The invention relates to a surfactant used in the production of washing
powder, in particular to a method for producing
sodium fatty acid methyl
ester sulfonate, which solves the problem that the prior art cannot realize continuous, stable industrialized
mass production. Hydrogenated palm-
methyl stearate is adopted as material, and is sulfonated by SO3 gas on a multi-tube film reactor, steps, such as aging, reesterification, dealcoholization,
neutralization, bleaching and
vacuum drying, are then sequentially carried out, so that
sodium fatty acid methyl
ester sulfonate product is obtained, the content of MES is more than 80 percent, the content of disodium salt is less than 5 percent, the content of free oil is less than 2.5 percent, the content of
sodium methyl sulfate is less than 8 percent, and color is less than 60 klett(5 percent A.M). Because
highly selective catalyst is added in the aging process, the production of deep-
colored by-product is reduced; because the reesterification reaction and the bleaching reaction are separately carried out, the safety of reaction is enhanced, and the consumption of
methanol as
solvent is greatly reduced; because vacuum dealcoholization is carried out before sulfoacid
neutralization, industrialized operation can be easily carried out, and meanwhile, the safety problem of
methanol in the subsequent bleaching step is eliminated.