PROCESS INTENSIFICATION: PARASTILLATION APPLYED TO THE FATTY ACID ETHYL ESTER SEPARATION

Ethyl esters can be used in the fatty acid production and in the emulsifiers generation by the interesterification with sucrose. The purification of ethyl esters present commercial advantages due to their physical properties. Distillation is an alternative to obtain purified ethyl esters, however, it is high energy intensive. The energy consumption and/or the material cost may be reduced by the phase division inside distillation columns. Parastillation considers the vapor flow division into two or more ascending and parallel streams, which contact with a single downward liquid stream. The parastillation structure enables the arrangement of a larger number of stages per column height, keeping the same tray spacing used in conventional distillation columns. In fact, a parastillation column with two vapor divisions presents almost twice the number of stages than a conventional distillation column of same height. This increase in the number of stages, keeping the same height, allows a reduction in capital and/or operational costs. In this context, the aim of this work is to present the parastillation as an alternative to purify ethyl esters. The conventional distillation and the parastillation processes were simulated by the McCabe-Thiele methodology and a proposed adaptation of this method, respectively. To represent the palm oil ethyl esters, only palmitic and oleic acids were considered (83% w/w of the fatty acids that constitute palm oil triacylglycerols). Results demonstrated that, maintaining constant the column height, conventional distillation processes can be replaced by parastillation, columns with two and three vapor divisions, resulting into energy savings up to 21% and 26%, respectively. However, maintaining the same energy consumption, the parastillation column, with two and three phase divisions, may be, respectively, 20% and 28% lower than the equivalent traditional one. These results indicate that parastillation columns may be analternative to reduce operational and/or capital cost in ethyl ester purification.