Experimental Study on Reactive Extraction of Malonic Acid with Validation by Fourier Transform Infrared Spectroscopy

Malonic acid is an essential carboxylic acid that is used as a backbone reactant in deriving multiple higher-order carboxylic compounds. The successful attempt of producing malonic acid from a biological route has attracted the scientific community to extract malonic acid from a fermentation broth or dilute aqueous stream. Experimental study on the recovery of malonic acid by reactive extraction was performed, and the effects of TBP concentration, diluents (alkane, ketone, and alcohol), and malonic acid concentration were investigated. The equilibrium models (relative basicity and mass action law models) and the number of theoretical units (NTU) were also evaluated. Fourier transform infrared spectroscopy provided evidence for the formation of significant bonds among extractant–diluent–acid complexation systems which support the experimental outcomes. The results of extraction equilibrium are discussed regarding dimerization constant (DMA), partition coefficient (PMA), extraction efficiency (EMA%), distri...