Liquid−Liquid Extraction Using the Composition-Induced Phase Separation Process

This paper describes a new separation process of liquid−liquid extraction. It consists of first mixing the system to be extracted with a primary solvent, which is soluble with the native solvent, and subsequently adding a modifier, which is insoluble with either the native or the primary solvent. This process is similar to the phase transition extraction, which was described in a previous paper, where the liquid mixture, together with the solute to be separated, is first heated above its critical temperature, where it forms a uniform solution, and then cooled to the region below the miscibility curve, where it separates. Both processes have the advantage that the resulting separation of the solvents is very rapid, even in the presence of emulsion-forming impurities. In addition, the extraction efficiency of the new process may be 10 times higher than that of the traditional liquid−liquid extraction. The new process is thought of having significant advantages in the extraction of products from fermentation broths, plants, and other natural sources.