Baker et. used a kraft pulping process to extract the HWKL and then organically purify it by treating it with organic solvents. Treatment with organic solvent removes impurities, improves spinnability, reduces melting point, reduces glass transition temperature (Tg), increases viscosity-time stability, and increases the thermal stability of HWKL. However, the obtained organically purified hardwood kraft lignin (HWKL-OP) has a slightly lower carbon content than the original HWKL. The possible reason for the low carbon content in HWKL-OP may be the reduction in molecular mass during the purification step. HWKL-OP was pelletized prior to melt spinning, after which the lignin pellets were melt spun into the fibers. The obtained precursor fibers were thermostabilized at 250°C at 0.01°C/min in the presence of air. However, the rate of thermostabilization should be ≤0.05°C/min because higher thermostabilization rates result in fusion between fibers. Finally, the carbonization was done at 1000°C at 2°C/min. Notably, carbonization is possible only when the thermostabilization rate is 0.05°C/min. The resulting carbon fibers' mechanical properties were satisfactory.