| 1. |
- Hubbe, Martin A., et al.
(författare)
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Lignin Recovery from Spent Alkaline Pulping Liquors Using Acidification, Membrane Separation, and Related Processing Steps : A Review
- 2019
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Ingår i: BioResources. - : NORTH CAROLINA STATE UNIV. - 1930-2126. ; 14:1, s. 2300-2351
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Tidskriftsartikel (refereegranskat)abstract
- The separation of lignin from the black liquor generated during alkaline pulping is reviewed in this article with an emphasis on chemistry. Based on published accounts, the precipitation of lignin from spent pulping liquor by addition of acids can be understood based on dissociation equilibria of weak acid groups, which affects the solubility behavior of lignin-related chemical species. Solubility issues also govern lignin separation technologies based on ultrafiltration membranes; reduction in membrane permeability is often affected by conditions leading to decreased solubility of lignin decomposition products and the presence of colloidal matter. Advances in understanding of such phenomena have potential to enable higher-value uses of black liquor components, including biorefinery options, alternative ways to recover the chemicals used to cook pulp, and debottlenecking of kraft recovery processes.
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| 2. |
- Kihlman, Jonas, 1982-
(författare)
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Multi Product Pulping
- 2016
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Ingår i: Multi Product Pulping.
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Konferensbidrag (refereegranskat)
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| 3. |
- Kihlman, Jonas, 1982-
(författare)
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On the resource efficiency of kraft lignin extraction
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lignin is regarded as a promising raw material for the production of biobased products, such as chemicals, materials and fuels, and will most probably be a key component in future lignocellulosic biorefineries.This thesis examines the lignin extraction process in a kraft pulp mill, the technologies that are available for this purpose, and the impact made on the mill. Several different kraft lignin extraction processes and technologies are currently available and are basically linear: chemicals are brought from outside the mill and introduced into the process and the mill balance. Depending on their origin, the addition of these chemicals will affect the mill to a lesser or greater degree, both economically and environmentally. A conceivable way of reducing the impact made on the mill´s balance would be the in-house production of the chemicals used, sulphuric acid and CO2, which takes a more sustainable circular approach.The results obtained show that utilisation of existing process streams in the mill as a source of chemicals could be a way of not only reducing these impacts but also making lignin extraction more sustainable. Internal production of sulphuric acid is possible and could generate a substantial amount for use as replacement of the fresh sulphuric acid needed for the lignin extraction process; CO2 is available in large quantities in the mill and could be captured and used for lignin extraction.
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| 4. |
- Kihlman, Jonas, 1982-, et al.
(författare)
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The feasibility of utilizing existing process streams in kraft pulp mills as a source of chemicals for lignin extraction
- 2021
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Ingår i: BioResources. - : North Carolina State University. - 1930-2126. ; 16:1, s. 1009-1028
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Tidskriftsartikel (refereegranskat)abstract
- Lignin is a sustainable raw material with a high potential for use in the production of renewable products. While the market for lignin is slowly growing, lignin recovery via acid precipitation during the kraft pulping process requires the addition of chemicals that will impact the chemical balance of the pulp mill. This negatively affects both the environmental and business operations. Utilizing existing process streams as a source of chemicals will allow the mill to close the chemical loop and reduce emissions, which will have positive environmental impacts. This study investigated the internal production of sulphuric acid (H2SO4) and carbon dioxide (CO2) for use in lignin separation (also called extraction) at a Swedish kraft pulp mill. The process simulation tool CHEMCAD was used to model and analyze the wet gas H2SO4 (WSA) process to produce H2SO4. The chemical absorption process using monoethanolamine (MEA) to capturing CO2 was also analyzed. The utilization of the sulphur-containing gases to produce H2SO4 can generate an amount that corresponds to a significant lignin extraction rate. The CO2 available in the flue gases from a mill well exceeds the amount required for lignin extraction.
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| 5. |
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