The book concern with delignification of of black liquor with cook and pulp process from Crotalaria juncea (sunn hemp) fibre. Lignocellulose is the most abundant biomass, representing nearly 70% of the total plant biomass. The removal of the structural polymer lignin from plant tissue is known as Delignification which can be used for applications i.e. paper making. The chemical and mechanical process are used for the removal of pulp from wood.