Mixture Of Sodium Carbonate Research Articles

High-pressure CO2 permeation properties and stability of ceramic-carbonate dual-phase membranes

CO 2 permeation properties and stability of ceramic-carbonate dual-phase membranes at high pressures/temperatures are critical to their CO 2 separation and membrane reactor applications, but such data are not available in the literature. This work aims to study the effect of high transmembrane pressure on CO 2 permeation flux and the stability of molten carbonate in the dual-phase samarium-doped ceria (SDC) and molten-carbonate (MC) membranes. Dead-end porous SDC tubular supports were made by a cold isostatic press (CIP)/sintering method with a low porosity (below 7%), and gas-tight SDC-MC membranes were prepared by direct infiltration of molten lithium and sodium carbonate mixture into SDC pores, with a MC volume fraction less than 7%. CO 2 permeation/separation tests were performed on the SDC-MC membranes using feed gas of equal molar CO 2 /N 2 mixture at feed pressures up to 15 atm and sweep gas of helium at 1 atm. CO 2 permeation flux for the SDC-MC membranes depends logarithmically on feed/permeate CO 2 pressure ratio in 660–810 o C. The temperature dependence of CO 2 permeation shows activation energy of 30 kJ/mol. Due to the small MC volume fraction and hence low effective carbonate conductivity, CO 2 permeation of the SDC-MC membranes is dominated by the carbonate ionic conduction in the MC phase. The SDC-MC membranes remain in the same structure, morphology, and gas-tightness after CO 2 separation tests at high feed pressures and temperatures, showing high stability of SDC-MC membranes for high-temperature, high-pressure separation and chemical reaction applications. • Strong ceramic-carbonate dual-phase membranes can be made by the cold isostatic press method. • High-pressure CO 2 permeation flux depends logarithmically on feed/permeate CO 2 partial pressure ratio controlled by carbonate ionic conduction. • Samarium-doped ceria-molten carbonates membranes are stable at high pressures/high temperatures.

A Sensitive Microextraction Method Using Effervescence Tablets to Disperse Fe3O4 Nanoparticles for Cadmium Determination in Lake Water Samples

AbstractIn this study, an effective and sensitive method was developed for the preconcentration of cadmium in flame atomic absorption spectrometer system combined with a 5‐holes cut slotted quartz tube (SQT‐FAAS). For this aim, a dispersive solid‐phase microextraction method based on a magnetic effervescent tablet consisting of Fe3O4 nanoparticles (EA‐MNP‐dSPME) was proposed. In the developed microextraction method, the dispersion of the nanoparticles used as adsorbents was assisted by the effervescent tablets generated from a mixture of sodium carbonate and sodium dihydrogen phosphate dihydrate. In order to obtain the highest extraction and instrumental output, all variables that affect the efficiency was investigated comprehensively and optimum conditions were determined with univariate optimization steps. The detection power of the conventional FAAS system was enhanced about 135 folds with respect to the LOD value of the developed method (0.34 ng mL−1) obtained under the optimum conditions. The EA‐MNP‐dSPME method presented high reproducibility with a low %RSD value calculated as 8.1 %. In order to validate the accuracy and applicability of the method, matrix matching method based recovery studies were carried out using the lake water samples taken from Horseshoe Island. The percent recovery results reported between 99.9–104.3 % with percent relative standard deviation below 7.9 % indicated the developed method‘s applicability for the accurate and precise determination of cadmium.

High temperature X-ray diffraction study of the formation of Na2Ti3O7 from a mixture of sodium carbonate and titanium oxide

Na2Ti3O7 has attracted much attention in the field of anode materials for Na-ion batteries thanks to its non-toxicity and very low working potential of 0.3 V vs Na0/Na+. Building a clearer picture of its formation from cheap Na2CO3 and TiO2 starting materials is therefore of obvious interest. Here, we report new insights from an in-situ high temperature X-ray diffraction study conducted from room temperature to 800 °C, complemented by ex-situ characterizations. We were thereby able to position the previously reported Na4Ti5O12 and Na2Ti6O13 intermediate phases in a reaction scheme involving three successive steps and temperature ranges. Shifts and/or broadening of a subset of the Na2Ti6O13 reflections suggested a combination of intra-layer disorder with the well-established ordering of successive layers. This in-situ study was carried out on reproducible mixtures of Na2CO3 and TiO2 in 1:3 molar ratio prepared by spray-drying of mixed aqueous suspensions. Single-phase Na2Ti3O7 was obtained after only 8 h at 800 °C in air, instead of a minimum of 20 h for a conventional solid-state route using the same precursors. Microstructure analysis revealed ~ 15 µm diameter granules made up from rectangular rods of a few-µm length presenting electrochemical properties in line with expectations. In the absence of grinding or formation of intimate composites with conductive carbon, the specific capacity of 137 mAh/g at C/5 decreased at higher rates.

Technological studies of the use of modifiers in the flotation of calcium-containing minerals

Using samples of skarn scheelite-sulfide ore from the Vostok-2 deposit, studies were carried out to model combinations of increased dose of inorganic modifiers (sodium carbonate, water glass, sodium sulfide) based on publications by foreign researchers on the achieved positive result in increasing the contrast of the mineral surfaces of scheelite and calcite and their floatability. Testing was carried out according to the standard flowsheet on tap and recycled water. Oxyhydryl collector was sodium oleate of technical acid B-115, dose 250 + 50 g/t. The order of feeding modifiers (sequential supply and combination of a mixture of sodium carbonate (bicarbonate) + water glass), the effect of the temperature of the pulp upon contact, the dose of modifiers and the ratio of components in the mixture were studied. The dose of water glass varied from 350 to 1450 g/t, sodium carbonate (bicarbonate) varied from 0 to 11.5 kg/t, sodium sulfide up to 4.9 kg / t. With increased dose of inorganic modifiers, it was not possible to achieve selective depression of calcite and apatite while maintaining effective scheelite flotation. The use of sodium bicarbonate in comparison with sodium carbonate, at the same flow rates, creates a less alkaline pH in the flotation pulp, which leads to an increase in the concentration of hardness ions [Са2+, Mg2+] and overdose of the collector. Using combinations of reagents: sodium carbonate (bicarbonate) + water glass, sodium sulfide + sodium hydroxide + water glass, even with a slight increase in the dose of water glass in the mixture, after heat treatment, concentrates of lower quality were obtained, with increased losses of scheelite compared to the factory mode according to the Petrov method.

Treatment of Daqing oily sludge by thermochemical cleaning method

The thermochemical cleaning method was used to treat the oily sludge produced from Daqing oilfield. Cleaning agents were screened innovatively by using interfacial tension (IFT) method. The mixture of sodium carbonate, fatty alcohol ethoxylate (AEO-9), and rhamnolipid with a ratio of 5:1:0.5 was found that had the lowest IFT. They were selected as the cleaning agents and when their mass fraction was 2 wt%, cleaning agents aqeous solution/sludge ratio was 3:1, cleaning time was 40 min and cleaning temperature was 50 °C, the oil content contained by solids after cleaning was reduced to less than 1 wt %, meeting the environmental protection requirement in China. In addition, the simulated adsorption experiment and the characterization of residue on the cleaned solids were done to provide insight into the cleaning process. The results revealed that the oil adsorbed onto the solids (clinoptilolite) mainly by the multilayer physisorption, most of them can be easily removed by the emulsification of cleaning agents, and the residue is mainly asphaltene.

Combination of in situ metathesis reaction with a novel "magnetic effervescent tablet-assisted ionic liquid dispersive microextraction" for the determination of endogenous steroids in human fluids.

Herein, a novel magnetic effervescence tablet-assisted microextraction coupled to in situ metathesis reaction of ionic liquid (IS-META-ILDM) is presented for the determination of four endogenous steroids in human urine, pregnant women's blood, and fetal umbilical cord blood. The magnetic effervescent tablets, which were composed of Fe3O4 nanoparticles, sodium carbonate (alkaline source), and tartaric acid (acidic source), were used to disperse the extractant and for convenient magnetic separation. After the effervescent reaction, in situ reaction between NH4PF6 and [C6MIM]BF4 was adopted to change hydrophilic ionic liquid to hydrophobic liquid, which could be separated from the aqueous phase. The newly developed method has three obvious advantages: (1) combination of effervescent dispersion and magnetic nanoparticles' retrieval is cost-effective and the dispersion and collection of the extractant can be completed almost simultaneously; (2) as compared to temperature-controlled ionic liquid dispersive microextraction and cold-induced solidified microextraction, this method avoids a heating and cooling process which significantly reduces the extraction time and energy cost; and (3) the combination of adsorption by magnetic nanoparticles with extraction by in situ metathesis reaction easily produces high recoveries for target analytes. The optimized composition of effervescent tablet and experimental parameters are as follows: 0.64g mixture of sodium carbonate and tartaric acid, 7mg of Fe3O4 (20nm) as magnetic sorbents, 40μL of [C6MIM]BF4 as the extraction solvent, 0.15g NH4PF6, and 300μL of elution solvent. Under the optimized conditions, the newly developed method provided high extraction recoveries (90.0-118.5%) and low LODs (0.14-0.17μgL-1) in urine and blood samples. In total, this IS-META-ILDM method provided high extraction efficiency, fast and convenient separation, and underutilization of any organic solvent, and thus it has great potential for the determination of trace endogenous steroids in complex human fluids. Graphical abstract The newly developed method has three obvious advantages: combination of effervescent dispersion and magnetic nanoparticles' retrieval is cost-effective and the dispersion and collection of the extractant can be completed almost simultaneously. It avoids a heating and cooling process which significantly reduces the extraction time and energy cost and easily produces high recoveries for target analytes.

Improving the Efficiency of New Automatic Dishwashing Detergent Formulation by Addition of Thermostable Lipase, Protease and Amylase.

The use of T1 lipase in automatic dishwashing detergent (ADD) is well established, but efficiency in hard water is very low. A new enzymatic environmentally-friendly dishwashing was formulated to be efficient in both soft and hard water. Thermostable enzymes such as T1 lipase from Geobacillus strain T1, Rand protease from Bacillus subtilis strain Rand, and Maltogenic amylase from Geobacillus sp. SK70 were produced and evaluated for an automatic dishwashing detergent formulation. The components of the new ADD were optimized for compatibility with these three enzymes. In compatibility tests of the enzymes with different components, several criteria were considered. The enzymes were mostly stable in non-ionic surfactants, especially polyhydric alcohols, Glucopon UP 600, and in a mixture of sodium carbonate and glycine (30:70) buffer at a pH of 9.25. Sodium polyacrylate and sodium citrate were used in the ADD formulation as a dispersing agent and a builder, respectively. Dishwashing performance of the formulated ADDs was evaluated in terms of percent of soil removed using the Leenert‘s Improved Detergency Tester. The results showed that the combination of different hydrolysis enzymes could improve the washing efficiency of formulated ADD compared to the commercial ADD “Finish” at 40 and 50 C.

Leaching behaviour and the solution consumption of uranium–vanadium ore in alkali carbonate–bicarbonate column leaching

Although heap leaching using sulfuric acid was introduced to the uranium industry in the 1950s, sodium carbonate–bicarbonate (alkaline) heap leaching of low-grade Ca-carbonate-rich uranium ores has recently gained popularity. This study presents the results of two column tests on a calcrete-type uranium–vanadium (carnotite) ore using a mixture of sodium carbonate and bicarbonate (Na2CO3/NaHCO3) as the leach solution. This data was kindly supplied by Toro Energy Ltd. The experimental data comprised physical–chemical leach information and two different irrigation rates (10 and 20L/h·m2). The experimental data indicated that the carnotite ore with high calcium carbonate (CaCO3) can be leached effectively using the alkaline leach solution. The increase in the irrigation rate increased the uranium and vanadium extraction and decreased their concentration in the effluent.The column leach data was therefore fitted to a simplified first-order kinetic model using two approaches, a general form and a second based on the reagent consumption per unit mass of the initial valuable species (U and V). As reagent consumption is a key economic factor in the heap leaching process, having a kinetic leaching model incorporating reagent consumption would provide useful techno-economic information. In this regards a new leaching index of (β) is also introduced. Both approaches of the first order kinetic model provide a good agreement with the column testing data.

Investigation of wood fire resistance mechanism in modifying by impregnating agents

Application of the modifiers for wood surface treatment is considered and some results of our research in this field are given in the paper. The main purpose of the research is to investigate the mechanism of thermal decomposition of wood and effect of modification on the thermal degradation. The process of thermal degradation of modified wood by chromatography was studied. The qualitative and quantitative analysis of the obtained products was carried out. Coke residue in the treated samples was increased by 4 times and the amount of flammable gases was reduced, in particular for wood, treated with a mixture of ammonium phosphate and sulphate the amount of nitrogen was increased by more than 80 times, for wood treated with a mixture of sodium carbonate and boric acid, carbon dioxide was increased by 1.5 times, and for wood treated with a mixture of sodium orthoborate and boric acid – more than 10% of flammable gases, the amount of carbon dioxide was slightly increased. The research results can be applied in the development of effective modifiers and in the determination of operational conditions of wooden structures.

Formulation and Evaluation of an Automatic Dishwashing Detergent Containing T1 Lipase

AbstractThe use of enzymes in detergent formulations is becoming popular due to the concerns about the environment. T1 lipase (E.C. 3.1.1.3) was evaluated for its stability and performance in dishwashing along with other common components of an automatic dishwashing detergent. Therefore, the process of formulating the detergent would depend on the stability of T1 lipase, which may also reflect the performance during the washing. T1 lipase was mostly stable in nonionic surfactants, especially those that were made of polyhydric alcohols. T1 lipase was also stable in a mixture of sodium carbonate and glycine. However, sodium carbonate alone destabilized T1 lipase possibly due to the interaction between carbonates and Ca2+. These results indicated that polyhydric alcohols and glycine had stabilizing effects on T1 lipase. The dishwashing performance was evaluated in term of percent soil removed. The dishwashing performance of the formulated detergent was positively affected by the increase in temperature but negatively affected by the presence of hard water, specifically Ca2+ and Mg2+. However, T1 lipase was not negatively affected by the presence of hard water, and this enzyme was enhanced by the presence of polyacrylates. The presence of Ca2+ improved the structural integrity of T1 lipase. It is generally known that most enzymes that depend on Ca2+ for their structural integrity would be greatly destabilized in the presence of metal chelators; thus, stabilizing strategies such as adding glycine would be essential to maintain enzyme activity during the wash.

Effect of Additive on the Performance Characteristics of Centrifugal and Progressive Cavity Slurry Pumps with High Concentration Fly Ash Slurries

Slurry pumps that are used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants can be broadly classified into two main categories namely positive displacement and centrifugal pumps. The two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The present study reports the effect of additive on the performance characteristics of centrifugal and progressive cavity screw pumps with fly ash slurries at high concentrations (above C~w~ AP 50% by weight). Mixture of sodium carbonate and Henko detergent (5:1) at a concentration of 0.2% by weight has been used as an additive. For each type of pump, the effect of additive on the performance characteristics has been experimentally evaluated at rated speed with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency and pump input power as a function of flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the performance of the pump improves with the addition of drag reducing additive. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different as compared to the centrifugal slurry pump. At rated speed, the performance of screw pump deteriorates with the addition of drag reducing soap solution.

Behavior of impurity metals in the fusion of magmatic rocks with a mixture of sodium carbonate and calcium oxide

The method of physicochemical simulation is used to calculate the equilibrium compositions of SiO2-Al2O3-(TiO2)-CaO-MgO-Fe2O3-(MnO)-Na2O-(Cr2O3)-(V2O5) systems in the temperature range of 1273–1473 K at various ratios of (Na2CO3 + CaO): rock. It is shown that the impurity metals are present in fusion products in the form of calcium polytitanate (Ca3Ti2O7), manganese(II, III) oxide (Mn3O4), chromium(III) oxide (Cr2O3), and calcium orthovanadate (Ca3V2O8).

Effect of the material structure and nanoadditive type on the thermal properties of nanocomposite alginate fibres

Abstract Thermal properties of sodium alginate and calcium alginate fibres containing nanoadditives were analysed. Thermal decomposition of fibres based on sodium alginate, both pure and containing nanoadditive, produces sodium carbonate (for fibres without nanoadditive) or, for modified fibres, a mixture of sodium carbonate with the corresponding nanoadditive, which does not undergo any changes within the range of measured temperatures. The chief gaseous products accompanying the decomposition are carbon (IV) oxide and water. The shape of the DTG curves and values of the ∗T50 coefficient indicate an improvement in the thermal properties of the fibres when ceramic nanoadditives (SiO2 and HAp) are introduced, as compared with pure sodium alginate fibres. When ceramic nanoadditives (MMT, SiO2, bioglass) are added to the material of calcium alginate fibres the nature of the thermal processes is not affected. However, similarly as for sodium alginate fibres modified with nanoadditive, here also it was note th...

Effect of Additive on the Performance Characteristics of Centrifugal and Progressive Cavity Slurry Pumps with High Concentration Fly Ash Slurries

Slurry pumps that are used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants can be broadly classified into two main categories namely positive displacement and centrifugal pumps. The two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The present study reports the effect of additive on the performance characteristics of centrifugal and progressive cavity screw pumps with fly ash slurries at high concentrations (above C~w~ AP 50% by weight). Mixture of sodium carbonate and Henko detergent (5:1) at a concentration of 0.2% by weight has been used as an additive. For each type of pump, the effect of additive on the performance characteristics has been experimentally evaluated at rated speed with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency and pump input power as a function of flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the performance of the pump improves with the addition of drag reducing additive. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different as compared to the centrifugal slurry pump. At rated speed, the performance of screw pump deteriorates with the addition of drag reducing soap solution.

Effect of Additive on the Performance Characteristics of Centrifugal and Progressive Cavity Slurry Pumps with High Concentration Fly Ash Slurries

Slurry pumps that are used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants can be broadly classified into two main categories namely positive displacement and centrifugal pumps. The two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The present study reports the effect of additive on the performance characteristics of centrifugal and progressive cavity screw pumps with fly ash slurries at high concentrations (above Cw AP 50% by weight). Mixture of sodium carbonate and Henko detergent (5:1) at a concentration of 0.2% by weight has been used as an additive. For each type of pump, the effect of additive on the performance characteristics has been experimentally evaluated at rated speed with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency and pump input power as a function of flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the performance of the pump improves with the addition of drag reducing additive. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different as compared to the centrifugal slurry pump. At rated speed, the performance of screw pump deteriorates with the addition of drag reducing soap solution.

Mechanisms and orientation dependence of the corrosion of single crystal Cordierite by model diesel particulate ashes

Cordierite Mg 2Al 4Si 5O 18 is a material for diesel particulate filters (DPF) with high potential. Its resistance to two simplified model ashes has been tested on single crystals at temperatures up to 1050 °C, which are realistic for use under ‘worst case’ conditions. Single crystals were examined in order to investigate the orientation dependence of attack due to the strongly anisotropic nature of the Cordierite crystal lattice. A mixture of sodium carbonate and silica was used to study the attack of an alkali-rich ash composition and a mixture of the Ca, Mg and Zn orthophosphates to study an ash composed of typical main constituents of ashes found in DPF used in traffic. The sodium-rich ash formed a melt and attacked the Cordierite by dissolving it. No anisotropy in the corrosion was observed, because the attack is controlled by outward diffusion of Mg. A kinetic break occurs in the system, caused by the formation of a Nepheline product layer, slowing down corrosion. A much stronger corrosion of Cordierite occurs by the phosphate mixture at 1050 °C. Excessive melt formation from the ash causes fast dissolution of the substrate with melt saturation within minutes. Anisotropy of the dissolution process could not be detected. The initial kinetics is dominated by saturation effects, which slow down corrosion. The saturated melt attacks Cordierite by reaction processes leading to the formation of new crystalline phases. This process is much slower than the initial dissolution process but may significantly contribute to the destruction of Cordierite substrates if large contact areas between ash melt and Cordierite exist. Additionally, the formation and local growth of crystalline phases causes the extension of faults, which may eventually become critical.

Physicochemical simulation of fusion processes of basalt and diabase with Na2CO3 and Na2CO3 + CaO

Fusion processes of basalt and diabase with sodium carbonate and its mixture with calcium oxide are investigated by methods of physicochemical simulation. Equilibrium compositions of the Si-Al-Fe-Ca-Mg-Na system are calculated at various ratios Na2CO3: basalt (diabase) and (Na2CO3 + CaO): basalt (diabase) in the temperature range of 1270–1470 K. It is shown that, on fusion with sodium carbonate, depending on conditions, the main components of fusion products are sodium metasilicate (Na2SiO3) and sodium metaaluminate (NaAlO2), magnesium orthosilicate (CaMgSiO4), sodium ferrite(III) (NaFeO2), iron(III) oxide (Fe2O3), and sodium-aluminum orthosilicate (Na2AlSiO4). On fusion with the mixture of sodium carbonate and calcium oxide, respectively, the products are sodium metaaluminate, calcium pyrosilicate (Ca3Si2O7), calcium-magnesium orthosilicate, and calcium ferrite (CaFe2O4).

Synthesis and Characterization of the Ultramarine-Type Analog Na8−x[Si6Al6O24]·(S2,S3,CO3)1−2

The use of nitrite sodalite as a precursor to prepare new blue ultramarine analogs has been investigated. The encapsulation of the chromophores inside of beta cages was achieved by heating the nitrite sodalite precursor with a mixture of sodium carbonate, sulfur, and a reducing agent at about 1000 K under airtight conditions. The obtained new blue ultramarine-type material was characterized by means of X-ray and neutron powder diffraction, transmission electron microscopy, 29Si magic-angle-spinning NMR, IR, Raman, and diffuse reflectance spectroscopies. Thermogravimetric analysis and magnetic measurements were performed in order to determine water and chromophore contents, respectively. On the basis of the spectroscopic results and Rietveld analysis of neutron powder data, the beta cage filling was found to be yellow S2(-) and blue S3(-) chromophores along with carbonate anions. The determined chromophore concentration, about 0.31 mol per formula unit, is enough to have greenish-blue ultramarines, which proves that ultramarine analogs can be obtained from nitrite sodalite.

Effect of Additive on Pressure Drop and Rheological Characteristics of Fly Ash Slurry at High Concentration

The present study reports the effect of additive on pressure drop and rheological characteristics of fly ash slurry at high concentration (above C w ≈ 60% by weight). Pressure drop has been measured using a pilot plant test loop for fly ash slurry at various concentrations with and without additive. Mixture of sodium carbonate and Henko detergent has been used as a additive. Rheological studies are also carried out for fly ash slurry at the same concentrations. By using the rheological data, pressure drop has been predicted in a straight pipeline of 40 mm diameter at higher concentrations. Experimental results obtained from a pilot plant test loop were compared to the analytical results based on the Darby and Melson (1981) algorithm. The comparison showed very good agreement between these sets of data, and it is found that there is reduction in pressure drop when additive like soap solution is added to the fly ash slurry at higher concentrations.

The Mechanochemical Synthesis of NaNbO3Using Different Ball‐Impact Energies

We studied the mechanochemical synthesis of NaNbO3from a starting‐powder mixture of sodium carbonate and Nb2O5using ball‐impact energies of 15 and 370 mJ/hit. Based on the results of a quantitative phase analysis we propose a mechanism for the mechanochemical synthesis of NaNbO3. During milling a condition is established, where the amounts of perovskite, X‐ray diffraction ‐amorphous phase and residual carbonate in the mixture do not change with increasing milling time. Similarly, the NaNbO3crystallite size and the quantity of microstrains reach final values that are independent of the applied ball‐impact energy.