Tall oil pitch as a graphite feedstock: Catalyst-free thermal conversion of a biomass-derived by-product into bulk graphite.

Tall oil pitch (TOP), a high-boiling by-product obtained from crude tall oil refining in the kraft pulping process, was converted into bulk graphite through catalyst-free thermal treatment. Raman spectroscopy and X-ray diffraction showed the development of graphitic structural ordering, demonstrating that TOP can serve as a precursor for bulk graphite without catalysts or prior purification. Polarized optical microscopy of a heat-treated distilled residue derived from the TOP-derived pitch revealed well-developed flow-textured mesophase, providing evidence that TOP undergoes transformation toward a graphitizable intermediate during thermal treatment. These results indicate that multicomponent resin-derived residues can serve as precursors for graphite formation without catalytic assistance. This work expands the range of candidate feedstocks for graphite production to include industrial by-products from biomass refining.