Production of Sodium Lignosulfonate (SLS) Surfactant from Oil Palm Empty Fruit Bunches (OPEFB) Using Microwave

The aim of this study was to investigate the effect of using a microwave in synthesizing Sodium Lignosulfonate (SLS) surfactant made of Oil Palm Empty Fruit Bunches (OPEFB) which contains lignin as the content to be processed, especially in the sulfonation process. The observed variables are the NaHSO3 concentration ranging from 0.1 M to 0.7 M, reaction time ranging from 30 minutes to 90 minutes, and microwave power ranging from 300 W to 750 W. on the yield and comparing the results of SLS synthesized with microwave to those obtained through conventional heating methods in the sulfonation process. The process encompassed several steps, including drying, milling, delignification, lignin isolation, and sulfonation using microwaves. Afterward, the SLS results were subjected to analysis through FTIR and HLB testing. The findings revealed a positive correlation between NaHSO3 concentration, reaction time, microwave power, and the yield of SLS Product, with the optimal conditions being at the NaHSO3 concentration of 0.7 M, microwave power of 600 W, and reaction time of 75 minutes. Moreover, the microwave method demonstrated greater efficiency in increasing the SLS Product yield by up to 24% compared to the conventional method.