Lignin-Derived Carbon Fibres: Opportunities and Challenges

Abstract

Carbon fibre (Graphite fibre) remains an important polymer in many industries due to its high tensile strength, lightweight and its inability to rust. It is nearly five times stronger than steel, three times lighter, twice as stiff and has better yield strength. Because of this, many weight-bearing metals like steel and aluminium can be replaced by carbon fibre. This paper explores the opportunities and challenges of using lignin as a precursor for carbon fibre production. This review revealed that lignin is considered waste in paper mills as it does not create desirable paper qualities, so most paper mills burn the excess lignin for fuel. Because lignin is considered waste to the paper and biofuel industries, these industries would be willing to sell the lignin to a carbon fibre plant as long as there is a greater profit rather than burning the lignin to save some money on energy costs. Furthermore, it was found that blending lignin from a different species can improve the fibre spinning, stabilisation rates, and properties of lignin-based carbon fibres. Again, being able to synthesise carbon fiber from lignin could be a possible solution to help make carbon fiber less expensive and simultaneously be produced from renewable resources. The review also revealed that the latest technologies, such as electrospinning, melt-spinning, dry-spinning and wet-spinning, are used in the production of carbon fibre. In summary, using lignin as a precursor for carbon fiber production offers opportunities to lower costs, utilise a renewable resource, and address recycling challenges. This promotes more sustainable and economical manufacturing of carbon fibre.