Carbon fibres from Victorian lignite

Victorian brown coal shows promise as a naturally occurring precursor material for carbon fibre.

Carbon fibre exhibits outstanding specific strength and modulus, almost four times that of steel, making it one of the strongest materials on the planet today.

Carbon fibres are now being used commercially in structural, light-weight composites for a wide range of industries such as aerospace, automotive, bicycles, oil and gas, clean energy and sporting goods, where they are replacing traditional materials such as steel and aluminium. Carbon fibres are also starting to be used in the automotive industry, but greater market penetration is limited by cost. Currently, most carbon fibres are made from polyacrylonitrile (PAN) which is an expensive petroleum-based polymer contributing to more than 50% of the cost.

Victorian brown coal or lignite, with its inherently low nitrogen, low sulfur and low ash content, is arguably the cleanest coal in the world. It has lower levels of these ‘impurities’ than most forms of biomass. Since impurities often become concentrated in the product materials, this makes Victorian brown coal a near ideal naturally occurring precursor material for all sorts of carbon products. It is also very cheap due to its massive accumulation in large deposits that are already operational and readily mined by open cut methods.

In a collaborative project with Monash University, led by IFM’s Associate Professor Minoo Naebe, researchers are investigating the production of low-cost carbon fibres using precursors derived from Victorian lignite.

The project involves a team at the School of Chemistry at Monash University with expertise in chemical transformation and fractionation of Victorian lignite, and the IFM team at Carbon Nexus with expertise in production and characterisation of carbon fibres.

Carbon Nexus is a globally unique carbon fibre and composite materials research facility, which houses an industrial pilot and research scale carbon fibre processing line, a precursor fibre spinning line and composite manufacturing capabilities.

Carbon fibres containing up to 40% lignite have been produced using two of the extract materials using the wet-spinning technique and subsequent thermal stabilisation and carbonisation. Based on previous experience, the team is confident that, with further optimisation, carbon fibres with higher lignite content could be produced to meet the cost and performance requirements of the automotive industry.

Funding for this project is provided by Australian Carbon Innovation (ACI) and Australian National Low Emissions Coal Research and Development Ltd (ANLEC R&D).

Key Messages:

• Widespread commercial use of carbon fibres in the automotive industry requires a lower cost alternative to the current fibre precursor, polyacrylonitrile (PAN)
• Victorian lignite is an inexpensive source of suitable carbon
• This project involved a preliminary investigation of carbon fibre production using four different extracts derived from Victorian lignite
• The project successfully produced carbon fibres containing up to 40% Victorian lignite with PAN
• Further research is underway to increase the proportion of Victorian lignite and to improve the strength of the carbon fibres

For more information contact Associate Professor Minoo Naebe