Zwitterionic Buffering Agent as an Alternative to Improve Carboxylic Acid Extraction Performance with 1-heptanol Solvent

Separation of carboxylic acids by liquid-liquid extraction method using 1-heptanol solvent and the addition of EPPS biological buffer was studied in this research. Liquid-liquid equilibrium (LLE) data on carboxylic acid systems (butyric acid/propionic acid), water, 1- heptanol, biological buffer EPPS at 303.15 K and atmospheric pressure were obtained. Experimental data were correlated well using the NRTL model with the RMSD below 1%. Based on experimental data, the effect of adding EPPS biological buffer can increase extraction performance as indicated by the value of separation factor (S) of butyric acid increasing two times higher, while separation factor values of propionic acid can be increased 4 times higher than the system without EPPS biological buffer. These results can be used as a reference for the design of the extraction column in the carboxylic acid extraction process so that the extraction process can run more efficiently and optimally.