Glycerolysis of fats and methyl esters

Abstract

Abstract The glycerolysis of methyl esters and triglycerides with crude glycerol, a coproduct from the transesterification of triglycerides, was studied. Three procedures were followed for this conversion. The first procedure was a one‐step glycerolysis with methyl esters. The second procedure was a two‐step process. This procedure involved an initial partial glycerolysis with methyl esters, followed by fat glycerolysis. The third procedure was a simultaneous glycerolysis with methyl esters and triglycerides. In the glycerolysis with methyl esters, the removal of methanol is vital to the production of mono‐ and diglycerides. Methanol was removed either by drawing vacuum on the reactor or by stripping methanol out by means of an inert carrier gas (nitrogen). Different molar ratios of methyl esters to glycerol were tested in the first two processes. At low concentration of methyl esters, total conversion of methyl esters to mono‐ and diglycerides was achieved. As the concentration of methyl esters was increased, the conversion of methyl esters to mono‐ and diglycerides was decreased. Furthermore, the ratio of mono‐ to diglycerides was also higher at lower concentrations of methyl esters. The conversion of triglycerides in the two‐step process with crude glycerol was similar to a one‐step fat glycerolysis with pure glycerol. The composition of different components and the ratio of mono‐ to diglycerides were also comparable.