Spinning sustainable carbon fibres for the energy transition

碳纤维被广泛应用，包括减轻重量，提高燃油效率和扩大车辆范围。虽然有助于使用的可持续性，但它们通常由石化产品制成。该项目开发了一种新的方法，从木质素（来自木材）中纺出可持续来源的碳纤维。来自Imperial的两项专利申请（GB申请2208061.8和2208067.5）支持引入极高比例（>90%）的工业木质素，并以高产率转化为更高性能的纤维。该项目将在单纤维规模上进行演示，开发纺丝工艺，以生产更均匀、更排列的纤维，并改善性能。关键是在纺丝过程中，通过碳化和随后的石墨化，原位监测纳米管/木质素混合物的复杂行为。木质素和纳米管之间的密切相互作用通过改变流变学而使纺丝成为可能，增加碳化过程中的产率，在较低温度下模板改善石墨化，并提供直接增强。这些效果将通过详细的表征研究来证明和理解，并通过用不同的化学物质专门接枝木质素来优化。Shaffer/Launois/Paineau最近表明，Ge掺杂的伊毛沸石纳米管为碳纳米管提供了一个极好的模型系统，提供了类似的现象学，但更好的机会，在纺丝过程中原位表征，利用其单分散性，散射强度和光学双折射（doi.org/10.1021/acsami.1c00971）。该项目提供了开发一种新型碳纤维的机会，可以与商业合作伙伴一起开发。美国能源部已经制定了一个低成本，可持续的石油衍生碳纤维替代品的目标，强度为1.7 GPa，刚度为170 GPa，成本<10英镑/千克。（j.carbpol.2020.116918）所提出的技术具有通过提供使用低成本可再生木质素原料（£0.3-0.5/kg）以及低成本和固有可再循环的离子液体（£1/kg）的稳健系统来实现这些目标的潜力。一旦这些关键性能指标得到满足，目前对生物衍生碳纤维的兴趣极大，包括潜在的商业合作伙伴。

Carbon fibres are widely applied, including to reduce weight, improve fuel efficiency, and extend vehicle range. Whilst contributing to sustainability in use, they are usually made from petrochemicals. This project develops a new approach to spinning sustainably-sourced carbon fibres from lignin (derived from wood). Two patent applications from Imperial (GB applications 2208061.8 and 2208067.5) underpin the incorporation of exceptionally high proportions (>90%) of industrial lignin, and conversion to higher performance fibres with high yield. Demonstrated at single fibre scale, the project will develop the spinning process to create more uniform, more aligned fibres, with improved properties.The key will be to monitor the complex behaviour of the nanotube/lignin hybrids, in situ, during spinning, through carbonisation, and subsequent graphitisation. Intimate interactions between lignin and nanotubes enable spinning by modifying rheology, increase yield during carbonisation, template improved graphiticity at lower temperatures, and provide direct reinforcement. These effects will be evidenced and understood by detailed characterisation studies and optimised by specially grafting lignins with different chemistries. Shaffer/Launois/Paineau have recently shown that Ge-doped imogolite nanotubes provide an excellent model system for carbon nanotubes, offering similar phenomenology but much better opportunities for in situ characterisation during spinning, exploiting their monodispersity, scattering strength, and optical birefringence (doi.org/10.1021/acsami.1c00971). The project offers the opportunity to develop a new class of carbon fibres that could be developed together with commercial partners. The DoE has set targets for a low-cost, sustainable alternative to petroleum derived carbon fibre at 1.7 GPa strength, 170 GPa stiffness and <£10/kg cost.(doi.org/10.1016/j.carbpol.2020.116918) The proposed technology has the potential to reach these targets by providing a robust system using low-cost renewable lignin feedstocks (£0.3-0.5/kg), as well as low cost and inherently recyclable ionic liquid (£1/kg). There is enormous current interest in bioderived carbon fibres, including from potential commercial partners, once these key performance metrics are met.