Cellulose was first precursor fibre material used for
production of carbon fibres. It has been in many
application replaced with polyacrylonitrile (PAN) and
isotropic pitch, especially in high modulus applications.
However, cellulose and more precisely viscose (rayon),
has still remained some markets due to beneficial
properties including good thermal stability of resulted
fibres, and low price of raw material and precursor fibre
production compared to PAN. Additional attractive feature
is its renewability and bio-based origin.
We have studied the use of regenerated cellulosic fibres
for production of carbon fibres. We used wet-spun
non-viscose fibres from enzymatically treated dissolved
cellulose, so called Biocelsol fibres, and nitrogen
containing cellulose carbamate. We studied the use of
various chemical agents, (NH4)2HPO4, H2SO4, and NH4Cl, in
order to increase low carbon yield and produced carbon
fibres and activated carbon fibres and nonwovens. In this
presentation we review work carried out and results
obtained within this study.
In preliminary trials we studied the effect of different
impregnation agents on carbon yield. Obtained carbon
yields in these un-optimized cases were 14 -21 %, which
was significantly higher than of non-treated reference
(10%). Best carbon yield was obtained with (NH4)2HPO4,
which was selected for sample preparation. We produced
both carbon fibres with tensioning during carbonization
as well as CO2 activated carbon fibres.
Strength of the obtained carbon fibre samples was not as
good as needed for load-bearing composite applications,
since we were not able to apply sufficient tensioning.
With better optimized carbonization process we, however,
were able to obtain carbon yield of above 30 % and fibres
showed good conductivity (above 4000 S/m). Possible use
of such material could be e.g. conductive filler in
Activated carbon fibres and nonwovens had surface areas
above 1000 m2/g and single samples even above 2000 m2/g.
Fibre and nonwovens were coherent and they could be used
e.g. for water purification and removal of odours from
This work was carried out in 'Bio-Based Tailored
Precursors for Advanced Carbons and Applications'
(BioPreCarb) project funded by Tekes - the Finnish
Funding Agency for Technology and Innovation, VTT
Technical Research Centre of Finland and Tampere
University of Technology. Project was aiming to review
possibilities to create bio-based carbon business in
|Conference||6th Nordic Wood Biorefinery Conference, NWBC 2015|
|Abbreviated title||NWBC 2015|
|Period||20/10/15 → 22/10/15|