Reactive Extraction of Monocarboxylic Acids (Formic, Acetic, and Propionic) Using Tributyl Phosphate in Green Solvents (Cyclopentyl Methyl Ether and 2-Methyltetrahydrofuran)

Abstract

The separation of monocarboxylic acids (formic, acetic, and propionic) from aqueous solutions is still a current issue for both scientific and industrial fields. Reactive extraction with an adequate extractant and diluent system has been focused and researched as an alternative to other separation techniques. Lately, the use of green solvents instead of conventional organic solvents in carboxylic acid extraction has received a great amount of attention. In this aspect, in the present research, the recovery of formic acid (FA), acetic acid (AA), and propionic acid (PA) from aqueous solutions was carried out by reactive extraction with green solvents. In the current reactive study, tributyl phosphate (TBP) has been used as an extractant, and green solvents, cyclopentyl methyl ether (CPME) and 2-methyl­tetra­hydro­furan (2-MeTHF), have been utilized as diluents. The effect of TBP concentration (0.7–5.2 mol·kg–1) on the extraction power was investigated. In addition, the effects of the use of two different green solvents on extraction were also investigated. Distribution coefficient (D), extraction efficiency (E%), and loading factor (Z) values were ascertained and interpreted. D, E, and Z were determined to be in the ranges of 0.289–4.003, 22.41–78.41%, and 0.198–2.218, respectively. It was also observed that, for the studied range, the extractant concentration was increased to be effective when using CPME as the diluent, but a similar effect was not seen when 2-MeTHF was used. However, 2-MeTHF was observed to be a more effective solvent for physical extraction. The extraction efficiency in both diluents increased in the order of PA > AA ≥ FA.

Appraisal of the capacity of natural oils for partitioning of itaconic acid via reactive extraction

“…The Ɗ and η % values are affected by the type of diluent and extractant concentration 20 . TBP affects interactions through complexation with molecules and self‐association with diluents and solvents 21 . It contains a phosphoryl group that functions as an electron acceptor and donor 22,23 .…”

P-Chloride-Free Synthesis of Phosphoric Esters: Microwave-Assisted Esterification of Alkyl- and Dialkyl Phosphoric Ester-Acids Obtained from Phosphorus Pentoxide

“…It is recalled that trialkylphosphates are widely used alkylating agents that may be applied as solvents and extractants for a series of metal ions from wastes and organic acids from aqueous solutions. [39][40][41][42] The novel P-chloride-free, two-step synthetic procedure elaborated is suitable for the conversion of mixtures of the corresponding monoalkylphosphate (1a-d) and dialkylphosphate (2a-d), obtained from P 2 O 5 and ROH, into the appropriate trialkylphosphates (3a-d). The first step is a MW-assisted, ionic liquid-catalyzed, selective direct esterification of monoalkyl esters 1a-d with primary alcohols at 175-220 °C, leading to the dialkyl species 2a-d.…”

“…It is recalled that trialkylphosphates are widely used alkylating agents that may be applied as solvents and extractants for a series of metal ions from wastes and organic acids from aqueous solutions. 39 40 41 42…”

“…Our model involved the conversion of phosphoric esteracids E and F into triesters G/H, with identical alkyl groups that are often used as alkylating agents, solvents and extractants, even on a larger scale. Either metal ions, such as lithium, bismuth, copper, rhenium, molybdenum, gold, as well as actinides and lanthanides, 39,40 or even carboxylic acids 41,42 may be recovered from wastes.…”

Biobased 2,5-Dimethyltetrahydrofuran as a Green Aprotic Ether Solvent

“…It is very important to separate and purify these monocarboxylic acids from the wastewater stream. 28 The recovery efficiency of monocarboxylic acid by 2,5-DMTHF, 2-MeTHF, and CPME extraction was tested with the initial 10% acid concentrations in the aqueous solution, and the results are shown in Table 7. Research shows that the recovery efficiency of 2,5-DMTHF for formic acid, acetic acid, and propionic acid is slightly less than that of 2-MeTHF but much higher than that of CPME.…”