Extraction optimization of organic compounds by demixing observed in the H2O–NaOH–piperidine ternary diagram

Abstract

Three isothermal sections of the isobaric ternary system H2O–NaOH–C5H10NH were determined by Isoplethic Thermal Analysis at 293, 313, and 323 K. Miscibility gaps were completely delimited and each critical point was calculated. This system is then characterized by a prevalent miscibility gap, three crystallization domains and two triphasic invariant domains. The relevant exploitation of this diagram so permits us to deduce the demixing temperature leading to the optimal transfer of the organic compounds in the light phase and also the composition of the organic phase recovered after this second step of extraction. Moreover, the addition of calculated quantities of sodium hydroxide aqueous solution allows to be in optimized conditions for the next distillation operations.