| 摘要 |
A method allowing, from natural fat or oils, or from other glyceride mixtures, to obtain fatty acid ethyl esters that can be used as gas oil substitutes, comprises: stage (a) oil, fat or a glyceride mixture is transesterified by ethanol using a soluble catalyst or a catalyst that becomes soluble during the reaction; stage (b) resultant glycerin is decanted and removed, without requiring an excess ethanol evaporation operation, stage (c) a second transesterification is conducted to obtain a product whose ester content is at least 97% by mass, stage (d) evaporation of excess ethanol is carried out in the presence of the catalyst under suitable conditions preventing a reverse transesterification reaction, the resultant ethanol being practically anhydrous, stage (e) the ester undergoes purification by water wash sequences, and stage (f) the ester is dried under reduced pressure.
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