| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for sulfonating a fatty acid ester or its derivative into a scarcely colored product substantially without producing by-products, to provide a method for bleaching the product, and to provide a method for neutralizing the product. SOLUTION: A fatty acid alkyl ester raw material is sulfonated in a falling liquid film type reactor 12 in a sulfonating section 10, and the sulfonated crude product is bleached in the coexistence of an alcohol in an amount of up to about 40 wt.% based on the weight of the crude product in a circuit 34 in a bleaching system 32. The process for the bleaching/alcohol addition is carried out in a non-metal apparatus or an alloy-made apparatus scarcely containing iron at a temperature of >=90 deg.C. The obtained product is then neutralized with a liquid base or a metal carbonate salt. |
