Solution spinning is preferred for producing lignin-based carbon fibers with enhanced mechanical properties. There are two types of solution spinning: wet spinning and dry spinning. The heated polymer solution is extruded through a spinneret and into a tower with a continuous supply of heated inert gas after dry spinning. The temperature of the heated inert gas is higher than the boiling point of the doped solvent, causing most of the solvent within the nascent filaments to evaporate, resulting in the solidification of the filaments. After emerging from the tower, these filaments undergo a variety of posttreatments. Dry spinning is slower than melt spinning. Like dry spinning, wet spinning also uses a polymer solution. This polymer solution is extruded through the spinneret into a mixture of solvent and nonsolvent (also called coagulant). Due to the mutual diffusion of solvent and nonsolvent, the polymer solution coagulates to form fibers in the coagulation bath. The coagulated fiber was washed several times to remove the entrapped solvent. Followed by stretching under wet and dry conditions to obtain the required strength .