Using Phosphonium Based Ionic Liquid for Recovery of Acetic Acid by Reactive Extraction

METE H., Aşçı Y. S.

ICECCE 2018 : 20th International Conference on Environmental Chemistry and Chemical Engineering, Roma, Italy, 17 September 2018, vol.20, no.9, pp.966

  • Publication Type: Conference Paper / Summary Text
  • Volume: 20
  • City: Roma
  • Country: Italy
  • Page Numbers: pp.966
  • Yıldız Technical University Affiliated: Yes


Abstract[U1] — Carboxylic acids (R-COOH) are the best known of the organic acids. From the past to the present, there has been a considerable amount of space in the chemical industry.

Carboxylic acids are naturally produced in the fermentation process, at the carboxylic acids are obtained as dilute aqueous solutions. Aqueous solutions are generally obtained in the form of carboxylic acid concentrations of 10% or less by weight. This makes it necessary to recovery of acids at the end of the process.

In literature, for recovering carboxylic acids from diluted wastewater and fermentation media, reactive extraction method has been applied with classical organic solvents (toluene, decanol, etc).

In the scope of the study, extraction was carried out on the acetic acid (CH3COOH) with a wide range of applications, medicine and chemical industry.

 First purpose of study, is to prevent the disposal of carboxylic acids as waste and therefore is to develop an effective recovery method.

In literature, for recovering these acids from diluted wastewater and fermentation media, reactive extraction method has been applied with classical organic solvents (toluene, decanol, etc). Organic solvents, is preferred frequently, including additional environmental hazards.  Common ionic liquids (IL’s) consist of organic cations (mostly nitrogen or phosphorus containing) and organic or inorganic anions. Despite the toxic effects of commonly used and conventional solvents, ionic liquids are being explored extensively as available alternative "green" solvents.

 Secondly purpose of study; a more effectively and more environmentally friendly approach was taken to remove acetic acid from the resulting aqueous medium by fermentation.

 For this purpose, as a phosphonium based ionic liquid, 1-Butyl-3-methylimidazolium hexafluorophosphate [BMIM-PF6] was used and tested against other solvents such as methyl isobutyl ketone (MIBK), 1-decanol, toluene, cyclohexyl acetate (CHA) and dimethyl phthalate (DMP) which frequently serve in the literature.

 In the applied reactive extraction method, tri-n-octylphosphine oxide (TOPO), which is a good complexing agent from the group of alkyl phosphine oxides and tripropylamine (TPA) from the tertiary amine group, was used as the reactant.

 Acetic acid in an aqueous solution of 10% (g/ml) by weight was prepared for this study as obtained by fermentation broth.

 In the presence of TPA (tripropylamine) as a reactive agent, when an ionic liquid is selected as the solvent, better results yielded than the experiments with other solvents. The water phase acid concentration decreased by 0.15% (g/g). 98.4 % separation efficiency was calculated.

 In the presence of TOPO (tri-n-octylphosphine oxide), acetic acid aqueous solution prepared by 10% (g/ml). When an ionic liquid is selected, water phase acid concentration decreased by 3.35%. The activity value is calculated as 65%.

 In the light of the findings, has been observed that the TPA-IL relationship, which is environmentally more efficient and has a separation efficiency of about 100%, will contribute positively to the literature and industrial applications.

But in terms of environmental benefit, TOPO and ionic liquids will be more advantageous compared to the presence TPA-IL. If the 

separation factor is retained in the second plan, results obtained with TOPO will not be underestimated.

 Experimental research can be sustained for the most environmentally and the most efficient separation.

Keywords— Acetic acid, carboxylic acid, fermentation broth, ionic liquid, reactive extraction, tri-n-octylphosphine oxide (TOPO), tripropylamine (TPA).

H. M. (Author) is with Yıldız Technical University, Istanbul, She is now with the department of Chemical Engineering, 34220 TR (phone: +90 212 383 47 51); (e-mail:

Y. S. A., is with Istanbul University, Istanbul, 34320 TR (phone: +90 212 473 70 70 – 17997); (e-mail:

 [U1]Abstract cannot contain less than 500 characters and more than 500 words. Please revise the abstract and follow the guidelines below to what your abstract should include:

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