Abstract
Lactic acid, an important commodity chemical for various applications, is mainly produced through fermentation. In this study, the potential of non-ionic surfactants (an alcohol ethoxylate (AE) and two alcohol alkoxylates (AAs)) as solvents for the extraction of lactic acid from aqueous solutions is reported for the first time. Ternary mixtures containing lactic acid, water, and surfactants were prepared for the assessment. The results indicated that for all the systems, the water–surfactant binary pair exhibits partial immiscibility. Furthermore, the results suggested that with respect to the size of the two-phase region and stability of phases developed, the AE is the suitable solvent for the targeted extraction process. Thus, tie-lines for the system lactic acid + water + AE were then determined to establish the phase diagram of the system at 308.15 K. From the tie-lines, distribution coefficients and separation factors were estimated, which indicated that a compromise between the size and number of extraction units is necessary if AE is to be used as a solvent for lactic acid extraction. The extraction efficiency was estimated to be only about 37–48%. Nevertheless, the biodegradability and non-toxicity of AE makes it a viable solvent for the development of the extractive lactic acid fermentation process.
Highlights
Lactic acid is a compound with a unique characteristic of having both hydroxyl and carboxylic acid groups, making it a commonly used precursor for wide ranging applications in the cosmetic, pharmaceutical, polymer, textile, food, and chemical industries
The results indicated that all the systems studied belong to the Type 1 Treybal classification of ternary systems [35], with the water–surfactant binary pair exhibiting partial immiscibility
Compared to other solvents that have been evaluated for the the targeted extraction process, non-ionic surfactants
Summary
Lactic acid is a compound with a unique characteristic of having both hydroxyl and carboxylic acid groups, making it a commonly used precursor for wide ranging applications in the cosmetic, pharmaceutical, polymer, textile, food, and chemical industries. To improve lactic acid productivity, genetic and metabolic engineering [11,12,13,14], fed-batch fermentation mode [15,16], and continuous fermentation [17] can be exploited Among these options, the continuous fermentation offers the possibility of applying an extractive fermentation strategy to remove or recover the lactic acid as it is produced during the process thereby eliminating the pH-induced microbial inhibition [1]. The ternary phase diagram for lactic acid + water + non-ionic surfactant was established at 308.15 K (the commonly used temperature for mesophilic lactic acid fermentation) This was done to determine the extraction effectiveness of the surfactant as indicated by the distribution coefficients and separation factors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
