Lactic acid, adsorption

Davison, B. H., and Scott, C. D., A Proposed Bioparticle Fluidized-Bed for Lactic Acid Fermentation and Simultaneous Adsorption, Biotechnol. Bioeng., 39 365 (1992)... 

Sosa, A.V., Ochoa, J. and Perotti, N.L, Modeling of direct recovery of lactic acid from whole broths by ion exchange adsorption. Bioseparation, 9 (2000) 283-289. 

The lower GO conversion rate in water could arise via several conditions. If GO is competing for adsorption sites on the catalyst surface with solvents, it may do so more successfully against i-PrOH and t-BuOH than against water because the -OH groups in GO are all less shielded than the ones in i-PrOH and t-BuOH. This is further supported by the low lactic acid yields of reactions run in these alcohols. 

Rhizopus oryzae was immobilized in polyurethane foam cubes by Sun et al. -" The effects of the cube size on cell immobilization, cell growth and L(-i-)-lactic acid production were studied, limnobilization was accomplished by simple adsorption. The use of small cubes for R. oiyzae immobilization was very effective in increasing the productivity of L(-t-)-lactic acid by the immobilized cells. The inoculum size was effective for increasing the immobilization ratio (ratio of the number of cubes containing cells to the total number of cubes). We discussed mass transport problems of polyurethane foam and how the application of certain composite technologies mitigates this difficulty earlier in this chapter. 

Many industrial organic acids can be produced by fermentation, such as acetic, citric, and lactic acids. Succinic acid is a dicarboxylic acid of potential industrial interest as a platform chemical (1-3). Separation and purification of succinic acid by adsorption was tested to replace current precipitation methods and their associated waste disposal problems. Succinic acid is a valuable intermediate value chemical with a moderate market. For succinic acid to have an economic and energy impact, it will need to become a commodity chemical intermediate with a much lower price. This target price hasbeen estimated to be between 0.22 and 0.30 / lb ( 0.48- 0.66/kg) and is potentially achievable with advanced technology (1). At this price, succinic acid can be catalytically upgraded into other higher valued chemicals suchastetrahydrofuran, 1,4-butanediol, y-butyrolactone, 2-pyrrolidinone, and N-methylpyrrolidinone. 

It appears that the CHOH-COOH group, or the CO-COOH group, promotes adsorption on the lactic acid centre, while the CH2-COOH group favours adsorption on the succinic acid centre. An exception was found in mesotartaric acid, HOOC CHOH CHOH-COOH, which seems to be adsorbed on both centres and the phenyl propionic acid had some tendency to be adsorbed on the lactic acid centre also. 

Verrecchia,T., Huve, P., Bazile, D., Veillard, M., Spenlehauer, G., and Couvreur, P. (1993), Adsorption/desorption of human serum albumin at the surface of poly(lactic acid) nanoparticles prepared by a solvent evaporation process,/. Biomed. Mater. Res., 27(8), 1019-1028. 

Leonard, R.H., Peterson, W.H., Johnson, M.J. (1948) Lactic acid from fermentation of sulfite waste liquor. Ind. Eng. Chem. 40, 51-61. Leopold, A.C., van Schaik, R, Neal, M. (1960) Molecular structure and herbicide adsorption. Weeds 8, 48. 

Several methods have been explored for the economical recovery of lactic acid from fermentation broth including extraction with solvent, electrodialysis, ion-exchange adsorption (see [14] for review), and reverse osmosis [15]. Wang et al. 

Because amino groups act autocatalytically (15-17) in the presence of water, for acid catalysis an excess of HC1 was used to overcompensate the formation of -NH3+C1 . In these cases, the gels were washed with methanol and water until no Cl" could be detected in the filtrate. How far the incorporation of amino groups into silica could affect the adsorption of acid components was of interest. Lactic acid and a sulfonic acid (a commercially available dye named Telon Light Yellow) were chosen as test components (18). In Figure 7 the adsorption isotherm of lactic acid is shown. Unmodified Si02 does not have remarkable adsorption in aqueous solution under these circumstances. The result shows the effect of the amino modification quite clearly, because the lactic acid load of the adsorbent is remarkable, and it is difficult to adsorb small water-soluble molecules in an aqueous environment. 

Figure 7. Adsorption isotherm of lactic acid on an amino-modified adsorbent The composition was 5/95 (weight percent) in NH2(CH2)3Si03/2/Si02. The mole surface was found to be 9.8 X 10 5 -Nfa/g the method was that of reference 17. The BET surface area was 350 m2/g the hatched area indicates high loads even at low equilibrium concentrations.

Fig. 7 6. Adsorption of color from crude lactic acid...

Messai I, Delair T (2005). Adsorption of chitosan onto poly(D,L-lactic acid) particles A physico-chemical investigation. Macromolecular Chem. Phys. 206 1665-1674. 

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