Novel continuous multistage extraction c

A novel separation process, phase transition extraction (PTE), is proposed using solvents with a critical point of miscibility with the feed liquid to be extracted. This process involves alternating heating and cooling across the coexistence curve to obtain either a homogeneous phase or two separate phases. The formation of a homogeneous phase in the mixing stage eliminates the need for intense agitation, and the rapid coalescence on cooling during the settling stage mitigates issues related to the formation of emulsions caused by impurities. The efficiency of the PTE is particularly notable in the extraction of fermentation broths, improving recovery of antibiotics without utilizing centrifuges, thus avoiding the associated costs and potential product damage from shear forces. Experimental studies were conducted with various solvent and solute systems, leading to the observation of solvent distributions post-phase transition and their comparison with equilibrium results. This approach presents significant advantages in scenarios where conventional extraction methods encounter difficulties due to stable emulsions or shear sensitivity, providing an innovative solution for enhancing extraction processes.