Performance of Liquid Eversa on Fatty Acid Ethyl Esters Production by Simultaneous Esterification/Transesterification of Low-to-High Acidity Feedstocks

José Renato Guimarães,Paulo Waldir Tardioli,Ana Carolina Vieira,Angelica Marquettotti Salcedo Vieira,Ana Bárbara Moulin Cansian,Roberto Fernandez-Lafuente

doi:10.3390/catal11121486

José Renato Guimarães, Paulo Waldir Tardioli + Show 4 more

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https://doi.org/10.3390/catal11121486

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Abstract

Liquid Eversa was evaluated in hydrolysis of acylglycerols from soybean oil deodorizer distillate (SODD), as well as simultaneous esterification/transesterification of SODD with low-to-high free fatty acids (FFAs) content using ethanol as acyl acceptor. Hydrolysis of SODD at mild temperature (37 °C) and without pH control (water:SODD mass ratio of 4:1) increased its FFAs content from 17.2 wt.% to 72.5 wt.% after 48 h reaction. A cold saponification of SODD allowed a saponification phase (SODD-SP) to be recovered with 93 wt.% saponification index and 2.25 wt.% FFAs content, which was used to find the experimental conditions for simultaneous esterification/transesterification reactions by experimental design. Temperature of 35 °C, enzyme concentration of 8.36 wt.%, and molar ratio of 3.64:1 (ethanol:SODD-SP) were found as the best conditions for fatty acid ethyl esters (FAEEs) production from SODD-SP (86.56 wt.% ester yield after 23 h reaction). Under the same reaction conditions, crude SODD (17.2 wt.% FFAs) and hydrolyzed SODD (72.5 wt.% FFAs) yielded products containing around 80 wt.% FAEEs. Caustic treatment could increase the ester content to around 90 wt.% and reduce the FFAs content to less than 1 wt.%. Our results show the good performance of liquid Eversa in aqueous (hydrolysis reactions) and organic (esterification/transesterification reactions) media.

Highlights

There is in the market a low-cost liquid lipase (Eversa Transform, a variant lipase fromThermomyces lanuginosus) specially formulated for the biodiesel industry [1,2,3,4]
As the soybean oil deodorizer distillate (SODD) is a by-product of oil refining, its composition depends on the oil source and the processing steps
The physical-chemical properties of the SODD (Table 1) show a saponification index (181.62 ± 0.96 mg KOH/g) close to that reported by Yin et al [31,32] (154.87 mg KOH/g ± 2.62), who used SODD for biodiesel production

Summary

Introduction

There is in the market a low-cost liquid lipase (Eversa Transform, a variant lipase fromThermomyces lanuginosus) specially formulated for the biodiesel industry [1,2,3,4]. The SODD is a by-product of the soy oil refining, generated in the oil deodorization step [20] that is carried out to remove volatile compounds responsible for unacceptable odor, color and taste in the quality standard of oils for commercialization [20,21]. Due to the high content of saponifiable materials (up to 90 wt.%), deodorizer distillates (DDs) of vegetable oils (soy, palm, rapeseed, etc.) have been exploited as raw material for biodiesel production (Table A2 in Appendix A) [25,26,27,28,29,30], reaching ester yields from 88% to about 98%, mainly using commercial immobilized lipases (Lipozyme IM, Novozym 435 and Lipozyme RM-IM) [25,26,27,28,29,30]. According to our research in the scientific literature, there are still no works on the production of fatty acids ethyl esters (FAEEs) from SODD using liquid Eversa

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