Recovery process of lactic acid using two distillation columns

  • Joung Yeon Kim
  • Yo Jin Kim
  • Won Hi Hong
  • Günter Wozny
Article

DOI: 10.1007/BF02936594

Cite this article as:
Kim, J.Y., Kim, Y.J., Hong, W.H. et al. Biotechnol. Bioprocess Eng. (2000) 5: 196. doi:10.1007/BF02936594

Abstract

Lactic acid is of interest as the raw materials of polylactide that is a biodegradable polymer. For an effective purification of lactic acid, batch distillation with the simultaneous reactions was used. Two Oldershaw columns and reboilers were used for fractionation of methanol and reactions. Esterification reaction of lactic acid with methanol produced methyl lactate and water. The products of the esterification reaction, methyl lactate and water were transported to the reboiler of the hydrolysis part. In hydrolysis part, reaction of methyl lactate and water reproduced lactic acid and methanol. Methanol produced in the hydrolysis part and unreacted methanol in the esterification part were separated by distillation and recycled to the reboiler of the esterification part so that the esterification reaction would be stimulated. Thus, pure lactic acid solution remained in the reboiler of the hydrolysis part. The effect of the number of stages in column on the recovery yield was also investigated. In the operation with columns the recovery yield of lactic acid was improved. It is due to the fact that the columns improved the fractionation of components and stimulated the reactions in two parts.

Keywords

lactic acid reactive batch distillation esterification hydrolysis 

Nomenclature

Ci

Concentration of each component [mol/g]

Cc

Concentration of catalyst [g-cat./g-sol.]

E

Activity energy [J/mol]

HB

Holdup of reboiler [g]

k

Reaction constant

K

Reaction equilibrium constant

LB

Flow rate of the stream transported from the esterification part to the hydrolysis part [mol/sec]

R

Reaction rate [mol/g sec]

S

Flow rate of the recycle stream from the top of the esterification part or the hydrolysis part [mol/sec]

t

Time [sec]

Subscripts

i

Index of components

Est

Esterification reaction part

Hyd

Hydrolysis reaction part

Copyright information

© The Korean Society for Biotechnology and Bioengineering 2000

Authors and Affiliations

  • Joung Yeon Kim
    • 1
  • Yo Jin Kim
    • 1
  • Won Hi Hong
    • 1
  • Günter Wozny
    • 2
  1. 1.Department of Chemical EngineeringKorea Advanced Institute of Science and TechnologyTaejonKorea
  2. 2.Institut für Prozeß-und AnlagentechnikTechnische Universität BerlinBerlinGermany

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