This study, the rice straw was pretreated with sodium hydroxide as the step of rice straw pretreatment in bioethanol production, and then lignin was recovered by acidification method. The obtained lignin was characterized by Fourier-transform infrared (FT-IR) and X-ray powder diffraction (XRD) to confirm the chemical structure, inorganic matter. To produce sodium lignosulfonate (NaLS), the sulfomethylation was conducted between lignin, formalin, and sodium sulfite. This process was optimized of reaction condition for the best of reaction yield and mass of sodium lignosulfonate by response surface methodology (RSM). The obtained sodium lignosulfonate from the optimal condition was determined by chemical structure and surface tension. |
