METHOD FOR LOWERING POUR POINT OF BIODIESEL, AND BIODIESEL WHOSE POUR POINT HAS BEEN LOWERED BY MEANS OF THE METHOD

摘要

The present invention relates to a method for lowering the pour point of biodiesel, and, more specifically, a feature of the invention is that it comprises (1) a step of eliminating water from an oil/fat via a dehydration reaction, (2) a step of producing a methyl ester and glycerol by means of an ester-exchange reaction between the dehydrated oil/fat and methanol, (3) a step of producing CH₂=C(CH₃)-COOR from the glycerol, (4) a step of mixing a C5 to C12 alkylbenzene into the CH₂=C(CH₃)-COOR, and (5) a step of mixing the product of step (4) and the methyl ester; where the "R" in the "CH₂=C(CH₃)-COOR" is a C5 to C12 alkyl group. Another aspect of the invention is that it provides a biodiesel whose pour point has been lowered by means of such a method. The method for lowering the pour point of a biodiesel proposed by the present invention makes it possible to lower the pour point of the biodiesel in a process in which the biodiesel is made from an oil/fat without adding any other chemicals and without mixing with an existing light oil; this being because the invention comprises (1) the step of eliminating water from the oil/fat via the dehydration reaction, (2) the step of producing the methyl ester and glycerol by means of the ester-exchange reaction between the dehydrated oil/fat and methanol, (3) the step of producing CH₂=C(CH₃)-COOR from the glycerol, (4) the step of mixing the C5 to C12 alkylbenzene into the CH₂=C(CH₃)-COOR, and (5) the step of mixing the product of step (4) and the methyl ester, and being because the invention also comprises a step, between step (1) and step (2), of producing a methyl ester by subjecting the free fatty acids comprised in the oil/fat to an esterification reaction with methanol. Also, the present invention can provide biodiesel whose pour point has been lowered by means of such a method.