Mixture Of HCl Research Articles

Core/Shell Systems for Delayed Delivery of Concentrated Mineral Acid

Summary Acid stimulation, for both oil and gas wells, greatly supports the industry as a versatile means of enhancing production. Although acids enhance carbonate reservoir permeability to hydrocarbons, the reaction rates of the acid [e.g., hydrochloric acid (HCl)] with the rock often are too rapid at high temperatures, leading to a reduction in acid penetration. Several methods exist to improve the effectiveness of acidizing in high-temperature reservoirs (e.g., greater than 120°C), including the use of conventional emulsified-acid systems, mixtures of HCl and organic acids, and gelled acids. Many of the aforementioned techniques are effective forms of treatment; however, they hold significant limitations such as reduction in acid efficiency, poor control over penetration depth, and the requirement of corrosion inhibitors. Accordingly, encapsulated HCl holds potential as an attractive alternative to address these shortcomings because its prolonged release profile would permit transport of acid deep within the reservoir. In addition, when successfully encapsulated, this technology could eliminate, or at the very least minimize, the use of corrosion inhibitors. Herein, we demonstrate the design and preparation of highly modular core/shell particles comprising concentrated HCl encapsulated within an acrylate-based thermoset polymer shell. We show that the shell-generation mechanism (i.e., photopolymerization of acrylate monomers) is compatible with concentrated HCl and further detail the encapsulation process. Our results demonstrate that the acid-release profiles are dictated by the properties of the shell material, enabling a prolonged delivery of HCl in laboratory studies. This is a first step toward the design of particle-shell systems that can tolerate harsh reservoir conditions, including high temperatures, pressures, and salinity of mixing water. A tunable core/shell delivery system that encompasses a sufficient amount of strong mineral acid is well-poised to address the unmet need of deeper penetration of HCl into the reservoir, enabling greater stimulation efficiency.

Selectrodialysis and bipolar membrane electrodialysis combination for industrial process brines treatment: Monovalent-divalent ions separation and acid and base production

Chemical industries generate large amounts of wastewater rich in different chemical constituents. Amongst these, salts at high concentrations are of major concern, making necessary the treatment of saline effluents before discharge. Because most of these rejected streams comprise a combination of more than one salt at high concentration, it is reasonable to try to separate and revalorize them to promote circular economy at industry site level. For this reason, ion-exchange membranes based technologies were integrated in this study: selectrodialysis (SED) and electrodialysis with bipolar membranes (EDBM). Different process brines composed by Na2SO4 and NaCl at different concentrations were treated first by SED to separate each salt, and then by EDBM to produce base (NaOH) and acids (HCl and H2SO4) from each salt. The optimum of both electrolyte nature and concentration of the SED stack streams was evaluated. Results indicated that it was possible to separate Cl− and SO42− depending on the anionic membrane, initial electrolytes and concentrations of each stream. Pure NaOH and a mixture of HCl and H2SO4 with different purities could be obtained. Energy consumption evolutions were plotted and an optimal zone work was found where the consumption values were acceptable.

Erectogenic, Antihypertensive, Antidiabetic, Anti-Oxidative Properties and Phenolic Compositions of Almond Fruit (Terminalia catappaL.) Parts (Hull and Drupe) -in vitro

This study was conducted to determine the effects of almond (Terminalia catappa L.) fruit parts (hull and drupe) extracts on key enzymes (arginase, angiotensin-1-converting enzyme, α-amylase and α-glucosidase) relevant to erectile dysfunction, type-2 diabetes and hypertension, assess their antioxidant properties and characterize their phenolic constituents. The hull and drupe extracts were prepared by a mixture of absolute methanol and 1N HCl, evaporated to dryness and used for subsequent analysis. The result revealed that the hull and drupe extracts inhibited arginase, angiotensin-1-converting enzyme, α-amylase and α-glucosidase activities in a dose-dependent manner. Both extracts scavenged radicals, reduced Fe3+ to Fe2+, chelated Fe2+ and inhibited lipid peroxidation in rat penile homogenate in vitro. Chlorogenic acid, ellagic acid and kaempferol were identified as the major phenolic compounds. This study suggests that these fruit parts can be natural sources of erectogenic, antihypertensive antidiabetic and anti-oxidative agents. However, the hull showed better potential than the drupe. Practical Applications The results suggest that Almond (Terminalia catappa L.) fruit parts, including the hull and drupe, have potential applications as functional foods and nutraceuticals for both animal and human nutrition. In addition, the hull and drupe could be useful for therapeutic purposes as erectogenic, antihypertensive, antidiabetic and anti-oxidative agents.

Electrochemical synthesis and optical properties of ultra-fine CdSe nanoparticles

Colloidal solutions (~0.3 mol/L) of CdSe nanoparticles in xylene have been synthesized by the electrochemical method from an acid electrolyte based on HNO3 + HCl (2:1) mixture using extraction into xylene. It has been found that CdSe nanoparticles of small size (2–5 nm) synthesized on the cathode are readily extractable in xylene, whereas nanoparticles of larger size (20–100 nm) remain in the aqueous electrolyte and dissolve in the nitric–hydrochloric acids mixture. An X-ray phase analysis of powders of 2–5 nm CdSe nanoparticles showed them have a mixed cubic/hexagonal crystal structure. It has been found from measurements of absorption and photoluminescence spectra that the CdSe nanoparticles of this structure have a broad photoluminescence band (λ max = 500 nm) at a narrow absorption peak (λ max = 420 nm), which may be due to stacking fault formation in nanoparticles of mixed cubic/hexagonal structure. Using this electrolyte with a xylene surface layer under continuous electrolysis conditions and extraction of 2–5 nm CdSe nanoparticles with a content of up to 0.05 g in 1 cm3 xylene (~0.3 mol/L) was obtained. Such colloidal solution can be used to obtain optical nanocomposites by incorporation CdSe nanoparticles into a liquid–crystalline cadmium caprylate matrix. The spectral characteristics such of composites have been studied by adsorption spectroscopy and fluorescence.

Efficient preparation of high-quality 64Cu for routine use

IntroductionCopper-64 is an attractive radionuclide for positron emission tomography and is emerging as a radiotherapeutic agent. The demand of 64Cu with low metallic impurities has increased because of its wide applications when incorporated with antibodies, peptides, and proteins. In this study, we propose a new separation method to produce high-quality 64Cu using a cation exchange column, as well as an automated separation system suitable for large-scale production. Methods64Cu was produced from an electrodeposited 64Ni target via the 64Ni(p,n)-reaction with a 24MeV HH+ beam at 10eμA (electrical microampere) conducted for 1–3h. The irradiated target was transported to a hot cell and disassembled remotely. 64Cu was separated by a solvent mixture of HCl and acetone on a cation-exchange resin, AG50W-X8. The chemical purity of 64Cu final product was evaluated using ion-chromatography coupled with a UV detector and inductively coupled plasma mass spectroscopy for quality as well as metallic impurities. ResultsWe obtained 64Cu in dried form at a yield of 5.2–13GBq at the end of separation, or 521±12MBq/eμAh as the final product within 2.5h of processing time. The metallic impurities were a satisfactory low level in the order of ppb. Major contaminants of Co and Ni were lower than those samples obtained by a widely accepted separation using an anion-exchange resin. ConclusionUsing a cation-exchange resin and a systematic operation, we successfully reduced the contamination level of the 64Cu product. As a straightforward separation method, which shortened the entire processing time, we obtained a satisfactory amount of high-quality 64Cu available for routine use.

Selective recovery of Fe(III), Pd(II), Pt(IV), Rh(III) and Ce(III) from simulated leach liquors of spent automobile catalyst by solvent extraction and cementation

A hydrometallurical process was developed to recover Fe(III), Pd(II), Pt(IV), Rh(III) and Ce(III) from the leach liquor of spent automobile catalysts. Fe(III) was first separated by extraction with tri-butyl-phosphate (TBP). Extraction of the raffinate with tri-isooctylamine (Alamine 308) led to co-extraction of Pd(II) and Pt(IV). They were separately stripped from the loaded Alamine 308 by using a mixture of HCl and thiourea with different concentration. After the recovery of HCl in the raffinate by extraction with tri-2-ethylhexyl amine (TEHA), Rh(III) was recovered by cementation with zinc metal powder. A process flow sheet with the corresponding McCabe-Thiele plots for extraction and stripping was proposed.

Encapsulation of the elderberry fruit anthocyanins by spray drying

Spray-dried forms of anthocyanins were prepared in a maltodextrin matrix. The anthocyanins were extracted by maceration of elderberry fruits in 0.1 M HCl followed by extract filtration through a paper filter. The extract was partially purified by solid phase extraction in a column filled with styrene-divinylbenzene copolymer beads (Sepabeads SP859/L) or in syringe cartridges with C18 silica (BioChemMack ST, Moscow, RF) followed by re-extraction with aqueous HCl and alcohol mixtures. The procedure of reversed-phase HPLC determination of the extracted anthocyanin type is discussed in comparison to HILIC method in DIOL silica columns. The latter method was shown to be preferable to avoid systematic errors in the anthocyanin type determination. Solidphase extraction in syringe cartridges gave samples with very high anthocyanins concentration (up to 70 g of cyanidin-3-glucoside chloride equivalent). When using the copolymer sorbent, the concentration was somewhat lower: up to 27 g/l. After spray drying red powder samples with anthocyanins content more than 2% were prepared, although freeze drying gave only dark resin. The red color of the samples indicates the space separation of flavylium ions in the solid state by radicals of the maltodextrin background.

Separation and preconcentration of platinum-group metals from spent autocatalysts solutions using a hetero-polymeric S, N-containing sorbent and determination by high-resolution continuum source graphite furnace atomic absorption spectrometry

This paper describes the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for determination of Pt, Pd and Rh after separation and concentration by original in-house developed heterochain polymer S, N-containing sorbent. The methods of sample preparation of spent ceramic-based autocatalysts were considered, two of which were used: autoclave decomposition in mixture of acids HCl:HNO3 (3:1) and high-temperature melting with K2S2O7. Both methods anyway limit the direct determination of analytes by HR CS GFAAS. Using the first method it is an incomplete digestion of spent autocatalysts samples, since the precipitate is Si, and the rhodium metal dissolves with difficulty and partially passes into solution. In contrast to the first method, the second method allow to completely transfer analytes into solution, however, the background signal produced by the chemical composition of the flux, overlaps the analytical zone.It was found, that Pt, Pd and Rh contained in the spent ceramic automotive catalysts could be effectively separated and concentrated by heterochain polymer S, N-containing sorbent, which has high sorption capacity, selectivity and resistant to dilute acids. The chosen HR CS GFAAS analysis conditions enable us to determine Pt, Pd and Rh with good metrological characteristics. The concentrations of Pt, Pd and Rh in two samples of automobile exhaust catalysts were found in range of 0.00015–0.00050; 0.170–0.189; 0.0180–0.0210wt%, respectively. The relative standard deviation obtained by HR CS GFAAS was not more than 5%. Limits of detection by HR CS GFAAS achieved were 6.2·10−6wt% for Pt, 1.8·10−6wt% for Pd, and 3.4·10−6wt% for Rh. Limits of determination achieved by HR CS GFAAS were 1.1·10−5wt% for Pt, 6.9·10−5wt% for Pd, and 8.3·10−5wt% for Rh.To control the accuracy of PGM in sorption concentrates by HR CS GFAAS method, it was appropriate to conduct an inter-method comparative experiment. The researches on the application of atomic-emission spectroscopy method with inductively coupled plasma as a comparative method were conducted. In addition, the trueness control of the obtained results is confirmed by added-found method.

ChemInform Abstract: A One‐Dimensional Polyoxomolybdate Polymer as a Catalyst for the Epoxidation of Olefins.

AbstractThe one‐dimensional coordination polymer {(NH4)4Mo8O26}n is hydrothermally synthesized from an aqueous mixture of (NH4)6Mo7O24, ZnCl2, HCl, and terephthalic acid (autoclave, 140 °C, 4 d).

Effect of sintering conditions on mechanical strength and gas permeability of long porous Inconel 625 tubes for hot gas filtration

The sintering responses of Inconel 625 prealloyed powder (powder size: 80–180 μm accounting for 96 wt-%) were first assessed using dilatometry. Then, sintering of Inconel 625 tubes (Φ54 mm × 1000 mm), shaped by cold isostatic pressing from prealloyed powder at 170 MPa, was studied at temperatures between 1180 and 1260°C in vacuum and hydrogen. Sharp, rapid shrinkage of Inconel 625 prealloyed powder was observed at 1240°C when sintered in vacuum, while this temperature was postponed to 1260°C when sintered in hydrogen due to the cooling effect of the large hydrogen gas flow. It is shown that sintering in hydrogen is better suited to the fabrication of high performance porous Inconel 625 tubes than sintering in vacuum. The preferred isothermal sintering conditions were determined to be sintering in hydrogen at 1240°C for 120 min, which resulted in balanced mechanical strength and gas permeability. The as sintered porous Inconel 625 tubes (Φ54 mm × 1000 mm) have been used to filter hot (up to 400°C) gas mixtures of SiHCl3 and HCl in continuous industrial operations for 6 months and demonstrated outstanding performance.

An in situ derivatization – dispersive liquid–liquid microextraction combined with gas-chromatography – mass spectrometry for determining biogenic amines in home-made fermented alcoholic drinks

A novel dispersive liquid–liquid microextraction (DLLME) gas chromatography mass-spectrometry (GC–MS) method was developed for the determination of 13 biogenic amines in home-made wine samples. The method allows to simultaneous extraction and derivatization of the amines providing a simple and fast mode of extract enrichment. During the study, two different procedures were examined. Statistical analysis was performed to choose better procedure, as well as the conditions of derivatization reaction. At least, a mixture of methanol (dispersive solvent; 215μL), chloroform (extractive solvent; 400μL), and isobutyl choloroformate (derivatizing reagent; 90μL) was used as extractive/derivatizing reagent, added to 5mL of sample. The addition of mixture of pyridine and HCl was necessary to eliminate the by-products. The proposed method showed good linearity (correlation coefficients >0.9961), good recoveries (from 77 to 105%), and good intra-day precision (below 13%) and inter-day precision (below 10%). Moreover, detection limits were never over 4.1μg/L. The developed method was successfully applied to the analysis of 17 home-made wine samples not regulated by law. All of the biogenic amines analyzed were found in most of the wines.

Facile synthesis of pyridinium functionalized anion exchange membranes for diffusion dialysis application

Abstract Pyridinium functionalized anion exchange membranes are prepared for diffusion dialysis using polyvinyl alcohol (PVA) as base material. Four membranes have been prepared by varying the content of pyridinium salt. The ion exchange (IEC), water uptake (WU), thickness and linear expansion ratio have been measured or calculated. These membranes have shown excellent thermal and chemical stabilities. When applied in diffusion dialysis with a simulated solution mixture of HCl and FeCl2, the membranes show successfully good acid recovery and separation factor. The acid dialysis coefficients are in the range of 1.74–2.48 (10−2 m/h) and separation factors in the range of 30.49–57.51. The obtained acid dialysis coefficients and separation factors are greater than that of the widely used commercial membrane DF-120 with (UH = 0.9 × 10−2 m/h) and (S = 18.5). Hence, the results of this study suggest that the pyridinium functionalized AEMs can be potentially applied in diffusion dialysis process for acid recovery.

Combined wet chemical etching and anodic oxidation for obtaining the superhydrophobic meshes with anti-icing performance

The superhydrophobic state of surface of AMG2 aluminum alloy meshes was obtained by wet chemical etching in mixture of HCl and HF, anodic oxidation in phosphoric acid solution, and chemisorption of fluorooxysilane. Testing of fabricated coatings against long term contact with high-octane gasoline and water indicates very high chemical resistance of superhydrophobic coatings. The anti-icing potential of fabricated superhydrophobic meshes with respect to deionized and salt water was estimated by analysing the work of adhesion of supercooled droplets, the adhesion of iced droplets to the superhydrophobic mesh, and the freezing statistics. The detected freezing delay for both deionized and salt water amounts several hours allowing the removal of the droplets before freezing due to their rolloff under wind or vibration loads.

Sorghum stem extract modulates Na+/K+-ATPase, ecto-5′-nucleotidase, and acetylcholinesterase activities

Sorghum stem (Sorghum bicolor) has been in use in traditional medicine systems for the management of neurodegenerative conditions. However, there is dearth of information on the scientific basis for its use in the treatment of such conditions. This study sought to assess the antioxidant activity and effects of phenolic extract from sorghum stem (Sorghum bicolor) on some cholinergic (acetylcholinesterase (AChE)) and purinergic (Na+/K+-ATPase and ecto-5′-nucleotidase) enzymes associated with neurological conditions. Phenolic-rich extract was prepared using methanol: 1 N HCl (1:1, v/v) mixture and characterized using high-performance liquid chromatography-diode array detector (HPLC-DAD). In vitro tests were used to investigate the effects of the phenolic extract on AChE, Na+/K+-ATPase, and ecto-5′-nucleotidase activities. Furthermore, the hydroxyl (OH) radical scavenging and Fe2+-chelating abilities of the extract were investigated. HPLC-DAD analysis revealed the presence of some phenolic acids such as caffeic acid (120.58 mg/g), ferulic acid (76.45 mg/g), gallic acid (17.48 mg/g), chlorogenic acid (16.25 mg/g), and flavonoids such as kaempferol (15.98 mg/g), rutin (51.07 mg/g), quercetin (263.16 mg/g), and quercitrin (89.21 mg/g) in the phenolic extract. The extract significantly inhibited AChE and ecto-5′-nucleotidase activities in a dose dependent manner with IC50 = 24.88 μg/ml and IC50 = 37.49 μg/ml, respectively, and increased Na+/K+-ATPase activity in a dose dependent manner. Furthermore, the phenolic extract also scavenged OH radicals and was able to chelate Fe2+ in a dose dependent manner with IC50 = 54.27 μg/ml and 18.47 μg/ml, respectively. This study revealed the antioxidant and modulatory effects of phenolic extracts from sorghum stem on some cholinergic and purinergic enzymes.

Development and Adsorption Properties for a Novel Lithium Ion-Sieve

The lithium ion-sieve precursor was prepared with LiOH and Mn (CH3COO)2 as the starting reagents, H2O2 as the oxidant and ethanol solution (volume percent 2.5%) as solution by combination of sol-gel, hydrothermal and low-temperature solid state methods, and then changed into lithium ion-sieve after eluting Li+ by the mixture of HCl and Na2S2O8 solution. The influence of synthetic conditions on the structures and adsorption properties of lithium ion-sieve was investigated in detail. The results suggest that the pure phase lithium ion-sieve can be synthesized when Li/Mn molar ratio is 3/1, 3.2mL H2O2 is added after LiOH and Mn (CH3COO)2 react for 36h and the heat treatment way of programmed temperature from 410°C (2h) to 510°C (3h) is adopted in the progress of solid state reaction. The loss rate of dissolved Mn is less than 2.5% during pickling Li+. And the highest adsorption capacity can achieve 20.5mg/g.

Thermoresponsive Wrinkles on Hydrogels for Soft Actuators

Thermoresponsive Wrinkles on Hydrogels for Soft Actuators

Separation of Ir(IV) and Rh(III) from strong hydrochloric acid solutions by solvent extraction with amines

The separation of Ir(IV) and Rh(III) from chloride solution by extraction with amines (TOA, TEHA, Alamine 308, and Aliquat 336) was investigated. Ir(IV) was selectively extracted over Rh(III) by these extractants. HCl concentration affected little the extraction of metals. The highest separation factor of 82.5 between the two metals was obtained from 1M HCl solution by extraction with Aliquat 336. Solution aging until 2 weeks depressed the extraction of Rh(III). The mixture of HCl and thiourea stripped Ir(IV) selectively from the loaded amines and thus promoted the separation.

Derivative Quotient Spectrophotometry and an Eco-Friendly Micellar Chromatographic Approach with Time-Programmed UV-Detection for the Separation of Two Fluoroquinolones and Phenazopyridine.

In this study, two analytical approaches were exploited for the resolution of binary mixtures of ciprofloxacin HCl (CIP) or norfloxacin (NOR) and phenazopyridine HCl (PHZ). In the first approach, the amplitudes of the first derivative of the ratio spectra were measured at 267 or 287 nm for CIP and at 268 or 291 nm for NOR. PHZ could be directly determined in the presence of CIP or NOR at 405 nm. The calibration graphs were rectilinear over the ranges of 1.0-16.0 µg/mL for CIP or NOR and 1.0-10.0 µg/mL for PHZ. In the second approach, an accurate, reliable and environmentally nontoxic micellar liquid chromatographic (MLC) method was developed. A good chromatographic separation was achieved using a 150 mm × 4.6 mm i.d., 5 µm particle size Spherisorb ODS-2 column. Eco-friendly mobile phase containing 0.12 M sodium dodecyl sulphate, 0.3% triethylamine and 6%n-butanol in 0.02 M orthophosphoric acid of pH 3.0 was pumped at a flow rate of 1 mL/min. Time programmed UV-detection was applied to allow sensitive determination of the studied drugs. The analytes were eluted without interferences in <10 min. Methocarbamol was used as an internal standard. The MLC method was found to be rectilinear over the concentration range of 0.5-20.0 μg/mL for CIP, NOR or PHZ. These optimized and validated methods were successfully applied for the simultaneous analysis of the studied drugs in their synthetic mixtures and co-formulated tablets. Moreover, the second method was further extended to the determination of these drugs in human urine with direct injection and without any pretreatment.

Influence of Anodization Time and Voltage on the Parameters of TiO2 Nanotubes

A vertically aligned titania nanotube layer was obtained by electrochemical anodic oxidation in the electrolyte contained 0.4 wt% solution of NH4F in 54 ml of ethylene glycol and 5 ml of deionized water, after titanium was chemically cleaned/etched with a mixture of HCl, H2O and HNO3 solution for removing the natural oxide films. The morphology and composition of the titania nanotube layer were examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The anodization of TiO2 nanotubes was done using 60 V for 240 min and 30 min, and 30 V for 30 min. The diameter of the titania nanotubes was about 52-156 nm, the wall thickness about 32-53 nm and the height about 0.9-6.3 μm. The pore size of TiO2 nanotubes influences the dissolution rate of CaP thin films and Young's modulus, which is significantly lower than that of the Ti substrate. Our future challenge will be investigation of the microstructure and mechanical behavior of titania nanotubes with CaP film.

Effects of pH on the rates of lipid oxidation in oil–water system

The effect of pH on the oxidative stability in oil–water systems was determined at 40 °C for 18 days by monitoring headspace oxygen depletion and concentration of conjugated dienoic acids (CDAs). Two types of pH solutions were prepared: a buffer solution and a mixture of NaOH and HCl. When the pH of the mixture of NaOH and HCl increased from 1 to 13, the oxidative stability in oil decreased significantly in the order of pH 1 > 10 > 7 > 4 > 13. In case of the buffer solution, the oxidative stabilities of oils were in the order of pH 4 = 7 > 10. Depending on the pH and buffering capacities, oxidative stability of oils were greatly influenced.