Improved yield of carbon fibres from cellulose and kraft lignin
Journal article, 2018

To meet the demand for carbon-fibre-reinforced composites in lightweight applications, cost-efficient processing and new raw materials are sought for. Cellulose and kraft lignin are each interesting renewables for this purpose due to their high availability. The molecular order of cellulose is an excellent property, as is the high carbon content of lignin. By co-processing cellulose and lignin, the advantages of these macromolecules are synergistic for producing carbon fibre (CF) of commercial grade in high yields. CFs were prepared from precursor fibres (PFs) made from 70:30 blends of softwood kraft lignin (SW-KL) and cellulose by dry-jet wet spinning with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) as a solvent. In focus was the impact of the molecular mass of lignin and the type of cellulose source on the CF yield and properties, while membrane-filtrated kraft lignin and cellulose from dissolving kraft pulp and fully bleached paper-grade SW-KP (kraft pulp) served as sources. Under the investigated conditions, the yield increased from around 22% for CF from neat cellulose to about 40% in the presence of lignin, irrespective of the type of SW-KL. The yield increment was also higher relative to the theoretical one for CF made from blends (69%) compared to those made from neat celluloses (48-51%). No difference in the mechanical properties of the produced CF was observed.


molecular mass


dissolving pulp

kraft pulp

carbon fibre (CF)

1-ethyl-3-methylimidazolium acetate (EMIMAc)

LignoBoost lignin

dry-jet wet-spun

softwood kraft lignin


Andreas Bengtsson

Royal Institute of Technology (KTH)

Jenny Bengtsson

Chalmers, Chemistry and Chemical Engineering, Chemical Technology

Carina Olsson


Maria Sedin

RISE Research Institutes of Sweden

Kerstin Jedvert


Hans Theliander

Chalmers, Chemistry and Chemical Engineering, Chemical Technology

Elisabeth Sjöholm

RISE Research Institutes of Sweden


0018-3830 (ISSN) 1437-434X (eISSN)

Vol. 72 12 1007-1016

Subject Categories

Polymer Chemistry

Paper, Pulp and Fiber Technology

Polymer Technologies



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