Extraction Of Lactic Acid Research Articles

Lactic Acid Extraction by Means of Long Chain Tertiary Amines: A Comparative Theoretical and Experimental Study

The extraction of lactic acid with different long chain (from C8 to C12) tertiary amines was studied, both theoretically and experimentally. In view to determine the concentration of free acid and bounded with extractant acid in the aqueous phase, the experimental results were treated by mass balance equations. The minimal and maximal fractions of the free acid and bounded acid were calculated for different compositions of the organic phase. The obtained results clearly showed that in general the interaction product concentration in the aqueous phase could not be neglected and, in some cases, reached more than 50% from the total acid concentration. The disparate influences of inert and active diluents (dodecane and oleyl alcohol, respectively) were elucidated. It was shown that the overall distribution coefficient depends not only on the extraction product concentration in the aqueous phase but also on the composition of the organic phase.

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

Use of 1‐hexyl‐3‐methylimidazolium bromide ionic liquid in the recovery of lactic acid from wine

AbstractBACKGROUND: Lactic acid has many different applications in a variety of industries including the food, cosmetics, packaging, leather and chemical industries. Current methodologies for lactic acid production are lengthy and complicated and more efficient methods are being sought. Some organic wastes contain lactic acid and our work investigates the use of ionic liquids (ILs) in the efficient and selective extraction of lactic acid from organic waste using wine as a model system. The ionic liquid was chosen based on its ability to selectively solvate and separate lactic acid from the remaining bulk waste material.RESULTS: Several ILs including 1‐hexyl‐3‐methylimidazolium chloride (hmimCl), 1‐hexyl‐3‐methylimidazolium bromide (hmimBr), 1‐hexyl‐3‐methylimidazolium iodide (hmimI) and N‐hexylpyridinium iodide (hpyrI) have been synthesized in high yield (68‐95%) using microwave technology. Lactic acid is soluble in each of the ILs synthesized with optimum results achieved with hmimBr where lactic acid is miscible in all proportions. HmimBr has been used to successfully separate and extract lactic acid from wine as confirmed by FTIR spectroscopy. Furthermore, it has been possible to recover the IL for recycle in subsequent extraction cycles where the efficiency for the extraction process increases with each recycle.CONCLUSION: HmimBr has been used for the first time in a novel process for the separation and recovery of lactic acid from wine, as confirmed by FTIR spectroscopy. This work demonstrates a novel process which can be applied to the recovery of lactic acid from organic waste. Copyright © 2012 Society of Chemical Industry

Effects of Different Neutralizing Agents on D-(-)-Lactic Acid Fermentation by <i>Escherichia coli </i>W

Effects of NH4OH, KOH, Ca (OH) 2, CaCO3, and a mixture of CaCO3 and NH4OH as neutralizing agents for efficient recovery of lactic acid fermented by Escherichia coli W were investigated. Maximum productivities of lactic acid were 11.3 g/L, 10.7 g/L, 5.5 g/L, 11.9 g/L, and 12.8 g/L respectively. The mixed neutralizing agent of CaCO3 and NH4OH was testified to be better than any single neutralizer used in this study. CaCO3 was the most appropriate neutralizer among the first four neutralizers, which could make lactic acid precipitate in the form of calcium lactate, and facilitate the downstream separation and extraction of lactic acid. Furthermore, it was a slow type of mild neutralizer and had a limited capacity to regulate pH. NH4OH could regulate pH easily, and it was beneficial to cell growth as an additional nitrogen source, thus resulting in a relatively lower lactic acid production.

Asymmetric lactic acid esterification with biocatalysts in ionic liquid

Biodegradability and environmentally friendly technologies recently came into prominence; this is the reason why we assayed to develop a new “green” technology for L-lactic-acid (LLA) production. Racemic lactic acid (rLA) mixture produced by chemical industry is difficult to handle. The product of esterification with low carbon chain alcohols has higher volatility than lactic acid (LA) itself, therefore it can be more effectively separated. Our reactions were carried out with biocatalysts (enzymes) — some of them prefer reactionswith L-enantiomer — result in enantioselective esterification. After LLA ester production the hydrolysis leads to separated LLA, which is the starting material of a biodegradable plastic. Our aim was to achieve enantioselectivity in phosphonium-type ionic liquid solvents by the optimization of several parameters, such as temperature, substrate molar ratio, amount of IL, water content. Reasonable results were achieved with three types (Candida antarctica, Candida rugosa, AMANO PS-IM) of lipases. The use of enzymes and ionic liquids can make the technology “greener”, where an ingredient of a biodegradable plastic can be produced. The toxic heavy metals or hazardous acids can be replaced by biocatalyst (enzymes). These intermediates are re-usable, and they work at lower temperature, than conventional catalysts, thus the operational costs can be reduced. Ionic liquids — compared with conventional organic solvents — have insignificant vapour pressure, they are non-flammable and re-usable after a purification process, furthermore they can betailor made for a certain application. It is not negligible that the structure affects the environmental features like biodegradability or toxicity. The high lactic acid dissolving capacity is the reason why phosphonium-type ionic liquids were used. There are research teams, apply them for lactic acid extraction from fermentation broth.

Lactic Acid Extraction and Enzymatic Esterification for the Ethyl Lactate Production from Rice

Polylactic acid has received much attention because of its biodegradable characteristics. However, to produce the polylactic acid, enormous energy is required at the current purification processes developed up to now. In this work, in order to reduce energy consumption, we proposed a novel purification method which combines lactic acid extraction and enzyme esterification instead of the dehydration and the chemical esterification which are conventionally used. As a result, the new purification method is found to be excellent as the solvents used in this work. It revealed that some solvents (diethyl ether, tert-butyl methyl ether, and methy isobuthyl ketone) have excellent abilities for both lactic acid extraction and enzymatic esterification.

Extraction and separation of D/L-lactic acid in simulated fermentation broth

The recovery of lactic acid from fermentation broth plays an important part in production of lactic acid. In this case, the extraction of lactic acid from simulated fermentation broth was processed by tri-n-octylamine dissolved in oleyl alcohol. The extraction efficiency was investigated with several variables, and the optimal condition of extraction of lactic acid (10 mg mL−1) from aqueous solution was tri-n-octylamine/oleyl alcohol (30/70, v/v) and solvent phase/ fermentation (1/2, v/v) stirred for 60 min under room temperature. The optimal back extraction of lactic acid was obtained by hot water (∼90 °C) with solvent phase/water (1/4, v/v). The back extracted racemic lactic acid was direct enantiomeric analyzed and separated by chiral ligand chromatography due to strict requirement of absolute configuration in pharmaceutical field and food science. The effect of various parameters on enantioselectivity was discussed and the (L)-phenylalaninamide·HCl (6.0 mmol L−1) and CuSO4·5H2O (3.0 mmol L−1) dissolved in methanol/water (5/95, v/v) at pH=6.0 was the suitable mobile phase for chiral ligand exchange separation of (D, L)-lactic acids. By the investigations, a convenient systemic method was established for extraction and separation of (D, L)-lactic acid.

Aqueous Two-Phase Extraction of Lactic Acid: Optimization by Response Surface Methodology

In this study a suitable alcohol/salt aqueous two-phase (ATP) system was selected for the recovery of lactic acid from an aqueous solution. From the different ATP systems studied, the ethanol/dipotassium hydrogen phosphate ATP system appeared to be favorable. To examine the potential of this ATP system, the extraction yield of lactic acid in aqueous solutions was optimized with the response surface methodology. The parameters studied were concentrations of ethanol (22.00–38.80%, w/w), dipotassium hydrogen phosphate (15.00–31.80%, w/w) and lactic acid (26.36–93.64 g/L). The optimum conditions were found to be 30.23% w/w ethanol, 18.40% w/w dipotassium hydrogen phosphate, and 80 g/L lactic acid. Under these conditions, a favorable extraction yield of lactic acid was obtained. The maximum partition coefficient of lactic acid and extraction yield was determined as 2.26 and 87%, respectively. The optimum extraction conditions were then used to guide the recovery of lactic acid from a real fermentation broth. As a result, the partition coefficient and extraction yield of lactic acid reached 2.06–80%, respectively.

The extraction of lactic acid by emulsion type of liquid membranes using alamine 336 in escaid 100

AbstractThe extraction of lactic acid from aqueous solutions through an emulsion liquid membrane containing Alamine 336 as carrier was investigated. The influence of mixing speed, diluent type, surfactant concentration, extractant concentration, feed solution pH, stripping concentration, phase ratio, and feed concentration were examined. Liquid membrane consists of a diluent (n‐heptane, toluene, kerosene, Escaid 100, and Escaid 200), a surfactant (Span 80) and an extractant (Alamine 336), and Na2CO3 were used as a stripping solution. It is possible to extract 91% of lactic acid from aqueous solutions using Alamine 336 in Escaid 100, as an extractant and a diluent respectively.

Extraction of Lactic Acid Using Long Chain Amines Dissolved in Non-Polar Diluents

The present paper deals with the effect of di- and tri-n-octylamine (DOA and TOA) dissolved in non-polar diluents or the mixture of non-polar diluents and modifier on the extraction of L-lactic acid from aqueous solutions. The amount of lactic acid extracted to the organic phase at equilibrium is dependent on the initial concentration of lactic acid in the aqueous phase as well as on that of amine in the organic phase. The results confirmed that almost the entire portion of lactic acid can be effectively extracted when the DOA concentration exceeds the initial concentration of lactic acid in the aqueous phase, and that TOA has little ability for the extraction when it is dissolved in non-polar diluent. Adding a modifier (decanol) to a non-polar diluent is also demonstrated to be effective for improving the extraction ability of TOA. The influence of the equilibrium pH value on the distribution ratio of lactic acid can be reasonably characterized by modifying the conventional ion-pair extraction model.

The Role of Lactic Acid Adsorption by Ion Exchange Chromatography

BackgroundThe polyacrylic resin Amberlite IRA-67 is a promising adsorbent for lactic acid extraction from aqueous solution, but little systematic research has been devoted to the separation efficiency of lactic acid under different operating conditions.Methodology/Principal FindingsIn this paper, we investigated the effects of temperature, resin dose and lactic acid loading concentration on the adsorption of lactic acid by Amberlite IRA-67 in batch kinetic experiments. The obtained kinetic data followed the pseudo-second order model well and both the equilibrium and ultimate adsorption slightly decreased with the increase of the temperature at 293–323K and 42.5 g/liter lactic acid loading concentration. The adsorption was a chemically heterogeneous process with a mean free energy value of 12.18 kJ/mol. According to the Boyd_plot, the lactic acid uptake process was primarily found to be an intraparticle diffusion at a lower concentration (<50 g/liter) but a film diffusion at a higher concentration (>70 g/liter). The values of effective diffusion coefficient Di increased with temperature. By using our Equation (21), the negative values of ΔG° and ΔH° revealed that the adsorption process was spontaneous and exothermic. Moreover, the negative value of ΔS° reflected the decrease of solid-liquid interface randomness at the solid-liquid interface when adsorbing lactic acid on IRA-67.Conclusions/SignificanceWith the weakly basic resin IRA-67, in situ product removal of lactic acid can be accomplished especially from an open and thermophilic fermentation system without sterilization.

Solid phase extraction of lactic acid from fermentation broth by anion-exchangeable silica confined ionic liquids

Three anion-exchangeable, silica-confined ionic liquids were synthesized for solid phase extraction of lactic acid from fermentation broth, followed by high-performance liquid chromatography coupled to ultraviolet detection. By comparing the adsorption isotherms of lactic acid on different silica-confined ionic liquids, interactions between the lactic acid and sorbents were investigated. The adsorbed amounts were then fitted into different adsorption isotherm equations; finally, the Langmuir equation was selected. Then the imidazolium silica with the highest adsorption capacity of lactic acid was packed into a cartridge for solid phase extraction. The loading volume of the cartridge was optimized by the Langmuir equation and geometry. After washing with distilled water and eluting with 0.25 mol L −1 of an HCl solution, the lactic acid was separated from interference with a recovery yield of 91.9%. Furthermore, this kind of anion-exchangeable material exhibited potential for industrial applications and separation of other anionic bioactive compounds.

Extraction of lactic acid from technological (concentrated) solutions

The extraction of lactic acid from technological solutions by different extracting agents and their mixtures was studied. It was established that the most effective extraction of lactic acid is reached in systems with mixtures of trioctylamine and tributyl phosphate. The reextraction of lactic acid from the organic phase is performed by water.

Reactive extraction and LSER model consideration of lactic acid with tripropylamine+organic solvent systems from aqueous solution at room temperature

The extraction of lactic acid was done by tripropylamine (TPA) dissolved in seven single solvents (isoamyl alcohol, heptan-1-ol, hexan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol, and dodecanol). All measurements were carried out at 298.15 K. The extent to which the organic phase may be loaded with lactic acid is expressed as loading ratio, Z , its value extraction efficiencies, E , and overall particular distribution coefficients, D , were calculated. Equilibrium complexation constants for (acid:amine) (1:1), (1:2) have been determined according to Bizek's approach. The maximum removal of lactic acid accomplished was about 81% with isoamyl alcohol having 1.935 mol dm − 3 initial concentration of TPA. All of the obtained data have been correlated by linear solvation energy relationship (LSER) model. LSER model results were compared with the experimental results and well agreement between them was observed. Regression coefficient ( R 2 ) of LSER model is 0.972.

Detailed Investigation of Lactic Acid Extraction with Tributylphosphate Dissolved in Dodecane

The aim of the present study was to study the extraction of lactic acid with tributylphosphate (TBP) dissolved in a diluent (dodecane) over a broad range of acid concentrations and solvent compositions, to determine the apparent equilibrium constants and the number of reacting extractant molecules, and to elucidate the influence of different factors (preliminary washing of organic phase, change of phase volumes, pH at equilibrium, acid concentration) on the extraction of the acid. It was found that the change of phase volumes after extraction should be taken into account for the calculation of different process parameters. The preliminary washing of the extractant does not significantly affect the overall distribution coefficients.

Diazoxide protects myocardial mitochondria, metabolism, and function during cardiac surgery: A double-blind randomized feasibility study of diazoxide-supplemented cardioplegia

The study was designed to assess whether diazoxide-mediated cardioprotection might be used in human subjects during cardiac surgery. Forty patients undergoing coronary artery bypass grafting were randomized to receive intermittent warm blood antegrade cardioplegia supplemented with either diazoxide (100 micromol/L) or placebo (n = 20 in each group). Mitochondria were assessed before and after ischemia and reperfusion in myocardial biopsy specimens. Myocardial oxygen and glucose and lactic acid extraction ratios were measured before ischemia and in the first 20 minutes of reperfusion. Hemodynamic data were collected, and troponin I, creatine kinase-MB, and N-terminal prohormone brain natriuretic peptide levels were measured. All outcomes were analyzed by using mixed-effects modeling for repeated measures. No deaths, strokes, or infarcts were observed. Patients received, on average, 36.2 +/- 1.2 mg of diazoxide and 37.3 +/- 1.9 mg of placebo (P = .6). Diazoxide added to cardioplegia prevented mitochondrial swelling (8899 +/- 474 vs 9273 +/- 688 pixels before and after the procedure, respectively; P = .6) compared with that seen in the placebo group (8474 +/- 163 vs 11,357 +/- 759 pixels, P = .004). No oxygen debt was observed in the diazoxide group. Glucose consumption and lactic acid production returned to preischemic values faster in the diazoxide group. The following hemodynamic parameters differed between the diazoxide and placebo groups, respectively, in the postoperative period: cardiac index, 3.0 +/- 0.09 versus 2.6 +/- 0.09 L . min(-1) . m(-2) (P = .002); left cardiac work index, 2.81 +/- 0.07 versus 2.31 +/- 0.07 kg/m(2) (P < .001); oxygen delivery index, 420 +/- 14 versus 377 +/- 13 mL . min(-1) . m(-2) (P = .03); and oxygen extraction ratio, 29.3% +/- 1.1% versus 32.6% +/- 1.1% (P = .02). Postoperative myocardial enzyme levels did not differ, but N-terminal prohormone brain natriuretic peptide levels were lower in the diazoxide group (120 +/- 27 vs 192 +/- 29 pg/mL, P = .04). Supplementing blood cardioplegia with diazoxide is safe and improves myocardial protection during cardiac surgery, possibly through its influence on the mitochondria.

Investigation of a dual‐particle liquid–solid circulating fluidized bed bioreactor for extractive fermentation of lactic acid

A dual-particle liquid-solid circulating fluidized bed (DP-LSCFB) bioreactor has been constructed and investigated for the simultaneous production and extraction of lactic acid using immobilized Lactobacillus bulgaricus and ion-exchange resins. The apparatus consisted of a downer fluidized bed, 13 cm I.D. and 4.75 m tall, and a riser fluidized bed, 3.8 cm I.D. and 5.15 m in height. The lactic acid production and removal was carried out in the downer, while the riser was used for the recovery of lactic acid. A continuously recirculating bed of ion-exchange resin was used for adsorption of the produced acid as well as for maintaining optimum pH for bioconversion, thus eliminating the need for costly and complex chemical control approach used in conventional techniques. Studies using lactic acid aqueous solution as feed and sodium hydroxide solution as regeneration stream showed 93% lactic acid removal from the downer and 46% recovery in the riser under the conditions investigated. Such results prove the functionality of using the newly developed bioreactor design for the continuous production and recovery of products of biotechnological significance.

Effects of Organic Phase, Fermentation Media, and Operating Conditions on Lactic Acid Extraction

Lactic acid has extensive uses in the food, pharmaceutical, cosmetic and chemical industry. Lately, its use in producing biodegradable polymeric materials (polylactate) makes the production of lactic acid from fermentation broths very important. The major part of the production cost accounts for the cost of separation from very dilute reaction media where productivity is low as a result of the inhibitory nature of lactic acid. The current method of extraction/separation is both expensive and unsustainable. Therefore, there is great scope for development of alternative technology that will offer efficiency, economic, and environmental benefits. One of the promising technologies for recovery of lactic acid from fermentation broth is reactive liquid-liquid extraction. In this paper the extraction and recovery of lactic acid based on reactive processes is examined and the performance of a hydrophobic microporous hollow-fiber membrane module (HFMM) is evaluated. First, equilibrium experiments were conducted using organic solutions consisting of Aliquat 336/trioctylamine (as a carrier) and tri-butyl phosphate (TBP)/sunflower oil (as a solvent) The values of the distribution coefficient were obtained as a function of feed pH, composition of the organic phase (ratio of carrier to solvent), and temperature (range 8-40 degrees C). The optimum extraction was obtained with the organic phase consisting of a mixture of 15 wt % tri-octylamine (TOA) and 15% Aliquat 336 and 70% solvent. The organic phase with TBP performed best but is less suitable because of its damaging properties (toxicity and environmental impact) and cost. Sunflower oil, which performed moderately, can be regarded as a better option as it has many desirable characteristics (nontoxic, environment- and operator-friendly) and it costs much less. The percentage extraction was approximately 33% at pH 6 and at room temperature (can be enhanced by operating at higher temperatures) at a feed flow rate of 15-20 L/h. These results suggest that the hollow-fiber membrane process yields good percentage extraction at the fermentation conditions and its in situ application could improve the process productivity by suppressing the inhibitory effect of lactic acid.

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.

Equilibrium Studies of the Extraction and Re-extraction of Lactic Acid

Equilibrium studies on the extraction of lactic acid in various organic phases and its re-extraction into aqueous solutions have been carried out. This includes a variety of experimental situations: using only solvents, single carriers with solvent, mixed carriers with solvent and with mixed solvents. The organic phase consists of a carrier (or a mixture of carrier) dissolved in a solvent (or a mixture of solvents). The extraction and re-extraction processes have been characterized by using distribution coefficient for the respective processes. The values of the distribution coefficient have been obtained by varying the operating conditions (i) for extraction: feed solution pH, types of carrier and its concentrations, solvent and its concentration in the organic phase; and (ii) for re-extraction: the type, pH, and concentration of recovery solution. It was found that 20 wt % of trioctylamine (an ionic carrier) dissolved in tributyl phosphate (an active solvent) was found to be the best extracting phase...