Deacidification Rate Research Articles

Impact of deacidification processes on the quality and oxidative stability of walnut oil

In order to select an appropriate deacidification process and improve the quality of walnut oil, low-temperature cold-pressed crude walnut oil was used as raw material. Deacidified walnut oil was prepared using three deacidification processes: chemical deacidification (CD), adsorption deacidification (AD), and molecular distillation deacidification (MDD). The physicochemical properties, nutritional components, and in vitro antioxidant activities of the resulting deacidified walnut oils were comparatively analyzed. The results indicate that the fatty acid content in walnut oil exhibits fluctuating changes during the three different deacidification processes. The MDD shows a higher deacidification rate, reaching 94.06%, which is superior to the other two methods. Additionally, the AD retains more total phenols and tocopherols, with retention rates of 95.79% and 74.62%, respectively; whereas MDD is more effective at retaining phytosterols, achieving a retention rate of 98.09%. All these methods displayed positive impacts on the in vitro antioxidant capacity and oil stability of walnut oil, with ferric-reducing antioxidant power (FRAP) content and oxidative stability time were significantly reduced.whencompared to the untreated crude oil Among them, AD had the greatest impact on oxidative stability index (OSI) , with its decreasing from 2.06 h to 0.82 h. Overall, compared to CD or MDD, the AD has best application prospects in preserving nutritional components.

Structural analysis of petroleum acids in highly acidic crude oil and deacidification using organic amines

Naphthenic acids, polar compounds with carboxylic group, are commonly found in crude oils as product of biodegradation. The presence of NAs in oil can cause corrosion of processing equipment and pipelines and can lead to degradation of crude oil quality. Qilu high acid crude oil was designated for research, from which the acidic fraction was separated by caustic extraction. Elemental analysis, Fourier transform infrared spectroscopy, nuclear magnetic resonance and high-resolution Orbitrap mass spectrometry were used for characterization. The structure of the acidic fraction was verified to be naphthenic acids primarily, and the average molecular formula was obtained. Based on the derivation of the modified B-L method, the average molecular structure was monocycloalkyl benzoic acid with single carboxyl substitution The effects of various depickling solvents and process conditions on deacidification results as well as product were investigated and illustrated with potentiometric titration, UV spectroscopy, zeta potential test and Karl Fischer method. Among the three groups of deacidifiers, inorganic bases represented by sodium hydroxide have the best deacidification efficiency, reaching 83.5 %. But the emulsification caused by sodium naphthenate is severe and the emulsion is stable, making it difficult to achieve oil–water separation. Polyethylene polyamines cause the least emulsification. Moreover, as the number of amino groups in the monomer rises, the number of sites that can be neutralized with petroleum acids increases, and the deacidification rate rises. As result, the most suitable deacidifier for processing is ethanolamine, which can reduce the total acid number of crude oil to 0.47 after three stages of deacidification at 70 °C and a concentration of 10 %.

Combined removal experiment of multiple impurities from W/O emulsions under high frequency pulsed electric field: Study on laws of desalination, decalcification, and deacidification

AbstractElectrocoalescence is widely used to dehydrate crude oil, but impurities in crude oil are extremely complex, which greatly weaken the effect of dehydration. To understand the coupling law of various impurities, a static demulsification experiment was conducted under a high frequency and high voltage pulsed electric field to investigate the effects of electric field parameters (voltage, frequency, pulse width ratio), emulsification strength, electrocoalescence time, water content, acid value, injection alkali ratio, calcium content, decalcification agent concentration and removal process on desalination, decalcification, and deacidification. The results showed that the desalination and decalcification rates varied synchronously with the electric field parameters and water content. Additionally, the desalination and decalcification rates decreased with the emulsification strength, alkali injection ratio, acid value, and calcium content. Further, they increased first and then decreased with decalcifier concentration. The deacidification rate did not vary with the electric field parameters, but it strengthened with the water content and alkali injection ratio. Conversely, it decreased with the acid value, calcium content, and decalcifier concentration. Additionally, it increased first and then decreased with the emulsification intensity. The best removal procedure is deacidification followed by decalcification. These findings are helpful to achieve the combined removal of various impurities in crude oil.

Deacidification of Acidic Oil Catalyzed by Sulfonated Mesoporous Silica for Biodiesel Production: Optimization, Kinetic, and Enhancement by Using Calcined Kaolin

Acidified oil is characterized as high acid value. Hence, deacidification is indispensable in biodiesel production from acidic oil. Heterogeneous catalysts have many advantages over homogeneous counterparts in deacidification of acidic oil. Therefore, in the present work, sulfonated mesoporous silica (SMS) was prepared and characterized, followed by the systematical investigation on the effect of reaction variables on the deacidification rate (DR). Furthermore, response surface methodology (RSM) was employed to optimize the reaction parameters. Results showed that the optimal studied reaction variables for the deacidification process were as follows: reaction temperature 65 °C, methanol to oleic acid ratio 35:1, catalyst loading of 2%, in which, deacidification rate of 97.78% could be achieved. DR of 62.52% could still be obtained after catalyst had been used for four consecutive cycles. Finally, significant enhancement of DR could be achieved by using calcined kaolin to assist the deacidification of acidified oil with high water content, indicating that there is great potential in deacidification of acidic oil catalyzed by SMS with the assistance of calcined kaolin for biodiesel production.

Deep eutectic solvent (DES) assisted deacidification of acidic oil and retaining catalyst activity: Variables optimization and catalyst characterization

Deacidification is a critical step in alkali catalyzed transestrification of acidic oil for biodiesel production. In this work, optimization of the process variables and insights into the mechanisms of deep eutectic solvent (DES) assistance of deacidification of acidic oil catalyzed by Amberlyst 15 were investigated. Specifically, response surface methodology (RSM) and Box-Behnken Design (BBD) were employed to optimize the three process variables, namely temperature, catalysis loading, and molar ratio of methanol to oleic acid. Furthermore, the catalysts before and after used with and without DES assistance were characterized by FTIR and XRD in order to elucidate the chemical mechanisms involved in the process. Results showed that maximum deacidification rate (DR) of 98.02% was achieved in the deacidification process assisted by DES at the optimal process conditions (temperature 72.02ºC, catalyst loading 5.05 wt%, and methanol to oleic acid molar ratio 33.02), compared to 89.68% of the control (without DES assistance). Data analysis and verification results further confirmed the suitability of BBD and RSM methods in optimizing the process. More interestingly, dramatic higher catalytic activity (DR of 76.33% vs 64.16%) of Amberlyst 15 with DES assistance compared to that of the control after 4 cycles was observed. Finally, FTIR spectra confirmed that less water absorbed onto the surface of Amberlyst 15 with DES assistance was the major reason for higher DR and better catalyst reusability in comparison with the control.

An Efficient Deacidification Process for Safflower Seed Oil with High Nutritional Property through Optimized Ultrasonic-Assisted Technology.

Safflower seed oil (SSO) is considered to be an excellent edible oil since it contains abundant essential unsaturated fatty acids and lipid concomitants. However, the traditional alkali-refined deacidification process of SSO results in a serious loss of bioactive components of the oil and also yields massive amounts of wastewater. In this study, SSO was first extracted by ultrasonic-assisted ethanol extraction (UAEE), and the extraction process was optimized using random centroid optimization. By exploring the effects of ethanol concentration, solid–liquid ratio, ultrasonic time, and the number of deacidification times, the optimum conditions for the deacidification of safflower seed oil were obtained as follows: ethanol concentration 100%, solid–liquid ratio 1:4, ultrasonic time 29 min, and number of deacidification cycles (×2). The deacidification rate was 97.13% ± 0.70%, better than alkali-refining (72.16% ± 0.13%). The values of acid, peroxide, anisidine and total oxidation of UAEE-deacidified SSO were significantly lower than those of alkali-deacidified SSO (p < 0.05). The contents of the main lipid concomitants such as tocopherols, polyphenols, and phytosterols in UAEE-decidified SSO were significantly higher than those of the latter (p < 0.05). For instance, the DPPH radical scavenging capacity of UAEE-processed SSO was significantly higher than that of alkali refining (p < 0.05). The Pearson bivariate correlation analysis before and after the deacidification process demonstrated that the three main lipid concomitants in SSO were negatively correlated with the index of peroxide, anisidine, and total oxidation values. The purpose of this study was to provide an alternative method for the deacidification of SSO that can effectively remove free fatty acids while maintaining the nutritional characteristics, physicochemical properties, and antioxidant capacity of SSO.

Deacidification of Cranberry Juice Reduces Its Antibacterial Properties against Oral Streptococci but Preserves Barrier Function and Attenuates the Inflammatory Response of Oral Epithelial Cells.

Cranberry (Vaccinium macrocarpon) may be a potent natural adjuvant for the prevention of oral diseases due to its anti-adherence, anti-cariogenic, and anti-inflammatory properties. However, the high titrable acidity of cranberry juice (CJ) has been reported to cause gastrointestinal discomfort, leading consumers to restrict their intake of this beverage. Electrodialysis with a bipolar membrane (EDBM) can reduce the organic acid content of CJ while retaining the flavonoids associated with potential health benefits. This study aimed to assess how the deacidification of CJ by EDBM impacts the antibacterial properties of the beverage against cariogenic (Streptococcus mutans, Streptococcus sobrinus) and commensal (Streptococcus gordonii, Streptococcus oralis, Streptococcus salivarius) streptococci, and how it affects oral epithelial barrier function and inflammatory response in an in vitro model. The removal of organic acids from CJ (deacidification rate ≥42%) reduced the bactericidal activity of the beverage against planktonic S. mutans and S. gordonii after a 15-min exposure, whereas only the viability of S. gordonii was significantly impacted by CJ deacidification rate when the bacteria were embedded in a biofilm. Moreover, conditioning saliva-coated hydroxyapatite with undiluted CJ samples significantly lowered the adherence of S. mutans, S. sobrinus, and S. oralis. With respect to epithelial barrier function, exposure to CJ deacidified at a rate of ≥19% maintained the integrity of a keratinocyte monolayer over the course of 24 h compared to raw CJ, as assessed by the determination of transepithelial electrical resistance (TER) and fluorescein isothiocyanate-conjugated dextran paracellular transport. These results can be in part attributed to the inability of the deacidified CJ to disrupt two tight junction proteins, zonula occludens−1 and occludin, following exposure, unlike raw CJ. Deacidification of CJ impacted the secretion of IL-6, but not of IL-8, by oral epithelial cells. In conclusion, deacidification of CJ appears to provide benefits with respect to the maintenance of oral health.

The effect of acid whey composition on the removal of calcium and lactate during electrodialysis

This study investigated the effect of compositional differences in acid whey from cottage cheese (CAW), quark (QAW), lactose free skyr (LFAW) and normal skyr (NAW) on the rate and extension of deacidification, demineralisation and energy consumption during electrodialysis at 10 V for 180 min. The results showed that the presence of minor amounts of carbohydrates, proteins and salts in acid whey influenced both the removal of lactate and minerals. Under the same processing conditions, 91% of lactate was removed from CAW while only 78% from QAW, which had the highest phosphate concentration. 80% of K+ and 80% of Mg2+ and Ca2+ were removed faster in CAW likely due to the highest whey protein concentration. Furthermore, lower Mg2+ and Ca2+ were removed from whey with high concentrations of sugars (LFAW). The energy consumption was found to be most dependent on conductivity and therefore lowest for CAW and highest for QAW.

Optimization of malolactic fermentation parameters with isolated and characterized lactic acid bacteria associated with grape berries

A total of 21 microorganisms were isolated from grape berries’ of Punjab MACS purple and H-144. Qualitative analysis (growth on YNB media) of the nine bacterial isolates lead to screening of PII and HIII for malic acid deacidification. Quantitative estimation showed that PII isolate (59.0%) had higher malic acid deacidification rate than HIII (49.7%) compared to the standard L. oenos culture that had 67% malic acid deacidification efficiency. Molecular identification indicated that the PII isolate belongs to Lactobacillus sp. having 99% similarity with Lactobacillus plantarum subsp. argentoratensis AJ640078 and 98% similarity with Lactobacillus plantarum CP010528. Post-ethanolic malolactic fermentation by PII at the rate of 7.1% (v/v) inoculum size with 243.2 mg/L YNB supplementation lead to 58.7% and 60.0% deacidification of malic acid to lactic acid in 12 days among grape juice resulting in wine production with desirable malic acid contents. Practical applications The study represents the effect of Malolactic fermentation on grape wines resulting in reduced malic acid content having more smooth and buttery flavor in the final quality wine. Malolactic bacteria isolated from the grape berries itself have a good potential to carry out malolactic fermentation and performs at par with the commercial strains that can be explored and commercialized further for the industrial use.

Study on deacidification process of waste internal combustion engine oil under the action of ultrasound

Internal combustion engine oil must be replaced periodically because it deteriorates during use, owing to the formation of oxidized species, particularly organic acids. The oil can be regenerated by removing the acids through alkali washing and neutralization. However the neutralization forms soaps that can cause significant emulsification that decrease the rate of acid removal. We have found that the washing process can be enhanced by using ultrasound, which produces strong shock waves and cavitation that increase the rates of diffusion and mass transfer, leading to an increased rate of deacidification. Our experiments show that a binary base composed of 58 wt% alum and 1.8 wt% diethylamine works well at a deacidification temperature of 50 °C, ultrasonic power of 800W, deacidification reaction time of 18 min. The extent of deacidification can be as high as 88% at 1.5 h.

Feasibility of using electrodialysis with bipolar membranes to deacidify acid whey

A nonreagent method for the regulation of the pH of acid whey was investigated at a laboratory scale. Acid whey and concentrated acid whey were subjected to electrodialysis with bipolar membranes in order to raise the pH value to 6.5. Demineralised whey underwent identical processing. The deacidification rate as per tonne of a dry matter was similar for acid whey and concentrated acid whey treatment at 70% and 90% degrees of demineralisation. We estimated the energy consumption of electrodialysis. The preliminary demineralisation of whey significantly increased the energy efficiency of whey pH correction. Additionally, we observed substantial fouling on the diluate side of bipolar membranes after whey treatment.

Catalytic Deacidification of Vacuum Gas Oil by ZnO/Al2O3 and Its Modification with Fe2O3

High acidic vacuum gas oil (VGO) decreases product quality and causes corrosions. To overcome these problems, catalytic esterification was utilized for the deacidification of VGO. A series of Al2O3-supported ZnO catalysts, undoped and doped with Fe2O3, were prepared and characterized. The results showed that both the ZnO/Al2O3 and the ZnO/Al2O3 doped with Fe2O3 had good deacidification effects with glycol for the 4th VGO. The deacidification rate reached 95.1% and 97.6%, respectively, under mild conditions (catalysts 2.5 wt%, glycol dosage 4.0 wt%, 250 °C and 1 h). The naphthenic acids were transferred into ester, which was proved by the Fourier Transform Infrared (FT-IR) and 1H nuclear magnetic resonance (NMR).Reusability of the catalyst for the esterification reaction was also studied. It was found that the deacidification rate was still over 90% after six reruns.

Deacidification of diesel using tetramethylammonium hydroxid/ammonia under demulsifier

Acids in diesel bring great harm to storage devices, transportation facilities and engines. Acids in diesel were removed by tetramethylammonium hydroxid (TMAH)/ammonia under nonylphenol ethoxylate as demulsifier. The effect of process parameters on removing acids was reviewed, such as volume ratio of TMAH to ammonia, volume ratio of deacidification agents to diesel, demulsifier dosage, deacidification temperature and deacidification time. The results showed that the optimum deacidification process was that volume ratio of TMAH to ammonia was 10:1, volume ratio of deacidification agents to diesel was 0.7:1, demulsifier dosage was 0.15 mL, deacidification temperature was 293 K and deacidification time was 5 min. Under the optimum process, deacidification rate of reached 88.36%. The deacidification process effectively removed acids in diesel, had a little effect on other physicochemical properties of diesel, moreover, the color of treated diesel also was greatly improved.

Enhanced deacidification of acidic oil catalyzed by sulfonated granular activated carbon using microwave irradiation for biodiesel production

Deacidification is a dispensable procedure prior to alkali catalyzed transestrification of acidic oil for biodiesel production. In this study, effect of microwave irradiation on sulfonated granular activated carbon (SGAC) catalyzed deacidification of acidic oil was evaluated. Process variables of deacidification were optimized using response surface methodology (RSM). Results showed that microwave irradiation could enhance deacidification efficiency in comparison with conventional heating and a significant mathematical model was obtained to predict deacidification rate of acidified oil catalyzed by SGAC under microwave heating. Optimum process variables were achieved according to the mathematical model, they were reaction temperature 65 °C, methanol to oil ration 2 (wt/wt), and catalyst loading 5.0% (wt% oil mass). Finally, the optimum process variables were confirmed by experiments, in which average deacidification rate of 93.26% was obtained.

Deacidification and ethyl biodiesel production from acid soybean oil using a strong anion exchange resin

The objective of this work was to investigate simultaneously the deacidification and the ethyl biodiesel production from soybean oil using the Amberlyst A26 OH anion exchange resin. The behavior of the process was investigated as a function of resin loading, ethanol concentration and initial free fatty acids (FFAs) content. To obtain the acidified oil, degummed soybean oil and commercial linoleic acid were mixed. The Langmuir model was able to better describe the FFAs adsorption isotherms in comparison to the Freundlich equation. A high removal of FFAs with high deacidification rate could be obtained using lower initial ratios of FFAs per mass of dry resin, being this the more favorable condition for oil deacidification. Ester formation showed to be affected by the resin loading, initial FFA content and ethanol concentration in the medium. The adsorption of FFAs seemed to deactivate the catalytic activity of the resin sites. For this reason, a high resin loading was required, although it was still possible to obtain a satisfactory biodiesel production. The present work makes possible deeper understanding of oil processing by anion exchange resins in the presence of an alcoholic solvent.

Research on the Synthesis of Ionic Liquids/Layered Double Hydroxides Intercalation Composites and Their Application on the Removal of Naphthenic Acid from Oil

Three kinds of imidazolium ionic liquids were synthesized, and [Bmim][CH3COO] was selected as a result of its higher deacidification rate at a lower cost. Then, the synthetic ionic liquid was immobilized by layered double hydroxides, and the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), electrospray ionization mass spectrometry (ESI–MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and N2 adsorption–desorption isotherms. The results showed that [Bmim][CH3COO] synthesized by the intercalation method exhibited a better deacidification property compared to the dipping method. When [Bmim][CH3COO]/Mg0.5Ca2.5Al1 (I) synthesized by the intercalation method was used as a reagent, the deacidification rate reached 97.61%. The optimum reaction conditions were at the reagent/oil mass ratio of 0.08, the reaction temperature of 313 K, and th...

Optimization of cranberry juice deacidification by electrodialysis with bipolar membrane: Impact of pulsed electric field conditions

Abstract Cranberry is well recognized for its beneficial effects on human health, but consumption of cranberry juice is limited due to its high acidity (high organic acid content) which is the cause of undesirable side effects such as diarrhea, vomiting and bloating. Therefore, the acidity could be reduced to improve the palatability of the juice and to decrease these side effects. Deacidification of juices by conventional electrodialysis and by electrodialysis with bipolar membranes (EDBM) using direct current (DC) has been shown to be very effective in comparison with chemical methods, such as calcium salt precipitation or ion-exchange resin. Therefore, the aim of this study was to evaluate the impact of applying a pulsed electric field (PEF) during EDBM on cranberry juice deacidification and electrodialytic parameters. The PEF procedure consists of introducing an electric pulse and a pause consecutively for a given time. PEF has numerous advantages such as reducing fouling and increasing current efficiency. Nine different pulse/pause combinations were tested: 1 s/0.1 s, 1 s/1 s, 2 s/2 s, 6 s/0.1 s, 6 s/1 s, 6 s/2 s, 10 s/0.1 s, 10 s/1 s, and 10 s/2 s. Cranberry juice was deacidified about 15–18% faster using PEFs and the energy consumption decreased by 7–10% for 1 s/1 s and 2 s/2 s conditions in comparison to DC conditions. In both PEF conditions, the migration of citric and malic acid anions was faster, thus leading to an increased rate of deacidification. To the best of our knowledge, this is the first demonstration of the efficiency of using PEF for the deacidification of fruit juice. EDBM under PEF would be a green and sustainable alternative process for deacidifying fruit juice and preserving its organoleptic characteristics.

Deacidification from FCC diesel using 2-methylimidazole and ammonia

ABSTRACTAcids in FCC diesel is harmful to production equipments, storage, and transportation facilities. The complex deacidification process was adopted to remove acid from diesel using 2-methylimidazole and ammonia. The effect of all process parameters on removing acid from diesel was discussed, which included reaction temperature, mass ratio of complex deacidification agents, reaction time, and volume ratio of complex deacidification agents to diesel. Orthogonal experiments were done to optimize deacidification process on the basis of single factor experiments. The results showed that the optimum deacidification process was that volume ratio of complex deacidification agents to diesel was 0.20:1, reaction time was 12 min, mass ratio of 2-methylimidazole to ammonia was 0.4:1 and reaction temperature was 343 K. Under this condition, the deacidification rate reached 96.5%. This deacidification process had little effect on other physical and chemical properties of diesel.

Removal of naphthenic acid from diesel by complex deacidification agents

ABSTRACTNaphthenic acid in diesel was removed by complex deacidification agents consisting of sodium hydroxide and ethanol. The effect of all parameters on removing naphthenic acid from diesel was reviewed systematically. On the basis of single factor experiments, orthogonal experiments were performed to optimize the deacidification process. The results showed that the optimum deacidification process was that the volume ratio of sodium hydroxide to ethanol was 2:1, the volume ratio of complex deacidification agents to diesel was 1.4:1, the reaction temperature was 303 K, the reaction time was 50 s, and the standing time was 30 min. The acidity of the diesel was reduced from 135.52 mg KOH/100 mL to 4.52 mg KOH/100 mL, and the deacidification rate reached 96.66% under the optimum process; thus the treated diesel met the quality requirements.

Deacidification of cranberry juice protects against disruption of in-vitro intestinal cell barrier integrity

Cranberry juice is a well-known functional juice that has many beneficial effects on human health. However, it also has a high concentration of organic acids which may cause gastrointestinal discomfort. Hence, the organic acid content in cranberry juice was reduced to different levels of deacidification (0%, 19%, 37%, 50%, and 77%) by electrodialysis to study the impact of the deacidification rate on intestinal cell integrity. Before in vitro tests on Caco-2 cells, all samples underwent three steps of in vitro digestion: oral, gastric and intestinal. Digested and deacidified cranberry juices were applied to Caco-2 cells and the transepithelial electrical resistance (TEER) was measured after 24 hours of contact to evaluate the resulting cell integrity. In the presence of deacidified cranberry juice, the integrity of caco-2 cell monolayers measured by the ΔTEER was increased by 56% in comparison with raw cranberry juice, but a minimal deacidification rate of 37% was necessary to reach this level of protection.