Monitoring the conversion of soybean oil to methyl or ethyl esters using the refractive index with correlation gas chromatography

作者：Santos Regina C R; Vieira Romulo B; Valentini Antoninho^*

来源：Microchemical Journal, 2013, 109: 46-50.

DOI：10.1016/j.microc.2012.05.001

• Biodiesel
• Transesterification
• Soybean oil
• Refractive index
• Gas chromatography

A simple method (refractive index) was applied to monitor the progress and the end point of the transesterification reaction of soybean oil to biodiesel (methyl or ethyl esters). Additionally, the same method may be used to determine the methyl or ethyl ester content during the transesterification reaction progress. To do so, blends of biodiesel and soybean oil were prepared at different wt.% to obtain a simple linear correlation with the refractive index and a correlation coefficient (R-2) of 0.9997 and 0.9996 for the FAMEs and FAEEs, respectively. The transesterification process of soybean oil with methanol and ethanol was performed to determine how the refractive index properties change due to the ratio of conversion. It was concluded that in the reaction kinetics of the methanolysis reaction, the efficiency was over 90% in 8 h. Compared with existing chromatographic techniques, the refractive index method for monitoring the transesterification of vegetable oils presented good results. Additionally, the method was rapid, inexpensive and especially suitable for process control applications.

• 出版日期2013-7