## 3 Results and Discussion
[PERSON] and [PERSON] [31] attained 95 wt.% conversion in methyl esters in about 240s of reaction in batch reactor while [PERSON] and [PERSON] [36] also reported conversions of around 90 wt.% in 30 min reaction for methyl esterification of oleic acid in continuous mode. The amount of glycerol and non-ester composition is much less, which results in higher amount of product in the biodiesel range. The presence of glycerol in solution helps drive the equilibrium towards reactant, lowering the yield of esters [39]. The non-ester component and glycerol collectively is less than 5% for both SCM and SCE. ==ERROR: No output for this page== \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & & & \multicolumn{8}{c}{**Esters**} \\ \hline  & & & \multicolumn{8}{c}{0 min} & \\ M.R & Glycerol & C10.2 & C12.0 & C16.0 & C17.0 & C18.0 & C19.1 & C20.1 & C20.2 & C20.3 & Non-esters \\
1.6 & - & - & 0.34 & - & - & 16.15 & - & 37.11 & 43.37 & 3.03 & 0.00 \\
1.12 & - & 0.45 & 0.04 & - & - & 16.50 & - & 37.63 & 42.10 & 2.96 & 0.32 \\
1.18 & - & 0.78 & - & - & - & 17.75 & - & 37.25 & 39.83 & 4.15 & 0.24 \\ \hline  & & & \multicolumn{8}{c}{15 min} & \\
1.6 & - & - & - & - & - & 16.33 & - & 36.78 & 43.20 & 3.50 & 0.19 \\
1.12 & 1.44 & 0.18 & 0.08 & 0.23 & 0.30 & 15.75 & 0.72 & 37.38 & 38.86 & 4.67 & 0.39 \\
1.18 & - & - & - & 0.28 & - & 13.31 & - & 35.63 & 41.60 & 5.53 & 3.65 \\ \hline  & & & \multicolumn{8}{c}{30 min} & \\
1.6 & - & - & 0.61 & 0.13 & - & 16.53 & - & 37.06 & 40.76 & 4.91 & 0.00 \\
1.12 & 2.00 & 0.11 & - & 0.24 & 1.70 & 13.90 & 4.15 & 36.54 & 35.77 & 4.38 & 1.21 \\
1.18 & 3.94 & - & - & 0.21 & - & 13.18 & - & 35.49 & 41.06 & 5.41 & 0.71 \\ \hline  & & & \multicolumn{8}{c}{45 min} & \\
1.6 & - & - & - & 0.16 & - & 16.08 & - & 37.16 & 40.71 & 4.90 & 0.99 \\
1.12 & 2.15 & - & 0.32 & 0.25 & 0.13 & 14.65 & - & 36.33 & 39.64 & 5.13 & 1.40 \\
1.18 & 3.95 & - & - & 0.21 & - & 13.43 & - & 35.55 & 41.43 & 5.42 & 0.01 \\ \hline  & & & \multicolumn{8}{c}{60 min} & \\
1.6 & 0.93 & - & 0.08 & 0.22 & - & 15.78 & - & 37.19 & 40.63 & 4.86 & 0.31 \\
1.12 & 4.21 & - & - & 0.23 & - & 13.58 & - & 35.66 & 39.74 & 5.73 & 0.85 \\
1.18 & 4.20 & - & 0.17 & 0.21 & - & 13.23 & - & 35.38 & 40.37 & 5.62 & 0.82 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Product composition according to carbon number on varying molar ratio for SCE at transesterification temperature of 290 \({}^{\circ}\)C.  
The difference in the product obtained while using SCM and SCE is still ambiguous as shown by many researches [32; 41; 42]. Numerous studies [23; 30] have shown the suitability of SCM in biodiesel production, while studies by [PERSON] et al. [29] and [PERSON] and [PERSON] [43] have presented the suitability of SCE over SCM. Thus, this field still needs deeper and concrete comparative studies. From an environmental point of view, the requirement of methanol makes the current biodiesel product not totally 100% renewable as methanol is derived from fossil-based products. Ethanol, on the other hand, can be produced from agricultural biomass via fermentation technology and is easily available in the market at high purity [44]. However, if ethanol is produced from cash or edible crops, it poses threat to the human civilization. Therefore, detail analysis considering the pros and cons of SCM and SCE is required before concluding the superiority of one or the other. However, the cost factor and availability plays crucial role for selecting either SCM or SCE.