Low Flash Point Research Articles

Hazardous waste dewatering and dry mass reduction through hydrophobic modification by a facile one-pot, alkali-assisted hydrothermal reaction

Hazardous waste dewatering is important for volume reduction and further treatment. Hazardous organic wastes with low ratio of free to bound water, and low flash point are difficult to dewater and pose an explosion risk for conventional thermal drying. Here, we develop a facile one-pot, alkali-assisted hydrothermal treatment (AHT) method for cost-efficient hazardous waste dewatering, dry mass minimization and volume reduction. Wet paint sludge (WPS), a hazardous organic waste, was reduced (79% by total weight and 52% by dry mass) by dewatering through AHT hydrophobic modification, and the product was nonflammable. Conversion of bound water to free water enhanced WPS dissolution for further decomposition. Alkali was critical for boosting ether demethylation in the solid phase, and cleavage of ethers forming alcohols that facilitated transfer of solid mass into the liquid phase. Polar functional groups were eliminated through AHT, which increased the relative abundance of hydrophobic functional groups on the surface of solid residues and promoted dewatering. We also demonstrate that AHT can be widely adapted and scaled up to treat various hazardous organic waste streams, which is of significant industrial and environmental interest.

Phase behavior and biofuel properties of waste cooking oil-alcohol-diesel blending in microemulsion form

Waste cooking oil (WCO) can be used as an energy source to reduce fossil fuel consumption; however, WCO has high viscosity which restricts direct use in diesel engines. Emulsification techniques can be employed for fuel preparation by selecting suitable surfactants and WCO, diesel and butanol or ethanol ratios using a pseudo-ternary phase diagram. Results indicated that a WCO-diesel fuel blend (WDF) with butanol required no surfactants for homogeneous phase blending compared to WDF with ethanol. Phase behavior of WDF-ethanol blends with hydrophobic surfactants was more suitable than WDF-ethanol blends with more hydrophilic surfactants. Kinematic viscosity of WDF blends depended on the amount of surfactant and its hydrophile-lipophile balance (HLB) value. WCO content was determined as a significant factor contributing to WDF viscosity (p < 0.05). Biofuel blends containing 70% v/v diesel fuel, 15–20% v/v WCO, and 15–20% v/v ethanol with Dehydol LS1 or Span 80 at ethanol:surfactant ratio of 9:1 were selected for further analysis of relevant fuel properties. All selected WDFs gave emulsion droplet size at 200 nm or less. Other properties such as water content, carbon residue and copper strip corrosion met values specified by diesel and biodiesel fuel standards. Acid value of WDFs exceeded the standard due to high acid content of WCO. WDFs with ethanol/surfactants showed higher oxidative stabilities than WDFs with butanol. In terms of safety, conditions for storage and transport should be applied for WDFs because of their low flash point. WDFs obtained by this technique may be used in unmodified diesel engines but engine performance should be monitored.

Biodiesel Potentials and Lubricating Properties of &amp;lt;i&amp;gt;Citrus sinensis&amp;lt;/i&amp;gt; Seed Oil

Potentials of <i>Citrus sinensis</i> seed oil were evaluated for its biodiesel and lubricating properties. The oil of <i>C. sinensis</i> seed was extracted using n-hexane and then transesterified using various methanol: oil ratios. The physicochemical properties of the oil and the resultant biodiesel, such as viscosity, acid value, iodine value, free fatty acid value, pour point, cloud point, smoke point, specific gravity and surface tension, were determined. The raw oil exhibited a low oxidative stability, while the biodiesel ratio with the highest methanol content had a biodiesel potential that could compete favourably with that of fossil diesel. The test for the burning efficiency of the respective biodiesel ratios indicated that the ratio with the lowest alcohol content had the best burning efficiency. This was evident from its relatively low flash point. The study concluded that the non-edible oil obtained from the seeds of <i>C. sinensis</i> could serve as a highly reliable substitute for the production of very good quality biodiesel fuels.

Leidenfrost evaporation of a single droplet of gasoline blends of ethanol

The increase in energy consumption is observed since the middle of the 20th century. At the same time, the International Energy Agency (IEA) forecasts a 50% increase in energy consumption by 2030. One of the ways to reduce the consumption of such fuels are small additions received from natural gas and renewable energy sources. Mixtures of alcohols with gasoline and diesel oil are produced. Their small additions allow for a certain share of energy from renewable sources without a noticeable change in the combustion characteristics of such fuels. The paper presents the studies on the evaporation of drops of gasoline with a total composition CnHn+2, where n = 5 to 7. Its components are distillation products of crude oil with a low flash point. It is a colourless liquid mixture which main components are: n-heptane, neohexane and cyclopentane. The evaporation characteristics of such a drop with the addition of ethanol are also given. The result of the conducted research is the loss of mass during the drop carried above the surface with temperature above the Leidefrost point.

Investigation of Corrosiveness Biodiesel Blends Using Polypyrrole Chitosan-Cobalt/Ferrite Nanocomposite

Corrosiveness of palm oil biodiesel blends was measured using surface plasmon resonance with polypyrrole chitosan cobalt ferrite nanoparticles sensing layers. Diesel fuel which is relatively corrosive and lower flash point is often mixed with biodiesel of low corrosiveness and higher flash point. Biodiesel blend fuels were prepared from the mixture of normal palm oil biodiesel and diesel fuel where the percentage of the mixture was in the range of 10–90%. The corrosiveness of all the samples was in the class 1a according to the standard copper strip test, but the concentrations of copper and iron ion that were released in biodiesel blend were distinctly different. In this article, the corrosiveness of biodiesel blend was investigated using surface plasmon resonance from the measurement the concentration of copper and iron ions. The corrosiveness of biodiesel blends consistently decreased with increasing the concentration of biodiesel. Moreover, the sensitivity of polypyrrole chitosan /cobalt ferrite and polypyrrole chitosan sensing layer was compared. Consequently, the polypyrrole chitosan cobalt ferrites have sensitivity higher than polypyrrole chitosan sensing layer.

Chemical and microscopic investigation of co-pyrolysis of crumb tire rubber with waste cooking oil at mild temperature

Approximate rubber/bitumen homogeneous system formed by desulfurization and degradation of crumb tire rubber in bitumen under high temperature is beneficial to enhance the storage stability of rubberized bitumen. However, the main problems during the processing of desulfurized and degraded rubberized bitumen are aging caused by volatilization of light components, and burning or explosion due to the direct utilization of low flash point bitumen. Therefore, waste cooking oil was proposed as a safer medium to desulfurize and degrade crumb rubber prior to production of rubberized bitumen. This study focused on the feasibility and effectiveness of the application of waste cooking oil in desulfurizing and degrading rubber particles through co-pyrolysis of them at mild temperature (240–280 °C). Chemical and microscopic analyses were performed to investigate the structural changes of vulcanized rubber. Results showed that solubility of rubber powder reached above 60 wt% after pyrolysis in waste cooking oil, which increased with higher temperatures and more of oil, while increased to a maximum at 2 h and then decreased with the extension of time. The rubber hydrocarbon content decreased greatly, and dramatic reduction of carbon, hydrogen and sulfur elements happened according to component and elemental analyses. The surface of pyrolysis product was even and smooth without obvious rubber particles. The grooves and cavities of rubber residues in scanning electron microscopy micrographs proved that shedding of degraded polymer molecules occurred. Fourier transform infrared spectra revealed that breakage of carbon-sulfur, carbon=carbon and sulfur=oxygen bonds took place during pyrolysis, with appearance of natural rubber characteristic peak.

Novel Materials for Performance Enhancement in Lithium Batteries – Electrolytes and Additives

One of the main challenges for the coming decades is the development of new technologies for storage of electrochemical energy. The supply and management of energy are particularly at the centre of our daily concerns and represent a socio-economic priority. The depletion of oil reserves and necessity to reduce carbon dioxide emissions, stimulate the development of electric vehicles. Lithium-ion battery (LIB) seems to be the best choice for electric vehicles, and perhaps for the storage of electricity from wind turbines or photovoltaic cells. Although lithium-ion technology has known remarkable improvements over the last two decades in terms of enhanced energy density, a technological breakthrough seems to be necessary to further increase the energy density, charge rate, safety and longevity. The performance of LIB’s can be improved either by optimizing the electrolyte, or by developing electrode materials. Lithium batteries use organic electrolytes due to their wide operating voltage. For lithium ion rechargeable batteries, these electrolytes are almost universally based on combinations of linear and cyclic alkyl carbonates. These electrolytes make possible the use of Li as the anodic active component and results in an already high power and energy density characteristics of the Li ion chemistries. This presentation will include major highlights of innovative routes (seed ideas of Prof. Michel Armand) to overcome the shortcomings in lithium batteries. Ethers have been sought after as an alternative electrolyte solvent in order to get rid of the alkyl carbonate, fragile to reduction (RO-, RCO2 •) with low flash points (dimethyl carbonate, DMC, Fp = 17 °C). Although high conductivities could be achieved they co-intercalate in the graphite negative electrode at the same time as the cation. A new class of glymes called “Hindered glymes” (patent pending) developed in order to prevent solvent co-intercalation in cells employing graphite anodes will be presented. Moreover previous glyme solvates (1:1) when used in an operating battery with lithium-exchanging electrodes have problems of solvent balance at the electrodes. At the anode (negative electrode on discharge, positive on charge) when lithium is injected in the electrolyte, there is no free glyme available to solvate the corresponding salt, and this will lead to its precipitation. Conversely, at the cathode the desolvation process frees some glyme, not coordinated to Li+ and this lowers the potential at which the electrolyte get oxidized. In order to address both these concerns redesigned PEG ethers with unsymmetrical end groups, ethyl and butyl that overcomes the above mentioned problems will be discussed. Electrolyte additives like Boron Esters (a new family of Boron complexes-patent granted), that forms adducts with anions bound in a dynamic manner and exchange easily with the same species in a different environment will be introduced as additives for controlling the thickness of SEI layers formed in lithium batteries. Lastly cathode additives “Sacrificial Salts” (patent granted), a relatively different approach towards overlithiation for compensating initial charge irreversibility in lithium batteries would also be highlighted.

Characterization of Hemp (Cannabis sativa L.) Biodiesel Blends with Euro Diesel, Butanol and Diethyl Ether Using FT-IR, UV–Vis, TGA and DSC Techniques

Blending biodiesel–diesel blends with alternative fuels such as butanol and diethyl ether becomes an interesting area of research. Butanol is becoming a popular fuel due to its renewable nature and superior properties compared to ethanol. Diethyl ether can be considered as a renewable fuel as it can be produced from bioethanol through easy dehydration process. This paper aims to study the physicochemical properties of biodiesel produced from Hemp (Cannabis sativa L.) and its blends with Euro diesel, butanol and diethyl ether. Furthermore, characterizations such as DSC, FT-IR, UV–Vis and TGA were also analyzed. Most of the properties of biodiesel satisfy EN 14214 and ASTM D6751 standards except iodine value and oxidation stability due to the high degree of unsaturation (128.549). Blending of hemp biodiesel with Euro diesel, butanol and diethyl ether improved the cold flow properties, kinematic viscosity and density. However, flash point decreased dramatically specially when blending with diethyl ether due to its low flash point. Therefore, care should be taken when handling or transporting biodiesel–diesel–diethyl ether blends. This work supports that blending Hemp methyl ester with Euro diesel, butanol and diethyl ether as ternary blends (up to 20%) can be considered as alternatives to fossil diesel in CI diesel engines. Therefore, it is recommended that engine, emissions and combustion characteristics of all blends shall be further investigated.

The machined surface of magnesium AZ31 after rotary turning at air cooling condition

Magnesium is a lightweight metal that is widely used as an alternative to iron and steel. Magnesium has been applied in the automotive industry to reduce the weight of a component, but the machining process has the disadvantage that magnesium is highly flammable because it has a low flash point. High temperature can cause the cutting tool wear and contributes to the quality of the surface roughness. The purpose of this study is to obtain the value of surface roughness and implement methods of rotary cutting tool and air cooling output vortex tube cooler to minimize the surface roughness values. Machining parameters that is turning using rotary cutting tool at speed the workpiece of (Vw) 50, 120, 160 m/min, cutting speed of rotary tool of (Vt) 25, 50, 75 m/min, feed rate of (f) 0.1, 0.15, 0.2 mm/rev, and depth of cut of 0.3 mm. Type of tool used is a carbide tool diameter of 16 mm and air cooling pressure of 6 bar. The results show the average value of the lowest surface roughness on the speed the workpiece of 80 m/min, cutting speed of rotary tool of 50 m/min, feed rate of 0.2 mm/rev, and depth of cut of 0.3 mm. While the average value of the highest surface roughness on the speed the workpiece of 160 m/min, cutting speed of rotary tool of 50 m/min, feed rate of 0.2 mm/rev, and depth of cut of 0.3 mm. The influence of machining parameters concluded the higher the speed of the workpiece the surface roughness value higher. Otherwise the higher cutting speed of rotary tool then the lower the surface roughness value. The observation on the surface of the rotary tool, it was found that no uniform tool wear which causes non-uniform surface roughness. The use of rotary cutting tool contributing to lower surface roughness values generated.

Effects of dilute gas on combustion and emission characteristics of a common-rail diesel engine fueled with isopropanol-butanol-ethanol and diesel blends

Isopropanol-butanol-ethanol (IBE) can be used in engines as an alternative fuel to eliminate the high recovery and separation costs in the production of butanol and also to avoid the corrosivity and low flash point of acetone in acetone-butanol-ethanol (ABE). In this respect, this study is aimed to investigate the performance, combustion and emissions of a single-cylinder, common-rail diesel engine fueled with IBE and diesel blends. Two blends of butanol and diesel fuel, denoted as IBE15 (15% IBE and 85% diesel in volume) and IBE30 (30% IBE and 70% diesel in volume) were tested. Additionally, the experiments in this study were conducted at different diluted gas ratios to achieve low NOx emission. The experimental results show that when the intake charger is gradually diluted, the start of combustion and combustion center for all the tested fuels are remarkably delayed. Compared with pure diesel, the brake thermal efficiency (BTE) for IBE15 is always higher. Butt for IBE30, the BTE is lower than that of pure diesel when the flow rate of the dilute gas is less than 30 L/min. For all the tested fuels, NOx emission reduces while CO and HC emissions increase with the increase of dilute gas. Soot emission for pure diesel and IBE15 drastically increases as the dilute gas increases. However, the increase of dilute gas does not cause the soot emission of IBE30 to significant increase. That is to say, IBE30 coupled with a proper EGR ratio has the potential to reduce NOx and soot emissions simultaneously.

Combustion characteristics of a two-stroke spark ignition UAV engine fuelled with gasoline and kerosene (RP-3)

Purpose The purpose of this paper is to compare the combustion characteristics, including the combustion pressure, heat release rate (HRR), coefficient of variation (COV) of indicated mean effective pressure (IMEP), flame development period and combustion duration, of aviation kerosene fuel, namely, rocket propellant 3 (RP-3), and gasoline on a two-stoke spark ignition engine. Design/methodology/approach This paper is an experimental investigation using a bench test to reflect the combustion performance of two-stroke spark ignition unmanned aerial vehicle (UAV) engine on gasoline and RP-3 fuel. Findings Under low load conditions, the combustion performance and HRR of burning RP-3 fuel were shown to be worse than those of gasoline. Under high load conditions, the average IMEP and the COV of IMEP of burning RP-3 fuel were close to those of gasoline. The difference in the flame development period between gasoline and RP-3 fuel was similar. Practical implications Gasoline fuel has a low flash point, high-saturated vapour pressure and relatively high volatility and is a potential hazard near a naked flame at room temperature, which can create significant security risks for its storage, transport and use. Adopting a low volatility single RP-3 fuel of covering all vehicles and equipment to minimize the number of different devices with the use of a various fuels and improve the application safeties. Originality/value Most two-stroke spark ignition UAV engines continue to combust gasoline. A kerosene-based fuel operation can be applied to achieve a single-fuel policy.

Highly Conductive, Light Weight, Robust, Corrosion‐Resistant, Scalable, All‐Fiber Based Current Collectors for Aqueous Acidic Batteries

AbstractLithium‐ion batteries (LIBs) are integral parts of modern technology, but can raise safety concerns because of their flammable organic electrolytes with low flash points. Aqueous electrolytes can be used in LIBs to overcome the safety issues that come with organic electrolytes while avoiding poor kinetics associated with solid state electrolytes. Despite advances in aqueous electrolytes, current collectors for aqueous battery systems have been neglected. Current collectors used in today's aqueous battery systems are usually metal‐based materials, which are heavy, expensive, bulky, and prone to corrosion after prolonged use. Here, a carbon nanotube (CNT)–cellulose nanofiber (CNF) all‐fiber composite is developed that takes advantage of the high conductivity of CNT while achieving high mechanical strength through the interaction between CNT and CNF. By optimizing the CNT/CNF weight ratio, this all‐fiber current collector can be made very thin while maintaining high conductivity (≈700 S cm−1) and strength (&gt;60 MPa), making it an ideal replacement for heavy metal current collectors in aqueous battery systems.

Igniter-induced hybrids in the 20-l sphere

Dust explosibility is traditionally described by two parameters, namely the maximum explosion pressure, Pmax, and the deflagration index, KSt, usually determined through testing in a closed, pressure-resistant spherical vessel, either 20 L or 1 m3 in volume. These parameters constitute key variables in the design of explosion protection systems, such as venting, suppression or isolation systems.The potential for overdriving dust combustion with pyrotechnical igniters in the 20-l sphere has been recognized, discussed and analyzed for many years, notably in the determination of the minimum explosible and limiting oxygen concentrations, which has led to specific guidelines regarding the ignition source strength in ASTM standards.The current paper presents new experimental evidence that the energy provided by pyrotechnical igniters may, in some instances, physically alter the dust being tested in the 20-l sphere. KSt values can be several times greater in the small vessel compared to those measured in the 1-m3 chamber. Further visual evidence is provided to show that high energy ignition can produce a turbulent flame region, possibly consisting of a hybrid mixture of flammable gas (or vapor) and dust, which can propagate faster than the corresponding pure dust. The experiments suggest that KSt values measured in the 20-l sphere may no longer be representative of a dust deflagration in a real process environment. We recommend additional tests in a 1-m3 chamber when a dust exhibits a low flash point, or when it's KSt is above 300 bar m/s in the 20-l sphere.

Research of quality of motor fuels and oils in agricultural production of Kuban

The quality of fuel and lubricants used in agricultural production was studied in order to assess the effect of their properties on the performance of the engine. The analysis of gasoline determined the following quality indicators: density, presence of mechanical impurities, water content, acid number, the presence of mineral acids and alkalis, fractional distillation of fuel (determination of the boiling and boiling point of 10 % of fuel, 50 % of fuel and 90 % of fuel). When analyzing the properties of diesel fuel, the following indicators of its quality were determined: density, presence of mechanical impurities, water content, flash point, viscosity at 20 °С, presence of mineral acids and alkalis. The evaluation of the quality of motor oils was carried out according to the following parameters: density, viscosity at 50 °C, viscosity at 100 °C, viscosity index, flash point, presence of mineral acids and alkalis, mechanical impurities and water, acid number. The most often deviating from the standard of quality indicators of gasoline is the density, starting properties, the propensity to form in the summer of steam plugs in the power system. Sometimes this is accompanied by incompleteness of combustion. Diesel fuels are characterized by the following violations of standard quality indicators: high content of actual resins, reduced viscosity and very high (above 100 °C) flash point. The most common indicators of the quality of motor oils, the deviation from which can lead to a malfunction of the engine, are: viscosity at 100 °C, viscosity index, acid reaction, water availability, low flash point. After assessing the quality of motor oils, the most common causes of motor malfunction were identified. Most violations of the quality of oils are associated with its improper storage or deliberate mixing with cheaper components.

Substituent Effects of Organosilicon-Based Lithium-Ion Battery Electrolytes for Increased Thermal Stability

Electrolyte stability is one of the foremost challenges in improving the lifetime and operation of lithium-ion batteries. Despite their desirable high conductivity and solvation properties, conventional carbonate electrolytes have low flash points, low thermal stability, and limited electrochemical windows which give rise to significant safety and performance issues. Electrolyte degradation leads to the formation of problematic gaseous products and decomposition species that can trap lithium and increase cell impedance, leading to capacity fade. Silatronix, Inc, with the University of Wisconsin-Madison, has developed a novel class of electrolytes based on organosilicon solvents with decreased flammability, which have displayed enhanced electrochemical stability and reduced gassing. To understand the degradation mechanisms and structural components behind these improved properties, we report thermal, electrochemical, and hydrolytic stability studies of 4 organosilicon electrolytes with varying molecular substituents, and compare these organosilicons with conventional carbonate electrolytes. We identify and quantify thermal hydrolysis and electrochemical degradation electrolyte products via multinuclear NMR. We report insights into the manner by which different substituents affect electrolyte decomposition, and identify several mechanisms in organosilicon electrolytes that seem to inhibit degradation. Elucidation of the mechanisms of degradation for organosilicon electrolytes will help enable the design of future electrolytes with superior performance.

Comprehensive Assessment of Composition and Thermochemical Variability by High Resolution GC/QToF-MS and the Advanced Distillation-Curve Method as a Basis of Comparison for Reference Fuel Development.

Commercial and military aviation is faced with challenges that include high fuel costs, undesirable emissions, and supply chain insecurity that result from the reliance on petroleum-based feedstocks. The development of alternative gas turbine fuels from renewable resources will likely be part of addressing these issues. The United States has established a target for one billion gallons of renewable fuels to enter the supply chain by 2018. These alternative fuels will have to be very similar in properties, chemistry, and composition to existing fuels. To further this goal, the National Jet Fuel Combustion Program (a collaboration of multiple U.S. agencies under the auspices of the Federal Aviation Administration, FAA) is coordinating measurements on three reference gas turbine fuels to be used as a basis of comparison. These fuels are reference fuels with certain properties that are at the limits of experience. These fuels include a low viscosity, low flash point, high hydrogen content "best case" JP-8 (POSF 10264) fuel, a relatively high viscosity, high flash point, low hydrogen content "worst case" JP-5 (POSF 10259) fuel, and a Jet-A (POSF 10325) fuel with relatively average properties. A comprehensive speciation of these fuels is provided in this paper by use of high resolution gas chromatography/quadrupole time-of-flight - mass spectrometry (GC/QToF-MS), which affords unprecedented resolution and exact molecular formula capabilities. The volatility information as derived from the measurement of the advanced distillation curve temperatures, Tk and Th, provides an approximation of the vapor liquid equilibrium and examination of the composition channels provides detailed insight into thermochemical data. A comprehensive understanding of the compositional and thermophysical data of gas turbine fuels is required not only for comparison but also for modeling of such complex mixtures, which will, in turn, aid in the development of new fuels with the goals of diversified feedstocks, decreased pollution, and increased efficiency.

Anodic Activity of Pt and PtRu Catalysts on Ta-Doped SnO2 Supports for Direct-Fuel Fuel Cells Using a New Energy Carrier

Polymer electrolyte fuel cells (PEFCs) directly fueled liquid fuels are suitable power source for portable energy applications. Liquid alcohol fuels such as methanol and ethanol are attractive energy carriers with good energy density and low cost. However, the problems of their low flash points (below room temperature) and/or toxicity should be overcome for the safe application of alcohol-fueled PEFCs. The liquid oligomers of poly oxymethylene dimethyl ether (POMMn: CH3-O-(CH2-O)n-CH3, n = 3~8) have been proposed as alternative fuels, due to their advantages, including their higher energy density, lower toxicity and higher flash point1-3). In this study, we synthesized Pt and PtRu catalysts supported on Ta-SnO2 (Pt/Ta-SnO2, PtRu/Ta-SnO2) for the direct oxidation of POMM and evaluated their performance in a PEFC. The Ta-SnO2 support4) was synthesized by the flame spray synthesis method. The oxide supports obtained were nanometer-sized particles with a carbon-like fused-aggregate structure. Pt and PtRu catalysts were loaded on the Ta-SnO2 by the colloidal method. The Pt/Ta-SnO2 (Pt loading amount, 14.0 wt%; particle size, 6.3 nm) and PtRu/Ta-SnO2 (Pt/Ru loading amount, 6.3/3.5 wt%; particle size, 2.2 nm) were obtained after heat treatment. The Pt and PtRu particles were highly dispersed on the Ta-SnO2 support. As shown in the high-angle annular dark-field STEM (HAADF-STEM) image and STEM-EDX line profile, Sn metal diffused into the Pt catalysts with the sintering process. X-ray photoemission spectroscopic (XPS) Sn 3d5/2 spectra for each catalyst indicated that part of the Sn was converted from Sn4+ to Sn0. We concluded that the catalysts formed binary Pt-Sn and ternary Pt-Ru-Sn alloys during the sintering procedure (Fig. 1). The onset potential for POMM2 oxidation on PtRu/Ta-SnO2, which was measured by a half-cell with a rotating disk electrode (RDE), was 0.3 V less positive than that of a commercial Pt2Ru3/CB catalyst (Fig. 2). The mass activity for POMM2 oxidation of PtRu/Ta-SnO2 at 0.5 V was also 3.5 times higher than that for a commercial Pt2Ru3/CB catalyst. The anodic activity of Pt/Ta-SnO2 was also higher than that of the commercial catalyst, by a factor of 2. The electrochemical performances of these anode catalysts were also evaluated by the use of membrane-electrode assemblies (MEAs, NRE117 membrane, commercial Pt/CB(TEC10E50E) 0.5 ± 0.025 mgPt cm2 cathode, Pt/Ta-SnO2 or PtRu/Ta-SnO2 0.25 or 0.27 mgPt cm2 anode, Fig. 3). The current densities of the MEAs using the Pt/Ta-SnO2 and PtRu/Ta-SnO2 catalysts as the anodes and Pt/CB as the cathode (POMM2 simulated fuel, O2 oxidant, 80oC operation temperature) were more than 10 times higher than that using the commercial Pt2Ru3/CB anode. The current density at 0.6 V for formaldehyde fuel supplied to an MEA applying the Pt/Ta-SnO2anode was 15 times higher than that for the commercial anode, even though the performance for methanol remained at the same level. We consider that the Sn on the surface of the Pt catalyst may suppress CO poisoning by weakening the adsorption strength of CO formed during the fuel oxidation processes, even at such low potentials as 0.2 to 0.4 V, and directly accelerate the oxidation of carbon monoxide at more positive potentials by a bifunctional mechanism, similar to that for Pt-Ru catalysts. Acknowledgements This work was partially supported by funds for the A-STEP project from the Japan Science and Technology Agency (JST), JSPS KAKENHI (B24350093) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), and the SPer-FC project from the New Energy and Industrial Technology Development Organization (NEDO) of Japan. References 1) D. Devaux, H. Yano, H. Uchida, J.L. Dubois, M. Watanabe, Electrochim. Acta 56 (2011) 1460. 2) S. Baranton, H. Uchida, D.A. Tryk, J.L. Dubois, M. Watanabe, Electrochim. Acta 108 (2013) 350. 3) K. Kakinuma, I.T. Kim, Y. Senoo, H. Yano, M. Watanabe, and M. Uchida, ACS Appl. Mater. Interfaces, 6 (2014) 22138. 4) Y. Senoo, K. Taniguchi, K. Kakinuma, M. Uchida, H. Uchida, S. Deki, and M. Watanabe, Electrochem. Commun., 51 (2015) 37. Figure 1

A comparative study of methyl cyclohexanemethanol and methyl isobutyl carbinol as frother for coal flotation

Methyl isobutyl carbinol (MIBC), an aliphatic alcohol, is widely used as a frothing reagent in coal flotation but it has safety concerns owing to its low flash point (approximately 40°C). In the present work, we studied a cyclic alcohol, methyl cyclohexanemethanol (MCHM) with a high flash point (approximately 110°C) and compared its coal flotation performance with that of MIBC. A bottom-driven mechanical flotation cell and two coking coals of distinct floatability, namely A and B, were used. Collectorless flotation tests were carried out with process water for coal A. Flotation tests with diesel as collector at 50ppm were carried out with simulated process water (0.03M NaCl solution) and highly saline water (0.5M NaCl solution), respectively, for coal B. The flotation results showed that MCHM was an effective alternative to MIBC. The highly saline water produced sufficient frothing, obviating the necessity of adding MIBC or MCHM. To understand the effect of frother type and concentration and NaCl concentration on the coal flotation performance, we conducted surface tension measurement for the frother solutions, characterized the dispersion of air near bubble sparger, and measured the stabilities of froth, foam, and foam film. It was found that MCHM was more surface active and more capable of stabilizing froth and foam than MIBC. Foam film stability measured at a broad range of interface approach velocity followed a bell-shaped trend and at a given NaCl concentration, the observed peak foam film stability of 15ppm MCHM was higher than that of 15ppm MIBC. Increasing NaCl concentration from 0.03M to 0.5M had the effect of stabilizing the froth and foam but destabilising the thin foam film.

Case study on operating characteristics of gas fueled ship under the conditions of load variation

The use of gas as fuel, particularly liquefied natural gas (LNG), has increased in recent years owing to its lower sulfur and particulate emissions compared to fuel oil or marine diesel oil. LNG is a low temperature, volatile fuel with very low flash point. The major challenges of using LNG are related to fuel bunkering, storing, and handling during ship operation. The main components of an LNG fuel system are the bunkering equipment, fuel tanks, vaporizers/heaters, pressure build-up units (PBUs), and gas controlling units. Low-pressure dual-fuel (DF) engines are predominant in small LNG-powered vessels and have been operating in many small- and medium-sized ferries or LNG-fueled generators.(Tamura, K., 2010; Esoy, V., 2011[1][2]) Small ships sailing at coast or offshore rarely have continuous operation at constant engine load in contrast to large ships sailing in the ocean. This is because ship operators need to change the engine load frequently due to various obstacles and narrow channels. Therefore, controlling the overall system performance of a gas supply system during transient operations and decision of bunkering time under a very poor infrastructure condition is crucial. In this study, we analyzed the fuel consumption, the system stability, and the dynamic characteristics in supplying fuel gas for operating conditions with frequent engine load changes using a commercial analysis program. For the model ship, we selected the ‘Econuri’, Asia’s first LNG-powered vessel, which is now in operation at Incheon Port of South Korea.

Oxidation stability enhancement of a blend of mineral and synthetic ester oils

Mineral oils have been used in transformers for cooling and insulation for many years. Despite their long-time success, mineral oils are facing critiques by the electrical power industry in terms of thermal performance—mineral oils have relatively low flashpoint and fire point and will burn in the event of a fault [1], [2], [3]; environmental performance—mineral oils are less biodegradable, toxic in nature, and hazardous in the soil and water [4]; and risk assessment—mineral oils are imperilling near hospitals, near high rise buildings, and in residential areas.