Extraction of Carboxylic Acids from Aqueous Solutions with the Extractant System Alcohol/Trin‐Alkylamines

A frequent problem in the production of organic compounds via partial oxidation are unwanted byproducts, like acetic acid. Here, the convenient method for working‐up the aqueous acidic effluents (containing up to 10 wt.‐% acid) after removing the main product is the extraction. The influence of various extractant systems containing organic solvents and trialkylamines on distribution coefficients and selectivities of acids has been studied. Acetic acid and lactic acid served as model compounds for acidic byproducts and acidic fermentation products, respectively. Experimental results indicate that combinations of tri‐n‐hexylamine and an alcohol show greatest synergistic effects and as a consequence comparably high distribution coefficients.     

羧酸对铝合金中温阳极氧化的影响

研究了一些常见的羧酸以及硫酸浓度等对铝合金中温阳极氧化膜的厚度和硬度的影响。结果表明：适当降低硫酸浓度,特别是在硫酸溶液中加入适量的某些羧酸,可提高膜的厚度和硬度。其中,碳链短的效果更好。采用该工艺,可将工作温度上限至少提高１１℃。     

稀释剂对三辛胺萃取羧酸的影响

研究了三辛胺萃取羧酸过程的机理,发现该过程中稀释剂的影响十分显著,在不同的稀释剂中三辛胺萃取羧酸的分配比相差三十至七十倍。其萃取能力与三辛胺的浓度和稀释剂的性质有关。萃取剂浓度一定时,取决于萃合物与稀释剂的相互作用能力及其在稀释剂中的疏溶作用。相互作用能力越强,疏溶作用越弱,越有利于革取。     

Extraction of Benzene and Naphthalene Carboxylic Acids Using Quaternary Ammonium Salts As a Model Study for the Separation of Coal Oxidation Products

Abstract

The ion‐pair solvent extraction of benzene‐ and naphthalene‐carboxylic acids has been investigated as a model study for the separation of coal oxidation products, which are formed by treatment with alkaline solutions at high temperatures. It was possible that benzene‐ and naphthalene‐dicarboxylic acids are extracted into several types of organic solvents with quaternary ammonium ions. The extraction equilibrium constants (K_ex) for benzoic acid, 1,2‐benzenedicarboxylic acid, 1,3‐benzenedicarboxylic acid, 1‐naphthoic acid, 2‐naphthoic acid, 2,3‐naphthalenedicarboxylic acid, and 2,6‐naphthalenedicarboxylic acid into chloroform were determined at 20°C. The difference of K_ex among the aromatic acids was sufficiently large for designing a separation method for these aromatic acids. It was unexpected that the extraction of dicarboxylic acids was slower than that of monocarboxylic acids, although the ion‐pair formation of aromatic carboxylate ion with quaternary ammonium ion is normally considered as a diffusion control reaction in aqueous phase. Thus, this fact suggests that the phase transfer of the ion‐pair from aqueous to organic phase is the rate‐determining step. Liner‐free‐energy relationship was observed for the monocarboxylic acids using different quaternary ammonium salts while that was ambiguous for the dicarboxylic acids. This is due to the steric influence of the counter ions for the magnitude of K_ex.     

腐植酸对叔胺萃取铀的影响

简要叙述了腐植酸的主要性能,论述了腐植酸对叔胺-煤油溶液萃取铀和反萃取铀过程的影响。腐植酸与腐植酸铀酰盐对叔胺-煤油溶液萃取铀将降低萃取效率,并形成乳化。在反萃取铀过程中,实践表明,采用腐植酸脱除剂Na2CO3作为反萃取剂进行反萃取,可以有效把叔胺-煤油溶液中负载的铀、腐植酸铀酰盐以及腐植酸反萃取下来,铀的反萃取率达98%以上,腐植酸的脱除率达99%以上;且两相之间无乳化膜。     

Fatty Imidazolines: A Novel Extractant for the Recovery of Palladium(II) from Hydrochloric Acid Solutions

The extraction of palladium(II) from hydrochloric acid solutions with a novel highly basic extractant, a mixture of homologous 1-[2-(alkanoylamino)ethyl]-2-alkyl-2-imidazolines (AAI) in toluene with 15% (v/v) of n-octanol was studied. Palladium(II) is rapidly and most effectively extracted with AAI hydrochloride at the low hydrochloric acid (chloride ions) concentration (up to 1 M) and can be completely separated from Fe(III), Cu(II), and Co(II). The palladium(II) extraction at the optimum acidity occurs via an anion-exchange mechanism with the formation of ionic associates (LH)₂PdCl₄ (K _ex = (1.5 ± 0.2) · 10⁴ at 0.5 M HCl) and is accompanied by the dimerization of palladium(II) in the organic phase with the formation of ionic associates (LH)₂Pd₂Cl₆ (K _dim = (3.9 ± 0.4) · 10^?4 at 0.5 M HCl). The anion-exchange extraction of palladium(II) at the acidity of 0.5 M HCl is temperature independent in the range 20–49°C. Complete stripping of palladium(II) can be performed using a 5% solution of thiourea in 0.1 M HCl.     

The Effect of Evaporator Temperature on Lactic Acid Purity and Recovery by Short Path Evaporation

In this work, the evaluation of lactic acid concentration from a synthetic mixture of water and lactic acid (3 wt% of lactic acid) was carried out using short path evaporation (SPE). The evaporator temperature of a SPE is one of the important technological parameters that determine an evaporator’s operation. In this study, the effect of the evaporator temperature on the lactic acid purity and recovery was observed from 303 to 443 K. The results showed that, in the studied range, the evaporator temperature of 353 K can be regarded as the best, since an increase of 2.15 times in the solution concentration was obtained.     

温度对用N,N-二(1-甲基庚基)乙酰胺萃取剂处理含酚废水效果的影响

采用N，N－二（1－甲基庚基）乙酰胺萃取剂，离心萃取处理酚醛树脂含酚废水，废水温度对萃取效率影响显著，适宜水温为20－35℃。     

The cytotoxicity of fatty acid/α‐lactalbumin complexes depends on the amount and type of fatty acid

Complexes of the milk protein, α‐lactalbumin, and the fatty acid, oleic acid, have previously been shown to be cytotoxic. Complexes of α‐lactalbumin and five different fatty acids (vaccenic, linoleic, palmitoleic, stearic, and elaidic acid) were prepared and compared to those formed with oleic acid. All complexes were cytotoxic to human promyelocytic leukemia‐derived (HL‐60) cells but to different degrees depending on the fatty acid. The amount of fatty acid per α‐lactalbumin molecule was found to correlate with the cytotoxicity; the higher the number of fatty acids per protein, the more cytotoxic the complex. Importantly, all the tested fatty acids were also found to be cytotoxic on their own in a concentration dependent manner. The cytotoxic effect of complexes between α‐lactalbumin and linoleic acid, vaccenic acid, or oleic acid was further investigated using flow cytometry and found to induce cell death resembling apoptosis on Jurkat cells. Practical applications: Cytotoxic complexes of α‐lactalbumin and several different fatty acids could be produced. The cytotoxicity of all the variants is similar to that previously determined for α‐lactalbumin/oleic acid complexes.     

Effect of Solvent,Preheating Temperature,and Time on the Ultrasonic Extraction of Phenolic Compounds from Cold‐Pressed Hempseed Cake

The effect of different solvents (aqueous methanol [70%, v/v], aqueous acetone [80%, v/v], and a solvent mixture [MA] of aqueous methanol [70%, v/v] and aqueous acetone [70%, v/v] in a ratio of 1:1 [v/v]), preheating temperatures (140, 160, and 180°C), and times of exposure (5, 15, and 30 min) on the ultrasonic extraction of the main phenolic compounds from hempseed cake (Cannabis sativa) was investigated. A simplified new high‐performance liquid chromatography (HPLC) method was developed to identify and quantify the main phenolics (namely, N‐trans‐caffeoyltyramine and cannabisin B) in the extracts. Two other main compounds, numbered 3 and 4 , were also detected. The results showed that the nature of the extracting solvent had a significant (P < 0.05) impact on the ultrasonic extraction of phenolic compounds. The acetone extracts exhibited the highest total phenolic content (TPC), followed by MA and methanol. The preheating temperature and time of exposure enhanced the TPC for all solvents examined. The main phenolics, N‐trans‐caffeoyltyramine, cannabisin B, and compound 3 , were positively affected by the temperature and time of exposure, irrespective of the solvents used. In sharp contrast, compound 4 appeared to be thermally sensitive: increasing preheating time and temperature decreased the yields of this compound. This study demonstrated that acetone was the most effective extracting solvent and that preheating enhanced the yield of the main phenolics.     

Studies on the Separation and Recovery of Plutonium from Nitric Acid Medium using Di-nonyl Phenyl Phosphoric Acid (DNPPA) / n-Dodecane as Extractant System

This paper deals with the studies on the separation and recovery of plutonium from nitric acid medium using Di-nonyl phenyl phosphoric acid (DNPPA) in n-paraffin as an extractant system. The different extraction parameters were investigated. The percentage extraction of plutonium decreased with increase in nitric acid concentration. The optimum solvent concentration for quantitative separation of plutonium from aqueous feed solution was 0.15 M of DNPPA whereas n-paraffin/n-dodecane was the most suitable of diluents with an organic to aqueous phase ratio of 1:1. Among the various strippants used, 0.5 M solution of (NH₄)₂CO₃ was found to be the most suitable for back extraction of plutonium from the loaded organic phase. The developed method was used to separate and recover plutonium from actual wash solution of ion exchange column used for plutonium purification. More than 73% of plutonium was separated from 7 M HNO₃ wash solution using 0.15M of DNPPA in n-dodecane.     

Effect of the Drying Process on the Intensification of Phenolic Compounds Recovery from Grape Pomace Using Accelerated Solvent Extraction

In light of their environmental and economic interests, food byproducts have been increasingly exploited and valorized for their richness in dietary fibers and antioxidants. Phenolic compounds are antioxidant bioactive molecules highly present in grape byproducts. Herein, the accelerated solvent extraction (ASE) of phenolic compounds from wet and dried grape pomace, at 45 °C, was conducted and the highest phenolic compounds yield (PCY) for wet (16.2 g GAE/100 g DM) and dry (7.28 g GAE/100 g DM) grape pomace extracts were obtained with 70% ethanol/water solvent at 140 °C. The PCY obtained from wet pomace was up to two times better compared to the dry byproduct and up to 15 times better compared to the same food matrices treated with conventional methods. With regard to Resveratrol, the corresponding dry pomace extract had a better free radical scavenging activity (49.12%) than the wet extract (39.8%). The drying pretreatment process seems to ameliorate the antiradical activity, especially when the extraction by ASE is performed at temperatures above 100 °C. HPLC-DAD analysis showed that the diversity of the flavonoid and the non-flavonoid compounds found in the extracts was seriously affected by the extraction temperature and the pretreatment of the raw material. This diversity seems to play a key role in the scavenging activity demonstrated by the extracts. Our results emphasize on ASE usage as a promising method for the preparation of highly concentrated and bioactive phenolic extracts that could be used in several industrial applications.     

离心萃取器提取对甲酚的实验和模拟研究

In this study, extraction of p-cresol from the simulated wastewater has been studied using centrifugal extractors and QH-1 extractant. The distribution ratio of p-cresol was approximately 308.5 in the QH-1-p-cresol （pH =2.0） system. The extraction stage efficiency of the single-stage centrifugal extractor was higher than 92%, and the extraction rate of the three-stage cascade was higher than 99%. When 15% NaOH was used for the stripping of p-cresol in QH-1 solution, the stripping rate of the three-stage cascade reached 100%. A mathematical model of multistage countercurrent extraction process that considers the phase volume change, extraction stage efficiency, and phase entrainment was used to simulate the extraction of p-cresol using centrifugal extractors. The calculated results using this model were in good agreement with the experimental results.     

温度调控对氧化聚乙烯工业生产的影响

通过对氧化聚乙烯反应过程的温度灵敏性研究发现:通过程序控制反应温度的方法,将反应过程控制在一个较小的温度区间内进行,可以得到更加优质的产品。通过温度调控后产品的酸值及白度测试分析可以发现:激发温度在140～150℃,反应温度在135～140℃反应效果最好,可以得到最优质的产品。     

Effect of Binary/Ternary Fatty Acids Ratio and Glycerin on the Phase Behaviors of Soap Solutions

Phase behaviors of liquid soaps prepared with single myristic acid, binary fatty acid mixtures and ternary fatty acid mixtures (with 30% total fatty acids) are described. The influence of glycerin on the phase behaviors of ternary soaps is discussed. Phase behaviors were characterized by combining pH, viscosity, polarization microscopy, X‐ray scattering and differential scanning calorimetry (DSC) analysis. The results showed that the kind and proportion of fatty acids played key roles in the phase behaviors of soaps. Glycerin had a significant influence on the phase behaviors of soaps. Liquid and Cub + Hex (cubic and hexagonal phase) phase were stable, while Liq + Crystal (liquid micelle and crystal phase), Liq + Lam (liquid micelle and lamellar phase), Liq + Hex + Lam (liquid micelle and hexagonal and lamellar phase) phases displayed separation regions, Glycerin was investigated to improve the stability of separation phases for two weeks, appropriate percentage of the fatty acids in soaps application.     

温度对HDPE/MPA共混物阻透性能的影响

分析了溶剂分子透过聚合物共混物的溶解-扩散行为,建立了溶剂分子扩散通量与其表观扩散活化能、偏摩尔混合焓以及温度之间的关系式。并采用多种配方的HDPE/MPA共混物,在不同温度下进行渗透实验,结果表明本文建立的关系式与实验数据吻合良好。     

The Influence of Fatty Acids on the GpA Dimer Interface by Coarse-Grained Molecular Dynamics Simulation

The hydrophobic thickness of membranes, which is manly defined by fatty acids, influences the packing of transmembrane domains of proteins and thus can modulate the activity of these proteins. We analyzed the dynamics of the dimerization of Glycophorin A (GpA) by molecular dynamics simulations to describe the fatty acid dependence of the transmembrane region assembly. GpA represents a well-established model for dimerization of single transmembrane helices containing a GxxxG motif in vitro and in silico. We performed simulations of the dynamics of the NMR-derived dimer as well as self-assembly simulations of monomers in membranes composed of different fatty acid chains and monitored the formed interfaces and their transitions. The observed dimeric interfaces, which also include the one known from NMR, are highly dynamic and converted into each other. The frequency of interface formation and the preferred transitions between interfaces similar to the interface observed by NMR analysis strongly depend on the fatty acid used to build the membrane. Molecular dynamic simulations after adaptation of the helix topology parameters to better represent NMR derived structures of single transmembrane helices yielded an enhanced occurrence of the interface determined by NMR in molecular dynamics simulations. Taken together we give insights into the influence of fatty acids and helix conformation on the dynamics of the transmembrane domain of GpA.     

K2O对MnOx/TiO2低温脱硝催化剂的中毒作用研究

实验通过溶胶-凝胶法制备了MnOx/TiO2脱硝催化剂,以KNO3作为K2O的前驱物模拟催化剂钾中毒,通过SEM,XRD,BET,XPS,NH3-TPD,DRIFTS方法对催化剂微观结构及性能进行表征.在SCR活性试验仪上研究不同含量的K2O对催化剂脱硝活性的影响,结果发现:K2O对于催化剂的毒性较强,随着添加量的增大,催化剂脱硝活性急剧下降,比表面积和孔容逐渐下降.NH3-TPD及DRIFTS结果表明K2O中毒后催化剂表面酸量大大减少,主要原因是K2O的K+与催化剂的活性酸性位结合从而阻碍了NH3在催化剂上的吸附,导致催化剂脱硝率大大下降.     

用KF/Al2O3催化合成肉桂酸的研究

采用KF/Al2O3催化剂催化合成肉桂酸.用新催化剂催化反应可以降低反应温度,缩短反应时间,提高肉桂酸的产率.探索出了最佳反应条件当反应温度控制在160℃,苯甲醛和乙酸酐的摩尔比1∶3,用6.0 g KF/Al2O3催化反应1.0 h,得到肉桂酸的产率为85.4%.