Optimizing Process Parameters of Epoxidized Sucrose Soyate Synthesis for Industrial Scale Production

Abstract

There is a growing need to produce epoxidized sucrose soyate (ESS) at an industrial scale for large-scale applications in coatings and material science. Industrial scale production of ESS requires optimization of the process conditions to minimize cost without compromising resin quality. Therefore, a robust model was developed that predicts the conversion of double bonds to oxirane under different process scenarios. Data for the model were obtained by epoxidizing 30 g batches of sucrose soyate at three reactor temperatures (55, 60, and 65°C), three molar ratios of acetic acid to oil unsaturation (0.25:1, 0.375:1, and 0.5:1), three molar ratios of H 2 O 2 to oil unsaturation (1:1, 1.5:1, and 2:1), three catalyst amounts (1.5, 3.75, and 6 g), and three reaction times (3.5, 4.5, and 5.5 h). The model was highly significant with an adjusted R 2 of 97.6% and predicted R 2 of 96.8%. The root-mean-square errors (RMSE) of 0.54 showed that the model was a good fit in predicting optimal epoxidation conditions at different process levels. ESS samples epoxidized at 60−65°C for 4.5−5 h had conversion greater than 98% even when reagent amounts were reduced by 18−20%. A similar resin quality was also attained when one of the optimal conditions was scaled-up 100 fold to a 3 kg batch. Therefore, this model can be used to determine appropriate processing conditions for epoxidizing vegetable oil-based compounds at any scale with sufficient mixing and temperature control.

Optimization of the epoxidation of linseed oil using response surface methodology

“…The predicted optimal values of the process conditions differed among the studies, although, in some cases, the carboxylic acid, the concentration of hydrogen peroxide solution, as well as the type of the catalyst were the same and the investigated ranges of the process conditions were similar. Examples include the significant difference between the predicted optimal values of the reaction temperatures for the epoxidation of sucrose soyate [25] and castor oil [24]. For more unsaturated sucrose soyate, the optimal value of the reaction temperature (65 °C) was the highest one in the investigated range of 55-65 °C [25], while for castor oil the optimal value (52.81 °C) was close to the lowest temperature of the investigated range of 50-70 °C [24].…”

“…More recently, experimental designs and statistical analyses have been employed to evaluate the effects of and to optimize the epoxidation process conditions. Response surface methodology, a statistical method often used in chemical and biochemical engineering, was employed to optimize the epoxidation of vegetable oils such as rapeseed oil [21][22][23] and castor oil [24], as well as vegetable oil derivatives such as sucrose soyate [25] and methyl esters derived from castor oil [26], jatropha oil [27], and waste cooking oil [28]. Besides reducing the required experimental work, this approach enables not only the determination of the process conditions for reaching the highest epoxy yield, but also the evaluation of an interactive effect among the process conditions.…”

“…Besides reducing the required experimental work, this approach enables not only the determination of the process conditions for reaching the highest epoxy yield, but also the evaluation of an interactive effect among the process conditions. Previous studies on epoxidation have been conducted with peracetic acid generated in situ in the presence of either sulphuric acid [21,22] or the ion exchange resin Amberlite IR-120H [24][25][26]28] as the catalyst, with the exception of the epoxidation of rapeseed oil [23] and methyl esters derived from jatropha oil [27] which was conducted with performic acid. The effects of two [23], four [21,22,24,[26][27][28], or five [25] process conditions including the reaction temperature, hydrogen peroxide-to-oil unsaturation mole ratio, carboxylic acid-to-oil unsaturation mole ratio, catalyst amount, and reaction time, on the epoxy yield were analyzed in these studies.…”

“…The response surface methodology was combined either with the central composite [21-23,24,26--28] or with the Box-Behnken [25] experimental design. Statistical analysis of the reported experimental data confirmed that all investigated conditions are significant for the epoxidation process in the applied ranges.…”

“…Statistical analysis of the reported experimental data confirmed that all investigated conditions are significant for the epoxidation process in the applied ranges. Second-order polynomial equations were used in all studies for the prediction of either the relative epoxy yield [21,22,25,27] or the epoxy oxygen content [21][22][23][24]26,28]. In the developed models, i.e., regression equations, used for the calculation of the optimal process conditions, the linear and quadratic terms were statistically significant, while in some of the studies either a few [27] or all [23,25] interaction terms were found insignificant.…”