In sulfite pulping, wood is reacted with sulfur dioxide (SO2), which then combines with water to generate sulfonic acid and bases like calcium, sodium, magnesium, or ammonium. This reaction occurs at temperature between 125°C and 150°C and lasts three to seven hours. During the pulping process, this procedure uses acid catalysis to cleave α-and β-ether bonds. Dissolving and separating lignin in an aqueous solution is possible by adding sulfonic acids to the ether linkage's alpha-carbon. The functional groups like lignosulfonate, carboxylic, and phenolic/aliphatic hydroxyl groups are present in resultant lignin. Also, it is hydrophilic because of the high sulfonate concentration. The sulfite procedure yields lignin with a relatively high ash concentration and a broad molecular weight dispersion. While the sulfonate level can reach up to 13%, on the other hand, only 4% of carboxyl acid is present. Thus, fodder, particle boards, surface active agents, adhesives, cement additives, stabilizers and dispersants are the applications of lignin extracted from sulfite pulping .