Effects of Organic Phase, Fermentation Media, and Operating Conditions on Lactic Acid Extraction

Abstract

Lactic acid has extensive uses in the food, pharmaceutical, cosmetic and chemical industry. Lately, its use in producing biodegradable polymeric materials (polylactate) makes the production of lactic acid from fermentation broths very important. The major part of the production cost accounts for the cost of separation from very dilute reaction media where productivity is low as a result of the inhibitory nature of lactic acid. The current method of extraction/separation is both expensive and unsustainable. Therefore, there is great scope for development of alternative technology that will offer efficiency, economic, and environmental benefits. One of the promising technologies for recovery of lactic acid from fermentation broth is reactive liquid-liquid extraction. In this paper the extraction and recovery of lactic acid based on reactive processes is examined and the performance of a hydrophobic microporous hollow-fiber membrane module (HFMM) is evaluated. First, equilibrium experiments were conducted using organic solutions consisting of Aliquat 336/trioctylamine (as a carrier) and tri-butyl phosphate (TBP)/sunflower oil (as a solvent) The values of the distribution coefficient were obtained as a function of feed pH, composition of the organic phase (ratio of carrier to solvent), and temperature (range 8-40°C). The optimum extraction was obtained with the organic phase consisting of a mixture of 15 wt % tri-octylamine (TOA) and 15% Aliquat 336 and 70% solvent. The organic phase with TBP performed best but is less suitable because of its damaging properties (toxicity and environmental impact) and cost. Sunflower oil, which performed moderately, can be regarded as a better option as it has many desirable characteristics (nontoxic, environment-and operatorfriendly) and it costs much less. The percentage extraction was approximately 33% at pH 6 and at room temperature (can be enhanced by operating at higher temperatures) at a feed flow rate of 15-20 L/h. These results suggest that the hollow-fiber membrane process yields good percentage extraction at the fermentation conditions and its in situ application could improve the process productivity by suppressing the inhibitory effect of lactic acid.

Reactive extraction of 3-hydroxypropionic acid from model aqueous solutions and real bioconversion media. Comparison with its isomer 2-hydroxypropionic (lactic) acid

“…The synergistic effect of mixed extractants has been shown to depend on various parameters such as the initial pH of the aqueous solution, the acid concentration and the TOA:Aliquat 336 ratio . These parameters were further tested on 3‐HP reactive extraction.…”

“…21 Most particularly, when active diluents with functional groups such as n-decanol are used, the extraction phase is capable of uptaking acid in excess of which is necessary for the stoechiometric neutralization of the amine. 20 Although the exact mechanism involved is not known, some data suggest that specific hydrogen bonding between the proton of the diluent and the acid-amine complex explains the high solvation power of these diluents, 24,29 a property that is involved in the synergism observed between TOA and Aliquat 336 in n-decanol. Synergistic effects between mixed extractants have been reported for the reactive extraction of 2-HP using tertiary/quaternary alkylamines, 24,36 tri-n-butylphosphate/alkylamines, 31 di-2-ethylhexylphosphoric acid.…”

Quaternary Ammonium and Phosphonium Ionic Liquids in Chemical and Environmental Engineering

“…lactic, levulinic, glutaric, or amino acids (e.g. Uddin et al, 1990;Bora & Dutta, 1998;Kyuchoukov et al, 2005;Harington & Hossain, 2008;Hossain & Maisuria, 2008;Uslu & Kırbaşlar, 2009;Pehlivanoğlu et al, 2010). As an outstanding example the extraction of lactic acid with the bifunctionalized IL Cyphos ® IL 104, should be mentioned.…”

The extraction of lactic acid by emulsion type of liquid membranes using alamine 336 in escaid 100

“…In the last decade, demand for lactic acid production has grown considerably, due to its new application as the monomer of polylactic acid that can be used for the synthesis of biodegradable plastics. As well as being environmentally friendly, there is a growing demand due to strict environmental laws being legislated for biodegradable polymers as a substitute for conventional plastic materials (Coca et al, 1992;Hossain and Maisuria, 2008). Biodegradable copolymers are also for the production of new materials with biomedical applications such as drug delivery systems (Choi and Hong, 1999).…”