ABSTRACT Methyl Ester Sulfonic Acid (MESA) is a group of anionic surfactants made through the sulfonation process. Methyl ester sulfonic acid is used to make liquid detergents. In Indonesia, there are not many factories or producers of methyl ester sulfonic acid so that imports are made to meet the needs. Therefore, the processing of methyl ester sulfonic acid is needed to meet the needs of me…