Reactive Extraction Of Lactic Acid Research Articles

Mineral Acid Co-Extraction in Reactive Extraction of Lactic Acid Using a Thymol-Menthol Deep Eutectic Solvent as a Green Modifier.

Carboxylic acids can be isolated from fermentation broths using reactive liquid-liquid extraction, offering an alternative to the environmentally harmful state-of-the-art process of precipitating calcium lactate. To enhance the sustainability of liquid-liquid extraction processes, greener solvents, such as natural deep eutectic solvents, are investigated. However, fermentation broths often exhibit pH values unsuitable for carboxylic acid extraction, which can be adjusted using mineral acids, though mineral acids may be co-extracted. In this study, we systematically examine the co-extraction of hydrochloric, nitric, sulfuric, and phosphoric acid during extraction and back-extraction of lactic acid. The solvent phase consisted of tri-n-octylamine, trioctylphosphine oxide, or tributyl phosphate diluted in a thymol-menthol deep eutectic solvent. The back-extraction was conducted using a diluent swing with p-cymene as the antisolvent and water as the receiving phase. Tri-n-octylamine showed the highest efficiency for lactic acid (up to 29.8%) but also the highest co-extraction of mineral acids (up to 50.9%). In contrast, trioctylphosphine oxide exhibited a lower but more selective lactic acid extraction (5.94%) with low mineral acids co-extraction (0.135%). Overall, the highest co-extraction was observed for phosphoric acid and the lowest for nitric acid. In conclusion, the selected solvent phase composition and mineral acid influence the co-extraction and, thus, final product purity. The successful application of the natural deep eutectic solvent as the modifier enhances the sustainability of liquid-liquid extraction processes.

Reactive Extraction of Lactic Acid Using Trioctylamine with Environmentally Friendly Solvents

In this study, the separation of lactic acid from aqueous solutions using trioctylamine (TOA) reactant and environmentally friendly solvents such as sunflower and rice bran oil was investigated, and it was aimed to contribute to the separation of lactic acid by reactive extraction. It is aimed to determine the most suitable reactant / solvent ratios with reactive extraction analyzes. As a result of the studies, the highest efficiency (72,91%) was achieved with the TOA reactant. An increase in yield occurred as a result of using both sunflower oil and rice bran oil (1:1) together. According to the results of the research, it was determined that the addition of TOA to the organic phase increases the extraction efficiency in the recovery of carboxylic acids from aqueous solutions. While the physical extraction yield was 11.85%, the yield increased up to 72,91% in reactive extraction. An increase in yield was observed about 7 times. As a result of the data obtained, it was understood that with the increase in the extractant concentration, the dispersion coefficient (from 0,13 to 2,69) increased, and the loading factor (from 1,79 to 0,69) values decreased. When the organic phase mixtures formed with the extractant and diluent combinations were examined, it was determined that the best results in terms of extraction efficiency were obtained when 3,62 M TOA for lactic acid was used.

Reactive extraction of lactic acid from sweet sorghum silage press juice

• Uncontrolled fermentation broths from biorefineries can be used as lactic acid source. • Reactive extraction is applicable for lactic acid isolation from complex mixtures. • An extraction efficiency of up to 41.1% is reached with amine-based ion exchangers. • Back-extraction efficiency reaches up to 98.2% for 0.3 M NaOH or 0.3 M NaHCO 3. • Crud formation can be reduced to 2.6 vol% by varying the solvent phase composition. Fermentation of residues or side streams can be used to produce valuable products, such as carboxylic acids. Reactive solvent extraction is widely studied as isolation method for lactic acid from fermentation broths. Here, we investigate the reactive extraction of lactic acid from sweet sorghum silage press juice using different extractants, modifiers, and diluents. Besides a high extraction efficiency, a low crud formation with this highly complex raw material is targeted. Depending on the solvent phase composition, an extraction efficiency of up to 41.1 % was reached using DOA/ALIQ:1–octanol: n –nonane. The crud layer was highly influenced by the applied diluent and amounted to 2.6–42.3 vol% of the total mixture volume. The back-extraction experiments showed, that up to 98.2 % of lactic acid were recovered. Summarizing, the results show that reactive solvent extraction of lactic acid is applicable to highly complex process streams, and crud formation can be reduced by adjusting the solvent phase composition.

Statistical Optimization of Lactic Acid Extraction Using Green Solvent and Mixed Extractants (TOA and TOMAC)

Since some previous years, reactive extraction has become more attractive and competitive technique for the separation and purification of lower carboxylic acids from fermentation broth as well as from dilute aqueous streams. This paper shows the results of investigation of reactive extraction of lactic acid (LA) from an aqueous solution using the synergistic mixture of the extractants (TOA (tri-n-octylamine) and TOMAC (Tri-n-octylmethylammonium chloride)) and a non-toxic and biocompatible green solvent (soybean oil). Three-level Box-Behnken design (BBD) under response surface methodology (RSM) was opted for the experimental design and to interpret the mutual effect of seven independent process parameters on the LA distribution coefficient (KD). The maximum values of LA distribution coefficient (KD=2.51) and its extraction efficiency (ηη=71.5%) were obtained for the optimum values of various process parameters such as 0.02 [M] initial LA concentration (CC1), 0.5 (v/v) extractant ratio (α), 28.66% (v/v) mixed extractants concentration (ψ), 2 (v/v) phase ratio (φ), 270C temperature (T), 102 rpm stirring speed (ω), and 63 mincontact time (τ). This present investigation will provide a noble discussion on LA reactive extraction using green solvent and on various influencing process parameters for gaining the enhanced value of LA distribution coefficient (KD).
 Chemical Engineering Research Bulletin 21(2019) 20-35

Reactive Extraction of Lactic Acid using Environmentally Benign Green Solvents and Synergistic Mixture of Extractants

An environment-friendly reactive extraction method as a novel phase separation technique was postulated to extract lactic acid (LA) from aqueous solution by means of environmentally benign green solvents along with the synergistic mixture of extractants. Reactive extraction of LA has been carried by using synergistic mixture of extractants (trioctylamine (TOA), Aliquat336, and tridodecylamine (TDDA)), organic solvents, and non-toxic and biocompatible green solvents. From the different LA reactive extraction systems investigated, the system having sunflower oil, synergist extractant (TOA and Aliquat336) and Butan-2-ol were found to be the most favourable system. The LA distribution coefficient (KD=27.75±0.22) and extraction efficiency (η=97.17±0.54%) were obtained by a system consisting of LA concentration (0.05 [M]), TOA (15%, v/v), Aliquat336 (15%, v/v), solvent ratio (2.5, v/v), phase ratio (1:1, v/v), agitation speed (100 rpm), and stirring time (120 min). The main driving force for this research work on the LA reactive extraction from aqueous solution was to develop a suitable combination of extractants, organic solvents and natural solvents which possesses high affinity towards LA and also has less toxicity towards LA producing microbes.

Reactive Extraction of Lactic Acid, Formic Acid and Acetic Acid from Aqueous Solutions with Tri-n-octylamine/1-Octanol/n-Undecane

The present work develops the basics for the isolation of lactic acid, acetic acid and formic acid from a single as well as a mixed feed stream, as is present, for example, in fermentation broth for lactic acid production. Modelling of the phase equilibria data is performed using the law of mass action and shows that the acids are extracted according to their pka value, where formic acid is preferably extracted in comparison to lactic and acetic acid. Back-extraction was performed by 1 M NaHCO3 solution and shows the same tendency regarding the pka value. Based on lactic acid, the solvent phase composition, consisting of tri-n-octylamine/1-octanol/n-undecane, was optimized in terms of the distribution coefficient. The data clearly indicate that, compared to physical extraction, mass transfer can be massively enhanced by reactive extraction. With increasing tri-n-octylamine and 1-octanol concentration, the equilibrium constant increases. However, even when mass transfer increases, tri-n-octylamine concentrations above 40 wt%, lead to third phase formation, which needs to be prevented for technical application. The presented data are the basis for the transfer to liquid membrane permeation, which enables the handling of emulsion tending systems.

Parametric optimization of green synergistic reactive extraction of lactic acid using trioctylamine, Aliquat336, and butan-2-ol in sunflower oil by response surface methodology

A novel green synergistic reactive extraction technique for the removal of lactic acid (LA) from aqueous solution was explored. Response surface methodology (RSM) was applied to optimize the process variables for LA synergistic reactive extraction using a mixture of trioctylamine and Aliquat336 as extractants. During this present investigation, 2-butanol and sunflower oil were used as organic and green diluent. Systematic investigation has been carried out to obtain the optimum process conditions viz. initial LA concentration, pH of aqueous solution, extractant ratio, extractant concentration, solvent ratio, phase ratio, temperature, stirring speed, and contact time for maximizing the LA distribution coefficient (KD) and extraction efficiency (%, η). The highest experimentally achievable LA distribution coefficient (KD) and extraction efficiency (%) at optimized process conditions were found to be in close agreement with those predicted by numerical optimization using RSM. Thus, the results of present finding have been shown a great ability of sunflower oil as an economic and environmentally friendly green solvent for LA extraction.

Reactive Extraction of Lactic Acid by Using Tri-n-octylamine: Structure of the Ionic Phase.

Lactic acid is a promising biogenic platform chemical which can be produced by fermentation of cellulose and hemicellulose. However, separating lactic acid from the fermentation broth is extremely costly and technically complex. We therefore investigated whether liquid/liquid extraction of lactic acid with tri-n-octylamine is a cost-effective alternative to the existing downstream processing method. In order to find an answer to this question, the structure of the middle phase of the occurring three-phase region, which is enriched with up to 20 wt. % lactic acid, was explored. The results of our IR, small-angle X-ray scattering and NMR measurements show that this phase is ionic and has a bicontinuous structure. Due to the analogy with bicontinuous microemulsions, it should be possible to further enrich the lactic acid, which could lead to a rethink regarding the design of extraction processes.

A study of parameters affecting the solvent extraction of lactic acid from fermentation broth

Lactic acid has recently been drawing much interest as a raw material for biodegradable polymer. One of the promising technologies for recovery of lactic acid from fermentation broth is reactive liquid-liquid extraction. Equilibrium studies on the reactive extraction of lactic acid with trioctylamine (TOA) in various organic phases and its re-extraction into aqueous solutions were carried out. In this study distribution coeffi- cient, extractability, stripping efficiency of various active and inert diluents with TOA as extractant were investigated, which were higher for active diluents. The effects of operating temperature, speed of agitation, agitation time and diluent composition on extraction efficiency were also studied. Temperature and extraction efficiency were inversely proportional to each other, whereas extraction efficiency was little affected by speed of agitation and agitation time.

Equilibrium Study on Reactive Extraction of Lactic Acid with Tri-n – Butyl Phosphate in n - Hexane

Extraction of carboxylic acids from dilute aqueous solution using traditional solvents such as ketones, alcohols, ethers, and ester is inefficient because the distribution ratio is rather low. Reactive extraction which exploits reversible chemical complexation is an effective separation process for extraction of carboxylic acids from aqueous streams such as fermentation broths and wastewaters. In the extraction process, selection of the solvent is an important aspect to be considered. Considering its solubility in water, cost and availability, tri-n-butyl phosphate (TBP) seems to be an attractive solvent for the extraction of lactic acid from aqueous solution. The purpose of this experiment is to study the equilibrium of the reactive extraction of lactic acid in aqueous solution with TBP in n-hexane. The parameters studied in this experiment were initial concentration of lactic acid in the aqueous phase, TBP concentration in n-hexane phase, and the extraction temperature. The experiments at ambient temperature were carried out using a separatory funnel, while the experiments at other than ambient temperature were carried out using erlenmeyer flask and water bath shaker to adjust the temperature. In this experiment, the initial concentration of lactic acid was varied from 0.1 to 0.5 gmol/dm3. The range of initial TBP concentrations in n-hexane was 0.1 to 1.0 gmol/dm3 and the extraction temperature range was 283 to 313 K. The experimental results showed that the higher the initial concentration of lactic acid in aqueous solution, the higher the distribution ratio for a fixed TBP concentration and extraction temperature. For a fixed initial concentration of lactic acid in aqueous solution and extraction temperature, the distribution ratio of lactic acid is increased by increasing TBP concentration. The overall equilibrium constants (Kpq) for the experiments using TBP concentration ranging from 0.1 to 1.0 gmol/dm3 at the extraction temperature of 293 K are calculated to be 0.0668 to 0.5144. Kpq for the experiments at the temperature ranging from 283 to 313 K at the initial concentration of lactic acid of 0.2 gmol/L are found to be 0.0122 to 0.8856. The Kpq as a function of temperature (T) in K can be expressed as ln Kpq = 10,596/T - 38.08 with sum of square of error of 0.14.

Investigation of liquid–liquid phase equilibria for reactive extraction of lactic acid with organophosphorus solvents

AbstractBACKGROUND: Lactic acid is a versatile commodity chemical with a variety of applications. Synthesis of lactic acid either through fermentation of carbohydrates or through chemical synthesis is state of the art. Separation from dilute aqueous solution is complex and accounts for the major part of production costs. Reactive extraction based on reversible adduct formation is a promising alternative for the separation of lactic acid.RESULTS: Extraction was carried out with the organophosphorus solvents tri‐n‐butyl phosphate, tri‐n‐octylphosphine oxide and Cyanex 923. Shellsol T was used as diluent. Partition coefficients increase with increasing extractant content and decreasing temperature. Cyanex 923 has several advantages compared with tri‐n‐butyl phosphate and tri‐n‐octylphosphine oxide with respect to lactic acid distribution and hydrodynamic properties. Liquid‐liquid phase equilibria for lactic acid extraction with Cyanex 923 were modeled. Selectivity of lactic acid extraction with respect to glycolic acid and formic acid was discussed.CONCLUSION: The organophosphorus extractant Cyanex 923 was found to be an appropriate solvent for lactic acid extraction from aqueous solutions. Experimental data and model data based on the Law of Mass Action showed good agreement. Lactic acid extraction from multi‐acid solution showed good selectivity compared with glycolic acid. Lactic acid selectivity is low with respect to formic acid. © 2012 Society of Chemical Industry

Extraction of lactic acid into sunflower oil and its recovery into an aqueous solution

Demand for lactic acid is growing, especially, for its use in the production of biodegradable polymer (polylactate). The current method of production and separation of lactic acid is both expensive and unsustainable. This is partly due to the cost and lower efficiency of the current method for separating the lactic acid product from the fermentation media. Therefore, the development of alternative technology that will offer efficiency, economic and environmental benefits is of great importance. One of the promising technologies for recovery of lactic acid from fermentation broth is reactive liquid–liquid extraction. In this paper, processes based on reactive extraction of lactic acid into an organic phase and its recovery into an aqueous phase is examined. The percentages of extraction and recovery are determined by using a small pilot-scale microporous hollow-fibre membrane module (HFMM). Firstly, equilibrium experiments were conducted using organic solutions consisting of Aliquat 336 and trioctylamine (as carriers) and tributyl phosphate and sunflower oil (as solvents) The values of the distribution co-efficient (defined as a ratio of the concentration of lactic acid extracted over that remaining in the aqueous solution at equilibrium) were obtained as a function of feed pH (range 4.0–6.5), composition of the organic phase (ratio of carrier to solvent) and temperature (range 8–40°C). The best extraction was obtained with the organic phase of 15wt% tri-octylamine (TOA), 15% aliquat 336 dissolved in 35 wt% tri-butyl phosphate (TBP) and 35% sunflower oil. The percentage extraction from 0.1 M was approx. 70% after 4 h at pH 5.0 and at 35°C at a recirculating flow rate of 15–20 L/h. Lactic acid was reextracted from the organic phase by using 0.5 M sodium carbonate solution and approx. 90% recovery was obtained in 4 h. These results demonstrate that good extraction and recovery of lactic acid in the hollow-fibre membrane are possible. Also because of its potential for application in situ the process would allow to maintain lactic acid concentration at low levels during the fermentation and to improve productivity by suppressing the product inhibition effects.

Equilibria and kinetics for reactive extraction of lactic acid using Alamine 336 in decanol

AbstractLactic acid is an important commercial product and extracting this from aqueous solution is a growing requirement in fermentation‐based industries. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent) system used. The equilibrium complexation constants for ratios of (1:1) and (2:1) have been estimated. The kinetics of extraction of lactic acid by Alamine 336 in decanol has also been determined. The reaction between lactic acid and Alamine 336 in decanol in a stirred cell falls in Regime 3, ie extraction accompanied by a fast chemical reaction occurring in the diffusion film. The reaction has been found to be zero order in Alamine 336 and first order in lactic acid with a rate constant of 0.21 s−1. These data will be useful in the design of extraction processes.© 2002 Society of Chemical Industry

Reactive extraction of lactic acid using alamine 336 in MIBK: equilibria and kinetics

Lactic acid is an important commercial product and extracting it out of aqueous solution is a growing requirement in fermentation based industries and recovery from waste streams. The design of an amine extraction process requires (i) equilibrium and (ii) kinetic data for the acid–amine (solvent) system used. Equilibria for lactic acid extraction by alamine 336 in methyl- iso-butyl-ketone (MIBK) as a diluent have been determined. The extent to which the organic phase (amine +MIBK) may be loaded with lactic acid is expressed as a loading ratio, z=[HL] o/[B] i,o. Calculations based on the stoichiometry of the reactive extraction and the equilibria involved indicated that more lactic acid is transferred to the organic phase than would be expected from the (1:1) stoichiometry of the reaction. The extraction equilibrium was interpreted as a result of consecutive formation of two acid–amine species with stoichiometries of 1:1 and 2:1. Equilibrium complexation constant for (1:1) and (2:1) has been estimated. Kinetics of extraction of lactic acid by alamine 336 in MIBK has also been determined. In a first study of its kind, the theory of extraction accompanied by a chemical reaction has been used to obtain the kinetics of extraction of lactic acid by alamine 336 in MIBK. The reaction between lactic acid and alamine 336 in MIBK in a stirred cell falls in Regime 3, extraction accompanied by a fast chemical reaction occurring in the diffusion film. The reaction has been found to be zero order in alamine 336 and first order in lactic acid with a rate constant of 1.38 s −1. These data will be useful in the design of extraction processes.

In situ reactive extraction of lactic acid from fermentation media

AbstractExtractive lactic acid fermentation was investigated in the presence of sunflower oil and Alamine‐336 (with oleyl alcohol as the diluent solvent). Lactic acid was produced in various media at 37 °C using Lactobacillus delbrueckii (NRRL‐B 445). First, the effects of oleyl alcohol (33.3%, v/v), immobilisation, and immobilisation in the presence of sunflower oil (5, 10, 15%, v/v) on lactic acid production were investigated. It was found that oleyl alcohol did not affect production while addition of sunflower oil increased lactic acid production from 10.22 to 16.46 gdm−3. On the other hand, a toxic effect was observed for oleyl alcohol solutions containing 15–50% (v/v) Alamine‐336. A maximum total lactic acid concentration of 25.59 gdm−3 was obtained when an oleyl alcohol solution containing 15% (v/v) Alamine together with immobilised cells with 15% (v/v) sunflower oil was used. This value was about 2.5 times that obtained from fermentation without organic solutions.© 2001 Society of Chemical Industry

Mass transfer coefficients in reactive extraction of lactic acid from fermentation broths in hollow‐fibre membranes

AbstractMass transfer of lactic acid was investigated during its extractive recovery from fermentation broths in a hydrophobic hollow‐fibre membrane module. The solvent and the aqueous phases were continuously recycled through the hollow‐fibre module into their respective reservoirs, and the mass transfer rate was calculated from the measurements of concentration of lactic acid in solvent phase. Mainly, the tubeside resistance controlled the mass transfer rate. A mathematical analysis was conducted for the mass transfer process in the membrane module and values of the overall mass transfer coefficient were estimated at different flow rates.

Recovery of lactic acid from aqueous model solutions and fermentation broths

The aim of the investigations was to recover lactic acid from fermentation broths in the presence of citric acid and acetic acid. For this purpose the reactive extraction of lactic acid was investigated from model media and fermentation broths with various carrier/modifier/solvent combinations. Experiments were performed using a secondary amine (Hoe F 2562), a tertiary amine (Hostarex A 327) as well as a phosphine oxide as carriers and butylacetate and kerosene as solvents. The effects of the type and concentration of the carrier and modifier and the temperature on the equilibrium distribution were evaluated. Relationships for the equilibrium distribution were developed and the calculated data were compared with the measured data. In the case of non-polar kerosene solvent, good agreement was found between the calculated and measured values. With the polar solvent, butylacetate, the physical extraction also had to be taken into account. By means of the developed relationships the adduct formation constants were determined for the extraction systems investigated. In order to investigate the selectivity of the carriers, tests were also performed to separate lactic acid from acetic and citric acid in model media and in fermentation broths. The separation of the acids is only possible in a multistage process. In situ extraction of lactic acid was not possible because of the toxicity of the carriers and modifiers.

Reactive extraction of lactic acid with mixed tertiary amine extractants

The mixture of tripropylamine (TPA) and trioctylamine (TOA) dissolved in 1-octanol/n-heptane was used in the reactive extraction of (L+)lactic acid in aqueous solution. Maximum distribution coefficients were obtained in the range from 6:4 to 8:2 weight ratio of TPA/TOA at 5% (w/w) lactic acid in aqueous phase and their extraction efficiencies were above 90%. By introducing TPA into TOA, the third phase formation could be overcome, thereby, the settling time is shorter than in the case of TOA only.

Reactive extraction of lactic acid in a packed column

Reactive extraction of lactic acid was performed continuously in a packed column. The 0.6 M trioctylamine (TOA)/l-chlorobutane system was used as an extradant. The initial concentration of lactic acid was 10 wt% based on fermentation results. Raschig rings (5 and 7 mm diameter) were used to measure hydrodynamic data. Disperse phase holdup was nearly constant at Vd<0.8Vd,f.It can be seen that the flooding data obtained from this study were consistent with the literature. NTU and HTU were calculated. NTU varied from 1 to 2 and HTU from 96 cm to 44 cm with variation of Vd. The overall mass transfer coefficients of the continuous phase were nearly constant to 8.98x 10-5 mol/cm2s with variation of Vd.

Water-Enhanced Solubilities of Lactic Acid in Reactive Extraction Using Trioctylamine/Various Active Diluents Systems

ABSTRACT Trioctylamine (TOA) was used as the extraction agent for reactive extraction in various active diluents. Equilibrium and hydration data for various active diluents were obtained in 0.6 M TOA systems. From these data we divided the active diluents used into three classes: active diluents containing chlorine atoms, carbon-bonded oxygen donor active diluents, and phosphorus-bonded oxygen donor active diluents. This classification was based on the characteristic groups of active diluents. The amounts of lactic acid and water in the organic phase were strongly affected by physical extraction of the active diluents. The relationships between coextracted water and lactic acid extracted were represented by slopes in drawings. The sensitivity index, which is defined as the inverse of a slope, was introduced as the measure of the water-enhanced solubilities of lactic acid. Factors affecting the reactive extraction of lactic acid and water, such as the type of active diluents, the moles of amine used, and the bulkiness of the active diluents, were explained based on the characteristic groups of the active diluents.