Stability of Palm Oil-based Emulsion Liquid Membrane for Succinic Acid Extraction from Aqueous Solution

Abstract

Emulsion liquid membrane (ELM) process has high potential in the separation of succinic from the fermentation broth. However, the major drawback of this technology is the stability of emulsion globules during the extraction process and the chemical involved in the liquid membrane formulation. This study investigate the stability of ELM using a greener formulation containing Amberlite LA-2 as a carrier, Span 80 and Tween 80 as a surfactant, palm oil as a diluent and sodium carbonate (Na2CO3) as an aqueous stripping agent. The emulsion stability was evaluated by observing the water-oil separation of the emulsion and microscopic image of emulsion droplets count and size. Several operating parameters including the organic to internal ratio, homogenizer speed, homogenizing time, and surfactant concentration, and surfactant blend were investigated. The results show the most stable water-in-oil emulsion was observed at 3:1 organic to internal ratio; 7000rpm homogenizer speed; 5 minute emulsification time; 3% (w/v) surfactant at HLB 8. Besides, the extraction study shows 70% of the succinic acid was extracted at 0.01M Na2CO3, 1:3 treat ratio, and 0.7M Amberlite in palm oil at optimum primary emulsion stability conditions. This indicates the potential of using palm oil based ELM for the extraction of succinic acid.