Showing papers on "Carbonic acid published in 2004"
TL;DR: In this article, the decomposition behavior of five selected amino acids in high-temperature and high-pressure water was studied using a continuous-flow tubular reactor, and the effect of temperature on reaction products, pathway, and rate was determined as a function of reaction time.
Abstract: Decomposition behavior of five selected amino acids in high-temperature and high-pressure water was studied using a continuous-flow tubular reactor. The reaction was carried out in the temperature range of 200−340 °C at a pressure of 20 MPa. Alanine and its derivatives leucine, phenylalanine, serine, and aspartic acid were used as model amino acids. The effect of temperature on reaction products, pathway, and rate was determined as a function of reaction time. Alanine decomposed into lactic acid and pyruvic acid, then finally mineralized to carbon dioxide with an activation energy of 154 [kJ/mol] at 20 MPa. The degradation rate decreased in the following order: aspartic acid, serine, phenylalanine, leucine, and alanine. The general reaction network of amino acids under hydrothermal conditions takes two main paths: deamination to produce ammonia and organic acids, and decarboxylation to produce carbonic acid and amines. Deamination was the predominant reaction in the decomposition of aspartic acid, an ac...
290 citations
TL;DR: It was found that over the range of reaction conditions tested, the presence of carbonic acid had an effect of increasing the concentrations of xylose and furan compounds in the hydrolysate that was significant at above the 99% confidence level.
120 citations
TL;DR: It is postulated that under ambient conditions, carbonic acid may be an important albeit short-lived intermediate in the surface chemistry of calcium carbonate.
Abstract: Calcium carbonate is an important and ubiquitous component of biological and geochemical systems. In this study, the surface chemistry of calcium carbonate with several trace atmospheric gases including HNO3, SO2, HCOOH, and CH3COOH is investigated with infrared spectroscopy. Adsorbed carbonic acid, H2CO3, is found to be an intermediate in these reactions. In the absence of adsorbed water, carbonic acid is stable on the surface at room temperature. However, upon water adsorption, carbonic acid dissociates as indicated by the evolution of gaseous CO2 and the disappearance of infrared absorption bands associated with adsorbed carbonic acid. Thus, it is postulated that under ambient conditions, carbonic acid may be an important albeit short-lived intermediate in the surface chemistry of calcium carbonate.
116 citations
TL;DR: A recently developed accurate semiclassical method is applied, which allows the prediction of the ground-state tunneling splitting of carboxylic acid dimers at a very low cost and the tunneling splittings for parahalogen substituted benzoic acid dimer is predicted.
Abstract: Carboxylic acid dimers in gas phase reveal ground-state tunneling splittings due to a double proton transfer between the two subunits. In this study we apply a recently developed accurate semiclassical method to determine the ground-state tunneling splittings of eight different carboxylic acid derivative dimers (formic acid, benzoic acid, carbamic acid, fluoro formic acid, carbonic acid, glyoxylic acid, acrylic acid, and N,N-dimethyl carbamic acid) and their fully deuterated analogs. The calculated splittings range from 5.3e-4 to 0.13 cm−1 (for the deuterated species from 2.8e-7 to 3.3e-4 cm−1), thus indicating a strong substituent dependence of the splitting, which varies by more than two orders of magnitude. One reason for differences in the splittings could be addressed to different barriers heights, which vary from 6.3 to 8.8 kcal/mol, due to different mesomeric stabilization of the various transition states. The calculated splittings were compared to available experimental data and good agreement was...
75 citations
TL;DR: In this paper, the mode and sites of incorporation of some common inorganic anions (SO42−, NO3− and Cl−) in the calcite crystal lattice were investigated.
Abstract: A number of analytical methods and techniques (X-ray diffraction, FT-IR and electron paramagnetic resonance spectroscopy, ionic chromatography, scanning electron microscopy, etc.) have been used to study the mode and sites of incorporation of some common inorganic anions (SO42−, NO3− and Cl−) in the calcite crystal lattice. Calcite, the thermodynamically stable calcium carbonate polymorph under standard conditions, was prepared by spontaneous precipitation from calcium hydroxide and carbonic acid solutions. The particular co-anion was added into the carbonic acid solution in the form of a calcium salt before mixing the reactants. The system prepared in such a way is particularly suitable for investigating the mode of foreign anion incorporation into the crystal lattice of calcite. Apart from the constituent ions and the products of water protolysis, this system contains only the co-anion examined. In order to study the local environment in the calcite crystal lattice by EPR spectroscopy, Mn2+ was used as a paramagnetic substitute for Ca2+. The experiments were performed at 25 °C and the samples for analyses were taken after a predetermined ageing time of 20 min. It was found that the co-anions, when added in the concentrations examined, did not affect the morphology of the calcite crystals but were incorporated into the calcite structure. The largest distortion of the calcite structure was obtained when sulfate ions were added. The measured parameters of the calcite unit cell are given, the results obtained are discussed and a model that explains the possible mode and sites of sulfate incorporation is presented. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
56 citations
TL;DR: In this article, the corrosion of bare steel under an aqueous boundary layer with dissolved carbon dioxide (CO2) was modeled to investigate the effect of CO2 on steel corrosion.
Abstract: The corrosion of bare steel under an aqueous boundary layer with dissolved carbon dioxide (CO2) was modeled to investigate the effect of CO2. The model incorporated the coupled effect of CO2 diffusion, hydration, local ionic equilibria, ferrous carbonate (FeCO3) precipitation, and steel corrosion. The model was verified against published experimental data under both FeCO3-saturated and unsaturated boundary layers. Good agreement was shown under a variety of conditions. For saturated boundary layers, the results show that the corrosion rate in carbonic acid (H2CO3) is greater than in hydrochloric acid (HCl)for a given pH and that H2CO3 reduction is the cause for the increase of corrosion rate in H2CO3. Increasing temperature was found to increase corrosion rate substantially. This work provides further understanding of the CO2 corrosion mechanism and is a reliable, convenient, and practical tool for predicting the rate of CO2 corrosion.
51 citations
TL;DR: In this article, it has been found that crystalline BaCO3 replaces crystalline Al2O4 in prototypical NOx traps upon exposure to liquid water, where Ba2+ is leached from the aluminate, precipitating as a carbonate under the influence of weak carbonic acid naturally present due to the equilibrium between CO2 in the air and the water.
Abstract: It has been found that crystalline BaCO3 replaces crystalline BaAl2O4 in prototypical NOx traps upon exposure to liquid water. This phenomenon can be understood in terms of acid–base chemistry, where Ba2+ is leached from the aluminate, precipitating as a carbonate, under the influence of weak carbonic acid naturally present due to the equilibrium between CO2 in the air and the water. Consequences of such a redistribution of Ba2+ in a NOx trap could include a decrease in surface area of the trapping material and a loss of contact between the trapping material and the catalytic components, such as Pt. Indeed, preliminary testing has shown that exposure of fully formulated NOx traps to liquid water results in the loss of approximately half of the initial trapping capacity.
33 citations
Patent•
01 Nov 2004TL;DR: In this article, a method of making polycarbonate comprises melting an aromatic dihydroxy compound and a carbonic acid diester in the presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalysts comprises a quaternary phosphonium compound.
Abstract: A method of making polycarbonate comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate the carbonic acid diester, wherein the separated carbonic acid diester has a phosphorous concentration of less than or equal to about 30 parts per million.
28 citations
Patent•
29 Mar 2004
TL;DR: In this article, a nonaqueous electrolyte solution battery with cyclic carbonic acid ester and lithium salt is proposed to provide high-temperature preservation and high-cycle characteristics.
Abstract: PROBLEM TO BE SOLVED: To provide nonaqueous electrolyte solution for a secondary battery with excellent cycle characteristics, high-temperature preservation characteristics and gas generation restraint as well as a nonaqueous electrolyte solution battery with improved cycle characteristics, high-temperature preservation characteristics or the like. SOLUTION: The nonaqueous electrolyte solution battery is structured by using nonaqueous electrolyte solution with cyclic carbonic acid ester, chained carbonic acid ester, carboxylic acid ester, cyclic carbonic acid ester having unsaturated bond, and lithium salt, prepared with a certain range of volume of addition of ionic metal complex expressed in formula (I). Here in formula (I), M denotes transition metal, metal of III, IV, and V groups of the periodic table, m denotes 1 to 4, n denotes 0 to 8, q is either 0 or 1, R 1 denotes C 1 to C 10 alkylene, C 4 to C 20 arylene or the like, R 2 denotes halogen, C 1 to C 10 alkyl group, and X 1 , X 2 denote O, S or the like. COPYRIGHT: (C)2006,JPO&NCIPI
27 citations
TL;DR: This research quantified the enzymatic digestibility of the solid component and the microbial inhibition of the liquid component of pretreated aspen wood and cornstover hydrolysates and showed no difference between pretreatments containing carbonic acid and those not containing nocarbonic acid.
Abstract: This research quantified the enzymatic digestibility of the solid component and the microbial inhibition of the liquid component of pretreated aspen wood and corn stover hydrolysates. Products of liquid hot water and carbonic acid pretreatment were compared. Pretreatment temperatures tested ranged from 180 to 220°C, and reaction times were varied between 4 and 64 min. Both microbial inhibition rates and enzymatic hydrolysis rates showed no difference between pretreatments containing carbonic acid and those not containing no carbonic acid. Microbial inhibition increased as the reaction severity increased, but only above a midpoint severity parameter of 200°C for 16 min. Both the rates and yields of enzymatic hydrolysis displayed an increase from the lowest tested reaction severity to the highest tested reaction severity.
23 citations
Patent•
26 Jul 2004TL;DR: An apparatus and method associated therewith to extract and sequester carbon dioxide (CO2) from a stream or volume of gas wherein said apparatus hydrates CO2 and reacts the resulting carbonic acid with carbonate.
Abstract: An apparatus and method associated therewith to extract and sequester carbon dioxide (CO2) from a stream or volume of gas wherein said apparatus hydrates CO2 and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO2 from a gaseous environment.
TL;DR: In this paper, a benzene solution of (tmeda)PdMe2 or (dppe)PdrMe2 with carbon dioxide gives the corresponding methyl bicarbonate complex, (L-L) PdMe(O2COH), characterized by NMR spectroscopy and elemental analysis.
TL;DR: In this paper, an aerated aqueous boundary layer with imposed cathodic protection (CP) was modeled and it was shown that an imposed CP current decreases the corrosion rate because it changes the steel potential to a more negative value while consuming the oxygen diffusing to the pipe surface as well as the hydrogen ions that dissociate from carbonic acid (H2CO3).
Abstract: Carbon dioxide (CO2) corrosion of bare steel under an aerated aqueous boundary layer with imposed cathodic protection (CP) was modeled. The results show that an imposed CP current decreases the corrosion rate because it changes the steel potential to a more negative value while consuming the oxygen diffusing to the pipe surface as well as the hydrogen ions that dissociate from carbonic acid (H2CO3). This decrease of corrosion rate is greatest near the free corrosion potential and becomes less as the potential is shifted to a more negative value. This change of corrosion rate with the steel potential follows the Tafel relationship between them. At very negative potentials, the reduction of hydrogen ions and H2CO3 to hydrogen is increased and may lead to hydrogen-induced cracking.
Patent•
28 Apr 2004TL;DR: A polycarbonate resin composition obtained by blending polycarbonates from bisphenol A and carbonic acid diester or phosgene in a ratio of (100×(A)/((A)+(B)) = 1 to 99% by weight and a polarizing sheet used the same as mentioned in this paper.
Abstract: A polycarbonate resin composition obtained by blending a polycarbonate resin (A) obtained by forming a carbonate bond from 95 to 5 mol % of a dihydroxy compound having a fluorene structure represented by the general formula (1) and 5 to 95 mol % of a dihydroxy compound having a dimethanol structure represented by the general formula (2) and a carbonic diester and a polycarbonate resin (B) obtained by forming a carbonate bond from bisphenol A and a carbonic acid diester or phosgene in a ratio of (100×(A)/((A)+(B))=1 to 99% by weight and a polarizing sheet used the same.
Patent•
20 Dec 2004
TL;DR: In this paper, an additive for the carbonate beverage consisting of spilanthol, a plant extract or plant essential oil containing the spilsanthol as an active ingredient to improve the carbonic acid feeling caused by the combination of the raw materials such as the fruit juice, a sweetener, a coloring matter, an aromatizing agent, etc.
Abstract: PROBLEM TO BE SOLVED: To provide a carbonate beverage excellent in function and preference as a thirst-satisfying beverage by reinforcing or maintaining a carbonate beverage specific carbonic acid feeling (a refreshing and strong stimulation and feeling on drinking caused by the carbon dioxide gas and also a cool feeling (a fresh feeling) caused by the carbon dioxide and a flavor) which is decreased rapidly after opening a plug by the combination of used raw materials such as a fruit juice, a sweetener, a coloring matter, an aromatizing agent, etc., and by the degassing of carbon dioxide gas. SOLUTION: By adding an additive for the carbonate beverage consisting of spilanthol, a plant extract or plant essential oil containing the spilanthol as an active ingredient to the carbonate beverage, the decrease of the carbonic acid feeling caused by the combination of the raw materials such as the fruit juice, sweetener, etc., is improved. Further, the decrease of the carbonic acid feeling caused by the degassing of the carbon dioxide after opening the plug is inhibited and the function and preference as the thirst-satisfying beverage required originally for the carbonate beverage is maintained after opening the plug. COPYRIGHT: (C)2006,JPO&NCIPI
Patent•
24 Mar 2004
TL;DR: In this paper, a non-aqueous electrolyte secondary battery provided with a positive electrode, a negative electrode, and a nonaqueous solution is defined, where the positive electrode active material is a mixture of lithium-manganese composite oxide and at least one of lithiumnickel composite oxide represented by a general formula LiNi a M1 1-a O 2, and the negative electrode is a saturated cyclic carbonic acid ester having double bond of carbon.
Abstract: In a non-aqueous electrolyte secondary battery provided with a positive electrode, a negative electrode, and a non-aqueous electrolyte solution, a positive electrode active material is a mixture of lithium-manganese composite oxide and at least one of lithium-nickel composite oxide represented by a general formula LiNi a M1 1-a O 2 and lithium-cobalt composite oxide represented by the general formula LiCo b M2 1-b O 2 , and said non-aqueous electrolyte solution contains at least a saturated cyclic carbonic acid ester and an unsaturated cyclic carbonic acid ester having double bond of carbon where content by amount of said unsaturated cyclic carbonic acid ester having double bond of carbon is in a range of 10 × 10 -8 to 24 × 10 -4 g per positive electrode capacity 1 mAh
TL;DR: A 25 membered crownophane with two hydroxy and two amide groups around the cavity has been reported for the first time to be able to include carbonic acid formed from both carbon dioxide and water molecules to give a stable 1 ∶ 1 complex at room temperature.
TL;DR: In this paper, the authors evaluated the impact of landfill gas on ground water using ground water data from a single landfill gas-affected well and found that landfill gas can potentially act as an acid or reducing agent due to its carbon dioxide and methane content, respectively.
Abstract: Concentrations of dissolved inorganic constituents commonly monitored in ground waters at landfills were evaluated during and after a period of landfill gas effects on the ground water. Landfill gas can potentially act as an acid or as a reducing agent (Lewis base) due to its carbon dioxide and methane content, respectively. Ground water data from a single landfill gas-affected well were used to evaluate the correlation of the total volatile organic compound (VOC) concentration (as a general measure of landfill gas effects) with bicarbonate alkalinity, ammonia, calcium, iron, magnesium, manganese, sodium, chloride, and sulfate concentrations. Bicarbonate alkalinity, calcium, and magnesium concentrations were correlated with total VOC concentrations. The correlation with calcium and magnesium concentrations is attributed to increased dissolution of carbonate minerals by carbonic acid from the landfill gas carbon dioxide. Total manganese concentrations also increased with increasing VOC content. This is attributed to reduction of manganese (IV) in aquifer minerals by methane in the landfill gas. No detectable iron was observed during the landfill gas effects or after successful corrective action, suggesting that the redox potential of the ground water was not sufficiently low to reduce iron (III) minerals. There was no correlation observed between total VOC concentrations and chloride, sodium, or sulfate concentrations, and there were insufficient ammonia detections to evaluate. The observed effects of landfill gas are expected to depend on the particular mineralogy and ground water quality of a site. These results and basic chemical principles, however, suggest that landfill gas effects on ground water could cause an increase in bicarbonate alkalinity, calcium, and magnesium concentrations, without increases in sodium or chloride concentrations at many sites. Because municipal solid waste landfill leachate is typically characterized by concentrations of chloride and sodium that are significantly elevated relative to background ground water concentrations, landfill gas effects on ground water could potentially be differentiated from leachate effects by a lack of increases in sodium or chloride concentrations accompanying VOC detections.
01 Jan 2004
TL;DR: In this paper, the authors demonstrate that soil CO2 is a much more potent agent of soil acidification than is generally appreciated, capable of displacing almost all exchangeable base cations in soils, and even elevating Al(III) concentrations in H2CO3-acidified soil waters.
Abstract: Soil acidification is a very important process in the functioning of earth’s ecosystems. A major source of soil acidity is CO2, derived from the respiration of plant roots and microbes, which forms carbonic acid in soil waters. Because elevated atmospheric CO2 often stimulates respiration of soil biota in experiments that test ecosystem effects of elevated atmospheric CO2, we hypothesize that rising atmospheric CO2 (which has increased from � 200ppm since the interglacial and may exceed 550ppm by the end of the 21st century) is significantly increasing acid inputs to soils. Here, using columnleaching experiments with contrasting soils, we demonstrate that soil CO2 is a much more potent agent of soil acidification than is generally appreciated, capable of displacing almost all exchangeable base cations in soils, and even elevating Al(III) concentrations in H2CO3-acidified soil waters. The potent soil acidifying potential of soil H2CO3 is attributed to the low pKa,1 of molecular H2CO3 (3.76 at 251C), which contrasts greatly with that of H2CO � (a convention that combines CO2 (aq) and molecular H2CO3, the pKa,1 of which is 6.36 at 251C). This distinction is significant for soil systems because of soil’s greatly elevated CO2, their variety of sinks for H 1 , and the wide range of contact times between soil solids, water, and gas. Modelling suggests that a doubling of atmospheric CO2 may increase acid inputs from carbonic acid leaching by up to 50%. Combined with the results of CO2 studies in whole ecosystems, this implies that increases in atmospheric CO2 since the interglacial have gradually acidified soils, especially poorly buffered soils, throughout the world.
Patent•
12 Jan 2004
TL;DR: Zinc carbonates such as carbonic acid zinc salt, zinc carbonate hydroxide monohydrate, zinc bicarbonate, zinc tetraamine carbonate and zinc ammonium carbonate can initiate hardening of polyurethane coatings and decrease the coating tack-free time as discussed by the authors.
Abstract: Zinc carbonates such as carbonic acid zinc salt, zinc carbonate hydroxide monohydrate, zinc bicarbonate, zinc tetraamine carbonate, zinc ammonium carbonate, carbamic acid zinc salt and zinc carbamate can initiate hardening of polyurethane coatings and decrease the coating tack-free time. The decreased tack-free times facilitate earlier application of additional polyurethane layers and earlier return of a coated article to service, and can provide improved floor finishes.
Patent•
18 Nov 2004
TL;DR: In this article, the authors provide an apparatus and method for artificially generating heated water containing carbonic acid beneficial to the human body by injecting heated water into a tank filled with CO 2.
Abstract: PROBLEM TO BE SOLVED: To provide an apparatus and method for artificially generating heated water containing carbonic acid beneficial to the human body by injecting heated water into a tank filled with carbonic acid gas. SOLUTION: The lower part of a tank 50 is provided with a connection pipe 44 leading to a water level detection pipe 32 disposed outside the tank, a connection pipe 49 for feeding heated water, and a connection pipe 52 for discharging the heated water. The upper part of the tank forms a carbonic acid gas space by connecting a carbonic acid gas feed pipe 31 to a tank space 33. The tank is also has a discharge control mechanism so as to reserve a certain amount of heated water at the lower part of the tank. An injection nozzle 51 for injecting heated water into the carbonic acid space at the upper part of the tank via a three-way valve 46 from a feed pipe 45 is provided with two or more injection ports each of which injects a different-angled heated water stream so that the flow of the heated water can collide against each other in its injection direction to cause collisions and agitation flow streams in the tank space 33 containing carbonic acid gas. This structure is also provided with a device for producing a high concentration of heated water containing carbonic acid by releasing the air filling the tank 50 at the beginning of the operation in order to improve the solvent efficiency of carbonic acid gas. COPYRIGHT: (C)2006,JPO&NCIPI
TL;DR: The results indicate that combined capital and operating costs of the carbonic acid system are slightly higher than on H2SO4-based system and highly sensitive to reactor pressure and solids concentration.
Abstract: ASPEN-Plus® process modeling software is used to model carbonic acid pretreatment of biomass. ASPEN-Plus was used because of the thorough treatment of thermodynamic interactions and its status as a widely accepted process simulator. Because most of the physical property data for many of the key components used in the simulation of pretreatment processes are not available in the standard ASPEN-Plus property databases, values from an in-house database (INHSPCD) developed by the National Renewable Energy Laboratory were used. The standard non-random-twoliquid (NRTL) or renon route was used as the main property method because of the need to distill ethanol and to handle dissolved gases. The pretreatment reactor was modeled as a “black box” stoichiometric reactor owing to the unavailability of reaction kinetics. The ASPEN-Plus model was used to calculate the process equipment costs, power requirements, and heating and cooling loads. Equipment costs were derived from published modeling studies. Wall thickness calculations were used to predict construction costs for the high-pressure pretreatment reactor. Published laboratory data were used to determine a suitable severity range for the operation of the carbonic acid reactor. The results indicate that combined capital and operating costs of the carbonic acid system are slightly higher than an H2SO4-based system and highly sensitive to reactor pressure and solids concentration.
TL;DR: In this article, the apparent molar volumes of aqueous potassium carbonate and potassium bicarbonate solutions in the ranges (0.014⩽ m /(mol··kg −1 )⊆ 0.51) and (278.15⩾ T /K⩆393.15) at the pressure p = 0.35 MPa were determined.
Patent•
06 Apr 2004
TL;DR: In this article, a vessel body 30 having a hollow part 29 is provided at the end of a circulating track 14 of a bathtub hot water circulating device 10 circulating the hot water in the bathtub 12 by a pump 15, and the bath tub hot water and the carbon dioxide are circulated in the hollow body 29 and jetted out inside the bath-tub 12 as fine air bubbles.
Abstract: PROBLEM TO BE SOLVED: To provide a carbonic acid bath apparatus capable of creating a carbonate spring with a large free carbon dioxide concentration in a simple constitution at low cost by efficiently dissolving carbon dioxide in bathtub water. SOLUTION: A vessel body 30 having a hollow part 29 is provided at the end of a circulating track 14 of a bathtub hot water circulating device 10 circulating the hot water in the bathtub 12 by a pump 15, and the bathtub hot water and the carbon dioxide are circulated in the hollow part 29 and jetted out inside the bathtub 12 as fine air bubbles. This constitution can efficiently dissolve the carbon dioxide in the bathtub hot water to create the carbonate spring with the large free carbon dioxide concentration in the simple constitution at the low cost. COPYRIGHT: (C)2006,JPO&NCIPI
Patent•
24 Jun 2004
TL;DR: In this article, the authors proposed a treatment method for phosphoric acid-containing wastewater which conserves the use amount of a calcium compound when removing the acid by adding the calcium compound to the wastewater containing carbonic acid, reducing the production amount of calcium carbonate/calcium sulfate sludge to reduce a sludge disposal cost and enhancing the content of phosphorus in sludge at the time of recycling as resources.
Abstract: PROBLEM TO BE SOLVED: To provide a treatment method for phosphoric acid-containing wastewater which conserves the use amount of a calcium compound when phosphoric acid is removed by adding the calcium compound to the phosphoric acid-containing wastewater containing carbonic acid, reduces the production amount of calcium carbonate/calcium sulfate sludge to reduce a sludge disposal cost and enhances the content of phosphorus in sludge at the time of recycling as resources. SOLUTION: In the treatment method for the phosphoric acid-containing wastwater which adds alkali to the phosphoric acid-containing wastewater containing carbonic acid in the presence of calcium ions to precipitate phosphoric acid as insolubilized matter and subjects the insolubilized matter to solid-liquid separation treatment to separate the same into sludge containing phosphoric acid insolubilized matter and treated water, an acid is added to the phosphoric acid-containing wastewater containing carbonic acid to adjust the pH of the wastewater to 5 or less and the pH-adjusted wastewater is subjected to aeration treatment not only to perform decarbonization but also to add a mixture, which comprises at least a part of the sludge containing the phosphoric acid insolubilized matter subjected to solid-liquid separation and alkali, to the decarbonated phosphoric acid-containing wastewater. COPYRIGHT: (C)2004,JPO
Patent•
25 Aug 2004
TL;DR: In this article, the electrochemical behavior of a rotating electrode in H2CO3/HCO3/CO32 aqueous solutions was investigated in the pH region from 7 to 9.
Abstract: The electrochemical behaviour of a cobalt rotating electrode in H2CO3/HCO3/CO32 aqueous solutions was investigated in the pH region from 7 to 9. The effects of H2CO3/HCO3/CO32 concentration, pH, and the presence of phosphates as inhibitors was explored using a rotating disc electrode at 1000 rpm. Some potentiodynamic experiments indicate that for pH 8.5 and higher, carbonate and bicarbonate species play a key role on the rate of electrooxidation of cobalt. For pH lower than 8.5, the electrochemical behaviour of cobalt changes drastically and very aggressive corrosion is observed. The involvement of carbonic acid must be considered in the corrosion process of cobalt in this pH region. The study of passive film potential decay under open circuit potential and galvanostatic reduction was performed on preanodized cobalt electrodes in solutions of various compositions. These experiments indicated the phenomena occurring at the electrodesolution interface during the corrosion process. A mechanism involving...
Patent•
09 Sep 2004
TL;DR: In this paper, a method for direct synthesis of a carbonic acid ester in high yield by using carbon monoxide as the carbon source of the carbonated ester was proposed, using a specified palladium complex and a redox catalyst deposited on an inorganic oxide.
Abstract: PROBLEM TO BE SOLVED: To provide a catalyst for direct synthesis of a carbonic acid ester in high yield by using carbon monoxide as the carbon source of the carbonic acid ester, and to provide a method for manufacturing a carbonic acid ester. SOLUTION: An aromatic hydroxyl compound or an aliphatic hydroxyl compound is subjected to oxidative carbonylation reaction with carbon monoxide and oxygen in the presence of the catalyst for manufacturing a carbonic acid ester, the catalyst comprising a specified palladium complex and a redox catalyst deposited on an inorganic oxide (excluding a molecular sieve). COPYRIGHT: (C)2004,JPO&NCIPI
Patent•
01 Mar 2004
TL;DR: In this paper, a process for synthesizing benzaldehyde by selective oxidation of toluene, wherein the catalyst mainly comprises manganese, copper, cobalt, ferrum, nickel, zirconium, zinc, Argentine or/and halides of sodium, calcium, potassium, nitrates, sulfates, acetates, benzoates.
Abstract: Disclosed is a process for synthesizing benzaldehyde by selective oxidation of toluene, wherein the catalyst mainly comprises manganese, copper, cobalt, ferrum, nickel, zirconium, zinc, Argentine or/and halides of sodium, calcium, potassium, nitrates, sulfates, acetates, benzoates. The preparing process comprises letting in oxygen at the presence of the catalyst. When the conversion rate of toluene is 10%, the selectivity of benzaldehyde is 62%, the selectivity of benzoic alcohol is 14%, the selectivity of benzene carbonic acid is 22%, when the conversion rate of toluene is 39%, the selectivity of benzaldehyde is 20%, the selectivity of benzoic alcohol is 5%, the selectivity of benzene carbonic acid is 73%.
Patent•
29 Jul 2004
TL;DR: In this article, a positive electrode 21 and a negative electrode 22 are stacked and wound with a separator 23 in between, and the separator is impregnated with the electrolyte, which contains an aromatic compound such as cyclohexylbenzene having a 5-9C substituent.
Abstract: PROBLEM TO BE SOLVED: To provide an electrolyte allowing the enhancement of capacity and safety at the same time, and a battery using the same. SOLUTION: A positive electrode 21 and a negative electrode 22 are stacked and wound with a separator 23 in between. The positive electrode 21 contains a lithium-nickel compound oxide and a lithium-manganese compound oxide. The separator 23 is impregnated with the electrolyte. The electrolyte contains an aromatic compound such as cyclohexylbenzene having a 5-9C substituent, and a cyclic carbonic acid ester such as vinylene carbonate or vinylethylene carbonate as an unsaturated compound. The aromatic compound serves to prevent heat generation due to an internal short circuit. The cyclic ester serves to achieve a high capacity and excellent cycle characteristics. COPYRIGHT: (C)2004,JPO&NCIPI