Showing papers on "Carbonic acid published in 2020"

Effect of Mechanical Shaking on the Physicochemical Properties of Aqueous Solutions.

Abstract: Long-lived luminescence in the blue region was found to occur in deionized water saturated with atmospheric gases following mechanical shaking. Luminescence intensity decreased exponentially after the cessation of stress. During vigorous mechanical shaking, we observed gas bubbles in solution, and the liquid-gas interface area increased noticeably. At the same time, the concentration of molecular oxygen decreased, which could not be attributed to the water warming up with exposure to mechanical stress. However, deaerated water rapidly became saturated with gases following mechanical stress. The recommendation that cell culture media should be mixed after they are removed from the fridge in order to allow saturation with oxygen is probably misleading. It was shown that gases existed in water both in the form of individual molecules and nanobubbles. Mechanical stress did not influence the number or size of nanobubbles. While gas nanobubbles were absent in freshly prepared deaerated water, they appeared following exposure to mechanical stress. In addition, in mechanically treated gas-saturated water, there was seemingly an equilibrium shift towards the decomposition of carbonic acid to water and carbon dioxide. At the same time, the pH of water tended to increase immediately after mechanical stress. It was demonstrated that reactive oxygen species (ROS) form in gas-saturated water under mechanical stress (30 Hz, amplitude of 5 mm). The relative generation rate of hydrogen peroxide and of the hydroxyl radical was 1 nM/min and 0.5 nM/min, respectively. It was found that with an increase in the frequency of mechanical action (f), the rate of ROS generation increased in proportion to f 2. The major pathways for hydrogen peroxide generation are probably associated with the formation of singlet oxygen and its further reduction, and the alternative pathway is the formation of hydrogen peroxide as a result of hydroxyl radical recombination.

Current estimates of K 1 * and K 2 * appear inconsistent with measured CO 2 system parameters in cold oceanic regions

Abstract: . Seawater absorption of anthropogenic atmospheric carbon dioxide ( CO2 ) has led to a range of changes in carbonate chemistry, collectively referred to as ocean acidification. Stoichiometric dissociation constants used to convert measured carbonate system variables (pH, pCO2 , dissolved inorganic carbon, total alkalinity) into globally comparable parameters are crucial for accurately quantifying these changes. The temperature and salinity coefficients of these constants have generally been experimentally derived under controlled laboratory conditions. Here, we use field measurements of carbonate system variables taken from the Global Ocean Data Analysis Project version 2 and the Surface Ocean CO2 Atlas data products to evaluate the temperature dependence of the carbonic acid stoichiometric dissociation constants. By applying a novel iterative procedure to a large dataset of 948 surface-water, quality-controlled samples where four carbonate system variables were independently measured, we show that the set of equations published by Lueker et al. (2000), currently preferred by the ocean acidification community, overestimates the stoichiometric dissociation constants at temperatures below about 8 ∘ C. We apply these newly derived temperature coefficients to high-latitude Argo float and cruise data to quantify the effects on surface-water pCO2 and calcite saturation states. These findings highlight the critical implications of uncertainty in stoichiometric dissociation constants for future projections of ocean acidification in polar regions and the need to improve knowledge of what causes the CO2 system inconsistencies in cold waters.

Current estimates of K1* and K2* appear inconsistent with measured CO2 system parameters in cold oceanic regions

Abstract: Seawater absorption of anthropogenic atmospheric carbon dioxide (CO2) has led to a range of changes in carbonate chemistry, collectively referred to as ocean acidification. Stoichiometric dissociation constants used to convert measured carbonate system variables (pH, pCO2, dissolved inorganic carbon, total alkalinity) into globally comparable parameters are crucial for accurately quantifying these changes. The temperature and salinity coefficients of these constants have generally been experimentally derived under controlled laboratory conditions. Here, we use field measurements of carbonate system variables taken from the Global Ocean Data Analysis Project version 2 and the Surface Ocean CO2 Atlas data products to evaluate the temperature dependence of the carbonic acid stoichiometric dissociation constants. By applying a novel iterative procedure to a large dataset of 948 surface-water, quality-controlled samples where four carbonate system variables were independently measured, we show that the set of equations published by Lueker et al. (2000), currently preferred by the ocean acidification community, overestimates the stoichiometric dissociation constants at temperatures below about 8 ∘C. We apply these newly derived temperature coefficients to high-latitude Argo float and cruise data to quantify the effects on surface-water pCO2 and calcite saturation states. These findings highlight the critical implications of uncertainty in stoichiometric dissociation constants for future projections of ocean acidification in polar regions and the need to improve knowledge of what causes the CO2 system inconsistencies in cold waters.

Chlorinated wash water and pH regulators affect chlorine gas emission and disinfection by-products

Abstract: In the washing operations of fruit and vegetables, the maintenance of an appropriate range of pH in the water when using chlorine is crucial to ensure the maximum concentration of hypochlorous acid (HOCl), the form of chlorine with the highest antimicrobial activity. In this study, the effect of two inorganic acids (phosphoric and sulfuric) and two organic acids (carbonic and citric) as pH regulators was evaluated. Chlorinated wash water was generated using sodium hypochlorite as a chlorine source. The results showed that the optimal pH range with >90% of chlorine as HOCl was between 5.0 and 6.0 for all pH regulators. Phosphoric acid and sulfuric acid provided a wider pH range (3.0–6.0) for the maximum HOCl concentration than citric acid and carbonic acid (4.5–6.0 and 5.0–6.0, respectively). When citric acid was used as a pH regulator, a reduction of available chlorine was observed at pH

CO2-Gas-Responsive Liquid Marble.

Abstract: Liquid marbles were prepared using a water droplet and nonprotonated hydrophobic poly(2-N,N-diisopropylaminoethyl methacrylate) (PDiPAEMA) powder. Although the nonprotonated PDiPAEMA was hydrophobic, PDiPAEMA became hydrophilic because of the protonation of the pendant tertiary amino groups under acidic conditions. Therefore, liquid marbles stabilized with PDiPAEMA powder could float on a neutral to basic water surface, but they immediately disintegrated on an acidic water surface. Furthermore, the liquid marbles floating on the water surface disintegrated in response to CO2 gas because the water became acidic as a result of carbonic acid formation.

Spectroscopic evidence for intact carbonic acid stabilized by halide anions in the gas phase

Abstract: This work shows elusive carbonic acid being effectively stabilized in the gas phase by interacting with halide anions X− (X = F, Cl, Br, and I). The formed H2CO3·X− complexes, characterized by negative ion photoelectron spectroscopy and ab initio calculations, all contain intact trans–trans carbonic acid binding onto the respective halide via two identical strong ionic O–H⋯X− hydrogen bonds. For X = Cl, Br, and I, the complex spectra exhibit the corresponding X− signature by simply shifting to the higher binding energy side, while an extremely 2 eV wide broader band is observed for X = F. This spectroscopic evidence indicates that an excess electron is removed from each halide in the former case, while a proton is transferred from carbonic acid to fluoride upon electron detachment for the latter. The above H2CO3·X− structures as well as those of the previously studied H2SO4·X− along the homologous halogen series cannot be explained using the proton affinity (PA) argument. Instead, a qualitative correlation is found between these structural motifs and the constituent acid pKa values, strongly suggesting that pKa is a more suitable factor to predict correct acid–base chemistry between these diprotic oxyacids and halides.

The mechanism of stabilization of silver nanoparticles by chitosan in carbonic acid solutions

Abstract: The aim of the current study was to investigate the growth mechanisms of the silver nanoparticles (Ag NPs) in chitosan macrogels and microgels acting both as reductants and stabilizing agents in self-neutralizing, biocompatible, and environmentally benign carbonic acid solutions The chitosan-hydroquinone microgels loaded with Ag NPs incorporated in carbonic acid solutions were successfully prepared However, it was found that during the reduction of nanoparticles by hydrogen, the microgels tend to deteriorate Yet, it was found that the duration of the process of silver reduction by chitosan in the composite macrogels obtained in a solution of carbonic acid took no more than 1 month The process of the reduction was accompanied by the appearance of relatively small aggregates of Ag NPs uniformly distributed in the volume of the hydrogel Such a “gentle” reduction of Ag NPs allows to avoid the loss of mechanical stability of the gel

Alpha-Carbonic Acid Revisited: Carbonic Acid Monomethyl Ester as a Solid and its Conformational Isomerism in the Gas Phase

Abstract: In this work, earlier studies reporting α-H2 CO3 are revised. The cryo-technique pioneered by Hage, Hallbrucker, and Mayer (HHM) is adapted to supposedly prepare carbonic acid from KHCO3 . In methanolic solution, methylation of the salt is found, which upon acidification transforms to the monomethyl ester of carbonic acid (CAME, HO-CO-OCH3 ). Infrared spectroscopy data both of the solid at 210 K and of the evaporated molecules trapped and isolated in argon matrix at 10 K are presented. The interpretation of the observed bands on the basis of carbonic acid [as suggested originally by HHM in their publications from 1993-1997 and taken over by Winkel et al., J. Am. Chem. Soc. 2007 and Bernard et al., Angew. Chem. Int. Ed. 2011] is inferior compared with the interpretation on the basis of CAME. The assignment relies on isotope substitution experiments, including deuteration of the OH- and CH3 - groups as well as 12 C and 13 C isotope exchange and on variation of the solvents in both preparation steps. The interpretation of the single molecule spectroscopy experiments is aided by a comprehensive calculation of high-level ab initio frequencies for gas-phase molecules and clusters in the harmonic approximation. This analysis provides evidence for the existence of not only single CAME molecules but also CAME dimers and water complexes in the argon matrix. Furthermore, different conformational CAME isomers are identified, where conformational isomerism is triggered in experiments through UV irradiation. In contrast to earlier studies, this analysis allows explanation of almost every single band of the complex spectra in the range between 4000 and 600 cm-1 .

Second Dissociation Constant of Carbonic Acid in H2O and D2O from 150 to 325 °C at p = 21 MPa Using Raman Spectroscopy and a Sapphire-Windowed Flow Cell.

Abstract: Solvent-corrected reduced isotropic spectra of carbonate and bicarbonate in light and heavy water have been measured from 150 to 325 °C at 21 MPa using a confocal Raman microscope and a custom-built titanium flow cell with sapphire windows. The positions of the symmetric vibrational modes of CO32- and HCO3-/DCO3- were compared to density functional theory (DFT) calculations with a polarizable continuum model in light and heavy water. The experimental Raman peak positions shifted linearly toward lower wavenumbers with increasing temperatures. Raman scattering coefficients, measured relative to a perchlorate internal standard, were used to determine equilibrium molalities of the carbonate and bicarbonate species. These yielded quantitative thermodynamic equilibrium quotients for the reaction CO32- + H2O ⇌ HCO3- + OH- and its deuterium counterpart. Ionization constants for HCO3- and DCO3-, K2a,H,m and K2a,D,m, calculated in their standard states using the Meissner-Tester activity coefficient model, were combined with critically evaluated literature data to derive expressions for their dependence on temperature and pressure, expressed as solvent molar volume, over the range 25 to 325 °C from psat to 21 MPa. These are the first experimental values to be reported for this reaction in light water above 250 °C and in heavy water above 25 °C. The value of the deuterium isotope effect on the chemical equilibrium constant, ΔpK2a,m = pK2a,D,m - pK2a,H,m, decreased from ΔpK2a,m = 0.67 ± 0.07 at 25 °C to ΔpK2a,m = 0.17 ± 0.13 at 325 °C and psat.

Deposition of a Chitosan Coating on Celgard Porous Matrices in the Presence of Carbon Dioxide under Pressure

Abstract: It is shown that a chitosan coating can be deposited on the pore surface of Celgard polyolefin matrices from aqueous solutions of chitosan saturated with carbon dioxide under high pressure; i.e., when carbonic acid is formed. To ensure the stability of the coating, the initially hydrophobic matrices should be pretreated in the presence of peroxycarbonic acid, which is formed when the aqueous solution of hydrogen peroxide is saturated with carbon dioxide at a high pressure. The morphology of the deposited coating is studied by high-resolution microscopy. The introduced hydrophilic properties are evaluated from a change in the nature of the wetting of the matrix surface with water. It is found that the hydrophilized matrix modified with chitosan, in spite of a lower characteristic pore size, has ~1.5 times higher permeability for water than the initial matrix.

Effect of Jet Impingement Velocity and Angle on CO2 Erosion-Corrosion with and without Sand for API 5L-X65 Carbon Steel.

Abstract: Most oil and gas production wells have plenty of corrosive species present along with solid particles. In such production environments, CO2 gas can dissolve in free phase water and form carbonic acid (H2CO3). This carbonic acid, along with fluid flow and with/without solid particles (sand or other entrained particles), can result in unpredictable severe localized CO2 corrosion and/or erosion-corrosion (EC). So, in this work, the CO2 EC performance of API 5L X-65 carbon steel, a commonly used material in many oil and gas piping infrastructure, was investigated. A recirculating flow loop was used to perform these studies at three different CO2 concentrations (pH values of 4.5, 5.0, and 5.5), two impingement velocities (8 and 16 m/s), three impingement angles (15°, 45°, and 90°), and with/without 2000 ppm sand particles for a duration of 3 h in 0.2 M NaCl solution at room temperature. Corrosion products were characterized using FE-SEM, EDS, and XRD. The CO2 EC rates were found to decrease with an increase in the pH value due to the increased availability of H+ ions. The highest CO2 erosion-corrosion rates were observed at a 45° impingement angle in the presence of solid particles under all conditions. It was also observed that a change in pH value influenced the morphology and corrosion resistance of the corrosion scales.

Rapid hydration mechanism of carbonic acid and cement

Abstract: Early-age carbonation is an attractive option to reduce the net CO2 emissions of cementitious materials. Applying early-age carbonation to the most common cementitious material, ready-mix concrete, is difficult as the process must be performed in atmosphere. A technique that could supply a large quantity of CO2 to cement in atmosphere is by mixing powdered cement with a super-saturated aqueous solution. However, this would create an acidic solution. This paper addresses the competing effects of dissolved CO2 ions and carbonic acid when mixed with cement paste or mortar. While CO2 is expected to form carbonates, carbonic acid usually decreased the strength of cement. The cement replacement fraction, and the strength and porosity of the original mix alter the relative effect of carbonic acid on compressive strength. The most likely cause of strength and workability losses are identified as a very rapid but limited hydration in the first 10 min after mixing.

Carbonic Acid Resistance of Hydroxyapatite-Containing Cement

Abstract: With the current applications of carbon dioxide (CO2) in oil wells for enhanced-oil-recovery (EOR) and sequestration purposes, the dissolution of CO2 in the formation brine, and the resulting formation of carbonic acid (H2CO3), is a major cause of cement damage. This degradation can lead to noncompliance with the functions of the cement because it changes compressive strength and shear-bond strength (SBS) and the porosity and permeability of cement. It becomes imperative to understand the degradation mechanism of cement and methods to reduce the damage, such as the use of special additives to improve the resistance of cement to an acid attack. Hence, the primary objective of this study is to investigate the effects of hydroxyapatite on cement degradation. To investigate the effects of hydroxyapatite additive on oil-well-cement performance, two Class H cement slurry formulations [the baseline Class H cement containing silica flour (HS) and the hydroxyapatite-containing cement (HHO), a Class H cement containing 5% hydroxyapatite by weight of cement (BWOC)] were compared after exposure to acidic environments. To evaluate the performance of the formulations, samples were prepared and aged in a high-pressure/high-temperature (HP/HT) autoclave containing 2% brine saturated with mixed gas containing methane (CH4) and CO2. Tests were performed at different temperatures (38 to 221°C), pressures (21 to 63 MPa), and CO2 concentrations (10 to 100%). After aging for 14 days at constant pressure and temperature, the samples were recovered and their bond strength and compressive strength and their porosity and permeability (i.e., overall apparent permeability) were measured and compared with those of unaged samples. The results demonstrated that adding hydroxyapatite limits carbonation. Baseline samples that did not contain hydroxyapatite carbonated, and consequently their compressive strength, porosity, permeability, and SBS significantly changed after aging, whereas hydroxyapatite-containing samples displayed a limited change in their properties. However, hydroxyapatite-containing samples exhibit high permeability because of the formation of microcracks after exposure to H2CO3 at high temperature (221°C). The formation of microcracks could be attributed to thermal retrogression or other phenomena that cause the expansion of the cement. This paper sheds light on the application of hydroxyapatite as a cement additive to improve the H2CO3 resistance of oilwell cement. It presents a hydroxyapatite-containing cement formulation that has acceptable slurry properties for field applications and better H2CO3 resistance compared with conventional cement.

Accelerated Weathering of Limestone for CO 2 Mitigation

Abstract: Rock weathering is a natural phenomenon which brings about several changes on the Earth’s landscape but it has one more useful function. It controls the CO2 concentration in the atmosphere by precipitating the magnesium and calcium carbonates. The process is slow and takes place over a long period of time. However, if this process is accelerated, the atmospheric CO2 can be removed in sufficient volumes at a faster rate and converted to bicarbonates thus mitigating the greenhouse effect. A geochemistry-based capture and sequestration process that reacts CO2 with water to produce a carbonic acid solution is one of the methods to understand this phenomenon. This carbonic acid solution is then reacted with carbonate rocks to precipitate bicarbonates. The rate of reaction depends upon the temperature, flow rate and particle size. In the present study, the accelerated weathering of limestone was carried out using different sizes of limestone cuttings (4 mm, 500, 250, 100 and 50 µm) under different flow rates of carbonic acid (0.5, 1.0 and 1.5 L/min) for a duration of 2 h at a constant temperature of 80 °C. SEM and elemental analysis were done before and after the experiment. Results from the experiment showed that the highest flow rate (1.5 L/min) exhibits the greatest weight loss. This weight loss is brought about by the dissolution of calcium to release bicarbonate and carbonate ions. EDX analysis shows a reduction in both calcite and dolomite indicating dissolution of these two minerals. Acid attack on the samples forms dissolution patterns which are visible in SEM images. The principle mode of sequestration in limestone formation is ionic trapping. CO2 trapped in this way in the form of bicarbonate solution can be safely discharged in a water body or reservoir for storage.

Experimental study of nanoparticles as catalyst in enhancing matrix acidizing for carbonate reservoir

Abstract: Hydrochloric (HCl) acid is the most common stimulating fluid used in acidizing job due to its strong acidic property and low cost to create or enlarge existing wormhole within the reservoir. However, the HCl acid has rapid reaction with carbonate reservoir, and it is causing surface dissolution of the rock and lowering the penetration into the formation. Recent studies have shown the addition of nickel nanoparticles as catalyst to handle the problems in HCl acidizing. The nanoparticles are high-performance catalyst due to their high ratio of surface area to volume. The proposed method in this research is to mix the nanoparticles with the carbonate formation prior to the acid injection into the formation. The efficiency of the nanoparticles as catalyst depends on the thermodynamics property, which is surface energy of the materials used. The surface energy reduces as the size of particles become smaller. However, the effect of surface energy become insignificant on nanoparticles due to the small particles sizes, and the surface energy is based on the individual energy of the particles. Therefore, this research investigates the efficiency of silica, aluminum oxide, and zinc oxide besides nickel nanoparticles based on their thermodynamics property in accelerating the conversion of CO2 gas into carbonic acid. The approach consists of investigating the efficiency of nanoparticles in different concentrations of carbonate and mass of nanoparticles. Suitable nanoparticles are proposed based on efficiency and cost in retarding the HCl reactivity and rapid formation of in situ carbonic acid. The concentration of carbonic acid (H2CO3), bicarbonate ion (HCO3−), and carbonate ion (CO32−) is analyzed based on Henry’s law of solubility. The result shows that the silica has the best efficiency as catalyst in 6700 ppm Na2CO3 solution due to its high stability and dispersion in aqueous solution. The silica engages into rapid dissociation of water molecules and bind with OH− group to react with CO2 gas and form HCO3−. The nanoparticles reduce the reactivity of HCl through conversion of bicarbonate ions. However, ZnO gives better efficiency in 17,000 ppm of Na2CO3. The efficiency of silica in this concentration increased at 0.7 g, proving the minimum amount required as catalyst. In contrast, ZnO and Al2O3 have lower efficiency as acid retarder since changes in pH values affect the performance of the nanoparticles. The surface charge demonstrated by ZnO and Al2O3 depends on pH changes which makes these nanoparticles to perform inefficiently. The silica is chosen as the best catalyst due to high efficiency versus cost ratio.

Preparation method of carbonic acid-hypochlorous acid water

Abstract: The invention belongs to the field of hypochlorous acid preparation, and particularly relates to a carbonic acid-hypochlorous acid water preparation method which comprises the following steps: (1) injecting water into a first injection and suction device, and injecting a sodium hypochlorite solution into the first injection and suction device; (2) adjusting the first injection and suction device,and injecting a mixed solution of water and the sodium hypochlorite solution in the first injection and suction device into a second injection and suction device; (3) injecting carbon dioxide into a second injection and suction device; (4) adjusting the second injection and suction device, and injecting a mixed solution of carbon dioxide, water and a sodium hypochlorite solution into a buffer tank; and (5) in the buffer tank, stirring the mixed solution of carbon dioxide, water and the sodium hypochlorite solution to obtain the carbonic acid-hypochlorous acid water. The carbonic acid-hypochlorous acid water is prepared by mixing the water, the sodium hypochlorite solution and the carbon dioxide through twice injection and stirring, the operation is simple and convenient, the preparation efficiency is high, the power consumption in the preparation process is low, no pollution is caused, and the method is energy-saving and environment-friendly.

Principles of Gold Nanoparticles Stabilization with Chitosan in Carbonic Acid Solutions Under High CO2 Pressure

Abstract: The possibility of reduction and stabilization of gold nanoparticles by chitosan in carbonic acid solutions under high CO2 pressure has been considered for the first time. To analyze the nature of the interaction of the system components, UV-visible and IR spectroscopies have been used. The morphology and size of chitosan-stabilized gold nanoparticles have been determined using TEM. It has been revealed that the stabilization of gold nanoparticles occurs with the participation of amino groups. It has been shown that small spherical nanoparticles are stabilized at a sufficiently high concentration of gold in the solution.

Theoretical Investigations on the Separation of Medetomidine Enantiomers

Abstract: The enantiomeric separation of racemic compounds is of special importance. Conglomerate mixture is of considerable interest, since it corresponds to the possibility of spontaneous resolution of the two enantiomers. The aim of this paper is to find the achiral anions causing conglomerate formation of Medetomidine salts. For this purpose, the effect of 9 anion (X) on the heterochiral structure of Medetomidine enantiomers salts have been studied by Material Studio software. The crystal structures of all systems were determined by quantum calculations of CASTEP module. Investigation of the crystal structures and their respective energy show that Medetomidine salts, formed by Oxalic acid, Maleic acid and Fumaric acid crystalize as conglomerate, favoring preferential crystallization. The AIM results confirmed the more stability of conglomerate crystal in these cases while in the presence of other salting agent as Hydrochloric acid, Acetic acid, Carbonic acid, Formic acid, Malic acid and Lactic acid racemic crystal form is calculated as the more stable crystal. Using Forcite module, the total energy of the crystalline systems (calculated as the sum of the energies of the bonded and non-bonded interactions) are in agreement with those predicted by CASTEP module and AIM calculations.

Catalytic Cyclothiomethylation of Diamides and Dihydrazides of (Thio)carbonic Acid Using Bis(dimethylamino)methane, H2S, and Na2S·9H2O

Abstract: An efficient method for the synthesis of N,S-heterocycles with (thio)amide fragments by the catalytic cyclothiomethylation of diamides and dihydrazides of (thio)carbonic acid with H2S, sodium sulfide crystallohydrate, or bis(dimethylamino)methane has been developed.

Method for synthesizing aryl pyrazonitrile and by-producing carbonic acid diester

Abstract: The invention discloses a method for synthesizing aryl pyrazonitrile and by-producing carbonic acid diester. The method comprises the steps: taking 2,6-dichloro-4-trifluoromethylaniline, 2,3-dicyanopropionate and nitrite as main raw materials, carrying out diazotization and coupling reaction in a solvent containing fatty alcohol, adding a reaction terminating agent after coupling, and then carrying out alcoholysis and cyclization under an alkaline condition to generate aryl pyrazonitrile and carbonic acid diester. Different raw materials and process conditions are selected, the quality and theyield of the aryl pyrazonitrile are not influenced, and the generated by-product is purposefully controlled, so that after the cyclization liquid for synthesizing aryl pyrazonitrile is distilled andseparated, the distillate is subjected to multi-stage rectification, and solvents (methanol, ethanol or propanol and the like) can be recycled; meanwhile, carbonic acid diester of which the quality meets the industrial standard is obtained, and reduction and resource utilization of aryl pyrazonitrile synthesis waste liquid are realized.

Soluble agent containing 6-furfurylaminopurine and gibberellic acid GA4+7 and preparation method thereof

Abstract: The invention relates to a soluble agent containing 6-furfurylaminopurine and gibberellic acid GA4+7 and a preparation method thereof. The soluble agent comprises 6-furfurylaminopurine, gibberellic acid GA4+7, a surfactant and a solvent, and a weight percentage of each component is: 1%-7% of 6-furfurylaminopurine, 1%-2% of gibberellic acid GA4+7, 1%-2% of the surfactant, and the balance the solvent, wherein the surfactant is at least one selected from sodium dodecylbenzene sulfonate, stearic acid, lecithin, fatty acid glyceride, and polysorbate; and the solvent is at least one selected from formic acid, benzoic acid, acetic acid, propionic acid, butyric acid, carbonic acid, stearic acid, dimethylformamide, and dimethyl sulfoxide capable of dissolving 6-furfurylaminopurine, and at least oneselected from methanol and ethanol capable of dissolving gibberellic acid GA4+7. The reasonable compatibility of 6-furfurylaminopurine and gibberellic acid GA4+7 is realized. The problems of environmental pollution and low utilization rate caused by preparing a wettable powder of 6-furfurylaminopurine and gibberellic acid GA4+7 are avoided.

Method for producing lithium carbonate

Abstract: The purpose of the present invention is to provide a method for producing lithium carbonate capable of effectively raising the gas reaction efficiency when dissolving crude lithium carbonate in a liquid under carbon dioxide gas supply. The present invention is a method for producing lithium carbonate from lithium ion battery waste containing a battery positive electrode component containing Li and at least one metal selected from the group consisting of Co, Ni, and Mn, wherein the method includes a dissolution step that subjects the lithium ion battery waste to wet treatment, thereby separating at least one of the above metals of the battery positive electrode component from the lithium ion battery waste to obtain crude lithium carbonate, and then dissolves the crude lithium carbonate in a liquid under supply of carbon dioxide gas and a decarbonation step that heats the lithium solution obtained in the dissolution step and desorbs the carbonic acid, and, when dissolving the crude lithium carbonate in the liquid in the dissolution step, the liquid is stirred using a stirrer in a reactor, and the ratio (d/D) of diameter (d) of the stirring blades of the stirrer to the inner diameter (D) of the reactor is 0.2-0.5.