Butane Oxidation Research Articles

Development of a Portable SOFC System with Internal Partial Oxidation Reforming of Butane and Steam Reforming of Ethanol

Internal partial oxidation reforming of butane and steam reforming of ethanol were investigated using microtubular solid oxide fuel cells (SOFCs) supported on nickel-gadolinia doped ceria (Ni-GDC) anode for portable power sources in an emergency situation and mobilities such as vehicles, robots and drones. At oxygen/carbon (O/C) ratio of 1.0, the Ni-GDC anode deteriorated for 28 h by internal partial oxidation of butane at 650 oC. Furthermore, power generation was also impossible after 8 and 79 h at steam/carbon (S/C) ratios of 1.0 and 1.5, respectively, by internal steam reforming of ethanol. Power can be generated over a period of more than 100 h at O/C = 1.5 in butane and at S/C = 2.0 in ethanol. We successfully demonstrated a prototype 100 W-scale portable SOFC system fueled by liquefied petroleum gas (LPG).

The TOMCAT global chemical transport model v1.6: description of chemical mechanism and model evaluation

Abstract. This paper documents the tropospheric chemical mechanism scheme used in the TOMCAT 3-D chemical transport model. The current scheme includes a more detailed representation of hydrocarbon chemistry than previously included in the model, with the inclusion of the emission and oxidation of ethene, propene, butane, toluene and monoterpenes. The model is evaluated against a range of surface, balloon, aircraft and satellite measurements. The model is generally able to capture the main spatial and seasonal features of high and low concentrations of carbon monoxide (CO), ozone (O3), volatile organic compounds (VOCs) and reactive nitrogen. However, model biases are found in some species, some of which are common to chemistry models and some that are specific to TOMCAT and warrant further investigation. The most notable of these biases are (1) a negative bias in Northern Hemisphere (NH) winter and spring CO and a positive bias in Southern Hemisphere (SH) CO throughout the year, (2) a positive bias in NH O3 in summer and a negative bias at high latitudes during SH winter and (3) a negative bias in NH winter C2 and C3 alkanes and alkenes. TOMCAT global mean tropospheric hydroxyl radical (OH) concentrations are higher than estimates inferred from observations of methyl chloroform but similar to, or lower than, multi-model mean concentrations reported in recent model intercomparison studies. TOMCAT shows peak OH concentrations in the tropical lower troposphere, unlike other models which show peak concentrations in the tropical upper troposphere. This is likely to affect the lifetime and transport of important trace gases and warrants further investigation.

The Effect of Using H4P2O7 as Phosphorus Source for Synthesizing Vanadyl Pyrophosphate Catalysts

<p>Vanadyl pyrophosphate (VO)<sub>2</sub>P<sub>2</sub>O<sub>7</sub> catalysts synthesized via VOPO<sub>4</sub>·2H<sub>2</sub>O were investigated by using BET surface area measurement, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Temperature-Programmed Techniques (TPD and TPRS). H<sub>3</sub>PO<sub>4</sub> and H<sub>4</sub>P<sub>2</sub>O<sub>7</sub> were used as the phosphorus source. Only pyrophosphate phase was observed for both final catalysts after 75 hours of calcination in a reaction flow of <em>n</em>-butane/air mixture (0.75% <em>n</em>-butane/air). However, catalyst derived from H<sub>4</sub>P<sub>2</sub>O<sub>7</sub> based preparation (denoted VPD<sub>pyro</sub>) exhibit better crystallinity and slightly higher BET surface area compared to the H<sub>3</sub>PO<sub>4</sub> based preparation (denoted VPD<sub>ortho</sub>). The nature of the oxidants for both catalysts was investigated by O<sub>2</sub>-TPD. For VPD<sub>pyro</sub>, TPD showed an oxygen peak maximum at 986 K and a shoulder at 1003 K, whereas for VPD<sub>ortho</sub>, the oxygen was desorbed as two peaks maxima at 966 and 994 K. The total amount of oxygen desorbed thermally from VPD<sub>pyro</sub> (3.60×10<sup>20</sup> atom×g<sup>-1</sup>) is higher than that obtained for VPD<sub>ortho</sub> (3.07×10<sup>20</sup> atom×g<sup>-1</sup>). VPD<sub>pyro</sub> displayed a slightly improved activity and selectivity for <em>n</em>-butane oxidation. A proper amount of V<sup>5+</sup> species may have an effect on the enhancement of the catalytic activity.</p>

A critical perspective on the design and development of metal oxide catalysts for selective propylene ammoxidation and oxidation

The objective of this article is to use the example of the development of metal oxide catalysts for the selective ammoxidation and oxidation of propylene to illustrate successful catalyst design strategies for achieving enhanced yields of acrylonitrile and acrolein, respectively. The processes of catalytic selective ammoxidation and oxidation of propylene are not the only, albeit they are among the most industrially significant, examples of the commercial application of metal oxide selective oxidation catalysts. Other important commercial catalytic processes that use highly developed metal oxide catalysts systems include butane oxidation to maleic anhydride and alkyl aromatic ammoxidation of toluene, xylenes, and picolines (alkyl pyridines) to produce valuable aromatic nitriles including nicotinonitrile which is the precursor for nicotinic acid (niacin) an important B-complex vitamin. Using the example of industrial propylene selective (amm)oxidation, this article surveys the available patents, scientific and technical journals to chronical and analyze the development and advancement of the complex metal oxides from discovery to current state-of-the-art. Recognizing that commercial practices are proprietary, this analysis uses no known company sensitive or confidential information is included in these descriptions. From this analysis a comprehensive catalyst design strategy unfolds that is based on the enabling science of solid state chemistry and the results of the characterization tools it provides. This provides a viable platform to unlock the next level of metal oxide catalyst development with ultra-high selectivity for hydrocarbon oxidation.

An extensive experimental and modeling study of 1-butene oxidation

In this study, a series of ignition delay time (IDT) experiments of 1-butene were performed in a high-pressure shock tube (HPST) and in a rapid compression machine (RCM) under conditions of relevance to practical combustors. This is the first 1-butene IDT data taken at engine relevant conditions, and the combination of HPST and RCM results greatly expands the range of data available for the oxidation of 1-butene to higher pressures (10–50atm), lower temperatures (670–1350K) and to a wide range of equivalence ratios (0.5–2.0).A comprehensive chemical kinetic mechanism to describe the combustion of 1-butene has simultaneously been applied. It has been validated using the IDT data measured here in addition to a large variety of literature data: IDTs, speciation data from jet-stirred reactor (JSR), premixed flame, and flow reactor, and laminar flame speed data. Important reactions have been identified via flux and sensitivity analyses including: (a) H-atom abstraction from 1-butene by hydroxyl radicals and molecular oxygen from different carbon sites; (b) addition reactions, including hydrogen atom and hydroxyl radical addition to 1-butene; (c) allylic radical chemistry, including the addition reactions with methyl radical, hydroperoxy radical and self-recombination; (d) vinylic radical chemistry, including the addition reaction with molecular oxygen; (e) alcohol radical chemistry, including the Waddington type propagating reaction pathways and alkyl radical low-temperature branching chemical pathways.

Thermophilic archaea activate butane via alkyl-coenzyme M formation

The anaerobic formation and oxidation of methane involve unique enzymatic mechanisms and cofactors, all of which are believed to be specific for C1-compounds. Here we show that an anaerobic thermophilic enrichment culture composed of dense consortia of archaea and bacteria apparently uses partly similar pathways to oxidize the C4 hydrocarbon butane. The archaea, proposed genus 'Candidatus Syntrophoarchaeum', show the characteristic autofluorescence of methanogens, and contain highly expressed genes encoding enzymes similar to methyl-coenzyme M reductase. We detect butyl-coenzyme M, indicating archaeal butane activation analogous to the first step in anaerobic methane oxidation. In addition, Ca. Syntrophoarchaeum expresses the genes encoding β-oxidation enzymes, carbon monoxide dehydrogenase and reversible C1 methanogenesis enzymes. This allows for the complete oxidation of butane. Reducing equivalents are seemingly channelled to HotSeep-1, a thermophilic sulfate-reducing partner bacterium known from the anaerobic oxidation of methane. Genes encoding 16S rRNA and methyl-coenzyme M reductase similar to those identifying Ca. Syntrophoarchaeum were repeatedly retrieved from marine subsurface sediments, suggesting that the presented activation mechanism is naturally widespread in the anaerobic oxidation of short-chain hydrocarbons.

The Nature of Synergetic Effect of Manganese Oxide and Platinum in Pt–MnOX–Alumina Oxidation Catalysts

The phase and chemical compositions, size and morphology of Pt particles, manganese oxides, and alumina in the binary Pt–MnOx–alumina catalysts have been studied and compared with Redox behaviors and catalytic properties in butane oxidation. X-ray diffraction, high-resolution transmission electron microscopy, and chemical differentiating dissolution were used for the catalysts characterization. Temperature-programmed reduction by hydrogen was employed to study the Redox properties. The catalyst Pt–MnOx–alumina has been shown to possess synergetic effects in the catalytic butane oxidation activity and reducibility by hydrogen as compared to alone Pt–alumina and MnOx–alumina samples. These effects were shown to be associated with modification of the imperfect Al3+-doped β-Mn3O4 nanoscale particles and the Mn3+-doped alumina crystals by platinum ions as well as the intimate contact of 1–2 nm sized PtO2 particles with β-Mn3O4 and manganese–alumina particles. It was found that Pt-precursors (such as H2PtCl6, H2[Pt(OH)6], Pt(NO2)2(NH3)2, [Pt(NH3)4]Cl2), alumina phase type (γ and χ) and temperature of the manganese–alumina activation (500 and 900 °C) had a strong effect on the unique properties of the Pt–MnOx–alumina in butane oxidation and its reducibility.

Syntrophic Interactions Within a Butane-Oxidizing Bacterial Consortium Isolated from Puguang Gas Field in China.

Butane oxidation by the hydrocarbon degradation bacteria has long been described, but little is known about the microbial interaction in this process. To investigate this interaction, the efficiency of butane oxidation was estimated in monocultures and co-cultures of six strains of butane-oxidizing bacteria (BOB) and a butanol-oxidizing strain. Results showed that the butane degradation velocity was at least 26 times higher in the co-culture of the seven strains (228.50nmolh(-1)) than in the six individual monocultures (8.71nmolh(-1)). Gas chromatographic analysis of metabolites in the cultures revealed the accumulation of butanol in the monocultures of BOB strains but not in the co-culture with the butanol-oxidizing strain. These results evidenced a novel syntrophic association between BOB and butanol-oxidizing bacteria in the butane oxidation. The BOB strains oxidized butane into butanol, but this activity was inhibited by the accumulated butanol in monocultures, whereas the removal of butanol by the butanol-oxidizing strain in co-culture could eliminate the suppression and improve the butane degradation efficiency. In the co-culture, both BOB and butanol-oxidizing bacteria could grow and the time needed for butane complete removal was shortened from more than 192h to less than 4h. The unsuppressed effect of the co-culture was also consistent with the results of reverse transcription quantitative real-time PCR (RT-qPCR) of bmoX gene because increased expression of this gene was detected during the syntrophic growth compared with that in monoculture, pointing to the upregulation of bmoX in the syntrophic interaction.

Highly dispersed Pt on B2O3/Al2O3 support: catalytic properties in the total oxidation of 1-butene

Applying a newly proposed method for the synthesis of a binary system Al2O3/B2O3, a series of metal phase supports with the ratio of B:Al components varied in the range from 0.05 to 1 was obtained. The supports were loaded with a metal phase from the water solution of H2PtCl6 to get the final load of 1 % of the metallic phase. The samples were subjected to thermal treatment under oxidizing or reducing conditions. The degree of dispersion of the metal phase, evaluated on the basis of hydrogen chemisorption, was very high, reaching a maximum of over 150 %. The catalytic performance of the catalysts was tested in the reaction of temperature-programmed complete oxidation of 1-butene.

Heterogeneous Partial (amm)Oxidation and Oxidative Dehydrogenation Catalysis on Mixed Metal Oxides

This paper presents an overview of heterogeneous partial (amm)oxidation and oxidative dehydrogenation (ODH) of hydrocarbons. The review has been voluntarily restricted to metal oxide-type catalysts, as the partial oxidation field is very broad and the number of catalysts is quite high. The main factors of solid catalysts for such reactions, designated by Grasselli as the “seven pillars”, and playing a determining role in catalytic properties, are considered to be, namely: isolation of active sites (known to be composed of ensembles of atoms), Me–O bond strength, crystalline structure, redox features, phase cooperation, multi-functionality and the nature of the surface oxygen species. Other important features and physical and chemical properties of solid catalysts, more or less related to the seven pillars, are also emphasized, including reaction sensitivity to metal oxide structure, epitaxial contact between an active phase and a second phase or its support, synergy effect between several phases, acid-base aspects, electron transfer ability, catalyst preparation and activation and reaction atmospheres, etc. Some examples are presented to illustrate the importance of these key factors. They include light alkanes (C1–C4) oxidation, ethane oxidation to ethylene and acetic acid on MoVTe(Sb)Nb-O and Nb doped NiO, propene oxidation to acrolein on BiMoCoFe-O systems, propane (amm)oxidation to (acrylonitrile) acrylic acid on MoVTe(Sb)Nb-O mixed oxides, butane oxidation to maleic anhydride on VPO: (VO)2P2O7-based catalyst, and isobutyric acid ODH to methacrylic acid on Fe hydroxyl phosphates. It is shown that active sites are composed of ensembles of atoms whose size and chemical composition depend on the reactants to be transformed (their chemical and size features) and the reaction mechanism, often of Mars and van Krevelen type. An important aspect is the fact that surface composition and surface crystalline structure vary with reaction on stream until reaching steady state, which makes characterisation of active and selective surface sites quite difficult. The use of oxidants other than O2, such as H2O2, N2O or CO2, is also briefly discussed. Based on such analysis and recent discoveries and process developments, our perspective is given.

Synergetic effect of Pd addition on catalytic behavior of monolithic platinum–manganese–alumina catalysts for diesel vehicle emission control

The advanced diesel emission control catalyst Pt–Pd–MnOx–Al2O3 has been developed on the basis of the synergetic effect of Pt with Pd and manganese oxides observed in hydrocarbon and carbon monoxide oxidation reactions. This effect allows a decrease in the total loadings of Pt and Pd down to 0.52g/L in the monolithic catalyst, providing high activity in low temperature oxidation of light hydrocarbons and high thermal stability.The catalytic activity of Pt–Pd–MnOx–Al2O3 monolithic catalysts in butane oxidation and DIESEL tests depends on the Pt and Pd precursors, their individual loadings and their ratio (Pt/Pd). For a selected Pt precursor at its content 0.17g/L, the catalytic performance of Pt–Pd–MnOx–Al2O3 catalyst improves with an increase in Pd loading from 0 to 0.35g/L and is nearly constant at a higher Pd loading (0.70g/L). The most active monolithic Pt–Pd–MnOx–Al2O3 catalyst is prepared by using platinum-dinitrodiamine and palladium nitrate solutions as noble metal precursors.The catalytic activity in light hydrocarbon oxidation is shown to correlate with the RedOx properties of PdPt–MnOx–Al2O3 catalysts and the Pt–Pd particle size. The non-additive increase in the catalytic activity of bimetallic catalyst is suggested to connect with a formation of nanoscale PdO–PtOx particles on the surface of Mn3O4 and a modification of alumina structure by Mn3+ and PtPd clusters.

Development of a ReaxFF Reactive Force Field for Fe/Cr/O/S and Application to Oxidation of Butane over a Pyrite-Covered Cr2O3 Catalyst

We developed a ReaxFF force field for Fe/Cr/O/S, which is parametrized against data from quantum mechanical (QM) calculations. Using this force field, we studied the Cr-oxide catalyzed oxidation reaction of butane at 1600 K. Our simulation results demonstrate that the active oxygen species on the oxide surface play an important role in the conversion of butane. Dehydrogenation of butane, which is found to be catalyzed by oxygen species on the oxide surface, initiates the reaction and generates butane radicals and surface OH groups. The radical intermediates are associated with the oxygen atoms to form C–O bonds or make double bonds when neighboring carbon atoms are dehydrogenated, forming light alkenes. On the clean Cr-oxide, the major oxidation product is CH2O. The presence of iron pyrite (FeS2), a common inorganic component in coal-derived fuels and a major slagging component, on Cr-oxide accelerates the complete oxidation of butane forming CO2 and CO. Surface reconstruction by iron pyrite is probably r...

A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol.

We investigated the synthesis of maleic anhydride by oxidehydration of a bio-alcohol, 1-butanol, as a possible alternative to the classical process of n-butane oxidation. A vanadyl pyrophosphate catalyst was used to explore the one-pot reaction, which involved two sequential steps: 1) 1-butanol dehydration to 1-butene, catalysed by acid sites, and 2) the oxidation of butenes to maleic anhydride, catalysed by redox sites. A non-negligible amount of phthalic anhydride was also formed. The effect of different experimental parameters was investigated with chemically sourced 1-butanol, and the results were then confirmed by using genuinely bio-sourced 1-butanol. In the case of bio-1-butanol, however, the purity of the product remarkably affected the yield of maleic anhydride. It was found that the reaction mechanism includes the oxidation of butenes to crotonaldehyde and the oxidation of the latter to either furan or maleic acid, both of which are transformed to produce maleic anhydride.

A high pressure shock tube study of 1-butene oxidation and its comparison with n -butane and alkenes

Ignition delay times of 1-butene were measured behind reflected shock wave at the pressures of 1.2, 4.0, 16.0 atm, in temperature range of 1000–1700 K and equivalence ratios of 0.5, 1.0 and 2.0. Results show that ignition delay times exhibit the typical Arrhenius dependence on temperature, pressure, equivalence ratio and fuel concentration. A correlation was deduced from the experimental data. Comparison was made between the correlation and the previous data, and good agreement was achieved. Three widely used models, NUIG Aramco Mech 1.3 (Metcalfe et al., 2013), USC Mech 2.0 (Wang et al.) and LLNL C4 (Marinov et al., 1998) model, were used to predict the ignition delay times and comparison was made with the experimental data. None of these models can well reproduce the experimental data of 1-butene especially at lower temperature. Besides, comparative studies and qualitative analysis between C4 hydrocarbons and 1-alkenes with respect to the effect of CC bond and the carbon chain length were made at same argon–oxygen dilution ratios (D). Sensitivity analysis was made to identify the key reactions that control the ignition of 1-butene, and modifications for improving the model performance were recommended.

Marine microbes rapidly adapt to consume ethane, propane, and butane within the dissolved hydrocarbon plume of a natural seep

AbstractSimple hydrocarbon gases containing two to four carbons (ethane, propane, and butane) are among the most abundant compounds present in petroleum reservoirs, and are introduced into the ocean through natural seepage and industrial discharge. Yet little is known about the bacterial consumption of these compounds in ocean waters. To assess the timing by which microbes metabolize these gases, we conducted a three‐phase study that tested and applied a radiotracer‐based method to quantify the oxidation rates of ethane, propane, and butane in fresh seawater samples. Phase 1 involved the synthesis of tritiated ethane, propane, and butane using Grignard reagents and tritiated water. Phase 2 was a systematic assessment of experimental conditions, wherein the indigenous microbial community was found to rapidly oxidize ethane, propane, and butane. Phase 3 was the application of this tritium method near the Coal Oil Point seeps, offshore California. Spatial and temporal patterns of ethane, propane, and butane oxidation down current from the hydrocarbon seeps demonstrated that >99% of these gases are metabolized within 1.3 days following initial exposure. The oxidation of ethane outpaced oxidation of propane and butane with patterns indicating the microbial community responded to these gases by rapid adaptation or growth. Methane oxidation responded the slowest in plume waters. Estimates based on the observed metabolic rates and carbon mass balance suggest that ethane, propane, and butane‐consuming microorganisms may transiently account for a majority of the total microbial community in these impacted waters.

Tribute to Professor Genady E. Zaikov on the Occasion of his 80thBirthday

“In the first part of his life any scientist is working for his reputation, in the second part his reputation is working for him”. This is a typical sentence one can say about Professor Genady Zaikov, Chief Scientist of the N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia. On January 7, 2014, Professor Zaikov's 79th birthday, a colleague reminded him that the numeric value 79 is the number of the element gold (Aurum) in the Mendeleev periodic table of elements. The number 80 refers to mercury (Hydrargium), also a very valuable metal, because of its active movement. This is what Professor Zaikov still does, in spite of his excellent reputation, gained over more than 50 years in science. On February 13, 1957, Genady started working at the Institute of Chemical Physics, Academy of Sciences of the USSR. He had the chance to begin his career in the laboratory of Professor Nikolai Markovich Emanuel, a well-known scientist in the field of chemical kinetics. During his first meeting, Emanuel asked him about his areas of expertise, and Genady answered: I know chemical kinetics, I am able to separate isotopes, and I also play the saxophone. Based on this, Emanuel invited him as a researcher to his laboratory, and also asked him to organize a jazz-band, which performed in the institute every weekend. On January 4, 1964, Genady defended his PhD thesis “The comparison of processes of butane oxidation in liquid and gas phases”. Based on these results, a plant was constructed to produce butane oxidation to acetic acid and metylethylketone, with a capacity of 10 thousand tons of acetic acid, at a Moscow oil-processing plant. His Doctor of Science thesis “Role of Media in the Radical Chain Reactions of Oxidation” was defended on April 16, 1968 and on May 20, 1968, he went to Canada (National Research Council of Canada, Ottawa) to work with Professor Keith Usherwood Ingold. After that he worked in the USA, the UK, Japan, and Germany for some time. In 1970, Genady became a Full Professor of Chemistry. Shortly after, his first book with the co-authors N. M. Emanuel and Z. K. Maizus was published in 1973 on the basis of the same research as his Doctor of Science thesis. This book was translated into English and published by Pergamon Press (Oxford, UK). To date, Professor Zaikov (with many co-authors) has published more than 400 monographs and volumes (about 300 in English and about 100 in Russian) and about 4,000 original articles in Russian and in English. All of them are devoted to chemical physics, chemical kinetics, biochemical kinetics, biochemical physics, polymer material science, composites and nanocomposites. One of his fields of expertise was the “degradation and stabilization of polymers”. Professor Zaikov also gained a good reputation in the area of flame retardancy of polymeric materials. During his career, he met many great scientists including Herman F. Mark, Austrian-US-American chemist, considered as one of the major founders of modern polymer physics. Professor Zaikov is still active as a professor at various Russian universities and as chief scientist at the Russian Academy of Sciences, gives many interesting lectures on international conferences, like the “Times of Polymers and Composites” (TOP) conference on the island of Ischia, Italy, 2014 (Figure 1), and will do this definitely also beyond his 80th birthday on January 7, 2015. For this I congratulate him very much and wish him good health for many more years in the field of polymer science.

Shape-dependent plasma-catalytic activity of ZnO nanomaterials coated on porous ceramic membrane for oxidation of butane

In order to explore the effects of the shape of ZnO nanomaterials on the plasma-catalytic decomposition of butane and the distribution of byproducts, three types of ZnO nanomaterials (nanoparticles (NPs), nanorods (NRs) and nanowires (NWs)) were prepared and coated on multi-channel porous alumina ceramic membrane. The structures and morphologies of the nanomaterials were confirmed by X-ray diffraction method and scanning electron microscopy. The observed catalytic activity of ZnO in the oxidative decomposition of butane was strongly shape-dependent. It was found that the ZnO NWs exhibited higher catalytic activity than the other nanomaterials and could completely oxidize butane into carbon oxides (COx). When using the bare or ZnO NPs-coated ceramic membrane, several unwanted partial oxidation and decomposition products like acetaldehyde, acetylene, methane and propane were identified during the decomposition of butane. When the ZnO NWs- or ZnO NRs-coated membrane was used, however, the formation of such unwanted byproducts except methane was completely avoided, and full conversion into COx was achieved. Better carbon balance and COx selectivity were obtained with the ZnO NWs and NRs than with the NPs.

Application of geo-microbial prospecting method for finding oil and gas reservoirs

Microbial prospecting of hydrocarbons is based on the detection of anomalous population of hydrocarbon oxidizing bacteria in the surface soils, indicates the presence of subsurface oil and gas accumulation. The technique is based on the seepage of light hydrocarbon gases such as C1–C4 from the oil and gas pools to the shallow surface that provide the suitable conditions for the development of highly specialized bacterial population. These bacteria utilize hydrocarbon gases as their only food source and are found enriched in the near surface soils above the hydrocarbon bearing structures. The methodology involves the collection of soil samples from the survey area, packing, preservation and storage of samples in pre-sterilized sample bags under aseptic and cold conditions till analysis and isolation and enumeration of hydrocarbon utilizing bacteria such as methane, ethane, propane, and butane oxidizers. The contour maps for the population density of hydrocarbon oxidizing bacteria are drawn and the data can be integrated with geological, geochemical, geophysical methods to evaluate the hydrocarbon prospect of an area and to prioritize the drilling locations thereby reducing the drilling risks and achieve higher success in petroleum exploration. Microbial Prospecting for Oil and Gas (MPOG) method success rate has been reported to be 90%. The paper presents details of microbial prospecting for oil and gas studies, excellent methodology, future development trends, scope, results of study area, case studies and advantages.

Physics of the multi-functionality of lanthanum ferrite ceramics

In the present work, we have illustrated the physics of the multifunctional characteristics of nano-crystalline LaFeO3 powder prepared using auto-combustion synthesis. The synthesized powders were phase pure and crystallized into centro-symmetric Pnma space group. The temperature dependence of dielectric constant of pure LaFeO3 exhibits dielectric maxima similar to that observed in ferroelectric ceramics with non-centrosymmetric point group. The dielectric relaxation of LaFeO3 correlates well with small polaron conduction. The occurrence of polarization hysteresis in LaFeO3 (with centro-symmetric Pnma space group) is thought to be spin current induced type. The canting of the Fe3+ spins induce weak ferromagnetism in nano-crystalline LaFeO3. Room temperature saturation magnetization of pure LaFeO3 is reported to be 3.0 emu/g. Due to the presence of both ferromagnetic as well as polarization ordering, LaFeO3 behaves like a single phase multiferroic ceramics. The magneto-electric coupling in this system has been demonstrated through the magneto-dielectric measurements which yield about 0.8% dielectric tuning (at 10 kHz) with the application of 2 T magnetic field. As a typical application of the synthesized nano-crystalline LaFeO3 powder, we have studied its butane sensing characteristics. The efficient butane sensing characteristics have been correlated to their catalytic activity towards oxidation of butane. Through X-ray photoelectron spectroscopy analyses, we detect the surface adsorbed oxygen species on LaFeO3 surface. Surface adsorbed oxygen species play major role in their low temperature butane sensing. Finally, we have hypothesized that the desorbed H2O and O2 (originate from surface adsorbed hydroxyl and oxygen) initiate the catalytic oxidative dehydrogenation of n-butane resulting in weakening of the electrostatics of the gas molecules.

Photocatalytic oxidation of butane by titania after reductive annealing

Highly photoactive anatase and rutile modifications of titania were prepared by annealing the product of thermal hydrolysis of titania peroxo-complexes under different atmosphere (hydrogen, nitrogen, and oxygen) at 950 °C. The prepared samples were characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, electron spin resonance, scanning electron microscopy, and Brunauer–Emmett–Teller surface area and porosity measurement. The individual samples differ with phase composition (ratio of anatase and rutile) and color that determines the rate of reduction of TiO2 and is for reduced form of TiO2 characterized. The UV/Vis diffuse reflectance spectroscopy was employed to estimate band-gap energies. Annealed samples were deposited as a 300 μm thick layer on a glass plate (10 cm × 15 cm) for assessment of the kinetics of a photocatalytic degradation of butane in a gas phase.