Developments of Electrolyte Systems for Lithium–Sulfur Batteries: A Review

Energy Technology Data Exchange (ETDEWEB)

Li, Gaoran; Li, Zhoupeng [College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang (China); Zhang, Bin [Anhui Academy for Environmental Science Research, Hefei, Anhui (China); Lin, Zhan, E-mail: zhanlin@zju.edu.cn [College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang (China)

2015-02-11

With a theoretical specific energy five times higher than that of lithium–ion batteries (2,600 vs. ~500 Wh kg{sup −1}), lithium–sulfur (Li–S) batteries have been considered as one of the most promising energy storage systems for the electrification of vehicles. However, both the polysulfide shuttle effects of the sulfur cathode and dendrite formation of the lithium anode are still key limitations to practical use of traditional Li–S batteries. In this review, we focus on the recent developments in electrolyte systems. First, we start with a brief discussion on fundamentals of Li–S batteries and key challenges associated with traditional liquid cells. We then introduce the most recent progresses in liquid systems, including ether-based, carbonate-based, and ionic liquid-based electrolytes. And then we move on to the advances in solid systems, including polymer and non-polymer electrolytes. Finally, the opportunities and perspectives for future research in both the liquid and solid Li–S batteries are presented.

Developments of Electrolyte Systems for Lithium-Sulfur Batteries: A Review

Directory of Open Access Journals (Sweden)

Zhan eLin

2015-02-01

Full Text Available With a theoretical specific energy 5 times higher than that of lithium-ion (Li-ion batteries (2,600 vs. ~500 Wh kg-1, lithium-sulfur (Li-S batteries have been considered as one of the most promising energy storage systems for the electrification of vehicles. However, both the polysulfide shuttle effects of the sulfur cathode and dendrite formation of the lithium anode are still key limitations to practical use of traditional Li-S batteries. In this review, we focus on the recent developments in electrolyte systems. First we start with a brief discussion on fundamentals of Li-S batteries and key challenges associated with traditional liquid cells. We then introduce the most recent progresses in liquid systems, including ether-based, carbonate-based, and ionic liquid-based electrolytes. And then we move on to the advances in solid systems, including polymer and non-polymer electrolytes. Finally, the opportunities and perspectives for future research in both the liquid and solid Li-S batteries are presented.

Sparingly Solvating Electrolytes for High Energy Density Lithium-Sulfur Batteries

Energy Technology Data Exchange (ETDEWEB)

Cheng, Lei; Curtiss, Larry A.; Zavadil, Kevin R.; Gewirth, Andrew A.; Shao, Yuyan; Gallagher, Kevin

2016-07-11

Moving to lighter and less expensive battery chemistries compared to lithium-ion requires the control of energy storage mechanisms based on chemical transformations rather than intercalation. Lithium sulfur (Li/S) has tremendous theoretical specific energy, but contemporary approaches to control this solution-mediated, precipitation-dissolution chemistry requires using large excesses of electrolyte to fully solubilize the polysulfide intermediate. Achieving reversible electrochemistry under lean electrolyte operation is the only path for Li/S to move beyond niche applications to potentially transformational performance. An emerging topic for Li/S research is the use of sparingly solvating electrolytes and the creation of design rules for discovering new electrolyte systems that fundamentally decouple electrolyte volume from reaction mechanism. This perspective presents an outlook for sparingly solvating electrolytes as the key path forward for longer-lived, high-energy density Li/S batteries including an overview of this promising new concept and some strategies for accomplishing it.

First-principles molecular dynamics simulation study on electrolytes for use in redox flow battery

Science.gov (United States)

Choe, Yoong-Kee; Tsuchida, Eiji; Tokuda, Kazuya; Ootsuka, Jun; Saito, Yoshihiro; Masuno, Atsunobu; Inoue, Hiroyuki

2017-11-01

Results of first-principles molecular dynamics simulations carried out to investigate structural aspects of electrolytes for use in a redox flow battery are reported. The electrolytes studied here are aqueous sulfuric acid solutions where its property is of importance for dissolving redox couples in redox flow battery. The simulation results indicate that structural features of the acid solutions depend on the concentration of sulfuric acid. Such dependency arises from increase of proton dissociation from sulfuric acid.

Danburite decomposition by sulfuric acid

International Nuclear Information System (INIS)

Mirsaidov, U.; Mamatov, E.D.; Ashurov, N.A.

2011-01-01

Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by sulfuric acid. The process of decomposition of danburite concentrate by sulfuric acid was studied. The chemical nature of decomposition process of boron containing ore was determined. The influence of temperature on the rate of extraction of boron and iron oxides was defined. The dependence of decomposition of boron and iron oxides on process duration, dosage of H 2 SO 4 , acid concentration and size of danburite particles was determined. The kinetics of danburite decomposition by sulfuric acid was studied as well. The apparent activation energy of the process of danburite decomposition by sulfuric acid was calculated. The flowsheet of danburite processing by sulfuric acid was elaborated.

Mechanism of Early Stage Corrosion for Boric-sulfuric Acid Anodized 2A97 Al-Cu-Li Alloy Under Tropical Marine Atmosphere

Directory of Open Access Journals (Sweden)

LUO Chen

2016-09-01

Full Text Available Optical microscopy(OM, scanning electron microscopy(SEM, EDX and EIS combined with ultramicrotomy were employed to investigate the micro morphology, chemical composition and electrochemical properties of anodized 2A97 Al-Cu-Li alloy before and after atmospheric corrosion. The results show that when electrolytes containing combinations of tartaric-sulfuric or boric-sulfuric acid are used to grow the films at different temperatures, boric acid addition and higher temperature allow for higher current density that speeds up the film growth. The pore geometry and structure is similar for different electrolytes. Dispersive dark rusty spots composed of O, Al, Cl, Cu are present on the boric-sulfuric acid anodized specimen after exposure in tropical marine atmosphere for 1 month. Deposition of white corrosion product is found on the specimen surface as well. Severe pitting occurs and develops deeply into the alloy substrate after elongated outdoor exposure. Corrosion propagation is associated with θ-phase particles.

46 CFR 153.1046 - Sulfuric acid.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

46 CFR 151.50-21 - Sulfuric acid.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid of concentration of 77.5 percent (1.7019 specific gravity) (59.8...

21 CFR 582.1095 - Sulfuric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is generally...

Electrolyte for stable cycling of high-energy lithium sulfur redox flow batteries

Science.gov (United States)

Xiao, Jie; Liu, Jun; Pan, Huilin; Henderson, Wesley A.

2018-04-24

A device comprising: a lithium sulfur redox flow battery comprising an electrolyte composition comprising: (i) a dissolved Li2Sx electroactive salt, wherein x.gtoreq.4; (ii) a solvent selected from dimethyl sulfoxide, tetrahydrofuran, or a mixture thereof; and (iii) a supporting salt at a concentration of at least 2 M, as measured by moles of supporting salt divided by the volume of the solvent without considering the volume change of the electrolyte after dissolving the supporting salt.

21 CFR 184.1095 - Sulfuric acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9), also...

Electrolyte for stable cycling of high-energy lithium sulfur redox flow batteries

Energy Technology Data Exchange (ETDEWEB)

Xiao, Jie; Liu, Jun; Pan, Huilin; Henderson, Wesley A.

2018-04-24

A device comprising: a lithium sulfur redox flow battery comprising an electrolyte composition comprising: (i) a dissolved Li₂S_x electroactive salt, wherein x.gtoreq.4; (ii) a solvent selected from dimethyl sulfoxide, tetrahydrofuran, or a mixture thereof; and (iii) a supporting salt at a concentration of at least 2 M, as measured by moles of supporting salt divided by the volume of the solvent without considering the volume change of the electrolyte after dissolving the supporting salt.

Electrolyte Additives for Phosphoric Acid Fuel Cells

DEFF Research Database (Denmark)

Gang, Xiao; Hjuler, H.A.; Olsen, C.A.

1993-01-01

, as a fuel-cell performance with the modified electrolytes. Specific conductivity measurements of some of the modified phosphoric acid electrolytes are reported. At a given temperature, the conductivity of the C4F9SO3K-modified electrolyte decreases with an increasing amount of the additive; the conductivity...... of the remains at the same value as the conductivity of the pure phosphoric acid. At a given composition, the conductivity of any modified electrolyte increases with temperature. We conclude that the improved cell performance for modified electrolytes is not due to any increase in conductivity.......Electrochemical characteristics of a series of modified phosphoric acid electrolytes containing fluorinated car on compounds and silicone fluids as additives are presented. When used in phosphoric acid fuel cells, the modified electrolytes improve the performance due to the enhanced oxygen...

Extraction of manganese from electrolytic manganese residue by bioleaching.

Science.gov (United States)

Xin, Baoping; Chen, Bing; Duan, Ning; Zhou, Changbo

2011-01-01

Extraction of manganese from electrolytic manganese residues using bioleaching was investigated in this paper. The maximum extraction efficiency of Mn was 93% by sulfur-oxidizing bacteria at 4.0 g/l sulfur after bioleaching of 9days, while the maximum extraction efficiency of Mn was 81% by pyrite-leaching bacteria at 4.0 g/l pyrite. The series bioleaching first by sulfur-oxidizing bacteria and followed by pyrite-leaching bacteria evidently promoted the extraction of manganese, witnessing the maximum extraction efficiency of 98.1%. In the case of sulfur-oxidizing bacteria, the strong dissolution of bio-generated sulfuric acid resulted in extraction of soluble Mn2+, while both the Fe2+ catalyzed reduction of Mn4+ and weak acidic dissolution of Mn2+ accounted for the extraction of manganese with pyrite-leaching bacteria. The chemical simulation of bioleaching process further confirmed that the acid dissolution of Mn2+ and Fe2+ catalyzed reduction of Mn4+ were the bioleaching mechanisms involved for Mn extraction from electrolytic manganese residues. Copyright © 2010 Elsevier Ltd. All rights reserved.

Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment

Science.gov (United States)

Marković, Radmila; Stevanović, Jasmina; Avramović, Ljiljana; Nedeljković, Dragutin; Jugović, Branimir; Stajić-Trošić, Jasna; Gvozdenović, Milica

2012-12-01

The aim of this study is synthesis of copper-sulfate pentahydrate from the waste sulfuric acid solution-mother liquor generated during the regeneration process of copper bleed solution. Copper is removed from the mother liquor solution in the process of the electrolytic treatment using the insoluble lead anodes alloyed with 6 mass pct of antimony on the industrial-scale equipment. As the result of the decopperization process, copper is removed in the form of the cathode sludge and is precipitated at the bottom of the electrolytic cell. By this procedure, the content of copper could be reduced to the 20 mass pct of the initial value. Chemical characterization of the sludge has shown that it contains about 90 mass pct of copper. During the decopperization process, the very strong poison, arsine, can be formed, and the process is in that case terminated. The copper leaching degree of 82 mass pct is obtained using H2SO4 aqueous solution with the oxygen addition during the cathode sludge chemical treatment at 80 °C ± 5 °C. Obtained copper salt satisfies the requirements of the Serbian Standard for Pesticide, SRPS H.P1. 058. Therefore, the treatment of waste sulfuric acid solutions is of great economic and environmental interest.

Method of electrolytically decontaminating of radioactive metal wastes

International Nuclear Information System (INIS)

Oonuma, Tsutomu; Tanaka, Akio; Yamadera, Toshio.

1985-01-01

Purpose: To significantly reduce the volume of secondary wastes by separating from electrolytes metal ions containing radioactive metal ions dissolved therein in the form of elemental metals of a reduced volume with ease, as well as regenerating the electrolytes for re-use. Method: Contaminated portions at the surface of the radioactive metal wastes are dissolved in electrolytes and, when the metal ion concentration in the electrolytes reaches a predetermined level, the electrolytes are introduced to an acid recovery step and an electrodeposition step. The recovered acid is re-used as the electrolytes, while dissolved metal ions containing radioactive metal ions are deposited as elemental metals in the electrodeposition step. The electrolytes usable herein include those acids easily forming stable complex compounds with the metals or those not forming hydroxides of the contaminated metals. Combination of sodium sulfate and sulfuric acid, sodium chloride and hydrochloride or the like is preferred. (Kamimura, M.)

Dew point of gases with low sulfuric acid content

Energy Technology Data Exchange (ETDEWEB)

Fieg, J.

1981-07-01

Discusses control of air pollution caused by sulfur compounds in solid fuels during combustion. Excessive amount of oxygen during combustion leads to formation of sulfur trioxide. Sulfur trioxide reacts with water vapor and forms sulfuric acid. Chemical reactions which lead to formation of sulfuric acid are described. Conditions for sulfuric acid condensation are analyzed. Several methods for determining dew point of flue gases with low sulfuric acid content are reviewed: methods based on determination of electric conductivity of condensed sulfuric acid (Francis, Cheney, Kiyoure), method based on determination of sulfuric acid concentration in the gaseous phase and in the liquid phase after cooling (Lee, Lisle and Sensenbaugh, Ross and Goksoyr). (26 refs.) (In Polish)

Block Copolymer Electrolytes: Thermodynamics, Ion Transport, and Use in Solid- State Lithium/Sulfur Cells

Science.gov (United States)

Teran, Alexander Andrew

Nanostructured block copolymer electrolytes containing an ion-conducting block and a modulus-strengthening block are of interest for applications in solid-state lithium metal batteries. These materials can self-assemble into well-defined microstructures, creating conducting channels that facilitate ion transport. The overall objective of this dissertation is to gain a better understanding of the behavior of salt-containing block copolymers, and evaluate their potential for use in solid-state lithium/sulfur batteries. Anionically synthesized polystyrene-b-poly(ethylene oxide) (SEO) copolymers doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt were used as a model system. This thesis investigates the model system on several levels: from fundamental thermodynamic studies to bulk characterization and finally device assembly and testing. First, the thermodynamics of neat and salt-containing block copolymers was studied. The addition of salt to these materials is necessary to make them conductive, however even small amounts of salt can have significant effects on their phase behavior, and consequently their iontransport and mechanical properties. As a result, the effect of salt addition on block copolymer thermodynamics has been the subject of significant interest over the last decade. A comprehensive study of the thermodynamics of block copolymer/salt mixtures over a wide range of molecular weights, compositions, salt concentrations and temperatures was conducted. Next, the effect of molecular weight on ion transport in both homopolymer and copolymer electrolytes were studied over a wide range of chain lengths. Homopolymer electrolytes show an inverse relationship between conductivity and chain length, with a plateau in the infinite molecular weight limit. This is due to the presence of two mechanisms of ion conduction in homopolymers; the first mechanism is a result of the segmental motion of the chains surrounding the salt ions, 2 creating a liquid

Molecular simulations of electrolyte structure and dynamics in lithium-sulfur battery solvents

Science.gov (United States)

Park, Chanbum; Kanduč, Matej; Chudoba, Richard; Ronneburg, Arne; Risse, Sebastian; Ballauff, Matthias; Dzubiella, Joachim

2018-01-01

The performance of modern lithium-sulfur (Li/S) battery systems critically depends on the electrolyte and solvent compositions. For fundamental molecular insights and rational guidance of experimental developments, efficient and sufficiently accurate molecular simulations are thus in urgent need. Here, we construct a molecular dynamics (MD) computer simulation model of representative state-of-the art electrolyte-solvent systems for Li/S batteries constituted by lithium-bis(trifluoromethane)sulfonimide (LiTFSI) and LiNO3 electrolytes in mixtures of the organic solvents 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL). We benchmark and verify our simulations by comparing structural and dynamic features with various available experimental reference systems and demonstrate their applicability for a wide range of electrolyte-solvent compositions. For the state-of-the-art battery solvent, we finally calculate and discuss the detailed composition of the first lithium solvation shell, the temperature dependence of lithium diffusion, as well as the electrolyte conductivities and lithium transference numbers. Our model will serve as a basis for efficient future predictions of electrolyte structure and transport in complex electrode confinements for the optimization of modern Li/S batteries (and related devices).

Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment

OpenAIRE

Marković, Radmila; Stevanović, Jasmina; Avramović, Ljiljana; Nedeljković, Dragutin; Jugović, Branimir; Stajić Trošić, Jasna; Gvozdenović, Milica M.

2012-01-01

The aim of this study is synthesis of copper-sulfate pentahydrate from the waste sulfuric acid solution-mother liquor generated during the regeneration process of copper bleed solution. Copper is removed from the mother liquor solution in the process of the electrolytic treatment using the insoluble lead anodes alloyed with 6 mass pct of antimony on the industrial-scale equipment. As the result of the decopperization process, copper is removed in the form of the cathode sludge and is precipit...

The physicochemical properties of a [DEME][TFSI] ionic liquid-based electrolyte and their influence on the performance of lithium–sulfur batteries

International Nuclear Information System (INIS)

Drvarič Talian, Sara; Bešter-Rogač, Marija; Dominko, Robert

2017-01-01

Electrolyte choice is an important decision on the quest for higher-energy batteries. Besides general guidelines on the required properties of an electrolyte suitable for use in lithium–sulfur batteries, the influence of more specific physicochemical properties on its characteristics is not well understood. For this purpose, binary mixtures based on the [DEME][TFSI] and dioxolane electrolyte system for lithium–sulfur batteries was investigated in this work. Selected physicochemical properties were determined for different mixtures of solvents and lithium salt concentrations. All the electrolytes prepared were also tested in the lithium–sulfur battery system. The capacity, Coulombic efficiency, overpotentials and impedance spectra were analyzed and a connection between them and the determined electrolyte properties elucidated. We show that the electrolyte's conductivity does not have a direct connection to any of the battery system properties measured. The highest specific capacities were obtained with batteries compromising 1.0 M LiTFSI and the highest ratio of dioxolane in the binary solvent mixture. On the other hand, the best Coulombic efficiencies were obtained with batteries having high ratios of ionic liquid. Resistance and overpotential are connected parameters and are a function of the ionic liquid content. None of the monitored parameters prevail, since the best electrochemical performance in terms of specific capacity and stability was obtained with the 1.0 M LiTFSI in X[DEME][TFSI] = 0.199 electrolyte.

Digestion of Bangka monazite with sulfuric acid

International Nuclear Information System (INIS)

Riesna Prassanti

2012-01-01

Technology of Bangka monazite processing with alkaline method has been mastered by PPGN BATAN with the product in the form of RE (Rare Earth) which is contain U < 2 ppm and Th 12 - 16 ppm. Hence, as comparator, the research of Bangka monazite processing with acid method using sulfuric acid has been done. The aim of this research is to obtain the optimal condition of Bangka monazite's digestion using sulfuric acid so that all elements contained in the monazite that are U, Th, RE, PO 4 dissolved as much as possible. The research parameter's arc monazite particle's size, sulfuric acid consumption (weight ratio of monazite ore : sulfuric acid), digestion temperature, digestion time and consumption of wash water. The results showed that the optimal conditions of digestion are 250+ 325 mesh of monazite particle's size, 1 : 2.5 of weight ratio of monazite ore: sulfuric acid, 190°C of digestion temperature, 3 hours of digestion time and 8 times of weight monazite's feed of wash water with the recovery of digested U = 99.90 %, Th = 99.44 %, RE = 98.64 % and PO 4 = 99.88 %. (author)

Accidents with sulfuric acid

Directory of Open Access Journals (Sweden)

Rajković Miloš B.

2006-01-01

Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

Analysis of sulfur-iodine thermochemical cycle for solar hydrogen production. Part 1: decomposition of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Huang, Cunping; T-Raissi, Ali [Central Florida Univ., Florida Solar Energy Center, Cocoa, FL (United States)

2005-05-01

The sulfur-iodine (S-I) thermochemical water splitting cycle is one of the most studied cycles for hydrogen (H{sub 2}) production. S-I cycle consists of four sections: (I) acid production and separation and oxygen purification, (II) sulfuric acid concentration and decomposition, (III) hydroiodic acid (HI) concentration, and (IV) HI decomposition and H{sub 2} purification. Section II of the cycle is an endothermic reaction driven by the heat input from a high temperature source. Analysis of the S-I cycle in the past thirty years have been focused mostly on the utilization of nuclear power as the high temperature heat source for the sulfuric acid decomposition step. Thermodynamic as well as kinetic considerations indicate that both the extent and rate of sulfuric acid decomposition can be improved at very high temperatures (in excess of 1000 deg C) available only from solar concentrators. The beneficial effect of high temperature solar heat for decomposition of sulfuric acid in the S-I cycle is described in this paper. We used Aspen Technologies' HYSYS chemical process simulator (CPS) to develop flowsheets for sulfuric acid (H{sub 2}SO{sub 4}) decomposition that include all mass and heat balances. Based on the HYSYS analyses, two new process flowsheets were developed. These new sulfuric acid decomposition processes are simpler and more stable than previous processes and yield higher conversion efficiencies for the sulfuric acid decomposition and sulfur dioxide and oxygen formation. (Author)

All-solid-state lithium-sulfur battery based on a nanoconfined LiBH4 electrolyte

DEFF Research Database (Denmark)

Das, Supti; Ngene, Peter; Norby, Poul

2016-01-01

In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4 in mesoporous silica as solid electrolytes. The nano-confined LiBH4 has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport...... number (t+ = 0.96), close to unity, demonstrates a purely cationic conductor. The electrolyte has an excellent stability against lithium metal. The behavior of the batteries is studied by cyclic voltammetry and repeated charge/discharge cycles in galvanostatic conditions. The batteries show very good...

Lanthanum Nitrate As Electrolyte Additive To Stabilize the Surface Morphology of Lithium Anode for Lithium-Sulfur Battery.

Science.gov (United States)

Liu, Sheng; Li, Guo-Ran; Gao, Xue-Ping

2016-03-01

Lithium-sulfur (Li-S) battery is regarded as one of the most promising candidates beyond conventional lithium ion batteries. However, the instability of the metallic lithium anode during lithium electrochemical dissolution/deposition is still a major barrier for the practical application of Li-S battery. In this work, lanthanum nitrate, as electrolyte additive, is introduced into Li-S battery to stabilize the surface of lithium anode. By introducing lanthanum nitrate into electrolyte, a composite passivation film of lanthanum/lithium sulfides can be formed on metallic lithium anode, which is beneficial to decrease the reducibility of metallic lithium and slow down the electrochemical dissolution/deposition reaction on lithium anode for stabilizing the surface morphology of metallic Li anode in lithium-sulfur battery. Meanwhile, the cycle stability of the fabricated Li-S cell is improved by introducing lanthanum nitrate into electrolyte. Apparently, lanthanum nitrate is an effective additive for the protection of lithium anode and the cycling stability of Li-S battery.

Hydrogenation of gold-related levels in silicon by electrolytic doping

International Nuclear Information System (INIS)

Pearton, S.J.; Hansen, W.L.; Haller, E.E.; Kahn, J.M.

1984-01-01

The deep gold-related donor and acceptor levels in silicon have been neutralized to several μm depth by introducing atomic hydrogen using an electrolytic method. Using phosphoric or sulfuric acid as the electrolyte, it is possible to dope the crystalline silicon with hydrogen at elevated temperatures (200--280 0 C) allowing direct comparison with other means of introduction, such as hydrogen plasma exposure. We find the electrolytic method is not as efficient as plasma treatment for the same conditions, possibly due to oxide formation during the immersion in the acid

All-Solid-State Lithium-Sulfur Battery based on a nanoconfined LiBH 4 Electrolyte

NARCIS (Netherlands)

Das, Supti; Ngene, Peter; Norby, Poul; Vegge, Tejs; de Jongh, P.E.; Blanchard, Didier

2016-01-01

In this work we characterize all-solid-state lithium-sulfur batteries based on nano-confined LiBH4in mesoporous silica as solid electrolytes. The nano-confined LiBH4has fast ionic lithium conductivity at room temperature, 0.1 mScm-1, negligible electronic conductivity and its cationic transport

Method of recovering phosphoric acid type decontaminating electrolytes by electrodeposition

International Nuclear Information System (INIS)

Sasaki, Takashi; Wada, Koichi; Kobayashi, Toshio.

1985-01-01

Purpose: To recoving phosphoric acid type highly concentrated decontaminating liquid used for the electrolytic decontamination of contaminated equipments, components, etc in nuclear power plants or the like through electrodeposition by diaphragm electrolysis. Method: Before supplying phosphoric acid decontaminating liquid at high concentration used in the electrolytic decontaminating step to an electrodeposition recovering tank, phosphoric acid in the decontaminating electrolyte is extracted with solvents and decomposed liquid extracts (electrolyte reduced with the phosphoric acid component) are supplied to the cathode chamber of the electrodeposition recovering tank, where phosphoric acid is back-extracted with water from the solvents after extraction of phosphoric acid. Then, the back-extracted liquids (aqueous phosphoric acid solution scarcely containing metal ions) are sent to the anode chamber of the electrodeposition recovering tank. Metal ions in the liquid are captured by electrodeposition in the cathode chamber, as well as phosphoric acid in the liquids is concentrated to the initial concentration of the electrolyte in the anode chamber for reuse as the decontaminating electrolyte. As the phosphoric acid extracting agent used in the electrodeposition recovering step for the decontaminating electrolyte, water-insoluble and non-combustible tributyl phosphate (TBP) is most effective. (Horiuchi, T.)

Mathematical modeling of the lithium, thionyl chloride static cell. I. Neutral electrolyte. II - Acid electrolyte

Energy Technology Data Exchange (ETDEWEB)

Tsaur, K.C.; Pollard, R.

1984-05-01

Mathematical models are presented for a Li-LiAlCl4/SOCl2-C static cell with neutral electrolyte and a Li/SOCl2-C static cell with acid electrolyte. The model for the Li-LiAlCl4/SOCl2-C cell with neutral solution predicts that high internal resistance can develop in the positive electrode as a result of low local porosities which are, in turn, caused by large-volume, solid reaction products. Consequently, the maximum usable cell capacity is dictated by the nonuniformity of the reaction distribution at the front of the positive electrode. In many respects, a cell with acid electrolyte can be regarded as a combination of an equivalent neutral electrolyte system and an acid reservoir. The model for the Li/SOCl2 cell suggests that the cell life depends primarily on the quantity of acid added to the electrolyte. 58 references.

Mathematical modeling of the lithium, thionyl chloride static cell. I - Neutral electrolyte. II - Acid electrolyte

Science.gov (United States)

Tsaur, K.-C.; Pollard, R.

1984-05-01

Mathematical models are presented for a Li-LiAlCl4/SOCl2-C static cell with neutral electrolyte and a Li/SOCl2-C static cell with acid electrolyte. The model for the Li-LiAlCl4/SOCl2-C cell with neutral solution predicts that high internal resistance can develop in the positive electrode as a result of low local porosities which are, in turn, caused by large-volume, solid reaction products. Consequently, the maximum usable cell capacity is dictated by the nonuniformity of the reaction distribution at the front of the positive electrode. In many respects, a cell with acid electrolyte can be regarded as a combination of an equivalent neutral electrolyte system and an acid reservoir. The model for the Li/SOCl2 cell suggests that the cell life depends primarily on the quantity of acid added to the electrolyte.

Electrolytes for methanol-air fuel cells. I. The performance of methanol electro-oxidation catalysts in sulphuric acid and phosphoric acid electrolytes

Energy Technology Data Exchange (ETDEWEB)

Andrew, M.R.; McNicol, B.D.; Short, R.T.; Drury, J.S.

1977-03-01

Phosphoric acid and sulphuric acid have been compared as potential electrolytes for methanol-air fuel cells. The performances of typical electro-oxidation catalysts were measured in both electrolytes over a range of concentrations. With all catalysts the activity falls with increasing acid concentration. While this is to some extent due to the decrease in water activity at higher concentrations it seems that with both acids there is significant poisoning of the catalyst. The results can be explained for both electrolytes by assuming that adsorption of undissociated acid poisons the catalyst surfaces and that the reaction rate on the poisoned surfaces is proportional to the water activity.

The effect of water-containing electrolyte on lithium-sulfur batteries

Science.gov (United States)

Wu, Heng-Liang; Haasch, Richard T.; Perdue, Brian R.; Apblett, Christopher A.; Gewirth, Andrew A.

2017-11-01

Dissolved polysulfides, formed during Li-S battery operation, freely migrate and react with both the Li anode and the sulfur cathode. These soluble polysulfides shuttle between the anode and cathode - the so-called shuttle effect - resulting in an infinite recharge process and poor Columbic efficiency. In this study, water present as an additive in the Li-S battery electrolyte is found to reduce the shuttle effect in Li-S batteries. Batteries where water content was below 50 ppm exhibited a substantial shuttle effect and low charge capacity. Alternatively, addition of 250 ppm water led to stable charge/discharge behavior with high Coulombic efficiency. XPS results show that H2O addition results in the formation of solid electrolyte interphase (SEI) film with more LiOH on Li anode which protects the Li anode from the polysulfides. Batteries cycled without water result in a SEI film with more Li2CO3 likely formed by direct contact between the Li metal and the solvent. Intermediate quantities of H2O in the electrolyte result in high cycle efficiency for the first few cycles which then rapidly decays. This suggests that H2O is consumed during battery cycling, likely by interaction with freshly exposed Li metal formed during Li deposition.

In-situ Fabrication of a Freestanding Acrylate-based Hierarchical Electrolyte for Lithium-sulfur Batteries

International Nuclear Information System (INIS)

Liu, M.; Jiang, H.R.; Ren, Y.X.; Zhou, D.; Kang, F.Y.; Zhao, T.S.

2016-01-01

Graphical abstract: We present a freestanding acrylate-based hierarchical electrolyte. This quasi-solid electrolyte is assembled by in-situ gelation of a pentaerythritol tetraacrylate (PETEA)-based gel polymer electrolyte (GPE) into a polymethyl methacrylate (PMMA)-based electrospun network. The prepared polymer battery renders a suppressed shuttle effect and much enhanced cycle life. - Highlights: • A freestanding Acrylate-based Hierarchical Electrolyte was in-situ crafted. • The high conductivity is due to strong uptake ability and elimination of separator. • The polymer battery renders a superior high rate capability and excellent retention. • First-principle calculations prove anchoring ability of ester functional groups. • Cell modeling shows geometric design effectively suppresses polysulfide flux. - Abstract: A number of methods have been attempted to suppress the shuttle effect in lithium-sulfur (Li-S) batteries to improve battery performance. Conventional methods, however, reduce the ionic conductivity, sacrifice the overall energy density and increase the cost of production. Here, we report a facile synthesis of an acrylate-based hierarchical electrolyte (AHE). This quasi-solid electrolyte is assembled by in-situ gelation of a pentaerythritol tetraacrylate (PETEA)-based gel polymer electrolyte (GPE) into a polymethyl methacrylate (PMMA)-based electrospun network. The structural similarity and synergetic compatibility between the electrospun network and GPE provide the AHE an ester-rich robust structure with a high ionic conductivity of 1.02 × 10 −3 S cm −1 due to the strong uptake ability and the elimination of commercial separator. The S/AHE/Li polymer battery also renders a high rate capability of 645 mAh g −1 at 3C, while maintaining excellent retention at both high and low current densities (80.3% after 500 cycles at 0.3C and 91.9% after 500 cycles at 3C). First-principle calculations reveal that the reduced shuttle effect can be

Extraction of sulfuric acid with TOPO

International Nuclear Information System (INIS)

Shuyun, Xue; Yonghui, Yang; Yanzhao, Yang; Sixiu, Sun; Borong, Bao

1998-01-01

A study on solvent extraction of sulfuric acid by tri-octylphosphine oxide (TOPO) in n-heptane has been made. Extraction coefficients of H 2 SO 4 as a function of H 2 SO 4 concentration in aqueous phase, and extractant concentrations in organic phase have been studied. The composition of extracted species, equilibrium constants of extraction reaction have been evaluated. These results are important for interpreting extraction equilibrium data of uranium(VI) or other metal ions with TOPO in sulfuric acid media. (author)

Lithium/sulfur batteries with mixed liquid electrolytes based on ethyl 1,1,2,2-tetrafluoroethyl ether

International Nuclear Information System (INIS)

Lu, Hai; Zhang, Kai; Yuan, Yan; Qin, Furong; Zhang, Zhian; Lai, Yanqing; Liu, Yexiang

2015-01-01

Highlights: • Electrolyte based on fluorinated ether of ETFE is used in Li/S battery. • ETFE improves cycling, rate and self-discharging performances of Li/S battery. • Surface film on Li anode modified by ETFE inhibits the shuttle of polysulfides. - Abstract: Fluorinated ether of ethyl 1,1,2,2-tetrafluoroethyl ether (ETFE) was selected as electrolyte solvent for lithium/sulfur battery, and the influence of ETFE in electrolyte on cell properties was first investigated. The enhanced stability of electrolyte/anode interface and improved electrochemical performances (cycling, rate and self-discharging) of the Li/S cell are presented by using ETFE-containing electrolyte, especially for complete replacement of tetraethylene glycol dimethyl ether (TEGDME) by ETFE in combine with 1,3-dioxolane (DOL). It is found that ETFE plays a key role in modifying the surface composition and structure of the metallic Li, forming a strengthened protective film on the anode during cycling. Besides, ETFE is considered to decrease the dissolution of polysulfides in the electrolyte. These factors together restrict the contact and reaction between polysulfides and Li anode

Self-assembled peptides for coating of active sulfur nanoparticles in lithium–sulfur battery

International Nuclear Information System (INIS)

Jewel, Yead; Yoo, Kisoo; Liu, Jin; Dutta, Prashanta

2016-01-01

Development of lithium–sulfur (Li–S) battery is hindered by poor cyclability due to the loss of sulfur, although Li–S battery can provide high energy density. Coating of sulfur nanoparticles can help maintain active sulfur in the cathode of Li–S battery, and hence increase the cyclability. Among myriad of coating materials, synthetic peptides are very attractive because of their spontaneous self-assembly as well as electrical conductive characteristics. In this study, we explored the use of various synthetic peptides as a coating material for sulfur nanoparticles. Atomistic simulations were carried out to identify optimal peptide structure and density for coating sulfur nanoparticles. Three different peptide models, poly-proline, poly(leucine–lysine) and poly-histidine, are selected for this study based on their peptide–peptide and peptide-sulfur interactions. Simulation results show that both poly-proline and poly(leucine–lysine) can form self-assembled coating on sulfur nanoparticles (2–20 nm) in pyrrolidinone, a commonly used solvent for cathode slurry. We also studied the structural integrity of these synthetic peptides in organic [dioxolane (DOL) and dimethoxyethane (DME)] electrolyte used in Li–S battery. Both peptides show stable structures in organic electrolyte (DOL/DME) used in Li–S battery. Furthermore, the dissolution of sulfur molecules in organic electrolyte is investigated in the absence and presence of these peptide coatings. It was found that only poly(leucine–lysine)-based peptide can most effectively suppress the sulfur loss in electrolyte, suggesting its potential applications in Li–S battery as a coating material.Graphical abstract

The corrosion protection of several aluminum alloys by chromic acid and sulfuric acid anodizing

Science.gov (United States)

Danford, M. D.

1994-01-01

The corrosion protection afforded 7075-T6, 7075-T3, 6061-T6, and 2024-T3 aluminum alloys by chromic acid and sulfuric acid anodizing was examined using electrochemical techniques. From these studies, it is concluded that sulfuric acid anodizing provides superior corrosion protection compared to chromic acid anodizing.

Composite electrolytes composed of Cs-substituted phosphotungstic acid and sulfonated poly(ether-ether ketone) for fuel cell systems

Energy Technology Data Exchange (ETDEWEB)

Oh, Song-Yul, E-mail: ms089203@tutms.tut.ac.jp [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Yoshida, Toshihiro; Kawamura, Go [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Muto, Hiroyuki [Department of Materials Science and Engineering, Kurume National College of Technology, 1-1-1 Komorino, Kurume, Fukuoka 830-8555 (Japan); Sakai, Mototsugu [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Matsuda, Atsunori, E-mail: matsuda@tutms.tut.ac.jp [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)

2010-10-15

Composite electrolytes composed of cesium hydrogen sulfate containing phosphotungstic acids (CsHSO{sub 4}-H{sub 3}PW{sub 12}O{sub 40}) and sulfonated poly(ether-ether ketone) (SPEEK) were prepared by casting the corresponding precursor for application in fuel cells. Partially Cs-substituted phosphotungstic acids (Cs{sub x}H{sub 3-x}PW{sub 12}O{sub 40}) were formed in the CsHSO{sub 4}-H{sub 3}PW{sub 12}O{sub 40} system by mechanochemical treatment. SPEEK was prepared from PEEK by sulfonation using concentrated sulfuric acid. Flexible composite electrolytes were obtained and their electrochemical properties were markedly improved with the addition of Cs{sub x}H{sub 3-x}PW{sub 12}O{sub 40}, into the SPEEK matrix. A maximum power density of 213 mW cm{sup -2} was obtained from the single cell test for 50H{sub 3}PW{sub 12}O{sub 40}-50CsHSO{sub 4} in SPEEK (1/5 by weight) composite electrolyte at 80 deg. C and at 80 RH%. Electrochemical properties and transmission electron microscopy (TEM) results suggest that three-dimensional cluster particles were formed and homogeneously distributed in the SPEEK matrix. The mechanochemically synthesized Cs{sub x}H{sub 3-x}PW{sub 12}O{sub 40} incorporated into the SPEEK matrix increased the number of protonate sites in the electrolyte. The composite electrolytes were successfully formed with Cs{sub x}H{sub 3-x}PW{sub 12}O{sub 40}, which consist of hydrogen bonding between surface of inorganic solid acids and not only -HSO{sub 4}{sup -} dissociated from CsHSO{sub 4} but also -SO{sub 3}H groups in the SPEEK.

Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

Science.gov (United States)

Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

1997-01-01

Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

Molecular interaction of pinic acid with sulfuric acid

DEFF Research Database (Denmark)

Elm, Jonas; Kurtén, Theo; Bilde, Merete

2014-01-01

We investigate the molecular interactions between the semivolatile α-pinene oxidation product pinic acid and sulfuric acid using computational methods. The stepwise Gibbs free energies of formation have been calculated utilizing the M06-2X functional, and the stability of the clusters is evaluated...... cluster. The involvement of more than one pinic acid molecule in a single cluster is observed to lead to the formation of favorable (pinic acid)2(H2SO4) and (pinic acid)2(H2SO4)2 clusters. The identified most favorable growth paths starting from a single pinic acid molecule lead to closed structures...

Proton conductivity and fuel cell property of composite electrolyte consisting of Cs-substituted heteropoly acids and sulfonated poly(ether-ether ketone)

Energy Technology Data Exchange (ETDEWEB)

Oh, S.Y.; Yoshida, T.; Kawamura, G.; Sakai, M.; Matsuda, A. [Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Muto, H. [Department of Materials Science and Engineering, Kurume National College of Technology, 1-1-1 Komorino, Kurume, Fukuoka 830-8555 (Japan)

2010-09-15

Inorganic-organic composite electrolytes were fabricated from partially Cs{sup +}-substituted heteropoly acids (Cs-HPAs) and sulfonated poly(ether-ether ketone) (SPEEK) for application in fuel cells. Heteropoly acids, such as phosphotungstic acid (H{sub 3}PW{sub 12}O{sub 40}:WPA), and silicotungstic acid (H{sub 4}SiW{sub 12}O{sub 40}:WSiA), were mechanochemically treated with cesium hydrogen sulfate (CsHSO{sub 4}) to obtain the form of Cs-HPAs. SPEEK was prepared from PEEK by sulfonation using concentrated sulfuric acid. Water durability and surface structure of HPAs were modified by introducing Cs{sup +} into HPAs. Flexible and hot water stable composite electrolytes were obtained, and their electrochemical properties were markedly improved with the addition of Cs-HPAs into the SPEEK matrix. Maximum power densities of 245 and 247 mW cm{sup -2} were obtained for 50WPA.50CsHSO{sub 4} and 50WSiA.50CsHSO{sub 4} in SPEEK (1/5 by weight) composite electrolytes, respectively, from single cell tests at 80 C and 80 RH%. These results suggest that a three-dimensional proton-conductive path was formed among homogeneously distributed Cs-HPAs particles in the SPEEK matrix. The Cs-HPAs incorporated into the SPEEK matrix increased the number of protonate sites in the electrolyte. These observations imply that the mechanochemically synthesized Cs-HPAs, which consist of hydrogen bondings between Cs-HPAs and -HSO{sub 4}{sup -}, dissociated from CsHSO{sub 4}, are promising materials as inorganic fillers in inorganic-organic composite. (author)

Sulfurized carbon: a class of cathode materials for high performance lithium/sulfur batteries

Directory of Open Access Journals (Sweden)

Sheng S. Zhang

2013-12-01

Full Text Available Liquid electrolyte lithium/sulfur (Li/S batteries cannot come into practical applications because of many problems such as low energy efficiency, short cycle life, and fast self-discharge. All these problems are related to the dissolution of lithium polysulfide, a series of sulfur reduction intermediates, in the liquid electrolyte, and resulting parasitic reactions with the Li anode. Covalently binding sulfur onto carbon surface is a solution to completely eliminate the dissolution of lithium polysulfide and make the Li/S battery viable for practical applications. This can be achieved by replacing elemental sulfur with sulfurized carbon as the cathode material. This article reviews the current efforts on this subject and discusses the syntheses, electrochemical properties, and prospects of the sulfurized carbon as a cathode material in the rechargeable Li/S batteries.

Microstructures of the Sulfonic Acid-Functionalized Ionic Liquid/Sulfuric Acid and Their Interactions: A Perspective from the Isobutane Alkylation.

Science.gov (United States)

Zheng, Weizhong; Huang, Chizhou; Sun, Weizhen; Zhao, Ling

2018-02-01

The all-atom force field for concentrated sulfuric acid (98.30 wt %) was developed in this work based on ab initio calculations. The structural and dynamical properties of sulfuric acid and the mixing behaviors of sulfuric acid with ionic liquids (ILs), i.e., SFIL (1-methyl-3-(propyl-3-sulfonate) imidazolium bisulfate ([PSMim][HSO 4 ])) and non-SFIL (1-methyl-3-propyl imidazolium bisulfate ([PMim][HSO 4 ])), were investigated using a molecular dynamics simulation. For sulfuric acid, most H 3 O + ions were found beside HSO 4 - ions, forming a contact ion pair with the HSO 4 - ions, and three-dimensional hydrogen-bonding networks existed in the sulfuric acid. Analyses indicate that both ILs could be miscible with sulfuric acid with a strong exothermic character. The new strong interaction site between the sulfonic acid group of SFIL and an H 2 SO 4 molecule through a strong hydrogen-bonding interaction was observed, which was beneficial to the catalytic activity and stability of the sulfuric acid. This observation is in good agreement with the experimental results that indicate SFILs could enhance the reusability of sulfuric acid for the isobutane alkylation about 4-fold compared to that of non-SFILs. Hopefully this work will provide insights into the screening and designing of new isobutane alkylation catalysts based on sulfuric acid and SFILs.

Electrochemical reduction of sulfur dioxide in sulfolane

Energy Technology Data Exchange (ETDEWEB)

Vorob' ev, A.S.; Gavrilova, A.A.; Kolosnitsyn, V.S.; Nikitin, Yu.E.

1985-09-01

Solutions of sulfur dioxide in aproptic media are promising electrolyte oxidizing agents for chemical current sources with anodes of active metals. This work describes the electrochemical reduction of sulfur dioxide in sulfolane in a lithium halide supporting electrolyte which was investigated by the methods of voltamperometry and chronopotentiometry. The dependence of the current of the cathodic peak on the concentration of the supporting electrolyte salts, sulfur dioxide and water, was studied. On the basis of the data obtained, a hypothesis was advanced on the nature of the limiting step. The investigation showed that at low polarizing current densities, a substantial influence on the reduction of sulfur dioxide in sulfolane in a lithium halide supporting electrolyte is exerted by blockage of the electrode surface by sparingly soluble reaction products.

Safety measures for integrity test apparatus for IS process. Sulfuric acid decomposition section

International Nuclear Information System (INIS)

Noguchi, Hiroki; Kubo, Shinji; Iwatsuki, Jin; Onuki, Kaoru

2013-07-01

Hazardous substances such as sulfuric acid, sulfur dioxide and hydrogen iodide acid are employed in thermochemical Iodine-Sulfur (IS) process. It is necessary to take safety measure against workers and external environments to study experimentally on IS process. Presently we have been conducting to verify the soundness of main components made of engineering material in actual corrosive condition. An integrity test apparatus for the components of sulfuric acid decomposition was set up. We will use the hazardous substances such as sulfuric acid and sulfur dioxide and perform the experiment in pressurized condition in this integrity test. Safety measures for the test apparatus, operation and abnormal situation were considered prior to starting the test. This report summarized the consideration results for the safety measures on the integrity test apparatus for the components of sulfuric acid decomposition. (author)

Mathematical modeling of the lithium, thionyl chloride static cell: acid electrolyte

Energy Technology Data Exchange (ETDEWEB)

Tsaur, K.-C.; Pollard, R.

1984-05-01

A mathematical model for a complete Li/SOCl/sub 2/ static cell with acid electrolyte is presented. Concentrated solution theory is extended to account for the presence of two neutral species in the electrolyte. The effects of initial acid concentration, positive electrode thickness, and galvanostatic discharge rate on cell performance are elucidated. Results are compared with equivalent cells that use a neutral electrolyte.

Contribution to the study of sulfur trioxide formation and determination of the sulfuric acid dew point in boiler plants

Energy Technology Data Exchange (ETDEWEB)

Mueller, H.

1983-11-01

This paper analyzes chemical reaction kinetics of the formation of sulfur trioxide and sulfuric acid in combustion air and flue gas of steam generators. Formulae for sulfuric acid equilibrium reactions according to Wahnschaffe (W. Grimm, 1972) and R. Hasse, H.W. Borgmann (1962) are presented. Theoretical acid dew point, combustion parameters with influence on the dew point temperature and formation of sulfates are further discussed. Sulfur trioxide formation at temperatures above 1,000 C as a non-equilibrium reaction is outlined as another variant of chemical reactions. A graphic evaluation is made of dew point conditions in brown coal dust fired, and heating oil fired steam generators. (11 refs.)

Sulfur amino acid metabolism in doxorubicin-resistant breast cancer cells

International Nuclear Information System (INIS)

Ryu, Chang Seon; Kwak, Hui Chan; Lee, Kye Sook; Kang, Keon Wook; Oh, Soo Jin; Lee, Ki Ho; Kim, Hwan Mook; Ma, Jin Yeul; Kim, Sang Kyum

2011-01-01

Although methionine dependency is a phenotypic characteristic of tumor cells, it remains to be determined whether changes in sulfur amino acid metabolism occur in cancer cells resistant to chemotherapeutic medications. We compared expression/activity of sulfur amino acid metabolizing enzymes and cellular levels of sulfur amino acids and their metabolites between normal MCF-7 cells and doxorubicin-resistant MCF-7 (MCF-7/Adr) cells. The S-adenosylmethionine/S-adenosylhomocysteine ratio, an index of transmethylation potential, in MCF-7/Adr cells decreased to ∼ 10% relative to that in MCF-7 cells, which may have resulted from down-regulation of S-adenosylhomocysteine hydrolase. Expression of homocysteine-clearing enzymes, such as cystathionine beta-synthase, methionine synthase/methylene tetrahydrofolate reductase, and betaine homocysteine methyltransferase, was up-regulated in MCF-7/Adr cells, suggesting that acquiring doxorubicin resistance attenuated methionine-dependence and activated transsulfuration from methionine to cysteine. Homocysteine was similar, which is associated with a balance between the increased expressions of homocysteine-clearing enzymes and decreased extracellular homocysteine. Despite an elevation in cysteine, cellular GSH decreased in MCF-7/Adr cells, which was attributed to over-efflux of GSH into the medium and down-regulation of the GSH synthesis enzyme. Consequently, MCF-7/Adr cells were more sensitive to the oxidative stress induced by bleomycin and menadione than MCF-7 cells. In conclusion, our results suggest that regulating sulfur amino acid metabolism may be a possible therapeutic target for chemoresistant cancer cells. These results warrant further investigations to determine the role of sulfur amino acid metabolism in acquiring anticancer drug resistance in cancer cells using chemical and biological regulators involved in sulfur amino acid metabolism. - Research highlights: → MCF-7/Adr cells showed decreases in cellular GSH

Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

Energy Technology Data Exchange (ETDEWEB)

Huang, B.S., E-mail: yinwenfeng2010@163.com [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Yin, W.F. [College of Mechatronic Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Sang, D.H. [Sheng Li Construction Group International Engineering Department, Shandong, Dongying, 257000 (China); Jiang, Z.Y. [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China)

2012-10-15

Highlights: Black-Right-Pointing-Pointer The corrosion of a carbon-manganese steel and a stainless steel in sulfur and/or naphthenic acid media was investigated. Black-Right-Pointing-Pointer The corrosion rate of the carbon-manganese steel increased with the increase of the acid value and sulfur content. Black-Right-Pointing-Pointer The critical values of the concentration of sulfur and acid for corrosion rate of the stainless steel were ascertained respectively. Black-Right-Pointing-Pointer The stainless steel is superior to the carbon-manganese steel in corrosion resistance because of the presence of stable Cr{sub 5}S{sub 8} phases. - Abstract: The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 Degree-Sign C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr{sub 5}S{sub 8} phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

Effects of compatibility of polymer binders with solvate ionic liquid electrolytes on discharge and charge reactions of lithium-sulfur batteries

Science.gov (United States)

Nakazawa, Toshitada; Ikoma, Ai; Kido, Ryosuke; Ueno, Kazuhide; Dokko, Kaoru; Watanabe, Masayoshi

2016-03-01

Electrochemical reactions in Li-S cells with a solvate ionic liquid (SIL) electrolyte composed of tetraglyme (G4) and Li[TFSA] (TFSA: bis(trifluoromethanesulfonyl)amide) are studied. The sulfur cathode (S cathode) comprises sulfur, carbon powder, and a polymer binder. Poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA-x) with different degrees of saponification (x%) are used as binders to prepare the composite cathodes. For the Li-S cell containing PEO binder, lithium polysulfides (Li2Sm, 2 ≤ m ≤ 8), reaction intermediates of the S cathode, dissolve into the electrolyte, and Li2Sm acts as a redox shuttle in the Li-S cell. In contrast, in the Li-S cell with PVA-x binder, the dissolution of Li2Sm is suppressed, leading to high columbic efficiencies during charge-discharge cycles. The compatibility of the PVA-x binder with the SIL electrolyte changes depending on the degree of saponification. Decreasing the degree of saponification leads to increased electrolyte uptake by the PVA-x binder, increasing the charge and discharge capacities of Li-S cell. The rate capability of Li-S cell is also enhanced by the partial swelling of the PVA-x binder. The enhanced performance of Li-S cell containing PVA-x is attributed to the lowering of resistance of Li+ ion transport in the composite cathode.

Electron-induced chemistry in microhydrated sulfuric acid clusters

Science.gov (United States)

Lengyel, Jozef; Pysanenko, Andriy; Fárník, Michal

2017-11-01

We investigate the mixed sulfuric acid-water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT) calculations. The microhydration of (H2SO4)m(H2O)n clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4)m(H2O)nHSO4- and (H2O)nH2SO4-. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4- ṡ ṡ ṡ H3O+) formation in the neutral H2SO4(H2O)n clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO4)2(H2O)n this process starts as early as n ≥ 2 water molecules. The (H2SO4)m(H2O)nHSO4- clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4- ṡ ṡ ṡ H3O+) ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2O)nH2SO4- cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid-water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid-water aerosols are discussed.

Design and cost of the sulfuric acid decomposition reactor for the sulfur based hydrogen processes - HTR2008-58009

International Nuclear Information System (INIS)

Hu, T. Y.; Connolly, S. M.; Lahoda, E. J.; Kriel, W.

2008-01-01

The key interface component between the reactor and chemical systems for the sulfuric acid based processes to make hydrogen is the sulfuric acid decomposition reactor. The materials issues for the decomposition reactor are severe since sulfuric acid must be heated, vaporized and decomposed. SiC has been identified and proven by others to be an acceptable material. However, SiC has a significant design issue when it must be interfaced with metals for connection to the remainder of the process. Westinghouse has developed a design utilizing SiC for the high temperature portions of the reactor that are in contact with the sulfuric acid and polymeric coated steel for low temperature portions. This design is expected to have a reasonable cost for an operating lifetime of 20 years. It can be readily maintained in the field, and is transportable by truck (maximum OD is 4.5 meters). This paper summarizes the detailed engineering design of the Westinghouse Decomposition Reactor and the decomposition reactor's capital cost. (authors)

Ice nucleation in sulfuric acid/organic aerosols: implications for cirrus cloud formation

Directory of Open Access Journals (Sweden)

M. R. Beaver

2006-01-01

Full Text Available Using an aerosol flow tube apparatus, we have studied the effects of aliphatic aldehydes (C3 to C10 and ketones (C3 and C9 on ice nucleation in sulfuric acid aerosols. Mixed aerosols were prepared by combining an organic vapor flow with a flow of sulfuric acid aerosols over a small mixing time (~60 s at room temperature. No acid-catalyzed reactions were observed under these conditions, and physical uptake was responsible for the organic content of the sulfuric acid aerosols. In these experiments, aerosol organic content, determined by a Mie scattering analysis, was found to vary with the partial pressure of organic, the flow tube temperature, and the identity of the organic compound. The physical properties of the organic compounds (primarily the solubility and melting point were found to play a dominant role in determining the inferred mode of nucleation (homogenous or heterogeneous and the specific freezing temperatures observed. Overall, very soluble, low-melting organics, such as acetone and propanal, caused a decrease in aerosol ice nucleation temperatures when compared with aqueous sulfuric acid aerosol. In contrast, sulfuric acid particles exposed to organic compounds of eight carbons and greater, of much lower solubility and higher melting temperatures, nucleate ice at temperatures above aqueous sulfuric acid aerosols. Organic compounds of intermediate carbon chain length, C4-C7, (of intermediate solubility and melting temperatures nucleated ice at the same temperature as aqueous sulfuric acid aerosols. Interpretations and implications of these results for cirrus cloud formation are discussed.

Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

Science.gov (United States)

Huang, B. S.; Yin, W. F.; Sang, D. H.; Jiang, Z. Y.

2012-10-01

The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 °C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr5S8 phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

Test fabrication of sulfuric acid decomposer applied for thermochemical hydrogen production IS process

International Nuclear Information System (INIS)

Noguchi, Hiroki; Terada, Atsuhiko; Kubo, Shinji; Onuki, Kaoru; Hino, Ryutaro; Ota, Hiroyuki

2007-07-01

Thermo-chemical Iodine-Sulfur (IS) process produces large amount of hydrogen effectively without carbon dioxide emission. Since the IS process uses strong acids such as sulfuric acid and hydriodic acid, it is necessary to develop large-scale chemical reactors featuring materials that exhibit excellent heat and corrosion resistance. A sulfuric acid decomposer is one of the key components of the IS process plant, in which sulfuric acid is evaporated and decomposed into water and sulfur trioxide under temperature range from 300degC to 500degC using the heat supplied by high temperature helium gas. The decomposer is exposed to severe corrosion condition of sulfuric acid boiling flow, where only the SiC ceramics shows good corrosion resistance. However, at the current status, it is very difficult to manufacture the large-scale SiC ceramics structure required in the commercial plant. Therefore, we devised a new concept of the decomposer, which featured a counter flow type heat exchanger consisting of cylindrical blocks made of SiC ceramics. Scale up can be realized by connecting the blocks in parallel and/or in series. This paper describes results of the design work and the test-fabrication study of the sulfuric acid decomposer, which was carried out in order to confirm its feasibility. (author)

Decomposition of silica-alumina ores of Afghanistan by sulfuric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2016-01-01

Present article is devoted to decomposition of silica-alumina ores of Afghanistan by sulfuric acid. Physicochemical properties of initial silica-alumina ores were studied by means of X-ray phase, differential thermal and silicate analysis. The influence of temperature, process duration and acid concentration on extraction rate of valuable components was considered. The optimal conditions of decomposition of silica-alumina ores of Afghanistan by sulfuric acid were proposed.

Sorbic acid interaction with sulfur dioxide in model food systems

Energy Technology Data Exchange (ETDEWEB)

Namor, O G

1987-01-01

The first chapter deals with the chemistry of sorbic acid and sulfur dioxide. The second chapter describes a study of the degradation products of sorbic acid, in aqueous systems, in the presence of sulfur dioxide and a possible mechanism for the occurrence of these products is proposed. Chapter three deals with the preparation and degradation of 6-(/sup 13/C)sorbic acid in order to find evidence for, or against, the mechanism proposed in chapter two. It also gives details of syntheses attempted in order to obtain 6- (/sup 13/C)sorbic acid. The interaction of sorbic acid and sulfur dioxide in real food systems is the subject of the fourth chapter. The food systems studied were mayonnaise, tomato puree, orange juice and cottage cheese. The effect of packaging on the rate of degradation of sorbic acid was also investigated. The final chapter deals with a microbiological study of two homologues of sorbic acid, 2,4-heptadienoic acid, 2,4-octadienoic acid. The fungicidal activity of these two compounds, towards selected fungi, was analyzed. 4-Oxobut-2-enoic acid, a degradation product of sorbic acid in aqueous systems, was also analyzed as a possible fungistat.

Heavy metal extraction from PCB wastewater treatment sludge by sulfuric acid

International Nuclear Information System (INIS)

Kuan, Yu-Chung; Lee, I-Hsien; Chern, Jia-Ming

2010-01-01

Heavy metals contaminated wastewater sludge is classified as hazardous solid waste and needs to be properly treated to prevent releasing heavy metals to the environment. In this study, the wastewater treatment sludge from a printed circuit board manufacturing plant was treated in a batch reactor by sulfuric acid to remove the contained heavy metals. The effects of sulfuric acid concentration and solid to liquid ratio on the heavy metal removal efficiencies were investigated. The experimental results showed that the total and individual heavy metal removal efficiencies increased with increasing sulfuric acid concentration, but decreased with increasing solid to liquid ratio. A mathematical model was developed to predict the residual sludge weights at varying sulfuric concentrations and solid to liquid ratios. The trivalent heavy metal ions, iron and chromium were more difficult to be removed than the divalent ions, copper, zinc, nickel, and cadmium. For 5 g/L solid to liquid ratio, more than 99.9% of heavy metals can be removed from the sludge by treating with 0.5 M sulfuric acid in 2 h.

Application of ionic liquids as an electrolyte additive on the electrochemical behavior of lead acid battery

Energy Technology Data Exchange (ETDEWEB)

Rezaei, Behzad; Mallakpour, Shadpour; Taki, Mahmood [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran)

2009-02-15

Ionic liquids (ILs) belong to new branch of salts with unique properties which their applications have been increasing in electrochemical systems especially lithium-ion batteries. In the present work, for the first time, the effects of four ionic liquids as an electrolyte additive in battery's electrolyte were studied on the hydrogen and oxygen evolution overpotential and anodic layer formation on lead-antimony-tin grid alloy of lead acid battery. Cyclic and linear sweep voltammetric methods were used for this study in aqueous sulfuric acid solution. The morphology of grid surface after cyclic redox reaction was studied using scanning electron microscopy. The results show that most of added ionic liquids increase hydrogen overpotential and whereas they have no significant effect on oxygen overpotential. Furthermore ionic liquids increase antimony dissolution that might be related to interaction between Sb{sup 3+} and ionic liquids. Crystalline structure of PbSO{sub 4} layer changed with presence of ionic liquids and larger PbSO{sub 4} crystals were formed with some of them. These additives decrease the porosity of PbSO{sub 4} perm selective membrane layer at the surface of electrode. Also cyclic voltammogram on carbon-PbO paste electrode shows that with the presence of ionic liquids, oxidation and reduction peak current intensively increased. (author)

Ion Irradiation of Sulfuric Acid: Implications for its Stability on Europa

Science.gov (United States)

Loeffler, M. J.; Hudson, R. L.; Moore, M. H.

2010-01-01

The Galileo near-infrared mapping spectrometer (NIMS) detected regions on Europa's surface containing distorted H2O bands. This distortion likely indicates that there are other molecules mixed with the water ice. Based on spectral comparison, some of the leading possibilities are sulfuric acid, salts. or possibly H3O(+). Previous laboratory studies have shown that sulfuric acid can be created by irradiation of H2OSO2 mixtures, and both molecules are present on Europa. In this project, we were interested in investigating the radiation stability of sulfuric acid (H2SO4) and determining its lifetime on the surface of Europa.

In-test and post-test analyses of sodium-sulfur cells

Energy Technology Data Exchange (ETDEWEB)

Wada, Motoi; Kawamoto, Hiroyuki; Hatoh, Hisamitsu

1986-01-15

Cell life of sodium-sulfur cells is often determined by the degradation of the solid electrolyte. Solid electrolyte degradation will cause an increase of electrolyte resistivity, decrease of faradic efficiency, or even an electrolyte rupture which leads to a cell temperature rise due to direct reaction of reactants. Electrolyte degradation in actual sodium-sulfur cells is believed to be caused by the passage of sodium ion current across the solid electrolyte. The degree of degradation has been reported to be a function of amount of charge passed through the electrolyte, and the breakdown of the solid electrolyte was observed to occur above some threshold. For this reason, the concentration of sodium ion current density is to be avoided to prevent solid electrolyte from premature degradation and rupture, and the electrode structure for a sodium-sulfur cell should be determined with enough care to homogenize the current density distribution on the electrolyte. The longitudinal current density distribution of a sodium-sulfur cell was measured by attaching probing terminals on the electrode container. It was found that the current density distribution of a vertically supported cell was inhomogeneous due to the effect of gravity. This setup can be used as a way to locate the place where the first electrolyte cracking occurs. It was also found that the electrolyte cracking accompanies a fluctuation of cycling cell voltage that starts to appear several cycles before the noticeable break down of the electrolyte.

Process for electrolytic deposition of metals on zirconium materials

International Nuclear Information System (INIS)

Donaghy, R.E.

1981-01-01

An article made of a zirconium alloy can be electrolytically plated with a layer of a metal such as copper, nickel or chromium when the article is free of any loosely adhering film formed during an activation step. The article is activated in an aged aqueous solution of ammonium bifluoride and sulfuric acid. Next the loosely adhering film formed in the first step is removed by chemical treatment, ultrasonic cleaning, or by swabbing the surface with cotton or an organic material. Finally the article is contacted with an electrolytic plating solution in the presence of an electrode receiving current

Operating experience with unit for sulfuric acid alkylation of isobutane by butylenes

Energy Technology Data Exchange (ETDEWEB)

Tagavov, I.T.; Sumanov, V.T.; Khadzhiev, S.N.

1988-09-01

The operation of units for the sulfuric acid alkylation of isobutanes by butylenes have been performed. The reaction was carried out in a KSG-3 horizontal sulfuric acid contractor. A butane-butylene fraction from catalytic cracking and an isobutane fraction from the central gas fractionating unit were used as a feedstock. The studies have shown that the unit will give a high-quality product under various conditions of operation. The specific consumption of sulfuric acid in processing different types of feed remains within acceptable limits.

Pore development in anodic alumina in sulphuric acid and borax electrolytes

International Nuclear Information System (INIS)

Garcia-Vergara, S.J.; Skeldon, P.; Thompson, G.E.; Habakaki, H.

2007-01-01

The formation of porous anodic films on an Al-3.5 at.%W alloy is compared in sulphuric acid and borax electrolytes in order to investigate pore development processes. The findings disclose that for anodizing in sulphuric acid, the pores develop mainly due to the influences of field-induced plasticity of the film and growth stresses; in borax, field-assisted dissolution dominates. The films formed in sulphuric acid are consequently much thicker than the layer of oxidized alloy and tungsten species are retained in the film. In contrast, with borax, the films and oxidized alloy layers are of similar thickness and tungsten species are lost to the electrolyte. Efficiencies of film growth are also significantly different, about 65% in sulphuric acid and about 52% in borax. The retention of tungsten species during anodizing in sulphuric acid is due to the localization of tungsten in the inner regions of the barrier layer and cell walls, with a layer of anodic alumina separating the tungsten-containing regions from the electrolyte. For borax, the tungsten is distributed more uniformly through the film material, enabling loss of tungsten species to the electrolyte from the pore base

Characteristics of a continuous denitration by formic acid - electrolytic trimming of residual acid with accompanying the precipitation of metal ions

International Nuclear Information System (INIS)

Kim, G. W.; Kim, S. H.; Lim, J. G.; Lee, I. H.

2003-01-01

This work has studied the characteristics of destruction of nitric acid and precipitation of several metal ions in a continuous denitration process combining a denitration by formic acid and a residual acid-electrolytic trimming system. The metal ions of Zr, Mo, Fe, and Nd did not affect the electrodes at the step of electrolytic trimming of the residual acid after denitration by formic acid. The Mo ion in electrolytic solution enhanced the generation of nitrite ion during the electrolytic reaction. The mole ratio of formic acid to nitric acid fed into the continuous denitration reactor using formic acid affected much the final acidity, the precipitation yields of metal ions, the precipitate morphology. At the ratio of 1.65, the process had the lowest final acidity of less than 0.1 M, and the precipitation yields of Zr and Mo reached 95% and 83%, respectively as the highest values

Electrochemical Study of Hydrocarbon-Derived Electrolytes for Supercapacitors

Science.gov (United States)

Noorden, Zulkarnain A.; Matsumoto, Satoshi

2013-10-01

In this paper, we evaluate the essential electrochemical properties - capacitive and resistive behaviors - of hydrocarbon-derived electrolytes for supercapacitor application using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrolytes were systematically prepared from three hydrocarbon-derived compounds, which have different molecular structures and functional groups, by treatment with high-concentration sulfuric acid (H2SO4) at room temperature. Two-electrode cells were assembled by sandwiching an electrolyte-containing glass wool separator with two active electrodes of activated carbon sheets. The dc electrical properties of the tested cells in terms of their capacitive behavior were investigated by CV, and in order to observe the frequency characteristics of the constructed cells, EIS was carried out. Compared with the tested cell with only high-concentration H2SO4 as the electrolyte, the cell with the derived electrolytes exhibit a capacitance as high as 135 F/g with an improved overall internal resistance of 2.5 Ω. Through the use of a simple preparation method and low-cost precursors, hydrocarbon-derived electrolytes could potentially find large-scale and higher-rating supercapacitor applications.

3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

Solid electrolyte fuel cells

Science.gov (United States)

Isaacs, H. S.

Progress in the development of functioning solid electrolyte fuel cells is summarized. The solid electrolyte cells perform at 1000 C, a temperature elevated enough to indicate high efficiencies are available, especially if the cell is combined with a steam generator/turbine system. The system is noted to be sulfur tolerant, so coal containing significant amounts of sulfur is expected to yield satisfactory performances with low parasitic losses for gasification and purification. Solid oxide systems are electrically reversible, and are usable in both fuel cell and electrolysis modes. Employing zirconium and yttrium in the electrolyte provides component stability with time, a feature not present with other fuel cells. The chemical reactions producing the cell current are reviewed, along with materials choices for the cathodes, anodes, and interconnections.

Substrate selection for fundamental studies of electrocatalysts and photoelectrodes: inert potential windows in acidic, neutral, and basic electrolyte.

Directory of Open Access Journals (Sweden)

Jesse D Benck

Full Text Available The selection of an appropriate substrate is an important initial step for many studies of electrochemically active materials. In order to help researchers with the substrate selection process, we employ a consistent experimental methodology to evaluate the electrochemical reactivity and stability of seven potential substrate materials for electrocatalyst and photoelectrode evaluation. Using cyclic voltammetry with a progressively increased scan range, we characterize three transparent conducting oxides (indium tin oxide, fluorine-doped tin oxide, and aluminum-doped zinc oxide and four opaque conductors (gold, stainless steel 304, glassy carbon, and highly oriented pyrolytic graphite in three different electrolytes (sulfuric acid, sodium acetate, and sodium hydroxide. We determine the inert potential window for each substrate/electrolyte combination and make recommendations about which materials may be most suitable for application under different experimental conditions. Furthermore, the testing methodology provides a framework for other researchers to evaluate and report the baseline activity of other substrates of interest to the broader community.

Wolframite Conversion in Treating a Mixed Wolframite-Scheelite Concentrate by Sulfuric Acid

Science.gov (United States)

Shen, Leiting; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui; Taskinen, Pekka

2018-02-01

Complete wolframite conversion in sulfuric acid is significant for expanding the applicability of the sulfuric acid method for producing ammonium paratungstate. In this paper, the conversion of wolframite in treating a mixed wolframite-scheelite concentrate by sulfuric acid was studied systematically. The results show that the conversion of wolframite in sulfuric acid is more difficult than that of scheelite, requiring rigorous reaction conditions. A solid H2WO4 layer forms on the surfaces of the wolframite particles and becomes denser with increasing H2SO4 concentration, thus hindering the conversion. Furthermore, the difficulty in wolframite conversion can be mainly attributed to the accumulation of Fe2+ (and/or Mn2+) in the H2SO4 solution, which can be solved by reducing Fe2+ (and/or Mn2+) concentration through oxidization and/or a two-stage process. Additionally, the solid converted product of the mixed wolframite-scheelite concentrate has an excellent leachability of tungsten in an aqueous ammonium carbonate solution at ambient temperature, with approximately 99% WO3 recovery. This work presents a route for manufacturing ammonium paratungstate by treating the mixed concentrate in sulfuric acid followed by leaching in ammonium carbonate solution.

Intestinal metabolism of sulfur amino acids

Science.gov (United States)

The gastrointestinal tract (GIT) is a metabolically significant site of sulfur amino acid (SAA) metabolism in the body and metabolizes approx. 20% of the dietary methionine intake that is mainly transmethylated to homocysteine and transsulfurated to cysteine. The GIT accounts for approx. 25% of the ...

Stabilization of sulfuric acid dimers by ammonia, methylamine, dimethylamine, and trimethylamine

Science.gov (United States)

Jen, Coty N.; McMurry, Peter H.; Hanson, David R.

2014-06-01

This study experimentally explores how ammonia (NH3), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) affect the chemical formation mechanisms of electrically neutral clusters that contain two sulfuric acid molecules (dimers). Dimers may also contain undetectable compounds, such as water or bases, that evaporate upon ionization and sampling. Measurements were conducted using a glass flow reactor which contained a steady flow of humidified nitrogen with sulfuric acid concentrations of 107 to 109 cm-3. A known molar flow rate of a basic gas was injected into the flow reactor. The University of Minnesota Cluster Chemical Ionization Mass Spectrometer was used to measure the resulting sulfuric acid vapor and cluster concentrations. It was found that, for a given concentration of sulfuric acid vapor, the dimer concentration increases with increasing concentration of the basic gas, eventually reaching a plateau. The base concentrations at which the dimer concentrations saturate suggest NH3 heuristic models for cluster formation by acid-base reactions are developed to interpret the data. The models provide ranges of evaporation rate constants that are consistent with observations and leads to an analytic expression for nucleation rates that is consistent with atmospheric observations.

PUMP DESIGN AND COMPUTATIONAL FLUID DYNAMIC ANALYSIS FOR HIGH TEMPERATURE SULFURIC ACID TRANSFER SYSTEM

Directory of Open Access Journals (Sweden)

JUNG-SIK CHOI

2014-06-01

Full Text Available In this study, we proposed a newly designed sulfuric acid transfer system for the sulfur-iodine (SI thermochemical cycle. The proposed sulfuric acid transfer system was evaluated using a computational fluid dynamics (CFD analysis for investigating thermodynamic/hydrodynamic characteristics and material properties. This analysis was conducted to obtain reliable continuous operation parameters; in particular, a thermal analysis was performed on the bellows box and bellows at amplitudes and various frequencies (0.1, 0.5, and 1.0 Hz. However, the high temperatures and strongly corrosive operating conditions of the current sulfuric acid system present challenges with respect to the structural materials of the transfer system. To resolve this issue, we designed a novel transfer system using polytetrafluoroethylene (PTFE, Teflon® as a bellows material for the transfer of sulfuric acid. We also carried out a CFD analysis of the design. The CFD results indicated that the maximum applicable temperature of PTFE is about 533 K (260 °C, even though its melting point is around 600 K. This result implies that the PTFE is a potential material for the sulfuric acid transfer system. The CFD simulations also confirmed that the sulfuric acid transfer system was designed properly for this particular investigation.

Accidents with sulfuric acid

OpenAIRE

Rajković Miloš B.

2006-01-01

Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

Science.gov (United States)

Moore, Robert [Edgewood, NM; Pickard, Paul S [Albuquerque, NM; Parma, Jr., Edward J.; Vernon, Milton E [Albuquerque, NM; Gelbard, Fred [Albuquerque, NM; Lenard, Roger X [Edgewood, NM

2010-01-12

A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

Corn stover lignin is modified differently by acetic acid compared to sulfuric acid

NARCIS (Netherlands)

Mouthier, Thibaut; Appeldoorn, Maaike M.; Pel, Herman; Schols, Henk A.; Gruppen, Harry; Kabel, Mirjam A.

2018-01-01

In this study, two acid catalysts, acetic acid (HAc) and sulfuric acid (H2SO4), were compared in thermal pretreatments of corn stover, in particular to assess the less understood fate of lignin. HAc-insoluble lignin, analyzed by pyrolysis GC–MS, showed decreasing levels (%) of Cα-oxidized (from 3.7

What Is the Boiling Point and Heat of Vaporization of Sulfuric Acid?

Science.gov (United States)

Myers, R. Thomas

1983-01-01

Discusses the values presented in various handbooks for the boiling point and heat of vaporization of sulfuric acid, noting discrepencies. Analyzes various approaches to data presentation, discussing the data on sulfuric acid in light of the Trouton constant. Points out the need for a more critical use of tables. (JM)

Vanadium Extraction from Shale via Sulfuric Acid Baking and Leaching

Science.gov (United States)

Shi, Qihua; Zhang, Yimin; Liu, Tao; Huang, Jing

2018-01-01

Fluorides are widely used to improve vanadium extraction from shale in China. Sulfuric acid baking-leaching (SABL) was investigated as a means of recovering vanadium which does not require the use of fluorides and avoids the productions of harmful fluoride-containing wastewater. Various effective factors were systematically studied and the experimental results showed that 90.1% vanadium could be leached from the shale. On the basis of phase transformations and structural changes after baking the shale, a mechanism of vanadium extraction from shale via SABL was proposed. The mechanism can be described as: (1) sulfuric acid diffusion into particles; (2) the formation of concentrated sulfuric acid media in the particles after water evaporation; (3) hydroxyl groups in the muscovite were removed and transient state [SO4 2-] was generated; and (4) the metals in the muscovite were sulfated by active [SO4 2-] and the vanadium was released. Thermodynamics modeling confirmed this mechanism.

Measuring and modeling aqueous electrolyte/amino-acid solutions with ePC-SAFT

International Nuclear Information System (INIS)

Held, Christoph; Reschke, Thomas; Müller, Rainer; Kunz, Werner; Sadowski, Gabriele

2014-01-01

Highlights: • Amino-acid solubilities and osmotic coefficients in ternary solutions containing one amino acids and one salt measured. • Weak salt influence on amino-acid solubilities except for salts containing Mg [2+] or NO 3 [−] (salting-in behavior). • Osmotic coefficients dominated by the solute with the highest molality. • Amino-acid solubilities and osmotic coefficients predicted reasonably with ePC-SAFT with deviations of 3.7% and 9.3%. • Predictions based on pure-component parameters for ions and amino acids using no ion/amino-acid fitting parameters. -- Abstract: In this work thermodynamic properties of electrolyte/amino acid/water solutions were measured and modeled. Osmotic coefficients at 298.15 K were measured by means of vapor-pressure osmometry. Amino-acid solubility at 298.15 K was determined gravimetrically. Considered aqueous systems contained one of the four amino acids: glycine, L-/DL-alanine, L-/DL-valine, and L-proline up to the respective amino-acid solubility limit and one of 13 salts composed of the ions Li + , Na + , K + , NH 4 + , Cl − , Br − , I − , NO 3 − , and SO 4 2− at salt molalities of 0.5, 1.0, and 3.0 mol · kg −1 , respectively. The data show that the salt influence is more pronounced on osmotic coefficients than on amino-acid solubility. The electrolyte Perturbed-Chain Statistical Association Theory (ePC-SAFT) was applied to model thermodynamic properties in aqueous electrolyte/amino-acid solutions. In previous works, this model had been applied to binary salt/water and binary amino acid/water systems. Without fitting any additional parameters, osmotic coefficients and amino-acid solubility in the ternary electrolyte/amino acid/water systems could be predicted with overall deviations of 3.7% and 9.3%, respectively, compared to the experimental data

Oscillatory bromate-oxalic acid-Ce-acetone-sulfuric acid reaction, in CSTR

International Nuclear Information System (INIS)

Pereira, Janaina A.M.; Faria, Roberto B.

2004-01-01

Periodic oscillations were observed for the first time, in a CSTR, in the system bromate-oxalic acid-Ce(IV)-acetone-sulfuric acid, in a CSTR. A reaction between Ce(IV) and acetone, until now not described in the literature and occurring before the addition of the reagents to the reactor, was identified as a decisive factor for the appearing of the regular oscillations. (author)

Characteristics of Sulfuric Acid Condensation on Cylinder Liners of Large Two-Stroke Marine Engines

DEFF Research Database (Denmark)

Cordtz, Rasmus Lage; Mayer, Stefan; Schramm, Jesper

. Formation of corrosive sulfuric acid in the cylinder gas is modeled with a cali-brated engine model that incorporates a detailed sulfur reaction mechanism. Condensation of sulfuric acid follows the analogy between heat and mass transfer. Average bulk gas acid dew points are calculated by applying two......-phase thermochemistry of the binary H2O-H2SO4 system. Max dew points of typically more than 200 °C are modeled close to max pressure and variations in terms of operating conditions are not large. However small increments of the dew point provided by e.g. the residual gas fraction, operating pressure, sulfur content...

Sulfuric acid nucleation: power dependencies, variation with relative humidity, and effect of bases

Directory of Open Access Journals (Sweden)

J. H. Zollner

2012-05-01

Full Text Available Nucleation of particles composed of sulfuric acid, water, and nitrogen base molecules was studied using a continuous flow reactor. The particles formed from these vapors were detected with an ultrafine condensation particle counter, while vapors of sulfuric acid and nitrogen bases were detected by chemical ionization mass spectrometry. Variation of particle numbers with sulfuric acid concentration yielded a power dependency on sulfuric acid of 5 ± 1 for relative humidities of 14–68% at 296 K; similar experiments with varying water content yielded power dependencies on H₂O of ~7. The critical cluster contains about 5 H₂SO₄ molecules and a new treatment of the power dependency for H₂O suggests about 12 H₂O molecules for these conditions. Addition of 2-to-45 pptv of ammonia or methyl amine resulted in up to millions of times more particles than in the absence of these compounds. Particle detection capabilities, sulfuric acid and nitrogen base detection, wall losses, and the extent of particle growth are discussed. Results are compared to previous laboratory nucleation studies and they are also discussed in terms of atmospheric nucleation scenarios.

A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

Directory of Open Access Journals (Sweden)

Martin Winter

2013-08-01

Full Text Available We report on studies of an inorganic electrolyte: LiAlCl4 in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl4 × 1.6SO2, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

Studies on distribution and residue of sulfur in simulated acid rain in vegetable and soil by using 35S

International Nuclear Information System (INIS)

Wan Zhaoliang; Liu Dayong

1995-01-01

Distribution and residue of sulfur in simulated acid rain in two kinds of vegetables (lettuce and Chinese cabbage) and three types of soils (acid yellow earth, acid and neutral purple soils) were studied by using 35 S tracer method. The results showed that the higher concentration of acid rain was sprayed, the more residue of sulfur in vegetable there would be. The residue of sulfur in vegetable varied with the different physical and chemical properties of soils, the order of sulfur residue in vegetable was: acid purple soil>acid yellow earth>neutral purple soil. In the same soil, the residue of sulfur in lettuce was higher than that in Chinese cabbage, for the same vegetable, the residue of sulfur in leaves were higher than that in stems. The order of sulfur residue in different soils was acid purple soil>acid yellow earth>neutral purple soil. The higher concentration of acid rain was sprayed, the more residue of sulfur in soil surface there would be. The sulfur residue varied with the depth of soil and the pH value of acid rain. With the increase of soil depth, a slight increase of sulfur residue with rain of ph 6 and a slight decrease with rain of pH 4.0 and 2.5 were found

Experimental Investigation of Sulfuric Acid Condensation and Corrosion Rate in Motored Bukh DV24 Diesel Engine

DEFF Research Database (Denmark)

Kjemtrup, Lars; Cordtz, Rasmus Faurskov; Meyer, Martin

2017-01-01

The work conducted in this paper presents a novel experimental setup to study sulfuric acid cold corrosion of cylinder liners in large two-stroke marine diesel engines. The process is simulated in a motored light duty BUKH DV24 diesel engine where the charge air contain known amounts of H2SO4 and H......2O vapor. Liner corrosion is measured as iron accumulation in the lubeoil. Similarly sulfuric acid condensation is assessed by measuring the accumulation of sulfur in the lube oil. To clarify the corrosive effect of sulfuric acid the lube oil utilized for experiments is a sulfur free neutral oil...... without alkaline additives (Chevron Neutral Oil 600R). Iron and sulfur accumulation in the lube oil is analyzed withan Energy Dispersive X-Ray Fluorescence (ED-XRF) apparatus. Three test cases with different H2SO4 concentrations are run. Results reveal good agreement between sulfuric acid injection flow...

Applicability test of glass lining material for high-temperature acidic solutions of sulfuric acid in thermochemical water-splitting IS process

International Nuclear Information System (INIS)

Iwatsuki, Jin; Tanaka, Nobuyuki; Terada, Atsuhiko; Onuki, Kaoru; Watanabe, Yutaka

2010-01-01

A key issue for realizing the thermochemical IS process for hydrogen production is the selection of materials for working with high-temperature acidic solutions of sulfuric acid and hydriodic acid. Glass lining material is a promising candidate, which is composed of steel having good strength and glass having good corrosion resistance. Since the applicability of glass lining material depends strongly on the service condition, corrosion tests using glass used in glass lining material and heat cycle tests using glass lining piping were carried out to examine the possibility of using the glass lining material with high-temperature acidic solutions of sulfuric acid. It was confirmed that the glass lining materials exhibited sufficient corrosion resistance and heat resistance in high-temperature sulfuric acid of the IS process. (author)

Control Room Habitability for Accidental Sulfuric Acid Release

International Nuclear Information System (INIS)

Cho, Sungmin; Lee, Heedo; Song, Dongsoo

2006-01-01

The 10 CFR 50 Appendix A Criterion 19, 'Control Room', requires that a control room be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions. For compliance with the requirement, the control room of a nuclear power plant should be appropriately protected from hazardous chemicals that may be discharged as a result of equipment failures, operator errors, or events and conditions outside the control of the nuclear power plant. We have excluded sulfuric acid from a target of estimation for control room habitability merely because its boiling point is too high; qualitative analysis in this paper shows that we can exclude sulfuric acid from the target of habitability estimation

Neurologic complications of electrolyte disturbances and acid-base balance.

Science.gov (United States)

Espay, Alberto J

2014-01-01

Electrolyte and acid-base disturbances are common occurrences in daily clinical practice. Although these abnormalities can be readily ascertained from routine laboratory findings, only specific clinical correlates may attest as to their significance. Among a wide phenotypic spectrum, acute electrolyte and acid-base disturbances may affect the peripheral nervous system as arreflexic weakness (hypermagnesemia, hyperkalemia, and hypophosphatemia), the central nervous system as epileptic encephalopathies (hypomagnesemia, dysnatremias, and hypocalcemia), or both as a mixture of encephalopathy and weakness or paresthesias (hypocalcemia, alkalosis). Disabling complications may develop not only when these derangements are overlooked and left untreated (e.g., visual loss from intracranial hypertension in respiratory or metabolic acidosis; quadriplegia with respiratory insufficiency in hypermagnesemia) but also when they are inappropriately managed (e.g., central pontine myelinolisis when rapidly correcting hyponatremia; cardiac arrhythmias when aggressively correcting hypo- or hyperkalemia). Therefore prompt identification of the specific neurometabolic syndromes is critical to correct the causative electrolyte or acid-base disturbances and prevent permanent central or peripheral nervous system injury. This chapter reviews the pathophysiology, clinical investigations, clinical phenotypes, and current management strategies in disorders resulting from alterations in the plasma concentration of sodium, potassium, calcium, magnesium, and phosphorus as well as from acidemia and alkalemia. © 2014 Elsevier B.V. All rights reserved.

Interaction between titanium and sulfuric acid in the electrodeposition of chalcogenide semiconductors

International Nuclear Information System (INIS)

Ortega, J.

1992-01-01

Some chalcogenide electrodeposition problems in the cathodic potential range from -0.30 V to-0.65 V vs SCE may be related to the Titanium corrosion-passivation process in aqueous solutions of sulfuric acid. This feature was discovered accidentally when it was attempted to electrodeposit Cd-Hg-Te compounds from a ternary plating bath; an anodic current of about 10 m/cm 2 was produced in the Titanium cathode at -0.50 V vs SCE, while at -0.40 and -0.60 V vs SCE the current was cathodic. In order to explain this feature, a first study has been carried out to determine the influence of the temperature and sulfuric acid concentration on the passivation current density, passivation potential and Flade potential for passivation. From Arrhenius plots of the passivation currents an apparent activation energy of 63.8 kJ/mole for Titanium passivation in sulfuric acid at -0.50 V vs SCE was obtained. The electrochemical stability of passivated Titanium was explained by assuming that the oxide film formed exhibits n-type semiconducting character, since passivation data was in good agreement with interfacial energetics for n-TiO 2 in aqueous solutions of sulfuric acid.(Author)

Thermal dynamic analysis of sulfur removal from coal by electrolysis

Energy Technology Data Exchange (ETDEWEB)

Li, D.; Gao, J.; Meng, F. [Qinghua University, Beijing (China). Dept. of Thermal Engineering

2002-06-01

The electrolytic reactions about sulfur removal from coal were studied by using chemical thermal dynamic analysis. According to the thermodynamical data, the Gibbs free energy value of the electrolytic reactions of pyritic and organic sulfur removal from coal is higher than zero. So, these electrolytic reactions are not spontaneous chemical reactions. In order to carry out desulfurisation by electrolysis, a certain voltage is necessary and important. Because theoretic decomposition voltage of pyrite and some parts of organic sulfur model compound is not very high, electrolysis reactions are easily to be carried out by using electrolysis technology. Mn ion and Fe ion are added into electrolysis solutions to accelerate the desulfurisation reaction. The electrolytic decomposition of coal is discussed. Because the theoretical decomposition voltage of some organic model compound is not high, the coal decomposition might happen. 17 refs., 4 tabs.

Study on the utilization of a sodium-sulfuric acid solution for the uranium minerals' leaching

International Nuclear Information System (INIS)

Echenique, Patricia; Fruchtenicht, Fernando; Gil, Daniel; Vigo, Daniel; Bouza, Angel; Vert, Gabriela; Becquart, Elena

1988-01-01

Argentine uranium minerals have been leached at bench scale with a different agent trying to reduce sulfuric acid consumption. The leaching agent was a sodium sulfate-sulfuric acid solution and the ore was from Sierra Pintada (San Rafael - Mendoza). The work was performed in stirred vessel at atmospheric pressure. The influence of different variables, pH, temperature, oxidant agent, sodium sulfate concentration and time, in the sulfuric acid consumption and the uranium yield was studied. (Author) [es

Ionic Liquid Catalyzed Electrolyte for Electrochemical Polyaniline Supercapacitors

Science.gov (United States)

Inamdar, A. I.; Im, Hyunsik; Jung, Woong; Kim, Hyungsang; Kim, Byungchul; Yu, Kook-Hyun; Kim, Jin-Sang; Hwang, Sung-Min

2013-05-01

The effect of different wt.% of ionic liquid "1,6-bis (trimethylammonium-1-yl) hexane tetrafluoroborate" in 0.5 M LiClO4+PC electrolyte on the supercapacitor properties of polyaniline (PANI) thin film are investigated. The PANI film is synthesized using electropolymerization of aniline in the presence of sulfuric acid. The electrochemical properties of the PANI thin film are studied by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) measurements. The optimum amount of the ionic liquid is found to be 2 wt.% which provides better ionic conductivity of the electrolyte. The highest specific capacitance of 259 F/g is obtained using the 2 wt.% electrolyte. This capacitance remains at up to 208 F/g (80% capacity retention) after 1000 charge-discharge cycles at a current density of 0.5 mA/g. The PANI film in the 2 wt.% ionic liquid catalyzed 0.5 M LiClO4+PC electrolyte shows small electrochemical resistance, better rate performance and higher cyclability. The increased ionic conductivity of the 2 wt.% ionic liquid catalyzed electrolyte causes a reduction in resistance at the electrode/electrolyte interface, which can be useful in electrochemically-preferred power devices for better applicability.

FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL; SEMIANNUAL

International Nuclear Information System (INIS)

Gary M. Blythe

2002-01-01

This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period October 1, 2001 through March 31, 2002. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO(sub X) selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the fifth reporting period for the subject Cooperative Agreement. During the previous (fourth) period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant) and a byproduct magnesium hydroxide slurry (at both Gavin and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO(sub 3) formed across the SCR system installed on the unit for NO(sub X) control than at removing SO(sub 3) formed in the furnace. The SO(sub 3) removal results were presented in the

Thermal Regeneration of Sulfuric Acid Hydrates after Irradiation

Science.gov (United States)

Loeffler, Mark J.; Hudson, Reggie L.

2012-01-01

In an attempt to more completely understand the surface chemistry of the jovian icy satellites, we have investigated the effect of heating on two irradiated crystalline sulfuric acid hydrates, H2SO4 4H2O and H2SO4 H2O. At temperatures relevant to Europa and the warmer jovian satellites, post-irradiation heating recrystallized the amorphized samples and increased the intensities of the remaining hydrate's infrared absorptions. This thermal regeneration of the original hydrates was nearly 100% efficient, indicating that over geological times, thermally-induced phase transitions enhanced by temperature fluctuations will reform a large fraction of crystalline hydrated sulfuric acid that is destroyed by radiation processing. The work described is the first demonstration of the competition between radiation-induced amorphization and thermally-induced recrystallization in icy ionic solids relevant to the outer Solar System.

A sulfuric-lactic acid process for efficient purification of fungal chitosan with intact molecular weight.

Science.gov (United States)

Naghdi, Mitra; Zamani, Akram; Karimi, Keikhosro

2014-02-01

The most recent method of fungal chitosan purification, i.e., two steps of dilute sulfuric acid treatment, pretreatment of cell wall at room temperature for phosphate removal and extraction of chitosan from the phosphate free cell wall at high temperature, significantly reduces the chitosan molecular weight. This study was aimed at improvement of this method. In the pretreatment step, to choose the best conditions, cell wall of Rhizopus oryzae, containing 9% phosphate, 10% glucosamine, and 21% N-acetyl glucosamine, was treated with sulfuric, lactic, acetic, nitric, or hydrochloric acid, at room temperature. Sulfuric acid showed the best performance in phosphate removal (90%) and cell wall recovery (89%). To avoid depolymerisation of chitosan, hot sulfuric acid extraction was replaced with lactic acid treatment at room temperature, and a pure fungal chitosan was obtained (0.12 g/g cell wall). Similar pretreatment and extraction processes were conducted on pure shrimp chitosan and resulted in a chitosan recovery of higher than 87% while the reduction of chitosan viscosity was less than 15%. Therefore, the sulfuric-lactic acid method purified the fungal chitosan without significant molecular weight manipulation. Copyright © 2013 Elsevier B.V. All rights reserved.

Contribution of sulfuric acid and oxidized organic compounds to particle formation and growth

Directory of Open Access Journals (Sweden)

F. Riccobono

2012-10-01

Full Text Available Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to the formation and early growth of nucleated particles. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and α-pinene showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two chemical ionization mass spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene.

New analysis methods were applied to the data collected with a condensation particle counter battery and a scanning mobility particle sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (Γ, defined as the ratio between the measured growth rate in the presence of α-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed Γ values indicate that the growth is already dominated by organic compounds at particle diameters of 2 nm. Both the absolute growth rates and Γ showed a strong dependence on particle size, supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particle growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. Finally, the size resolved growth analysis indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.

Electron-induced chemistry in microhydrated sulfuric acid clusters

Directory of Open Access Journals (Sweden)

J. Lengyel

2017-11-01

Full Text Available We investigate the mixed sulfuric acid–water clusters in a molecular beam experiment with electron attachment and negative ion mass spectrometry and complement the experiment by density functional theory (DFT calculations. The microhydration of (H2SO4m(H2On clusters is controlled by the expansion conditions, and the electron attachment yields the main cluster ion series (H2SO4m(H2OnHSO4− and (H2OnH2SO4−. The mass spectra provide an experimental evidence for the onset of the ionic dissociation of sulfuric acid and ion-pair (HSO4−  ⋅  ⋅  ⋅  H3O+ formation in the neutral H2SO4(H2On clusters with n ≥ 5 water molecules, in excellent agreement with the theoretical predictions. In the clusters with two sulfuric acid molecules (H2SO42(H2On this process starts as early as n ≥ 2 water molecules. The (H2SO4m(H2OnHSO4− clusters are formed after the dissociative electron attachment to the clusters containing the (HSO4−  ⋅  ⋅  ⋅  H3O+ ion-pair structure, which leads to the electron recombination with the H3O+ moiety generating H2O molecule and the H-atom dissociation from the cluster. The (H2OnH2SO4− cluster ions point to an efficient caging of the H atom by the surrounding water molecules. The electron-energy dependencies exhibit an efficient electron attachment at low electron energies below 3 eV, and no resonances above this energy, for all the measured mass peaks. This shows that in the atmospheric chemistry only the low-energy electrons can be efficiently captured by the sulfuric acid–water clusters and converted into the negative ions. Possible atmospheric consequences of the acidic dissociation in the clusters and the electron attachment to the sulfuric acid–water aerosols are discussed.

15N NMR spectroscopic investigation of nitrous and nitric acids in sulfuric acid solutions of varying acidities

International Nuclear Information System (INIS)

Prakash, G.K.S.; Heiliger, L.; Olah, G.A.

1990-01-01

Both nitrous and nitric acids were studied in sulfuric acid solutions of varying acid strengths by 15 N NMR spectroscopy. The study gives new insights into the nature of intermediates present at different acid strengths. Furthermore, we have also discovered a novel redox reaction between NO 2 + and NO + ions involving the intermediacy of their respective acids. A mechanism is proposed to explain the observed results. 13 refs., 2 figs., 1 tab

Thermochemistry of interaction between zirconium disulfate and sulfuric acid

International Nuclear Information System (INIS)

Dmitrieva, S.V.; Chekmarev, A.M.; Vorob'ev, A.F.

1988-01-01

Thermochemistry of Zr(SO 4 ) 2 x4H 2 O (1) interaction with water and sulfuric acid solutions of different concentrations is studied. It is established that the dependence of 1 solution enthalpy on acid concentration 1-bars of a complex polyextreme nature. It is noted that the increase in exothermic nature of dissolving during the increase of H 2 SO 4 concentration from 0.05 to 0.50 mol/l is explained by zirconium hydroxosulfate and fulfate complexes substitution for hydroxocomplexes. The endothermal nature of 1 interaction with concentrated (>3 mol/l) H 2 SO 4 solutions is conditioned by the formation of acidocomplexes. It is assumed that the abrupt growth of the exothermal nature of 1 interaction with sulfuric acid solutions with the concentration less than 0.05 mol/l with water is connected with colloid formation. 12 refs.; 2 figs

A dynamic study on the sulfuric acid distillation column for VHTR-assisted hydrogen production systems

International Nuclear Information System (INIS)

Youngjoon, Shin; Heesung, Shin; Jiwoon, Jang; Kiyoung, Lee; Jonghwa, Chang

2007-01-01

The sulfur-iodine (SI) cycle and the Westinghouse sulfur hybrid cycle coupled to a very high temperature gas-cooled reactor (VHTR) are well known as a feasible technology to produce hydrogen. The concentration of the sulfuric acid solution and its decomposition are essential parts in both cycles. In this paper, the thermophysical properties which are the boiling point, latent heat, and the partial pressures of water, sulfuric acid, and sulfur trioxide have been correlated as a function of the sulfuric acid concentration for the H 2 SO 4 and H 2 O binary chemical system, based on the data in Perry's chemical engineers' hand-book and other experimental data. By using these thermophysical correlations, a dynamic analysis of a sulfuric acid distillation column has been performed to establish the column design requirements and its optimum operation condition. From the results of the dynamic analysis, an optimized column system is anticipated for a distillation column equipped with 2 ideal plates and a second plate feeding system from the bottom plate. The effects of the hold-up of the re-boiler and the reflux ratio from the top product stream on the elapsing time when the system progresses toward a steady state have been analyzed. (authors)

Non-spectral interferences due to the presence of sulfuric acid in inductively coupled plasma mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

García-Poyo, M. Carmen; Grindlay, Guillermo; Gras, Luis [Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, P.O. Box 99, 03080 – Alicante (Spain); Loos-Vollebregt, Margaretha T.C. de, E-mail: margaretha.deloos@ugent.be [Delft University of Technology, Faculty of Applied Sciences, Analytical Biotechnology, Julianalaan 67, 2628 BC Delft (Netherlands); Ghent University, Department of Analytical Chemistry, Krijgslaan 281 - S12, 9000 Ghent (Belgium); Mora, Juan, E-mail: juan.mora@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, P.O. Box 99, 03080 – Alicante (Spain)

2015-03-01

Results of a systematic study concerning non-spectral interferences from sulfuric acid containing matrices on a large number of elements in inductively coupled plasma–mass spectrometry (ICP-MS) are presented in this work. The signals obtained with sulfuric acid solutions of different concentrations (up to 5% w w{sup −1}) have been compared with the corresponding signals for a 1% w w{sup −1−} nitric acid solution at different experimental conditions (i.e., sample uptake rates, nebulizer gas flows and r.f. powers). The signals observed for {sup 128}Te{sup +}, {sup 78}Se{sup +} and {sup 75}As{sup +} were significantly higher when using sulfuric acid matrices (up to 2.2-fold for {sup 128}Te{sup +} and {sup 78}Se{sup +} and 1.8-fold for {sup 75}As{sup +} in the presence of 5 w w{sup -1} sulfuric acid) for the whole range of experimental conditions tested. This is in agreement with previously reported observations. The signal for {sup 31}P{sup +} is also higher (1.1-fold) in the presence of sulfuric acid. The signal enhancements for {sup 128}Te{sup +}, {sup 78}Se{sup +}, {sup 75}As{sup +} and {sup 31}P{sup +} are explained in relation to an increase in the analyte ion population as a result of charge transfer reactions involving S{sup +} species in the plasma. Theoretical data suggest that Os, Sb, Pt, Ir, Zn and Hg could also be involved in sulfur-based charge transfer reactions, but no experimental evidence has been found. The presence of sulfuric acid gives rise to lower ion signals (about 10–20% lower) for the other nuclides tested, thus indicating the negative matrix effect caused by changes in the amount of analyte loading of the plasma. The elemental composition of a certified low-density polyethylene sample (ERM-EC681K) was determined by ICP-MS after two different sample digestion procedures, one of them including sulfuric acid. Element concentrations were in agreement with the certified values, irrespective of the acids used for the digestion. These

Electrical characterization of proton conducting polymer electrolyte based on bio polymer with acid dopant

Energy Technology Data Exchange (ETDEWEB)

Kalaiselvimary, J.; Pradeepa, P.; Sowmya, G.; Edwinraj, S.; Prabhu, M. Ramesh, E-mail: email-mkram83@gmail.com [Department of Physics, Alagappa University, Karaikudi – 630 004, India. (India)

2016-05-06

This study describes the biodegradable acid doped films composed of chitosan and Perchloric acid with different ratios (2.5 wt %, 5 wt %, 7.5 wt %, 10 wt %) was prepared by the solution casting technique. The temperature dependence of the proton conductivity of complex electrolytes obeys the Arrhenius relationship. Proton conductivity of the prepared polymer electrolyte of the bio polymer with acid doped was measured to be approximately 5.90 × 10{sup −4} Scm{sup −1}. The dielectric data were analyzed using Complex impedance Z*, Dielectric loss ε’, Tangent loss for prepared polymer electrolyte membrane with the highest conductivity samples at various temperature.

High Mass-Loading of Sulfur-Based Cathode Composites and Polysulfides Stabilization for Rechargeable Lithium/Sulfur Batteries

International Nuclear Information System (INIS)

Hara, Toru; Konarov, Aishuak; Mentbayeva, Almagul; Kurmanbayeva, Indira; Bakenov, Zhumabay

2015-01-01

Although sulfur has a high theoretical gravimetric capacity, 1672 mAh/g, its insulating nature requires a large amount of conducting additives: this tends to result in a low mass-loading of active material (sulfur), and thereby, a lower capacity than expected. Therefore, an optimal choice of conducting agents and of the method for sulfur/conducting-agent integration is critically important. In this paper, we report that the areal capacity of 4.9 mAh/cm 2 was achieved at sulfur mass loading of 4.1 mg/cm 2 by casting sulfur/polyacrylonitrile/ketjenblack (S/PAN/KB) cathode composite into carbon fiber paper. This is the highest value among published/reported ones even though it does not contain expensive nanosized carbon materials such as carbon nanotubes, graphene, or graphene derivatives, and competitive enough with the conventional LiCoO 2 -based cathodes (e.g., LiCoO 2 , <20 mg/cm 2 corresponding to <2.8 mAh/cm 2 ). Furthermore, the combination of sulfur/PAN-based composite and PAN-based carbon fiber paper enabled the sulfur-based composite to be used even in carbonate-based electrolyte solution that many lithium/sulfur battery researchers avoid the use of it because of severer irreversible active material loss than in electrolyte solutions without carbonate-based solutions, and even at the highest mass-loading ever reported (the more sulfur is loaded, the more decomposed sulfides deposit at an anode surface).

Corrosion by concentrated sulfuric acid in carbon steel pipes and tanks: state of the art

Energy Technology Data Exchange (ETDEWEB)

Panossian, Zehbour; Almeida, Neusvaldo Lira de; Sousa, Raquel Maria Ferreira de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Pimenta, Gutemberg de Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento (CENPES); Marques, Leandro Bordalo Schmidt [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)

2009-07-01

PETROBRAS, allied to the policy of reduction of emission of pollutants, has been adjusting the processes of the new refineries to obtain products with lower sulfur content. Thus, the sulfur dioxide, extracted from the process gases of a new refinery to be built in the Northeast, will be used to produce sulfuric acid with concentration between (94-96) %. This acid will be stored in carbon steel tanks and transported through a buried 8-km carbon steel pipe from the refinery to a pier, where it will be loaded onto ships and sent to the consumer markets. Therefore, the corrosion resistance of carbon steel by concentrated acid will become a great concern for the mentioned storage and transportation. When the carbon steel comes into contact with concentrated sulfuric acid, there is an immediate acid attack with the formation of hydrogen gas and ferrous ions which, in turn, forms a protective layer of FeSO{sub 4} on the metallic surface. The durability of the tanks and pipes made of carbon steel will depend on the preservation of this protective layer. This work presents a review of the carbon steel corrosion in concentrated sulfuric acid and discusses the preventive methods against this corrosion, including anodic protection. (author)

ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

Energy Technology Data Exchange (ETDEWEB)

Gorensek, M.; Edwards, T.

2009-06-11

A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

Directory of Open Access Journals (Sweden)

Iurii S. Bodachivskyi

2016-12-01

Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.

Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array

International Nuclear Information System (INIS)

Kramer, Kirsten E.; Rose-Pehrsson, Susan L.; Hammond, Mark H.; Tillett, Duane; Streckert, Holger H.

2007-01-01

Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO 2 , H 2 S, and CS 2 in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO 2 , H 2 S, and CS 2 , respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO 2 , H 2 S, and CS 2 , respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for

Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array.

Science.gov (United States)

Kramer, Kirsten E; Rose-Pehrsson, Susan L; Hammond, Mark H; Tillett, Duane; Streckert, Holger H

2007-02-12

Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO(2), H(2)S, and CS(2) in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO(2), H(2)S, and CS(2), respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO(2), H(2)S, and CS(2), respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for

Coulometric titration of niobium in 1F sulfuric acid

International Nuclear Information System (INIS)

Pannu, S.S.

1975-01-01

A coulometric titration at constant current has been devised for Nb in 1F sulfuric acid. The titration was based on the oxidation of Nb(III) to Nb(V) by Fe(III) electrogenerated at a graphite anode. Both potentiometric and amperometric end points were used. The Nb(V) was prior reduced at a mercury cathode by exhaustive electrolysis at a current density of 15 ma/mc 2 for at least 10 hr. Ta,V,Ti and a working platinum anode interfered, but the separation of the potentials of Nb(V)/Nb(III) and Ti(IV)/Ti(III) permitted the titration of first Nb and then Ti. The average error for the titration of 0.30 to 13.00 mg of niobium in 100 ml of 1F sulfuric acid was + 0.57%. (author)

Unique aqueous Li-ion/sulfur chemistry with high energy density and reversibility.

Science.gov (United States)

Yang, Chongyin; Suo, Liumin; Borodin, Oleg; Wang, Fei; Sun, Wei; Gao, Tao; Fan, Xiulin; Hou, Singyuk; Ma, Zhaohui; Amine, Khalil; Xu, Kang; Wang, Chunsheng

2017-06-13

Leveraging the most recent success in expanding the electrochemical stability window of aqueous electrolytes, in this work we create a unique Li-ion/sulfur chemistry of both high energy density and safety. We show that in the superconcentrated aqueous electrolyte, lithiation of sulfur experiences phase change from a high-order polysulfide to low-order polysulfides through solid-liquid two-phase reaction pathway, where the liquid polysulfide phase in the sulfide electrode is thermodynamically phase-separated from the superconcentrated aqueous electrolyte. The sulfur with solid-liquid two-phase exhibits a reversible capacity of 1,327 mAh/(g of S), along with fast reaction kinetics and negligible polysulfide dissolution. By coupling a sulfur anode with different Li-ion cathode materials, the aqueous Li-ion/sulfur full cell delivers record-high energy densities up to 200 Wh/(kg of total electrode mass) for >1,000 cycles at ∼100% coulombic efficiency. These performances already approach that of commercial lithium-ion batteries (LIBs) using a nonaqueous electrolyte, along with intrinsic safety not possessed by the latter. The excellent performance of this aqueous battery chemistry significantly promotes the practical possibility of aqueous LIBs in large-format applications.

A phenyl-sulfonic acid anchored carbon-supported platinum catalyst for polymer electrolyte fuel cell electrodes

International Nuclear Information System (INIS)

Selvarani, G.; Sahu, A.K.; Choudhury, N.A.; Sridhar, P.; Pitchumani, S.; Shukla, A.K.

2007-01-01

A method, to anchor phenyl-sulfonic acid functional groups with the platinum catalyst supported onto a high surface-area carbon substrate, is reported. The use of the catalyst in the electrodes of a polymer electrolyte fuel cell (PEFC) helps enhancing its performance. Characterization of the catalyst by Fourier transform infra red (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and point-of-zero-charge (PZC) studies suggests that the improvement in performance of the PEFC is facilitated not only by enlarging the three-phase boundary in the catalyst layer but also by providing ionic-conduction paths as well as by imparting negative charge to platinum sites with concomitant oxidation of sulfur present in the carbon support. It is argued that the negatively charged platinum sites help repel water facilitating oxygen to access the catalyst sites. The PEFC with modified carbon-supported platinum catalyst electrodes exhibits 40% enhancement in its power density as compared to the one with unmodified carbon-supported platinum catalyst electrodes

The roles of sulfuric acid in new particle formation and growth in the mega-city of Beijing

Directory of Open Access Journals (Sweden)

D. L. Yue

2010-05-01

Full Text Available Simultaneous measurements of gaseous sulfuric acid and particle number size distributions were performed to investigate aerosol nucleation and growth during CAREBeijing-2008. The analysis of the measured aerosols and sulfuric acid with an aerosol dynamic model shows the dominant role of sulfuric acid in new particle formation (NPF process but also in the subsequent growth in Beijing. Based on the data of twelve NPF events, the average formation rates (2–13 cm⁻³ s⁻¹ show a linear correlation with the sulfuric acid concentrations (R²=0.85. Coagulation seems to play a significant role in reducing the number concentration of nucleation mode particles with the ratio of the coagulation loss to formation rate being 0.41±0.16. The apparent growth rates vary from 3 to 11 nm h⁻¹. Condensation of sulfuric acid and its subsequent neutralization by ammonia and coagulation contribute to the apparent particle growth on average 45±18% and 34±17%, respectively. The 30% higher concentration of sulfate than organic compounds in particles during the seven sulfur-rich NPF events but 20% lower concentration of sulfate during the five sulfur-poor type suggest that organic compounds are an important contributor to the growth of the freshly nucleated particles, especially during the sulfur-poor cases.

Lithium Azide as an Electrolyte Additive for All-Solid-State Lithium-Sulfur Batteries.

Science.gov (United States)

Eshetu, Gebrekidan Gebresilassie; Judez, Xabier; Li, Chunmei; Bondarchuk, Oleksandr; Rodriguez-Martinez, Lide M; Zhang, Heng; Armand, Michel

2017-11-27

Of the various beyond-lithium-ion battery technologies, lithium-sulfur (Li-S) batteries have an appealing theoretical energy density and are being intensely investigated as next-generation rechargeable lithium-metal batteries. However, the stability of the lithium-metal (Li°) anode is among the most urgent challenges that need to be addressed to ensure the long-term stability of Li-S batteries. Herein, we report lithium azide (LiN 3 ) as a novel electrolyte additive for all-solid-state Li-S batteries (ASSLSBs). It results in the formation of a thin, compact and highly conductive passivation layer on the Li° anode, thereby avoiding dendrite formation, and polysulfide shuttling. It greatly enhances the cycling performance, Coulombic and energy efficiencies of ASSLSBs, outperforming the state-of-the-art additive lithium nitrate (LiNO 3 ). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tetrathionate and Elemental Sulfur Shape the Isotope Composition of Sulfate in Acid Mine Drainage

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Nurgul Balci

2017-08-01

Full Text Available Sulfur compounds in intermediate valence states, for example elemental sulfur, thiosulfate, and tetrathionate, are important players in the biogeochemical sulfur cycle. However, key understanding about the pathways of oxidation involving mixed-valance state sulfur species is still missing. Here we report the sulfur and oxygen isotope fractionation effects during the oxidation of tetrathionate (S4O62− and elemental sulfur (S° to sulfate in bacterial cultures in acidic conditions. Oxidation of tetrathionate by Acidithiobacillus thiooxidans produced thiosulfate, elemental sulfur and sulfate. Up to 34% of the tetrathionate consumed by the bacteria could not be accounted for in sulfate or other intermediate-valence state sulfur species over the experiments. The oxidation of tetrathionate yielded sulfate that was initially enriched in 34S (ε34SSO4−S4O6 by +7.9‰, followed by a decrease to +1.4‰ over the experiment duration, with an average ε34SSO4−S4O6 of +3.5 ± 0.2‰ after a month of incubation. We attribute this significant sulfur isotope fractionation to enzymatic disproportionation reactions occurring during tetrathionate decomposition, and to the incomplete transformation of tetrathionate into sulfate. The oxygen isotope composition of sulfate (δ18OSO4 from the tetrathionate oxidation experiments indicate that 62% of the oxygen in the formed sulfate was derived from water. The remaining 38% of the oxygen was either inherited from the supplied tetrathionate, or supplied from dissolved atmospheric oxygen (O2. During the oxidation of elemental sulfur, the product sulfate became depleted in 34S between −1.8 and 0‰ relative to the elemental sulfur with an average for ε34SSO4−S0 of −0.9 ± 0.2‰ and all the oxygen atoms in the sulfate derived from water with an average normal oxygen isotope fractionation (ε18OSO4−H2O of −4.4‰. The differences observed in δ18OSO4 and the sulfur isotope composition of sulfate (δ34SSO4

Acid-Base and Electrolyte Disorders in Patients with and without Chronic Kidney Disease: An Update.

Science.gov (United States)

Dhondup, Tsering; Qian, Qi

2017-12-01

Kidneys play a pivotal role in the maintenance and regulation of acid-base and electrolyte homeostasis, which is the prerequisite for numerous metabolic processes and organ functions in the human body. Chronic kidney diseases compromise the regulatory functions, resulting in alterations in electrolyte and acid-base balance that can be life-threatening. In this review, we discuss the renal regulations of electrolyte and acid-base balance and several common disorders including metabolic acidosis, alkalosis, dysnatremia, dyskalemia, and dysmagnesemia. Common disorders in chronic kidney disease are also discussed. The most recent and relevant advances on pathophysiology, clinical characteristics, diagnosis, and management of these conditions have been incorporated.

Electrolytic decontamination of stainless steel using a basic electrolyte

International Nuclear Information System (INIS)

Childs, E.L.; Long, J.L.

1981-01-01

An electrolytic plutonium decontamination process or stainless steel was developed for use as the final step in a proposed radioactive waste handling and decontamination facility to be construced at the Rockwell International Rocky Flats plutonium handling facility. This paper discusses test plan, which was executed to compare the basic electrolyte with phosphoric acid and nitric acid electrolytes. 1 ref

Continuos extraction of uranium and molibdenum by lixiviation with sulfuric acid

International Nuclear Information System (INIS)

Cripiani, M.

1980-01-01

A methodology for collecting data of uranium and molibdenum extraction by lixiviation with sulfuric acid is showed. Discontinuous tests of lixiviation, time influence, temperature, granulation, acid/ore relation, oxidant/ore relation and solid percentage are studied. (C.G.C.) [pt

Sugar Dehydration without Sulfuric Acid: No More Choking Fumes in the Classroom!

Science.gov (United States)

Silverstein, Todd P.; Zhang, Yi

1998-06-01

Sugar is a common reagent often used in colorful classroom demonstrations. It produces a growing column of black ash when dehydrated by concentrated sulfuric acid, and it produces a brilliant purple flame when combusted with potassium chlorate. Unfortunately, both of these reactions also produce copious quantities of noxious fumes which make them problematic as lecture demonstrations. We have modified and combined these two reactions. Our demonstration uses no sulfuric acid, yields relatively little smoke, and produces an exciting and unpredictable growing column of black carbon.

New Parameterizations for Neutral and Ion-Induced Sulfuric Acid-Water Particle Formation in Nucleation and Kinetic Regimes

Science.gov (United States)

Määttänen, Anni; Merikanto, Joonas; Henschel, Henning; Duplissy, Jonathan; Makkonen, Risto; Ortega, Ismael K.; Vehkamäki, Hanna

2018-01-01

We have developed new parameterizations of electrically neutral homogeneous and ion-induced sulfuric acid-water particle formation for large ranges of environmental conditions, based on an improved model that has been validated against a particle formation rate data set produced by Cosmics Leaving OUtdoor Droplets (CLOUD) experiments at European Organization for Nuclear Research (CERN). The model uses a thermodynamically consistent version of the Classical Nucleation Theory normalized using quantum chemical data. Unlike the earlier parameterizations for H2SO4-H2O nucleation, the model is applicable to extreme dry conditions where the one-component sulfuric acid limit is approached. Parameterizations are presented for the critical cluster sulfuric acid mole fraction, the critical cluster radius, the total number of molecules in the critical cluster, and the particle formation rate. If the critical cluster contains only one sulfuric acid molecule, a simple formula for kinetic particle formation can be used: this threshold has also been parameterized. The parameterization for electrically neutral particle formation is valid for the following ranges: temperatures 165-400 K, sulfuric acid concentrations 104-1013 cm-3, and relative humidities 0.001-100%. The ion-induced particle formation parameterization is valid for temperatures 195-400 K, sulfuric acid concentrations 104-1016 cm-3, and relative humidities 10-5-100%. The new parameterizations are thus applicable for the full range of conditions in the Earth's atmosphere relevant for binary sulfuric acid-water particle formation, including both tropospheric and stratospheric conditions. They are also suitable for describing particle formation in the atmosphere of Venus.

Hydrolysis of Pentosan for Furfural Preparing Using Sulfuric Acid Catalyst to Improve Diesel Engine Fuel Quality

International Nuclear Information System (INIS)

Setyadji, Moch

2007-01-01

The investigation on furfural preparation from peanut shell using sulfuric acid catalyst has been done. Furfural is an organic solvent used in industry especially petroleum industry. The purpose of this investigation is to know the effects of sulfuric acid concentration and solvent feed ratio towards furfural resulted and the reaction kinetics. The experiment was performed in the batch reactor. The result of this investigation showed that the process optimum condition was reached at sulfuric acid concentration of 7% and the solvent feed ratio of 12.5. The result at the optimum condition above was 5.97% of furfural. The relation between percentage of furfural resulted (Y) and sulfuric acid concentration (X) is Y = 0.893 X 1.7023 . e -0.2554X with average deviation of 5.880 %. The relation between percentage of furfural resulted (Y) and solvent feed ratio (X) is Y = -53.0411 + 9.4137 X - 0.3780 X 2 with average deviation 5.154 %. The relation between reaction rate constant (Y) and sulfuric acid concentration (X) is Y = 3.1916 . 10 -3 + 8.2432 . 10 -3 X - 5.2324 . 10 -4 X 2 with average deviation 8.024 %. (author)

Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

CERN Document Server

Rondo, L.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

2016-01-01

Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF(Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

New unit for sulfuric acid alkylation of isobutane by olefins

Energy Technology Data Exchange (ETDEWEB)

Khadzhiev, S.N.; Baiburskii, V.L.; Deineko, P.S.; Gruzdev, A.S.; Tagavov, I.T.

1987-01-01

The authors describe and illustrate a sulfuric acid alkylation unit with a horizontal contact. As a result of the use of this design solution, the isobutane/olefin ratio is 10/1 in comparison with 4/1 to 5/1 in the other types of units, namely vertical reactors and cascade tank reactors. The unit was designed to process the butane-butylene cut (BBC) and part of the propane-propylene cut (PPC) from the G-43-107 cat cracker. The unit design includes provisions for controlled caustic washing of the feed and dehydration in an electric field. The authors present the basic data obtained in the three months of unit operation after startup, in comparison with the operating indexes of a sulfuric acid alkylation unit.

Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach.

Science.gov (United States)

Jiménez, José Víctor; Carrillo-Pérez, Diego Luis; Rosado-Canto, Rodrigo; García-Juárez, Ignacio; Torre, Aldo; Kershenobich, David; Carrillo-Maravilla, Eduardo

2017-08-01

Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

Sulfur Amino Acids in Diet-induced Fatty Liver: A New Perspective Based on Recent Findings

Directory of Open Access Journals (Sweden)

John I. Toohey

2014-06-01

Full Text Available The relationship of sulfur amino acids to diet-induced fatty liver was established 80 years ago, with cystine promoting the condition and methionine preventing it. This relationship has renewed importance today because diet-induced fatty liver is relevant to the current epidemics of obesity, non-alcoholic fatty liver disease, metabolic syndrome, and type 2 diabetes. Two recent papers provide the first evidence linking sulfane sulfur to diet-induced fatty liver opening a new perspective on the problem. This review summarizes the early data on sulfur amino acids in fatty liver and correlates that data with current knowledge of sulfur metabolism. Evidence is reviewed showing that the lipotropic effect of methionine may be mediated by sulfane sulfur and that the hepatosteatogenic effect of cystine may be related to the removal of sulfane sulfur by cysteine catabolites. Possible preventive and therapeutic strategies are discussed.

FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID REMOVAL

Energy Technology Data Exchange (ETDEWEB)

Gary M. Blythe

2004-01-01

The objective of this project has been to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project was co-funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corporation, the Tennessee Valley Authority, and Carmeuse North America. Sulfuric acid controls are becoming of increased interest for coal-fired power generating units for a number of reasons. In particular, sulfuric acid can cause plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NOX control, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project tested the effectiveness of furnace injection of four different magnesium-based or dolomitic alkaline sorbents on full-scale utility boilers. These reagents were tested during one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide slurry byproduct from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercially available magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners. The other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm sorbent effectiveness over extended operation on two

Charged and Neutral Binary Nucleation of Sulfuric Acid in Free Troposphere Conditions

OpenAIRE

Duplissy, Jonathan; Merikanto, Joonas; Sellegri, Karine; Rose, Clemence; Asmi, Eija; Freney, Evelyn; Juninen, Heikki; Sipilä, Mikko; Vehkamaki, Hanna; Kulmala, Markku

2013-01-01

We present a data set of binary nucleation of sulfuric acid and water, measured in the CLOUD chamber at CERN during the CLOUD3 and CLOUD5 campaigns. Four parameters have been varied to cover neutral and ion-induced binary nucleation processes: Sulfuric acid concentration (1e5 to 1e8 molecules per cm^(−3)), relative humidity (10% to 80%), temperature (208-293K) and ion concentration (0-4000 ions per cm^(−3)). In addition, classical nucleation theory implemented with hydrates and ion induced nu...

Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes.

Science.gov (United States)

Zeng, ZhenHua; Björketun, Mårten E; Ebbesen, Sune; Mogensen, Mogens B; Rossmeisl, Jan

2013-05-14

The mechanisms governing the sulfur poisoning of the triple phase boundary (TPB) of Ni-XSZ (X2O3 stabilized zirconia) anodes have been investigated using density functional theory. The calculated sulfur adsorption energies reveal a clear correlation between the size of the cation dopant X(3+) and the sulfur tolerance of the Ni-XSZ anode; the smaller the ionic radius, the higher the sulfur tolerance. The mechanistic study shows that the size of X(3+) strongly influences XSZ's surface energy, which in turn determines the adhesion of Ni to XSZ. The Ni-XSZ interaction has a direct impact on the Ni-S interaction and on the relative stability of reconstructed and pristine Ni(100) facets at the TPB. Together, these two effects control the sulfur adsorption on the Ni atoms at the TPB. The established relationships explain experimentally observed dopant-dependent anode performances and provide a blueprint for the future search for and preparation of highly sulfur tolerant anodes.

Double Soft-Template Synthesis of Nitrogen/Sulfur-Codoped Hierarchically Porous Carbon Materials Derived from Protic Ionic Liquid for Supercapacitor.

Science.gov (United States)

Sun, Li; Zhou, Hua; Li, Li; Yao, Ying; Qu, Haonan; Zhang, Chengli; Liu, Shanhu; Zhou, Yanmei

2017-08-09

Heteroatom-doped hierarchical porous carbon materials derived from the potential precursors and prepared by a facile, effective, and low-pollution strategy have recently been particularly concerned in different research fields. In this study, the interconnected nitrogen/sulfur-codoped hierarchically porous carbon materials have been successfully obtained via one-step carbonization of the self-assembly of [Phne][HSO 4 ] (a protic ionic liquid originated from dilute sulfuric acid and phenothiazine by a straightforward acid-base neutralization) and the double soft-template of OP-10 and F-127. During carbonization process, OP-10 as macroporous template and F-127 as mesoporous template were removed, while [Phne][HSO 4 ] not only could be used as carbon, nitrogen, and sulfur source, but also as a pore forming agent to create micropores. The acquired carbon materials for supercapacitor not only hold a large specific capacitance of 302 F g -1 even at 1.0 A g -1 , but also fine rate property with 169 F g -1 at 10 A g -1 and excellent capacitance retention of nearly 100% over 5000 circulations in 6 M KOH electrolyte. Furthermore, carbon materials also present eximious rate performance with 70% in 1 M Na 2 SO 4 electrolyte.

Phenol-Sulfuric Acid Method for Total Carbohydrates

Science.gov (United States)

Nielsen, S. Suzanne

The phenol-sulfuric acid method is a simple and rapid colorimetric method to determine total carbohydrates in a sample. The method detects virtually all classes of carbohydrates, including mono-, di-, oligo-, and polysaccharides. Although the method detects almost all carbohydrates, the absorptivity of the different carbohydrates varies. Thus, unless a sample is known to contain only one carbohydrate, the results must be expressed arbitrarily in terms of one carbohydrate.

Research and development on process components for hydrogen production. (1) Test-fabrication of sulfuric acid transfer pump

International Nuclear Information System (INIS)

Iwatsuki, Jin; Terada, Atsuhiko; Hino, Ryutaro; Kubo, Shinji; Onuki, Kaoru; Watanabe, Yutaka

2009-01-01

Japan Atomic Energy Agency has been conducting a research and development on hydrogen production system using High Temperature Gas-Cooled Reactor. As a part of this effort, thermochemical water-splitting cycle featuring iodine- and sulfur-compounds (IS process) is under development considering its potential of large-scale economical hydrogen production. The IS process constitutes very severe environments to the materials of construction because of the corrosive nature of process chemicals, especially of the high temperature acidic solutions of sulfuric acid and hydriodic acid dissolving iodine. Therefore, selection of the corrosion-resistant materials and development of the components have been the crucial subjects of process development. This paper concerns the sulfuric acid transfer pump. The development has been implemented of a pump for transporting concentrated sulfuric acid at temperatures of higher than 300degC and at elevated pressure. Recent progress of these activities will be reported. (author)

Application of acoustic agglomeration for removing sulfuric acid mist from air stream

Directory of Open Access Journals (Sweden)

Asghar Sadighzadeh

2018-01-01

Full Text Available The application of acoustic fields at high sound pressure levels (SPLs for removing sulfuric acid mists from the air stream was studied. An acoustic agglomeration chamber was used to conduct the experiments. The studied SPLs ranged from 115 to 165 decibel (dB, with three inlet concentrations of acid mist at 5–10, 15–20, and 25–30 ppm. The air flow rates for conducting experiments were 20, 30, and 40 L min−1. The concentration of sulfuric acid mist was measured using US Environmental Protection Agency Method 8 at inlet and outlet of the chamber. The resonance frequencies for experiments were found to be 852, 1410, and 3530 Hz. The maximum acoustic agglomeration efficiency of 86% was obtained at optimum frequency of 852 Hz. The analysis of variance test revealed significant differences between agglomeration efficiency at three resonance frequencies (p-value < 0.001. The maximum acoustic agglomeration efficiency was obtained at SPL level of 165 dB. High initial concentrations of acid mists and lower air flow rates enhance the acoustic agglomeration of mists. High removal efficiency of acid mists from air stream could be achieved by the application of acoustic agglomeration method with appropriate range of frequencies and SPLs. Keywords: Sulfuric acid, Mist, Acoustic agglomeration, SPL

Separation of aliphatic carboxylic acids and benzenecarboxylic acids by ion-exclusion chromatography with various cation-exchange resin columns and sulfuric acid as eluent.

Science.gov (United States)

Ohta, Kazutoku; Ohashi, Masayoshi; Jin, Ji-Ye; Takeuchi, Toyohide; Fujimoto, Chuzo; Choi, Seong-Ho; Ryoo, Jae-Jeong; Lee, Kwang-Pill

2003-05-16

The application of various hydrophilic cation-exchange resins for high-performance liquid chromatography (sulfonated silica gel: TSKgel SP-2SW, carboxylated silica gel: TSKgel CM-2SW, sulfonated polymethacrylate resin: TSKgel SP-5PW, carboxylated polymethacrylate resins: TSKgel CM-5PW and TSKgel OA-Pak A) as stationary phases in ion-exclusion chromatography for C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, butyric, isovaleric, valeric, isocaproic, caproic, 2-methylhexanoic and heptanoic acids) and benzenecarboxylic acids (pyromellitic, trimellitic, hemimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic, salicylic acids and phenol) was carried out using diluted sulfuric acid as the eluent. Silica-based cation-exchange resins (TSKgel SP-2SW and TSKgel CM-2SW) were very suitable for the ion-exclusion chromatographic separation of these benzenecarboxylic acids. Excellent simultaneous separation of these benzenecarboxylic acids was achieved on a TSKgel SP-2SW column (150 x 6 mm I.D.) in 17 min using a 2.5 mM sulfuric acid at pH 2.4 as the eluent. Polymethacrylate-based cation-exchange resins (TSKgel SP-5PW, TSKgel CM-5PW and TSKgel OA-Pak A) acted as advanced stationary phases for the ion-exclusion chromatographic separation of these C1-C7 aliphatic carboxylic acids. Excellent simultaneous separation of these C1-C7 acids was achieved on a TSKgel CM-5PW column (150 x 6 mm I.D.) in 32 min using a 0.05 mM sulfuric acid at pH 4.0 as the eluent.

Insight into the loading temperature of sulfur on sulfur/carbon cathode in lithium-sulfur batteries

International Nuclear Information System (INIS)

Ye, Huan; Yin, Ya-Xia; Guo, Yu-Guo

2015-01-01

Highlights: • A cost-effective chemical activation method to prepare porous carbon nanospheres. • Carbon nanospheres with bimodal microporous structure show high specific area and large micropore volume. • The S/C composite cathodes with in-situformed S−C bond exhibit high sulfur activity with a reversible capacity of 1000 mA h g −1 . • S−C bond enables well confinement on sulfur and polysulfides. - Abstract: Lithium–sulfur batteries are highly desired because of their characteristics such as high energy density. However, the applications of Li-S batteries are limited because they exist dissolution of polysulfides into electrolytes. This study reports the preparation of sulfur cathodes by using bimodal microporous (0.5 nm and 0.8 nm to 2.0 nm) carbon spheres with high specific area (1992 m 2 g −1 ) and large micropore volume (1.2 g cm −1 ), as well as the encapsulation of polysulfides via formation of carbon–sulfur bonds in a sealed vacuum glass tube at high temperature. Given that sulfur and polysulfides are well confined by the S−C bond, the shuttle effect is effectively suppressed. The prepared S/C cathodes with a sulfur loading of up to 75% demonstrate high sulfur activity with reversible capacity of 1000 mA h g −1 at the current density of 0.1 A g −1 and good cycling stability (667 mA h g −1 after 100 cycles).

The effect of solvent component on the discharge performance of Lithium-sulfur cell containing various organic electrolytes

International Nuclear Information System (INIS)

Kim, Seok; Jung, Yongju; Lim, Hong S.

2004-01-01

The effect of solvent component on the discharge performance of lithium-sulfur (Li/S) cell and the optimal composition of ternary electrolyte for the improved discharge performance of the cell have been investigated. The capacity value and capacity stability with cycle are dependent on the nature of solvent as well as the composition of mixed solvent. The change trend of discharge performance as a function of content of each solvent component is studied. Capacity value increases as the 1,3-dioxolane (DOX) content decreases. Average discharge voltage shows larger value when the 1,2-dimethoxy ethane (DME) content is small. Finally, we have obtained the optimal solvent composition by using a statistical method

Method for the treatment of mining gangue containing sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Minnick, L J; Smith, C L; Webster, W C

1976-07-01

Mining gangue is often heaped up on large, open-air dumps. By means of extraction and oxidation of the sulfuric elements contained, the environment is being negatively influenced, due to the sulfuric acids occuring. The method described converts the gangue into an ecologically agreeable material which can be used even in road construction. This is achieved by mixing the gangue with lime, a pozzolane active material and water, and by hardening the gangue at atmospheric pressure for several days. This method can be very cost-effective if fly ash is used as pozzolane-active material.

Changes in the levels of major sulfur metabolites and free amino acids in pea cotyledons recovering from sulfur deficiency

International Nuclear Information System (INIS)

Macnicol, P.K.; Randall, P.J.

1987-01-01

Changes in levels of sulfur metabolites and free amino acids were followed in cotyledons of sulfur-deficient, developing pea seeds (Pisum sativum L.) for 24 hours after resupply of sulfate, during which time the legumin mRNA levels returned almost to normal. Two recovery situations were studied: cultured seeds, with sulfate added to the medium, and seeds attached to the intact plant, with sulfate added to the roots. In both situations the levels of cysteine, glutathione, and methionine rose rapidly, glutathione exhibiting an initial lag. In attached but not cultured seeds methionine markedly overshot the level normally found in sulfur-sufficient seeds. In the cultured seed S-adenosylmethionine (AdoMet), but not S-methylmethionine, showed a sustained rise; in the attached seed the changes were slight. The composition of the free amino acid pool did not change substantially in either recovery situation. In the cultured seed the large rise in AdoMet level occurred equally in nonrecovering seeds. It was accompanied by 6-fold and 10-fold increases in γ-aminobutyrate and alanine, respectively. These effects are attributed to wounding resulting from excision of the seed. 35 S-labeling experiments showed that there was no significant accumulation of label in unidentified sulfur-containing amino compounds in either recovery situation. It was concluded from these results and those of other workers that, at the present level of knowledge, the most probable candidate for a signal compound, eliciting recovery of legumin mRNA level in response to sulfur-feeding, is cysteine

Pretreatment of Sugar Beet Pulp with Dilute Sulfurous Acid is Effective for Multipurpose Usage of Carbohydrates.

Science.gov (United States)

Kharina, M; Emelyanov, V; Mokshina, N; Ibragimova, N; Gorshkova, T

2016-05-01

Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent is the possibility of its regeneration. Application of sulfurous acid as hydrolyzing agent in relatively low concentrations (0.6-1.0 %) during a short period of time (10-20 min) and low solid to liquid ratio (1:3, 1:6) allowed effective extraction of carbohydrates from SBP and provided positive effect on subsequent enzymatic hydrolysis. The highest obtained concentration of reducing substances (RS) in hydrolysates was 8.5 %; up to 33.6 % of all carbohydrates present in SBP could be extracted. The major obtained monosaccharides were arabinose and glucose (9.4 and 7.3 g/l, respectively). Pretreatment of SBP with sulfurous acid increased 4.6 times the yield of glucose during subsequent enzymatic hydrolysis of remaining solids with cellulase cocktail, as compared to the untreated SBP. Total yield of glucose during SBP pretreatment and subsequent enzymatic hydrolysis amounted to 89.4 % of the theoretical yield. The approach can be applied directly to the wet SBP. Hydrolysis of sugar beet pulp with sulfurous acid is recommended for obtaining of individual monosaccharides, as well as nutritional media.

X-ray spectral determination of chemical state of phosphorus and sulfur in anodic oxide films on niobium

International Nuclear Information System (INIS)

Bokij, L.P.; Kostikov, Yu.P.

1989-01-01

Chemical forms of phosphorus and sulfur in niobium oxide anodic film, obtained by electrochemical technique using niobium in H 2 SO 4 and H 3 PO 4 aqueous solutions, are determined using data on chemical shifts of X-ray emission lines. Films represent Nb 2 O 5(1-γ) (SO 4 ) 5γ and Nb 2 O 5(1-γ) (PO 4 ) 10γ/3 (γ -share of oxygen substituted by acid anion) composition oxosalts. Electrolyte role in formation of niobium anodic oxide structure and effect of phosphorus and sulfur compounds on anodic film conductivity are determined

The role of ammonia in sulfuric acid ion induced nucleation

Directory of Open Access Journals (Sweden)

I. K. Ortega

2008-06-01

Full Text Available We have developed a new multi-step strategy for quantum chemical calculations on atmospherically relevant cluster structures that makes calculation for large clusters affordable with a good accuracy-to-computational effort ratio. We have applied this strategy to evaluate the relevance of ternary ion induced nucleation; we have also performed calculations for neutral ternary nucleation for comparison. The results for neutral ternary nucleation agree with previous results, and confirm the important role of ammonia in enhancing the growth of sulfuric acid clusters. On the other hand, we have found that ammonia does not enhance the growth of ionic sulfuric acid clusters. The results also confirm that ion-induced nucleation is a barrierless process at high altitudes, but at ground level there exists a barrier due to the presence of a local minimum on the free energy surface.

Amine reactivity with charged sulfuric acid clusters

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B. R. Bzdek

2011-08-01

Full Text Available The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS. Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge, both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia is also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO₄(H₂SO_4x]⁻ and [(NH_4x(HSO_4x+1(H₂SO₄₃]⁻. Dimethylamine substitution for ammonia in [(NH_{4 x}(HSO_{4 x+1}(H₂SO₄₃]⁻ clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H₂SO₄ to bisulfate is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO₄ (H₂SO_{4 x}]⁻ clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (>m/z 400, whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2–3 orders of magnitude slower than incorporation of dimethylamine either by substitution or addition

A dual coaxial nanocable sulfur composite for high-rate lithium-sulfur batteries.

Science.gov (United States)

Li, Zhen; Yuan, Lixia; Yi, Ziqi; Liu, Yang; Xin, Ying; Zhang, Zhaoliang; Huang, Yunhui

2014-01-01

Lithium-sulfur batteries have great potential for some high energy applications such as in electric vehicles and smart grids due to their high capacity, natural abundance, low cost and environmental friendliness. But they suffer from rapid capacity decay and poor rate capability. The problems are mainly related to the dissolution of the intermediate polysulfides in the electrolyte, and to the poor conductivity of sulfur and the discharge products. In this work, we propose a novel dual coaxial nanocable sulfur composite fabricated with multi-walled nanotubes (MWCNT), nitrogen-doped porous carbon (NPC) and polyethylene glycol (PEG), i.e. MWCNTs@S/NPC@PEG nanocable, as a cathode material for Li-S batteries. In such a coaxial structure, the middle N-doped carbon with hierarchical porous structure provides a nanosized capsule to contain and hold the sulfur particles; the inner MWCNTs and the outer PEG layer can further ensure the fast electronic transport and prevent the dissolution of the polysulfides into the electrolyte, respectively. The as-designed MWCNT@S/NPC@PEG composite shows good cycling stability and excellent rate capability. The capacity is retained at 527 mA h g(-1) at 1 C after 100 cycles, and 791 mA h g(-1) at 0.5 C and 551 mA h g(-1) at 2 C after 50 cycles. Especially, the high-rate capability is outstanding with 400 mA h g(-1) at 5 C.

Battery recycling: recovery of manganese in the form of electrolytic manganese dioxide

International Nuclear Information System (INIS)

Roriz, Elizabeth Rodrigues Rangel; Von Krüge, Paulo; Espinosa, Denise Crocce Romano; Tenorio, Jorge Alberto Soares

2010-01-01

This work seeks to verify the possibility of using depleted batteries as a source of manganese applying the electrolytic process, considering the growing demand for products containing manganese in their composition. It was used an electrolyte solution containing the metal ions: Ca (270mg / L), Ni (3000 mg / L), Co (630 mg / L), Mn (115.300 mg / L) , Ti (400 mg / L) and Pb (20 mg / L) in concentrated sulfuric acid. The production of electrolytic manganese dioxide (EMD) was performed through galvanization using a stabilized source that monitored the potential of the working electrode. It was used an electrode of lead and two counter electrodes of graphite at a temperature of 98 deg C (± 2 deg C) and current density of 1.69A.dm"-"2. The material obtained was analyzed through the process of X-ray fluorescence spectrometry and X-ray diffraction. The results indicated that it is possible to obtain electrolytic manganese dioxide with a purity of about 94% and that the main allotropic variety obtained under the conditions of the experiment was the ε-MnO_2. (author)

Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

KAUST Repository

Kravitz, Ben

2009-07-28

We used a general circulation model of Earth\\'s climate to conduct geoengineering experiments involving stratospheric injection of sulfur dioxide and analyzed the resulting deposition of sulfate. When sulfur dioxide is injected into the tropical or Arctic stratosphere, the main additional surface deposition of sulfate occurs in midlatitude bands, because of strong cross-tropopause flux in the jet stream regions. We used critical load studies to determine the effects of this increase in sulfate deposition on terrestrial ecosystems by assuming the upper limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2 into the tropical stratosphere or 3 Tg of SO2 into the Arctic stratosphere, neither the maximum point value of sulfate deposition of approximately 1.5 mEq m−2 a−1 nor the largest additional deposition that would result from geoengineering of approximately 0.05 mEq m−2 a−1 is enough to negatively impact most ecosystems.

Sulfuric acid deposition from stratospheric geoengineering with sulfate aerosols

KAUST Repository

Kravitz, Ben; Robock, Alan; Oman, Luke; Stenchikov, Georgiy L.; Marquardt, Allison B.

2009-01-01

We used a general circulation model of Earth's climate to conduct geoengineering experiments involving stratospheric injection of sulfur dioxide and analyzed the resulting deposition of sulfate. When sulfur dioxide is injected into the tropical or Arctic stratosphere, the main additional surface deposition of sulfate occurs in midlatitude bands, because of strong cross-tropopause flux in the jet stream regions. We used critical load studies to determine the effects of this increase in sulfate deposition on terrestrial ecosystems by assuming the upper limit of hydration of all sulfate aerosols into sulfuric acid. For annual injection of 5 Tg of SO2 into the tropical stratosphere or 3 Tg of SO2 into the Arctic stratosphere, neither the maximum point value of sulfate deposition of approximately 1.5 mEq m−2 a−1 nor the largest additional deposition that would result from geoengineering of approximately 0.05 mEq m−2 a−1 is enough to negatively impact most ecosystems.

Use of probabilistic safety analysis for design of emergency mitigation systems in hydrogen producer plant with sulfur-iodine technology, Section II: sulfuric acid decomposition

International Nuclear Information System (INIS)

Mendoza A, A.; Nelson E, P. F.; Francois L, J. L.

2009-10-01

Over the last decades, the need to reduce emissions of greenhouse gases has prompted the development of technologies for the production of clean fuels through the use of primary energy resources of zero emissions, as the heat of nuclear reactors of high temperature. Within these technologies, one of the most promising is the hydrogen production by sulfur-iodine cycle coupled to a high temperature reactor initially proposed by General Atomics. By their nature and because it will be large-scale plants, the development of these technologies from its present phase to its procurement and construction, will have to incorporate emergency mitigation systems in all its parts and interconnections to prevent undesired events that could put threaten the plant integrity and the nearby area. For the particular case of sulfur-iodine thermochemical cycle, most analysis have focused on hydrogen explosions and failures in the primary cooling systems. While these events are the most catastrophic, is that there are also many other events that even taking less direct consequences, could jeopardize the plant operation, the people safety of nearby communities and carry the same economic consequences. In this study we analyzed one of these events, which is the formation of a toxic cloud prompted by uncontrolled leakage of concentrated sulfuric acid in the second section of sulfur-iodine process of General Atomics. In this section, the sulfuric acid concentration is near to 90% in conditions of high temperature and positive pressure. Under these conditions the sulfuric acid and sulfur oxides from the reactor will form a toxic cloud that the have contact with the plant personnel could cause fatalities, or to reach a town would cause suffocation, respiratory problems and eye irritation. The methodology used for this study is the supported design in probabilistic safety analysis. Mitigation systems were postulated based on the isolation of a possible leak, the neutralization of a pond of

Enhanced performance of ultracapacitors using redox additive-based electrolytes

Science.gov (United States)

Jain, Dharmendra; Kanungo, Jitendra; Tripathi, S. K.

2018-05-01

Different concentrations of potassium iodide (KI) as redox additive had been added to 1 M sulfuric acid (H2SO4) electrolyte with an aim of enhancing the capacitance and energy density of ultracapacitors via redox reactions at the interfaces of electrode-electrolyte. Ultracapacitors were fabricated using chemically treated activated carbon as electrode with H2SO4 and H2SO4-KI as an electrolyte. The electrochemical performances of fabricated supercapacitors were investigated by impedance spectroscopy, cyclic voltammetry and charge-discharge techniques. The maximum capacitance ` C' was observed with redox additives-based electrolyte system comprising 1 M H2SO4-0.3 M KI (1072 F g- 1), which is very much higher than conventional 1 M H2SO4 (61.3 F g- 1) aqueous electrolyte-based ultracapacitors. It corresponds to an energy density of 20.49 Wh kg- 1 at 2.1 A g- 1 for redox additive-based electrolyte, which is six times higher as compared to that of pristine electrolyte (1 M H2SO4) having energy density of only 3.36 Wh kg- 1. The temperature dependence behavior of fabricated cell was also analyzed, which shows increasing pattern in its capacitance values in a temperature range of 5-70 °C. Under cyclic stability test, redox electrolyte-based system shows almost 100% capacitance retention up to 5000 cycles and even more. For comparison, ultracapacitors based on polymer gel electrolyte polyvinyl alcohol (PVA) (10 wt%)—{H2SO4 (1 M)-KI (0.3 M)} (90 wt%) have been fabricated and characterized with the same electrode materials.

Effect of Silica Sol on Boric-sulfuric Acid Anodic Oxidation of LY12CZ Aluminum Alloy

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LIU Hui-cong

2016-07-01

Full Text Available Aluminum alloy anodizing coatings were prepared for LY12CZ in the boric-sulfuric acid solution (45g/L sulfuric acid,8g/L boric acid with the addition of 10%,20%,30% (volume fractionsilica sol,with the gradient voltage of 15V. The current and voltage transients of the anodizing process were collected by data collection instrument. The surface morphologies,microstructure and chemical composition of the anodic coatings were characterized by scanning electron microscopy (SEM. The corrosion resistance was examined by neutral salt spray,electrochemical impedance spectroscopy (EIS test and titrating test. The results show that the different concentration of silica sol addition can influence the forming and dissolution of anodizing coatings,improve the compactness smoothness and corrosion resistance during the anodizing process in the boric-sulfuric acid solution.

New insights into sulfur amino acids function in gut health and disease

Science.gov (United States)

The gastrointestinal tract (GIT) is a metabolically significant site of sulfur amino acids (SAAs) metabolism in the body. Aside from their role in protein synthesis, methionine and cysteine are involved in many biological functions and diseases. Methionine (MET) is an indispensable amino acid and is...

A Li+-conductive microporous carbon–sulfur composite for Li-S batteries

International Nuclear Information System (INIS)

Zhang, Wenhua; Qiao, Dan; Pan, Jiaxin; Cao, Yuliang; Yang, Hanxi; Ai, Xinping

2013-01-01

Highlights: ► A carbon–sulfur composite was prepared by vaporizing sulfur into the nanopores of Li + -conductive carbon microspheres. ► The redox reaction of S 8 molecules embedded in the nanopores of carbon microspheres proceeds through a solid–solid mechanism at the S/C interfaces. ► The carbon–sulfur composite exhibits a stable cycling performance and a superior high coulombic efficiency of 100%. - Abstract: In this paper, we propose a new strategy to develop high performance sulfur electrode by impregnating sulfur into the micropores of a Li + -insertable carbon matrix with the simultaneous use of a carbonate electrolyte, which does not dissolve polysulfides, to restrain the solution of the reaction intermediates of sulfur. To proof this concept, we prepared a Li + -insertable microporous carbon–sulfur composite by vaporizing sulfur into the micropores of the nanofiber-wired carbon microspheres. The experimental results demonstrate that, in the carbonate electrolyte of 1 M LiPF 6 /PC-EC-DEC, such S/C composite electrode exhibits not only stable cycling performance with a reversible capacity of 720 mAh g −1 after 100 cycles, but also superior high coulombic efficiency of ∼100% upon extended cycling (except the first three cycles). The structural and electrochemical analysis indicates that the improved electrochemical behaviors of the S/C composite arise from a new reaction mechanism, in which Li + ions and electrons transport through the carbon matrix into the interior of the cathode and then react with the embedded sulfur in the S/C solid–solid interfaces, avoiding the solution of the intermediates into the bulk electrolyte. More significantly, the structural design and working mechanism of such a sulfur cathode could be extended to a variety of poorly conductive and easily soluble redox-active materials for battery applications.

submitter Unexpectedly acidic nanoparticles formed in dimethylamine–ammonia–sulfuric-acid nucleation experiments at CLOUD

CERN Document Server

Lawler, Michael J; Kim, Jaeseok; Ahlm, Lars; Tröstl, Jasmin; Praplan, Arnaud P; Schobesberger, Siegfried; Kürten, Andreas; Kirkby, Jasper; Bianchi, Federico; Duplissy, Jonathan; Hansel, Armin; Jokinen, Tuija; Keskinen, Helmi; Lehtipalo, Katrianne; Leiminger, Markus; Petäjä, Tuukka; Rissanen, Matti; Rondo, Linda; Simon, Mario; Sipilä, Mikko; Williamson, Christina; Wimmer, Daniela; Riipinen, Ilona; Virtanen, Annele; Smith, James N

2016-01-01

New particle formation driven by acid–base chemistry was initiated in the CLOUD chamber at CERN by introducing atmospherically relevant levels of gas-phase sulfuric acid and dimethylamine (DMA). Ammonia was also present in the chamber as a gas-phase contaminant from earlier experiments. The composition of particles with volume median diameters (VMDs) as small as 10 nm was measured by the Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS). Particulate ammonium-to-dimethylaminium ratios were higher than the gas-phase ammonia-to-DMA ratios, suggesting preferential uptake of ammonia over DMA for the collected 10–30 nm VMD particles. This behavior is not consistent with present nanoparticle physicochemical models, which predict a higher dimethylaminium fraction when NH3 and DMA are present at similar gas-phase concentrations. Despite the presence in the gas phase of at least 100 times higher base concentrations than sulfuric acid, the recently formed particles always had measured base : ...

Properties of nanocellulose isolated from corncob residue using sulfuric acid, formic acid, oxidative and mechanical methods.

Science.gov (United States)

Liu, Chao; Li, Bin; Du, Haishun; Lv, Dong; Zhang, Yuedong; Yu, Guang; Mu, Xindong; Peng, Hui

2016-10-20

In this work, nanocellulose was extracted from bleached corncob residue (CCR), an underutilized lignocellulose waste from furfural industry, using four different methods (i.e. sulfuric acid hydrolysis, formic acid (FA) hydrolysis, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation, and pulp refining, respectively). The self-assembled structure, morphology, dimension, crystallinity, chemical structure and thermal stability of prepared nanocellulose were investigated. FA hydrolysis produced longer cellulose nanocrystals (CNCs) than the one obtained by sulfuric acid hydrolysis, and resulted in high crystallinity and thermal stability due to its preferential degradation of amorphous cellulose and lignin. The cellulose nanofibrils (CNFs) with fine and individualized structure could be isolated by TEMPO-mediated oxidation. In comparison with other nanocellulose products, the intensive pulp refining led to the CNFs with the longest length and the thickest diameter. This comparative study can help to provide an insight into the utilization of CCR as a potential source for nanocellulose production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adsorption properties and porous structure of sulfuric acid treated bentonites determined - SHORT COMMUNICATION

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SNEZANA BREZOVSKA

2005-02-01

Full Text Available In a previous paper adsorption isotherms of benzene vapor on natural bentonite from Ginovci, Macedonia, and forms acid activated with 10 % and 15 % solutions of hydrochloric were interpreted by means of the Dubinin–Radushkevich–Stoeckli and Dubinin–Astakhov equations; the investigation has been continued with bentonites acid activated with 10 % and 15 % solutions of sulfuric acid where X-ray analysis indicates smaller structural changes. Using the above equations, the heterogeneity of the micropores and the energetic heterogeneity of the bentonites were determined from the differential distribution of the micropore volume with respect to the structural parameter of the equations characterizing the microporous structure and to the molar free energy of adsorption. Activated bentonites obtain bigger pores but also a certain quantity of new small pores appear during acid activation with the higher concentration of acid. The micropore volumes, determined from the adsorption of benzene vapor, of bentonites activated with 10 % and 15 % solution of hydrochloric acid (144.60 cm3 kg-1 and 110.06 cm3 kg-1, respectively, decrease in comparison with that of natural bentonite (162.55 cm3 kgv.1 In contrast, the values of the micropore volume for bentonities treated with 10 % and 15 % solutions of sulfuric acids increase (169.19 cm3 kg-1 and 227.74 cm3 kg-1. That is due to the difference in the structural changes occurring during activation with hydrochloric and sulfuric acids. The values of the free energy of adsorption of benzene vapor for natural bentonite are higher than those of the acid acitivated bentonities, what is in accordance with the structural and porosity changes.

The incidence of electrolyte and acid-base abnormalities in critically ...

African Journals Online (AJOL)

Background: Electrolytes and acid-base disorders are common challenges seen in the intensive care unit (ICU) resulting in difficulty in weaning patients off the ventilator, prolonged admission periods, preventable cardiac arrhythmias and cardiac arrest. These require prompt lab results most of which are done serially, ...

Determination of uranium content in phosphoric and sulfuric acids used by the phosphatized fertilizers industry

International Nuclear Information System (INIS)

Ramos, M.M.O.

1984-05-01

Uranium content in phosphoric and sulfuric acids is determined. The uranium was measured through the fission track registration technique, using Makrofol KG, 10 μg thick, as detector. The so-called 'wet' method was adopted and the acid samples were used directly as irradiation medium. This proceeding showed the advantages of simple sample preparation and avoided the need of changing the acid samples media to nitric medium, as commonly used. The analysis of the sulfuric acid samples showed uranium contents under the detection limit of the technique (4 ppb). The results found for phosphoric acid samples ranged from 31 to 845 ppm, with experimental errors between 7.9 and 9.7%. (Author) [pt

Separation of hafnium from zirconium in sulfuric acid solutions using pressurized ion exchange

International Nuclear Information System (INIS)

Hurst, F.J.

1981-01-01

High-resolution pressurized ion exchange has been used successfully to study and separate hafnium and zirconium sulfate complexes by chromatographic elution from Dowex 50W-X8 (15 to 25 μm) resin with sulfuric acid solutions. Techniques were developed to continuously monitor the column effluents for zirconium and hafnium by reaction with fluorometric and colorimetric reagents. Since neither reagent was specific for either metal ion, peak patterns were initially identified by using the stable isotopes 90 Zr and 180 Hf as fingerprints of their elution position. Distribution ratios for both zirconium and hafnium decrease as the inverse fourth power of the sulfuric acid concentration below 2N and as the inverse second power at higher acid concentration. The hafnium-to-zirconium separation factor is approximately constant (approx. 8) over the 0.5 to 3N range. Under certain conditions, an unseparated fraction was observed that was not retained by the resin. The amount of this fraction which is thought to be a polymeric hydrolysis product appears to be a function of metal and sulfuric acid concentrations. Conditions are being sought to give the highest zirconium concentration and the lowest acid concentration that can be used as a feed material for commercial scale-up in the continuous annular chromatographic (CAC) unit without formation of the polymer

Assessment of nanofiltration and reverse osmosis potentialities to recover metals, sulfuric acid, and recycled water from acid gold mining effluent.

Science.gov (United States)

Ricci, Bárbara C; Ferreira, Carolina D; Marques, Larissa S; Martins, Sofia S; Amaral, Míriam C S

This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (∼100%), was observed, while metals were retained with high efficiencies (∼90%), whereas RO led to high acid rejections (acid solutions contaminated by metals, such as POX effluent. In this context, a purified acid stream could be recovered in NF permeate, which could be further concentrated in RO. Recovered acid stream could be reused in the gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water.

Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries.

Science.gov (United States)

Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

2016-09-07

As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications.

High-performance electrolyte in the presence of dextrose and its derivatives for aluminum electrolytic capacitors

Science.gov (United States)

Tsai, Ming-Liao; Lu, Yi-Fang; Do, Jing-Shan

Dextrose and its derivatives (e.g. glucose, gluconic acid and gluconic lactone) are added to modify the characteristics of electrolytes used in aluminum electrolytic capacitors. The results show that the conductivity and sparking voltage of the electrolytes are severely affected by the concentration of dextrose gluconic acid and gluconic lactone. In addition, the pH of the electrolyte is only slightly affected by the quantity of gluconic acid and gluconic lactone. The capacitance, dissipation factor, and leakage current of capacitors impregnated with the electrolytes prepared in this work are periodically measured under storage conditions and loading at 105 °C.

Capacity Fade Analysis of Sulfur Cathodes in Lithium–Sulfur Batteries

Science.gov (United States)

Yan, Jianhua; Liu, Xingbo

2016-01-01

Rechargeable lithium–sulfur (Li–S) batteries are receiving ever‐increasing attention due to their high theoretical energy density and inexpensive raw sulfur materials. However, their rapid capacity fade has been one of the key barriers for their further improvement. It is well accepted that the major degradation mechanisms of S‐cathodes include low electrical conductivity of S and sulfides, precipitation of nonconductive Li2S2 and Li2S, and poly‐shuttle effects. To determine these degradation factors, a comprehensive study of sulfur cathodes with different amounts of electrolytes is presented here. A survey of the fundamentals of Li–S chemistry with respect to capacity fade is first conducted; then, the parameters obtained through electrochemical performance and characterization are used to determine the key causes of capacity fade in Li–S batteries. It is confirmed that the formation and accumulation of nonconductive Li2S2/Li2S films on sulfur cathode surfaces are the major parameters contributing to the rapid capacity fade of Li–S batteries. PMID:27981001

Study on de-coating used beverage cans with thick sulfuric acid for recycle

International Nuclear Information System (INIS)

Wang, Minghua; Woo, Kee-Do; Kim, Dong-Keon; Ma, Lirong

2007-01-01

More than 1800 hundreds of millions of beverage cans are manufactured yearly over the world, which will pollute the globe environment without recycle. The recycle and regeneration estates of used beverage cans are highly profitable enterprises. Vacuum technologies are mature on a large scale today, and therefore, the re-melting process of used beverage cans (UBCs) does not have to use flux. Furthermore, the coating on UBCs becomes the key factor causing poor product quality. The present paper concerns removing the coating of UBCs and compares two different kinds of methods to remove the coating: a thermal method and a chemical reagent method. A new kind of reagent, thick sulfuric acid, was employed in the chemical reagent de-coating process. The de-coating ratio in the thermal method reached 93% at most, but the de-coating ratio reached 100% within 30 min in the chemical reagent method by using thick sulfuric acid. Recycling the used thick sulfuric acid was also supplied. A titanium yellow product can be simultaneously obtained. The experiments show that the chemical reagent method is more available than the thermal method, which will enhance the purity of the regeneration product enormously

Comparison of Xe single bubble sonoluminescence in water and sulfuric acid

International Nuclear Information System (INIS)

An Yu

2008-01-01

Using the equations of fluid mechanics with proper boundary conditions and taking account of the gas properties, we can numerically simulate the process of single bubble sonoluminescence, in which electron–neutral atom bremsstrahlung, electron—ion bremsstrahlung and recombination radiation, and the radiative attachment of electrons to atoms and molecules contribute to the light emission. The calculation can quantitatively or qualitatively interpret the experimental results. We find that the accumulated heat energy inside the compressed gas bubble is mostly consumed by the chemical reaction, therefore, the maximum degree of ionization inside Xe bubble in water is much lower than that in sulfuric acid, of which the vapour pressure is very low. In addition, in sulfuric acid much larger p a and R 0 are allowed which makes the bubbles in it much brighter than that in water. (classical areas of phenomenology)

High-temperature extraction of rhenium from sulfuric acid solutions with trialkylamines

International Nuclear Information System (INIS)

Gladyhev, V.P.; Andreeva, N.N.; Kim, E.M.; Kovaleva, S.V.

1985-01-01

This paper attempts to determine the possibility of conducting high-temperature extraction of rhenium from sulfuric acid solutions with trialkylamines (TAA) using higher hydrocarbon-paraffin mixtures as the diluent of the extraction system. Substitution of kerosene by paraffin in the extraction system would permit decreasing the danger of fire and explosions during he extraction process. In extracting rhenium from industrial solutions with a melt of higher paraffins containing TAA and alcohols, the extraction system can be continously heated in heat exchangers through which washing sulfuric acid passes and then goes to the extractor. This permits utilizing the heat and decreases the temperature of the solutions for extraction to the optimum temperatures. Extraction of rhenium with a melt of trioctylamine in paraffin obeys the same mechanisms as high-temperature extraction of ruthenium (IV) by amines in kerosene and aromatic hydrocarbons

Reuse of Anode Slime Generated by the Zinc Industry to Obtain a Liquor for Manufacturing Electrolytic Manganese

Science.gov (United States)

Ayala, J.; Fernández, B.

2013-08-01

A hydrometallurgical process is proposed in this article to recover manganese from a zinc electrowinning residue. The article describes the digestion-leaching experiments, precipitation, and electrowinning assays to recover Mn from this residue. Anode slime is treated with sulfuric acidic in a furnace within a temperature range of 400-450°C, leached with water, and then filtered. The results show that the dissolution of manganese increases with increasing temperature in the digestion step. The recovery yield of manganese was higher than 90%. As manganese electrolysis requires an electrolyte free of Zn, Ni, Co, and Cu pollutants, the sulfuric acid liquor needs a purification step. Na2S is used to remove pollutants. The results obtained in this study have shown that the proposed process for the recovery of manganese from this type of residue is technically viable.

Origin of electrolyte-dopant dependent sulfur poisoning of SOFC anodes

DEFF Research Database (Denmark)

Zeng, Zhenhua; Björketun, Mårten E; Ebbesen, Sune

2013-01-01

The mechanisms governing the sulfur poisoning of the triple phase boundary (TPB) of Ni-XSZ (X2O3 stabilized zirconia) anodes have been investigated using density functional theory. The calculated sulfur adsorption energies reveal a clear correlation between the size of the cation dopant X3...

Lead-Free Sn-Ce-O Composite Coating on Cu Produced by Pulse Electrodeposition from an Aqueous Acidic Sulfate Electrolyte

Science.gov (United States)

Sharma, Ashutosh; Das, Karabi; Das, Siddhartha

2017-10-01

Pulse-electrodeposited Sn-Ce-O composite solder coatings were synthesized on a Cu substrate from an aqueous acidic solution containing stannous sulfate (SnSO4·3H2O), sulfuric acid (H2SO4), and Triton X-100 as an additive. The codeposition was achieved by adding nano-cerium oxide powder in varying concentrations from 5 g/L to 20 g/L into the electrolytic bath. Microstructural characterization was carried out using x-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy. The XRD analysis showed that the deposits consist mainly of tetragonal β (Sn) with reduced cerium oxide species. The composite coatings thus obtained exhibit a smaller grain size, possess higher microhardness, and a lower melting point than the monolithic Sn coating. The electrical resistivity of the developed composites increases, however, but lies within the permissible limits for current lead-free solder applications. Also, an optimum balance of properties in terms of microhardness, adhesion, melting point and resistivity can be obtained with 0.9 wt.% cerium oxide in the Sn matrix, which enables potential applications in solder joints and packaging.

Comparison of sulfuric and hydrochloric acids as catalysts in hydrolysis of Kappaphycus alvarezii (cottonii).

Science.gov (United States)

Meinita, Maria Dyah Nur; Hong, Yong-Ki; Jeong, Gwi-Taek

2012-01-01

In this study, hydrolysis of marine algal biomass Kappaphhycus alvarezii using two different acid catalysts was examined with the goal of identifying optimal reaction conditions for the formation of sugars and by-products. K. alvarezii were hydrolyzed by autoclave using sulfuric acid or hydrochloric acid as catalyst with different acid concentrations (0.1-1.0 M), substrate concentrations (1.0-13.5%), hydrolysis time (10-90 min) and hydrolysis temperatures (100-130 (°)C). A difference in galactose, glucose, reducing sugar and total sugar content was observed under the different hydrolysis conditions. Different by-product compounds such as 5-hydroxymethylfurfural and levulinic acid were also observed under the different reaction conditions. The optimal conditions for hydrolysis were achieved at a sulfuric acid concentration, temperature and reaction time of 0.2 M, 130 °C and 15 min, respectively. These results may provide useful information for the development of more efficient systems for biofuel production from marine biomass.

Electrodeposition of compact zinc from the hydrophobic Brønsted acidic ionic liquid-based electrolytes and the study of zinc stability along with the acidity manipulation

International Nuclear Information System (INIS)

Chen, Yi-Han; Yeh, Hsin-Wen; Lo, Nai-Chang; Chiu, Chen-Wei; Sun, I-Wen; Chen, Po-Yu

2017-01-01

Highlights: • Compact Zn with no crack is deposited from protic ionic liquid-based electrolytes. • The ionic liquid is composed of the protonated betaine ion. • This ionic liquid is hydrophobic and zinc oxide is soluble in it. • The effects of co-solvents, propylene carbonate and water, are studied. • The Zn stripping/deposition efficiency can be manipulated via acidity adjustment. - Abstract: Compact crystalline zinc was electrodeposited on stainless-steel electrode (SS) via potentiostatic/galvanostatic electrolysis from the hydrophobic Brønsted acidic ionic liquid, protonated betaine bis((trifluoromethyl)sulfonyl)imide (IL [Hbet][TFSI]), −based electrolytes containing ZnCl 2 or ZnO under argon or ambient air atmosphere. Approximate 10 wt% of propylene carbonate and water, respectively, were used as the co-solvents for [Hbet][TFSI] to form the IL-based electrolytes. The efficiency of zinc deposition/stripping, which is significantly affected by the Brønsted acidity of the IL-based electrolytes, was studied at glassy carbon electrode (GC) to evaluate the stability of the zinc electrodeposits along with the electrolyte acidity. The stability is very poor for the zinc electrodeposits obtained from ZnCl 2 solution. However, it increases with increasing the quantity of ZnO or urea in the electrolytes; the former neutralize the dissociable protons in [Hbet] cations to form water, and the latter may form H-bonding with [Hbet] or be protonated to form the weakly acidic cations [HUrea]. Both suppress the reaction between the Zn electrodeposits and protons. The stability of the Zn electrodeposits, therefore, can be improved via the manipulation of the IL acidity.

Low temperature sulfur and sodium metal battery for grid-scale energy storage application

Science.gov (United States)

Liu, Gao; Wang, Dongdong

2018-03-27

A re-chargeable battery comprising a non-dendrite forming sodium (Na)/potassium (K) liquid metal alloy anode, a sulfur and polyacrylonitrile (PAN) conductive polymer composite cathode, a polyethyleneoxide (PEO) solid electrolyte, a solid electrolyte interface (SEI) formed on the PEO solid electrolyte; and a cell housing, wherein the anode, cathode, and electrolyte are assembled into the cell housing with the PEO solid electrolyte disposed between the cathode and anode.

Online Automatic Titration of Chromic Acid in Chromium Plating Solutions and Phosphoric and Sulfuric Acids in Electropolishing Solutions

National Research Council Canada - National Science Library

Sopok, Samuel

1991-01-01

.... The analytical chemistry literature lacks an adequate online automatic titration method for the monitoring of chromic acid in chromium plating solutions and the monitoring of phosphoric and sulfuric...

Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

Science.gov (United States)

Edward L. Springer; John F. Harris

1982-01-01

Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

STARCH SULFURIC ACID: AN ALTERNATIVE, ECO-FRIENDLY CATALYST FOR BIGINELLI REACTION

Directory of Open Access Journals (Sweden)

Ramin Rezaei

2013-12-01

Full Text Available The one-pot multicomponent synthesis of 3,4-dihydropyrimidinone derivatives using starch sulfuric acid as an environmentally friendly biopolymer-based solid acid catalyst from aldehydes, β-keto esters and urea/ thiourea without solvent is described. Compared with classical Biginelli reaction conditions, this new method has the advantage of minimizing the cost operational hazards and environmental pollution, good yields, shorter reaction times and simple work-up.

Inhibition of Enzymatic Browning of Chlorogenic Acid by Sulfur-Containing Compounds

NARCIS (Netherlands)

Kuijpers, T.F.M.; Narvaez Cuenca, C.E.; Vincken, J.P.; Verloop, J.W.; Berkel, van W.J.H.; Gruppen, H.

2012-01-01

The antibrowning activity of sodium hydrogen sulfite (NaHSO3) was compared to that of other sulfur-containing compounds. Inhibition of enzymatic browning was investigated using a model browning system consisting of mushroom tyrosinase and chlorogenic acid (5-CQA). Development of brown color

Dynamic behavior of the bray-liebhafsky oscillatory reaction controlled by sulfuric acid and temperature

Science.gov (United States)

Pejić, N.; Vujković, M.; Maksimović, J.; Ivanović, A.; Anić, S.; Čupić, Ž.; Kolar-Anić, Lj.

2011-12-01

The non-periodic, periodic and chaotic regimes in the Bray-Liebhafsky (BL) oscillatory reaction observed in a continuously fed well stirred tank reactor (CSTR) under isothermal conditions at various inflow concentrations of the sulfuric acid were experimentally studied. In each series (at any fixed temperature), termination of oscillatory behavior via saddle loop infinite period bifurcation (SNIPER) as well as some kind of the Andronov-Hopf bifurcation is presented. In addition, it was found that an increase of temperature, in different series of experiments resulted in the shift of bifurcation point towards higher values of sulfuric acid concentration.

Sulfuric acid baking and leaching of spent Co-Mo/Al2O3 catalyst.

Science.gov (United States)

Kim, Hong-In; Park, Kyung-Ho; Mishra, Devabrata

2009-07-30

Dissolution of metals from a pre-oxidized refinery plant spent Co-Mo/Al(2)O(3) catalyst have been tried through low temperature (200-450 degrees C) sulfuric acid baking followed by mild leaching process. Direct sulfuric acid leaching of the same sample, resulted poor Al and Mo recoveries, whereas leaching after sulfuric acid baking significantly improved the recoveries of above two metals. The pre-oxidized spent catalyst, obtained from a Korean refinery plant found to contain 40% Al, 9.92% Mo, 2.28% Co, 2.5% C and trace amount of other elements such as Fe, Ni, S and P. XRD results indicated the host matrix to be poorly crystalline gamma- Al(2)O(3). The effect of various baking parameters such as catalyst-to-acid ratio, baking temperature and baking time on percentage dissolutions of metals has been studied. It was observed that, metals dissolution increases with increase in the baking temperature up to 300 degrees C, then decreases with further increase in the baking temperature. Under optimum baking condition more than 90% Co and Mo, and 93% Al could be dissolved from the spent catalyst with the following leaching condition: H(2)SO(4)=2% (v/v), temperature=95 degrees C, time=60 min and Pulp density=5%.

Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. 1. Preliminary experiments in controlled shaken flasks

Energy Technology Data Exchange (ETDEWEB)

Dugan, P.R.

1987-01-01

Changes of pH and sulfate concentration in high-sulfur coal refuse slurries are used as measurements of microbial pyrite oxidation in the laboratory. Sodium lauryl sulfate (SLS), alkylbenzene sulfonate (ABS), benzoic acid (BZ) and combinations of SLS plus BZ and ABS plus BZ effectively inhibited formation of sulfate and acid when added in concentrations greater than 50 mg/l to inoculated 20 or 30% coal refuse slurries. Here 25 mg/l concentrations of SLS, ABS and ABS plus BZ stimulated acid production. Formic, hexanoic, oxalic, propionic, and pyruvic acids at 0.1% concentrations were also effective inhibitors. Four different lignin sulfonates were only slightly effective inhibitors at 0.1% concentrations. It was concluded that acid formation resulting from microbial oxidation in high-sulfur coal refuse can be inhibited. 22 references.

Influence of liquid and gas flow rates on sulfuric acid mist removal from air by packed bed tower

Directory of Open Access Journals (Sweden)

Jafari Mohammad Javad

2012-12-01

Full Text Available Abstract The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as three liquid flow rates, while other influencing parameters were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s, the average removal efficiency increased significantly (p 3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream.

Sulfuric acid and hydrogen peroxide surface passivation effects on AlGaN/GaN high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Zaidi, Z. H., E-mail: zaffar.zaidi@sheffield.ac.uk; Lee, K. B.; Qian, H.; Jiang, S.; Houston, P. A. [Department of Electronic and Electrical Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Guiney, I.; Wallis, D. J.; Humphreys, C. J. [Department of Materials Science and Metallurgy, The University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2014-12-28

In this work, we have compared SiN{sub x} passivation, hydrogen peroxide, and sulfuric acid treatment on AlGaN/GaN HEMTs surface after full device fabrication on Si substrate. Both the chemical treatments resulted in the suppression of device pinch-off gate leakage current below 1 μA/mm, which is much lower than that for SiN{sub x} passivation. The greatest suppression over the range of devices is observed with the sulfuric acid treatment. The device on/off current ratio is improved (from 10{sup 4}–10{sup 5} to 10{sup 7}) and a reduction in the device sub-threshold (S.S.) slope (from ∼215 to 90 mV/decade) is achieved. The sulfuric acid is believed to work by oxidizing the surface which has a strong passivating effect on the gate leakage current. The interface trap charge density (D{sub it}) is reduced (from 4.86 to 0.90 × 10{sup 12 }cm{sup −2} eV{sup −1}), calculated from the change in the device S.S. The gate surface leakage current mechanism is explained by combined Mott hopping conduction and Poole Frenkel models for both untreated and sulfuric acid treated devices. Combining the sulfuric acid treatment underneath the gate with the SiN{sub x} passivation after full device fabrication results in the reduction of D{sub it} and improves the surface related current collapse.

Sulfuric acid and hydrogen peroxide surface passivation effects on AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Zaidi, Z. H.; Lee, K. B.; Qian, H.; Jiang, S.; Houston, P. A.; Guiney, I.; Wallis, D. J.; Humphreys, C. J.

2014-01-01

In this work, we have compared SiN x passivation, hydrogen peroxide, and sulfuric acid treatment on AlGaN/GaN HEMTs surface after full device fabrication on Si substrate. Both the chemical treatments resulted in the suppression of device pinch-off gate leakage current below 1 μA/mm, which is much lower than that for SiN x passivation. The greatest suppression over the range of devices is observed with the sulfuric acid treatment. The device on/off current ratio is improved (from 10 4 –10 5 to 10 7 ) and a reduction in the device sub-threshold (S.S.) slope (from ∼215 to 90 mV/decade) is achieved. The sulfuric acid is believed to work by oxidizing the surface which has a strong passivating effect on the gate leakage current. The interface trap charge density (D it ) is reduced (from 4.86 to 0.90 × 10 12  cm −2 eV −1 ), calculated from the change in the device S.S. The gate surface leakage current mechanism is explained by combined Mott hopping conduction and Poole Frenkel models for both untreated and sulfuric acid treated devices. Combining the sulfuric acid treatment underneath the gate with the SiN x passivation after full device fabrication results in the reduction of D it and improves the surface related current collapse

Chemical stability of {gamma}-butyrolactone-based electrolytes for aluminium electrolytic capacitors

Energy Technology Data Exchange (ETDEWEB)

Ue, Makoto [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan); Takeda, Masayuki [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan); Suzuki, Yoko [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan); Mori, Shoichiro [Mitsubishi Chemical Corp., Tsukuba Research Center, Ibaraki (Japan)

1996-06-01

{gamma}-Butyrolactone-based electrolytes have been used as the operating electrolytes for aluminum electrolytic capacitors. The chemical stability of these electrolytes at elevated temperatures has been examined by monitoring the decrease in their electrolytic conductivities. The deteriorated electrolytes were analyzed by gas and liquid chromatography and the conductivity decrease was directly correlated with the loss of acid components. In quaternary ammonium hydrogen maleate/{gamma}-butyrolactone electrolytes, the maleate anion decomposed by decarboxylation resulting in a complex polymer containing polyester and polyacrylate structures. Quaternary ammonium benzoate/{gamma}-butyrolactone electrolytes decomposed by SN2 reactions giving alkyl benzoates and trialkylamines. The deterioration of the carboxylate salt/{gamma}-butyrolactone electrolytes was accelerated by electrolysis. (orig.)

Hydrogen production by electrochemical decomposition of formic acid via solid polymer electrolyte

Energy Technology Data Exchange (ETDEWEB)

Kilic, Ebru Oender [KOSGEB Bursa Business Development Center, Besevler Kucuk Sanayi Sitesi 16149 Nilufer/Bursa (Turkey); Koparal, Ali Savas; Oeguetveren, Uelker Bakir [Anadolu University, Iki Eylul Campus, Applied Research Center for Environmental Problems 26555 Eskisehir (Turkey); Anadolu University, Iki Eylul Campus, Department of Environmental Engineering, 26555 Eskisehir (Turkey)

2009-01-15

The aim of this work is to investigate the feasibility of simultaneous hydrogen production by electrochemical decomposition of formic acid via solid polymer electrolyte (SPE) in an electrochemical reactor. Titanium oxide coated with iridium oxide as anode and carbon fibre with Pt catalyst as cathode were used in the experiments. Effects of applied current density, flow rates and temperature of formic acid solution, concentration of supporting electrolyte and pH of the solution on performance of the process have been investigated. The effect of membrane thickness has also been examined. The results suggest that electrolysis using SPE is a promising method for the treatment of organic pollutants. Hydrogen with purity of 99.999% at ambient temperature by using carbon fibre cathode with Pt catalyst can be produced simultaneously and COD removal efficiency of 95% has been achieved not requiring any chemical addition and temperature increase. Also complete electrochemical oxidation of formic acid at the original pH to CO{sub 2} and H{sub 2}O without production of intermediate has been proved by HPLC analysis. (author)

Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. II. Inhibition in run of mine refuse under simulated field conditions

Energy Technology Data Exchange (ETDEWEB)

Dugan, P.R.

1987-01-01

The combination of sodium lauryl sulfate and benzoic acid effectively inhibits iron- and sulfur-oxidizing bacteria in coal refuse and prevents the conversion of iron pyrite to sulfate, ferric iron, and sulfuric acid, thereby significantly reducing the formation of acidic drainage from coal refuse. The inhibitors were effective in a concentration of 1.1. mg/kg refuse, and data indicate that the SLS was in excess of the concentration required. The treatment was compatible with the use of lime for neutralization of acid present prior to inhibition of its formation.

The extraction of zirconium (IV) from sulfuric acid solutions with high-molecular weight quaternary ammonium compound

International Nuclear Information System (INIS)

Sato, Taichi; Watanabe, Hiroshi

1982-01-01

The extraction of zirconium sulfate in aqueous sulfuric acid solutions with trioctylmethylammonium chloride (Aliquat-336; R 3 R'NCl) in organic solvents has been investigated under different conditions. In addition, the organic phases extracted sulfuric acid and zirconium sulfate were examined by IR and NMR spectroscopies. It has been found that Aliquat-336 extracts zirconium (IV) from sulfuric acid solutions according to the following ion-exchange reactions. i) The extraction of sulfuric acid is at first carried out through the equilibria, SO 4 2 - (aq) + 2R 3 R'NCl(org) reversible (R 3 R'N) 2 SO 4 (org) + 2Cl - (aq), (R 3 R'N) 2 SO 4 (org) + H + (aq) + HSO 4- (aq) reversible 2R 3 R'NHSO 4 (org). ii) The extraction of zirconium is expressed as the equilibrium reaction, Zr(SO 4 ) 3 2 - (aq) + 2xR 3 R'NHSO 4 (org) + (1-x)(R 3 R'N) 2 SO 4 (org) reversible (R 3 R'N) 2 [Zr(SO 4 ) 3 ](org) + xH 2 SO 4 (aq) + SO 4 2 - (aq), x = [R 3 R'NHSO 4 ]/(2[(R 3 R'N) 2 SO 4 ] + [R 3 R'NHSO 4 ]). Moreover, the hydrolyzed species (R 3 R'N)[ZrO(OH)(SO 4 )] is formed when zirconium is further extracted in an organic phase. (author)

The impact of uni-univalent electrolytes on (water + acetic acid + toluene) equilibria: Representation with electrolyte-NRTL model

International Nuclear Information System (INIS)

Saien, Javad; Fattahi, Mahdi; Mozafarvandi, Maryam

2014-01-01

Highlights: • Experimental LLE data for water + acetic acid + toluene + NaCl or KCl were reported. • The salting-out effect was detected; indicating the stronger effect of NaCl. • The electrolyte-NRTL model was adequately used to correlate the phase equilibria. • A good agreement was observed between calculated and experimental tie-lines. - Abstract: The presence of salts can significantly alter the (liquid + liquid) equilibrium and extraction process. In this work, a study was conducted on the (liquid + liquid) equilibria of (water + acetic acid + toluene + sodium chloride or potassium chloride) at temperatures (288.2, 298.2 and 313.2) K. This chemical system, irrespective of salt, is frequently used in (liquid + liquid) extraction investigations. The selected salt concentrations in initial aqueous solutions were (0.9 and 1.7) mol · L −1 . The results show that salting-out effect of the salts was significant, so that an enhancement in the acetic acid distribution coefficient was achieved within (15.6 to 66.8)% with NaCl and within (2.5 to 37.6)% with KCl. Meantime, high separation factors were found at low temperatures and low solute concentrations. The electrolyte-NRTL model was satisfactorily used to correlate the phase equilibria. In this regard for each salt, the temperature dependent binary interaction parameters between components were calculated. The predicted tie-line mole fractions give root-mean square deviation (RMSD) values of only 0.0038 and 0.0045 for the systems containing NaCl and KCl, respectively

Development of novel processes for Cu concentrates without producing sulfuric acid; Hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Nakamura, T; Noguchi, F; Takasu, T; Ito, H [Kyushu Inst. of Technology, Kitakyushu (Japan). Faculty of Engineering

1997-02-01

In the refining process for the production of copper from pyrites, heat treatment is carried out in a neutral atmosphere so that part of the sulphur will be collected in the form of simple sulfur and that pyrites naturally low in reactivity will be made active. A basic study is also conducted of a very high speed electrolytic method. The chemical aspects of pyrites which are various in composition (mainly CuFeS2) are clarified by X-ray diffraction, and then is subjected to heat-treatment in a 773K-1073K argon atmosphere. There is a decrease in the amount of sulfur at a temperatures not lower than 973K. The X-ray main diffraction line splits for the emergence of some lower angle diffraction lines. The specimen is then subjected to a leach test in a copper chloride base liquor, to disclose that leachability grows remarkably higher in the presence of a great change in the X-ray diffraction lattice constant. An experiment follows in which an electrolyte is allowed to flow at a high speed for accelerating the rate of electrolytic refining in an effort to prevent the passivation of anode and deposition of dendrite on the cathode that is apt to occur when the current density is high. Passivation is prevented when the flow rate is 10m/min or higher in the vicinity of the anode surface for the formation of a smooth electrodeposited surface. 2 refs., 2 figs., 2 tabs.

Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

Energy Technology Data Exchange (ETDEWEB)

Soleimani, Sahar, E-mail: ssoleima@connect.carleton.ca; Isgor, O. Burkan, E-mail: burkan_isgor@carleton.ca; Ormeci, Banu, E-mail: banu_ormeci@carleton.ca

2013-11-15

Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process.

Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

International Nuclear Information System (INIS)

Soleimani, Sahar; Isgor, O. Burkan; Ormeci, Banu

2013-01-01

Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process

Methanesulfonic acid solution as supporting electrolyte for zinc-vanadium redox battery

International Nuclear Information System (INIS)

Tang Chao; Zhou Debi

2012-01-01

Highlights: ► Methanesulfonic acid as supporting electrolyte for V(V)/V(IV) was discussed. ► V(V)/V(IV) concentration as high as 3 mol L −1 was obtained. ► A Zn-V battery was assembled. ► The assembled Zn-V battery has good cycle performance and high cell voltage. - Abstract: The present work was performed in order to evaluate methanesulfonic acid (MSA) as electrolyte medium for V(IV)/V(V) redox couple as positive species applied in redox flow battery (RFB). V-MSA solutions containing more than 3.0 mol L −1 vanadium ions were obtained. Conductivity and viscosity of 3.0 mol L −1 V(IV)/V(V) electrolyte were determined to be 0.10 cm s −1 and 12.37 mPa s respectively. Cyclic voltammetry was conducted to investigate the electrochemical behavior of V(IV)/V(V) redox couple. The diffusion coefficients of V(IV) on Pt electrode in 1.0, 2.0 and 3.0 mol L −1 V(IV)/V(V) electrolytes determined were 3.606 × 10 −6 , 1.813 × 10 −6 and 0.5244 × 10 −6 cm 2 s −1 , respectively. A Zn-V battery was assembled with V(IV)/V(V)-MSA positive species and Zn/Zn(II)-MSA negative species. The cell voltage in charged state was 1.9–2.0 V and discharge voltage reached up to 1.7 V. The average coulombic efficiency and energy efficiency of the assembled cell were 95.85% and 63.90% respectively and it showed a good cyclic charge–discharge performance, which indicates that MSA has a promise application prospect in vanadium redox battery.

Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

International Nuclear Information System (INIS)

Dong, Kang; Wang, Shengping; Zhang, Hanyu; Wu, Jinping

2013-01-01

Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al 2 O 3 can provide surface area for the deposition of Li 2 S and Li 2 S 2 . ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g −1 , and the remaining capacity was 585 mAh g −1 after 50 cycles at 0.25 mA cm −2 . Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process

The oxidation of organic additives in the positive vanadium electrolyte and its effect on the performance of vanadium redox flow battery

Science.gov (United States)

Nguyen, Tam D.; Whitehead, Adam; Scherer, Günther G.; Wai, Nyunt; Oo, Moe O.; Bhattarai, Arjun; Chandra, Ghimire P.; Xu, Zhichuan J.

2016-12-01

Despite many desirable properties, the vanadium redox flow battery is limited, in the maximum operation temperature that can be continuously endured, before precipitation begins in the positive electrolyte. Many additives have been proposed to improve the thermal stability of the charged positive electrolyte. However, we have found that the apparent stability, revealed in laboratory testing, is often simply an artifact of the test method and arises from the oxidation of the additive, with corresponding partial reduction of V(V) to V(IV). This does not improve the stability of the electrolyte in an operating system. Here, we examined the oxidation of some typical organic additives with carboxyl, alcohol, and multi-functional groups, in sulfuric acid solutions containing V(V). The UV-vis measurements and titration results showed that many compounds reduced the state-of-charge (SOC) of vanadium electrolyte, for example, by 27.8, 88.5, and 81.9% with the addition of 1%wt of EDTA disodium salt, pyrogallol, and ascorbic acid, respectively. The cell cycling also indicated the effect of organic additives on the cell performance, with significant reduction in the usable charge capacity. In addition, a standard screening method for thermally stable additives was introduced, to quickly screen suitable additives for the positive vanadium electrolyte.

Sulfuric acid dissolution of the Chashma-Sang deposit's green clays

International Nuclear Information System (INIS)

Mirzoev, D.Kh.; Boboev, Kh.E.; Pulatov, M.S.; Mirsaidov, U.M.

2005-01-01

Present article is presenting the results of the roentgen phase, thermodynamic and physical-chemical investigations of the green clays of the Chashma-Sang deposit of the Republic of Tajikistan. It is presented mineralogical and chemical composition of the mineral raw materials. Kinetic of decomposition of the oxides of aluminum and iron on temperature, time and concentration of the sulfuric acid has been investigated

Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

Science.gov (United States)

Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

2016-02-01

Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

Dynamics of a Sonoluminescing Bubble in Sulfuric Acid

Science.gov (United States)

Hopkins, Stephen D.; Putterman, Seth J.; Kappus, Brian A.; Suslick, Kenneth S.; Camara, Carlos G.

2005-12-01

The spectral shape and observed sonoluminescence emission from Xe bubbles in concentrated sulfuric acid is consistent only with blackbody emission from a spherical surface that fills the bubble. The interior of the observed 7000 K blackbody must be at least 4 times hotter than the emitting surface in order that the equilibrium light-matter interaction length be smaller than the radius. Bright emission is correlated with long emission times (˜10ns), sharp thresholds, unstable translational motion, and implosions that are sufficiently weak that contributions from the van der Waals hard core are small.

Efficiency of sulfuric acid, mined gypsum, and two gypsum by-products in soil crusting prevention and sodic soil reclamation

Energy Technology Data Exchange (ETDEWEB)

Amezketa, E.; Aragues, R.; Gazol, R. [Gobierno Navarra, Pamplona (Spain). Agricultural Resources Evaluation Center

2005-06-01

We evaluated the efficiency of four amendments (sulfuric acid, mined-gypsum, and the by-products coal-gypsum and lacto-gypsum) in crusting prevention of two calcareous nonsodic and sodic soils and in sodic soil reclamation. Treatments for crust prevention consisted of surface-applied amendments at equivalent rates of 5 Mg pure-gypsum ha{sup -1}. Treatments for sodic soil reclamation consisted of surface-applied acid and soil-incorporated gypsums at rates of 1 pure-gypsum requirement. The efficiency of these amendments was evaluated by comparing the final infiltration rates (FIR) of the amended vs. the nonamended soils measured in disturbed-soil columns pounded with low-salinity irrigation water. Electrical conductivity (EC) and Na in the leachates of the sodic soil were measured. In the crusting prevention experiment, FIRs (mm h{sup -1) of the nonsodic soil were 21 (nonamended), 33 to 35 (gypsum materials), and 53 (sulfuric acid), whereas those for the sodic soil were 0 (nonamended), 9 (lacto-gypsum), 15 to 17 (coal- and mined-gypsum), and 21 (sulfuric acid). In the sodic-soil reclamation experiment, FIRs were 0 (nonamended), 8 to 9 (gypsum-materials), and 17 (sulfuric acid) mm h{sup -1}. All amendments were effective in crusting prevention and soil reclamation, but sulfuric acid was the most efficient due to the fastest EC and Na reductions in the leachates. The three gypsum-materials were equally effective in the reclamation process and in the nonsodic soil crusting-prevention, whereas lacto-gypsum was less efficient in the sodic-soil crusting-prevention.

Methyl phosphate formation as a major degradation mode of direct methanol fuel cells with phosphoric acid based electrolytes

DEFF Research Database (Denmark)

Aili, David; Vassiliev, Anton; Jensen, Jens Oluf

2015-01-01

Phosphoric acid and phosphoric acid doped polymer membranes are widely used as electrolytes in hydrogen based fuel cells operating at elevated temperatures. Such electrolytes have been explored for direct oxidation of methanol to further increase the versatility of the systems, however......, with demonstrated lifetimes of only a few days to weeks. In this work the methyl phosphate formation from the acid and methanol is identified and proposed to be a major mechanism for the cell degradation. Proton conductivity and fuel cell durability tests validate the mechanism at high methanol contents....

Effects of acid rain and sulfur dioxide on marble dissolution

Science.gov (United States)

Schuster, Paul F.; Reddy, Michael M.; Sherwood, Susan I.

1994-01-01

Acid precipitation and the dry deposition of sulfur dioxide (SO2) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO2 gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

Sodium lauryl sulfate - a biocide for controlling acidity development in bulk commercially formed solid elemental sulfur

Energy Technology Data Exchange (ETDEWEB)

Hyne, J. B. [Calgary Univ., AB (Canada). Dept. of Biological Sciences

1996-04-01

Acidification of bulk elemental sulfur caused by Thiobacillus species which consume elemental sulfur by converting it into oxidized sulfur forms, was studied. Contributory factors, such as length of time in transit or in storage, warm temperatures, the presence of air and moisture, particle size and form of sulfur, and the presence of sources of carbon, nitrogen and phosphorus nutrients, were reviewed. Laboratory experiments with adding sodium lauryl sulfate (SLS), a known biocide, to sulfur inoculated with Thiobacillus, proved to be an efficient method for controlling acidity development. At the concentration required for effectiveness SLS did not interfere with purity specifications, had negligible effect on moisture, and appeared to be compatible with current dust suppression application practices. 2 tabs., 3 figs.

Proton-conducting solid acid electrolytes based upon MH(PO3H)

NARCIS (Netherlands)

Zhou, W.

2011-01-01

Solid acids, such as CsHSO4 and CsH2PO4, are a novel class of anhydrous proton-conducting compounds that can be used as electrolyte in H2/O2 and direct methanol fuel cells. The disordering of the hydrogen-bonded network above the so-called superprotonic phase transition results in an increase of the

Corrosion of Selected Materials in Boiling Sulfuric Acid for the Nuclear Power Industries

International Nuclear Information System (INIS)

Kim, Dong Jin; Lee, Han Hee; Kwon, Hyuk Chul; Kim, Hong Pyo; Hwang, Seong Sik

2007-01-01

Iodine sulfur (IS) process is one of the promising processes for a hydrogen production by using a high temperature heat generated by a very high temperature gas cooled reactor(VHTR) in the nuclear power industries. Even though the IS process is very efficient for a hydrogen production and it is not accompanied by a carbon dioxide evolution, the highly corrosive environment of the process limits its application in the industry. Corrosion tests of selected materials were performed in sulfuric acid to select appropriate materials compatible with the IS process. The materials used in this work were Fe-Cr alloys, Fe-Ni-Cr alloys, Fe-Si alloys, Ni base alloys, Ta, Ti, Zr, SiC, Fe-Si, etc. The test environments were 50 wt% sulfuric acid at 120 .deg. C and 98 wt% at 320 .deg. C. Corrosion rates were measured by using a weight change after an immersion. The surface morphologies and cross sectional areas of the corroded materials were examined by using SEM equipped with EDS. Corrosion behaviors of the materials were discussed in terms of the chemical composition of the materials, a weight loss, the corrosion morphology, the precipitates in the microstructure and the surface layer composition

Theoretical study of ultraviolet induced photodissociation dynamics of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Murakami, Tatsuhiro; Ohta, Ayumi; Suzuki, Tomoya; Ikeda, Kumiko [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554 (Japan); Danielache, Sebastian O. [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554 (Japan); Earth-Life Science Institute (ELSI), Tokyo Institute of Technology (Japan); Department of Environmental Science and Techonology, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yoohama 226-8502 (Japan); Nanbu, Shinkoh, E-mail: shinkoh.nanbu@sophia.ac.jp [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-Cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

2015-05-01

Highlights: • Photodissociation dynamics of H{sub 2}SO{sub 4} at low-lying electronically excited states were investigated. • Photochemical processes were simulated by on-the-fly ab initio MD. • Sulfuric acid after the excitation to the S{sub 1} state dissociated to HSO{sub 4}(1{sup 2}A″) + H({sup 2}S). • Sulfuric acid after the excitation to the S{sub 2} state dissociated to HSO{sub 4}(2{sup 2}A″) + H({sup 2}S). • The energy region of the UV spectra where NMD fractionation may occur is predicted. - Abstract: Photodissociation dynamics of sulfuric acid after excitation to the first and second excited states (S{sub 1} and S{sub 2}) were studied by an on-the-fly ab initio molecular dynamics simulations based on the Zhu–Nakamura version of the trajectory surface hopping (ZN-TSH). Forces acting on the nuclear motion were computed on-the-fly by CASSCF method with Dunning’s augmented cc-pVDZ basis set. It was newly found that the parent molecule dissociated into two reaction-channels (i) HSO{sub 4}(1{sup 2}A″) + H({sup 2}S) by S{sub 1}-excitation, and (ii) HSO{sub 4}(2{sup 2}A″) + H({sup 2}S) by S{sub 2}-excitation. The direct dissociation dynamics yield products different from the SO{sub 2} + 2OH fragments often presented in the literature. Both channels result in the same product and differs only in the electronic state of the HSO{sub 4} fragment{sub .} The trajectories running on S{sub 2} do not hop with S{sub 0} and a nonadiabatic transition happens at the S{sub 2}–S{sub 1} conical intersection located at a longer OH bond-length than the S{sub 1}–S{sub 0} intersection producing an electronic excited state (2{sup 2}A″) of HSO{sub 4} product.

Modelling the effect of temperature and free acid, silver, copper and lead concentrations on silver electrorefining electrolyte conductivity

OpenAIRE

Aji, Arif T.; Kalliomäki, Taina; Wilson, Benjamin P.; Aromaa, Jari; Lundström, Mari

2016-01-01

Conductivity is one of the key physico-chemical properties of electrolyte in silver electrorefining since it affects the energy consumption of the process. As electrorefining process development trends towards high current density operation, having electrolytes with high conductivities will greatly reduce the energy consumption of the process. This study outlines investigations into silver electrorefining electrolyte conductivity as a function of silver, free acid, copper and lead concentrati...

Liquid-liquid extraction of chromium (VI) from sulfuric acid solutions using tri-n-dodecylamine/kerosene

International Nuclear Information System (INIS)

Stas, J.

2008-01-01

Extraction of chromium (VI) from sulfuric acid solutions with tri-n-dodecylamine containing octanol-1 as a modifier in kerosene was investigated. All parameters influencing the extraction of chromium (VI) (time of agitation, concentrations of chromium (VI), sulfuric acid, tri-n-dodecylamine and temperature) were studied. Forst of all, tri-n-dodecylamine reacts with sulfuric acid to form tri-n-dodecylamine sulfate and bisulfate salts, then, dichromate ions is extracted by amine bisulfate. The mathematical treatment of the obtained date enabled us to calculate the formation of equilibrium constant of (TDAH) 2 SO 4 TDAHHSO 4 and (TDAH) 2 Cγ 2 O 7 at 25 Centigrade and have been found to be K 1 =10 9.642 (14/mol 4 ), K 2 = 10 -0.899 (L/mol) and K ex 10 10.55 respectively. Stripping of more than 99% of chromium (VI) from the organic phase of tri-n-dodecylamine/kerosene can be easily achieved in two stages using 0.05 M sodium carbonate solution. The synergistic effect of tri-n-butylphosphate and tri-n-octylphosphine oxide on the extraction of chromium (VI) were also studied. (author)

Lowering the platinum loading of high temperature polymer electrolyte membrane fuel cells with acid doped polybenzimidazole membranes

DEFF Research Database (Denmark)

Fernandez, Santiago Martin; Li, Qingfeng; Jensen, Jens Oluf

2015-01-01

Membrane electrode assemblies (MEAs) with ultra-low Pt loading electrodes were prepared for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) based on acid doped polybenzimidazole. With no electrode binders or ionomers, the triple phase boundary of the catalyst layer was establ......Membrane electrode assemblies (MEAs) with ultra-low Pt loading electrodes were prepared for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) based on acid doped polybenzimidazole. With no electrode binders or ionomers, the triple phase boundary of the catalyst layer...

Experimental and Kinetic Modeling Studies on the Conversion of Sucrose to Levulinic Acid and 5-Hydroxymethylfurfural Using Sulfuric Acid in Water

NARCIS (Netherlands)

Tan-Soetedjo, Jenny N. M.; van de Bovenkamp, Henk H.; Abdilla, Ria M.; Rasrendra, Carolus B.; van Ginkel, Jacob; Heeres, Hero J.

2017-01-01

We here report experimental and kinetic modeling studies on the conversion of sucrose to levulinic acid (LA) and 5-hydroxymethylfurfural (HMF) in water using sulfuric acid as the catalyst. Both compounds are versatile building blocks for the synthesis of various biobased (bulk) chemicals. A total of

Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

Science.gov (United States)

Deng, Bo; Yu, Yang; Zhang, Bowu; Yang, Xuanxuan; Li, Linfan; Yu, Ming; Li, Jingye

2011-02-01

Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Deng Bo [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China); Yu Yang; Zhang Bowu; Yang Xuanxuan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China); Graduate University of Chinese Academy of Sciences, No. 19, Yuquan Road, Shijingshan Dist., 100049 Beijing (China); Li Linfan; Yu Ming [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China); Li Jingye, E-mail: jingyeli@sinap.ac.c [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 2019, Jialuo Road, Jiading Dist., 201800 Shanghai (China)

2011-02-15

Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

Graft polymerization of acrylic acid and methacrylic acid onto poly(vinylidene fluoride) powder in presence of metallic salt and sulfuric acid

International Nuclear Information System (INIS)

Deng Bo; Yu Yang; Zhang Bowu; Yang Xuanxuan; Li Linfan; Yu Ming; Li Jingye

2011-01-01

Poly(vinylidene fluoride) (PVDF) powder was grafted with acrylic acid (AAc) or methacrylic acid (MAA) by the pre-irradiation induced graft polymerization technique. The presence of graft chains was proven by FT-IR spectroscopy. The degree of grafting (DG) was calculated by the acid-base back titration method. The synergistic effect of acid and Mohr's salt on the grafting kinetics was examined. The results indicated that adding sulfuric acid and Mohr's salt simultaneously in AAc or MAA solutions led to a strong enhancement in the degree of grafting. The grafted PVDF powder was cast into microfiltration (MF) membranes using the phase inversion method and some properties of the obtained MF membranes were characterized.

Sulfur amino acids and alanine on pyrite (100) by X-ray photoemission spectroscopy: Surface or molecular role?

Science.gov (United States)

Sanchez-Arenillas, M.; Galvez-Martinez, S.; Mateo-Marti, E.

2017-08-01

This paper describes the first successful adsorption of the cysteine, cystine, methionine and alanine amino acids on the pyrite (100) surface under ultra-high vacuum conditions with crucial chemical adsorption parameters driving the process. We have demonstrated by X-ray photoemission spectroscopy (XPS) that the surface pretreatment annealing process on pyrite surfaces is a critical parameter driving surface reactivity. The presence of enriched monosulfide species on the pyrite (100) surface favours the amino acid NH2 chemical form, whereas a longer annealing surface pretreatment of over 3 h repairs the sulfur vacancies in the pyrite, enriching disulfide species on the pyrite surface, which promotes NH3+ adsorption due to the sulfur vacancies in the pyrite being replaced by sulfur atom dimers (S22-) on the surface. Furthermore, even if the surface chemistry (monosulfide or disulfide species enrichment) is the main factor promoting a partial conversion from NH2 to NH3+ species, the unique chemical structure of each amino acid provides a particular fingerprint in the process.

Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

Energy Technology Data Exchange (ETDEWEB)

Dong, Kang [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Zhang, Hanyu; Wu, Jinping [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China)

2013-06-01

Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

Combination of acid-resistor and -scavenger improves the SEI stability and cycling ability of tin–nickel battery anodes in LiPF6-containing electrolyte

International Nuclear Information System (INIS)

Choo, Myeong-Ho; Nguyen, Cao Cuong; Hong, Sukhyun; Kwon, Yo Han; Woo, Sang-Wook; Kim, Je Young; Song, Seung-Wan

2013-01-01

Control of electrode–electrolyte interfacial reactivity and the formation of the solid electrolyte interphase (SEI) layer is a key technology for high performance rechargeable lithium batteries. Here we present the first report on a promising interfacial approach for Sn–Ni electrode that the use of acid-resisting and -scavenging fluorine-dopant on Sn combined with acid-scavenging trimethyl phosphite electrolyte additive to LiPF 6 -contiaing carbonate-based organic electrolyte improves the interfacial stability of Sn to acidic electrolyte species. As a result, a stable SEI layer consisting of a plenty of carbonate decomposition products forms and cycling ability significantly improves, in contrast to less efficient SEI formation and rapid performance fade for the electrodes without fluorine-dopant or trimethyl phosphite additive

Dissolution mechanism of aluminum hydroxides in acid media

Science.gov (United States)

Lainer, Yu. A.; Gorichev, I. G.; Tuzhilin, A. S.; Gololobova, E. G.

2008-08-01

The effects of the concentration, temperature, and potential at the hydroxide/electrolyte interface on the aluminum hydroxide dissolution in sulfuric, hydrochloric, and perchloric acids are studied. The limiting stage of the aluminum hydroxide dissolution in the acids is found to be the transition of the complexes that form on the aluminum hydroxide surface from the solid phase into the solution. The results of the calculation of the acid-base equilibrium constants at the oxide (hydroxide)/solution interface using the experimental data on the potentiometric titration of Al2O3 and AlOOH suspensions are analyzed. A mechanism is proposed for the dissolution of aluminum hydroxides in acid media.

Methanesulfonic acid-assisted synthesis of N/S co-doped hierarchically porous carbon for high performance supercapacitors

Science.gov (United States)

Huo, Silu; Liu, Mingquan; Wu, Linlin; Liu, Mingjie; Xu, Min; Ni, Wei; Yan, Yi-Ming

2018-05-01

Nitrogen and sulfur co-doped carbons are considered as electrode materials for high performance supercapacitors, while their further development is still limited by complicated synthesis procedure, unsatisfied structure and low energy density. Developing a simple synthetic strategy to obtain rationally structured carbon materials and high supercapacitor performance is remaining a grand challenge. Herein, we describe the synthesis of nitrogen and sulfur co-doped hierarchical porous carbons as high performance supercapacitors electrode by a methanesulfonic acid-assisted one-step carbonization and activation of the freeze-dried precursors mixture. The as-prepared carbon material not only exhibits ideally hierarchical pores, but also realizes uniform nitrogen and sulfur co-doping. In 6.0 M KOH electrolyte, the material can achieve a high specific capacitance of 272 F g-1 at 1.0 A g-1 and a promising rate performance retaining 172 F g-1 even at 100 A g-1. Moreover, a fabricated symmetric supercapacitor based on as-prepared nitrogen and sulfur co-doped hierarchical porous carbon delivers high energy densities of 12.4 W h kg-1 and 8.0 W h kg-1 in 6.0 M KOH liquid and KOH/PVA solid-state electrolytes, respectively. This work presents a simple and effective methanesulfonic acid-assisted approach for mass production of heteroatomic doping hierarchical porous carbons for future energy storage applications.

Characterization of sulfur-oxidizing bacteria isolated from acid mine drainage and black shale samples

International Nuclear Information System (INIS)

Sajjad, W.; Bhatti, T. M.; Hasan, F.; Khan, S.; Badshah, M.

2016-01-01

Acid mine drainage (AMD) and black shale (BS) are the main habitats of sulfur-oxidizing bacteria. The aim of this study was to isolate and characterize sulfur-oxidizing bacteria from extreme acidic habitats (AMD and BS). Concentration of metals in samples from AMD and BS varied significantly from the reference samples and exceeded the acceptable limits set by the Environmental Protection Agency (EPA) and the World Health Organization (WHO). A total of 24 bacteria were isolated from these samples that were characterized both morphologically as well as through biochemical tests. All the bacteria were gram-negative rods that could efficiently oxidize sulfur into sulfate ions (SO/sub 4/-2), resulted into decrease in pH up to 1.0 when grown in thiosulfate medium with initial pH 4.0. Out of 24, only 06 isolates were selected for phylogenetic analysis through 16S rRNA sequencing, on the basis of maximum sulfur-oxidizing efficiency. The isolates were identified as the species from different genera such as Alcaligenes, Pseudomonas, Bordetella, and Stenotrophomonas on the basis of maximum similarity index. The concentration of sulfate ions produced was estimated in the range of 179-272 mg/L. These acidophiles might have various potential applications such as biological leaching of metals from low-grade ores, alkali soil reclamation and to minimize the use of chemical S-fertilizers and minimize environmental pollution. (author)

Enabling electrolyte compositions for columnar silicon anodes in high energy secondary batteries

Science.gov (United States)

Piwko, Markus; Thieme, Sören; Weller, Christine; Althues, Holger; Kaskel, Stefan

2017-09-01

Columnar silicon structures are proven as high performance anodes for high energy batteries paired with low (sulfur) or high (nickel-cobalt-aluminum oxide, NCA) voltage cathodes. The introduction of a fluorinated ether/sulfolane solvent mixture drastically improves the capacity retention for both battery types due to an improved solid electrolyte interface (SEI) on the surface of the silicon electrode which reduces irreversible reactions normally causing lithium loss and rapid capacity fading. For the lithium silicide/sulfur battery cycling stability is significantly improved as compared to a frequently used reference electrolyte (DME/DOL) reaching a constant coulombic efficiency (CE) as high as 98%. For the silicon/NCA battery with higher voltage, the addition of only small amounts of fluoroethylene carbonate (FEC) to the novel electrolyte leads to a stable capacity over at least 50 cycles and a CE as high as 99.9%. A high volumetric energy density close to 1000 Wh l-1 was achieved with the new electrolyte taking all inactive components of the stack into account for the estimation.

Numerical Simulation of Condensation of Sulfuric Acid and Water in a Large Two-stroke Marine Diesel Engine

DEFF Research Database (Denmark)

Walther, Jens Honore; Karvounis, Nikolas; Pang, Kar Mun

2016-01-01

We present results from computational fluid dynamics simulations of the condensation of sulfuric acid (H2SO4) and water (H2O) in a large two-stroke marine diesel engine. The model uses a reduced n-heptane skeletal chemical mechanism coupled with a sulfur subsetto simulate the combustion process...

POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

DEFF Research Database (Denmark)

2001-01-01

A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes....... With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid...

Anode Improvement in Rechargeable Lithium-Sulfur Batteries.

Science.gov (United States)

Tao, Tao; Lu, Shengguo; Fan, Ye; Lei, Weiwei; Huang, Shaoming; Chen, Ying

2017-12-01

Owing to their theoretical energy density of 2600 Wh kg -1 , lithium-sulfur batteries represent a promising future energy storage device to power electric vehicles. However, the practical applications of lithium-sulfur batteries suffer from poor cycle life and low Coulombic efficiency, which is attributed, in part, to the polysulfide shuttle and Li dendrite formation. Suppressing Li dendrite growth, blocking the unfavorable reaction between soluble polysulfides and Li, and improving the safety of Li-S batteries have become very important for the development of high-performance lithium sulfur batteries. A comprehensive review of various strategies is presented for enhancing the stability of the anode of lithium sulfur batteries, including inserting an interlayer, modifying the separator and electrolytes, employing artificial protection layers, and alternative anodes to replace the Li metal anode. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Corrosion-electrochemical characteristics of oxide-carbide and oxide-nitride coatings formed by electrolytic plasma

International Nuclear Information System (INIS)

Tomashov, N.D.; Chukalovskaya, T.V.; Medova, I.L.; Duradzhi, V.N.; Plavnik, G.M.

1990-01-01

The composition, structure, microhardness and corrosion-electrochemical properties of oxide-carbide and oxide-nitride coatings on titanium in 5n H 2 SO 4 , 50 deg, produced by the method of chemical-heat treatment in electrolytic plasma, containing saturation components of nitrogen and carbon, were investigated. It is shown that the coatings produced have increased hardness, possess high corrosion resistance in sulfuric acid solution at increased temperature, as to their electrochemcial behaviour they are similar to titanium carbide and nitride respectively. It is shown that high corrosion resistance is ensured by electrochemical mechanism of the oxide-carbide and oxide-nitride coating protection

Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

International Nuclear Information System (INIS)

Ma Yongjun; Jin Xiaoyong; Zhou Min; Zhang Ziyu; Teng Xiulan; Chen Hui

2003-01-01

The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l -1 and cerium sulfate was 1.6 mmol l -1 in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l -1 sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm

Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

Energy Technology Data Exchange (ETDEWEB)

Ma Yongjun; Jin Xiaoyong; Zhou Min; Zhang Ziyu; Teng Xiulan; Chen Hui

2003-08-18

The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l{sup -1} and cerium sulfate was 1.6 mmol l{sup -1} in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l{sup -1} sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm.

Electrocatalysis of fuel cell reactions: Investigation of alternate electrolytes

Science.gov (United States)

Chin, D. T.; Hsueh, K. L.; Chang, H. H.

1984-01-01

Oxygen reduction and transport properties of the electrolyte in the phosphoric acid fuel cell are studied. The areas covered were: (1) development of a theoretical expression for the rotating ring disk electrode technique; (2) determination of the intermediate reaction rate constants for oxygen reduction on platinum in phosphoric acid electrolyte; (3) determination of oxygen reduction mechanism in trifluoreomethanesulfonic acid (TFMSA) which was considered as an alternate electrolyte for the acid fuel cells; and (4) the measurement of transport properties of the phosphoric acid electrolyte at high concentrations and temperatures.

Effect of sulphuric acid concentration on electroosmotic flow through polymer electrolyte membranes in PEM fuel cells. Paper no. IGEC-1-061

International Nuclear Information System (INIS)

Karimi, G.; Li, X.

2005-01-01

Polymer electrolyte membrane (PEM) fuel cells are highly efficient and environmentally clean, and hence one of the most promising power sources for both stationary and mobile applications. The operations of PEM fuel cells are complicated by the electroosmotic flow of water from anode to cathode through the polymer electrolyte membrane leading to the membrane dehydration and fuel cell performance degradations. In this study, electro osmotic flow in polymer electrolyte membranes is modeled by incorporating the electro kinetic effects in the presence of euphoric acid. The governing Poisson-Boatman and the Nervier-Stokes equations were solved numerically for a single membrane pore to determine the electro osmotic flow distributions through the membrane over a wide range of acid concentrations. The presence of euphoric acid modifies the protons distribution in the membrane and hence alters the driving force for electroosmotic drag. Numerical results indicate that the electro osmotic flow increases steadily with acid concentration. The water transport due to electro osmosis is almost doubled at 2 M acid concentration compared with that of non-doped membrane. The value of electroosmotic drag coefficient however falls steadily with acid concentration due to the presence of a larger number of protons in the electrolyte. (author)

A hydrogen production experiment by the thermo-chemical and electrolytic hybrid hydrogen production in lower temperature range. System viability and preliminary thermal efficiency estimation

International Nuclear Information System (INIS)

Takai, Toshihide; Nakagiri, Toshio; Inagaki, Yoshiyuki

2008-10-01

A new experimental apparatus by the thermo-chemical and electrolytic Hybrid-Hydrogen production in Lower Temperature range (HHLT) was developed and hydrogen production experiment was performed to confirm the system operability. Hydrogen production efficiency was estimated and technical problems were clarified through the experimental results. Stable operation of the SO 3 electrolysis cell and the sulfur dioxide solution electrolysis cell were confirmed during experimental operation and any damage which would be affected solid operation was not detected under post operation inspection. To improve hydrogen production efficiency, it was found that the reduction of sulfuric acid circulation and the decrease in the cell voltage were key issues. (author)

Materials development for thermochemical cycles: sulfuric acid vaporizer. Semiannual technical report, October 1, 1977--March 31, 1978

International Nuclear Information System (INIS)

Krikorian, O.H.

1978-01-01

Installation of a sulfuric acid corrosion test facility has been completed and is described. The facility is to be used for testing of potential materials for containment and heat exchange of a sulfuric acid vaporizer at temperatures up to 725 0 K and boiling pressures of >20 atm (2 MPa). Materials that are ready for test are Duriron, Durichlor 51, single crystal Si, hot-pressed Si 3 N 4 (Noralide NC-132), and hot-pressed SiC (Crystar HD-435), and tests are expected to get underway in April pending Hazards Control approval

Effect of L-glutamic acid on the positive electrolyte for all-vanadium redox flow battery

International Nuclear Information System (INIS)

Liang, Xinxing; Peng, Sui; Lei, Ying; Gao, Chao; Wang, Nanfang; Liu, Suqin; Fang, Dong

2013-01-01

Highlights: ► Amino acid is used as additive for all-vanadium redox flow battery. ► The additive can significantly improve performance of positive electrolyte. ► Mechanism for the improvement is investigated. -- Abstract: L-Glutamic acid is used as an additive for the positive electrolyte of all-vanadium redox flow battery (VRFB), and its effect on the thermal stability and electrochemical activity is investigated. It is found that the addition of L-glutamic can significantly alleviate the precipitation of V 2 O 5 from positive electrolyte. The conservation rate of V(V) ion can be as high as 58% after 2 M V(V) solution being kept in 40 °C for 89 h. Besides, L-glutamic can also improve the mass transport and electrochemical performance of anolyte. A high coulombic efficiency of over 95% and energy efficiency of 74% are obtained. XPS spectra illustrate that L-glutamic can react with the surface of carbon felt electrode and introduce more oxygen-containing and nitrogen-containing groups, which should be responsible for the improvement of electrochemical performance

Application of in operando UV/Vis spectroscopy in lithium-sulfur batteries.

Science.gov (United States)

Patel, Manu U M; Dominko, Robert

2014-08-01

Application of UV/Vis spectroscopy for the qualitative and quantitative determination of differences in the mechanism of lithium-sulfur battery behavior is presented. With the help of catholytes prepared from chemically synthesized stoichiometric mixtures of lithium and sulfur, calibration curves for two different types of electrolyte can be constructed. First-order derivatives of UV/Vis spectra show five typical derivative peak positions in both electrolytes. In operando measurements show a smooth change in the UV/Vis spectra in the wavelength region between λ=650 and 400 nm. Derivatives are in agreement with derivative peak positions observed with catholytes. Recalculation of normalized reflections of UV/Vis spectra obtained in operando mode enable the formation of polysulfides and their concentrations to be followed. In such a way, it is possible to distinguish differences in the mechanism of polysulfide shuttling between two electrolytes and to correlate differences in capacity fading. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sulfur amino acids are necessary for normal intestinal mucosal growth in neonatal piglets

Science.gov (United States)

Sulfur amino acids (SAAs) methionine and cysteine play important metabolic and functional role in human health and disease. Gastrointestinal tract is an important site of transmethylation and transsulfuration of methionine and metabolizes approx. 20% of the dietary methionine intake (Riedijk et al. ...

Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

DEFF Research Database (Denmark)

Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

2018-01-01

Corrosive wear of cylinder liners in large two-stroke marine diesel engines that burn heavy fuel oil containing sulfur is coupled to the formation of gaseous sulfur trioxide (SO3) and subsequent combined condensation of sulfuric acid (H2SO4) and water (H2O) vapor. The present work seeks to address...... vapor liquid equilibrium. By assuming homogenous cylinder gas mixtures condensation is modeled using a convective heat and mass transfer analogy combined with realistic liner temperature profiles. Condensation of water is significantly altered by the liner temperature and charge air humidity while...... how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

Investigation of a mutual interaction force at different pressure amplitudes in sulfuric acid

International Nuclear Information System (INIS)

Rezaee, Nastaran; Sadighi-Bonabi, Rasoul; Mirheydari, Mona; Ebrahimi, Homa

2011-01-01

This paper investigates the secondary Bjerknes force for two oscillating bubbles in various pressure amplitudes in a concentration of 95% sulfuric acid. The equilibrium radii of the bubbles are assumed to be smaller than 10 μm at a frequency of 37 kHz in various strong driving acoustical fields around 2.0 bars (1 bar=10 5 Pa). The secondary Bjerknes force is investigated in uncoupled and coupled states between the bubbles, with regard to the quasi-adiabatic model for the bubble interior. It finds that the value of the secondary Bjerknes force depends on the driven pressure of sulfuric acid and its amount would be increased by liquid pressure amplitude enhancement. The results show that the repulsion area of the interaction force would be increased by increasing the driven pressure because of nonlinear oscillation of bubbles. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Electrochemical flue gas desulfurization: Reactions in a pyrosulfate-based electrolyte

International Nuclear Information System (INIS)

Scott, K.; Fannon, T.; Winnick, J.

1988-01-01

A new electrolyte has been found suitable for use in an electrochemical membrane cell for flue gas desulfurization (FGD). The electrolyte is primarily K/sub 2/S/sub 2/O/sub 7/ and K/sub 2/SO/sub 4/ with V/sub 2/O/sub 5/ as oxidation enhancer. This electrolyte has a melting point near 300/sup 0/C which is compatible with flue gas exiting the economizer of coal-burning power plants. Standard electrochemical tests have revealed high exchange current densities around 30 mA/cm/sup 2/, in the free electrolyte. Sulfur dioxide is found to be removed from simulated flue gas in a multiple-step process, the first of which is electrochemical reduction of pyrosulfate

Sulfuric acid and hot water treatments enhance ex vitro and in vitro ...

African Journals Online (AJOL)

Seeds of Hibiscus dasycalyx S. F. Blake and Shiller, a federally listed candidate endangered species and native to North America and two variants of Hibiscus acetosella Welw. ex. Hiern were scarified using sulfuric acid and hot water. The effects of the scarification methods on in vitro and ex vitro germination in both ...

DORMANCY BREAKING OF OIL PALM SEED TENERA VARIETY BY SOAKING FOR A CERTAIN LENGTH OF TIME IN THE SULFURIC ACID SOLUTION

Directory of Open Access Journals (Sweden)

WAYAN SUENA

2012-11-01

Full Text Available The experiment aimed to know the effect of length of soaked time in sulfuric acid (H2SO4 solution to the dormancy breaking upon the oil palm seeds. The experiment show that soaking seeds for 12 and 10 minutes in the acid solution resulted dormancy breaking were reached after 61.3 days, while soaking seed for 2 minutes in the same solution breaking of dormancy was reached after 73.5 days. By soaked oil palm seeds in sulfuric acid solution gave highest germination percentage (80%, peak value of germination was 0.77%/day, by an average of 0.73%/day. So that, by soaked oil palm seed in sulfuric acid solution for 12 minutes was able to increase vigor, viability, rate of germination and growth uniformity.

Liquid-Liquid extraction of sulfuric acid using tri-n-dodecylamine/kerosene

International Nuclear Information System (INIS)

Stas, J.

2009-01-01

The extraction of sulfuric acid has been investigated by trin- dodecylamine (over line TDA) in kerosene in the presence of octanol- 1 as modifier. The effect of octanol-1 has been studied on the equilibrium constant of (TDAH) 2 SO 4 and TDAHHSO 4 formation in the concentration range from 5 to 25% v/v and within the temperature range from 25 to 50 centigrade degree. The equilibrium constants (K 1 and K 2 , at 25 centigrade degree), the enthalpy (ΔH 0 1 , ΔH 0 2 ) and the entropy (ΔS 0 1 , ΔS 0 2 ) changes were calculated for two extraction reactions of sulfuric acid by tri-n-dodecylamine containing 10% octanol-1 and they were found to be 10 9 .642 l 4 /mol 4 , 10 - 0.899 l/mol, -99.11, -22.17 kJ/mol, -0.149, -0.063 kJ/mol.K, respectively. The two reactions are: 2/overline TDA +2 H + +SO 4 2 -/rightleftarrows K 1 /overline (TDAH) 2 SO 4 and /overline (TDHA) 2 SO 4 H + +HSO 4 - /rightleftarrows K 2 2/overline TDAHHSO 4 . (author)

Enhanced electrocatalysis performance of amorphous electrolytic carbon from CO2 for oxygen reduction by surface modification in molten salt

International Nuclear Information System (INIS)

Chen, Zhigang; Gu, Yuxing; Du, Kaifa; Wang, Xu; Xiao, Wei; Mao, Xuhui; Wang, Dihua

2017-01-01

Highlights: •The potential of electrolytic carbon as catalyst for oxygen reduction was evaluated. •A molten salt method for electrolytic-carbon modification was demonstrated. •The electrolytic carbon was activated for the ORR by the molten salt sulfidation. •Sulfur and cobalt dual modification further improved the ORR activity of the carbon. -- Abstract: The electrolytic carbon (E-carbon) derived from greenhouse gas CO 2 in molten carbonates at mild temperature possesses high electrical conductivity and suitable specific surface area. In this work, its potential as catalyst is investigated towards oxygen reduction reaction (ORR). It is revealed that the pristine E-carbon has no electrocatalytic activity for the ORR due to its high surface content of carboxyl group. The carbon was then treated in a Li 2 SO 4 containing Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 molten salt at 550 °C. Sulfur modified E-carbon was obtained in the melt via a galvanic sulfidation reaction, in which Li 2 SO 4 served as a nontoxic sulfur source and an oxidant. The sulfur modified E-carbon showed a significantly improved electrocatalytic activity. Subsequently, a sulfur/cobalt dual modified carbon with much higher catalysis activity was successfully prepared by treating an E-carbon/CoSO 4 composite in the same melt. The dual modified E-carbon showed excellent catalytic performance with activity close to the commercial Pt/C catalyst but a high tolerance towards methanol.

Controlled-potential coulometric determination of plutonium with a hydrochloric acid-sulfamic acid electrolyte and phosphate complexing

International Nuclear Information System (INIS)

Jackson, D.D.; Hollen, R.M.; Roensch, F.R.; Rein, J.E.

1981-01-01

Total plutonium is selectively determined by a controlled-potential coulometric method in which plutonium is reduced to Pu(III) at 0.25 V (vs. SCE) in a 5.5 M hydrochloric acid-0.015 M sulfamic acid electrolyte, diverse ions are oxidized at 0.57 V, phosphate is added to reduce the Pu(III)-Pu(IV) potential, and Pu(III) is oxidized to Pu(IV) at 0.68 V. None of more than 50 metal ions present in nuclear fuel-cycle material interferes. Many anions are without effect and most interfering ones are removed by preliminary fuming with perchloric acid. The apparatus described consists mainly of commercial components. The relative standard deviation is < 0.1% at the 5-mg plutonium level

Experimental and Kinetic Modeling Studies on the Sulfuric Acid Catalyzed Conversion of D-Fructose to 5-Hydroxymethylfurfural and Levulinic Acid in Water

NARCIS (Netherlands)

Fachri, Boy A.; Abdilla, Ria M.; van de Bovenkamp, Henk H.; Rasrendra, Carolus B.; Heeres, Hero J.

2015-01-01

Levulinic acid (LA) and 5-hydroxymethylfurfural (HMF) have been identified as promising biomass-derived platform chemicals. A kinetic study on the conversion of D-fructose to HMF and LA in water using sulfuric acid as the catalyst has been performed in batch setups. The experiments were carried out

Basic principles of electrolyte chemistry for microfluidic electrokinetics. Part II: Coupling between ion mobility, electrolysis, and acid-base equilibria.

Science.gov (United States)

Persat, Alexandre; Suss, Matthew E; Santiago, Juan G

2009-09-07

We present elements of electrolyte dynamics and electrochemistry relevant to microfluidic electrokinetics experiments. In Part I of this two-paper series, we presented a review and introduction to the fundamentals of acid-base chemistry. Here, we first summarize the coupling between acid-base equilibrium chemistry and electrophoretic mobilities of electrolytes, at both infinite and finite dilution. We then discuss the effects of electrode reactions on microfluidic electrokinetic experiments and derive a model for pH changes in microchip reservoirs during typical direct-current electrokinetic experiments. We present a model for the potential drop in typical microchip electrophoresis device. The latter includes finite element simulation to estimate the relative effects of channel and reservoir dimensions. Finally, we summarize effects of electrode and electrolyte characteristics on potential drop in microfluidic devices. As a whole, the discussions highlight the importance of the coupling between electromigration and electrophoresis, acid-base equilibria, and electrochemical reactions.

Concentration of sulfur-containing amino acids at turkey broilers during and after muscle dystrophy, fed with deficient feed supplemented with oxidised fat

Directory of Open Access Journals (Sweden)

K. Stoyanchev

2017-06-01

Full Text Available Abstract. The aim of the present study was to reproduce experimentally muscular dystrophy in 50 broiler turkeys, through early nutrition with a diet deficient in vitamin E, selenium and sulfur-containing amino acids, supplemented with oxidised fat and to study blood plasma sulfur containing amino acids (methionine rd and cysteine. The experiments were conducted with 1 day-old broiler turkeys. By the 3 day of life, they were divided into 40 experimental (II group and 10 control birds (I group; the latter were fed a standard compound feed, whereas the former group received a diet deficient in sulfur-containing amino acids methionine and cysteine (reduced up to 50%, vitamin E, and Se (from 0.2 mg/kg in standard feed to 0.01 mg/kg, further supplemented with oxidized fat containing peroxides and aldehydes with peroxide number of the food 8.0 meq O /kg. The clinical signs of experimental muscle dystrophy in broiler turkeys 2 th appeared first by the 25 day of feeding, when the mild clinical form (II A group and the severe clinical form (II B group werewas established. The results indicated clearly that in turkey broilers suffering from muscle dystrophy, the concentrations of sulfur-containing amino acids cysteine and methionine decreased. After the treatment of turkey broilers withmuscle dystrophy, and supplementation with non-deficient forage with Se, vitamin E, but also with sulfurcontaining amino acids cysteine ormethionine with Seled at a dosage 0.06mg/kg, the plasma levels of sulfur-containing amino acids cysteine andmethionine ® was normalized in the mild clinical form (II A group. The birds affected by the severe clinical form of disease (II B group, which were not treated with Seled and whose deficient feed was not corrected, could not recover and levels of sulfur-containing amino acids cysteine and methionine did not normalize.

Leaching and recovery of zinc and copper from brass slag by sulfuric acid

OpenAIRE

Ahmed, I.M.; Nayl, A.A.; Daoud, J.A.

2016-01-01

Leaching and recovery processes for zinc and copper from brass slag by sulfuric acid were carried out and iron and aluminum were also precipitated as hydroxides in addition to silica gel. The factors affecting the performance and efficiency of the leaching processsuch as agitation rate, leaching time, acid concentration and temperature were separately investigated. The results obtained revealed that zinc and copper are successfully recovered from these secondary resources, where the percent r...

Alkoxide-based magnesium electrolyte compositions for magnesium batteries

Science.gov (United States)

Dai, Sheng; Sun, Xiao-Guang; Liao, Chen; Guo, Bingkun

2018-01-30

Alkoxide magnesium halide compounds having the formula: RO--Mg--X (1) wherein R is a saturated or unsaturated hydrocarbon group that is unsubstituted, or alternatively, substituted with one or more heteroatom linkers and/or one or more heteroatom-containing groups comprising at least one heteroatom selected from fluorine, nitrogen, oxygen, sulfur, and silicon; and X is a halide atom. Also described are electrolyte compositions containing a compound of Formula (1) in a suitable polar aprotic or ionic solvent, as well as magnesium batteries in which such electrolytes are incorporated.

Molecular understanding of atmospheric particle formation from sulfuric acid and large oxidized organic molecules

CERN Document Server

Schobesberger, Siegfried; Bianchi, Federico; Lönn, Gustaf; Ehn, Mikael; Lehtipalo, Katrianne; Dommen, Josef; Ehrhart, Sebastian; Ortega, Ismael K; Franchin, Alessandro; Nieminen, Tuomo; Riccobono, Francesco; Hutterli, Manuel; Duplissy, Jonathan; Almeida, João; Amorim, Antonio; Breitenlechner, Martin; Downard, Andrew J; Dunne, Eimear M; Flagan, Richard C; Kajos, Maija; Keskinen, Helmi; Kirkby, Jasper; Kupc, Agnieszka; Kürten, Andreas; Kurtén, Theo; Laaksonen, Ari; Mathot, Serge; Onnela, Antti; Praplan, Arnaud P; Rondo, Linda; Santos, Filipe D; Schallhart, Simon; Schnitzhofer, Ralf; Sipilä, Mikko; Tomé, António; Tsagkogeorgas, Georgios; Vehkamäki, Hanna; Wimmer, Daniela; Baltensperger, Urs; Carslaw, Kenneth S; Curtius, Joachim; Hansel, Armin; Petäjä, Tuukka; Kulmala, Markku; Donahue, Neil M; Worsnop, Douglas R

2013-01-01

Atmospheric aerosols formed by nucleation of vapors affect radiative forcing and therefore climate. However, the underlying mechanisms of nucleation remain unclear, particularly the involvement of organic compounds. Here, we present high-resolution mass spectra of ion clusters observed during new particle formation experiments performed at the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research. The experiments involved sulfuric acid vapor and different stabilizing species, including ammonia and dimethylamine, as well as oxidation products of pinanediol, a surrogate for organic vapors formed from monoterpenes. A striking resemblance is revealed between the mass spectra from the chamber experiments with oxidized organics and ambient data obtained during new particle formation events at the Hyytiälä boreal forest research station. We observe that large oxidized organic compounds, arising from the oxidation of monoterpenes, cluster directly with single sulfuric acid molec...

Structural analysis and taste evaluation of γ-glutamyl peptides comprising sulfur-containing amino acids.

Science.gov (United States)

Amino, Yusuke; Wakabayashi, Hidehiko; Akashi, Satoko; Ishiwatari, Yutaka

2018-03-01

The structures, flavor-modifying effects, and CaSR activities of γ-glutamyl peptides comprising sulfur-containing amino acids were investigated. The chemical structures, including the linkage mode of the N-terminal glutamic acid, of γ-L-glutamyl-S-(2-propenyl)-L-cysteine (γ-L-glutamyl-S-allyl-L-cysteine) and its sulfoxide isolated from garlic were established by comparing their NMR spectra with those of authentic peptides prepared using chemical methods. Mass spectrometric analysis also enabled determination of the linkage modes in the glutamyl dipeptides by their characteristic fragmentation. In sensory evaluation, these peptides exhibited flavor-modifying effects (continuity) in umami solutions less pronounced but similar to that of glutathione. Furthermore, the peptides exhibited intrinsic flavor due to the sulfur-containing structure, which may be partially responsible for their flavor-modifying effects. In CaSR assays, γ-L-glutamyl-S-methyl-L-cysteinylglycine was most active, which indicates that the presence of a medium-sized aliphatic substituent at the second amino acid residue in γ-glutamyl peptides enhances CaSR activity.

Bio-electrolytic sensor for rapid monitoring of volatile fatty acids in anaerobic digestion process

DEFF Research Database (Denmark)

Jin, Xiangdan; Li, Xiaohu; Zhao, Nannan

2017-01-01

This study presents an innovative biosensor that was developed on the basis of a microbial electrolysis cell for fast and reliable measurement of volatile fatty acids (VFA) during anaerobic digestion (AD) process. The bio-electrolytic sensor was first tested with synthetic wastewater containing...

Basic principles of electrolyte chemistry for microfluidic electrokinetics. Part I: Acid-base equilibria and pH buffers.

Science.gov (United States)

Persat, Alexandre; Chambers, Robert D; Santiago, Juan G

2009-09-07

We review fundamental and applied acid-base equilibrium chemistry useful to microfluidic electrokinetics. We present elements of acid-base equilibrium reactions and derive rules for pH calculation for simple buffers. We also present a general formulation to calculate pH of more complex, arbitrary mixtures of electrolytes, and discuss the effects of ionic strength and temperature on pH calculation. More practically, we offer advice on buffer preparation and on buffer reporting. We also discuss "real world" buffers and likely contamination sources. In particular, we discuss the effects of atmospheric carbon dioxide on buffer systems, namely, the increase in ionic strength and acidification of typical electrokinetic device buffers. In Part II of this two-paper series, we discuss the coupling of acid-base equilibria with electrolyte dynamics and electrochemistry in typical microfluidic electrokinetic systems.

Soil degradation by sulfuric acid disposition on uranium producing sites in south Bulgaria

International Nuclear Information System (INIS)

Atanasov, I.; Gribachev, P.

1997-01-01

This study assesses the damage of soils caused by spills of sulfuric acid solutions used for in situ leaching of uranium at eight uranium producing (by open-cast method) sites (total area of approximately 220 ha) in the region of Momino-Rakovski (South Bulgaria). The upper soil layer is cinnamonic pseudopodzolic ( or Eutric Planosols by FAO Legend, 1974). The results of the investigation show that the sulfuric acid spills caused strong acidification of upper (0-20 cm) and subsurface (20-60 cm) soil horizons which is expressed as decreasing of pH (H 2 O) to 2.9-3.5 and increasing of exchangeable H + and Al 3+ to 18 and 32% from CEC. Acid degradation of soils is combined with reducing of organic matter content. The average concentration of the total heavy metal content in the upper soil horizon (in ppm) is: Cd=1.5; Cu=30; Pb=25; Zn=40 and U=8. No significant differences were detected between the upper and subsurface soil layers . The heavy metal concentration did not exceed the Bulgarian standards for heavy metals and uranium content of soils. But the coarse texture of the top soil layers, the lack of carbonates, The low CEC and strong acidity determine a low buffering capacity of the investigated soils and this can be considered as hazardous for plants. This indicates that a future soil monitoring should be carried out in the region together with measures for neutralizing of soil acidity

Synthesis of novel acid electrolytes for phosphoric acid fuel cells

Science.gov (United States)

Adcock, James L.

1988-11-01

A 40 millimole per hour scale aerosol direct fluorination reactor was constructed. F-Methyl F-4-methoxybutanoate and F-4-methoxybutanoyl fluoride were synthesized by aerosol direct fluorination of methyl 4-methoxybutanoate. Basic hydrolysis of the perfluorinated derivatives produce sodium F-4 methoxybutanoate which was pyrolyzed to F-3-methoxy-1-propene. Purification and shipment of 33 grams of F-3-methoxy-1-propene followed. Syntheses by analogous methods allowed production and shipment of 5 grams of F-3-ethoxy 1-propene, 18 grams of F-3-(2-methoxy.ethoxy) 1-propene, and 37 grams of F-3,3-dimethyl 1-butene. Eighteen grams of F-2,2-dimethyl 1-chloropropane was produced directly and shipped. As suggested by other contractors, 5 grams of F-3-methoxy 1-iodopropane, and 5 grams of F-3-(2-methoxy.ethoxy) 1-iodopropane were produced by converting the respective precursor acid sodium salts produced for olefin synthesis to the silver salts and pyrolyzing them with iodine. Each of these compounds was prepared for the first time by the aerosol fluorination process during the course of the contract. These samples were provided to other Gas Research Institute (GRI) contractors for synthesis of perfluorinated sulfur (VI) and phosphorous (V) acids.

Oxidation of SO2 by stabilized Criegee intermediate (sCI radicals as a crucial source for atmospheric sulfuric acid concentrations

Directory of Open Access Journals (Sweden)

M. Boy

2013-04-01

Full Text Available The effect of increased reaction rates of stabilized Criegee intermediates (sCIs with SO2 to produce sulfuric acid is investigated using data from two different locations, SMEAR II, Hyytiälä, Finland, and Hohenpeissenberg, Germany. Results from MALTE, a zero-dimensional model, show that using previous values for the rate coefficients of sCI + SO2, the model underestimates gas phase H2SO4 by up to a factor of two when compared to measurements. Using the rate coefficients recently calculated by Mauldin et al. (2012 increases sulfuric acid by 30–40%. Increasing the rate coefficient for formaldehyde oxide (CH2OO with SO2 according to the values recommended by Welz et al. (2012 increases the H2SO4 yield by 3–6%. Taken together, these increases lead to the conclusion that, depending on their concentrations, the reaction of stabilized Criegee intermediates with SO2 could contribute as much as 33–46% to atmospheric sulfuric acid gas phase concentrations at ground level. Using the SMEAR II data, results from SOSA, a one-dimensional model, show that the contribution from sCI reactions to sulfuric acid production is most important in the canopy, where the concentrations of organic compounds are the highest, but can have significant effects on sulfuric acid concentrations up to 100 m. The recent findings that the reaction of sCI + SO2 is much faster than previously thought together with these results show that the inclusion of this new oxidation mechanism could be crucial in regional as well as global models.

[Application of the vanillin sulfuric acid colorimetry-ultraviolet spectrometry on quality evaluation of Panax notoginseng].

Science.gov (United States)

Ding, Yong-Li; Wang, Yuan-Zhong; Zhang, Ji; Zhang, Qing-Zhi; Zhang, Jin-Yu; Jin, Hang

2013-02-01

In this study, Panax notoginseng samples were extracted by chloroform, ethanol and water, or by those extracted solution with 5% vanillin sulfuric acid to establish two kinds of UV fingerprint of P. notoginseng which were compared by applying the common and variation peak ratio dual index sequence analysis method and SIMCA software qualitative analysis. The results indicated that the optimization extraction time of P. notoginseng samples was 20 min with chloroform, ethanol and water extraction, but the fingerprint differed significantly after add vanillin sulfuric acid. The common peak ratios of UV fingerprint of P. notoginseng were scattered. The minimum was 25% (Y5-Y8), while the maximum was 84.38% (Y11-Y13, Y20-Y21). The maximum variation peak ratio was 177.78% (Y8-Y5), meanwhile, the variation peak ratios of several samples were more than 100%. However, the common peak ratios of UV fingerprint of P. notoginseng with vanillin sulfuric acid were concentrated (distributed in the range of 50%-70%): the minimum was 42.86%(Y1-Y19), whereas the maximum was 79.55% (Y22-Y23); the range of the variation peak ratios was also smaller with the ranges of 20%-50% in general. The result of the dual index sequence analysis was agreement with the fingerprint implied. The similarity of the UV fingerprint of the extracts of P. notoginseng after adding vanillin sulfuric acid was greater than before. Both the ages and origin was related with the difference of UV fingerprint. The similarity of the two samples with same age was more significant than those with different ages. The similarity and difference between samples was no correlation with the distance of geographic space, the near origin samples maybe have a significant similarity or difference. This method appears as good alternative for evaluate quality of the P. notoginseng and can distinguish at least two samples quantitatively, duo to it reaches the limitation of the multiple methods which only could be used to indistinctly

Process Design Aspects for Scandium-Selective Leaching of Bauxite Residue with Sulfuric Acid

OpenAIRE

Konstantinos Hatzilyberis; Theopisti Lymperopoulou; Lamprini-Areti Tsakanika; Klaus-Michael Ochsenkühn; Paraskevas Georgiou; Nikolaos Defteraios; Fotios Tsopelas; Maria Ochsenkühn-Petropoulou

2018-01-01

Aiming at the industrial scale development of a Scandium (Sc)-selective leaching process of Bauxite Residue (BR), a set of process design aspects has been investigated. The interpretation of experimental data for Sc leaching yield, with sulfuric acid as the leaching solvent, has shown significant impact from acid feed concentration, mixing time, liquid to solids ratio (L/S), and number of cycles of leachate re-usage onto fresh BR. The thin film diffusion model, as the fundamental theory for l...

Decoupling the Impacts of Heterotrophy and Autotrophy on Sulfuric Acid Speleogenesis

Science.gov (United States)

Jones, A. A.; Bennett, P.

2013-12-01

Within caves such as Movile Caves (Romania), the Frasassi Caves (Italy), and Lower Kane Cave (LKC, Wyoming, USA) the combination of abiotic autoxidation and microbiological oxidation of H2S produces SO42- and H+ that promotes limestone dissolution through sulfuric-acid speleogenesis (SAS). Microbial sulfide oxidation by sulfur-oxidizing bacteria (SOB) has been shown recently to be the dominant process leading to speleogenesis in these caves. However, due to the inherently large diversity of microbial communities within these environments, there are a variety of metabolic pathways that can impact limestone dissolution and carbon cycling to varying degrees. In order to investigate these variations we outfitted a continuous flow bioreactor with a Picarro Wavelength-Scanned Cavity Ring Down Spectrometer (WS-CRDS) that continuously monitored and logged 12CO2 and 13CO2 at ppmv sensitivity and isotope ratios at consumed resulting in lighter CO2 in the headspace. 16S rRNA sequences confirm that heterotrophic sulfur-reducing bacteria dominate the community within this reactor. When both acetate and CO2 were supplied the heterotrophic behavior appeared to dominate the system which resulted in a significant drop (15‰) in δ13C and a correlative drop in limestone dissolution rate. These results suggest that chemoautotrophy increases the rate of SAS and CO2 flux within the cave environment while heterotrophy leads to slower SAS or even calcite precipitation. Furthermore, changes in carbon substrate (CO2 vs. Acetate) or sulfur substrate concentrations caused an immediate microbial response that could be observed in all measured chemical variables.

Recovery of vanadium (V) from used catalysts in sulfuric acid production units by oxalic acid

International Nuclear Information System (INIS)

Abdulbaki, M.; Shino, O.

2009-07-01

Vanadium penta oxide (V 2 O 5 ), is used, in large quantities as a catalyst for the oxidation of SO 2 to SO 3 in sulfuric acid production units, during the oxidation process the level of the oxidation declines with the time because of catalyst poisoning. So the spent catalyst is usually through out in a specified special places by General Fertilizer Company which causes a pollution of the land. The present paper, studies the recovery of vanadium from the spent catalyst by using the oxalic acid. The optimal conditions of spent catalyst leaching have been studied. It has been shown that 2%(w/w) of oxalic acid is the most suitable for leaching process at 70 degree centigrade. The precipitation of vanadium using some alkaline media NH 4 OH has been also studied, it has been shown that ammonium hydroxide was the best at 50 degree centigrade. (author)

Development of sulfuric acid dew point corrosion resistant stainless steel for smokestacks and its ducts. Entotsu endoyo tairyusan roten fushoku stainless ko no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Sato, E.; Matsuhashi, R.; Koseki, T. (Nippon Steel Corp., Tokyo (Japan)); Ebara, R.; Nakamoto, H. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan))

1993-05-20

A new corrosion resistant steel was developed as a metal system lining material to prevent sulfuric acid dew point corrosion in smokestacks and ducts. SO3 in stack gas turns to sulfuric acid as a result of reacting with coexistent moisture in non-steady conditions during boiler actuation and shutdown when smokestack walls have low temperatures. When sulfuric acid thus generated contacts with metallic materials at temperatures lower than the sulfuric acid dew point temperature, sulfuric acid dew point corrosion occurs. During boiler steady operation, localized corrosion develops at clearance between salt deposits and the metallic materials. In order to improve the corrosion resistance, Mo, Cu and N were added in a reasonable range of amount. Entire surface corrosion resistance and local corrosion resistance were experimented in aqueous solutions simulating the smokestack environments to derive relational formulas with steel compositions. The new corrosion resistant steel met the the entire surface and local corrosion resistance requirements and was found economical. Low torsional velocity tensile and U-bend tests proved the steel satisfying the stress corrosion resistance requirement. Semi-automatic CO2 welding and shielded are welding provided good workability with no cracking, and impact strength and corrosion resistance in joints equivalent to those in the base material. 3 refs., 4 figs., 4 tabs.

Microbial contributions to coupled arsenic and sulfur cycling in the acid-sulfide hot spring Champagne Pool, New Zealand

Directory of Open Access Journals (Sweden)

Katrin eHug

2014-11-01

Full Text Available Acid-sulfide hot springs are analogs of early Earth geothermal systems where microbial metal(loid resistance likely first evolved. Arsenic is a metalloid enriched in the acid-sulfide hot spring Champagne Pool (Waiotapu, New Zealand. Arsenic speciation in Champagne Pool follows reaction paths not yet fully understood with respect to biotic contributions and coupling to biogeochemical sulfur cycling. Here we present quantitative arsenic speciation from Champagne Pool, finding arsenite dominant in the pool, rim and outflow channel (55-75% total arsenic, and dithio- and trithioarsenates ubiquitously present as 18-25% total arsenic. In the outflow channel, dimethylmonothioarsenate comprised ≤9% total arsenic, while on the outflow terrace thioarsenates were present at 55% total arsenic. We also quantified sulfide, thiosulfate, sulfate and elemental sulfur, finding sulfide and sulfate as major species in the pool and outflow terrace, respectively. Elemental sulfur reached a maximum at the terrace. Phylogenetic analysis of 16S rRNA genes from metagenomic sequencing revealed the dominance of Sulfurihydrogenibium at all sites and an increased archaeal population at the rim and outflow channel. Several phylotypes were found closely related to known sulfur- and sulfide-oxidizers, as well as sulfur- and sulfate-reducers. Bioinformatic analysis revealed genes underpinning sulfur redox transformations, consistent with sulfur speciation data, and illustrating a microbial role in sulfur-dependent transformation of arsenite to thioarsenate. Metagenomic analysis also revealed genes encoding for arsenate reductase at all sites, reflecting the ubiquity of thioarsenate and a need for microbial arsenate resistance despite anoxic conditions. Absence of the arsenite oxidase gene, aio, at all sites suggests prioritization of arsenite detoxification over coupling to energy conservation. Finally, detection of methyl arsenic in the outflow channel, in conjunction with

Estimation of energy density of Li-S batteries with liquid and solid electrolytes

Science.gov (United States)

Li, Chunmei; Zhang, Heng; Otaegui, Laida; Singh, Gurpreet; Armand, Michel; Rodriguez-Martinez, Lide M.

2016-09-01

With the exponential growth of technology in mobile devices and the rapid expansion of electric vehicles into the market, it appears that the energy density of the state-of-the-art Li-ion batteries (LIBs) cannot satisfy the practical requirements. Sulfur has been one of the best cathode material choices due to its high charge storage (1675 mAh g-1), natural abundance and easy accessibility. In this paper, calculations are performed for different cell design parameters such as the active material loading, the amount/thickness of electrolyte, the sulfur utilization, etc. to predict the energy density of Li-S cells based on liquid, polymeric and ceramic electrolytes. It demonstrates that Li-S battery is most likely to be competitive in gravimetric energy density, but not volumetric energy density, with current technology, when comparing with LIBs. Furthermore, the cells with polymer and thin ceramic electrolytes show promising potential in terms of high gravimetric energy density, especially the cells with the polymer electrolyte. This estimation study of Li-S energy density can be used as a good guidance for controlling the key design parameters in order to get desirable energy density at cell-level.

Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

Energy Technology Data Exchange (ETDEWEB)

Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

2007-07-15

The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Research and development on is process components for hydrogen production. (2) Corrosion resistance of glass lining in high temperature sulfuric acid

International Nuclear Information System (INIS)

Tanaka, Nobuyuki; Iwatsuki, Jin; Kubo, Shinji; Terada, Atsuhiko; Onuki, Kaoru

2009-01-01

Japan Atomic Energy Agency has been conducting a research and development on hydrogen production system using High Temperature Gas-Cooled Reactor. As a part of this effort, thermochemical water-splitting cycle featuring iodine- and sulfur-compounds (IS process) is under development considering its potential of large-scale economical hydrogen production. The IS process constitutes very severe environments on the materials of construction because of the corrosive nature of process chemicals, especially of the high temperature acidic solution of sulfuric acid and hydriodic acid dissolving iodine. Therefore, selection of the corrosion-resistant materials and development of the components has been studied as a crucial subject of the process development. This paper discusses corrosion resistance of commercially available glass-lining material in high temperature sulfuric acid. Corrosion resistance of a soda glass used for glass-lining was examined by immersion tests. The experiments were performed in 47-90wt% sulfuric acids at temperatures of up to 400degC and for the maximum immersion time of 100 hours using an autoclave designed for the concerned tests. In every condition tested, no indication of localized corrosion such as defect formation or pitting corrosion was observed. Also, the corrosion rates decreased with the progress of immersion, and were low enough (≅0.1 mm/year) after 60-90 hours of immersion probably due to formation of a silica rich surface. (author)

Mechanism of alkylation of isobutane by olefins in the presence of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Baiburskii, V.L.; Khadzhiev, S.N.; Ovsyannikov, V.P.

1992-05-10

The authors attempted here to examine the mechanism of alkylation of isobutane by olefins in the presence of sulfuric acid in terms of an initial stage of activation of isoparaffin. The version of formation of tert-alkyl cations and the role of the catalyst in this stage were analyzed. 10 refs., 1 fig., 1 tab.

Modelling transport-limited discharge capacity of lithium-sulfur cells

International Nuclear Information System (INIS)

Zhang, Teng; Marinescu, Monica; Walus, Sylwia; Offer, Gregory J.

2016-01-01

Highlights: • We modelled the rate capability of a Li-S cell based on mass-transport limitation • The model predicts a discharged Li-S cell to regain capacity upon short relaxation • Modelled rate capability and capacity recovery effect validated with measurements - Abstract: Lithium-sulfur (Li-S) battery could bring a step-change in battery technology with a potential specific energy density of 500 - 600 Wh/kg. A key challenge for further improving the specific energy-density of Li-S cells is to understand the mechanisms behind reduced sulfur utilisation at low electrolyte loadings and high discharge currents. While several Li-S models have been developed to explore the discharge mechanisms of Li-S cells, they so far fail to capture the discharge profiles at high currents. In this study, we propose that the slow ionic transport in concentrated electrolyte is limiting the rate capability of Li-S cells. This transport-limitation mechanism is demonstrated through a one-dimensional Li-S model which qualitatively captures the discharge capacities of a sulfolane-based Li-S cell at different currents. Furthermore, our model predicts that a discharged Li-S cell is able regain some capacity with a short period of relaxation. This capacity recovery phenomenon is validated experimentally for different discharge currents and relaxation durations. The transport-limited discharge behavior of Li-S cells highlights the importance of optimizing the electrolyte loading and electrolyte transport property in Li-S cells.

A computational fluid dynamics approach to nucleation in the water-sulfuric acid system.

Science.gov (United States)

Herrmann, E; Brus, D; Hyvärinen, A-P; Stratmann, F; Wilck, M; Lihavainen, H; Kulmala, M

2010-08-12

This study presents a computational fluid dynamics modeling approach to investigate the nucleation in the water-sulfuric acid system in a flow tube. On the basis of an existing experimental setup (Brus, D.; Hyvärinen, A.-P.; Viisanen, Y.; Kulmala, M.; Lihavainen, H. Atmos. Chem. Phys. 2010, 10, 2631-2641), we first establish the effect of convection on the flow profile. We then proceed to simulate nucleation for relative humidities of 10, 30, and 50% and for sulfuric acid concentration between 10(9) to 3 x 10(10) cm(-3). We describe the nucleation zone in detail and determine how flow rate and relative humidity affect its characteristics. Experimental nucleation rates are compared to rates gained from classical binary and kinetic nucleation theory as well as cluster activation theory. For low RH values, kinetic theory yields the best agreement with experimental results while binary nucleation best reproduces the experimental nucleation behavior at 50% relative humidity. Particle growth is modeled for an example case at 50% relative humidity. The final simulated diameter is very close to the experimental result.

Differential electrolytic potentiometric titration method for the determination of ciprofloxacin in drug formulations.

Science.gov (United States)

Abulkibash, Abdalla M; Sultan, Salah M; Al-Olyan, Abeer M; Al-Ghannam, Sheikha M

2003-10-17

A simple and rapid differential electrolytic potentiometric titration method for the determination of ciprofloxacin was developed. The work is based on the fast complexation reaction between iron(III) and ciprofloxacin in a ratio of 1:3, respectively, in sulfuric acid media of 0.09 mol dm(-3). Among the electrodes tested silver amalgam electrodes were found to be a suitable indicating system. By applying a current density of 0.5 muA cm(-2) to these electrodes and using iron(III) solution of 0.097 mol dm(-3) as a titrant, normal titration curves were obtained. The method was successfully applied for the determination of ciprofloxacin in drug formulations as low as 4.0 ppm.

40 CFR 721.3130 - Sulfuric acid, mono-C9-11-alkyl esters, sodium salts.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfuric acid, mono-C9-11-alkyl esters, sodium salts. 721.3130 Section 721.3130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... significant new uses are: (i) Industrial, commercial, and consumer activities. Requirements as specified in...

Reevaluation of the phenol-sulfuric acid reaction for the estimation of hexoses and pentoses.

Science.gov (United States)

Rao, P; Pattabiraman, T N

1989-08-15

Evidence is provided to show that in the conventional phenol-sulfuric acid reaction procedure, phenol underwent sulfonation in situ and the phenolsulfonic acid formed decreased the color intensity for hydroxymethyl furfural (HMF), furfural, and many hexoses and pentoses tested. A modified method is described to overcome this problem in which phenol was added after the dehydration of carbohydrates by sulfuric acid and after cooling the system. The color intensity around 475-485 nm for different compounds was fairly proportional to the amount of furfural derivatives (absorption at 310-320 nm) formed from the sugars in the modified method unlike in the conventional procedure. The studies also show that for condensation of HMF derivatives with phenol, heat is not necessary. The color intensity in the modified method also increased compared to that in the conventional method. The increase in the modified method compared to that in the conventional method was 6.0-fold for furfural, 9.1-fold for hydroxymethyl furfural, 3.7-fold for fructose, 2.3-fold for xylose, and 2.0-fold for glucose and arabinose. The possible reasons for this differential increase are discussed.

Improved electrolyte for zinc-bromine flow batteries

Science.gov (United States)

Wu, M. C.; Zhao, T. S.; Wei, L.; Jiang, H. R.; Zhang, R. H.

2018-04-01

Conventional zinc bromide electrolytes offer low ionic conductivity and often trigger severe zinc dendrite growth in zinc-bromine flow batteries. Here we report an improved electrolyte modified with methanesulfonic acid, which not only improves the electrolyte conductivity but also ameliorates zinc dendrite. Experimental results also reveal that the kinetics and reversibility of Zn2+/Zn and Br2/Br- are improved in this modified electrolyte. Moreover, the battery's internal resistance is significantly reduced from 4.9 to 2.0 Ω cm2 after adding 1 M methanesulfonic acid, thus leading to an improved energy efficiency from 64% to 75% at a current density of 40 mA cm-2. More impressively, the battery is capable of delivering an energy efficiency of about 78% at a current density of as high as 80 mA cm-2 when the electrode is replaced by a thermally treated one. Additionally, zinc dendrite growth is found to be effectively suppressed in methanesulfonic acid supported media, which, as a result, enables the battery to be operated for 50 cycles without degradation, whereas the one without methanesulfonic acid suffers from significant decay after only 40 cycles, primarily due to severe zinc dendrite growth. These superior results indicate methanesulfonic acid is a promising supporting electrolyte for zinc-bromine flow batteries.

Toxicity of nickel and silver to Nostoc muscorum: interaction with ascorbic acid, glutathione, and sulfur-containing amino acids.

Science.gov (United States)

Rai, L C; Raizada, M

1987-08-01

Exposure of Nostoc muscorum to different concentrations of Ni and Ag brought about reduction in growth, carbon fixation, heterocyst production, and nitrogenase activity and increase in the loss of ions (K+, Na+). In an attempt to ameliorate the toxicity of test metals by ascorbic acid, glutathione, and sulfur-containing amino acids (L-cysteine and L-methionine), it was found that the level of protection by ascorbic acid and glutathione was more for Ag than Ni. However, metal-induced inhibition of growth and carbon fixation was equally ameliorated by methionine. But the level of protection by cysteine was quite different, i.e., 27% for Ni and 22% for Ag. Protection of metal toxicity in N. muscorum by amino acids lends further support to self-detoxifying ability of cyanobacteria because they are known to synthesize all essential amino acids.

Microbial contributions to coupled arsenic and sulfur cycling in the acid-sulfide hot spring Champagne Pool, New Zealand.

Science.gov (United States)

Hug, Katrin; Maher, William A; Stott, Matthew B; Krikowa, Frank; Foster, Simon; Moreau, John W

2014-01-01

Acid-sulfide hot springs are analogs of early Earth geothermal systems where microbial metal(loid) resistance likely first evolved. Arsenic is a metalloid enriched in the acid-sulfide hot spring Champagne Pool (Waiotapu, New Zealand). Arsenic speciation in Champagne Pool follows reaction paths not yet fully understood with respect to biotic contributions and coupling to biogeochemical sulfur cycling. Here we present quantitative arsenic speciation from Champagne Pool, finding arsenite dominant in the pool, rim and outflow channel (55-75% total arsenic), and dithio- and trithioarsenates ubiquitously present as 18-25% total arsenic. In the outflow channel, dimethylmonothioarsenate comprised ≤9% total arsenic, while on the outflow terrace thioarsenates were present at 55% total arsenic. We also quantified sulfide, thiosulfate, sulfate and elemental sulfur, finding sulfide and sulfate as major species in the pool and outflow terrace, respectively. Elemental sulfur concentration reached a maximum at the terrace. Phylogenetic analysis of 16S rRNA genes from metagenomic sequencing revealed the dominance of Sulfurihydrogenibium at all sites and an increased archaeal population at the rim and outflow channel. Several phylotypes were found closely related to known sulfur- and sulfide-oxidizers, as well as sulfur- and sulfate-reducers. Bioinformatic analysis revealed genes underpinning sulfur redox transformations, consistent with sulfur speciation data, and illustrating a microbial role in sulfur-dependent transformation of arsenite to thioarsenate. Metagenomic analysis also revealed genes encoding for arsenate reductase at all sites, reflecting the ubiquity of thioarsenate and a need for microbial arsenate resistance despite anoxic conditions. Absence of the arsenite oxidase gene, aio, at all sites suggests prioritization of arsenite detoxification over coupling to energy conservation. Finally, detection of methyl arsenic in the outflow channel, in conjunction with

A binder-free sulfur/reduced graphene oxide aerogel as high performance electrode materials for lithium sulfur batteries

Science.gov (United States)

Nitze, Florian; Agostini, Marco; Lundin, Filippa; Palmqvist, Anders E. C.; Matic, Aleksandar

2016-12-01

Societies’ increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3-5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of “no battery without binder” and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm2 after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.

Understanding the role of lithium polysulfide solubility in limiting lithium-sulfur cell capacity

International Nuclear Information System (INIS)

Shen, Chao; Xie, Jianxin; Zhang, Mei; Andrei, Petru; Hendrickson, Mary; Plichta, Edward J.; Zheng, Jim P.

2017-01-01

Highlights: •At normal rate, LiPS soluble reaction pathway dominates the discharge process. •Reduction of sulfur to Li 2 S 8 is not inhibited by high Li 2 S 8 concentration. •Subsequent LiPS electrochemical reactions are restricted by LiPS solubility. •Specific energy of the Li-S cell was reevaluated considering LiPS solubility. -- Abstract: Although the cathode of lithium-sulfur (Li-S) batteries has a theoretical specific capacity of 1,672 mAh g −1 , its practical capacity is much smaller than this value and depends on the electrolyte/sulfur ratio. The operation of Li-S batteries under lean electrolyte conditions can be challenging, especially in the case when the solubility of lithium polysulfide (LiPS) sets an upper bound for polysulfide dissolution. In this work, specially designed cathode structures and electrolyte configurations were built in order to analyze the effects of LiPS solubility on cell capacity. Two reaction pathways involving the reduction of LiPS in liquid and solid phase are proposed and analyzed. We show that at discharge rates above 0.4 mA cm −2 the reaction in the liquid phase dominates the discharge process. Once the electrolyte becomes saturated, the solid phase LiPS cannot be further reduced and does not contribute to the capacity of the cells. This phenomenon prevents Li-S batteries from achieving their high theoretical specific capacity. Finally, the specific energy of the Li-S cell is reevaluated and discussed considering the limitation imposed by LiPS solubility.

SUNRAYCE 95: Working safely with lead-acid batteries and photovoltaic power systems

Energy Technology Data Exchange (ETDEWEB)

DePhillips, M.P.; Moskowitz, P.D.; Fthenakis, V.M. [Brookhaven National Lab., Upton, NY (United States). Biomedical and Environmental Assessment Group

1994-05-27

This document is a power system and battery safety handbook for participants in the SUNRAYCE 95 solar powered electric vehicle program. The topics of the handbook include batteries, photovoltaic modules, safety equipment needed for working with sulfuric acid electrolyte and batteries, battery transport, accident response, battery recharging and ventilation, electrical risks on-board vehicle, external electrical risks, electrical risk management strategies, and general maintenance including troubleshooting, hydrometer check and voltmeter check.

Solvent-Free Biginelli Condensation using Tungstate Sulfuric Acid: a Powerful and Reusable Catalyst for Selective Synthesis

Directory of Open Access Journals (Sweden)

Rezvan Rezaee Nasab

2014-07-01

Full Text Available Tungstate sulfuric acid (TSA has been prepared and used as a recyclable catalyst for the Biginelli syn-thesis of some biologically active quinazolinones/thiones under solvent-free conditions. This method has advantages such as the avoidance of organic solvents, high yield of pure products, short reaction times, and operational simplicity.  © 2014 BCREC UNDIP. All rightsReceived: 28th April 2014; Revised: 15th May 2014; Accepted: 26th May 2014[ How to Cite: Nasab, R.R., Karami, B., Khodabakhshi, S. (2014. Selective Solvent‐free Biginelli Condensation using Tungstate Sulfuric Acid as Powerful and Reusable Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (2: 142-154. (doi:10.9767/bcrec.9.2.6794.148-154][ Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.2.6794.148-154

Effects of simulated rain acidified with sulfuric acid on host-parasite interactions

Science.gov (United States)

D. S. Shriner

1976-01-01

Wind-blown rain, rain splash, and films of free moisture play important roles in the epidemiology of many plant diseases. The effects of simulated rain acidified with sulfuric acid were studied on several host-parasite systems. Plants were exposed, in greenhouse or field, to simulated rain of pH 3.2 ? 0.1 or pH 6.0 ? 0.2. Simulated "rain" of pH 3.2 resulted...

Development and characterization of acid-doped polybenzimidazole/sulfonated polysulfone blend polymer electrolytes for fuel cells

DEFF Research Database (Denmark)

Hasiotis, C.; Li, Qingfeng; Deimede, V.

2001-01-01

Polymeric membranes from blends of sulfonated polysulfones (SPSF) and polybenzimidazole (PBI) doped with phosphoric acid were developed as potential high-temperature polymer electrolytes for fuel cells and other electrochemical applications. The water uptake and acid doping of these polymeric...... membranes were investigated. Ionic conductivity of the membranes was measured in relation to temperature, acid doping level, sulfonation degree of SPSF, relative humidity, and blend composition. The conductivity of SPSF was of the order of 10/sup -3/ S cm/sup -1/. In the case of blends of PBI and SPSF...

Silica Sulfuric Acid: An Eco-Friendly and Reusable Catalyst for Synthesis of Benzimidazole Derivatives

Directory of Open Access Journals (Sweden)

Bahareh Sadeghi

2013-01-01

Full Text Available Silica sulfuric acid (SiO2-OSO3H as an eco-friendly, readily available, and reusable catalyst is applied to benzimidazole derivatives synthesis under reflux in ethanol. The procedure is very simple and the products are isolated with an easy workup in good-to-excellent yields.

Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

DEFF Research Database (Denmark)

Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

2018-01-01

how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

New Polymer Electrolyte Membranes Based on Acid Doped PBI For Fuel Cells Operating above 100°C

DEFF Research Database (Denmark)

Li, Qingfeng

2003-01-01

The technical achievement and challenges for the PEMFC technology based on perfluorosulfonic acid (PFSA) polymer membranes (e.g. Nafion®) are briefly discussed. The newest development for alternative polymer electrolytes for operation above 100°C. As one of the successful approaches to high...... operational temperatures, the development and evaluation of acid doped PBI membranes are reviewed, covering polymer synthesis, membrane casting, acid doping, physiochemical characterization and fuel cell tests....

Production of spent mushroom substrate hydrolysates useful for cultivation of Lactococcus lactis by dilute sulfuric acid, cellulase and xylanase treatment.

Science.gov (United States)

Qiao, Jian-Jun; Zhang, Yan-Fei; Sun, Li-Fan; Liu, Wei-Wei; Zhu, Hong-Ji; Zhang, Zhijun

2011-09-01

Spent mushroom substrate (SMS) was treated with dilute sulfuric acid followed by cellulase and xylanase treatment to produce hydrolysates that could be used as the basis for media for the production of value added products. A L9 (3(4)) orthogonal experiment was performed to optimize the acid treatment process. Pretreatment with 6% (w/w) dilute sulfuric acid at 120°C for 120 min provided the highest reducing sugar yield of 267.57 g/kg SMS. No furfural was detected in the hydrolysates. Exposure to 20PFU of cellulase and 200 XU of xylanase per gram of pretreated SMS at 40°C resulted in the release of 79.85 g/kg or reducing sugars per kg acid pretreated SMS. The dilute sulfuric acid could be recycled to process fresh SMS four times. SMS hydrolysates neutralized with ammonium hydroxide, sodium hydroxide, or calcium hydroxide could be used as the carbon source for cultivation of Lactococcus lactis subsp. lactis W28 and a cell density of 2.9×10(11)CFU/mL could be obtained. The results provide a foundation for the development of value-added products based on SMS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Preparation and DMFC performance of a sulfophenylated poly(arylene ether ketone) polymer electrolyte membrane

Energy Technology Data Exchange (ETDEWEB)

Liu Baijun, E-mail: liubj@jlu.edu.c [College of Chemistry, Jilin University, Changchun 130012 (China); Hu Wei [College of Chemistry, Jilin University, Changchun 130012 (China); Kim, Yu Seung [Los Alamos National Laboratory, Electronic and Electrochemical Materials and Devices, Los Alamos, NM 87545 (United States); Zou Haifeng [College of Chemistry, Jilin University, Changchun 130012 (China); Robertson, Gilles P. [Institute for Chemical Process and Environmental Technology, National Research Council, Ottawa, Ontario K1A 0R6 (Canada); Jiang Zhenhua [College of Chemistry, Jilin University, Changchun 130012 (China); Guiver, Michael D. [Institute for Chemical Process and Environmental Technology, National Research Council, Ottawa, Ontario K1A 0R6 (Canada); Department of Energy Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

2010-04-15

A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily prepared PEEKK by post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported similarly structured analogues and MEAs derived from comparative Nafion membranes.

Spectrophotometric study of the protonation processes of some indole derivatives in sulfuric acid

Directory of Open Access Journals (Sweden)

GORAN M. STOJKOVIC

1999-12-01

Full Text Available The protonation of 3-methylindole, D-tryptophan, 3-formylindole, 3-acetylindole and indolyl-2-carboxylic acid in sulfuric acid media was studied by UV spectro-scopy. The measurement of the absorbance at four selected wavelengths enabled the calculation of the corresponding molar absorptivities. The results were used to calculate the pKa value of the protonated form of the indole derivatives by the Hammett Method. The Hammett postulate (the slope of the plot log [c(BH+/c(B] vs. H should be equal to 1 was tested. The dissociation constants and solvent parameter m* were also obtained by applying the Excess Acidity Method. The position of the additional protons in the protonated compounds is discussed.

Gaseous ion-composition measurements in the young exhaust plume of jet aircraft at cruising altitudes. Implications for aerosols and gaseous sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Arnold, F.; Wohlfrom, K.H.; Klemm, M.; Schneider, J.; Gollinger, K. [Max-Planck-Inst. for Nuclear Physics, Heidelberg (Germany); Schumann, U.; Busen, R. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

1997-12-31

Mass spectrometric measurements were made in the young exhaust plume of an Airbus (A310) at cruising altitudes at distances between 400 and 800 m behind the Airbus (averaged plume age: 3.4 sec). The measurements indicate that gaseous sulfuric acid (GSA) number densities were less than 1.3 x 10{sup 8} cm{sup -3} which is smaller than the expected total sulfuric acid. Hence the missing sulfuric acid must have been in the aerosol phase. These measurements also indicate a total aerosol surface area density A{sub T} {<=} 5.4 x 10{sup -5} cm{sup 2} per cm{sup 3} which is consistent with simultaneously measured soot and water contrail particles. However, homogeneous nucleation leading to (H{sub 2}SO{sub 4}){sub x}(H{sub 2}O){sub y}-clusters can not be ruled out. (author) 16 refs.

Gaseous ion-composition measurements in the young exhaust plume of jet aircraft at cruising altitudes. Implications for aerosols and gaseous sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Arnold, F; Wohlfrom, K H; Klemm, M; Schneider, J; Gollinger, K [Max-Planck-Inst. for Nuclear Physics, Heidelberg (Germany); Schumann, U; Busen, R [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

1998-12-31

Mass spectrometric measurements were made in the young exhaust plume of an Airbus (A310) at cruising altitudes at distances between 400 and 800 m behind the Airbus (averaged plume age: 3.4 sec). The measurements indicate that gaseous sulfuric acid (GSA) number densities were less than 1.3 x 10{sup 8} cm{sup -3} which is smaller than the expected total sulfuric acid. Hence the missing sulfuric acid must have been in the aerosol phase. These measurements also indicate a total aerosol surface area density A{sub T} {<=} 5.4 x 10{sup -5} cm{sup 2} per cm{sup 3} which is consistent with simultaneously measured soot and water contrail particles. However, homogeneous nucleation leading to (H{sub 2}SO{sub 4}){sub x}(H{sub 2}O){sub y}-clusters can not be ruled out. (author) 16 refs.

Uranium extraction from sulfuric acid solution using anion exchange resin

International Nuclear Information System (INIS)

Sheta, M. E.; Abdel Aal, M. M.; Kandil, A. T.

2012-12-01

Uranium is currently recovered from sulfuric acid leach liquor using anion exchange resin as Amberlite IRA 402 (CT). This technology is based on fact that, uranium exists as anionic complexes. This takes place by controlling the pH of the solution, agitation time, temperature and resin to solution ratio (R/S). In this work, batch stirrer tank used for uranium extraction from sulfate medium and after extraction, elution process was done using 1M NaCl solution. After extraction and elution process, the resin was separated from the system and uranium was determined in the solution. (Author)

Codeposition of either molybdenum or tungsten with the metals of iron group 8. The citric acid influence on codeposition of nickel and tungsten from sulphamic electrolytes

International Nuclear Information System (INIS)

Bernotas, A.; Kadziauskiene, V.; Jasulaitiene, V.

1995-01-01

The influence of citric acid on codeposition of Ni and W from sulphamic electrolytes was investigated by measuring the hydrogen content in electro deposits and determining the current efficiency and the alloy composition by chemical analysis and X-ray spectroscopy. The reduction of W(VI) to W(0) in the electrolyte with and without citric acid was found to proceed through the formation of tungsten compounds of intermediate oxidation state. It is supposed that an increased amount of tungsten in the alloys with the increase of citric acid concentration in the electrolyte (to 0.042 mol/l) is caused by a large amount of W(IV) at the cathodic surface. The further increase of the concentration of citric acid in the electrolyte causes a decrease of tungsten amount in the alloy, because the blocking of the metallic surface of Ni and W by W compounds of intermediate oxidation state makes the reduction of W(VI) to W(0) more difficult. (author). 8 refs., 3 figs., 1 tab

Investigation of rare earths sorption from sulfuric- and hydrochloric media

International Nuclear Information System (INIS)

Nikonov, V.N.; Mikhlin, E.B.; Norina, T.M.; Afonina, T.A.

1978-01-01

A rate of equilibrium attainment has been studied during REE sorption from sulfuric and hydrochloric acid solutions and pulps. It has been shown that equilibrium upon sorption from hydrochloric acid solutions is attained faster than from sulfuric acid solutions. Equilibrium upon sorption from pulps is attained considerably slower than upon sorption from solutions. In all cases REM of cerium subgroup are sorbed better. An effect has been studied of the medium acidity on sorbability of REM and elements of iron and calcium impurities. It has been established that sorbability of these elements decreases with increasing acid concentration. Selectivity of REM sorption from sulfuric acid solutions decreases with a rise in H 2 SO 4 concentration in the solution. For hydrochloric acid solutions it remains constant in a wide range of HCl concentrations. Sorption leaching of REM from concentrates and cakes of sulfuric and hydrochloric acids in the presence of KU-2 leads to high technical and economic indexes: extraction with respect to the total amount of REM and yttrium into a commercial product is 76-86% for sulfuric acid solutions and 81-90% for hydrochloric solutions

A prospective randomized trial of two solutions for intrapartum amnioinfusion: effects on fetal electrolytes, osmolality, and acid-base status.

Science.gov (United States)

Pressman, E K; Blakemore, K J

1996-10-01

Our purpose was to compare the effects of intrapartum amnioinfusion with normal saline solution versus lactated Ringer's solution plus physiologic glucose on neonatal electrolytes and acid-base balance. Patients undergoing amnioinfusion for obstetric indications were randomized to receive normal saline solution or lactated Ringer's solution plus physiologic glucose at standardized amnioinfusion rates. Data were collected prospectively on maternal demographics, course of labor, and maternal and neonatal outcome. Arterial cord blood was obtained for analysis of electrolytes, glucose, osmolality, lactic acid, and blood gases. Control subjects with normal fetal heart rate patterns, and clear amniotic fluid not receiving amnioinfusion were studied concurrently. Data were collected on 59 patients (21 normal saline solution, 18 lactated Ringer's solution plus physiologic glucose, and 20 controls). Maternal demographics, course of labor, and neonatal outcome were similar in all three groups. Cesarean sections were performed more often in the amnioinfusion groups (33.3% for normal saline solution, 38.9% for lactated Ringer's solution plus physiologic glucose) than in the control group (5.0%), p amnioinfusion with either solution. Intrapartum amnioinfusion with normal saline solution or lactated Ringer's solution plus physiologic glucose has no effect on neonatal electrolytes or acid-base balance.

Plutonium oxides analysis. Sulfur potentiometric analysis

International Nuclear Information System (INIS)

Anon.

Total sulfur determination (sulfur, sulfates, sulfides ...) in plutonium oxides, suitable for sulfate ion content between 0.003 percent to 0.2 percent, by dissolution in nitric hydrofluoric acid, nitrates elimination, addition of hydrochloric acid and reduction in hydrogen sulfide which is carried by an inert gas and neutralized by sodium hydroxide. Sodium sulfide is titrated with mercuric acetate by constant intensity potentiometry [fr

Correlation of electrolyte-derived inclusions to crystallization in the early stage of anodic oxide film growth on titanium

Energy Technology Data Exchange (ETDEWEB)

Jaeggi, C., E-mail: christian.jaeggi@empa.ch [Empa, Swiss Federal Laboratories for Materials Testing and Research, Advanced Materials Processing Laboratory, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Parlinska-Wojtan, M., E-mail: magdalena.parlinska@empa.ch [Empa, Swiss Federal Laboratories for Materials Testing and Research, Center for Electron Microscopy, Ueberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Kern, P., E-mail: Philippe.Kern@neopac.ch [Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland)

2012-01-01

Pure titanium has been subjected to anodization in sulfuric and phosphoric acid. For a better understanding of the oxide growth and properties of the final film, with a particular interest focused on the solution anions in the early stage of crystallization, microstructural analyses (Raman, Transmission Electron Microscopy [TEM]) of the oxide films were correlated to chemical depth profiling by glow discharge optical emission spectroscopy (GDOES). Raman spectroscopy shows that crystallization of the oxide films starts at potentials as low as 10-20 V. The onset of crystallization and the ongoing increase in crystallinity with increasing anodization potentials had already earlier been correlated to ac-impedance measurements [Jaeggi et al., Surf. Interface Anal. 38 (2006) 182]. TEM observations show a clear difference in the early phase of crystallization between oxides grown in 1 M sulfuric acid compared to 1 M phosphoric acid. Moreover, independent of electrolyte type, nano-sized pores from oxygen bubbles formation were revealed in the central part of the films. Until now, oxygen bubbles inside an anodically grown oxide have not been observed before without the presence of crystalline regions nearby. A growth model is proposed, in which the different starting locations of crystallization inside the films are correlated to the presence of the acid anions as residues in the film, as found by GDOES chemical depth-profiling.

Fabrication of the micro/nano-structure superhydrophobic surface on aluminum alloy by sulfuric acid anodizing and polypropylene coating.

Science.gov (United States)

Wu, Ruomei; Liang, Shuquan; Liu, Jun; Pan, Anqiang; Yu, Y; Tang, Yan

2013-03-01

The preparation of the superhydrophobic surface on aluminum alloy by anodizing and polypropylene (PP) coating was reported. Both the different anodizing process and different PP coatings of aluminum alloy were investigated. The effects of different anodizing conditions, such as electrolyte concentration, anodization time and current on the superhydrophobic surface were discussed. By PP coating after anodizing, a good superhydrophobic surface was facilely fabricated. The optimum conditions for anodizing were determined by orthogonal experiments. After the aluminium-alloy was grinded with 600# sandpaper, pretreated by 73 g/L hydrochloric acid solution at 1 min, when the concentration of sulfuric acid was 180 g/L, the concentration of oxalic acid was 5 g/L, the concentration of potassium dichromate was 10 g/L, the concentration of chloride sodium was 50 g/L and 63 g/L of glycerol, anodization time was 20 min, and anodization current was 1.2 A/dm2, anodization temperature was 30-35 degrees C, the best micro-nanostructure aluminum alloy films was obtained. On the other hand, the PP with different concentrations was used to the PP with different concentrations was used to coat the aluminum alloy surface after anodizing. The results showed that the best superhydrophobicity was achieved by coating PP, and the duration of the superhydrophobic surface was improved by modifying the coat the aluminum alloy surface after anodizing. The results showed that the best superhydrophobicity was surface with high concentration PP. The morphologies of micro/nano-structure superhydrophobic surface were further confirmed by scanning electron microscope (SEM). The material of PP with the low surface free energy combined with the micro/nano-structures of the surface resulted in the superhydrophobicity of the aluminum alloy surface.

A statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore

Directory of Open Access Journals (Sweden)

Mendes F.D.

2003-01-01

Full Text Available The high grade of copper in the Igarapé Bahia (Brazil gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%.

Once-through hybrid sulfur process for nuclear hydrogen production

International Nuclear Information System (INIS)

Jeong, Y. H.

2008-01-01

Increasing concern about the global climate change spurs the development of low- or zero-carbon energy system. Nuclear hydrogen production by water electrolysis would be the one of the short-term solutions, but low efficiency and high production cost (high energy consumption) is the technical hurdle to be removed. In this paper the once-through sulfur process composed of the desulfurization and the water electrolysis systems is proposed. Electrode potential for the conventional water electrolysis (∼2.0 V) can be reduced significantly by the anode depolarization using sulfur dioxide: down to 0.6 V depending on the current density This depolarized electrolysis is the electrolysis step of the hybrid sulfur process originally proposed by the Westinghouse. However; recycling of sulfur dioxide requires a high temperature heat source and thus put another technical hurdle on the way to nuclear hydrogen production: the development of high temperature nuclear reactors and corresponding sulfuric acid decomposition system. By the once-through use of sulfur dioxide rather than the closed recycle, the hurdle can be removed. For the sulfur feed, the desulfurization system is integrated into the water electrolysis system. Fossil fuels include a few percent of sulfur by weight. During the refinement or energy conversion, most of the sulfur should be separated The separated sulfur can be fed to the water electrolysis system and the final product would be hydrogen and sulfuric acid, which is number one chemical in the world by volume. Lowered electrode potential and additional byproduct, the sulfuric acid, can provide economically affordable hydrogen. In this study, the once-through hybrid sulfur process for hydrogen production was proposed and the process was optimized considering energy consumption in electrolysis and sulfuric acid concentration. Economic feasibility of the proposed process was also discussed. Based on currently available experimental data for the electrode

Corrosion resistance of materials of construction for high temperature sulfuric acid service in thermochemical IS process. Alloy 800, Alloy 600, SUSXM15J1 and SiC

International Nuclear Information System (INIS)

Tanaka, Nobuyuki; Onuki, Kaoru; Shimizu, Saburo; Yamaguchi, Akihisa

2006-01-01

Exposure tests of candidate materials were carried out up to 1000 hr in the sulfuric acid environments of thermochemical hydrogen production IS process, focusing on the corrosion of welded portion and of crevice area. In the gas phase sulfuric acid decomposition condition at 850degC, welded samples of Alloy 800 and of Alloy 600 showed the same good corrosion resistance as the base materials. In the boiling condition of 95 wt% sulfuric acid solution, test sample of SiC showed the same good corrosion resistance. Also negligible corrosion was observed in crevice corrosion. (author)

The simulation of the temperature effects on the microhardness of anodic alumina oxide layers

Directory of Open Access Journals (Sweden)

M. Gombár

2014-01-01

Full Text Available In order to improve the mechanical properties of the layer deposited by anodic oxidation of aluminum on the material EN AW-1050 H24, in the contribution was investigated the microhardness of the deposited layer as a function of the physic-chemical factors affecting in the process of anodic oxidation at the constant anodic current density J = 3 A.dm-2 in electrolyte formed by sulfuric acid and oxalic acid, with the emphasis on the influence of electrolyte temperature in the range – 1,78 °C to 45,78 °C. The model of the studied dependence was compiled based on mathematical and statistical analysis of matrix from experimental obtained data from composite rotation plan of experiment with five independent variable factors (amount of sulfuric acid in the electrolyte, the amount of oxalic acid in the electrolyte, electrolyte, anodizing time and applied voltage.

Study of vanadium(IV) species and corresponding electrochemical performance in concentrated sulfuric acid media

International Nuclear Information System (INIS)

Wu Xuewen; Wang Jinjin; Liu Suqin; Wu Xiongwei; Li Sha

2011-01-01

Highlights: → Two new UV/Vis absorbance peaks are found in V(IV) sulfuric acid solutions. → We give the structural information on the new corresponding V(IV) species. → Reaction route is given with increasing sulfuric acid and V(IV) concentrations. → We find V(IV) species corresponding to the reversible electrochemical reaction. → A mixed-valence intermediate is invoked in the reversible reaction. - Abstract: The vanadium(IV) ion is found to form the [VO(SO 4 )(H 2 O) 4 ].H 2 O complex, as well as the dimer, [VO(H 2 O) 3 ] 2 (μ-SO 4 ) 2 , in concentrated H 2 SO 4 media. Their formation mechanisms were investigated by UV-Visible spectroscopy (UV-Vis), Raman spectroscopy, X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). UV-Vis spectroscopy study showed that [VO(SO 4 )(H 2 O) 4 ].H 2 O concentration in H 2 SO 4 solution was proportional to concentrations of VO 2+ and SO 4 2- . The increased deviation from the near centrosymmetry of the octahedral complexes is due to the replacement of an equatorial water oxygen in [VO(H 2 O) 5 ]SO 4 by a sulfate oxygen in [VO(SO 4 )(H 2 O) 4 ].H 2 O. The dimer shows symmetrical structure, which correlates very well with non-activity in UV-Vis spectroscopic analysis. Structural information on both vanadium(IV) species can be confirmed by Raman and XRD measurements of crystals from the supersaturated solution of VOSO 4 in 1 M, 6 M and 12 M sulfuric acid. A solution of vanadium(IV) (0.05 M) in 12 M H 2 SO 4 , in which the vanadium(IV) species is [VO(H 2 O) 3 ] 2 (μ-SO 4 ) 2 , exhibits a reversible redox behavior near 1.14 V (vs. SCE) on the carbon paper electrode.

The effect of acidity of electrolyte on the porosity and the nanostructure morphology of electrolytic manganese dioxide

International Nuclear Information System (INIS)

Adelkhani, H.

2012-01-01

The effects of acidity of electrolyte (pH) on the hysteresis behavior, the specific surface area, and nanostructure morphology of electrolytic manganese dioxides (EMDs) have been studied by using the Barrett-Joyner-Halenda (BJH) analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) images analysis. EMD samples are electrodeposited at a variable pH (6 to 1) and many fixed pH (2, 3, 4, 5, and 6). Results indicate that pH play key roles in the characteristics of EMD. The samples obtained at low pH (2 and 3) show multi-branched morphology and represent a H4 hysteresis loop. At pH 4 and 5, a uniform and dense structure of MnO 2 is obtained without hysteresis behavior. The sample electrodeposited at pH 6 shows a regular reticulate, that its adsorption-desorption isotherm show hysteresis behavior. By electrodeposition at a variable pH, the sample shows a cauliflower-like and multi-branched form. From the viewpoint of classification of isotherm, pH strongly affects on Type of isotherm. The results show that γ-MnO 2 is as main-product of electrodeposition and α-MnO 2 and β-MnO 2 were obtained as side-product at low and high pH, respectively.

The effect of acidity of electrolyte on the porosity and the nanostructure morphology of electrolytic manganese dioxide

Energy Technology Data Exchange (ETDEWEB)

Adelkhani, H., E-mail: adelkhani@hotmail.com [Material Research School, NSTRI, P.O. Box: 14395-836, Tehran (Iran, Islamic Republic of)

2012-06-15

The effects of acidity of electrolyte (pH) on the hysteresis behavior, the specific surface area, and nanostructure morphology of electrolytic manganese dioxides (EMDs) have been studied by using the Barrett-Joyner-Halenda (BJH) analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) images analysis. EMD samples are electrodeposited at a variable pH (6 to 1) and many fixed pH (2, 3, 4, 5, and 6). Results indicate that pH play key roles in the characteristics of EMD. The samples obtained at low pH (2 and 3) show multi-branched morphology and represent a H4 hysteresis loop. At pH 4 and 5, a uniform and dense structure of MnO{sub 2} is obtained without hysteresis behavior. The sample electrodeposited at pH 6 shows a regular reticulate, that its adsorption-desorption isotherm show hysteresis behavior. By electrodeposition at a variable pH, the sample shows a cauliflower-like and multi-branched form. From the viewpoint of classification of isotherm, pH strongly affects on Type of isotherm. The results show that {gamma}-MnO{sub 2} is as main-product of electrodeposition and {alpha}-MnO{sub 2} and {beta}-MnO{sub 2} were obtained as side-product at low and high pH, respectively.

Effects of sulfur oxides on eicosanoids

International Nuclear Information System (INIS)

Chen, L.C.; Miller, P.D.; Amdur, M.O.

1989-01-01

Ultrafine metal oxides and SO2 react during coal combustion or smelting operations to form primary emissions coated with an acidic SOx layer. Ongoing work in this laboratory has examined the effects of sulfur oxides on pulmonary functions of guinea pigs. We have previously reported that 20 micrograms/m3 acidic sulfur oxide as a surface layer on ultrafine ZnO particles decreases lung volumes, decreases carbon monoxide diffusing capacity, and causes lung inflammation in guinea pigs after 4 daily 3-h exposures. It also produces bronchial hypersensitivity following a single 1-h exposure. The importance of this surface layer is demonstrated by our observation that 200 micrograms/m3 of sulfuric acid droplets of equivalent size are needed to produce the same degree of hypersensitivity. This study characterized the concentration-dependent effects of in vivo exposures to sulfur oxides on arachidonic acid metabolism in the guinea pig lung, and investigated the time course and the relation between eicosanoid composition and pulmonary functions. We focused specifically on four cyclooxygenase metabolites of arachidonic acid, that is, prostaglandins (PG) E1, F2 alpha, 6-keto prostaglandin F1 alpha, and thromboxane (Tx) B2, and two groups of sulfidopeptide leukotrienes (C4, D4, E4, and F4). Guinea pigs were exposed to ultrafine ZnO aerosol (count median diameter = 0.05 microns, sigma g = 1.80) with a layer of acidic sulfur oxide on the surface of the particles. Lung lavage was collected after exposures, and the levels of arachidonic acid metabolites were determined using radioimmunoassay (RIA). Concentration-dependent promotion of PGF2 alpha and concentration-dependent suppression of LtB4 were observed. The increased PGF2 alpha was associated with depressed vital capacity and diffusing capacity of the lungs measured in guinea pigs exposed to the same atmosphere described in a previous study

Comparative analysis of the effect of pretreating aspen wood with aqueous and aqueous-organic solutions of sulfuric and nitric acid on its reactivity during enzymatic hydrolysis

DEFF Research Database (Denmark)

Dotsenko, Gleb; Osipov, D. O.; Zorov, I. N.

2016-01-01

The effect of aspen wood pretreatment methods with the use of both aqueous solutions of sulfuric and nitric acids and aqueous-organic solutions (ethanol, butanol) of sulfuric acid (organosolv) on the limiting degree of conversion of this type of raw material into simple sugars during enzymatic...

Ultrathin Hierarchical Porous Carbon Nanosheets for High-Performance Supercapacitors and Redox Electrolyte Energy Storage.

Science.gov (United States)

Jayaramulu, Kolleboyina; Dubal, Deepak P; Nagar, Bhawna; Ranc, Vaclav; Tomanec, Ondrej; Petr, Martin; Datta, Kasibhatta Kumara Ramanatha; Zboril, Radek; Gómez-Romero, Pedro; Fischer, Roland A

2018-04-01

The design of advanced high-energy-density supercapacitors requires the design of unique materials that combine hierarchical nanoporous structures with high surface area to facilitate ion transport and excellent electrolyte permeability. Here, shape-controlled 2D nanoporous carbon sheets (NPSs) with graphitic wall structure through the pyrolysis of metal-organic frameworks (MOFs) are developed. As a proof-of-concept application, the obtained NPSs are used as the electrode material for a supercapacitor. The carbon-sheet-based symmetric cell shows an ultrahigh Brunauer-Emmett-Teller (BET)-area-normalized capacitance of 21.4 µF cm -2 (233 F g -1 ), exceeding other carbon-based supercapacitors. The addition of potassium iodide as redox-active species in a sulfuric acid (supporting electrolyte) leads to the ground-breaking enhancement in the energy density up to 90 Wh kg -1 , which is higher than commercial aqueous rechargeable batteries, maintaining its superior power density. Thus, the new material provides a double profits strategy such as battery-level energy and capacitor-level power density. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stabilized sulfur as cathodes for room temperature sodium-ion batteries.

Energy Technology Data Exchange (ETDEWEB)

Xu, Yunhua [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Liu, Yang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies; Zhu, Yujie [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Zheng, Shiyou [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Liu, Yihang [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Luo, Chao [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Gaskell, Karen [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry; Eichhorn, Bryan [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry; Wang, Chunsheng [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering

2013-05-01

Sodium-sulfur batteries, offering high capacity and low cost, are promising alternative to lithium-ion batteries for large-scale energy storage applications. The conventional sodium-sulfur batteries, operating at a high temperature of 300–350°C in a molten state, could lead to severe safety problems. However, the room temperature sodium-sulfur batteries using common organic liuid electrolytes still face a significant challenge due to the dissolution of intermediate sodium polysulfides. For this study, we developed room temperatue sodium-sulfur batteries using a unique porous carbon/sulfur (C/S) composite cathode, which was synthesized by infusing sulfur vapor into porous carbon sphere particles at a high temperatrure of 600°C. The porous C/S composites delivered a reversible capacity of ~860 mAh/g and retained 83% after 300 cycles. The Coulombic efficiency of as high as 97% was observed over 300 cycles. The superior electrochemical performance is attrbuted to the super sulfur stability as evidenced by its lower sensitivity to probe beam irradiation in TEM, XPS and Raman charaterization and high evaperation temperature in TGA. The results make it promising for large-scale grid energy storage and electric vehicles.

Influence of electrolyte nature on steel membrane hydrogen permeability

International Nuclear Information System (INIS)

Lisovskij, A.P.; Nazarov, A.P.; Mikhajlovskij, Yu.N.

1993-01-01

Effect of electrolyte nature on hydrogen absorption of carbonic steel membrane at its cathode polarization is studied. Electrolyte buffering by anions of subdissociated acids is shown to increase hydrogen flow though the membrane in acid electrolytes. Mechanisms covering dissociation of proton-bearing anion in the electrolyte near-the-electron layer or dissociative adsorption on steel surface are suggested. Effect of proton-bearing bases forming stable complex compounds with iron, is studied. Activation of anode process of iron solution is shown to increase the rate of hydrogen penetration

Acid-base and electrolyte status during normovolemic hemodilution with succinylated gelatin or HES-containing volume replacement solutions in rats.

Directory of Open Access Journals (Sweden)

Johanna K Teloh

Full Text Available BACKGROUND: In the past, several studies have compared different colloidal replacement solutions, whereby the focus was usually on the respective colloid. We therefore systematically studied the influence of the carrier solution's composition of five approved colloidal volume replacement solutions (Gelafundin, Gelafusal, Geloplasma, Voluven and Volulyte on acid-base as well as electrolyte status during and following acute severe normovolemic hemodilution. The solutions differed in the colloid used (succinylated gelatin vs. HES and in the presence and concentration of metabolizable anions as well as in their electrolyte composition. METHODS: Anesthetized Wistar rats were subjected to a stepwise normovolemic hemodilution with one of the solutions until a final hematocrit of 10%. Subsequent to dilution (162 min, animals were observed for an additional period (150 min. During dilution and observation time blood gas analyses were performed eight times in total. Additionally, in the Voluven and Volulyte groups as well as in 6 Gelafundin animals, electrolyte concentrations, glucose, pH and succinylated gelatin were measured in urine and histopathological evaluation of the kidney was performed. RESULTS: All animals survived without any indications of injury. Although the employed solutions differed in their respective composition, comparable results in all plasma acid-base and electrolyte parameters studied were obtained. Plasma pH increased from approximately 7.28 to 7.39, the plasma K(+ concentration decreased from circa 5.20 mM to 4.80-3.90 mM and the plasma Cl(- concentration rose from approximately 105 mM to 111-120 mM. Urinary analysis revealed increased excretion of K(+, H(+ and Cl(-. CONCLUSIONS: The present data suggest that the carrier solution's composition with regard to metabolizable anions as well as K(+, Ca(2+ only has a minor impact on acid-base and electrolyte status after application of succinylated gelatin or HES-containing colloidal

The Origin of Sulfur Tolerance in Supported Platinum Catalysts: The Relationship between Structural and Catalytic Properties in Acidic and Alkaline Pt/LTL.

NARCIS (Netherlands)

Koningsberger, D.C.; Miller, J.T.

1996-01-01

The reactivity, structure, and sulfur tolerance is compared for platinum supported on acidic and alkaline LTL zeolite. In the absence of sulfur, EXAFS spectroscopy indicates that small metallic platinum particles of approximately 6 to 14 atoms/cluster are present. The TOF for neopentane

Sulfur amino acid deficiency upregulates intestinal methionine cycle activity and suppresses epithelial growth in neonatal pigs.

Science.gov (United States)

We recently showed that the developing gut is a significant site of methionine transmethylation to homocysteine and transsulfuration to cysteine. We hypothesized that sulfur amino acid (SAA) deficiency would preferentially reduce mucosal growth and antioxidant function in neonatal pigs. Neonatal pi...

Developing porous carbon with dihydrogen phosphate groups as sulfur host for high performance lithium sulfur batteries

Science.gov (United States)

Cui, Yanhui; Zhang, Qi; Wu, Junwei; Liang, Xiao; Baker, Andrew P.; Qu, Deyang; Zhang, Hui; Zhang, Huayu; Zhang, Xinhe

2018-02-01

Carbon matrix (CM) derived from biomass is low cost and easily mass produced, showing great potential as sulfur host for lithium sulfur batteries. In this paper we report on a dihydrogen phosphate modified CM (PCM-650) prepared from luffa sponge (luffa acutangula) by phosphoric acid treatment. The phosphoric acid not only increases the surface area of the PCM-650, but also introduces dihydrogen phosphate onto PCM-650 (2.28 at% P). Sulfur impregnated (63.6 wt%) PCM-650/S, in comparison with samples with less dihydrogen phosphate LPCM-650/S, shows a significant performance improvement. XPS analysis is conducted for sulfur at different stages, including sulfur (undischarged), polysulfides (discharge to 2.1 V) and short chain sulfides (discharge to 1.7 V). The results consistently show chemical shifts for S2p in PCM-650, suggesting an enhanced adsorption effect. Furthermore, density functional theory (DFT) calculations is used to clarify the molecular binding: carbon/sulfur (0.86 eV), carbon/Li2S (0.3 eV), CH3-O-PO3H2/sulfur (1.24 eV), and CH3-O-PO3H2/Li2S (1.81 eV). It shows that dihydrogen phosphate group can significantly enhance the binding with sulfur and sulfide, consistent with XPS results. Consequently a CM functionalised with dihydrogen phosphate shows great potential as the sulfur host in a Li-S battery.

A sulfur–microporous carbon composite positive electrode for lithium/sulfur and silicon/sulfur rechargeble batteries

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Takuya Takahashi

2015-12-01

Full Text Available Sulfur is an advantageous material as a promising next-generation positive electrode material for high-energy lithium batteries due to a high theoretical capacity of 1672 mA h g−1 although its discharge potential is somewhat modest: ca. 2 V vs Li/Li+. However, a sulfur positive electrode has some crucial problems for practical use, which are mainly attributed to the dissolution of its intermediate products in charge–discharge processes. In order to resolve the dissolution problem of lithium polysulfide, we attempted to synthesize a sulfur–microporous activated carbon (AC composite positive electrode. Moreover, we have systematically researched the battery performance of sulfur–microporous AC positive electrode with variations of electrolytes as well as negative electrodes, and found its promising positive electrode performance for a next-generation rechargeable battery.

Industrial tests of a new technology for sulfuric acid alkylation of isobutane by olefines

Energy Technology Data Exchange (ETDEWEB)

Tarakanov, V.S.; Karamyshev, M.S.; Khadzhiyev, S.N.; Mel' man, A.Z.

1971-01-01

A complex of elements of a new technology for sulfuric acid alkylation of isobutane by alkenes with the use of a KSG-2 reactor and an acetic settler of a new design is realized as a result of the joint work of the Novo-Yaroslav oil refinery, GrozNII, VNIIOINeft and VNIINeftemash in an alkylation installation.

Sulfur amino acids metabolism in magnesium deficient rats

Energy Technology Data Exchange (ETDEWEB)

Tojo, H.; Kosokawa, Y.; Yamaguchi, K.

1984-01-01

Effect of magnesium (Mg) deficiency on sulfur amino acid metabolism was investigated in rats. Young male rats were fed on the diet containing either 2.26 (deficient rats) or 63.18 mg Mg/100g diet (control and low protein rats) for 2 weeks. A remarkable decrease of body weight gain, serum Mg contents and a slight decreases in the hematological parameters such as Hb, Ht and RBC was observed, while the hepatic Mg and Ca was not significantly changed. Erythema and cramps were observed 5 days after feeding on the Mg-depleted diet. The hepatic glutathione and cysteine contents increased in Mg-deficient rats. However, no significant change of cysteine dioxygenase (CDO) activity and taurine content in Mg-deficient rat liver was observed. These results suggest that Mg deficiency affects the utilization and biosynthesis of hepatic glutathione but not the cysteine catabolism.

Influence of solvent on the poly (acrylic acid)-oligo-(ethylene glycol) polymer gel electrolyte and the performance of quasi-solid-state dye-sensitized solar cells

International Nuclear Information System (INIS)

Wu, Jihuai; Lan, Zhang; Lin, Jianming; Huang, Miaoliang; Hao, Shancun; Fang, Leqing

2007-01-01

The influence of solvents on the property of poly (acrylic acid)-oligo-(ethylene glycol) polymer gel electrolyte and photovoltaic performance of quasi-solid-state dye-sensitized solar cells (DSSCs) were investigated. Solvents or mixed solvents with large donor number enhance the liquid electrolyte absorbency, which further influences the ionic conductivity of polymer gel electrolyte. A polymer gel electrolyte with ionic conductivity of 4.45 mS cm -1 was obtained by using poly (acrylic acid)-oligo-(ethylene glycol) as polymer matrix, and absorbing 30 vol.% N-methyl pyrrolidone and 70 vol.% γ-butyrolactone with 0.5 M NaI and 0.05 M I 2 . By using this polymer gel electrolyte coupling with 0.4 M pyridine additive, a quasi-solid-state dye-sensitized solar cell with conversion efficiency of 4.74% was obtained under irradiation of 100 mW cm -2 (AM 1.5)

A Comparative Study of the Addition Effect of Diopside and Silica Sulfuric Acid Nanoparticles on Mechanical Properties of Glass Ionomer Cements

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M. Rezazadeh

2016-09-01

Full Text Available The aim of the present study is to study the effects of adding  diopside (CaMgSi2O6 as well as silica sulfuric acid nanoparticles to ceramic part of glass ionomer cement (GIC in order to improve its mechanical properties. To do this, firstly, diopside (DIO nanoparticles with chemical formula of CaMgSi2O6 were synthesized using sol-gel process and then, the structural and morphological properties of synthesized diopside nanoparticles were investigated. The results of scanning electron microscopy (SEM and particle size analyzing (PSA confirmed that synthesized diopside are nanoparticles and agglomerated. Besides, the result of X-ray diffraction (XRD analyses approved the purity of diopside nanoparticles compounds. Silica sulfuric acid (SSA nanoparticles are also prepared by chemical modification of silica nanoparticles by means of chlorosulfonic acid. Fourier transform infrared spectroscopy (FTIR technique was used to find about the presence of the (SO3H groups on the surface of silica sulfuric acid nanoparticles. Furthermore, various amounts (0.1, 3 and 5 wt.% of diopside and silica sulfuric acid nanoparticles were added to the ceramic part of GIC (Fuji II GIC commercial type to produce glass ionomer cement nanocomposites. The mechanical properties of the produced nanocomposites were measured using the compressive strength, three-point flexural strength and diametral tensile strength methods. Fourier transform infrared spectroscopy technique confirmed the presence of the (SO3H groups on the surface of silica nanoparticles. The compressive strength, three-point flexural strength and diametral tensile strength were 42.5, 15.4 and 6 MPa, respectively, without addition. Although adding 1% silica solfonic acid improved nanocomposite mchanical properties by almost 122%, but maximum increase in nanocomposite mechanical properties was observed in the nanocomposites with 3% diposid, in which 160% increase was seen in the mechanical properties.

Effect of Digestible Protein and Sulfur Amino Acids in Starter Diet on Performance and Small Intestinal (Jejunum Morphology of Broilers

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Avisa Akhavan khaleghi

2016-04-01

Full Text Available Introduction Protein is an essential constituent of all tissues of animal body and has major effect on growth performance of the bird. A better understanding of the nutritional requirements of amino acids allows a more precise nutrition, offering the possibility for the formulator to optimize the requirement of at least minimum levels of crude protein by essential amino acids requirements, generating better result and lower costs for the producer. Methionine + Cystine (total sulfur amino acid = TSSA perform a number of functions in enzyme reactions and protein synthesis. Methionine is an essential amino acid for poultry and has an important role as a precursor of Cystine. Methionine is usually the first limiting amino acid in most of the practical diets for broiler chicken. The efficiency of utilization of dietary nutrients partly depends on the development of the gastro intestinal tract. Material and methods A 2×3 factorial arrangement in a CRD experiment was conducted to study the effect of digestible protein (DP and sulfur amino acids (DSAA during the starter period on performance and small intestinal (jejunum villous morphology. A total number of 300 day-old Ross 308 male broiler chicks were randomly distributed to 30 groups with 10 chicks each. Treatments consisted of two dietary levels of DP (19.5 and 21.5% and three dietary levels of DSAA (0.94, 1.02 and 1.1% that were fed for 10 days. For Each group and treatment, Feed Intake (FI, Weight Gain (WG and Feed Conversion Ratio (FCR were calculated and all the data were statistically analyzed by the SAS software. Results and Discussions The effects of different levels of protein and digestible sulfur amino acids on the mean feed intake, feed conversion ratio and daily weight gain are shown in the Table 3. Increase in the percentage of digestible sulfur amino acids, increased the levels of feed intake and feed conversion ratio in the starter period but, had no effect on the WG. Adding the DSAA

Sulfur turnover and emissions during storage of cattle slurry

DEFF Research Database (Denmark)

Eriksen, Jørgen; Andersen, Astrid J; Poulsen, Henrik Vestergaard

2012-01-01

Slurry acidification using sulfuric acid reduces ammonia emissions but also affects sulfur (S) cycling. Emission of sulfur is a source of malodor and reduces the sulfur fertilizer value of the slurry. We investigated the effect of sulfate and methionine amendments, alone or in combination...

Preparation and characterization of silver loaded montmorillonite modified with sulfur amino acid

Energy Technology Data Exchange (ETDEWEB)

Li, Tian, E-mail: phdlitian@163.com; Lin, Oulian; Lu, Zhiyuan; He, Liuimei; Wang, Xiaosheng

2014-06-01

The Na{sup +} montmorillonite (MMT) was modified with sulfur containing amino acid (L-cystine, L-cysteine or L-methionine) and characterized by energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectrum (FT-IR). The results showed the modification was smooth and the surface condition of MMT was changed with sulfur containing groups. Then silver was loaded on the modified MMTs via ion-exchange reaction under microwave irradiation, the spectra of X-ray photoelectron spectroscopy (XPS), EDS and FT-IR confirmed the successful loading of massive silver and the strong interaction between sulfur and silver, the silver loaded L-cystine modified MMT (Ag@AA-MMT-3) with a silver content of 10.93 wt% was the highest of all. Further more, the Ag@AA-MMT-3 was under the irradiation of a UV lamp to turn silver ions to silver nano particles (Ag NPs). The XPS, specific surface area (SSA), transmission electron microscopy (TEM), XRD patterns and UV–vis spectra proved the existence of uniform nano scaled metallic Ag NPs. By contrast, the UV irradiated Ag@AA-MMT-3 (Ag@AA-MMT-UV) showed a much better slow release property than Ag@AA-MMT-3 or Ag@MMT. The Ag@AA-MMT-UV showing a large inhibition zone and high inhibition ratio presented very good antibacterial property.

Tantalum oxide-based compounds as new non-noble cathodes for polymer electrolyte fuel cell

International Nuclear Information System (INIS)

Ishihara, Akimitsu; Tamura, Motoko; Matsuzawa, Koichi; Mitsushima, Shigenori; Ota, Ken-ichiro

2010-01-01

Tantalum oxide-based compounds were examined as new non-noble cathodes for polymer electrolyte fuel cell. Tantalum carbonitride powder was partially oxidized under a trace amount of oxygen gas at 900 o C for 4 or 8 h. Onset potential for oxygen reduction reaction (ORR) of the specimen heat-treated for 8 h was 0.94 V vs. reversible hydrogen electrode in 0.1 mol dm -3 sulfuric acid at 30 o C. The partial oxidation of tantalum carboniride was effective to enhance the catalytic activity for the ORR. The partially oxidized specimen with highest catalytic activity had ca. 5.25 eV of ionization potential, indicating that there was most suitable strength of the interaction of oxygen and tantalum on the catalyst surface.

Process and device for liquid organic waste processing by sulfuric mineralization

International Nuclear Information System (INIS)

Aspart, A.; Gillet, B.; Lours, S.; Guillaume, B.

1990-01-01

In a chemical reactor containing sulfuric acid are introduced the liquid waste and nitric acid at a controlled flow rate for carbonization of the waste and oxidation of carbon on sulfur dioxide, formed during carbonization, regenerating simultaneously sulfuric acid. Optical density of the liquid is monitored to stop liquid waste feeding above a set-point. The liquid waste can be an organic solvent such as TBP [fr

Development of novel processes for Cu concentrates without producing sulfuric acid; Hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Awakura, Y; Hirato, T [Kyoto University, Kyoto (Japan)

1997-02-01

Studies are conducted to develop a new wet method for copper concentrates to replace the conventional dry smelting method for the settlement of problems involving the processing of impurities for environmental protection. A specimen of pyrites polycrystals is subjected to leaching at 80 {degree}C in a strongly acidic cupric solution. Findings are that the element sulfur generated in this process does not impede leaching and only approximately 4% of the sulfur is oxidized into sulfur ions; that the presence of more than 2g/liter of bromide ions produced during bromine-aid leaching of gold changes the structure of sulfur for the inhibition of leaching; that circulation of a bromine-containing leaching liquid is not desired since even a small amount of approximately 0.02mol/liter inhibits the leaching rate. Controlled potential electrolysis is performed for the anode in an acid solution containing CuCl, NaCl, and NaBr, for the observation of oxidation/reduction potentials predicted by Nernst`s equation. It is then disclosed that bromine is more effective than chlorine in gold leaching and that the solution potential during leaching agent regeneration enables the monitoring of solution constitution. 2 refs.

Sulfur amino acids and alanine on pyrite (100) by X-ray photoemission spectroscopy: Surface or molecular role?

Energy Technology Data Exchange (ETDEWEB)

Sanchez-Arenillas, M.; Galvez-Martinez, S.; Mateo-Marti, E., E-mail: mateome@cab.inta-csic.es

2017-08-31

Highlights: • Surface annealing pretreatment on pyrite surfaces can select molecular adsorption. • Enriched monosulfide species on pyrite (100) surface favors NH{sub 2} adsorption form. • Enriching disulfide species on pyrite (100) surface promotes NH{sub 3}{sup +} adsorption form. • Unique structure of each aminoacid provides a particular fingerprint in the process. • Spectroscopy evidence, pretreatment surface processes drives molecular adsorption. - Abstract: This paper describes the first successful adsorption of the cysteine, cystine, methionine and alanine amino acids on the pyrite (100) surface under ultra-high vacuum conditions with crucial chemical adsorption parameters driving the process. We have demonstrated by X-ray photoemission spectroscopy (XPS) that the surface pretreatment annealing process on pyrite surfaces is a critical parameter driving surface reactivity. The presence of enriched monosulfide species on the pyrite (100) surface favours the amino acid NH{sub 2} chemical form, whereas a longer annealing surface pretreatment of over 3 h repairs the sulfur vacancies in the pyrite, enriching disulfide species on the pyrite surface, which promotes NH{sub 3}{sup +} adsorption due to the sulfur vacancies in the pyrite being replaced by sulfur atom dimers (S{sub 2}{sup 2−}) on the surface. Furthermore, even if the surface chemistry (monosulfide or disulfide species enrichment) is the main factor promoting a partial conversion from NH{sub 2} to NH{sub 3}{sup +} species, the unique chemical structure of each amino acid provides a particular fingerprint in the process.

The buffer effect in neutral electrolyte supercapacitors

DEFF Research Database (Denmark)

Thrane Vindt, Steffen; Skou, Eivind M.

2016-01-01

The observation that double-layer capacitors based on neutral aqueous electrolytes can have significantly wider usable potential windows than those based on acidic or alkaline electrolytes is studied. This effect is explained by a local pH change taking place at the electrode surfaces, leading...... potassium nitrate as the electrolyte and potassium phosphates as the buffer system....

Titania nanotube powders obtained by rapid breakdown anodization in perchloric acid electrolytes

International Nuclear Information System (INIS)

Ali, Saima; Hannula, Simo-Pekka

2017-01-01

Titania nanotube (TNT) powders are prepared by rapid break down anodization (RBA) in a 0.1 M perchloric acid (HClO 4 ) solution (Process 1), and ethylene glycol (EG) mixture with HClO 4 and water (Process 2). A study of the as-prepared and calcined TNT powders obtained by both processes is implemented to evaluate and compare the morphology, crystal structure, specific surface area, and the composition of the nanotubes. Longer TNTs are formed in Process 1, while comparatively larger pore diameter and wall thickness are obtained for the nanotubes prepared by Process 2. The TNTs obtained by Process 1 are converted to nanorods at 350 °C, while nanotubes obtained by Process 2 preserve tubular morphology till 350 °C. In addition, the TNTs prepared by an aqueous electrolyte have a crystalline structure, whereas the TNTs obtained by Process 2 are amorphous. Samples calcined till 450 °C have XRD peaks from the anatase phase, while the rutile phase appears at 550 °C for the TNTs prepared by both processes. The Raman spectra also show clear anatase peaks for all samples except the as-prepared sample obtained by Process 2, thus supporting the XRD findings. FTIR spectra reveal the presence of O-H groups in the structure for the TNTs obtained by both processes. However, the presence is less prominent for annealed samples. Additionally, TNTs obtained by Process 2 have a carbonaceous impurity present in the structure attributed to the electrolyte used in that process. While a negligible weight loss is typical for TNTs prepared from aqueous electrolytes, a weight loss of 38.6% in the temperature range of 25–600 °C is found for TNTs prepared in EG electrolyte (Process 2). A large specific surface area of 179.2 m 2 g −1 is obtained for TNTs prepared by Process 1, whereas Process 2 produces nanotubes with a lower specific surface area. The difference appears to correspond to the dimensions of the nanotubes obtained by the two processes. - Graphical abstract: Titania nanotube

Non-aqueous electrolytes for lithium ion batteries

Science.gov (United States)

Chen, Zonghai; Amine, Khalil

2015-11-12

The present invention is generally related to electrolytes containing anion receptor additives to enhance the power capability of lithium-ion batteries. The anion receptor of the present invention is a Lewis acid that can help to dissolve LiF in the passivation films of lithium-ion batteries. Accordingly, one aspect the invention provides electrolytes comprising a lithium salt; a polar aprotic solvent; and an anion receptor additive; and wherein the electrolyte solution is substantially non-aqueous. Further there are provided electrochemical devices employing the electrolyte and methods of making the electrolyte.

Macroporous Activated Carbon Derived from Rapeseed Shell for Lithium–Sulfur Batteries

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Mingbo Zheng

2017-10-01

Full Text Available Lithium–sulfur batteries have drawn considerable attention because of their extremely high energy density. Activated carbon (AC is an ideal matrix for sulfur because of its high specific surface area, large pore volume, small-size nanopores, and simple preparation. In this work, through KOH activation, AC materials with different porous structure parameters were prepared using waste rapeseed shells as precursors. Effects of KOH amount, activated temperature, and activated time on pore structure parameters of ACs were studied. AC sample with optimal pore structure parameters was investigated as sulfur host materials. Applied in lithium–sulfur batteries, the AC/S composite (60 wt % sulfur exhibited a high specific capacity of 1065 mAh g−1 at 200 mA g−1 and a good capacity retention of 49% after 1000 cycles at 1600 mA g−1. The key factor for good cycling stability involves the restraining effect of small-sized nanopores of the AC framework on the diffusion of polysulfides to bulk electrolyte and the loss of the active material sulfur. Results demonstrated that AC materials derived from rapeseed shells are promising materials for sulfur loading.

Effect of air pollution by copper, sulfuric acid and fertilizer factories on plants at Harjavalta, West Finland

Energy Technology Data Exchange (ETDEWEB)

Laaksovirta, K; Silvola, J

1975-01-01

The most sensitive index of air pollution proved to be the sulfur content of needles of the Scots pine; the normal contents were reached at a distance of 20-30 km from the factories. The industrial site lies in a lichen desert (8.8 km/sup 2/), outside which is a transitional zone (52 km/sup 2/). The pine damage area coincides almost exactly with the lichen desert. The order of susceptibility of the dwarf shrubs studied proved to be: Calluna vulgaris (least tolerant), Empetrum nigrum, Vaccinium vitis-idaea and Arctostaphylos uva-ursi. The acidity of the soil had not changed very much. The acidity of the pine bark had decreased and the sulfur and phosphorus contents of the bark had risen between the factories and the limit of the lichen desert, because of fertilizer dust. 25 references, 9 figures, 1 table.

Titanium leaching from red mud by diluted sulfuric acid at atmospheric pressure

International Nuclear Information System (INIS)

Agatzini-Leonardou, S.; Oustadakis, P.; Tsakiridis, P.E.; Markopoulos, Ch.

2008-01-01

Laboratory-scale research has focused on the recovery of titanium from red mud, which is obtained from bauxite during the Bayer process for alumina production. The leaching process is based on the extraction of this element with diluted sulfuric acid from red mud under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The titanium recovery efficiency on the basis of red mud weight reached 64.5%. The characterization of the initial red mud, as well as this of the leached residues was carried out by X-ray diffraction, TG-DTA and scanning electron microscopy

Contact Resistance of Tantalum Coatings in Fuel Cells and Electrolyzers using Acidic Electrolytes at Elevated Temperatures

DEFF Research Database (Denmark)

Jensen, Annemette Hindhede; Christensen, Erik; Barner, Jens H. Von

2014-01-01

stainless steel were found to be far below the US Department of Energy target value of 10mcm2. The good contact resistance of tantalum was demonstrated by simulating high temperature polymer electrolyte membrane electrolysis conditions by anodization performed in 85% phosphoric acid at 130◦C, followed...

Physiology and application of sulfur-reducing microorganisms from acidic environments

NARCIS (Netherlands)

Florentino, Anna Patrícya

2017-01-01

Sulfur cycle is one of the main geochemical cycles on Earth. Oxidation and reduction reactions of sulfur are mostly biotic and performed by microorganisms. In anaerobic conditions – marine and some freshwater systems, dissimilatory sulfur- and sulfate-reducing bacteria and archaea are key players

System for processing ion exchange resin regeneration waste liquid in atomic power plant

International Nuclear Information System (INIS)

Onaka, Noriyuki; Tanno, Kazuo; Shoji, Saburo.

1976-01-01

Object: To reduce the quantity of radioactive waste to be solidified by recovering and repeatedly using sulfuric acid and sodium hydroxide which constitute the ion exchange resin regeneration waste liquid. Structure: Cation exchange resin regeneration waste liquid is supplied to an anion exchange film electrolytic dialyzer for recovering sulfuric acid through separation from impurity cations, while at the same time anion exchange resin regeneration waste liquid is supplied to a cation exchange film electrolytic dialyzer for recovering sodium hydroxide through separation from impurity anions. The sulfuric acid and sodium hydroxide thus recovered are condensed by a thermal condenser and then, after density adjustment, repeatedly used for the regeneration of the ion exchange resin. (Aizawa, K.)

Experimental particle formation rates spanning tropospheric sulfuric acid and ammonia abundances, ion production rates, and temperatures

CERN Document Server

Kürten, Andreas; Almeida, Joao; Kupiainen-Määttä, Oona; Dunne, Eimear M.; Duplissy, Jonathan; Williamson, Christina; Barmet, Peter; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M.; Flagan, Richard C.; Franchin, Alessandro; Gordon, Hamish; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Ickes, Luisa; Jokinen, Tuija; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Onnela, Antti; Ortega, Ismael K.; Petäjä, Tuukka; Praplan, Arnaud P.; Riccobono, Francesco; Rissanen, Matti P.; Rondo, Linda; Schnitzhofer, Ralf; Schobesberger, Siegfried; Smith, James N.; Steiner, Gerhard; Stozhkov, Yuri; Tomé, António; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Wagner, Paul E.; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Ken; Kulmala, Markku; Curtius, Joachim

2016-01-01

Binary nucleation of sulfuric acid and water as well as ternary nucleation involving ammonia arethought to be the dominant processes responsible for new particle formation (NPF) in the cold temperaturesof the middle and upper troposphere. Ions are also thought to be important for particle nucleation inthese regions. However, global models presently lack experimentally measured NPF rates under controlledlaboratory conditions and so at present must rely on theoretical or empirical parameterizations. Here withdata obtained in the European Organization for Nuclear Research CLOUD (Cosmics Leaving OUtdoor Droplets)chamber, we present the first experimental survey of NPF rates spanning free tropospheric conditions. Theconditions during nucleation cover a temperature range from 208 to 298 K, sulfuric acid concentrationsbet ween 5 × 105and 1 × 109cm3, and ammonia mixing ratios from zero added ammonia, i.e., nominally purebinary, to a maximum of ~1400 parts per trillion by volume (pptv). We performed nucleation s...

Sulfur-doped porous reduced graphene oxide hollow nanosphere frameworks as metal-free electrocatalysts for oxygen reduction reaction and as supercapacitor electrode materials.

Science.gov (United States)

Chen, Xi'an; Chen, Xiaohua; Xu, Xin; Yang, Zhi; Liu, Zheng; Zhang, Lijie; Xu, Xiangju; Chen, Ying; Huang, Shaoming

2014-11-21

Chemical doping with foreign atoms is an effective approach to significantly enhance the electrochemical performance of the carbon materials. Herein, sulfur-doped three-dimensional (3D) porous reduced graphene oxide (RGO) hollow nanosphere frameworks (S-PGHS) are fabricated by directly annealing graphene oxide (GO)-encapsulated amino-modified SiO2 nanoparticles with dibenzyl disulfide (DBDS), followed by hydrofluoric acid etching. The XPS and Raman spectra confirmed that sulfur atoms were successfully introduced into the PGHS framework via covalent bonds. The as-prepared S-PGHS has been demonstrated to be an efficient metal-free electrocatalyst for oxygen reduction reaction (ORR) with the activity comparable to that of commercial Pt/C (40%) and much better methanol tolerance and durability, and to be a supercapacitor electrode material with a high specific capacitance of 343 F g(-1), good rate capability and excellent cycling stability in aqueous electrolytes. The impressive performance for ORR and supercapacitors is believed to be due to the synergistic effect caused by sulfur-doping enhancing the electrochemical activity and 3D porous hollow nanosphere framework structures facilitating ion diffusion and electronic transfer.

Application of various types of alumina and nano--alumina sulfuric acid in the synthesis of α-aminonitriles derivatives: comparative study

Directory of Open Access Journals (Sweden)

A. Teimouri

2014-09-01

Full Text Available An efficient and green protocol for the synthesis of α-aminonitrile derivatives by one-pot reaction of different aldehydes with amines and trimethylsilyl cyanide has been developed using natural alumina, alumina sulfuric acid (ASA, nano-g-alumina, nano-g-alumina sulfuric acid (nano-g-ASA under microwave irradiation and solvent-free conditions. The advantages of methods are short reaction times, high yields, milder conditions and easy work up. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency. DOI: http://dx.doi.org/10.4314/bcse.v28i3.13

Rapid evaluation of the electrooxidation of fuel compounds with a multiple-electrode setup for direct polymer electrolyte fuel cells

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, Naoko; Siroma, Zyun; Ioroi, Tsutomu; Yasuda, Kazuaki [Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

2007-02-10

Electrochemical oxidation of fuel compounds in acidic media was examined on eight electrodes (Pt, Ru, PtRu, Rh, Ir, Pd, Au, and glassy carbon) simultaneously by multiple cyclic voltammetry (CV) with an electrochemical cell equipped with an eight-electrode configuration. Direct-type polymer electrolyte fuel cells (PEFCs), in which aqueous solutions of the fuel compounds are directly supplied to the anode, were also evaluated. The performances of direct PEFCs with various anode catalysts could be roughly estimated from the results obtained with multiple CV. This multiple evaluation may be useful for identifying novel fuels or electrocatalysts. Methanol, ethanol, ethylene glycol, 2-propanol, and D-glucose were oxidized selectively on Pt or PtRu, as reported previously. However, several compounds that are often used as reducing agents show electrochemical oxidation with unique characteristics. Large current was obtained for the oxidation of formic acid, hypophosphorous acid, and phosphorous acid on a Pd electrode. L-Ascorbic acid and sulfurous acid were oxidized on all of the electrodes used in the present study. (author)

Effect of simulated sulfuric acid rain on yield, growth and foliar injury of several crops

Energy Technology Data Exchange (ETDEWEB)

Lee, J J; Neely, G E; Perrigan, S C; Grothaus, L C

1981-01-01

This study was designed to reveal patterns of response of major United States crops to sulfuric acid rain. Potted plants were grown in field chambers and exposed to simulated sulfuric acid rain (pH 3.0, 3.5 or 4.0) or to a control rain (pH 5.6). At harvest, the weights of the marketable portion, total aboveground portion and roots were determined for 28 crops. Of these, marketable yield production was inhibited for 5 crops (radish, beet, carrot, mustard greens, broccoli), stimulated for 6 crops (tomato, green pepper, strawberry, alfalfa, orchardgrass, timothy), and ambiguously affected for 1 crop (potato). In addition, stem and leaf production of sweet corn was stimulated. Visible injury of tomatoes might have decreased their marketabiity. No statistically significant effects on yield were observed for the other 15 crops. The results suggest that the likelihood of yield being affected by acid depends on the part of the plant utilized, as well as on species. Effects on the aboveground portion of crops and on roots are also presented. Plants were regularly examined for foliar injury associated with acid rain. Of the 35 cultivars examined, the foliage of 31 was injured at pH 3.0, 28 at pH 3.5, and 5 at pH 4.0. Foliar injury was not generally related to effects on yield. However, foliar injury of Swiss chard, mustard greens and spinach was severe enough to adversely affect marketability.

Yields of cotton and other crops as affected by applications of sulfuric acid in irrigation water

Energy Technology Data Exchange (ETDEWEB)

Christensen, P.D.; Lyerly, P.J.

1954-01-01

Effects of sulfuric acid on crop yields and on some physical and chemical properties of a calcareous soil were investigated in a field experiment from 1947 through 1952. On cotton plots, the treatments consisted of applications of irrigation water containing no acid (pH 8.3), water acidified to pH 6, and water acidified to pH 2.3. Cotton was grown five seasons followed by sesbania the sixth season. A test on alfalfa was established using irrigation water not acidified and water acidifeid to pH 4. Alfalfa was grown for 3 years. The fourth year the alfalfa was plowed under and a crop of corn was raised. Cotton yields on the acid plots relative to the checks became progressively higher (with two exceptions) from one year to the next; however, in only one year (1950) were differences in yield statistically significant. With sesbania following cotton, highly significant yield increases resulted from the high acid treatment. Alfalfa yields on the acid plots became progressively greater relative to the non-acid plots, but yield differences were not significant. In cotton leaves, the acid treatments resulted in increased uptake of magnesium, sulfur, and phosphorus, but the increases were probably not significant. Uptake of sodium, potassium, calcium, manganese, and iron were not appreciably affected. In sesbania, the acid treatments did not significantly alter the uptake of any of the plant nutrients determined. There was some indication, however, that the uptake of sodium and iron was reduced by the acidification. The results of this study support the view that soil acidification on calcareous soils may improve the soil physical conditions and result in increased yields, particularly in some crops. The application of acid in the irrigation water did not prove to be economically feasible. 12 references, 1 figure, 7 tables.

Mass transfer during sulfuric acid concentration by evaporation into the air flow

Directory of Open Access Journals (Sweden)

V. K. Lukashov

2016-12-01

Full Text Available This article shows the results of the study of mass transfer under periodic concentration of sulfuric acid by evaporation inthe gas flow, neutral with respect to the components of acid.Used mathematical model for mass transferbases on the proposed simplified physical representations.This model has allowed to construct an algorithm for calculation the coefficient of mass transfer from the liquid phase into the gas flow. The algorithm uses the experimental data of change the amount of acid and concentration of the water taken from the laboratory tests. Time-based Nusselt diffusion criterion represent the results of the study at different modes of the evaporation process.It has been found that the character of the influence of temperature and initial acid concentration on Nusselt diffusion criterion depends on the variation range of the mass fraction of water in the acid.It is shown that these dependences are well approximated by an exponential function from the dimensionless parameters of the process. This allows usingthem for calculation the mass transfer coefficient into the gas phase in a batch process of concentrating in the range of investigated modes.

Oxidation of alginate and pectate biopolymers by cerium(IV) in perchloric and sulfuric acid solutions: A comparative kinetic and mechanistic study.

Science.gov (United States)

Fawzy, Ahmed

2016-03-15

The kinetics of oxidation of alginate (Alg) and pectate (Pec) carbohydrate biopolymers was studied by spectrophotometry in aqueous perchloric and sulfuric acid solutions at fixed ionic strengths and temperature. In both acids, the reactions showed a first order dependence on [Ce(IV)], whereas the orders with respect to biopolymer concentrations are less than unity. In perchloric acid, the reactions exhibited less than unit orders with respect to [H(+)] whereas those proceeded in sulfuric acid showed negative fractional-first order dependences on [H(+)]. The effect of ionic strength and dielectric constant was studied. Probable mechanistic schemes for oxidation reactions were proposed. In both acids, the final oxidation products were characterized as mono-keto derivatives of both biopolymers. The activation parameters with respect to the slow step of the mechanisms were computed and discussed. The rate laws were derived and the reaction constants involved in the different steps of the mechanisms were calculated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water

International Nuclear Information System (INIS)

Nakajima, Hayato; Imai, Yoshiyuki; Kasahara, Seiji; Kubo, Shinji; Onuki, Kaoru

2007-01-01

Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water, which is a unit reaction in the IS process for thermochemical hydrogen production, was studied experimentally at 323 K under iodine saturation. Quasi-equilibrium state was observed in the presence of sulfur dioxide gas at constant pressure. The composition of the poly-hydriodic acid solution formed was discussed assuming an ideal desulfurization by the reverse reaction of the Bunsen reaction. The value of HI/(HI+H 2 O) of the desulfurized solution was large at high sulfur dioxide pressure and reached the maximum of 15.7 ± 0.3 mol%. (author)

Recovery of vanadium (V) from spent catalysts used in sulfuric acid production units by acid or alkaline leaching

International Nuclear Information System (INIS)

Abdulbaki, M.; Stas, J.; Shino, O.; Asaad, K.; Al-Kassemi, H.; Al-Qabani, F.

2008-01-01

The present paper, studies the recovery of vanadium from the spent catalyst by using acidic or alkaline leaching technique. The optimal conditions of spent catalyst leaching have been studied. It has been shown that 20%(w/w) of sulfuric acid is the most suitable for leaching process at 70 Centigrade. The precipitation of vanadium using some alkaline media (Na 2 CO 3 , (NH 4 )CO 3 and NH 4 OH) has been also studied, it has been shown that ammonium hydroxide was the best at 60 degree, and iron was co-precipitated with vanadium which pollute the obtained red cake. So it is necessary to use liquid-liquid extraction technique for the separation between vanadium and iron and to have iron free red cake. (author)

A novel flow battery: A lead acid battery based on an electrolyte with soluble lead(II). Part IX: Electrode and electrolyte conditioning with hydrogen peroxide

Science.gov (United States)

Collins, John; Li, Xiaohong; Pletcher, Derek; Tangirala, Ravichandra; Stratton-Campbell, Duncan; Walsh, Frank C.; Zhang, Caiping

Extended cycling of a soluble lead acid battery can lead to problems due to an imbalance in the coulombic efficiency leading to deposits of Pb and PbO2 on the electrodes. Periodic addition of hydrogen peroxide to the electrolyte of the soluble lead acid flow battery largely overcomes several operational problems seen during extended cycling, using a 10 cm × 10 cm parallel plate flow cell. It is shown that this treatment greatly extends the number of cycles that can be achieved with a reasonable energy-, voltage-, and charge efficiency of 54-66%, 71%, and 77-91%.

A novel flow battery: A lead acid battery based on an electrolyte with soluble lead(II). Part IX: Electrode and electrolyte conditioning with hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Collins, John; Stratton-Campbell, Duncan [C-Tech Innovation Ltd., Capenhurst, Chester CH1 6EH (United Kingdom); Li, Xiaohong; Tangirala, Ravichandra; Walsh, Frank C.; Zhang, Caiping [Energy Technology Research Group, School of Engineering Sciences, University of Southampton, Highfield, University Road, Southampton SO17 1BJ (United Kingdom); Pletcher, Derek [Electrochemistry and Surface Science Group, School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom)

2010-05-01

Extended cycling of a soluble lead acid battery can lead to problems due to an imbalance in the coulombic efficiency leading to deposits of Pb and PbO2 on the electrodes. Periodic addition of hydrogen peroxide to the electrolyte of the soluble lead acid flow battery largely overcomes several operational problems seen during extended cycling, using a 10 cm x 10 cm parallel plate flow cell. It is shown that this treatment greatly extends the number of cycles that can be achieved with a reasonable energy-, voltage-, and charge efficiency of 54-66%, 71%, and 77-91%. (author)

Electrolytes for lithium ion batteries

Science.gov (United States)

Vaughey, John; Jansen, Andrew N.; Dees, Dennis W.

2014-08-05

A family of electrolytes for use in a lithium ion battery. The genus of electrolytes includes ketone-based solvents, such as, 2,4-dimethyl-3-pentanone; 3,3-dimethyl 2-butanone(pinacolone) and 2-butanone. These solvents can be used in combination with non-Lewis Acid salts, such as Li.sub.2[B.sub.12F.sub.12] and LiBOB.

Uranium manufacturing process employing the electrolytic reduction method

International Nuclear Information System (INIS)

Oda, Yoshio; Kazuhare, Manabu; Morimoto, Takeshi.

1986-01-01

The present invention related to a uranium manufacturing process that employs the electrolytic reduction method, but particularly to a uranium manufacturing process that employs an electrolytic reduction method requiring low voltage. The process, in which uranium is obtained by means of the electrolytic method and with uranyl acid as the raw material, is prior art

Studies on the protein and sulfur amino acid requirements of young bobwhite quail

Science.gov (United States)

Serafin, J.A.

1977-01-01

Four experiments were conducted with purified diets to examine the influence of protein level and to estimate the sulfur amino acid (S.A.A.) requirement of young Bobwhite quail (Colinus virginianus). These studies demonstrated (I) that 26% protein was sufficient for rapid growth when the diet was supplemented with methionine; (2) that diets containing higher levels of protein (29.3% and 31.3%) failed to support satisfactory growth unless they contained supplemental methionine; and (3) that young Bobwhite quail require no more than 1.0% sulfur-containing amino acids for optimal growth and efficiency of feed utilization. A fifth experiment was conducted to examine the protein and S.A.A. requirements of young Bobwhite quail using practical rations and to compare results with those obtained with purified diets. Diets containing 24%, 26% and 28% protein were supplied with and without supplemental methionine in a five week study. Results showed significant growth responses to protein and supplemental methionine. Responses showed that Bobwhite quail require no more than 26% protein for maximum growth and efficiency of feed utilization when the S.A.A. level of the diet was approximately 1.0%. The results were in close agreement with those obtained with purified diets. These findings define more precisely than had been known the quantitative requirements of young Bobwhite quail for protein and for the S.A.A. necessary for optimal growth.

Titania nanotube powders obtained by rapid breakdown anodization in perchloric acid electrolytes

Energy Technology Data Exchange (ETDEWEB)

Ali, Saima, E-mail: saima.ali@aalto.fi; Hannula, Simo-Pekka

2017-05-15

Titania nanotube (TNT) powders are prepared by rapid break down anodization (RBA) in a 0.1 M perchloric acid (HClO{sub 4}) solution (Process 1), and ethylene glycol (EG) mixture with HClO{sub 4} and water (Process 2). A study of the as-prepared and calcined TNT powders obtained by both processes is implemented to evaluate and compare the morphology, crystal structure, specific surface area, and the composition of the nanotubes. Longer TNTs are formed in Process 1, while comparatively larger pore diameter and wall thickness are obtained for the nanotubes prepared by Process 2. The TNTs obtained by Process 1 are converted to nanorods at 350 °C, while nanotubes obtained by Process 2 preserve tubular morphology till 350 °C. In addition, the TNTs prepared by an aqueous electrolyte have a crystalline structure, whereas the TNTs obtained by Process 2 are amorphous. Samples calcined till 450 °C have XRD peaks from the anatase phase, while the rutile phase appears at 550 °C for the TNTs prepared by both processes. The Raman spectra also show clear anatase peaks for all samples except the as-prepared sample obtained by Process 2, thus supporting the XRD findings. FTIR spectra reveal the presence of O-H groups in the structure for the TNTs obtained by both processes. However, the presence is less prominent for annealed samples. Additionally, TNTs obtained by Process 2 have a carbonaceous impurity present in the structure attributed to the electrolyte used in that process. While a negligible weight loss is typical for TNTs prepared from aqueous electrolytes, a weight loss of 38.6% in the temperature range of 25–600 °C is found for TNTs prepared in EG electrolyte (Process 2). A large specific surface area of 179.2 m{sup 2} g{sup −1} is obtained for TNTs prepared by Process 1, whereas Process 2 produces nanotubes with a lower specific surface area. The difference appears to correspond to the dimensions of the nanotubes obtained by the two processes. - Graphical abstract

Damage caused to vegetation by sulfurous and sulfuric acids in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Tatlock, R R; Thomson, R T

1914-05-01

This report, written in 1914, documents injuries to trees and shrubs in the United Kingdom which are attributed to sulfur compounds in air pollutions. Sampling, analytical and experimental procedures are discussed.

Effect of various additives on morphological and structural characteristics of pulse electrodeposited tin coatings from stannous sulfate electrolyte

Energy Technology Data Exchange (ETDEWEB)

Sharma, Ashutosh, E-mail: stannum.ashu@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Das, Karabi [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Fecht, Hans-J. [Institut für Mikro- und Nanomaterialien, Universität Ulm, D-89081 Ulm (Germany); Das, Siddhartha [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

2014-09-30

Graphical abstract: - Highlights: • PEG and thiourea act as grain refiners, and Triton X-100 acts as brightener in bath. • Additives refine the crystallite size and modify the orientation of lattice planes. • Dendritic and nodular growths are reduced when additives are used in combination. - Abstract: The pulse electrodeposited tin coatings are synthesized from an acidic electrolyte (stannous sulfate, SnSO{sub 4}30 g/L and sulfuric acid, H{sub 2}SO{sub 4}—200 g/L) containing various additives (polyethylene glycol (PEG), thiourea and Triton X-100). The effect of the additives on surface morphology, preferred orientation of grains, grain size, and surface roughness has been studied. The final coatings are characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and surface profilometry. In the absence of additives, tin deposition is associated with prominent hydrogen evolution reaction giving rise to rough deposits. Both PEG and thiourea act as grain refiner while Triton X-100 acts as a brightener in the electrolyte. The cathodic polarization on the reduction of the tin (II) ions is more pronounced when a combination of additives is used and further, fine-grained, smooth and shiny electrodeposits of tin are obtained due to a synergistic effect of the adsorbed species.

Growth behavior of anodic oxide formed by aluminum anodizing in glutaric and its derivative acid electrolytes

Science.gov (United States)

Nakajima, Daiki; Kikuchi, Tatsuya; Natsui, Shungo; Suzuki, Ryosuke O.

2014-12-01

The growth behavior of anodic oxide films formed via anodizing in glutaric and its derivative acid solutions was investigated based on the acid dissociation constants of electrolytes. High-purity aluminum foils were anodized in glutaric, ketoglutaric, and acetonedicarboxylic acid solutions under various electrochemical conditions. A thin barrier anodic oxide film grew uniformly on the aluminum substrate by glutaric acid anodizing, and further anodizing caused the film to breakdown due to a high electric field. In contrast, an anodic porous alumina film with a submicrometer-scale cell diameter was successfully formed by ketoglutaric acid anodizing at 293 K. However, the increase and decrease in the temperature of the ketoglutaric acid resulted in non-uniform oxide growth and localized pitting corrosion of the aluminum substrate. An anodic porous alumina film could also be fabricated by acetonedicarboxylic acid anodizing due to the relatively low dissociation constants associated with the acid. Acid dissociation constants are an important factor for the fabrication of anodic porous alumina films.

Method of continuously regenerating decontaminating electrolytic solution

International Nuclear Information System (INIS)

Sasaki, Takashi; Kobayashi, Toshio; Wada, Koichi.

1985-01-01

Purpose: To continuously recover radioactive metal ions from the electrolytic solution used for the electrolytic decontamination of radioactive equipment and increased with the radioactive dose, as well as regenerate the electrolytic solution to a high concentration acid. Method: A liquid in an auxiliary tank is recycled to a cathode chamber containing water of an electro depositing regeneration tank to render pH = 2 by way of a pH controller and a pH electrode. The electrolytic solution in an electrolytic decontaminating tank is introduced by way of an injection pump to an auxiliary tank and, interlocking therewith, a regenerating solution is introduced from a regenerating solution extracting pump by way of a extraction pipeway to an electrolytic decontaminating tank. Meanwhile, electric current is supplied to the electrode to deposit radioactive metal ions dissolved in the cathode chamber on the capturing electrode. While on the other hand, anions are transferred by way of a partition wall to an anode chamber to regenerate the electrolytic solution to high concentration acid solution. While on the other hand, water is supplied by way of an electromagnetic valve interlocking with the level meter to maintain the level meter constant. This can decrease the generation of the liquid wastes and also reduce the amount of the radioactive secondary wastes. (Horiuchi, T.)

Preparation of Activated Carbon from Maize Stems by Sulfuric Acids Activation and Their Application in Copper (II Ion Sorption

Directory of Open Access Journals (Sweden)

Erin Ryantin Gunawan

2010-04-01

Full Text Available Activated carbons were prepared from maize (Zea mays L. stems by sulfuric acids activation or chemical methods. The dry maize stems are usually used as low-value energy resources in many countries, burned in the field, or discarded, which are unfavorable to environment. This motivates the investigation of producing value-added products from the dry maize stems, such as activated carbons, as well as solving some environmental problems. The preparation process consisted of sulfuric acid impregnation at different impregnation ratio followed by carbonization at 250-400 oC for 1-4 h. The results show that the impregnation ratio was 1.25, the optimum activation temperature was 300 oC and the activation time was 1 h. The sorption capacity of the activated carbon was 25.1 mg/g.

Development of once-through hybrid sulfur process for nuclear hydrogen production

International Nuclear Information System (INIS)

Jung, Yong Hun

2010-02-01

Humanity has been facing major energy challenges such as the severe climate change, threat of energy security and global energy shortage especially for the developing world. Particularly, growing awareness of the global warming has led to efforts to develop the sustainable energy technologies for the harmony of the economy, social welfare and environment. Water-splitting nuclear hydrogen production is expected to help to resolve those challenges, when high energy efficiency and low cost for hydrogen production become possible. Once-through Hybrid Sulfur process (Ot-HyS), proposed in this work, produces hydrogen using the same SO 2 Depolarized water Electrolysis (SDE) process found in the original Hybrid Sulfur cycle (HyS) proposed by Westinghouse, which has the sulfuric acid decomposition (SAD) process using high temperature heat source in order to recover sulfur dioxide for the SDE process. But Ot-HyS eliminated this technical hurdle by replacing it with well-established sulfur combustion process to feed sulfur dioxide to the SDE process. Because Ot-HyS has less technical challenges, Ot-HyS is expected to advance the realization of the large-scale nuclear hydrogen production by feeding an initial nuclear hydrogen stock. Most of the elemental sulfur, at present, is supplied by desulfurization process for environmental reasons during the processing of natural gas and petroleum refining and expected to increase significantly. This recovered sulfur will be burned with oxygen in the sulfur combustion process so that produced sulfur dioxide could be supplied to the SDE process to produce hydrogen. Because the sulfur combustion is a highly exothermic reaction releasing 297 kJ/mol of combustion heat resulting in a large temperature rise, efficiency of the Ot-HyS is expected to be high by recovering this great amount of high grade excess heat with nuclear energy. Sulfuric acid, which is a byproduct of the SDE process, could be sent to the neighboring consumers with or even

Effects of vine water status on dimethyl sulfur potential, ammonium, and amino acid contents in Grenache Noir grapes (Vitis vinifera).

Science.gov (United States)

De Royer Dupré, N; Schneider, R; Payan, J C; Salançon, E; Razungles, A

2014-04-02

We studied the effect of vine water status on the dimethyl sulfur potential (DMSP), ammonium, and amino acid contents of the berry during the maturation of Grenache Noir grapes. Water deficit increased the accumulation of amino acids in berries and favored yeast assimilable amino nitrogen. Similarly, ammonium content was higher in berries from vines subjected to moderate water deficit. DMSP content followed the same trend as yeast assimilable amino acid content, with higher concentrations observed in the berries of vines subjected to water deficit. The high DMSP and yeast assimilable nitrogen contents of musts from vines subjected to water deficit resulted in a better preservation of DMSP during winemaking. The wines produced from these musts had a higher DMSP level and would therefore probably have a higher aroma shelf life, because the DMSP determines the rate of release of dimethyl sulfur during wine storage, and this compound enhances fruity notes.

Status of the INERI sulfur-iodine integrated-loop experiment

International Nuclear Information System (INIS)

Pickard, P.; Carles, Ph.; Buckingham, R.; Russ, B.; Besenbruch, G.

2007-01-01

The Sulfur-Iodine (S-I) thermochemical water-splitting cycle has been studied as a potential source of hydrogen on a large scale. Coupled to a nuclear reactor, an S-I hydrogen plant could efficiently produce hydrogen without greenhouse gas emissions. In the S-I cycle, iodine and sulfur dioxide are combined with water to create two immiscible acid phases - a light sulfuric acid phase, and a heavy hydriodic acid phase. The sulfuric acid phase is decomposed at temperatures near 850 C degrees, and the resulting sulfur dioxide is recycled back into the process. The hydriodic acid in the lower phase is separated from excess water and iodine, and is then decomposed into the product hydrogen and iodine. The water and iodine from these steps are also recycled. In an International Nuclear Energy Research Initiative (INERI) project supported by the US DOE Office of Nuclear Energy, Sandia National Labs (SNL) has teamed with Cea in France, and industrial partner General Atomics (GA) to construct and operate a closed-loop device for demonstration of hydrogen production by the S-I process. Previous work in Japan has demonstrated continuous closed-loop operation of the S-I cycle for up to one week using glass components at atmospheric pressure. This work will aim for operation under process conditions expected at the pilot plant-level and beyond pressures up to 20 bar using engineering materials of construction. Staff at Cea is responsible for the acid-generation step, known as the Bunsen reaction. SNL is handling the sulfuric acid decomposition step, and GA is providing equipment for decomposing hydriodic acid into the product hydrogen. All parties are assembling equipment at the GA site in San Diego, California. Operation of the closed-loop device is expected to commence in the second half of calendar year 2007. This paper will summarize project goals, work done to date, current status, and scheduled future work on the INERI S-I Integrated-Loop Experiment. (authors)

Acid-doped Polybenzimidazole Membranes as Electrolyte for Fuel Cells Operating Above 100°C

DEFF Research Database (Denmark)

Qingfeng, Li; Jensen, Jens Oluf; He, Ronhuan

2003-01-01

The technical achievement and challenges for the PEMFC technology based on perfluorosulfonic acid (PFSA) polymer membranes (e.g. Nafion®) are briefly discussed. The newest development in the field is alternative polymer electrolytes for operation above 100°C. As one of the successful approaches...... to high operational temperatures, the development and evaluation of acid doped PBI membranes are reviewed, covering polymer synthesis, membrane casting, acid doping, physiochemical characterization and fuel cell tests. A high temperature PEMFC system operational at up to 200°C is demonstrated with no gas...... humidification and high CO-tolerance up to 10 vol%. This high CO tolerance allows for a direct use of reformed hydrogen without further CO removal, which opens the possibility for an integrated reformer-fuel cell system. The content of this review is to a large extent based on research performed by the authors...

PROPOSAL FOR THE IMPLEMENTATION OF SPRAY DRYING IN THE ACTIVATION PROCESS OF BENTONITE WITH SULFURIC ACID

OpenAIRE

Romero, P.; Otiniano, M.

2014-01-01

The present work propose the replacement of the three stages of the activation process of bentonite with sulfuric acid by the only stage spray drying. El presente trabajo propone reemplazar tres etapas del proceso de activación de la bentonita con ácido sulfúrico por una sola etapa, la del secado por atomización.

Thermal stress analysis of sulfur deactivated solid oxide fuel cells

Science.gov (United States)

Zeng, Shumao; Parbey, Joseph; Yu, Guangsen; Xu, Min; Li, Tingshuai; Andersson, Martin

2018-03-01

Hydrogen sulfide in fuels can deactivate catalyst for solid oxide fuel cells, which has become one of the most critical challenges to stability. The reactions between sulfur and catalyst will cause phase changes, leading to increase in cell polarization and mechanical mismatch. A three-dimensional computational fluid dynamics (CFD) approach based on the finite element method (FEM) is thus used to investigate the polarization, temperature and thermal stress in a sulfur deactivated SOFC by coupling equations for gas-phase species, heat, momentum, ion and electron transport. The results indicate that sulfur in fuels can strongly affect the cell polarization and thermal stresses, which shows a sharp decrease in the vicinity of electrolyte when 10% nickel in the functional layer is poisoned, but they remain almost unchanged even when the poisoned Ni content was increased to 90%. This investigation is helpful to deeply understand the sulfur poisoning effects and also benefit the material design and optimization of electrode structure to enhance cell performance and lifetimes in various hydrocarbon fuels containing impurities.

Relative Order of Sulfuric Acid, Bisulfate, Hydronium, and Cations at the Air-Water Interface.

Science.gov (United States)

Hua, Wei; Verreault, Dominique; Allen, Heather C

2015-11-04

Sulfuric acid (H2SO4), bisulfate (HSO4(-)), and sulfate (SO4(2-)) are among the most abundant species in tropospheric and stratospheric aerosols due to high levels of atmospheric SO2 emitted from biomass burning and volcanic eruptions. The air/aqueous interfaces of sulfuric acid and bisulfate solutions play key roles in heterogeneous reactions, acid rain, radiative balance, and polar stratospheric cloud nucleation. Molecular-level knowledge about the interfacial distribution of these inorganic species and their perturbation of water organization facilitates a better understanding of the reactivity and growth of atmospheric aerosols and of the aerosol surface charge, thus shedding light on topics of air pollution, climate change, and thundercloud electrification. Here, the air/aqueous interface of NaHSO4, NH4HSO4, and Mg(HSO4)2 salt solutions as well as H2SO4 and HCl acid solutions are investigated by means of vibrational sum frequency generation (VSFG) and heterodyne-detected (HD) VSFG spectroscopy. VSFG spectra of all acid solutions show higher SFG response in the OH-bonded region relative to neat water, with 1.1 M H2SO4 being more enhanced than 1.1 M HCl. In addition, VSFG spectra of bisulfate salt solutions highly resemble that of the dilute H2SO4 solution (0.26 M) at a comparable pH. HD-VSFG (Im χ((2))) spectra of acid and bisulfate salt solutions further reveal that hydrogen-bonded water molecules are oriented preferentially toward the bulk liquid phase. General agreement between Im χ((2)) spectra of 1.1 M H2SO4 and 1.1 M HCl acid solutions indicate that HSO4(-) ions have a similar surface preference as that of chloride (Cl(-)) ions. By comparing the direction and magnitude of the electric fields arising from the interfacial ion distributions and the concentration of each species, the most reasonable relative surface preference that can be deduced from a simplified model follows the order H3O(+) > HSO4(-) > Na(+), NH4(+), Mg(2+) > SO4(2-). Interestingly

Nitrogen and sulfur co-doped porous graphene aerogel as an efficient electrode material for high performance supercapacitor in ionic liquid electrolyte

Science.gov (United States)

Chen, Yujuan; Liu, Zhaoen; Sun, Li; Lu, Zhiwei; Zhuo, Kelei

2018-06-01

Nitrogen and sulfur co-doped graphene aerogel (NS-GA) is prepared by one-pot process. The as-prepared materials are investigated as supercapacitors electrodes in an ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate, EMIMBF4) electrolyte. The NS-GA is characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy scanning electron microscopy. The results show that the NS-GA has hierarchical porous structure. Electrochemical performance is investigated by cycle voltammetry and galvanostatic charge-discharge. Notably, the supercapacitor based on the NS-GA-5 possesses a maximum energy density of 100.7 Wh kg-1 at power density of 0.94 kW kg-1. The electrode materials also offer a large specific capacitance of 203.2 F g-1 at a current density of 1 A g-1 and the capacitance retention of NS-GA-5 is 90% after 3000 cycles at a scan rate of 2 A g-1. The NS-GA-5 with numerous advantages including low cost and remarkable electrochemical behaviors can be a promising electrode material for the application of supercapacitors.

Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses.

Science.gov (United States)

Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Cheng, Min; Zhang, Xiaomin; Liu, Lei

2018-03-09

Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species ( Quercus glauca ) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500-660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca . These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

Effect of aluminum anodizing in phosphoric acid electrolyte on adhesion strength and thermal performance

Science.gov (United States)

Lee, Sulki; Kim, Donghyun; Kim, Yonghwan; Jung, Uoochang; Chung, Wonsub

2016-01-01

This study examined the adhesive bond strength and thermal performance of the anodized aluminum 6061 in phosphoric acid electrolyte to improve the adhesive bond strength and thermal performance for use in metal core printed circuit boards (MCPCB). The electrolyte temperature and applied voltage were altered to generate varied pore structures. The thickness, porosity and pore diameter of the anodized layer were measured. The pore morphologies were affected most by temperature, which was the driving force for ion transportation. The mechanism of adhesive bond was penetration of the epoxy into the pores. The optimal anodization conditions for maximum adhesive bond strength, 27 MPa, were 293 K and 100V. The maximum thermal conductivity of the epoxy-treated anodized layer was 1.6 W/m·K at 273 K. Compared with the epoxy-treated Al layer used for conventional MCPCBs, the epoxy-treated anodized layer showed advanced thermal performance due to a low difference of thermal resistance and high heat dissipation.

Fuel cell electrolyte membrane with basic polymer

Science.gov (United States)

Larson, James M.; Pham, Phat T.; Frey, Matthew H.; Hamrock, Steven J.; Haugen, Gregory M.; Lamanna, William M.

2012-12-04

The present invention is an electrolyte membrane comprising an acid and a basic polymer, where the acid is a low-volatile acid that is fluorinated and is either oligomeric or non-polymeric, and where the basic polymer is protonated by the acid and is stable to hydrolysis.

A composite of hollow carbon nanospheres and sulfur-rich polymers for lithium-sulfur batteries

Science.gov (United States)

Zeng, Shao-Zhong; Yao, Yuechao; Zeng, Xierong; He, Qianjun; Zheng, Xianfeng; Chen, Shuangshuang; Tu, Wenxuan; Zou, Jizhao

2017-07-01

Lithium-sulfur batteries are the most promising candidates for future high-energy applications because of the unparalleled capacity of sulfur (1675 mAh g-1). However, lithium-sulfur batteries have limited cycle life and rate capability due to the dissolution of polysulfides and the extremely low electronic conductivity of sulfur. To solve these issues, various porous carbons including hollow carbon nanospheres (HCNs) have been used for improving the conductivity. However, these methods still suffer from polysulfides dissolution/loss owing to their weak physical adsorption to polysulfides. Herein, we introduced a covalent grafting route to composite the HCNs and the vulcanized trithiocyanuric acid (TTCA). The composite exhibits a high loading of the vulcanized TTCA by the HCNs with high surface area and large pore volume, and covalent bonds to sulfur, effectively depressing the dissolution of polysulfides. The first discharge capacity of the composite reaches 1430 mAh g-1 at 0.1 C and 1227 mAh g-1 at 0.2 C.

Recovery of mercury from mercury compounds via electrolytic methods

Science.gov (United States)

Grossman, Mark W.; George, William A.

1988-01-01

A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

Restraint stress in lactating mice alters the levels of sulfur-containing amino acids in milk.

Science.gov (United States)

Nishigawa, Takuma; Nagamachi, Satsuki; Ikeda, Hiromi; Chowdhury, Vishwajit S; Furuse, Mitsuhiro

2018-03-30

It is well known that maternal stress during the gestation and lactation periods induces abnormal behavior in the offspring and causes a lowering of the offspring's body weight. Various causes of maternal stress during the lactation period, relating to, for example, maternal nutritional status and reduced maternal care, have been considered. However, little is known about the effects on milk of maternal stress during the lactation period. The current study aimed to determine whether free amino acids, with special reference to sulfur-containing amino acids in milk, are altered by restraint stress in lactating mice. The dams in the stress group were restrained for 30 min at postnatal days 2, 4, 6, 8, 10 and 12. Restraint stress caused a reduction in the body weight of lactating mice. The concentration of taurine and cystathionine in milk was significantly higher in the stress group, though stress did not alter their concentration in maternal plasma. The ratio of taurine concentration in milk to its concentration in maternal plasma was significantly higher in the stress group, suggesting that stress promoted taurine transportation into milk. Furthermore, taurine concentration in milk was positively correlated with corticosterone levels in plasma. In conclusion, restraint stress in lactating mice caused the changes in the metabolism and in the transportation of sulfur-containing amino acids and resulted in higher taurine concentration in milk. Taurine concentration in milk could also be a good parameter for determining stress status in dams.

Effects of Anion Mobility on Electrochemical Behaviors of Lithium–Sulfur Batteries

Energy Technology Data Exchange (ETDEWEB)

Han, Kee Sung; Chen, Junzheng; Cao, Ruiguo; Rajput, Nav Nidhi; Murugesan, Vijayakumar; Shi, Lili; Pan, Huilin; Zhang, Jiguang; Liu, Jun; Persson, Kristin A.; Mueller, Karl T.

2017-10-27

The electrolyte is a crucial component of lithium-sulfur (Li-S) batteries, as it controls polysulfide dissolution, charge shuttling processes, and solid-electrolyte interphase (SEI) layer formation. Experimentally, the overall performance of Li-S batteries varies with choice of solvent system and Li-salt used in the electrolyte, and a lack of predictive understanding about the effects of individual electrolyte components inhibits the rational design of electrolytes for Li-S batteries. Here we analyze the role of the counter anions of common Li salts (such as TfO-, FSI-, TFSI-, and TDI-) when dissolved in DOL/DME (1:1 vol.) for use in Li-S batteries. The evolution of ion-ion and ion-solvent interactions due to vari-ous anions was analyzed using 17O NMR and pulsed-field gradient (PFG) NMR and then correlated with electrochemi-cal performance in Li-S cells. These data reveal that the for-mation of the passivation layer on the anode and the loss of active materials from the cathode (evidenced by polysulfide dissolution) are related to anion mobility and affinity with lithium polysulfide, respectively. For future electrolyte de-sign, anions with lower mobility and weaker interactions with lithium polysulfides may be superior candidates for increasing the long-term stability of Li-S batteries.

Sulfur recirculation for increased electricity production in Waste-to-Energy plants.

Science.gov (United States)

Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper

2014-01-01

Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Determination of sulfur in steels by isotope dilution mass spectrometry after dissolution with sealed tube

International Nuclear Information System (INIS)

Watanabe, Kazuo

1981-01-01

The scaled tube dissolution technique was studied for the complete conversion of sulfur in steels to sulfate. Isotope dilution mass spectrometry was used for the determination of sulfur in the sulfate. Sample (0.5 g) was dissolved in nitric acid (7 ml) and hydrochloric acid (3 ml) in a scaled borosilicate glass tube on being heated above 180 0 C overnight. Nitrate ions were removed by repeated evaporation with hydrochloric acid. The residue was dissolved in hydrochloric acid. Sulfate was reduced with a mixture of hydrochloric, hydroiodic and hypophosphorous acids; hydrogen sulfide evolved was absorbed in cadmium acetate solution, then converted to silver sulfide, which was burned to sulfur dioxide in pure oxygen at low pressure, for isotopic analysis. Analytical blank in whole procedure was 0.8 μg of sulfur. This technique was applied to the determination of sulfur in NBS low alloy steels. The principal cause of low values obtained by the open beaker dissolution technique was evaporation losses of sulfur as sulfur dioxide during the dissolution. (author)

Aqueous solutions of acidic ionic liquids for enhanced stability of polyoxometalate-carbon supercapacitor electrodes

Science.gov (United States)

Hu, Chenchen; Zhao, Enbo; Nitta, Naoki; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb

2016-09-01

Nanocomposites based on polyoxometalates (POMs) nanoconfined in microporous carbons have been synthesized and used as electrodes for supercapacitors. The addition of the pseudocapacitance from highly reversible redox reaction of POMs to the electric double-layer capacitance of carbon lead to an increase in specific capacitance of ∼90% at 1 mV s-1. However, high solubility of POM in traditional aqueous electrolytes leads to rapid capacity fading. Here we demonstrate that the use of aqueous solutions of protic ionic liquids (P-IL) as electrolyte instead of aqueous sulfuric acid solutions offers an opportunity to significantly improve POM cycling stability. Virtually no degradation in capacitance was observed in POM-based positive electrode after 10,000 cycles in an asymmetric capacitor with P-IL aqueous electrolyte. As such, POM-based carbon composites may now present a viable solution for enhancing energy density of electrical double layer capacitors (EDLC) based on pure carbon electrodes.

Gelled-electrolyte batteries for electric vehicles

Energy Technology Data Exchange (ETDEWEB)

Tuphorn, H. (Accumulatorenfabrik Sonnenschein GmbH, Buedingen (Germany))

1992-09-15

Increasing problems of air pollution have pushed activities of electric vehicle projects world-wide and in spite of projects for developing new battery systems for high energy densities, today lead/acid batteries are almost the single system, ready for technical usage in this application. Valve-regulated lead/acid batteries with gelled electrolyte have the advantage that no maintenance is required and because the gel system does not cause problems with electrolyte stratification, no additional appliances for central filling or acid addition are required, which makes the system simple. Those batteries with high density active masses indicate high endurance results and field tests with 40 VW-CityStromers, equipped with 96 V/160 A h gel batteries with thermal management show good results during four years. In addition, gelled lead acid batteries possess superior high rate performance compared with conventional lead/acid batteries, which guarantees good acceleration results of the car and which makes the system recommendable for application in electric vehicles. (orig.).

Gelled-electrolyte batteries for electric vehicles

Science.gov (United States)

Tuphorn, Hans

Increasing problems of air pollution have pushed activities of electric vehicle projects worldwide and in spite of projects for developing new battery systems for high energy densities, today lead/acid batteries are almost the single system, ready for technical usage in this application. Valve-regulated lead/acid batteries with gelled electrolyte have the advantage that no maintenance is required and because the gel system does not cause problems with electrolyte stratification, no additional appliances for central filling or acid addition are required, which makes the system simple. Those batteries with high density active masses indicate high endurance results and field tests with 40 VW-CityStromers, equipped with 96 V/160 A h gel batteries with thermal management show good results during four years. In addition, gelled lead/acid batteries possess superior high rate performance compared with conventional lead/acid batteries, which guarantees good acceleration results of the car and which makes the system recommendable for application in electric vehicles.

Sulfur, selenium, tellurium and polonium

International Nuclear Information System (INIS)

Berry, F.J.

1987-01-01

This chapter on the coordination compounds of sulfur, selenium, tellurium and polonium starts with an introduction to the bonding, valence and geometry of the elements. Complexes of the group VIB elements are discussed with particular reference to the halo and pseudohalide complexes, oxo acid complexes, oxygen and nitrogen donor complexes and sulfur and selenium donor complexes. There is a section on the biological properties of the complexes discussed. (UK)

Comparison between female and male of demand of sulfur-containing amino acid of domestic silk worms

International Nuclear Information System (INIS)

Shinbo, Hiroshi; Inokuchi, Tamio

1977-01-01

Comparison of the demand of sulfur-containing amino acid (methionine and cystine) of young domestic silk worms was made between female and male using amino acid diet, and the relation among growth, blood protein and ninhydrin positive substance concentration was discussed. When 3 mg/g of methionine was added to the diet, the growth promotion effect of cystine was hardly recognized for male, while no addition of cystine showed inferior growth for female, however the normal growth was recognized when more than 1 mg/g was added. Accordingly, it is recognized that the female requires more sulfur-containing amino acid than the male. The relationship between the addition of methionine and cystine and the blood protein concentration showed the tendency to conform to the growth approximately. In the effects of blood protein concentration due to diet condition, the difference between female and male were recognized. The relationship between the addition of methionine and cystine in the diet and the ninhydrin positive substance concentration was high in case of the lack of methionine, but the relationship to cystine addition and the difference between female and male were not clear. As a result of measuring 14 CO 2 exhaled from the young worms injected with DL-cystine-1- 14 C, the resolution of cystine in the living body of female was lower than that of male. (Iwakiri, K.)

Lithiated Nafion as polymer electrolyte for solid-state lithium sulfur batteries using carbon-sulfur composite cathode

Science.gov (United States)

Gao, Jing; Sun, Chunshui; Xu, Lei; Chen, Jian; Wang, Chong; Guo, Decai; Chen, Hao

2018-04-01

Due to flexible property and light weight, the lithiated Nafion membrane swollen with PC (PC-Li-Nafion) has been employed as both solid-state electrolyte and separator to fabricate solid-state Li-S cells. The electrochemical measurements of PC-Li-Nafion membrane show that its Li-ion transference number is 0.928, ionic conductivity of 2.1 × 10-4 S cm-1 can be achieved at 70 °C and its electrochemical window is 0 ∼ +4.1 V vs. Li+/Li. It is observed that the Li dendrites are suppressed by using PC-Li-Nafion membrane due to its single-ion conducting property. The amounts of Li-Nafion resin binder and conductive carbon in the cathode are optimized as 40% and 10% respectively to make a balance of ionic and electronic conductivities. A thin-layer Li-Nafion resin with a thickness of around 2 μm is fabricated between the cathode and PC-Li-Nafion membrane to improve the interfacial contact and further enhance the specific capacity of the cell. When measured at 70 °C, the Li-S cell delivers a reversible specific capacity of 1072.8 mAh g-1 (S) at 0.05 C and 895 mAh g-1 (S) at 1 C. The capacity retention at 1 C is 89% after 100 cycles. These results suggest that high-performance solid-state Li-S cells can be fabricated with the Li-Nafion polymer electrolyte.

Electrodialytic separation of Cu(II) and As(V) in acidic electrolytes; Separacion electrodialitica de Cu(II) y As(V) en electrolitos acidos

Energy Technology Data Exchange (ETDEWEB)

Ibanez, J. P.; Ipinza, J.; Cifuentes, L.

2007-07-01

The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. the effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II) transport rate was 0.75 mol/m''2/h and the As(V) transport rate was 0.002 mol/m''2/h. An efficient separation between Cu(II) and As(V) was achieved; Generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well. (Author) 23 refs.

Bioleaching of metals from soils or sediments using the microbial sulfur cycle

NARCIS (Netherlands)

Tichy, R.

1998-01-01

Reduced inorganic sulfur species like elemental sulfur or sulfide are sensitive to changes in oxidative environments. Generally, inorganic reduced sulfur exists in natural environments in a solid phase, whereas its oxidation leads to sulfur solubilization and a production of acidity. This

Study and make sulfur dioxide treatment equipment for degradation process of fine silicate zircon ore by sulfuric acid

International Nuclear Information System (INIS)

Cao Dinh Thanh; Le Xuan Thu; Tran Van Hoa; Pham Kim Thoa

2003-01-01

The against absorbent method was researched by research group to solve the above issue. This method was carried out by adsorbent lime-milk agent on the buffer of porous material with diameter D=9 cm and height H=1.2 m. The main parameters were gained: absorbent effect reached 98% with lime-milk concentration of 14% in water, against air flow speed of 0.7 m/s and lime-milk output of 0.45 liter/minute. Base on the above main researched parameter, the SO 2 treatment equipment system by sulfuric acid was worked out with the scale of 0.5 ton/batch/day; absorbent tower diameter D=0.47 m, buffer height H=3.5 m and expenditure of 33.2 kg CaO/ton of zircon silicate. (author)

Effects of MoO42- in the Acidic Electrolytes on the Corrosion Behavior of Sensitized 304 Stainless Steel in the Acidic Electrolytes

International Nuclear Information System (INIS)

Choe Han Cheol; Kim, Kwan Hyu

1995-01-01

The corrosion resistance of sensitized 304 stainless steel was investigated potentiodynamically in the molybdate-containing electrolytes. The composition of the passive film formed in the passive region was analyzed by using the x-ray photoelectron spectroscopy(XPS). It was observed that the addition of molybdate to various electrolytes such as H 2 SO 4 , KSCN and HCI solutions increased the corrosion potential, pitting potential and repassivation potential of the sensitized 304 stainless steel, and decreased the active current density, passive current density and reactivation current density. However, the passive current density in H 2 SO 4 solution increased with the molybdate addition. When the molybdate was added to the KSCN and the HCI solutions, the number and the size of pits decreased remarkably. The results of XPS analysis showed that the passive film formed after passivation in the molybdate-containing electrolytes consisted mainly of oxyhydrates and Mo oxides which would lower the dissolution rate of metal at the active sites such as Cr 23 C 6 precipitates

Density functional theory analysis of the reaction pathway for methane oxidation to acetic acid catalyzed by Pd2+ in sulfuric acid.

Science.gov (United States)

Chempath, Shaji; Bell, Alexis T

2006-04-12

Density functional theory has been used to investigate the thermodynamics and activation barriers associated with the direct oxidation of methane to acetic acid catalyzed by Pd2+ cation in concentrated sulfuric acid. Pd2+ cations in such solutions are ligated by two bisulfate anions and by one or two molecules of sulfuric acid. Methane oxidation is initiated by the addition of CH4 across one of the Pd-O bonds of a bisulfate ligand to form Pd(HSO4)(CH3)(H2SO4)2. The latter species will react with CO to produce Pd(HSO4)(CH3CO)(H2SO4)2. The most likely path to the final products is found to be via oxidation of Pd(HSO4)(CH3)(H2SO4)2 and Pd(HSO4)(CH3CO)(H2SO4)2 to form Pd(eta2-HSO4)(HSO4)2(CH3)(H2SO4) and Pd(eta2-HSO4)(HSO4)2(CH3CO)(H2SO4), respectively. CH3HSO4 or CH3COHSO4 is then produced by reductive elimination from the latter two species, and CH(3)COOH is then formed by hydrolysis of CH3COHSO4. The loss of Pd2+ from solution to form Pd(0) or Pd-black is predicted to occur via reduction with CO. This process is offset, though, by reoxidation of palladium by either H2SO4 or O2.

New nanocomposites of polystyrene with polyaniline doped with lauryl sulfuric acid

Science.gov (United States)

Pud, A. A.; Nikolayeva, O. A.; Vretik, L. O.; Noskov, Yu. V.; Ogurtsov, N. A.; Kruglyak, O. S.; Fedorenko, E. A.

2017-08-01

This work is concentrated on synthesis and investigation of new core-shell nanocomposites of polystyrene (PS) with doped polyaniline (PANI). The latex containing PS nanoparticles with sizes of 15-30 nm was prepared by microemulsion polymerization of styrene in water media. The PS/PANI nanocomposites were synthesized by chemical oxidative polymerization of aniline in the PS latex media in a presence of lauryl sulfuric acid (LSA), which served as both dopant and plasticizer. The real content of PANI in the synthesized nanocomposites was determined by UV-Vis spectroscopy method. The composition of the nanocomposites and oxidation state of the doped polyaniline were characterized by FTIR spectroscopy. The core-shell morphology of the nanocomposite nanoparticles was proved by transmission and scanning electron microscopy. It was found that conductivity and thermal behavior in air of these nanocomposites not only nonlinearly depended on the doped polyaniline content but also were strongly effected both by plasticizing properties of the acid-dopant and presence of the polyaniline shell. A possibility of application of these nanocomposites as sensor materials has been demonstrated.

Supply, storage and handling of elemental sulfur derived from sour gas

International Nuclear Information System (INIS)

Clark, P.D.; Davis, P.M.; Dowling, N.I.; Calgary Univ., AB

2003-01-01

This presentation reviews the supply picture for solid elemental sulfur. It also assesses methods for its storage as well as the disposal of the precursor hydrogen sulfide (H 2 S) by acid gas injection. Both above and below ground block storage is considered environmentally acceptable for sulfur storage as long as measures are taken to minimize the physical and biological breakdown of the sulfur. The preferred option is to store solid elemental sulfur underground, particularly if it is to remain in storage for a prolonged period. Future changes in supply of sulfur will likely be controlled by incremental production of sour gas and utilization of oil sands bitumen. It is expected that future sulfur production from conventional crude oil will remain static or will slowly decrease. The degree to which acid gas injection is applied to large sour gas developments in the Middle East and the Caspian regions will have a significant impact on world sulfur supply. 9 refs., 1 tab., 5 figs

Sulfur sources in protein supplements for ruminants

Directory of Open Access Journals (Sweden)

Cássio José da Silva

2014-10-01

Full Text Available The present study evaluates the efficiency of different sulfur sources for ruminant nutrition. The fiber digestibility and the amino acid profile were analyzed in the duodenal digesta of crossbred steers fed Brachiaria dictyoneurahay. The sources utilized were elemental sulfur (ES70S, elemental sulfur (ES98S; calcium sulfate in hydrated (HCS, CaSO4.2H2O, and anhydrous (ACS, CaSO4, forms; and ammonium sulfate (AS, (NH42SO4, keeping a nitrogen:sulfur ratio of 11:1. The iso-protein supplements had 50% of protein in the total dry matter (DM. Five Holstein × Zebu steers, which were fistulated in the rumen and abomasum, were distributed in a 5 × 5 Latin square. The different sulfur sources in the supplement did not affect any of the evaluated nutritional factors, such as intake of hay dry matter and protein supplement, crude protein (CP, neutral detergent fiber corrected for ash and protein (NDFap, organic matter (OM, non-fibrous carbohydrate (NFC, ether extract (EE, total digestible nutrients (TDN, NDFap and CP digestibility coefficients, ruminal pH, and ruminal ammonia concentration. The concentrations of amino acids available in the abomasal digesta did not differ significantly in the tested diets. The sulfur sources evaluated in the present study are suitable as supplement for cattle, and their employment may be important to avoid environmental contaminations.

An AFM and XPS study of corrosion caused by micro-liquid of dilute sulfuric acid on stainless steel

International Nuclear Information System (INIS)

Wang Rongguang

2004-01-01

Micro-liquid of dilute sulfuric acid deposited on SUS304 steel surface were observed with the ac non-contact mode of an atomic force microscopy (AFM), and the detail of the corrosion process caused by them was investigated with the contact mode of the AFM, X-ray photoelectron spectroscopy (XPS) and wavelength dispersive X-ray spectroscopy (WDXS). As a result, even not applying bias voltages between the tip of the cantilever and the specimen, micro-liquid of sulfuric acid can be successfully imaged using the ac non-contact mode of AFM. Two shapes of micro-acid, i.e., micro-droplets and micro-films, were found to co-exist on the specimen surface. On areas covered by micro-films of acid, only small corrosion product particles appeared and no corrosion pits were found. Beneath micro-droplets, corrosion reaction continue to produce pits until they were all consumed to form a corrosion product (mainly iron oxides) with almost the same shape with the droplet. The total corrosion reaction time was speculated to be between 690 and 1500 ks. The corrosion product formed from micro-droplets was believed to be a process of accumulating small corrosion product particles from the liquid/substrate interface to the surface of the formerly produced corrosion product. The XPS and WDXS analysis also supports the above results

Sulfur isotope evidence for the contemporary formation of pyrite in a coastal acid sulfate soil

International Nuclear Information System (INIS)

Bush, R.T.; Sullivan, L.A.; Prince, K.; White, I.

2000-01-01

The sulfur isotopic composition of pyrite (FeS 2 ), greigite (Fe 3 S 4 ) and pore-water sulfate was determined for a typical coastal acid sulfate soil (ASS). Greigite occurs only in the partially oxidised upper-most pyrite sediments as blackish clusters within vertical fissures and other macro-pores. The concentration of pyrite was an order of magnitude greater than greigite in this layer, continuing through the underlying reduced estuarine sediments. δ 34 S of pyrite (0.45 per mil) associated with greigite accumulations were distinctly different to the bulk average for pyrite (-3.7 per mil), but similar to greigite (0.9 per mil). Greigite is meta-stable under reducing conditions, readily transforming to pyrite. The transformation of iron monosulfides (including greigite) to pyrite is a sulfur-isotope conservative process and therefore, these observations indicate that pyrite is forming from greigite at the oxic/anoxic boundary

Biodegradation tests of mercaptocarboxylic acids, their esters, related divalent sulfur compounds and mercaptans.

Science.gov (United States)

Rücker, Christoph; Mahmoud, Waleed M M; Schwartz, Dirk; Kümmerer, Klaus

2018-04-17

Mercaptocarboxylic acids and their esters, a class of difunctional compounds bearing both a mercapto and a carboxylic acid or ester functional group, are industrial chemicals of potential environmental concern. Biodegradation of such compounds was systematically investigated here, both by literature search and by experiments (Closed Bottle Test OECD 301D and Manometric Respirometry Test OECD 301F). These compounds were found either readily biodegradable or at least biodegradable to a significant extent. Some related compounds of divalent sulfur were tested for comparison (mercaptans, sulfides, disulfides). For the two relevant monofunctional compound classes, carboxylic acids/esters and mercaptans, literature data were compiled, and by comparison with structurally similar compounds without these functional groups, the influence of COOH/COOR' and SH groups on biodegradability was evaluated. Thereby, an existing rule of thumb for biodegradation of carboxylic acids/esters was supported by experimental data, and a rule of thumb could be formulated for mercaptans. Concurrent to biodegradation, abiotic processes were observed in the experiments, rapid oxidative formation of disulfides (dimerisation of monomercaptans and cyclisation of dimercaptans) and hydrolysis of esters. Some problems that compromise the reproducibility of biodegradation test results were discussed.

Chemical decontamination method for radioactive metal waste

International Nuclear Information System (INIS)

Onuma, Tsutomu; Tanaka, Akio; Shibuya, Sadao.

1991-01-01

When contaminants mainly composed of copper remained on the surface of stainless steel wastes sent from an electrolytic reduction as a first step are chemically decontaminated, metal wastes are discriminated to carbon steel wastes and stainless steel wastes. Then, the carbon steel wastes are applied only with the first step of immersing in a sulfuric acid solution, and stainless steel wastes are applied with a first step of immersing into a sulfuric acid solution for electrolytic reduction for a predetermined period of time and a second step of immersing into a liquid in which an oxidative metal salt is added to sulfuric acid. The decontamination liquid which is used for immersing the stainless steel wastes in the second step and the oxidation force of which is lowered is used as the sulfuric acid solution in the first step for the carbon steel wastes. In view of the above, the decontamination liquid of the second step can be utilized most effectively, enabling to greatly decrease the secondary wastes and to improve decontamination efficiency. (T.M.)

Sulfur dioxide leaching of spent zinc-carbon-battery scrap

Energy Technology Data Exchange (ETDEWEB)

Avraamides, J.; Senanayake, G.; Clegg, R. [A.J. Parker Cooperative Research Centre for Hydrometallurgy, Murdoch University, Perth, WA 6150 (Australia)

2006-09-22

Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25{sup o}C. Alkaline leaching with 6M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30min at 30{sup o}C using 0.1-1.0M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1M to 2M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide. (author)

Sulfur availability regulates plant growth via glucose-TOR signaling.

Science.gov (United States)

Dong, Yihan; Silbermann, Marleen; Speiser, Anna; Forieri, Ilaria; Linster, Eric; Poschet, Gernot; Allboje Samami, Arman; Wanatabe, Mutsumi; Sticht, Carsten; Teleman, Aurelio A; Deragon, Jean-Marc; Saito, Kazuki; Hell, Rüdiger; Wirtz, Markus

2017-10-27

Growth of eukaryotic cells is regulated by the target of rapamycin (TOR). The strongest activator of TOR in metazoa is amino acid availability. The established transducers of amino acid sensing to TOR in metazoa are absent in plants. Hence, a fundamental question is how amino acid sensing is achieved in photo-autotrophic organisms. Here we demonstrate that the plant Arabidopsis does not sense the sulfur-containing amino acid cysteine itself, but its biosynthetic precursors. We identify the kinase GCN2 as a sensor of the carbon/nitrogen precursor availability, whereas limitation of the sulfur precursor is transduced to TOR by downregulation of glucose metabolism. The downregulated TOR activity caused decreased translation, lowered meristematic activity, and elevated autophagy. Our results uncover a plant-specific adaptation of TOR function. In concert with GCN2, TOR allows photo-autotrophic eukaryotes to coordinate the fluxes of carbon, nitrogen, and sulfur for efficient cysteine biosynthesis under varying external nutrient supply.

Influence of sulfur and nitrogen supply on the susceptibility of Pisum sativum to SO/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Klein, H; Jaeger, H J; Steubing, L

1974-01-01

The susceptibility of Pisum to SO/sub 2/ injury was examined in relation to the sulfur and nitrogen nutrition. The injury was measured by comparing the dry matter yield to control and treated plants. SO/sub 2/ effects on metabolism were established by determining the content of organic and inorganic sulfur and, indirectly, by measuring total nitrogen, amino acid nitrogen, and protein nitrogen. The plants grown in nutrient solutions deficient in sulfur or nitrogen showed a decreased sensitivity to SO/sub 2/ pollution compared to the control. The higher content of amino acid nitrogen and organic sulfur of the plants grown in a nitrogen-deficient solution suggests that an increased synthesis of sulfur containing amino acids occurs. The slighter injury of the plants deficient in sulfur may be explained by the delayed sulfur supply.

Sulfur in human nutrition - effects beyond protein synthesis

NARCIS (Netherlands)

Gertjan Schaafsma

2008-01-01

That sulfur is essential to humans is based on the requirement of S-animo acids for normal growth and maintenance of nitrogen balance and not on the optimization of metabolic proccesses involving the synthesis of non-protein sulphur containing compounds. This paper reviews the significance of sulfur

Jacques Loeb (1859-1924) and His Forgotten Contributions to Electrolyte and Acid-Base Physiology in The Organism as a Whole.

Science.gov (United States)

Sgambato, Francesco; Sgambato, Ester; De Santo, Natale Gaspare

2016-02-01

Jacques Loeb (1859-1924) was the founder of the Journal of General Physiology which he co-directed in association with W.J.V. Osterhout in the years 1918-1924. Having worked (1889-1891)at the Marine Zoological Station of Naples, newly founded by Anton Dohrn, he was imprinted for life. A strong investigator used to perform the experiments personally. Loeb was engaged lifelong in the explanation of life on physico-chemical basis. He touched various fields (being a creative scientist full of ideas), and centered on the exchanges of electrolytes, acids and bases between the body and sea water in fish. He identified two equations: {[K+]+[Na+]}: {[Ca++]+[Mg++]} (Loebs 1st equation) {[K+]+[Na+]}: {[H+]+[Ca++]+[Mg++]} (Loebs final equation) Even nowadays these equations may have applications in a wide list of electrolyte and acid-base disturbances. Unfortunately his heredity has been dissipated.