Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin
Extracting lignin from black liquor is an attractive option in modern pulp mills as a unit process for a combined biorefinery. The lignin obtained can be utilized as solid fuel or other high-value added products. The precipitation equilibrium of kraft lignin from softwood black liquor was studied in...
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| Format: | Article |
| Language: | English |
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North Carolina State University
2015-01-01
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| Series: | BioResources |
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| Online Access: | http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_10_1_1696_Zhu_Precipitation_Lignin_Softwood_Black_Liquor |
| _version_ | 1828871296906166272 |
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| author | Weizhen Zhu Hans Theliander |
| author_facet | Weizhen Zhu Hans Theliander |
| author_sort | Weizhen Zhu |
| collection | DOAJ |
| description | Extracting lignin from black liquor is an attractive option in modern pulp mills as a unit process for a combined biorefinery. The lignin obtained can be utilized as solid fuel or other high-value added products. The precipitation equilibrium of kraft lignin from softwood black liquor was studied in this work. It was found that with decreasing pH and temperature, or increasing ion strength, the solid yield increases. Moreover, precipitated softwood kraft lignin has a higher molecular weight and contains lower amounts of carbohydrates and phenolic groups than lignin precipitated from mixed hardwood/softwood black liquor. The content of methoxyl groups in softwood kraft lignin was found to decrease with increasing precipitation yield. An empirical model for estimating the precipitation yield of lignin was proposed and evaluated. |
| first_indexed | 2024-12-13T06:29:03Z |
| format | Article |
| id | doaj.art-297909b3062340738aeea711fa71a424 |
| institution | Directory Open Access Journal |
| issn | 1930-2126 1930-2126 |
| language | English |
| last_indexed | 2024-12-13T06:29:03Z |
| publishDate | 2015-01-01 |
| publisher | North Carolina State University |
| record_format | Article |
| series | BioResources |
| spelling | doaj.art-297909b3062340738aeea711fa71a4242022-12-21T23:56:39ZengNorth Carolina State UniversityBioResources1930-21261930-21262015-01-011011696171410.15376/biores.10.1.1696-1715Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of LigninWeizhen Zhu0Hans Theliander1Chalmers University of Technology; SwedenChalmers University of Technology Wallenberg Wood Science Center; SwedenExtracting lignin from black liquor is an attractive option in modern pulp mills as a unit process for a combined biorefinery. The lignin obtained can be utilized as solid fuel or other high-value added products. The precipitation equilibrium of kraft lignin from softwood black liquor was studied in this work. It was found that with decreasing pH and temperature, or increasing ion strength, the solid yield increases. Moreover, precipitated softwood kraft lignin has a higher molecular weight and contains lower amounts of carbohydrates and phenolic groups than lignin precipitated from mixed hardwood/softwood black liquor. The content of methoxyl groups in softwood kraft lignin was found to decrease with increasing precipitation yield. An empirical model for estimating the precipitation yield of lignin was proposed and evaluated.http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_10_1_1696_Zhu_Precipitation_Lignin_Softwood_Black_LiquorMolecular weight of woodSoftwood black liquorCarbohydrate analysisLignoboost process1H and 13C NMR spectra of kraft ligninLignin precipitation |
| spellingShingle | Weizhen Zhu Hans Theliander Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin BioResources Molecular weight of wood Softwood black liquor Carbohydrate analysis Lignoboost process 1H and 13C NMR spectra of kraft lignin Lignin precipitation |
| title | Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin |
| title_full | Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin |
| title_fullStr | Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin |
| title_full_unstemmed | Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin |
| title_short | Precipitation of Lignin from Softwood Black Liquor: An Investigation of the Equilibrium and Molecular Properties of Lignin |
| title_sort | precipitation of lignin from softwood black liquor an investigation of the equilibrium and molecular properties of lignin |
| topic | Molecular weight of wood Softwood black liquor Carbohydrate analysis Lignoboost process 1H and 13C NMR spectra of kraft lignin Lignin precipitation |
| url | http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_10_1_1696_Zhu_Precipitation_Lignin_Softwood_Black_Liquor |
| work_keys_str_mv | AT weizhenzhu precipitationofligninfromsoftwoodblackliquoraninvestigationoftheequilibriumandmolecularpropertiesoflignin AT hanstheliander precipitationofligninfromsoftwoodblackliquoraninvestigationoftheequilibriumandmolecularpropertiesoflignin |