Emulsion Extraction of Bio-products: Influence of Bio-diluents on Extraction of Gallic Acid

Abstract

Natural products and fermentation broths are complex systems. Extraction processes such as emulsion extraction, a process derived from the industrial liquid-liquid extraction, can be used to remove molecules. This chapter presents preview studies dealing with these two processes for bio-products and notably for organic acids from biomass: different parameters were described. Then, a study on eco-conception of these processes for gallic acid with bio-diluents (one hydrogenated terpene and three ethylic fatty acid esters) was presented and compared with results using dodecane, a current petrochemical diluent. A pre-study about eco-conception of liquid-liquid extraction for gallic acid was performed. An extractant as tributyl phosphate (TBP) was necessary, and extraction yield was higher with TBP diluted in ethylic fatty acid esters than in dodecane. So it is possible with esters to reduce the TBP concentration. In extraction by emulsion with the esters as diluents, there was no need of an extractant, gallic acid being slightly soluble in these esters. However, emulsion containing these bio-diluents swelled, which do not exist with dodecane.