| 1. |
- Abdelaziz, Omar Y., et al.
(författare)
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Recent strides toward transforming lignin into plastics and aqueous electrolytes for flow batteries
- 2024
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Ingår i: iScience. - : Elsevier Inc.. - 2589-0042. ; 27:4
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Forskningsöversikt (refereegranskat)abstract
- Lignin is an abundant polyaromatic polymer with a wide range of potential future uses. However, the conversion of lignin into valuable products comes at a cost, and medium- to high-value applications are thus appropriate. Two examples of these are polymers (e.g., as fibers, plasticizers, or additives) and flow batteries (e.g., as redox species). Both of these areas would benefit from lignin-derived molecules with potentially low molecular weight and high (electro)chemical functionality. A promising route to obtain these molecules is oxidative lignin depolymerization, as it enables the formation of targeted compounds with multiple functionalities. An application with high potential in the production of plastics is the synthesis of new sustainable polymers. Employing organic molecules, such as quinones and heterocycles, would constitute an important step toward the sustainability of aqueous flow batteries, and lignin and its derivatives are emerging as redox species, mainly due to their low cost and renewability.
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| 2. |
- Battestini Vives, Mariona, et al.
(författare)
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Low-Molecular-Weight Lignin Recovery with Nanofiltration in the Kraft Pulping Process
- 2022
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Ingår i: Membranes. - : MDPI AG. - 2077-0375. ; 12:3, s. 310-310
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Tidskriftsartikel (refereegranskat)abstract
- Kraft lignin is an underutilized resource from the pulp and paper industry with the potential of being a key raw material for renewable fuels and chemicals. The separation of high-molecular-weight lignin from black liquor by ultrafiltration has been widely investigated, while the permeate containing low-molecular-weight lignin has received little attention. Nanofiltration can concentrate the low-molecular-weight lignin. This work, therefore, evaluates nanofiltration for the separation and concentration of low-molecular-weight lignin from the ultrafiltration permeate. For this study, eight flat polymeric sheet membranes and one polymeric hollow fiber membrane, with molecular weight cut-offs ranging from 100 to 2000 Da, were tested. A parametric study was conducted at 50 °C, 2.5–35 bar, and crossflow velocity of 0.3–0.5 m/s. At a transmembrane pressure of 35 bar, the best performing membranes were NF090801, with 90% lignin retention and 37 L/m2·h, and SelRO MPF-36, with 84% lignin retention and 72 L/m2·h. The other membranes showed either very high lignin retention with a very low flux or a high flux with retention lower than 80%. Concentration studies were performed with the two selected membranes at conditions (A) 50 °C and 35 bar and (B) 70 °C and 15 bar. The NF090801 membrane had the highest flux and lignin retention during the concentration studies. Overall, it was shown that the nanofiltration process is able to produce a concentrated lignin fraction, which can be either used to produce valuable chemicals or used to make lignin oil.
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| 3. |
- Battestini Vives, Mariona, et al.
(författare)
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Recovery and Characterization of Low-Molecular-Weight Lignin from Ultrafiltered Kraft Black Liquor
- 2022
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Ingår i: <em>10<sup>th</sup> Nordic Wood Biorefinery Conference</em>. - Helsinki. - 9789513887728 ; , s. 218-219
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Kraft lignin is an aromatic polymer found in black liquor, a side stream of the kraft pulping industry.Usually, lignin is burned in the recovery boiler of the pulp mill as a fuel for energy generation. However,lignin has great potential as a raw material for the production of fossil-free fuels, chemicals, andmaterials. Membrane filtration has been studied in the last decades as a key separation method torecover lignin from black liquor. Further studies to concentrate lignin using membrane filtration arerequired, as well as characterization of the resulting lignin fractions for the development of moleculartailored lignin-based applications.In the present work, nanofiltration (NF) was used to concentrate and recover the low-molecularweightlignin obtained from the permeate of ultrafiltration of kraft black liquor. The concentration wasperformed using a NF090801 polymeric NF membrane (SolSep) with a molecular weight cut-off of 350Da. A transmembrane pressure of 25 bar and 50 °C during the filtration increased the lignin contentfrom 27 to 52 g/l, whereas a transmembrane pressure of 15 bar and 70 °C gave an increase from 18 to45 g/l in lignin content. The lignin fraction recovered in the retentate of the NF step was analyzed bysize-exclusion chromatography to ascertain the molecular weight of the lignin. Moreover, Fouriertransform infrared spectroscopy and thermogravimetric analysis were carried out to evaluate thethermal properties and functionalities of the obtained fractions.
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| 4. |
- Lipnizki, Frank, et al.
(författare)
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Anwendungspotenzial von Membranprozessen im Konzept der Lignocellulose-Bioraffinerien
- 2021
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Ingår i: Chemie Ingenieur Technik. - : Wiley. - 1522-2640 .- 0009-286X. ; 93
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Tidskriftsartikel (refereegranskat)abstract
- The pulp and paper industry is one of the most important industrial sectors worldwide and has great potential to be a cornerstone for the future bioeconomy, especially for lignocellulosic biorefineries. The potential of membrane processes in this transformation is shown in three examples from the fields of Kraft / Sulphate, Sulphite and thermomechanical pulping. In addition, the challenges of membrane fouling and cleaning with regard to the pulp industry are discussed and an outlook on future developments of membranes in biorefineries is given.
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| 5. |
- Lipnizki, Frank, et al.
(författare)
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Potential of membrane processes in the concept of lignocellulose biorefineries
- 2022
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Ingår i: - : AEE INTEC. ; , s. 67-68
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Konferensbidrag (refereegranskat)abstract
- The pulp and paper industry is one of the key industrial sectors worldwide and is a cornerstone for conversion 10 toward a future bio-economy in particular as lignocellulosic bio-refineries. In this presentation, the potential of pressure-driven membrane processes – microfiltration, ultrafiltration and nanofiltration – in this conversion will be highlighted in three application studies related to thermomechanical, kraft/sulphate, and sulphite pulping. Moreover, the challenges of membrane fouling and cleaning in the pulping industry will be discussed and an outlook on future developments of membranes in biorefineries will be provided.
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