# Study on the Coupling Relationship of Low Temperature Fluidity and Oxidation Stability of Biodiesel
## 3 Experiment Results and Discussion
### Oxidation Stability Experiment Results
#### 3.3.2 Biodiesel Fatty Acid Methyl Ester Data Acquisition  
Oxidation stability and CFPP in biodiesel fuel characteristics are mainly determined by the quality of the feedstock oil, and vary little with the processing process. Consequently, the data for the composition of the 10 biodiesel fatty acid methyl esters in the current research are all from the references [12; 22; 23; 24]. The ten biodiesel are rapeseed oil methyl ester (RME), tea oil methyl ester (TME), soybean oil methyl ester (SME), olive oil methyl ester (OME), peanut oil methyl ester (PNME), jatropha curcas oil biodiesel (JCME), cottonseed oil methyl ester (CSME), Chinese tallow tree seed oil methyl ester (CTKME), corn oil methyl ester (CME) and palm oil methyl ester (PME). Table 2 presents the composition of biodiesel fatty acid methyl ester. For the Cm in the table, n-m represents the number of carbon atoms of the fatty acid group and n stands for the number of double bonds of the fatty acid group. SFAME is the abbreviation for saturated fatty acid methyl ester, SUFAME is the abbreviation for unsaturated fatty acid methyl ester, and PUFA is the abbreviation for polyunsaturated fatty acid methyl ester. Table 3 shows the ten biodiesel's CFPP and OIT. Figure 8: Effects of saturated FAME (fatty acid methyl ester) on low temperature fluidity and oxidation stability of biodiesel. Figure 9: Effects of unsaturated FAME on low temperature fluidity and oxidation stability of biodiesel. 3.3 Effects of Fatty Acid Methyl Ester Composition on the Coupling Relationship between Low Temperature Fluidity and Oxidation Stability of Biodiesel  
The low temperature fluidity and oxidation stability of biodiesel are closely related to the fatty acid methyl ester composition. Through plotting the three influence factors SFAME, SUFAME and PUFA as triangle vertices, the relationship between low temperature fluidity and oxidation stability of biodiesel and fatty acid methyl esters can be obtained. As shown in Figure 10, the CFPP and OIT of biodiesel can be predicted through combining this figure and the composition of biodiesel fatty acid methyl ester. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**FAME** & **RME** & **TME** & **SME** & **OME** & **PNME** & **JCME** & **CSME** & **CTKME** & **CME** & **PME** \\ \hline Methyl laurate & & & & & & & & & & 0.26 \\ (C 12:0) & & & & & & & & & & 0.40 & & 1.09 \\ Methyl myristate & & & & & & & & & & & \\ (C 14:0) & & & & & & & & & & & \\ Methyl palmitate & & & & & & & & & & & \\ (C 22:0) & & & & & & & & & & & \\ Methyl oleate & & & & & & & & & & \\ (C 24:0) & & & & & & & & & & & \\ Methyl myrcene & & & & & & & & & & & \\ (C 12:1) & & & & & & & & & & & \\ Methyl oil & & & & & & & & & & & \\ palmitate & & & & & & & & & & & \\ (C 16:1) & & & & & & & & & & & \\ Methyl oleate & & & & & & & & & & & \\ (C 18:1) & & & & & & & & & & & \\ Methyl & & & & & & & & & & & \\ eicosenoate & & & & & & & & & & & \\ (C 20:1) & & & & & & & & & & & \\ Methyl erucate & & & & & & & & & & & \\ (C 22:1) & & & & & & & & & & & \\ Methyl linoleate & & 22.35 & 8.50 & 53.58 & 10.60 & 35.40 & 66.11 & 62.40 & 31.72 & 55.03 & 8.94 \\ (C 18:2) & & & & & & & & & & & \\ Methyl linoleate & & & & & & & & & & & \\ (C 18:3) & & & & & & & & & & & \\ Total & 92.77 & 99.94 & 99.11 & 99.96 & 100.00 & 99.85 & 100.00 & 100.00 & 99.92 & 100.00 \\ SFAME & 7.32 & 10.94 & 15.66 & 16.00 & 17.00 & 12.05 & 22.20 & 9.49 & 14.13 & 50.60 \\ SU FAME & 56.14 & 80.10 & 23.25 & 71.98 & 47.50 & 21.47 & 15.40 & 17.77 & 29.49 & 40.19 \\ PU FAME & 29.31 & 8.90 & 60.20 & 11.98 & 35.50 & 66.33 & 62.40 & 72.74 & 55.60 & 9.21 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Cold filter plugging point and oxidation induction time of biodiesel.