Enzymatic Synthesis of Fatty Acid Isoamyl Monoesters from Soybean Oil Deodorizer Distillate: A Renewable and Ecofriendly Base Stock for Lubricant Industries

Abstract

In this study, soybean oil deodorizer distillate (SODD), a mixture of free fatty acids and acylglycerides, and isoamyl alcohol were evaluated as substrates in the synthesis of fatty acid isoamyl monoesters catalyzed by Eversa (a liquid formulation of Thermomyces lanuginosus lipase). SODD and the products were characterized by the chemical and physical properties of lubricant base stocks. The optimal conditions to produce isoamyl fatty acid esters were determined by response surface methodology (RSM) using rotational central composite design (RCCD, 23 factorial + 6 axial points + 5 replications at the central point); they were 1 mol of fatty acids (based on the SODD saponifiable index) to 2.5 mol isoamyl alcohol, 45 °C, and 6 wt.% enzymes (enzyme mass/SODD mass). The effect of the water content of the reactional medium was also studied, with two conditions of molecular sieve ratio (molecular sieve mass/SODD mass) selected as 39 wt.% (almost anhydrous reaction medium) and 9 wt.%. Ester yields of around 50 wt.% and 70 wt.% were reached after 50 h reaction, respectively. The reaction products containing 43.7 wt.% and 55.2 wt.% FAIE exhibited viscosity indices of 175 and 163.8, pour points of −6 °C and −9 °C, flash points of 178 and 104 °C, and low oxidative stability, respectively. Their properties (mainly very high viscosity indices) make them suitable to be used as base stocks in lubricant formulation industries.

Sustainable Biocatalytic Synthesis of a Second-Generation Biolubricant

“…Table 4 shows the results obtained for the product synthesized (0.985 purity) in a reaction developed at optimal conditions with a 0.985. Upon comparing the viscosity index of the ester under study with those of other biolubricants described in the consulted bibliography [11][12][13]16,17,21,26,29,30], it is evident that the value calculated in this work (204.43) falls within the range of those found in the studies of other researchers (above 150). Therefore, it can be concluded that this ester is good enough for use as a biolubricant because it maintains its viscosity over a broad temperature range, ensuring consistent performance and protection against wear and tear, even in extreme conditions.…”

“…To date, biocatalytic synthesis has been extensively developed. The esterification and transesterification of a wide variety of fatty acid-composed materials with different alcohols and poliols (methanol, neopentyl glycol, isoamyl alcohol, trimethylolpropane, pentaerythritol and fusel oil) have been catalyzed by lipases, both free and immobilized, from different sources, in solvent-free systems to yield first-generation biolubricants [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Enzymatic Synthesis of Thymol Octanoate, a Promising Hybrid Molecule

“…Different experimental conditions were explored to minimize enzyme inhibition and optimize ester production. All reactions were carried out in solvent-free systems, which make this synthesis methodology even more attractive from economic and environmental points of view [69][70][71][72].…”

Trends in the Use of Lipases: A Systematic Review and Bibliometric Analysis

“…These properties of lipases demonstrate their good performance when applied in biocatalysis in the most diverse processes [ 4 ]. For example, in studies on biolubricants [ 7 ], the synthesis of glycerin monostearate [ 8 ], biosurfactant production [ 9 ], in the pretreatment of industrial [ 10 ], in the production of new nanobiocatalysts [ 11 ], and in the modification of cheese by enzymes [ 12 ].…”