US EPA

1449180 

Journal Article 

Recovery of alkyl lactate from ammonium lactate by an advanced precipitation process 

Kwak, H; Hwang, DWon; Hwang, YKyu; Chang, JSan 

2012 

1 

Separation and Purification Technology
ISSN: 1383-5866 

93 

25-32 

10.1016/j.seppur.2012.03.025 

WOS:000305262400004 

The recovery of lactic acid from ammonium lactate solution
is impossible by the conventional acidification process because of the high solubility and lack
of precipitation of ammonium sulfate. We found that only the addition of methanol to the solution
during acidification of ammonium lactate was very effective in decreasing the solubility of the
produced ammonium sulfate. This product could then be separated from the solution by simple
filtration. With this advanced acidification process, the lactic acid filtrate was transformed
into methyl lactate rapidly by an esterification reaction with methanol even at room temperature.
The methyl lactate produced from the fermentation broth of ammonium lactate by this technique
could be separated by simple distillation without change in the optical purity of lactic acid.
This approach is simple and cost effective because all processes can be carried out at room
temperature without complicated equipment. It is also regenerative because the ammonium sulfate
byproduct can be utilized for production of sulfuric acid and ammonia. Crown Copyright (C) 2012
Published by Elsevier B.V. All rights reserved. 

Ammonium lactate; Lactic acid; Fermentation; Separation; Alkyl lactate