Esterification of Mixed Carboxylic-fatty Anhydrides Using Amberlyst-15 as Heterogeneous Catalyst.
The article deals with the use of mixed anhydrides for the synthesis of fatty esters. Both aliphatic and aromatic acids are involved, indicating different behaviors according to the chain length of the aliphatic acid. We describe a novel and efficient method for the synthesis of fatty esters by the esterification reaction of primary, secondary and tertiary alcohols with mixed carboxylic-palmitic anhydrides using resin Amberlyst-15 as heterogeneous acid catalyst. Influence of various reaction parameters such as molar ratio (anhydride/alcohol), catalyst amount, type of alcohol and type of mixed anhydride were studied to optimize the conditions for maximum yield. Among tested anhydrides we quote mainly the 4-chlorobenzoic palmitic anhydride because it was both reactive and selective for the preparation of palmitic acid ester. This anhydride gave a good yield of palmitic ester.
Synthesis of Sucrose Fatty Acid Esters by Using Mixed Carboxylic-fatty Anhydrides.
Fatty acid sugar esters are non-ionic surfactant active agents with excellent performance and many uses. This work is devoted to the synthesis of sugar esters by the esterification reaction of sugar with mixed carboxylicpalmitic anhydrides using resin Amberlyst-15 as heterogeneous acid catalyst. These anhydrides should be stable and react as acylating agents. Influence of different reaction parameters, such as the molar ratio (sucrose/anhydride), the type of solvent and the reaction time on the yield of the esterification reaction were studied. The esterification reaction of sucrose with mixed palmitic benzoic anhydride leads to a mixture of sucrose esters of palmitic acid with a good percentage of conversion. The mixed anhydride was both reactive and selective for the preparation of fatty acid ester.
Extraction rates of oil from high oleic sunflower seeds with supercritical carbon dioxide
Abstract Supercritical CO 2 extraction of oleic sunflower seeds was shown to be effective and yielded a product very similar to pure refined oil. In our work extraction pressure was restricted to 250 bar, due to technical constraints, and for this pressure, a temperature increase (up to 60 °C) was observed to be detrimental. Grinded seeds were used, segregated into average small particles (0.25 mm), and average large particles (1.25 mm), the extractable oil content of the latter being smaller. In relation to particle size, differences in extraction rates and yields were observed. Modelling using conventional models was attempted and Sovova's model, which considers accessible and inaccessible oil content, appeared to be the most adequate.