmental friendly way. Increasing the cellulase treatment efficiency is of practical interest. In the present study, the concept of using cationic polyacrylamide (CPAM) to enhance the cellulase treatment efficiency was demonstrated. The hypothesis was that the CPAM would attribute to the increased cellulase adsorption onto cellulose fibers based on the patching/ bridging mechanism. Results showed that the viscosity decrease was improved with the addition of 250 ppm of CPAM under the same conditions as those of the control. Degraded cellulose content was increased based on the alkaline solubility analysis, while alpha- cellulose content kept constant. The CPAM- assisted cellulase treatment concept may provide a practical alternative method for upgrading Dissolving Pulp.

  • recycling cellulase towards industrial application of enzyme treatment on hardwood kraft based Dissolving Pulp
    Bioresource Technology, 2016
    Co-Authors: Guihua Yang, Qiang Wang, Jiachuan Chen, Xingxiang Ji, Yonghao Ni
    Abstract:

    Abstract 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 1 mg/g led to the Pulp of viscosity 470 mL/g and Fock reactivity 80%, which is comparable with cellulase charge of 2 mg/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.

  • high consistency cellulase treatment of hardwood prehydrolysis kraft based Dissolving Pulp
    Bioresource Technology, 2015
    Co-Authors: Qiang Wang, Guihua Yang, Jiachuan Chen, Yonghao Ni
    Abstract:

    Abstract 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 24 h. 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.

Jianguo Li - One of the best experts on this subject based on the ideXlab platform.

  • a new approach to improve Dissolving Pulp properties spraying cellulase on rewetted Pulp at a high fiber consistency
    Cellulose, 2018
    Co-Authors: Linqiang Zheng, Jianguo Li, Hailong Li, Shaokai Zhang, Kaixin Huang, Xinhua Ouyang
    Abstract:

    Cellulase treatment is a promising technology that will increase the reactivity of a prehydrolysis kraft (PHK) Dissolving Pulp. In this study, a cellulase solution was sprayed onto rewetted Pulp at a very high consistency (about 60%) to increase its Fock reactivity with high efficiency and low cost. This novel and facile approach is based on favorable cellulose adsorption onto Pulp fibers and high cellulose concentration at the reaction sites. Consequently, the enzymatic reactions towards cellulose fibers are more effective, thus a higher enzymatic performance in comparison with the conventional process. With the cellulase spraying technique under the conditions of 60% fiber consistency and 1.5 mg/g cellulase dosage at 12 h, the Fock reactivity of a PHK Dissolving Pulp increased from 51.22 to 82.64% with acceptable viscosity (469 mL/g). Herein, the proposed cellulase spraying technology is flexible and readily implementable in practice.

  • methods to increase the reactivity of Dissolving Pulp in the viscose rayon production process a review
    Cellulose, 2018
    Co-Authors: Zhibin He, Jianguo Li, Bo Yang, Hongjie Zhang, Hailong Li, Sarah Legere, Shaokai Zhang, Lili Zhang
    Abstract:

    Cellulose is a green and sustainable feedstock that can be used for manufacturing many bio-based products. Dissolving Pulps, the main source of high-purity cellulose, have been extensively used in the production of cellulose-based products. The reactivity of Dissolving Pulp is a critical property because a high reactivity can decrease the production cost and environmental impact of application processes, in particular for the viscose rayon production. This review discusses the factors which affect the reactivity of Dissolving Pulp, including raw materials, manufacturing processes, drying and oxidation. Various methods to increase the reactivity of Dissolving Pulp are discussed, and they include mechanical treatment, enzymatic treatment, caustic extraction, ionic liquid extraction, acid treatment, ozone treatment, thermal degradation, and their combinations. Their advantages and disadvantages are compared and analyzed. Finally, the practical implications of effective methods to improve the reactivity and the future of Dissolving Pulp are discussed.

  • Effect of the Utilization of Electron Beam Irradiation on the Reactivity of Bamboo Dissolving Pulp
    Bioresources, 2017
    Co-Authors: Qiuyan Chen, Qingxian Miao, Jianguo Li, Xiaojuan Ma, Liulian Huang
    Abstract:

    Electron beam irradiation (EBI) was used to improve the reactivity of bamboo Dissolving Pulp. An EBI treatment with a dose lower than 10 kGy showed that the Fock reactivity of the Dissolving Pulp noticeably increased from 69.5% to 98.3% with negligible cellulose losses. However, when the irradiation dose was higher than 10 kGy, the Fock reactivity increased with an observable α-cellulose loss, which could result in the lower strength of end-products. The gradual increase of Fock reactivity has a good agreement with the reduction of the degree of polymerization (DP) of cellulose. This suggests that lowering the DP of cellulose could enhance cellulose reactivity. Later analyses confirmed that an EBI treatment creates fiber pores that facilitate a cellulose xanthation reaction. The EBI treatment could randomly destroy cellulose crystalline and amorphous regions. The results indicated that the reactivity improvement was due not only to the DP, but also due to the changes in the fiber morphology and cellulose structure caused by the EBI processing.

  • cellulose Dissolving Pulp manufacturing processes and properties a mini review
    Bioresources, 2016
    Co-Authors: Chunxia Chen, Linqiang Zheng, Chao Duan, Jianguo Li, Jaroslav Stavik, Yonghao Ni
    Abstract:

    The increasing consumption of regenerated cellulose, in particular the viscose fiber, has led to a significant development of Dissolving Pulps in the last decade. In this review paper, the current status of Dissolving Pulp with respects to raw materials, manufacturing processes, and some key issues are discussed. Non-wood materials and the process concept of upgrading paper-grade Pulp into Dissolving Pulp are also included. Some recent developments related to the analytical methods of the purity and molecular weight distribution based on the ion chromatography and gel permeation chromatography are discussed. Finally, further processing improvements of purification, such as mechanical, chemical, and enzymatic treatment, and their combinations during the manufacturing process of Dissolving Pulp, are included.

  • combination of mechanical alkaline and enzymatic treatments to upgrade paper grade Pulp to Dissolving Pulp with high reactivity
    Bioresource Technology, 2016
    Co-Authors: Yonghao Ni, Chao Duan, Jianguo Li, Saurabh Kumar Verma
    Abstract:

    A modified process consisting of an initial mechanical refining (R) followed by a low-alkali (5.5% NaOH) cold caustic extraction (CCE) and finally an endoglucanase (EG) treatment (R-5.5%CCE-EG) was investigated for upgrading paper-grade Pulp to Dissolving Pulp. Results showed that compared to the conventional process (9%CCE-EG), the modified process can decrease the alkali concentration (from 9% to 5.5%) to achieve a similar hemicelluloses removal while simultaneously enhancing the Fock reactivity (from 62.2% to 81.0%). The improved results were due to the fact that the mechanical refining resulted in favorable fiber morphological changes, including increased pore volume/size, water retention value and specific surface area. Consequently, the hemicelluloses removal was enhanced even under the subsequent low-alkali CCE condition. A synergic effect of refining, low alkali concentration and enzymatic activation was responsible for the higher reactivity of resulting Dissolving Pulp.

Chao Duan - One of the best experts on this subject based on the ideXlab platform.

  • Applications of enzymatic technologies to the production of high-quality Dissolving Pulp: A review
    Bioresource Technology, 2019
    Co-Authors: Shuo Yang, Chao Duan, Jaroslav Stavik, Bo Yang, Darcy Alexandra Fuller, Xinqi Wang, Susmita Paul Chowdhury, Hongjie Zhang, Yonghao Ni
    Abstract:

    Abstract Recently, the worldwide production of Dissolving Pulp has grown rapidly. Enzymatic technologies play an important role in producing high-quality Dissolving Pulp, due to their green, mild conditions, high specificity and efficiency. In this review, the relevant publications regarding enzyme applications for Dissolving Pulp are summarized. Cellulase and xylanase are two major enzymes used for this purpose. Cellulase can improve the quality of Dissolving Pulp, such as improving the reactivity/accessibility, controlling the intrinsic viscosity and adjusting the molecular weight. Xylanase is mainly used to increase the purity of the Dissolving Pulp and improve the Pulp brightness. Furthermore, in order to increase the enzymatic treatment efficiency, the enzymatic technology can be combined with other techniques, including mechanical refining, fiber fractionations, alkali treatment and use of additives. The advantages, disadvantages and practical implications are analyzed. Also, the potential of other enzymes (such as laccase, mannanase) are discussed.

  • heteropoly acid catalytic treatment for reactivity enhancement and viscosity control of Dissolving Pulp
    Bioresource Technology, 2018
    Co-Authors: Xinqi Wang, Yonghao Ni, Chao Duan, Chengxin Zhao, Jingru Meng, Yongjian Xu
    Abstract:

    Abstract The reactivity enhancement and viscosity control are of practical importance during the manufacture of high-quality cellulose (also known as Dissolving Pulp). In the study, the concept of using phosphotungstic acid (HPW) for this purpose was demonstrated. The Fock reactivity of resultant Pulp increased from 49.1% to 74.1% after the HPW catalytic treatment at a dosage of 86.4 mg HPW/g odp. The improved results can be attributed to the increased fiber accessibility, thanks to the favorable fiber morphologic changes, such as increased pore volume/size, water retention value and specific surface area. HPW can be readily recycled/reused by evaporating method, where maintaining 87.1% catalytic activity after six recycle times. The HPW catalytic treatment concept may provide a green alternative for the manufacture of high-quality Dissolving Pulp.

  • fractionation and cellulase treatment for enhancing the properties of kraft based Dissolving Pulp
    Bioresource Technology, 2017
    Co-Authors: Yonghao Ni, Chao Duan, Xinqi Wang, Yongjian Xu, Yanling Zhang
    Abstract:

    Abstract 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.

  • cellulose Dissolving Pulp manufacturing processes and properties a mini review
    Bioresources, 2016
    Co-Authors: Chunxia Chen, Linqiang Zheng, Chao Duan, Jianguo Li, Jaroslav Stavik, Yonghao Ni
    Abstract:

    The increasing consumption of regenerated cellulose, in particular the viscose fiber, has led to a significant development of Dissolving Pulps in the last decade. In this review paper, the current status of Dissolving Pulp with respects to raw materials, manufacturing processes, and some key issues are discussed. Non-wood materials and the process concept of upgrading paper-grade Pulp into Dissolving Pulp are also included. Some recent developments related to the analytical methods of the purity and molecular weight distribution based on the ion chromatography and gel permeation chromatography are discussed. Finally, further processing improvements of purification, such as mechanical, chemical, and enzymatic treatment, and their combinations during the manufacturing process of Dissolving Pulp, are included.

  • combination of mechanical alkaline and enzymatic treatments to upgrade paper grade Pulp to Dissolving Pulp with high reactivity
    Bioresource Technology, 2016
    Co-Authors: Yonghao Ni, Chao Duan, Jianguo Li, Saurabh Kumar Verma
    Abstract:

    A modified process consisting of an initial mechanical refining (R) followed by a low-alkali (5.5% NaOH) cold caustic extraction (CCE) and finally an endoglucanase (EG) treatment (R-5.5%CCE-EG) was investigated for upgrading paper-grade Pulp to Dissolving Pulp. Results showed that compared to the conventional process (9%CCE-EG), the modified process can decrease the alkali concentration (from 9% to 5.5%) to achieve a similar hemicelluloses removal while simultaneously enhancing the Fock reactivity (from 62.2% to 81.0%). The improved results were due to the fact that the mechanical refining resulted in favorable fiber morphological changes, including increased pore volume/size, water retention value and specific surface area. Consequently, the hemicelluloses removal was enhanced even under the subsequent low-alkali CCE condition. A synergic effect of refining, low alkali concentration and enzymatic activation was responsible for the higher reactivity of resulting Dissolving Pulp.