摘要：Surfactant is a compound that has the ability to lower the interfacial tension between the face of two phases (liquid). The need of surfactant has increased along with the development of the industrial sector. One example is sodium lignosulfonat (SLS) which is useful to improve oil acquisition in its application for EOR (Enhanced Oil Recovery). SLS is a result of the reaction between lignin, NaHSO3(bisulfite) and sodium hydroxide as catalyst. The purpose of this research is to determining the reaction mechanism and determining the value of the reaction rate constant (k). The sulphonation kinetics of lignin was carried out in various temperature (50, 60, 70, 80, and 90°C). From this research obtained a positive (linear) response between sulfonation temperature against reaction rate constants. The lowest k values obtained k50= 2,05 x 10-4minute-1 and the highest one is k90= 3,35 x 10-4. From graphycally calculation obtained the value of A is 0,015 and the energy activation (Ea) is-11,708 kJ/mol with R2= 95,69%. The correlation of the temperature influence to the constant of reaction rate espressed in arhenius equation as follows : k = 0,015 exp(-1408,3/T)
