RECOVERY OF CITRIC ACID FROM FERMENTATION BEER USING SUPPORTED-LIQUID MEMBRANES

Abstract The use of a supported-liquid membrane to separate citric acid from the beer produced by fermentation was studied. The liquid membrane consisted of an organic solution composed of trilaurylamine and a long-chain alcohol dissolved in an inert hydrocarbon solvent that was immobilized in a microporous polypropylene support. Using this membrane, citric acid was recovered from the fermentation beer as citric acid or as its monosodium salt. The effects of temperature, organic solution composition and citric acid concentration on transport rates were investigated. Citric acid flux was greatest under the following conditions: 60°C; trilaurylamine concentration of 38 vol.% in Alkyl Aromatic Oil, or 50 vol.% in Shell Sol 71; and 15 vol.% of n-dodecanol in the membrane as a modifier.