Fatty Acid Methyl Esters (FAME), used as components of biodiesel, are commonly manufactured using a base-catalyzed transesterification process. In this process, triglycerides are converted into FAME and glycerol by reacting with methanol and sodium hydroxide. Multiple factors can affect the reaction efficiency of the transesterification process, including temperature. Many home-processors of biodiesel fuel encourage the 3/27 Conversion Test as an indicator of acceptable reaction efficiency. This test recognizes the miscibility of FAME and methanol to provide a qualitative result of the transesterification process. The 3/27 Conversion Test can be used to determine if a processing variable affected the composition of the reaction product. Materials and processes used in this study were chosen from research of similar processing as well as from previous successful experiments. The processor used in the study is a version of an Appleseed, which is a commonly utilized design by individuals making biodiesel for personal use in approximate batch sizes to those tested in this study. For purposes of this study, nine-25 gallon batches of waste vegetable oil were transesterified into FAME. While all other factors of process and materials were kept continuous, pre-processing feedstock temperature was varied in three stages. Three batches were processed at 110°F, three at 130°F, and three at 150°F. After starting the reaction, samples from the processor were collected at 15-minute intervals. After 60 minutes of processing, four samples for each batch were collected. All samples were tested for completion using the 3/27 Conversion Test. Results were recorded for each temperature and interval. After analyzing the data, no proof was discovered which showed that increasing pre-reaction feedstock oil temperature between 110°F and 150°F increased the likelihood of reacted FAME to pass a 3/27 Conversion Test.
Heisner, Blaine M. "Utilizing the 3/27 Conversion Test to Measure the Effects of Temperature on the Base-Catalyzed Transesterification of Waste Vegetable Oils into Fatty Acid Methyl Esters." The Journal of Automotive Technology and Education (JATE) (Jan 2020).