Extraction Of Formic Acid Research Articles

Vapor-Liquid Equilibrium of System Comprising Green Solvents: A Holistic Review

Abstract: The design and operation of distillation columns is based on vapor-liquid equilibrium data, which is a necessity for the chemical industry. In recent years, chemical industry has embraced green chemistry and sustainable development. Furthermore, green solvents are more environmentfriendly and cleaner than conventional solvents and thus offer a good alternative. Very limited work has been reported in the literature that focuses on the generation of isobaric/isothermal vapor-liquid equilibrium (VLE) data of systems comprising green solvents. In this paper, reported VLE data are explored for three emerging green solvents, such as cyclopentyl methyl ether (CPME), γ- valerolactone (GVL), and 2-methyltetrahydrofuran (2-MeTHF). Emerging green solvents have favorable environmental, health, and safety characteristics, making them attractive alternatives for a wide range of applications. The study focuses on two critical separations; the extraction of formic acid from Power-to-X chemical processes and purification of acetic acid from chemical synthesis or fermentation processes. Both processes are integral parts of the chemical industry's sustainable development. To facilitate these separations, accurate VLE data for these green solvents with acetic acid/formic acid systems are essential. The paper reviews literature related to VLE data for systems involving these green solvents. It provides insights into the experimental conditions, equipment, analysis methods, thermodynamic models, and error-minimizing functions used in the previous studies. The researchers can refer to this information as a useful reference prior to the VLE experimentation and modeling of systems comprising these three green solvents. Moreover, the paper presents an overview of recent research on green solvents and their applications, illustrating their versatility and potential for various industrial processes. Research efforts are needed to generate VLE data for green solvent systems and support the chemical industry in transitions towards more sustainable practices.

Conceptual study on extraction of formic acid from the electrolyte after electroreduction of CO2: Desalination and dehydration using a high-silica chabazite zeolite membrane

Here, we propose a two-step pervaporation system with a high-silica CHA (chabazite) membrane, which has sufficient resistance to water and acid, to demonstrate the extraction and condensation of the formic acid formed by electroreduction of CO2. The kinetic diameters of water and formic acid are similar and smaller than the pore size of CHA, while the hydrated electrolyte ions (e.g., K+ and Cl−) are larger than the pore size of CHA. Consequently, the electrolyte ions are separated from the mixture of water and formic acid in the first desalination process, and then water molecules are easily removed from the mixture in the second dehydration process. From 300 ml of an approximately 3 wt% formic acid aqueous solution containing 0.5 M KCl, 10 ml of 18.2 wt% formic acid was obtained.

Process intensification in reactive extraction by phase inversion in gas/liquid/liquid microdispersion system

Reactive extraction is widely applied to wastewater treatment, hydrometallurgy, and other industries. In this study, process intensification in reactive extraction of formic acid at an aqueous-to-oil phase ratio of 75:1 was conducted, by developing microdispersed liquid/liquid and gas/liquid/liquid systems with phase inversion. In two of the gas/liquid/liquid modes, the Murphree efficiency reached 90% within 2.0 s, which was below 28% within 28.3 s when it was carried out with millimeter-dispersed emulsion systems. The effects of phase inversion and the addition of microbubbles were systematically studied. Uniform correlations were developed to investigate the intensification effect of microbubbles in mass transfer during the formation stage in six gas/liquid/liquid dispersion methods and mass transfer during the flowing stage in four (G + O)/W emulsion systems. The most effective modes were recommended by studying process intensification fundamentals in different gas/liquid/liquid modes. This study provided simple and effective methods for process intensification of reactive extraction.

Reaction Extraction of Levulinic Acid and Formic Acid from Cellulose Deep Hydrolyzate

Levulinic acid (LA), a platform chemical with high added value, can be obtained by deep hydrolysis of cellulose, but accompanied by the production of formic acid (FA). Due to its high water content, the recovery of levulinic acid and formic acid from aqueous solution consumes a lot of energy in industry. This paper will use the method of reactive extraction to explore the optimal conditions for the recovery of levulinic acid and formic acid from deep hydrolysate. First, the kinetic and thermodynamic parameters of the reaction process were studied. Then, the effects of different parameters, such as temperature, catalyst dosage, and raw material ratio, on the reaction extraction process were investigated. Finally, through the simulation and optimization of the process, the optimized recovery conditions were chosen to realize the recovery of formic acid and levulinic acid. It is found that reactive extraction can achieve the purpose of efficiently separating levulinic acid and formic acid from the aqueous solution by the yield of 99.1% and 99.9%, respectively.

Challenges in scale‐up of electrochemical CO2 reduction to formate integrated with product extraction using electrodialysis

AbstractBACKGROUNDThe concept of carbon dioxide (CO2) conversion to formate has attracted increasing interest in recent years and various small‐scale studies are present in the literature. However, upscaling of electrochemical CO2 reduction comes with many challenges and there are very few reports available on it. In this study, we present a scalable three‐chamber reactor system for electrochemical CO2 reduction to formate, a precursor suitable for the production of fuels, pharmaceuticals and fertilizers and its extraction as pure formic acid by electrodialysis.RESULTSThe reactor produced 11.7 g L–1 formic acid in 6 h, i.e. 1.95 g L–1 h–1 at −1.8 V applied potential, 5 mol L–1 KOH as an electrolyte, GDE (gas diffusion electrode) cathode with SnO2 catalyst and Nafion™ 200 membrane. The maximum Faradaic efficiency achieved was 38%. In addition, recovery of the formate is equally important as its production for use as feedstock to form chemicals. We therefore also investigated the extraction of formic acid through conventional electrodialysis (CED) and bipolar membrane electrodialysis (BMED). The formic acid was extracted with 88% recovery using CED and 46% with BMED. Furthermore, BMED resulted in recovery of >95% K+ as base and 12 L pure CO2 for possible recycling to the electrochemical cell.CONCLUSIONWe consider this study to provide essential empirical evidence on factors influencing the scale‐up and subsequent performance of a liquid electrolyte‐based electrochemical CO2 reduction reaction (CO2RR) system to formate and its extraction at scale. However, optimized systems and operating strategies still need further investigation, and constituent materials, particularly in terms of membranes and cathode catalyst, need to be developed. © 2021 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

Liquid-Liquid Extraction of Formic Acid with 2-Methyltetrahydrofuran: Experiments, Process Modeling, and Economics.

Formic acid (FA) is an interesting hydrogen (H2) and carbon monoxide (CO) carrier that can be produced by the electrochemical reduction of carbon dioxide (CO2) using renewable energy. The separation of FA from water is challenging due to the strong (cross)association of the components and the presence of a high boiling azeotrope. For the separation of dilute FA solutions, liquid–liquid extraction is preferred over conventional distillation because distilling large amounts of water is very energy-intensive. In this study, we use 2-methyltetrahydrofuran (2-MTHF) to extract FA from the CO2 electrolysis process, which typically contains <20 wt % of FA. Vapor–liquid equilibrium (VLE) data of the binary system 2-MTHF–FA and liquid–liquid equilibrium (LLE) data of the ternary system 2-MTHF–FA–water are obtained. Continuous extraction and distillation experiments are performed to test the extraction power and recovery of 2-MTHF from the extract. The VLE and LLE data are used to design a hybrid extraction and distillation process to produce a commercial grade product (85 wt % of FA). A detailed economic analysis of this hybrid extraction–distillation process is presented and compared with the existing FA separation methods. It is shown that 2-MTHF is a cost-effective solvent for FA extraction from dilute streams (<20 wt % FA).

Extraction of formic acid from aqueous solution using polyethylene glycol /phosphate salt aqueous two-phase system

ABSTRACT In this investigation, an aqueous two-phase system method (ATPS) utilised to the assessment of the formic acid extraction. ATPS includes the polymer PEG (4000 and 8000) and different phosphate salts. Formic acid extraction modelled by an artificial neural network based on PEG molecular weight, salt concentration, temperature, and pH. The most effective operating condition obtained by MW = 4000, Salt concentration 25%, temperature 298 K, and pH = 4. The Maximum extraction efficiency of formic acid was 89% at optimised conditions. A comparison of experimental data and the artificial neural network (ANN) shows the high capability of ANN to predict the extraction efficiency.

Delignification of Pinecone and Extraction of Formic Acid in the Hydrolysate Produced by Alkaline Fractionation.

The objectives of our research are to investigate the concept of delignification from pinecone through alkaline fractionation and then extraction of formic acid from the hydrolysate through esterification using ethanol. The pinecone is considered a promising material because of its relatively higher lignin content (35.80%) than other lignocellulosic biomass. The recovery yield of acid insoluble lignin (AIL) reached its maximum value of 79.20% at 8% NaOH, and the concentration of formic acid in the hydrolysate had its highest value under the same conditions. Moreover, the glucan content in fractionated solid remained high. The hydrolysate was subjected to esterification with ethanol under various reaction conditions for formic acid extraction, with solvent mixing ratio range: 1:1-1:4 v/v, reaction temperature range: 30-45°C, and reaction time range: 60-100min. Subsequently, the ethanol mixture (ethanol and ethyl formate) was recovered through distillation. The formic acid was extracted with more than 85% at mixing ratio of 1:2 and 45°C for all reaction times. Furthermore, salt compounds composed mainly of Na and S were recovered because of its properties not soluble in ethanol solution.

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.

Liquid–Liquid Equilibria of Formic Acid and Furfural in a Biphasic Aqueous–Organic System: Optimization of Solvent and Amine Extractant

Liquid–liquid equilibria of formic acid (FA) and furfural in a biphasic aqueous–organic system were studied. Fourteen kinds of samples with a high boiling point and a large density difference with water were first screened to measure the distribution coefficient of furfural. Eight solvents with a high furfural distribution coefficient were further screened for FA extraction. Six solvents (1,2-dimethoxybenzene, 2,4-dimethyl-1-nitrobenzene, diethyl phthalate, tributyl phosphate, dibutyl phthalate, and dibutyl sebacate) with a low FA distribution coefficient were then selected to measure the mutual solubilities at 298.15 K. Furthermore, two amine extractants (tri-n-octylamine and amine N235) were diluted in six solvents for the extraction of FA and furfural from aqueous solutions to optimize the solvent and extractant. 2,4-Dimethyl-1-nitrobenzene or diethyl phthalate was proven to be more suitable for this system. Effects of the amine extractant concentration in solvents were evaluated to balance the furfura...

Reactive extraction and recovery of levulinic acid, formic acid and furfural from aqueous solutions containing sulphuric acid

Levulinic acid (LA) can be produced from lignocellulosic materials via hydroxylation followed by an acid-catalyzed conversion of hexoses. Inorganic homogeneous catalysts are mostly used, in particular sulphuric acid, yielding a mixture of LA with sulphuric acid, formic acid (FA) and furfural. Significant attention has been paid to optimization of the yield, but purification of the LA is a challenge too. This work focuses on the separation of LA from the complex aqueous mixtures by liquid-liquid extraction. Two aqueous product feeds were considered, reflecting two different processes. One aqueous product stream contains sulphuric acid and LA, while the second product stream also contains formic FA and furfural. Furfural could be removed selectively via liquid-liquid extraction with toluene. For selective extraction of LA and FA without co-extracting sulphuric acid, 30 wt.% of trioctylphosphine oxide (TOPO) in methylisobutylketone (MIBK) was found most suitable, showing a high selectivity over sulphuric acid, and a high equilibrium partitioning of LA. When instead of MIBK, 1-octanol was applied as diluent, the co-extraction of FA was enhanced, while hexanoic acid suppressed the acid extraction. To obtain the LA pure, eventually a distillation is required, and the potential of temperature swing back extraction (TSBE) at 90 °C to pre-concentrate the acid solutions was evaluated for 30 wt.% TOPO in MIBK. This pre-concentration step increased the concentrations of LA and FA by a factor of 2.45 and 2.45 respectively, reducing the distillation reboiler duty from roughly 31.5 to 11.3 GJ per ton LA, at a cost of roughly 4.5 GJ heating duty per ton produced LA.

Design and Assessment of Hybrid Purification Processes through a Systematic Solvent Screening for the Production of Levulinic Acid from Lignocellulosic Biomass

A hybrid purification process combining extraction and distillation for the production of levulinic acid (LA), furfural, and formic acid (FA) from lignocellulosic biomass was studied. The effective process depends on the choice of appropriate extraction solvent. A comprehensive procedure of solvent selection for the LA production process was developed. A range of solvents were first evaluated by solvent screening, and processes using the three most promising solvents, including methyl isobutyl ketone (MIBK); furfural and octanol were then designed and optimized using an Aspen Plus simulator. These processes were evaluated in terms of the energy consumption, total annual cost, and environmental impact. As a result, MIBK showed the most favorable equilibrium for the extraction of LA but was unfavorable for FA extraction. Octanol showed not only the most favorable result in the extraction of FA, but was also favorable for the extraction of furfural and LA. Interestingly, furfural could extract more LA than o...

Catalytic oxidation of biomass to formic acid in aqueous solutions using vanadium-containing catalysts

Formic acid (FA) is an important material in the chemical industry, and the preparation of FA from biomass could provide a sustainable strategy for the large-scale production of FA. Vanadium (V)-containing catalysts have recently been reported to catalyze the conversion of biomass to FA with a high level of selectivity under aqueous conditions using molecular O 2 as an oxidant. These catalysts mainly include V-containing heteropoly acid, NaVO 3 /H 2 SO 4 and VOSO 4 . In this article, we have provided a detailed review of the performances of these three catalytic systems for the conversion of biomass into FA. This review is mainly focused on four key areas of research, including the mechanisms associated with this transformation, the relationships between various reactions, methods for the separation of FA from the aqueous solution and the recyclability of the catalytic systems. Vanadium-containing catalytic systems can be used to generate FA from numerous bio-based carbohydrates, including sugars, cellulose and hemicellulose, with a high level of selectivity. The active catalytic species in these processes is known to be V 5+ , and these processes can be explained in terms of an electron transfer-oxygen transfer mechanism, where the vanadium species (including V-containing heteropoly acid and VO 2 + ) receives two electrons from the substrate in exchange for one oxygen atom to form FA. Among the various reactions occurring in the catalytic system, the hydrolysis of the biomass and the selective oxidation of the biomass to FA are competitive, and variations in the main reaction parameters can lead to significant changes in the balance between these two reactions. The direct separation of FA from the aqueous reaction mixture by distillation is difficult, and the extraction of FA by organic solvents is by far a relatively feasible method. Among the extraction agents evaluated for this purpose, n-butyl ether and ethyl ether have been reported to be useful for the extraction of FA from catalytic systems using V-containing heteropoly acid and NaVO 3 /H 2 SO 4 as catalysts, respectively. In terms of the recyclability of the NaVO 3 /H 2 SO 4 system, the activity remained largely unchanged after several runs when cellulose and real lignocellulose were employed as substrates. Finally, the problems associated with this process for the conversion of biomass were analyzed and several new strategies have been proposed to further develop the processes involved in the preparation of FA from biomass. Research towards developing a better understanding of the reaction mechanism associated with this process has focused predominantly on the oxidation of potential model compounds and ambiguous inferences. Further studies on the mechanism should focus on the detection of the real coordinated complex formed by the catalyst and substrate through various testing methods. Research on real lignocellulose has so far been inefficient, because of the lack of studies towards lignin conversion and the effect of ash. The separation of FA from an aqueous solution still represents a significant challenge to the industrial application of biomass for production of FA.

Comparison of solvents for the recovery of low-molecular carboxylic acids and furfural from aqueous solutions

Liquid–liquid extraction of formic acid, acetic acid and furfural from an aqueous synthetic acid hydrolysis process stream is studied. Different types of extractants are first evaluated and two solvents that can efficiently recover the compounds, 2-methyltetrahydrofuran (2-MTHF) and tri-n-octylamine in toluene (Alamine 336-toluene) are then studied further. Important considerations in solvent selection were the efficiency of solvent regeneration and the recovery of the extractives from the loaded solvents. Solvent regeneration experiments were carried out under a vacuum in a spinning band distillation unit. Both solvents showed good regeneration characteristics. The rate of phase separation for Alamine 336 increased, without the formation of an emulsion, when performing extractions at low mixing rates. The use of toluene as a diluent for Alamine 336 prevented the formation of a third intermediate phase. In general, the equilibrium favors the extraction of formic acid for Alamine 336 and the extraction of furfural for 2-MTHF. For acetic acid there was only a small difference in the distribution coefficients for both solvents.

Investigation of Formic Acid Separation from Aqueous Solution by Reactive Extraction: Effects of Extractant and Diluent

This study aims to investigate the extraction of formic acid by a high molecular-weight aliphatic amine, tridodecylamine (TDA), and a phosphorus-bonded, oxygen-containing extractant, tributyl phosphate (TBP), dissolved in five different diluents (ethyl valerate, diethyl adipate, diethyl sebacate, 1-octanol, and heptane) each. The experiments were carried out at 298.15 K. Comparisons of the results were made using the distribution coefficient, loading factor, separation factor, and the percentage of extraction yield. The results demonstrated that combination of TDA and diethyl adipate had the greatest synergistic effects with a distribution value of 6. The maximum value of the extraction efficiency was found to be 87 % with a 1.09 mol·L−1 concentration of TDA in diethyl adipate.

Detoxification of biomass hydrolysates by reactive membrane extraction

Economical conversion of lignocellulosic biomass into biofuels is essential to reduce the world's dependence on fossil fuels. The typical biochemical process for biomass conversion includes a thermochemical pretreatment step to improve enzymatic cellulose hydrolysis and to release hemicellulosic sugars from the polymer matrix. However compounds that are toxic to microorganisms in subsequent fermentation steps may also be released. This work investigates the use of membrane extraction to detoxify or remove these toxic compounds from corn stover hydrolysates pretreated using dilute sulphuric acid. Extraction of sulphuric, acetic, formic and levulinic acid as well as 5-hydroxymethylfurfural and furfural has been investigated. Octanol and oelyl alcohol were used as organic phase solvents. Alamine 336 was used as the aliphatic amine extractant. Reactive extraction of sulphuric, acetic, formic and levulinc acid was observed while 5-hydroxymethylfurfural and furfural were extracted due to their distribution in the organic solvent. Significant removal of all toxic compounds investigated was obtained as well an increase in pH from 1.0 to 5.0. As small quantities of the organic phase transferred into the hydrolysate during extraction, the toxicity of the organic phase must be considered. As it is likely that detoxification will require the use of another unit operation in combination with membrane extraction, the economical viability of the combined process must be considered.

Reactive Extraction of Formic Acid by using Tri Octyl Amine (TOA)

Distribution of formic acid (methanoic acid) between water and tri octyl amine (TOA) dissolved in various alcohols (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol) as diluents, as well as the extraction capacity of pure diluent alone have been studied at isothermal conditions. All measurements were carried out at 298.15 K. The difference between the physical extraction and reactive extraction was studied. The loading factor, T T, extraction efficiency, D E, modified separation factor, S F, and, distribution coefficients, K D were calculated. The isoamylalcohol was found most effective solvent with maximum distribution value of 14.521. Possible equilibrium complexation constants for (acid:amine) (5:1), (6:1), and (7:1) have been determined as values of about 21.8 × 103, 15.6 × 104, and 11.1 × 105 for K51, K61, and K71, respectively with isoamylalcohol. Furthermore, Linear Solvation Energy Relationship (LSER) model equation has been obtained to calculate distribution coefficients for alcohols with regression coefficient of 0.981.

Reactive Extraction of Formic Acid by Amberlite LA-2 Extractant

The reactive extraction of formic acid by Amberlite LA-2 dissolved in five different esters (dimethyl phthalate, dimethyl adipate, dimethyl succinate, dimethyl glutarate, diethyl carbonate), five different alcohols (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, decan-1-ol), and two different ketones (diisobutyl ketone (DIBK), methylisobutyl ketone (MIBK)) as diluents as well as the extraction capacity of pure diluent alone have been studied at isothermal conditions. All measurements have been carried out at 298.15 K. The comparison of physical and reactive extractions has been studied. The loading factor, TT, extraction efficiency, E, modified separation factor, SF, and distribution coefficients, KD, have been calculated. The isoamylalcohol has been found to be the most effective solvent with a maximum distribution value of 19.223. Furthermore, the linear solvation energy relationship (LSER) model equation has been obtained to calculate distribution coefficients for alcohols with an R square of 0.976.

Extraction Equilibria of Formic and Acetic Acids from Aqueous Solution by Phosphate-Containing Extractants

The purpose of this work is to study the feasibility of extraction and recovery of formic acid and acetic acid in the industry synthesis of these two acids. In this work, extraction equilibria of formic and acetic acid with kerosene solutions of such phosphate-containing extractants as trialkylphosphine oxide (TRPO) and tributyl phosphate (TBP) were studied. The solutions of formic and acetic acid in aqueous phase at equilibira ranged from 0.4 mol·L-1 to 8 mol·L-1. The influences of temperature on extraction equilibria were also studied. A model was proposed to describe the equilibria by postulating the structure of the complexes. The parameters in the model were obtained by fitting the experimental data, and the values predicted by this model are very close to the measured results.

Analysis of the Mechanism of the Decomposition−Extraction Process

In a last paper (Hu, L.; Adeyiga, A. A. 1997, 36 (6), 2375), we reported the extraction of formic acid from the reaction of sodium formate with carbon dioxide by organic tertiary amine. The process can be described by the reactions HCOONa(w)+CO 2 (g)+H 2 O(w)===NaHCO 3 (s,w)+HCOOH(w) and HCOOH(w)+NR 3 (o)===HCOOHNR 3 (o). We defined the above process as a decomposition-extraction process. The studies investigated the mechanism of the decomposition-extraction process. By engineering analysis of the process, it was found that the mass transfer of carbon dioxide from the gas phase to the aqueous phase (the aqueous solution of sodium formate or calcium chloride) proceeded essentially through the organic phase (organic tertiary amine with diluent 2-ethylhexyl alcohol) rather than directly. Then carbon dioxide in the organic phase reacted with salt in the aqueous solution to form MHCO 3 and complex NR 3 -HOOCH. The organic phase was both the extractant of formic acid and the transporter of carbon dioxide. This mechanism has been identified through the experimentation for the first time.