【Frontiers in HaiChuan Chemical Technology】Successful development of a 3-second solid-flame upgrading and recycling technology for carbon fiber

Thread Content

Recently, the teams led by Professors Fei Weidong and Wang Lidong from the School of Materials Science and Engineering at Harbin Institute of Technology, together with the team led by Associate Researcher Sheng Jie from the Institute of Space Environment and Material Science, made breakthrough progress in the field of carbon fiber recycling. They successfully developed a 3-second solid-flame upcycling technology for recycling carbon fibers. The relevant findings were published in the internationally renowned journal Nature Communications under the title “Upcycling carbon fibre wastes in solid-flames”. Addressing the challenges associated with the recycling of thermosetting carbon fiber composites (CFRP), this technology utilizes the principle of self-propagating high-temperature synthesis (SHS). It employs magnesium powder and calcium carbonate powder as reactants, enabling efficient treatment of waste carbon fiber composites in just 3 seconds. During the reaction process, a high temperature of 800–1000°C is generated instantaneously. Through an electron transfer effect, magnesium atoms weaken the bond energy between aromatic groups and oxygen atoms in the epoxy resin, thereby facilitating the breakage of C-O bonds and the formation of C-C bonds. This leads to rapid decomposition of the resin. At the same time, graphene is grafted in situ onto the defect sites of carbon fibers, resulting in the simultaneous production of two high-value products: graphene-grafted carbon fibers (GCFs) and high-purity graphene powder. Compared to traditional pyrolysis and chemical recycling methods, this technology offers significant advantages: the processing speed is increased by several hundred times; the energy consumption required for ignition is merely 0.009 kJ/g; overall energy consumption is reduced by 60%, and CO₂ emissions are cut by 75% ； The strength retention rate of recycled carbon fiber exceeds 95%, with further improvements in interfacial strength and mechanical properties; its strengthening effect is superior to that of virgin carbon fiber ； It can handle various types of waste materials such as carbon fiber scraps, prepregs, and used components in one go, meeting the needs of large-scale green recycling. In terms of applications, graphene-grafted carbon fiber can be used in fields such as aerospace, the lightweighting of new energy vehicles, and the reinforcement of high-performance structures in wind turbine blades ； The graphene powder produced synchronously is widely used in high-end applications such as electromagnetic shielding, battery electrodes, and thermal conductive materials, thereby enhancing the value of the industrial chain. Industry experts say that this technology provides a \"Chinese solution\" for the high-value recycling of carbon fiber waste worldwide, and it holds significant engineering value in facilitating the green transformation and sustainable development of the composite materials industry. Currently, the team has collaborated with enterprises to build a 100-ton/year pilot production line, accelerating the industrial application of the technology.