Abstract
Lactic acid can be derived from microbial fermentation and be used as a
platform chemical in various industrial applications. This study aims to
investigate the challenges involved in combining a low-cost,
heterogeneous feedstock, such as a mixture of candy-waste and digestate,
with an optimized downstream strategy to achieve maximum recovery of
high-purity lactic acid, targeting low energy consumption. To achieve
this goal, four membrane separation technologies, namely
microfiltration, nanofiltration, monopolar, and bipolar electrodialysis,
were combined to design two purification processes. Microfiltration
served as the pre-purification step, followed by either process A, which
combined nanofiltration and bipolar electrodialysis, or process B, a
combination of monopolar and bipolar electrodialysis. The findings
emphasized the importance of pH as a control factor. Nanofiltration at
pH 2.8 and monopolar electrodialysis at pH 4.0 led to increased lactic
acid recovery. Moreover, it was observed that process B resulted in
1.09-fold higher lactic acid recovery than process A. However, process A
had a 1.19-fold lower specific energy consumption, and the presence of
ions in the final solution was reduced by 5-fold. In both processes
lactic acid was separated from sugars and organic acids. Overall, the
findings of this study suggest that membrane separation technology is a
viable method for separating lactic acid produced from a mixture of
residual candy-waste and digestate.
Original language | English |
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Article number | 110881 |
Journal | Journal of Environmental Chemical Engineering |
Volume | 11 |
Issue number | 5 |
Number of pages | 10 |
ISSN | 2213-2929 |
DOIs | |
Publication status | Published - 2023 |
Keywords
- Electrodialysis
- Lactic acid
- Microfiltration
- Nanofiltration
- Organic waste