Moderate Sulfur Research Articles

Synergistic Electrocatalyst-Cathode Architecture for Stable Long-Term Cycling Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries are a promising candidate for next-generation energy storage owing to the high theoretical capacity of sulfur (1,675 mAh g−1). However, the intrinsically low electrical conductivity of sulfur and complex multistep electrolyte-mediated redox reactions involving soluble lithium polysulfide intermediates engender critical challenges toward practical realization. Specifically, migration and diffusion of higher-order lithium polysulfides provokes continuous loss of active sulfur species, yielding premature capacity fade. Electrochemical kinetics also remain sluggish due to the insulating nature of sulfur cathodes, which require engineering designs to accelerate charge transfer.Rational morphological and compositional cathode tuning represents a compelling strategy for addressing fundamental Li-S limitations. Herein, we develop an extended cathode architecture composed of a porous carbon nanotube network decorated with homogenously dispersed nanocatalysts. Electron microscopy and spectroscopy analysis verify platinum group metals are well-incorporated both within internal channels and external surface sites of conductive carbon nanotubes. The composite framework affords multifaceted functionality arising from synergistic chemical and structural attributes of components. Nanocatalyst sites demonstrate a pronounced chemical affinity toward soluble polysulfide intermediates, effectively localizing them within cathode, minimizing diffusional losses toward the anode. This anchoring phenomenon is complemented by the inherent microporosity of the high-surface-area nanotube network, further obstructing polysulfide migration through a confinement effects. Concurrently, noble metal nanoparticles facilitate the redox conversion of trapped higher-order polysulfides into solid Li2S alleviating the precipitation of electrically insulating discharge products. The excellent electrical conductivity of CNTs ensures efficient charge transport to all incorporated sulfur active materials, further maximizing reversible utilization.As a result of complementary polysulfide confinement and electrocatalytic conversion functionalities, Li-S coin cells exhibit enhanced reversible capacities exceeding 900 mAh g−1 for over 500 cycles at 0.558 A g−1. Notably, over 500 cycles, minimal capacity decay of 0.018% per cycle and 92% retention of the initial capacity are obtained at moderate sulfur loadings highlighting the exceptional cycling stability enabled by engineered cathodes. Outstanding rate performance is also demonstrated with the delivery of 854 mAh g−1 capacity at a very high current density of 1.675 A g−1. Our rationally designed cathode architecture provides critical mechanistic insight toward addressing fundamental bottlenecks to progress Li-S technologies.

PDRs4All

Context. One of the main problems in astrochemistry is determining the amount of sulfur in volatiles and refractories in the interstellar medium. The detection of the main sulfur reservoirs (icy H2S and atomic gas) has been challenging, and estimates are based on the reliability of models to account for the abundances of species containing less than 1% of the total sulfur. The high sensitivity of the James Webb Space Telescope provides an unprecedented opportunity to estimate the sulfur abundance through the observation of the [S I] 25.249 µm line. Aims. Our aim is to determine the amount of sulfur in the ionized and warm molecular phases toward the Orion Bar as a template to investigate sulfur depletion in the transition between the ionized gas and the molecular cloud in HII regions. Methods. We used the [S III] 18.7 µm, [S IV] 10.5 µm, and [S l] 25.249 µm lines to estimate the amount of sulfur in the ionized and molecular gas along the Orion Bar. For the theoretical part, we used an upgraded version of the Meudon photodissociation region (PDR) code to model the observations. New inelastic collision rates of neutral atomic sulfur with ortho-and para- molecular hydrogen were calculated to predict the line intensities. Results. The [S III] 18.7 µm and [S IV] 10.5 µm lines are detected over the imaged region with a shallow increase (by a factor of 4) toward the HII region. This suggests that their emissions are partially coming from the Orion Veil. We estimate a moderate sulfur depletion, by a factor of ~2, in the ionized gas. The corrugated interface between the molecular and atomic phases gives rise to several edge-on dissociation fronts we refer to as DF1, DF2, and DF3. The [S l] 25.249 µm line is only detected toward DF2 and DF3, the dissociation fronts located farthest from the HII region. This is the first ever detection of the [S l] 25.249 µm line in a PDR. The detailed modeling of DF3 using the Meudon PDR code shows that the emission of the [S l] 25.249 µm line is coming from warm (>40 K) molecular gas located at AV ~1–5 mag from the ionization front. Moreover, the intensity of the [S l] 25.249 µm line is only accounted for if we assume the presence of undepleted sulfur. Conclusions. Our data show that sulfur remains undepleted along the ionic, atomic, and molecular gas in the Orion Bar. This is consistent with recent findings that suggest that sulfur depletion is low in massive star-forming regions because of the interaction of the UV photons coming from the newly formed stars with the interstellar matter.

Paleovegetation and environment during deposition of the Late Oligocene sub-bituminous coal in the Bobov Dol Basin (SW Bulgaria) as deduced from petrographic and geochemical characteristics

Coal and carbonaceous shale samples were taken from the Late Oligocene Bobov Dol Basin, SW Bulgaria. Seams Ia, I, IIa+b, III, IV and V from the coal-bearing Bobov Dol Fm. were sampled to provide insights into the peat forming vegetation and depositional environment based on detailed organic petrological and geochemical study.The petrographic composition indicates that both coals and carbonaceous shales contain predominantly terrestrial organic matter with abundant huminite macerals and locally enriched liptinite macerals. Inertinite is rare or absent. Good tissue preservation in seams I, IV and V indicates deposition under wet sedimentary environment, whereas predominance of detrohuminite and lower Tissue Preservation Index (TPI) in seams Ia, IIa+b and III are linked to enhanced humification of the plant remains due to changes in the hydrological regime. The low percent of inertinite and the overall high Gelification Index (GI), however, argue for peat formation under wetter climatic settings, whereas low to moderate ash yields of coal samples indicate organic matter deposition in oligo- to mesotrophic topogenous mires. Reconstructed evolution of the environmental settings during peat formation denotes differences which might be caused by changes in the hydrological regime and tectonic activity.The biomarker composition shows prevalence of gymnosperm-derived sesqui- and diterpenoids, followed by lower concentration of n-alkanes (apart from the carbonaceous shale samples from seam Ia), whereas angiosperm-derived non-hopanoid triterpenoids, acyclic isoprenoids, steroids and hopanoids, are generally present in minor amounts. Diterpenoid composition indicates dominant contribution from Cupressaceae and Pinaceae conifers. Minor amounts of predominantly lupane-type non-hopanoid triterpenoids denote limited development of angiosperm vegetation, presumably mostly related to Betulaceae family. Relative abundance of mid-chain (n-C21–25) n-alkanes, associated with elevated proxy ratio (Paq) furthermore, suggest possible contribution from aquatic macrophytes to peat formation. Very low hopane concentrations and low/moderate ββ/(ββ + αβ) hopane ratios imply minor aerobic bacterial activity under mild acidic conditions. The presence of inorganic carbon suggests that environmental acidity might be controlled by the occasional input of neutral to slightly alkaline ground waters. Moderate sulfur contents and the occurrence of hopenes denote anaerobic bacterial activity after organic matter burial.Low maturity of the organic matter and limited hydrocarbon generation potential is indicated by the low huminite reflectance, hopane (C31 22S/(22S + 22R)) and sterane (αααC29 20S/(20S + 20R)) isomerization ratios, as well as Rock-Eval parameters, Tmax and Production Index (PI).

CORROSION RESISTANCE OF POWDER COATING WITH USE OF FERRITIZATION WASTE

Aspects for increasing the corrosion resistance of powder coating materials as a result of the involvement of the latest technologies for cleaning electroplating production waste are considered. The results of the effect of ferritization waste on the formation of corrosion resistance of coatings based on powder coating are shown. The introduction of the obtained ferritization waste into the composition of powder coating systems has a different effect on the formation of corrosion resistance of coatings was found. Thus, the control composition of the powder coating using a filler in the form of barium sulfate during 480 hours of exposure in the salt fog chamber is characterized by peeling of the coating at the level of 7.5 mm. The average width of metal corrosion is 5.5 mm. The category of corrosion resistance of the coating corresponds to class C3 (average) with the provision of an average durability class (M) from 7 to 15 years. Examples of typical environments (according to DSTU ISO 12944-2:2019) where the resulting coatings can be used are urban and industrial atmospheres, moderate sulfur dioxide pollution, coastal areas with low salinity. The use of galvanic waste sediments in general contributes to increasing the corrosion resistance of the powder coating. The efficiency of their use depends on the chemical composition of ferritization waste. Among the studied samples, the most effective is the introduction of waste in the form of Ni0.5Cu0.5Fe2O4 and Zn0.5Cu0.5Fe2O4 into the composition of powder systems, which helps to reduce the width of coating peeling by 65...79 %, as well as the width of metal corrosion by 75...80 % compared to the control composition. The least effective among the studied samples is the use of waste in the form of Ni0.5Zn0.5Al0.15Fe1.85O4 and CrFe2O4 due to a significant decrease in the corrosion resistance of the powder coating Powder coating systems were obtained using ferritization waste, the category of corrosion resistance of which corresponds to class C4 (high) with a high durability class (H) from 15 to 25 years. In general, the use of ferritization waste provides better corrosion resistance of coatings compared to traditional systems based on barium sulfate, which in turn gives reason to consider such systems as an alternative for corrosion protection of construction metal products and structures.

Organic geochemical studies and origin of black hydrocarbon material (heavy oil) produced from Risha gas field (Jordon): insights into produced contaminated organic-inorganic materials during production

After several years of gas production, a black solid hydrocarbon material began to be produced along with the gas stream from the Risha gas field, in the northeastern part of Jordan. The main reason for the formation of this material is still unknown until this time, so knowing the source of this material is this study’s main goal. Organic geochemical studies for black solid material and effective source rocks (Lower Silurian shales) are used to determine the physical and organic components of the produced black solid material (heavy oil) and attempt to identify its source. The black solid material demonstrates high organic carbon (TOC = 12% by leco instrument) and a high calorific value, like those of oils, asphalts, and shale oils with moderate sulfur content. The gross composition of the black solid material sample is dominated by saturates and asphaltene but contains very low aromatic hydrocarbons reflecting the naphthenic oil type. Meanwhile, the Silurian extracts range between paraffinic and paraffinic-naphthenic organic matters. The biomarker indicators related depositional environment and carbon isotopic composition for the black solid material sample and Silurian extracts, show that they were relatively deposited in a reducing marine environment. The black material reveals lower maturity level than the Silurian extracts. Oil/source rock correlation study for the studied samples suggests strong affinity between the black material and Lower Silurian source rock in their source characteristics, suggesting that the black hydrocarbon material was expelled from the Silurian source rocks at low maturity stage as normal oil. This normal oil is subjected to secondary alteration process (evaporative fractionation) and was stored in the reservoir. It contaminated with some inorganic material that was introduced into the well as a component of a drilling mud additive or drill string lubricant or, potentially, in part, a corrosion product of wellbore tubulars, since significant iron was present in the sample.

Enhanced Tribological Performance of Low-Friction Nanocomposite WSexSy/NP-W Coatings Prepared by Reactive PLD

A novel laser-based method for producing nanocomposite coatings consisting of a tungsten sulfoselenide (WSexSy) matrix and W nanoparticles (NP-W) was developed. Pulsed laser ablation of WSe2 was carried out in H2S gas under appropriate laser fluence and reactive gas pressure. It was found that moderate sulfur doping (S/Se ~0.2-0.3) leads to significant improvement in the tribological properties of WSexSy/NP-W coatings at room temperature. Changes in the coatings during tribotesting depended on the load on the counter body. The lowest coefficient of friction (~0.02) with a high wear resistance was observed in a N2 environment at an increased load (5 N), resulting from certain structural and chemical changes in the coatings. A tribofilm with a layered atomic packing was observed in the surface layer of the coating. The incorporation of nanoparticles into the coating increased its hardness, which may have influenced the formation of the tribofilm. The initial matrix composition, which had a higher content of chalcogen atoms ((Se + S)/W~2.6-3.5), was altered in the tribofilm to a composition close to the stoichiometric one ((Se + S)/W~1.9). W nanoparticles were ground and retained under the tribofilm, which impacted the effective contact area with the counter body. Changes in the tribotesting conditions-lowering the temperature in a N2 environment-resulted in considerable deterioration of the tribological properties of these coatings. Only coating with a higher S content that was obtained at increased H2S pressure exhibited remarkable wear resistance and a low coefficient of friction, measuring 0.06, even under complicated conditions.

Sulfur deficiency exacerbates phytotoxicity and residues of imidacloprid through suppression of thiol-dependent detoxification in lettuce seedlings

Sulfur, an essential macronutrient, plays important roles in plant development and stress mitigation. Sulfur deficiency, a common problem in agricultural soils, may disturb plant stress resistance and xenobiotic detoxification. In the present study, the function and mechanism of limited sulfur nutrition on the residues and phtotoxicity of imidacloprid were investigated in lettuce plants. Sulfur deficiency significantly increased imidacloprid accumulation in lettuce tissues, exacerbated imidacloprid biological toxicity by enhancing the accumulation of toxic metabolites, like imidacloprid-olefin. Simultaneously, imidacloprid-induced detoxification enzymes including cytochromes P450, glutathione S-transferases (GSTs) and glycosyltransferases were inhibited under limited sulfur supply. On the other hand, sulfur deficiency further enhanced the generation of reactive oxygen species and exacerbated lipid peroxidation in lettuce tissues. Sulfur deficiency mainly reduced the abundance of thiol groups, which are essential redox modulators as well as xenobiotic conjugators, and significantly inhibited GSTs expression. These results clearly suggested that sulfur deficiency inhibited the synthesis of sulfur-containing compounds, leading to increased accumulation of pesticide residues and toxic metabolites as well as reduced detoxification capacity, consequently leading to oxidative damage to plants. Therefore, moderate sulfur supply in regions where neonicotinoid insecticides are intensively and indiscriminately used may be an efficient strategy to reduce pesticide residues and the potential risk to ecosystem.

Recycling spent mushroom substrate into fuel pellets for low-emission bioenergy producing systems

This study aimed at analyzing the feasibility of converting diverse types of spent mushroom substrate (SMS) into fuel pellets for low-emission bioenergy producing systems. Sources of SMS for pelletization included paddy straw and achiote capsule shell from Pleurotus ostreatus, eucalyptus sawdust and grassy straw from Lentinula edodes, and compost with either peat or soil as a casing layer from Agaricus subrufescens. The pilot-scale manufacturing of fuel pellets consisted of compacting the feedstocks in an automatic pelletizer machine at 200 MPa and 125 °C. Pellets from SMS, irrespective of source, met the international standards for solid biofuels, except for ash content. However, due to moderate sulfur content (0.05%), they tended to low slagging (S < 0.60) and intermediate fouling (0.60 ≤ F ≤ 40.00) on a boiler's heating surface. Because of the significant ash content of 29.10–31.80%, these products resisted oxidation more at the onset of combustion, burned themselves out gradually and conducted 2.70–2.90 W g−1 heat at around 300 °C. Pellets of SMS from A. subrufescens grown on compost with soil casing, produced less heat (4.25 W g−1) than reference pellets from pinewood sawdust (5.10 W g−1), but emitted less CO2 (7.50 ppb vs 15.10 ppb), NOx (130.10 ppt vs 147.90 ppt), SO2 (3.15 ppt vs 16.70 ppt), and volatile organic compounds (17.65 mg m−3 vs 27.20 mg m−3). Pelletization of SMSs valorized these agro-food residues via waste-to-energy pathways towards a circular economy. SMS from A. subrufescens grown on compost with soil casing had the best properties for high-performance pelletization.

Effects of iron catalyst and atmosphere on sulfur transformation during pressurized low-temperature pyrolysis of Baishihu coal

A vitrinite-rich low rank coal, Baishihu (BSH) coal with moderate sulfur content was treated by dehydration and crushing. The treated samples were pyrolyzed in an alloy tubular reactor under 2 MPa. Influence of iron catalyst and atmosphere on sulfur transformation during pressurized low-temperature coal pyrolysis was investigated. Molecular composition of sulfur compounds in tar was characterized by gas chromatography with sulfur chemiluminescence detector (GC-SCD) combined with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Sulfur K-edge XANES was used to study sulfur molecular structure after pyrolysis. Sulfur compounds in BSH coal are predominantly S1 class species in branch chain of the coal. Elemental sulfur in catalyst enters the tar and forms mercaptan or thioether compounds during pyrolysis. Iron catalyst promotes activation of hydrogen atoms in coal and contributes to hydrogenation saturation and cracking of aromatic sulfide in tar. The catalyst preferentially captures H2S to increase content of pyrite in char and inhibits formation of sulfate. Under H2 atmosphere, significant decrease of thiophene compounds is observed with catalyst coupled with decrease of sulfoxide compounds.

Thermal state and solidification regime of the martian core: Insights from the melting behavior of FeNi-S at 20 GPa

A series of multi-anvil experiments have been conducted to define the iron-rich liquidus of the iron-nickel-sulfur (FeNi-S) system at 20 GPa, the estimated pressure of the martian core-mantle boundary (CMB). The liquidus curve of FeNi-S containing about 9 wt.% Ni has a concave up shape, and is as much as 400 K lower than the liquidi previously applied to the martian core with sparse experimental constraints. Unlike existing liquidi of Fe-S and FeNi-S at 23 GPa, which predict a fully molten core for a narrow range of sulfur content between 14 and 15 wt.% S, our results are consistent with a molten state for all proposed core compositions, and establishes a new minimum CMB temperature of 1500 K for 10 wt.% S and 1250 K for 16 wt.% S. Extrapolating our FeNi-S liquidus to high pressures and comparing it to calculated areotherms, we find that three core crystallization regimes are possible. For a martian core with moderate sulfur content (10 to 13 wt.%) or lower, crystallization takes the form of iron snow near the CMB, while for cores with higher sulfur content (15-16 wt.%), solidification occurs near the center of the planet in the form of solid Fe3S. At an intermediate sulfur content of 14 wt.%, Fe3S would precipitate over a broad depth range and may appear fully molten to surface observations.

Source rock kinetics and petroleum generation history of the Upper Ordovician calcareous shales of the Hudson Bay Basin and surrounding areas

The current understanding of the Paleozoic petroleum system in Hudson Bay Basin remains far from complete due in no small part to the uncertainty in locally-calibrated generation and migration models underpinned with reliable source rock kinetic data. To improve the petroleum systems model, four representative immature organic-rich calcareous shales of Late Ordovician age from onshore outcrops surrounding the Hudson Bay were analysed to characterize their source rock generation kinetics. To constrain uncertainty due to laboratory measurement errors in kinetic parameter estimation, six heating rates were used in the pyrolysis experiments for each sample, resulting in 24 kinetic datasets that reduce uncertainty from both source rock heterogeneity and inherited laboratory measurement errors. Under the assumed geological time and geothermal framework, application of the kinetic models resulted in internally consistent generation histories, suggesting that the source rock started to generate oil when temperature reached 100 °C. It is likely where the maximum burial depth excessed 3000 m, the source rocks were in oil generation window with kerogen transformation ratio varying in a range between 52 and 78%. The modeled source rock maturity range from the immature outcrop samples is supported by bulk rock geochemistry data from cuttings of the source rock interval in offshore wells with high S1 peaks, large humps on the left shoulder on S2 curves, typical feature of FID pyrograms in the oil window. Comparison of the kinetic behavior of the samples in this study with those of typical marine Type I, Type II and Type IIS source rocks under laboratory condition and the assumed geological time/temperature framework suggests that kerogen converts to oil in a lower temperature range than those typical normal marine Type II source rock. We attribute the moderate sulfur content (likely high sulfoxide/thiophene ratio) and presence of kerogen component groups that are more prone to cleavage at low temperature as the cause for low temperature onset of hydrocarbon generation.

Depositional history of low-mature coals from the Puyang Basin, Yunnan Province, China

Late Miocene samples from the Xiaolongtan Formation in Puyang Basin were sampled systematically from bottom to top of the main coal seam. Organic petrological as well as geochemical methods have been applied, aiming at the reconstruction of the depositional environment. The studied samples contain abundant detrovitrinite and liptinite macerals with high ash but low to moderate sulfur contents. This data indicates that the samples were deposited in topogenic mires without marine influence, but with fluctuations of water table and/or water influx which are mirrored by ash and sulfur content. The low values of tissue preservation and vegetation index, but high values of gelification index and groundwater index (GWIAC) in the studied coal imply a peat accumulation in inundated marshes under slightly oxic to anoxic depositional conditions with input of herbaceous plants mainly. An extended data set on vitrinite reflectance, volatile matter, Rock-Eval Tmax and HI suggests a coalification ranging from subbituminous C to B coal.The high concentration of long chain n-alkanes in the studied samples is typical for kerogen derived predominately from higher terrestrial plants. The applied biomarker ratios together with the detected hopenes further confirm the low thermal maturity level, as well as high water table and terrestrial organic matter input during peat accumulation. The variable concentrations of terpenoids and sesquiterpenoids suggest a dominant angiosperm input, but with a relatively high proportion of gymnosperms during some periods of peat deposition.

Leaching of coals with subcritical water

ABSTRACT The effects of subcritical water and organic acid additives on the leaching of three low-rank Turkish coals, Çan Tunçbilek, and Soma which have high ash and moderate sulfur contents were investigated. Test variables included temperature, pressure, and concentrations of organic acids. It was observed that temperature had a strong effect on the removal of ash and sulfur while pressure had a small effect. The best removal of sulfur was observed when organic acid solutions were used at 200°C and 70 atm. The best removal of ash was observed by using 1 M bortrifluorid (BF3) solution at 250°C and 70 atm. Depending on the leaching conditions and coal used, reductions ranged from 5% to 36% in sulfur and 5% to 59% in ash content.

Comparison of NOx Adsorption/Desorption Behaviors over Pd/CeO2 and Pd/SSZ-13 as Passive NOx Adsorbers for Cold Start Application

Passive NOx adsorber (PNA) is one of the promising technologies for reducing NOx emissions from vehicles during cold start periods. Precious metals supported on metal oxide and zeolite have been extensively investigated as PNA materials. Hence, it is worthwhile to compare two typical PNA materials, Pd/CeO2 and Pd/SSZ-13, so as to understand the differences between them. The NOx adsorption/desorption experiments were carried out under varying NO/NO2 ratios, and the result indicated that the NOx adsorption/desorption mechanisms on Pd/CeO2 and Pd/SSZ-13 are completely different. Specifically, NO and NO2 were competitively adsorbed on Pd/SSZ-13, while the NO adsorption on Pd/CeO2 was promoted by NO2. This difference is attributed to different adsorption sites: NOx is adsorbed on the ceria surface in Pd/CeO2, whereas it is adsorbed on atomic Pd2+ sites in Pd/SSZ-13, according to DRIFTS spectra in this study. In addition, the effect of sulfur poisoning was investigated as well. Pd/SSZ-13 showed moderate sulfur tolerance, while Pd/CeO2 completely lost its PNA ability after sulfur aging.

NiFe nanocatalysts for the hydrocracking heavy crude oil

In this work, NiFe nanocatalysts with different molar ratios 1:0.33, 1:1 and 1:3 were synthesized by a modified inverse microemulsion method at Soft Chemistry conditions in order to apply them to heavy crude oil (HCO) in situ hydroprocessing and to improve their physico-chemical properties. All samples were characterized by mean, atomic absorption (AA), small-angle X-ray scattering (SAXS), scanning transmission electron microscopy (STEM), X-ray energy dispersion spectroscopy (EDX), and X-ray photoelectron emission spectroscopy (XPS). Catalytic evaluation of nanocatalysts was performed in a batch reactor at 372 °C, 9.8 MPa of initial H2 pressure and 1 h of reaction time. The reaction products, were analyzed by means analysis of saturates, aromatics, resins, and asphaltenes (SARA) fractions, simulated distillation (SIMDIS), API gravity, rheology, and nitrogen and sulfur contents. Techniques applied reveal that nanoparticles of NiFe with spherical morphology with average sizes in the range (1–20) nm and agglomerates smaller than 50 nm were obtained. The nanocatalysts synthesized improved API gravity from 13.1 to 18.3, furthermore, the asphaltenes conversion was into 37.2–43.7%. Moderate sulfur and nitrogen removal was obtained. SARA analysis indicated that saturated and aromatics fractions increased while resins and asphaltenes were reduced.

Transition metal nanocatalysts by modified inverse microemulsion for the heavy crude oil upgrading at reservoir

Abstract In this work, nanocatalysts as Ni, Mo, Fe nanoparticles (NPs) were synthesized by the modified inverse microemulsion method at room temperature conditions in order to apply them to heavy crude oil (HCO) in situ hydroprocessing and to improve their physicochemical properties. All samples of NPs were characterized by X-ray photoelectron emission spectroscopy (XPS), X-ray energy dispersion spectroscopy (EDX), small-angle X-ray scattering (SAXS), and scanning transmission electron microscopy (STEM). Catalytic evaluation of nanocatalysts was performed in a batch reactor at 372 °C, 9.8 MPa of initial H2 pressure and 1 h of reaction time. The reaction products were studied by analysis of saturates, aromatics, resins, and asphaltenes (SARA) fractions, simulated distillation (SIMDIS), API gravity, and both nitrogen and sulfur contents to determine their physicochemical properties. Applied techniques revealed that nanoparticles of Ni, Mo, and Fe with spherical morphology with average sizes in the range (2.5–20) nm and agglomerates smaller than 50 nm were obtained. The nanocatalysts synthesized improved from 13 to 18°API, also of an asphaltenes conversion in the range 20–43%, and moderate sulfur and nitrogen removal were obtained. SARA analysis indicated that saturated and aromatics fractions increased while resins and asphaltenes were reduced, increasing the possibility of a high mobility of crude oil into the reservoir.

Characterization of Panandhro Lignite Deposits (Kachchh Basin), western India: Results from the Bulk Geochemical and Palynofloral Compositions

ABSTRACT Characterization of the Panandhro lignite deposits from western Indian state of Gujarat, based on the geochemical and palynological evidences, has been performed to assess the floral composition, maturity and hydrocarbon potential of the sequence. Elementally, the lignites consist of moderate carbon, low hydrogen and moderate sulfur contents. The samples are characterized by high TOC contents (lignite: av. 46.43 wt.%, resin: 62.47 wt.%). The average HI values for the lignite is 136 mg HC/g TOC, and that of the associated resin is 671 mg HC/g TOC. The highest Tmax is recoded in lignite (422°C) and lowest in the resin (39°C) samples. The FTIR spectrum of lignite is characterized by highly intense OH stretching peak ∼3350 cm–1, aliphatic CHx stretching peaks between 3000-2800 cm–1, aromatic C=O stretching and an aromatic C=C stretching. The spectrum of resin shows strongest absorption due to aliphatic CHx stretching between 2940-2915 cm–1 and 2870-2850 cm–1, and deformation by the medium peak between 1450 and 1650 cm–1. The recovered palynofloral assemblage indicates the dominance of angiosperm pollen grains with maximum abundance of Arecaceae family, and subdominant pteridophytic spores. Marine influence is indicated by the presence of abundant dinoflagellate cysts. The occurrence of flora from a variety of ecological niches suggests a luxuriant diverse vegetation pattern existed in the vicinity of depositional site under humid tropical conditions. The overall characteristics of the lignite deposits point towards their ability to generate (upon maturation) hydrocarbons as they have types III–II admixed kerogen (organic matters).

Genesis of soils from Holocene tidal deposits at the North Sea coast

The Southern North Sea coast has served as an exemplification to analyse and discuss the genesis of soils from Holocene tidal deposits. The accumulation wedge of Holocene tidal deposits at the North Sea coast is artificially embanked for the most part. In the enclosed area (hinterland) a variety of different soils developed. Disparate models attempting to explain the genesis of these soils deduce genesis of hinterland soils from recent foreland conditions, disregarding that geogenic preconditions have fundamentally changed. By consolidating and reviewing established literature we show that differences in geogenic preconditions are the initiating key for a feasible model. Describing geogenic preconditions to infer pedogenic processes, we develop a model comprising four different development pathways. High settling velocities and regular flooding, as present in the foreland, cause high inputs of mineral sediments and carbonate, moderate sulfur dynamics and thus the development of calcareous soils. Synsedimentary decalcification prevails in irregularly flooded areas due to enduring low sedimentation rates, low carbonate inputs and moderate sulfur dynamics under alternating redox states, as mainly proposed for the unobstructed landscape. High contents of soil organic matter (SOM) facilitate intensive sulfur dynamics creating potential acid sulfate soils (PASS), which become extreme acid upon oxidation (actual acid sulfate soils (AASS)). A great gradient in depositional conditions, occurring at unobstructed plain coasts, enables the deposition of deflocculated fine-grained sediments which promotes the formation of very compact soils with low water conductivities. Although this proposed model is based mainly on conditions known from the German North Sea coast, it is shown that shaping geogenic and pedogenic processes are applicable to other humid coastal regions around the world.

Source rock evaluation and organic geochemistry of Belayim Marine Oil Field, Gulf of Suez, Egypt

Geochemical evaluation of Belayim Marine Oil Field using TOC and Rock Eval Pyrolysis investigations for a total of 19 cutting samples (9 samples covering (Nubia-B Formation) from well BM-57, and 10 samples covering (Nubia-A, B Formations) from well BM-65) was performed. Furthermore, geochemistry analyses of two crude oil samples from Wells BM-29 and BM-70, which are recovered from the Upper Rudeis Formation were performed. The BM-70 oil sample is recovered by Drill Steam Testing, while the BM-29 oil sample is taken from the flow output. Moreover, the oil samples were subjected to GC/GC-MS analysis (Biomarker) by StratoChem Company.In general, TOC analyses showed that the Nubia-A and B formation sediments are fairly immature compared to good source rocks with very high Hydrogen Index indicative of kerogen type II. The geochemical investigations of two oil samples indicate that the Upper Rudeis oil of Belayim Marine was derived from a marine carbonate rich source, which is relatively rich in algal organic matter and has moderate sulfur content. The maturity of the analyzed oils (about 0.75% R0) falls short from the stage of peak hydrocarbon generation which is known to be reached at about 0.85% R0.

Activated oil sands fluid coke for electrical double-layer capacitors

Electrochemical capacitors are important energy storage devices that have high power density, rapid charging cycles and are highly cyclable. In this study, activated fluid coke has demonstrated high surface area, improved capacitive properties, and high energy density. Fluid coke is a by-product generated from continuous high temperature bitumen upgrading, resulting in the formation of nearly spherical particles with concentric carbon layers. The residual sulphur impurities in fluid coke may enhance its energy storage performance. The activated coke samples have high specific surface areas, up to 1960 m2 g−1, and show promising capacitive performance, in 4 M KOH electrolyte, with high gravimetric and specific capacitances of 228–257 F g−1 and 13–14 μF cm−2, respectively. These results are comparable to other top performing activated carbon materials [1–3]. The activated fluid coke maintains high performance at fast charging rates, greater than 160 F g−1 at a current density of 7500 mA g−1. Activated fluid coke's high capacitance and promising rate performance are potentially associated with its unique layered, and the moderate sulphur content in the chemical structure. Activated fluid coke is a unique opportunity to use a limited use by-product to generate activated carbon that has a high surface area and promising energy storage properties.