The Influence of Reactant Ratio (Eupcalyptus Lignin-Sodium Bisulfite) and Initial pH Towards Characteristics of Sodium Lignosulfonate

Abstract

Eucalyptus lignin was isolatedfrom kraft black liquor through by acidification using H;;SOJ' SulJonation ofeucalyptus lignin produced sodium lignosulJonate (SLS) which can be used as dispersants, and emulsifier. In this research, sulJonation was carried out towards lignin with mass ratio ofeucalyptus /ignin-NaHSOJ (bib) of 1:004, 1:0.5, and 1:0.6, and initial pH of5, 6, 7, 8. Studies on the effect of various ratio ofeucalyptus lignin versus NaHSOJ (J based on wlw) and initial pH of5,6,and 7for the sulJonation reaction showed an increasing yield and improved purity ofSLS obtained However, no significant result was observed on the application of initial pH 7 and 8 toward increasing ofSLS yield and purity. The highest SLS yield of83. 8% with purity of 82.9% was obtained under condition ofinitial pH at 7 and the mass ratio ofeupcayptus lignin over NaHS03 was 1:0.5. The resulted SLS was light brown, water soluble, with pH level between 6.3 and 7.24, and released sulJur-like odor.