Research articleNovel multidimensional carbons from structural transformations of waste lignin: A low temperature pyrolysis investigation

- Low temperature pyrolysis of waste lignin in the temperature range 200-800 °C
- Characterization of chars using XRD, SEM, BET, FTIR, Raman, NMR techniques
- Carbon structures were seen to evolve as a function of pyrolysis temperature.
- The presence of nano-fibers, micro-ribbons and complex 3D networks was observed.
- Low cost environmentally sustainable avenue for the utilization of waste lignin

Low temperature pyrolysis investigations were carried out on waste lignin, a coproduct of bioethanol production from sugarcane bagasse, in the temperature range 200-800 °C for 15 to 60 min under argon atmosphere. In-depth characterization of resulting chars was carried out using a range of analytical techniques including XRD, HRSEM, EDS, NMR, FTIR, Raman and BET analysis. In addition to good agreement with the published literature, we report the formation of range of multidimensional carbons from waste lignin in the form of nanofibers, micro-ribbons, complex 3D structures and their blends. XRD data showed the evolution of crystalline as well as amorphous structures as a function of temperature. Reaction pathways for structure evolution and associated phase transformations were also identified. The preparation of these novel carbon structural forms from an abundant, waste bioresource could help realize the untapped potential of waste lignin, the exploration of their properties and future applications.