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Owing to its chemical and pharmacological significances, the efficacy of reactive separation of protocatechuic acid (0.001–0.01 kmol m⁻³) from aqueous stream by means of tri-n-octylamine (TOA), di-2-ethylhexyl phosphoric acid (D2EHPA) as well as tri-n-butyl phosphate (TBP) in octanol has been investigated, in terms of extraction efficiency, loading...
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The debate on whether the nonlinear sorption of nonionic organic compounds (NOCs) by soil organic matter (SOM) is captured by nonlinear partition or adsorption has been going on for decades because the used SOM samples are complex mixtures from various precursors with varied humification degrees in natural environment. Therefore, in this study, hyd...
Citations
... The modified Kremser equation [27][28][29] with extraction factor E x was employed to estimate the number of theoretical stages (NTS) for a countercurrent extraction process. ...
BACKGROUND
Owing to the continuous growth of petroleum prices over the last few decades, there has been a renaissance in interest in the large‐scale manufacturing of platform chemicals via the fermentation route. The present work emphasizes the extraction of itaconic acid from an aqueous solution by dissolving reactive tri‐n‐butyl phosphate (TBP) in natural, non‐toxic diluents such as sunflower oil, rice bran oil, and sesame oil.
RESULTS
The experimental results were explained in terms of distribution coefficient (Ɗ), extraction efficiency (η%), equilibrium complexation constant (Ke), and loading ratio (ϕ). At the highest concentration of itaconic acid 0.250 mol L⁻¹ and TBP 1.099 mol L⁻¹, the maximum extraction efficiency and distribution coefficient for sunflower oil were obtained, at 88.72% and 7.94%, respectively. The diffusivity (DIA−S) of itaconic acid towards the interface of organic and aqueous phases was obtained as 1.11 × 10⁻⁶ cm² s⁻¹ with the Wilke–Chang equation and 4.40 × 10⁻⁷ cm² s⁻¹ using the Reddy–Doraiswamy relation. The lowest value of solvent‐to‐feed (S/F) proportion was estimated as 6.66, with the minimum number of stages required for counter‐current extraction being ~4.
CONCLUSION
In reactive extraction of itaconic acid with TBP, the highest extraction efficiency and distribution coefficient was attained with sunflower oil, followed by rice bran oil and sesame oil. Higher concentrations of itaconic acid (0.250 mol L⁻¹) and TBP (1.099 mol L⁻¹) are suitable combinations for all the natural diluents. Diffusivity values revealed the extent of diffusion of itaconic acid in the solvent phase and strongly depended on the density and viscosity of the solvent. The experimental results could be utilized to design a continuous extraction column. © 2023 Society of Chemical Industry.
... Maximum extraction efficiency for physical extraction of PCA using different diluents is summarised in Fig. 4 [90][91][92][93][94][95][96][97]. The stoichiometry of the acid-extractant complexes, the loading of the extractants, and the development of the third phase are all affected by the diluents' characteristics [100]. ...
... Higher distribution coefficient (K D ) values are produced by the alcohol octanol, a protic diluent with a hydrogen atom bound to an oxygen atom that is electronegative and capable of creating a hydrogen bond. For physical extraction studies the maximum extraction efficiency, E% obtained was 68.9% and distribution coefficient, K D (which is the ratio of the acid concentration in the aqueous phase to the total organic phase acid concentration at equilibrium) is 2.22 with octanol [95]. Even though natural oils exhibited lower extraction for PCA extraction trials when compared to conventional diluents, they are still valuable when taking toxicity into account. ...
... It was found that the extraction efficiency improved when extractant and diluent were employed together as opposed to diluent alone. The highest K D value recorded was 7.80 with tributyl phosphate (TBP), 10.36 with trioctyl amine (TOA), and 6.36 with di-2-ethyl hexyl phosphoric acid (D2EHPA) using diluent octanol [95]. The concentration of the extractant was set between 10 and 50% by volume, a greater extractant concentration was constrained in light of numerous reasons like an increase in overall cost of the process because of the price of the extractants, toxicity to the microorganisms in fermentation broth at greater extractant concentrations, and back-extraction. ...
In the current scenario, where environmental degradation, global climate change, and the depletion of petroleum feedstock pose significant challenges, the chemical industry seeks sustainable alternatives for manufacturing chemicals, fuels, and bioplastics. Biorefining processes that integrate biomass conversion and microbial fermentation have emerged as preferred approaches to create value-added compounds. However, commercializing biorefinery products is hindered by dilute concentrations of final products and the demand for high purity goods. To address these challenges, effective separation and recovery procedures are essential to minimize costs and equipment size. This article proposes a biorefinery route for the production of protocatechuic acid (PCA) by focusing on in situ PCA separation and purification from fermentation broth. PCA is a significant phenolic molecule with numerous applications in the pharmaceutical sector for its anti-inflammatory, antiapoptotic, and antioxidant properties, as well as in the food, polymer, and other chemical industries. The chemical approach is predominantly used to produce PCA due to the cost-prohibitive nature of natural extraction techniques. Reactive extraction, a promising technique known for its enhanced extraction efficiency, is identified as a viable strategy for recovering carboxylic acids compared to conventional methods. The extraction of PCA has been explored using various solvents, including natural and conventional solvents, such as aminic and organophosphorous extractants, as well as the potential utilization of ionic liquids as green solvents. Additionally, back extraction techniques like temperature swing and diluent composition swing can be employed for reactive extraction product recovery, facilitating the regeneration of the extractant from the organic phase. By addressing the challenges associated with PCA production and usage, particularly through reactive extraction, this proposed biorefinery route aims to contribute to a more sustainable and environmentally friendly chemical industry. The incorporation of PCA in the biorefinery process allows for the utilization of this valuable compound with diverse industrial applications, thus providing an additional incentive for the development and optimization of efficient separation techniques.
... The diluent octanol was chosen based on previous studies conducted. 35 In the case of physical extraction by use of diluents alone, the major factor affecting carboxylic acid removal appears to be equilibrium solubility and solvation by donor bonds. The importance of solvation in carboxylic acid extraction is emphasised by the discrepancy of distribution ratio for the same acid in different diluents. ...
BACKGROUND
The production of protocatechuic acid (PCA) (which has significant applications in organic intermediates, chemical reagents, pharmaceuticals, dye synthesis, etc.) by fermentation is a potential replacement to the conventional petrochemical routes of carboxylic acid production. However, the extraction processes of these carboxylic acids from fermentation broths and dilute waste water using organic solvents imply additional environment hazards. Ionic liquids (ILs) have come to the focus because of their superior properties as well as environmentally friendly nature, and are being intensively used for separation processes. The equilibrium extraction efficiency for bio PCA using two imidazolium ILs – 1‐butyl‐3‐methylimidazolium tetrafluoroborate (bmimBF4) and 1‐butyl‐3‐methylimidazolium hexafluorophosphate (bmim‐PF6) – was investigated under isothermal conditions in diluent octanol. The distribution coefficient and extraction efficiency were determined to be much greater than those obtained with traditional extractants and diluents.
RESULTS
This work is the first of its type to use ILs for PCA isolation. From the equilibrium extraction experiments conducted it was observed, in octanol, that the average distribution coefficients (KD) values for bmimBF4 and bmim‐PF6 were 5.3 and 5.36, respectively, with average extraction efficiencies of 83.84% and 84.08% at a lower IL concentration of 10% by volume, and the findings may be utilised to develop an extraction purification system for PCA separation from aqueous streams. Multiple stages of separation may lead to almost 100% recovery.
CONCLUSION
PCA was efficiently extracted from aqueous solutions using bmimBF4 and bmim‐PF6 in octanol, providing preliminary practical information and theoretical support for PCA separation, purification and recovery. © 2022 Society of Chemical Industry (SCI).
... LLE has been proven with many advantages over other methods [2]. Recovery of various value-added acids like lactic acid, [3][4][5][6][7] acrylic acid, [8,9] nicotinic acid, [10,11] itaconic acid, [12] levulinic acid, [13][14][15] tartaric acid, [16] caproic acid, [17,18] gallic acid, [19,20], protocatechuic acid, [21][22][23][24] propionic acid, [25][26][27][28][29] vanillic acid, [30] etc. by extraction method have using several extractants. The extractants are categorized as; (a) Active extractants, (b) Inert extractants, (c) Natural extractants. ...
Glutaric acid finds major application in corrosion inhibitors, anti-scaling agents, pharmaceutical synthesis, etc. mainly as a polymer building block. However, production of glutaric acid is quite difficulty, necessitated research into viable options for glutaric acid recovery. The liquid-liquid extraction method has been employed to recover glutaric acid from aqueous phase using a variety of inert extractant (cyclohexane) and natural, non-toxic extractants (rice bran and sesame oil). The extraction efficiency (%E) and distribution coefficient (KD) were calculated based on equilibrium data obtained at 298.15±1 K. The trend observed for the average distribution coefficient along with extraction efficiency respectively are as follows: rice bran oil (0.152, 12.48%) > Cyclohexane (0.075, 6.90%) > Sesame oil (0.037, 3.53%). The rice bran oil has the highest extraction efficiency, whereas sesame oil provided the lowest extraction efficiency.
... Adsorption faces the demerit associated with the cost of regeneration of commercial adsorbents, and ultrafiltration process suffers from problems like membrane fouling. Recently, there are studies done on the reactive extraction of protocatechuic acid using extractants TOA, D2EHPA, and TBP in natural oils and conventional solvents (Antony et al., 2018, Antony et al.,2018a, Antony et al.,2018bDe et al. 2018aDe et al. , b, 2019. ...
... For PCA based on literature studies, the concentration of acid was chosen between 1 and 10 mmol L −1 (Antony et al. 2018a). Equilibrium studies were conducted for 5 h at isothermal conditions of 298 K, and analysis was done by UV-visible spectrophotometer (Antony et al., 2018). Parameters like distribution coefficient values (K D ), which is the ratio of acid concentration in the aqueous and organic phases, and extraction efficiency (E%), which is the ratio of concentration of PCA in the extracted phase to the initial concentration of PCA, were found out for the different categories of diluents in PCA, and the results are summarised in Table 1. ...
... Distribution coefficient represents the selectivity of the solvent for the product, compared with water. Among the diluents used, it was observed that octanol gave the highest extraction efficiency of 68.95% and K D 2.22 for PCA concentration 0.01 mol L −1 and temperature of 298 K (Antony et al., 2018). Octanol is a protic solvent and a hydrogen-bond donor; it has H atoms bounded to O-which is electronegative element. ...
3,4-Dihydroxybenzoic acid, commonly known as protocatechuic acid, is a naturally occurring phenolic compound, being the active component of many medicinal and edible plants. The in vitro and in vivo studies of protocatechuic acid conclude that it possesses many pharmacological properties. Protocatechuic acid, present in waste streams of food processing industries, is considered a phenolic pollutant. Owing to its bactericidal properties and in order to maintain the standards of disposal, its removal from the waste streams is necessary. Protocatechuic acid finds applications also in bioplastics, polymers, and also bio-based active films to improve food preservation. Its direct extraction from plant secondary metabolites possesses many difficulties. Recently reports of protocatechuic acid production by several Bacillus species are present in literature. For the retrieval/removal of protocatechuic acid from aqueous streams, methods like adsorption, O3/UV or H2O2/UV, and microbial degradation are in practice. For the retrieval of carboxylic acid from fermentation broths and aqueous streams, reactive extraction by the use of specific extractants has been found to be a most suitable method owing to its several advantages. The present paper is focused on the separation of protocatechuic acid by reactive extraction as a promising approach. The parameters needed for the design such as distribution coefficient, water co-extraction, physical and chemical extraction, effect of initial acid concentration, diluents, extractant, and extractant concentration have been discussed.
... Some literature is availabile on the equilibrium studies on the reactive separation of PCA [34,35,36,37,38]. Apart from reactive extraction, for the retrieval of PCA from the aqueous waste stream of food processing industries, the methods in practice till date includes microbial degradation [39], ultrafiltration [40], adsorption [41], H 2 O 2 /UV or O 3 /UV [42], etc., each of the methods facing its own merits as well as certain limitations. ...
... The K D values for the temperature ranges 288-313 K along with the dimerization (D) and partition (P) coefficients values are given in Table S2. Antony et al. [36] did studies at 298 K in octanol. PCA-octanol solvation occurs through hydrogen bonding (O⋯H) amongst O atom from -OH group of octanol and H atom from -COOH group of PCA. ...
Owing to its biological and chemical applications, the separation of protocatechuic acid, a polyphenol compound, is of interest to researchers. Extraction studies with initial acid concentration (0.001–0.01 kmol m⁻³) using aminic extractant tri-n-octyl amine (TOA) (0.2287 kmol m⁻³ -1.1436 kmol m⁻³) in diluent octanol at diverse temperature ranges from 288 K - 313 K was done. Parameters like loading ratio, distribution coefficient, equilibrium complexation constant, diffusion coefficient, number of stages necessary for protocatechuic acid counter-current extraction were obtained; this information is useful in designing a process for the in situ separation of the acid from the fermentation broth as well as from the waste streams. The increase in temperature distribution coefficient was found to increase up to the temperature of 303 K and was found to decrease with a further rise in temperature. The entropy and enthalpy values for the reaction at different temperatures were obtained. The highest extraction of 91.1 % and distribution coefficient of 1.14 were obtained at 313 K for an acid concentration of 0.01 kmol m−3, and TOA concentration of 1.1436 kmol m⁻³ and 4 stages are required for counter-current extraction process for acquiring the required separation efficiency. Development of 1:1 complex of protocatechuic acid and TOA take place as concluded from the values of the loading ratio.
Due to superior characteristics, ionic liquids (IL) have become a more environmentally friendly alternative to traditional toxic, flammable, and volatile organic solvents. Protocatechuic acid (PCA) is a widely distributed phenolic acid and a key metabolite of complex polyphenols. It is a molecule that functions as a chemical building block for polymers and plastics as well as has pharmacological effects. The current project’s goal is to enhance the recovery of PCA by IL-based extraction from industrial waste streams and fermentation. This research investigates the separation of PCA from an aqueous stream using Imidazolium-based IL, 1-butyl-3-methylimidazolium octyl sulfate and 1-Hexyl-3-methylimidazolium hexafluorophosphate with an efficiency of about 87% at 10% IL concentration for a PCA concentration of 10 mmol L⁻¹. The influence of the initial PCA concentration and IL concentration on the separation efficiency was also investigated, and various parameters helpful for the design of an industrial separation unit were determined.
Electrochemical conversion of biomass to value‐added chemicals has gained impetus in recent years. Herein, we present a methodology for recovering biomass‐derived 2‐furoic acid from the dilute aqueous stream by reactive extraction. The reactive extraction was performed using a chemical extractant, trioctylamine (TOA), with diluents (octanol, chloroform, diethyl ether). Equilibrium parameters influencing the recovery of 2‐furoic acid were evaluated. Using TOA in various diluents, the 2‐furoic acid was recovered with 85 ‐ 99% efficiency. A 1:1 complex of the 2‐furoic acid – TOA was formed in the organic phase, and the experimental equilibrium complexation constant was compared with that obtained from the relative basicity and Langmuir models. The equilibrium parameters were used for column design to estimate the solvent to feed ratio (S/F) and the number of theoretical stages (NTS). The NTS required is 12 to attain 99% recovery of 2‐furoic acid in counter‐current extraction. The present study sheds light on the reactive extraction process adopted for process intensification with electrochemical conversion, paving the way for the commercialization of valuable products obtained from biomass. This article is protected by copyright. All rights reserved.
