METHOD FOR PRODUCING FATTY ACID LOWER ALKYL ESTER

A METHOD FOR PRODUCING LOWER ALKYL ESTERS OF FATTY ACIDS FROM A MATERIAL CONTAINING AN ANIMAL OR VEGETABLE FAT AND OIL, THE METHOD INCLUDING AN ESTERIFICATION STEP (A) IN WHICH FATTY ACIDS IN THE MATERIAL ARE ESTERIFIED WITH A LOWER ALKYL ALCOHOL USING A CATION EXCHANGE RESIN TO OBTAIN A REACTION MIXTURE CONTAINING AN ESTER-MIXED OIL HAVING AN ACID VALUE OF 2 OR LESS; A TRANSESTERIFICATION STEP (B) WHICH INCLUDES AT LEAST A FIRST INTERMEDIATE STEP TO TRANSESTERIFY A FAT AND OIL IN THE ESTER-MIXED OIL WITH A LOWER ALKYL ALCOHOL WHILE ADJUSTING AN AMOUNT OF AN ALKALINE CATALYST WITHIN A RANGE OF 0.1 TO 1 PARTS BY MASS RELATIVE TO 100 PARTS BY MASS OF THE ESTER-MIXED OIL BASED ON THE ACID VALUE; A DISTILLATION STEP (C) IN WHICH A DISTILLATE THAT CONTAINS A GROUP OF LOWER ALKYL ESTERS OF FATTY ACIDS HAVING A SMALLER NUMBER OF CARBON ATOMS IS REMOVED BY DISTILLATION FROM AN OIL PHASE OBTAINED IN THE TRANSESTERIFICATION STEP (B), THEREBY RETAINING A RESIDUE THAT CONTAINS A GROUP OF LOWER ALKYL ESTERS OF FATTY ACIDS HAVING A LARGER NUMBER OF CARBON ATOMS; AND A FRACTIONAL DISTILLATION STEP (D) WHICH INCLUDES AT LEAST A STEP TO SEPARATE A GROUP OF LOWER ALKYL ESTERS OF FATTY ACIDS HAVING A LARGER NUMBER OF CARBON ATOMS CONTAINED IN THE RESIDUE INTO DIFFERENT FRACTIONS BASED ON THE NUMBER OF THEIR CARBON ATOMS BY DISTILLATION. (FIG. 1)