Method for preparing fatty acyl amino acid surfactants

The invention relates to a synthesis method for preparing fatty acyl amino acid surfactants in a packed bed reactor by taking fatty acid esters as raw materials. The method is that low-carbon monohydric alcohol solutions of fatty acid esters and catalysts are filled in an amino acid sodium bed in the packed bed reactor under hot-press conditions to react to prepare fatty acyl amino acid sodium. According to the invention, use of acyl chloride is avoided in the raw materials to improve greenness of the raw materials, and the raw materials are low in cost, readily available and good in economy; formation of sodium chloride by-products is avoided to improve the atom economy of the reaction; the amino acid sodium with a high ratio participates in the reaction to improve the reaction yield; the technological process is free of corrosion, low in pollution, and environment-friendly; the method disclosed by the invention is consistent with the principles of green chemistry and a cleaner production process for replacing the traditional Schotten-Baumann synthesis method.