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