Microwave-Assisted Production of Carbon Fibres from Crosslinked Lignin

Today, most carbon fibres are produced from the fossil-based raw material polyacrylonitrile (PAN), and the manufacturing process is energy intensive. The LignoWave-CF project investigates an alternative route in which lignin, a by-product of the forest industry, is used as a feedstock while microwave heating replaces conventional furnace-based heating.

Objectives

The project aims to verify a method for producing high-performance carbon fibres from chemically crosslinked lignin fibres using microwave technology. The goal is to develop lignin-based precursor fibres that retain their shape at high temperatures, can be stretched to create a favourable fibre structure, and subsequently converted into carbon fibres with minimal defects. The project will also assess whether the microwave-based process can reduce energy consumption and shorten production times compared with conventional furnace heating.

Why the project is important

The project has the potential to create a new application for lignin, a by-product generated in large volumes by the pulp, paper and biorefinery industries. If lignin can replace fossil-based feedstocks in carbon fibre production, it could reduce dependence on petroleum-derived materials while increasing the value of forest-industry side streams. In addition, the microwave-based process may contribute to lower energy use and shorter processing times. In the longer term, this could strengthen the supply of carbon fibres and support more resource-efficient manufacturing in Sweden and Europe.

Expected results

The project will verify the concept of chemically crosslinked lignin-based precursor fibres combined with microwave-assisted carbon fibre production at laboratory scale. The results will provide knowledge of how material composition and process conditions influence fibre structure, porosity and mechanical performance. The project will also deliver simulation-based comparisons of carbon fibre composites and provide a foundation for further development and scale-up.