Tin-Catalyzed Esterification and Transesterification Reactions: A Review

Table 7

Main results obtained from soybean oil transesterification with methyl alcohol catalyzed by NaOH, H₂SO₄ or [Sn(II)(3-hydroxy-2-methyl-4-pyrone)₂(H₂O)₂], complex, I catalyst^a, b [11].

Entry	Catalyst^c	Time (h)	Yield (%)^c
1	NaOH	1	0.173
2	NaOH	3	5.135
3	NaOH	6	6.912
4	NaOH	10	9.904
5	H2SO4	1	1.364
6	H2SO4	3	2.201
7	H2SO4	6	4.700
8	H2SO4	10	6.992
9	Sn(II)-pyrone	1	37.139
10	Sn(II)-pyrone	3	91.116
11	Sn(II)-pyrone	6	93.180
12	Sn(II)-pyrone	10	22.125

^aReaction conditions: molar proportions of methanol : oil : catalyst (400 : 100 : 1) were fixed for all experiments, temperature (80°C), stirring magnetic (1000 rpm).
^b[Sn(II)(3-hydroxy-2-methyl-4-pyrone)₂(H₂O)₂], I catalyst.
^cPercent of mass of recovered ester per initial mass of soybean oil.