title: Combination of mechanical, alkaline and enzymatic treatments to upgrade paper-grade pulp to dissolving pulp with high reactivity.
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.
authors.affiliation: Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China; Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
authors.forename: Chao
authors.initials: C
authors.lastname: Duan
authors.affiliation: Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada; Department of Chemistry, Indian Institute of Technology, Guwahati, 781039, India.
authors.forename: Saurabh Kumar
authors.initials: SK
authors.lastname: Verma
authors.affiliation: Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China; Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Li
authors.affiliation: Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada; College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Ma
authors.affiliation: Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China; Limerick Pulp and Paper Centre, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: yonghao@unb.ca.
authors.forename: Yonghao
authors.initials: Y
authors.lastname: Ni
mesh_terms: D000468:Alkalies / Q000737:chemistry; D002241:Carbohydrates / Q000737:chemistry; D002480:Cellulase / Q000737:chemistry*; D003080:Cold Temperature; D010450:Endopeptidases / Q000737:chemistry; D004798:Enzymes / Q000737:chemistry*; D004950:Esterases / Q000737:chemistry; D007220:Industrial Waste; D008970:Molecular Weight; D010209:Paper; D011134:Polysaccharides / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods; D012972:Sodium Hydroxide / Q000737:chemistry; D013314:Stress, Mechanical; D014783:Viscosity; D014867:Water / Q000737:chemistry; D014934:Wood
chemical_list: D000468:Alkalies; D002241:Carbohydrates; D004798:Enzymes; D007220:Industrial Waste; D011134:Polysaccharides; D014867:Water; D012972:Sodium Hydroxide; C007916:hemicellulose; D004950:Esterases; D002480:Cellulase; D010450:Endopeptidases
keywords: Cold caustic extraction; Dissolving pulp; Mechanical refining; Paper-grade pulp; Reactivity