Production of Biodiesel Distillate with Low Monoglycerides for B40 Component by Using Distillation Technique with 1 and 30 Plates Column

Abstract

One of the quality standard indicators for biodiesel (fatty acid methyl ester, FAME) product specifications is monoglyceride content. Monoglycerides (MG) are residuals of the vegetable oil reactant that do not react completely in the process of making biodiesel, so that they become contaminants in biodiesel. The lower the monoglycerides in the biodiesel product, the better the quality of the biodiesel. In Indonesia's B40 program, one scenario of adding 10% biodiesel is using FAME distillate on top of 30% regular FAME. The monoglyceride content in the FAME distillate for the B40 mixture was determined not to exceed 0.3 %wt. Distillation technique is one of the effective methods for reducing monoglyceride level in FAME. This study aimed to investigate the effectiveness of laboratory scale distillation with columns of 1 and 30 plates in reducing the monoglycerides concentrations. Refining FAME by true boiling point (TBP) distillation with 30 plates column under 5 mmHg vacuum at reflux ratio of 1; 2-3 showed that monoglyceride levels decreased significantly at the distillate fraction of 240-325 °C, from an initial level of 0.83 wt.% to 0.17 wt.%. Pour point temperature increased 2 times from the original biodiesel pour point temperature. The pour point temperature of distillate fractions of 240-325 °C, 325-330 °C and 330-335 °C were 12 °C, 21 °C and 24 °C, respectively. At the 340-345 °C distillate fraction, the pour point dropped drastically to 3 °C. By using 1 plate distillation column under operating 5 mmHg vacuum at a recovery rate of 90 %v, monoglycerides with an initial level of 0.83 wt.% can be reduced to 0.59 wt.%. distillate recovery. As the recovery rate of distillation level reduced to 86 vol%, the monoglycerides concentration was 0.29 wt.%.