More and more industrial sectors (e.g. automotive, wind energy, boatbuilding) are demanding lightweight and high-performance composite materials, due to increased demand for reducing CO2 emissions and new applications in extreme environments, which represent a strong driving force to further develop the carbon fiber industry.
Today, almost 80% of the carbon fiber available on the market is using PolyAcryloNitrile (PAN) as the starting raw material because of its superior properties. However, carbon fibers produced from PAN are expensive which limit their application to premium industrial sectors looking for high-performance structural materials while accepting high material costs (e.g. aeronautics, space and defense). Moreover, it is acknowledged that precursor accounts for approximately 50% of the total manufacturing costs to produce carbon fibers and equipment accounts for approximately one third of the production cost.
Within this context, there is a crucial need to develop cost-effective precursors in order to produce carbon fibers at a more competitive price, which is the main barrier to address mass markets such as automotive industry, as well as emerging markets such as wind energy.
Two types of carbon fiber precursors will be investigated within CARBOPREC project: a high purity cellulose grade and a high purityorganosolvlignin grade, both doped by carbon nanotube (CNT).
Both cellulose and lignin-based precursors are actually widely available renewable sources. Moreover, they have already been investigated as carbon fiber precursors by world-class advanced research laboratories (e.g. Oak Ridge National Laboratory in US…) without meeting the expected mechanical performances.
The manufacturing process of white fiber (i.e. fiber before carbonization step) strongly depends on the macromolecular structure of renewable source precursor:
for high purity cellulose-based precursor: a preliminary phosphoric acid dissolution step is followed by a wet spinning process step,
for high purity lignin-based precursor: a preliminary compounding step is followed by a melt spinning process step.
The CARBOPREC project has a twofold purpose:
to carry out a comparative study onto both lignin and cellulose routes in order to develop a cost-effective manufacturing process at industrial scale for mass market applications,
to make suitable the carbonization process to both cellulose- and lignin-based precursor fibers in order to enhance the carbonization yield and to remove the oxidation step.
Furthermore, a plasma treatment will be developed in order to replace or to optimize the following steps of the manufacturing process: standard oxidation, carbonization and surface treatment.
The carbon fibers will be finally processed into fabrics and composite materials in order to provide a demonstrator for automotive and for wind blade energy.