Decomposition Of Oil Research Articles

High-resolution GC/MS study of biodegradation of crude oil by Bacillus megaterium

Bacillus megaterium believed to be capable of crude oil degradation through the formation of the pure crude oil emulsion layer. This study was conducted during March 2019 to January 2020 at the Directorate of Environment and Water, Baghdad, Iraq to evaluate the bacterial biodegradation activity using Gas-Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). The visual GC-MS examination confirmed the disappearing trend of several chemicals, as well as decrease in the peak area for other components, indicating the efficiency of the bacteria in the oil decomposition and dismantling of hydrocarbons. The GC-MS analysis of crude oil treatment showed complete mineralization into low molecular weight compounds as Butanoic acid, 1-1-dimethylethyl ester, Benz [c] pyran-1,3-dione, 4,4-dimethyl, 1,2-Benezenedicarboxylic acid, diisooctyl ester, etc. Therefore, Bacillus megaterium can be effectively utilized for biodegradation of crude oil-contaminated soil and water ecosystems.

Integrated Omics Elucidate the Mechanisms Driving the Rapid Biodegradation of Deepwater Horizon Oil in Intertidal Sediments Undergoing Oxic-Anoxic Cycles.

Crude oil buried in intertidal sands may be exposed to alternating oxic and anoxic conditions but the effect of this tidally induced biogeochemical oscillation remains poorly understood, limiting the effectiveness of remediation and managing efforts after oil spills. Here, we used a combination of metatranscriptomics and genome-resolved metagenomics to study microbial activities in oil-contaminated sediments during oxic-anoxic cycles in laboratory chambers that closely emulated in situ conditions. Approximately 5-fold higher reductions in the total petroleum hydrocarbons were observed in the oxic as compared to the anoxic phases with a relatively constant ratio between aerobic and anaerobic oil decomposition rates even after prolonged anoxic conditions. Metatranscriptomics analysis indicated that the oxic phases promoted oil biodegradation in subsequent anoxic phases by microbially mediated reoxidation of alternative electron acceptors like sulfide and by providing degradation-limiting nitrogen through biological nitrogen fixation. Most population genomes reconstructed from the mesocosm samples represented uncultured taxa and were present typically as members of the rare biosphere in metagenomic data from uncontaminated field samples, implying that the intertidal communities are adapted to changes in redox conditions. Collectively, these results have important implications for enhancing oil spill remediation efforts in beach sands and coastal sediments and underscore the role of uncultured taxa in such efforts.

Catalytic Cracking of Heavy Crude Oil over Iron-Based Catalyst Obtained from Galvanic Industry Wastes

Sewage sludge from the galvanic industry represents a problem to the environment, due to its high metal content that makes it a hazardous waste and must be treated or disposed of properly. This study aimed to evaluate the sludge from three galvanic industries and determine its possible use as catalysts for the synthesis of materials. Catalyst was obtained from a thermal process based on dried between 100–120 °C and calcination of sludges between 400 to 700 °C. The physical–chemical properties of the catalyst were analyzed by several techniques as physisorption of N2 and chemisorption of CO of the material. Catalytic activity was analyzed by thermogravimetric analysis of a thermo-catalytic decomposition of crude oil. The best conditions for catalyst synthesis were calcination between 400 and 500 °C, the temperature of reduction between 750 and 850 °C for 15 min. The catalytic material had mainly Fe as active phase and the specific surface between 17.68–96.15 m2·g−1, the catalysts promote around 6% more weight-loss of crude oil in the thermal decomposition compared with assays without the catalyst. The results show that the residual sludge of galvanic industries after thermal treatment can be used as catalytic materials due to the easiness of synthesis procedures required, the low E-factor obtained and the recycling of industrial waste promoted.

Research into decomposition of hydrocarbons at restructured treatment facilities of Autodetail Open Joint Stock Company

Introduction. The novelty of the research is driven by the growing environmental contamination with anthropogenic substances, and in the course of accidents and emergency situations, as well as the need to develop the most advanced methods of their elimination. More intensive application of selected micro-organisms, capable of using variable valency chemicals as terminal acceptors, can help to treat wastewater from organic and mineral pollutants.
 Materials and methods. The co-authors have performed a review of literature and used analytical equipment to conduct laboratory researches according to standard and advanced methodologies.
 Results. The principal results include the restructuring of the treatment facilities operated by Autodetail Open Joint Stock Company. The restructuring consisted in the feeding process change in the currently used biological tower for the feeding to be performed with the help of the fiber carrier and immobilized association of oil oxidizing microorganisms. The association was obtained in the course of earlier laboratory researches. The most active nitrogen-gathering and oil oxidizing cultures, including Rhodococcus erythropoltis, Pseudomonas fluorescens, Arthrobacter tumescens, Pseudomonas rathonis, Azotobacter chroococcum, taken in equal parts, helped to develop a bio-product designated for the decomposition of oil and its components in the aquatic environment. This bio-product was immobilized in respect of the feeding to be performed with the help of the fiber carrier and loaded into the production company’s biological tower which is part of idle wastewater treatment facilities.
 Conclusions. In the course of the work performed at the first stage, special cultures were selected for the treatment of water from hydrocarbons of anthropogenic origin. These cultures had nitrogen-fixing properties needed to reduce secondary anthropogenic pollution of the water body. At the second stage, water treatment facilities of Autodetail Open Joint Stock Company were restructured and operation-related results were obtained. They enabled the researchers to make a statement that the biological transformation of pollutions was efficiently applicable to the suspended matter — 99.7 %; oil products — 98.3 %; COD — 89.2 %; nitrogen of ammonium salts — 77.9 %; mineral phosphorus — 53.3 %.
 Acknowledgements: The co-authors would like to express gratitude to all reviewers and the writing team for the publication of this article.

Испытание иммобилизованных микроорганизмов-нефтедеструкторов в полевых условиях месторождения Жанаталап Атырауской области

Hydrocarbon-oxidizing microorganisms are widespread in natural ecosystems, since the ability to oxidize hydrocarbons is associated with the presence of enzymes of the oxidase group, with microorganisms using oil and oil products as the sole source of carbon and energy in the microbiological decomposition of hydrocarbons. The decomposition of oil and oil products in the soil under natural conditions is a biogeochemical process in which the functional activity of a complex of soil microorganisms that ensure the complete mineralization of oil and oil products to carbon dioxide and water is of crucial importance. The search for effective indigenous hydrocarbon-oxidizing microorganisms, the creation on their basis of a full-fledged specialized consortium of microorganisms and their introduction into the initial, cleaned environment is one of the promising methods of purification with oil pollution in the oil-producing regions of Kazakhstan. Among the new biological methods for cleaning soil from oil pollution, the most promising are the use of a consortium based on immobilized microorganisms. A correctly selected carrier capable of sorption of petroleum hydrocarbons preserves and maintains attached cells in a viable state for a long time and protects them, especially at the initial stage of introduction, from adverse environmental conditions, which increases the efficiency of oil destruction. Hydrocarbon-oxidizing microorganisms have high emulsifying activity and sorption ability for expanded clay, optimal conditions for biomass accumulation are: temperature 28-30 °С, pH = 7 and 9. It is recommended to use a consortium of oil-degrading microorganisms based on the native strains of cultures Bacillus firmus S20, Bacillus subtilis PR28, Micrococcus roseus UD6-4, Micrococcus varians PR69 to clean the soils contaminated with oil and oil products in the Zhanatalap field in the Atyrau region. It should be noted that after 8 months at the Zhanatalap field in the Atyrau region, oil destruction amounted to 94.3% in the variant with the introduction of immobilized microorganisms on zeolite and expanded clay. The results of the research are the basis for further development of technology for the restoration of oil-contaminated soils in arid conditions of Kazakhstan.

Heat capacity and thermal diffusivity of heavy oil saturated rock materials at high temperatures

As well-known the rate of heat extraction depends on the thermal conductivity, $$Q = - \, \lambda \left( T \right){\text{grad }}T$$ , and the fluids flow characteristics, while amounts of heat recovery depends on heat capacity of reservoir rocks, $$Q = \left( {1 - \phi } \right)\rho C_{\text{P}} T$$ , where $$\phi$$ is the porosity. In the present work the laser-flash (LFA 457) and differential scanning calorimeter (DSC 204 F1) techniques were employed on a heavy oil saturated natural rock sample for accurate measurements of the thermal diffusivity and heat capacity over a temperature range from (294 to 1024) K and from (306 to 771) K, respectively. The density of the sample at room temperature was 2300 kg m−3 and the porosity was 17.1%. The sample for the present study comes from Russian Oil Field (Eastern Siberia, Russia). The expanded uncertainty of the thermal diffusivity and heat capacity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 3% and 1%, respectively. At low temperatures (below approximately 373 K), the sharp increases (up to η = 2.3) of the thermal diffusivity anisotropy was observed. Based on the measured thermal diffusivity and heat-capacity data, thermal conductivity of the same oil saturated rock sample was calculated using the thermodynamic relation $$\lambda = a\rho C_{\text{P}}$$ . The effect of temperature and various physical and chemical processes, such as thermal decomposition (chemical reactions) of pore heavy oil occurred in the sample during the heating in distinct temperature ranges were studied. The effect of pore heavy oil decomposition (under thermal stress) on the measured values of heat capacity and other thermophysical properties of rock sample at high temperatures (around 700 K) was experimentally observed. Also, we experimentally found weak temperature maximum of the heat-capacity of the sample under study in the low temperature range (around 380 K).

Kinetic study of the thermal decomposition of castor oil based polyurethane

Polyurethane is a class of polymer that presents as main feature the versatility in its physical and chemical properties. Knowing the kinetic parameters of the thermal degradation of these materials collaborates with the development of new applications. Therefore, this work had as objective to study of the kinetic parameters of the thermal decomposition of vegetable oil-based polyurethane (castor oil), through non - isothermal thermogravimetric method. The thermogravimetric curves of the samples showed two decomposition steps, and the kinetic parameters of each step were determined using the Flynn-Wall-Ozawa (FWO) method. The first stage of thermal decomposition presents characteristics of first-order reactions, the second stage of decomposition presented a behavior similar to that of the first stage until α equal to 0.4, in the conversion range between 0.4 and 0.9 a concave profile was observed, characteristic of complex processes, indicating parallel reactions and minimum lifetime of 1650 years old.

Silicon Nanowire-Graphite Composites As High Energy Anode Materials for Lithium Ion Batteries

Silicon is one of the most promising candidates to replace commercial graphite anodes in the next generation of lithium-ion batteries. Although numerous efforts have been devoted to improve the electrochemical performance of the Si based anodes, scalable synthesis of such materials and retaining good cycling stability in high loading electrode remain unaddressed. In pursuit of this goal, we propose a simple and scalable approach to synthesize a novel architecture containing silicon nanowires (SiNWs) grown on carbon powder (graphite, graphene, carbon black). SiNWs are grown from gold nanoparticle catalysts deposited on carbon and from the thermal decomposition of an organosilane oil, diphenylsilane, at 430°C [1]. The SiNWs show thin, homogeneous diameters and a high aspect ratio (the left figure shows a typical SEM image). Composites including up to 70wt% of Si on carbon black and 40wt% Si on graphite are obtained at the gram scale within 2 hours.SiNWs grown on graphite (Gt) anodes with 23 to 40 wt% of Si content demonstrated their relevance in next-generation high capacity anodes. This unique design can prevent the pulverization and crack by effectively accommodating the volume expansion during cycling. Consequently, Gt-SiNWs anodes exhibit a reversible capacity of 950 mAh g-1 after 180 cycles with 82 % capacity retention at C/5 rate. FIB-SEM cross sectional images of cycled anodes (detail shown on the right figure, 210 cycles) show that both Gt and SiNW are actively participating in (de)lithiation. As was shown in previous work on graphite-silicon nanoparticle composites, porosity increases in the graphite after cycling [2] correlates with the effective accommodation of volume change of SiNWs during cycling. More importantly, SiNWs are highly connected with graphite even after completing 210 cycles, while nanoporosity in the SiNWs aggregates is maintained.Gt-SiNW anodes were cast with an electrode density of 1.5 g cm-3, compatible with industrial application. Even at 2C rate, Gt-SiNW anodes retain 87% of capacity after 500 cycles, showing a higher long-term stability than Si nanoparticle-carbon composites [3], even at various mass loading ranging from 0.8 to 2.7 mg cm-2, providing up to 2.5mAh/cm2. A full cell consisting of Gt-SiNW anode and NMC cathode delivers a high capacity of 17 mAh with 53% capacity retention after 250 cycles. Ongoing prelithiation studies are expected to increase the capacity retention by at least 30% by avoiding initial capacity loss. This work provides insights into the rational design of SiNWs anodes with wide variety of carbon substrates for high energy density batteries.

Natural and Activated Allophane Catalytic Activity Based on the Microactivity Test in Astm Norm 3907/D3907M-2019

The optimal conditions of the catalytic activation of allophane were evaluated for possible use as a catalyst within a fluidized bed catalytic cracking unit (FCC). The physicochemical properties of natural allophane and activated allophane were studied by using an alkaline activating agent, followed by a hydrothermal treatment. For the characterization, analytical techniques were used: Fourier transform infrared spectroscopy, particle size, (BET) surface area, thermogravimetry (TGA), X-ray diffraction (XRD), chemisorption, X-ray fluorescence (XRF), atomic force microscopy (AFM), and chromatography. The catalytic evaluation was determined by the (MAT) micro activity test equipment constructed according to ASTM D-3907/D3907M-2019. In addition, the Navier–Stokes 3D equations (nonlinear partial derivatives) were studied, which allow studying molecular dynamics contributing substantively to chemical kinetics describing the process of decomposition of crude oil in thermal cracking, determining the maximum temperature at which it retains its properties through the action of heat.

Fluorescence-Based Determination of Olive Oil Quality Using an Endoscopic Smart Mobile Spectrofluorimeter

The application of self-contained field-portable, internet connected spectroscopic diagnostics in food analysis using a fibre endoscopic smart fluorimeter is reported. A UV-induced fluorescence is used to measure the quality of olive oils, distinguishing between extra virgin and others within a smartphone platform. When excited at $\lambda \sim ~370$ nm, the extra virgin olive oil fluoresces red at $\lambda \sim ~670$ nm. Notably, other oils do not fluoresce red but rather blue, consistent with degradation of the chlorophyll in the oil. Artificial refinement employed in some of the commercial products removes the red emission providing a simple method for distinguishing extra virgin olive oil from all other oils. A smartphone endoscopic fluorimeter is designed and constructed that measures the emission band $\Delta \lambda \sim $ (400– 700) nm with $\lambda \sim ~370$ nm excitation. The instrument is used to characterise the fluorescence of the oils. Photo-degradation over time for extra virgin olive oil under room lights is observed, demonstrating the origin for the decomposition of extra virgin olive oil in transparent bottles. Extra virgin olive oils are also susceptible to thermal degradation more than refined oils.

МҰНАЙ ҚАЛДЫҚТАРЫ МЕН РАДИОАКТИВТІК ЗАТТАРМЕН ЛАСТАНҒАН ТОПЫРАҚТЫ ТАЗАЛАУ ҮЛГІЛЕРІ

Oil production and transportation is a source of a large amount of waste. These wastes include oil sludge. The composition of these oil sludge, in addition to oil components, includes elements of natural radionuclides. The level of soil contamination with oil is caused by adverse effects on the plant, mainly changes in its physical and chemical properties (hydrophobic increase, filling of soil capillaries with oil) and direct toxic effects of toxic components contained in oil. The positive effect of sowing plants on oil-polluted soils is explained by the fact that the plant uses petroleum hydrocarbons as an additional food and improves the gas-air regime of polluted soils, while enriching it with various active additives, which ultimately stimulates the growth of the number of microorganisms and, accordingly, accelerates the decomposition of oil and petroleum products. The influence of waste containing petroleum components and elements of natural radionuclides on soil conditions and reduction of radioactivity by local sorbents was studied

Valorisation of End of Life Tyres (ELTs) in a Newly Developed Pyrolysis Fixed-Bed Batch Process

This article shows a preliminary study of an end of life tyres (ELTs) use as a feedstock in a newly developed and patented reactor system that utilises a three zone heating element set-up along its fixed bed. The pyrolysis reaction was conducted between 500 to 700 °C and has yielded a maximum pyrolysis oil at 500 °C which was attributed to the promotion of secondary cracking of the oil into permanent (non-condensable) gaseous products. The oil yield and properties including estimated mass balance, sulphur content and higher heating value (HHV) shows that the pyro-oil is within fuel standards of the market making it a green and renewable resource off of waste. In addition, The hydrocarbon (HC) range of the products obtained from the oil shows that it is within the diesel range of typical fuels. The analysis of the gaseous products from the pyrolysis showed that an increase in the average reactor bed temperature promotes the decomposition of primary HC and pyrolysis oil into secondary products. This results in the detection of tetradecanoic acid, limonene and eicosane, among other major chemical groups at temperatures above 550 °C which is the end-set temperature of feedstock examined. It can be concluded that by using such a reactor set-up and upgrading the fuels extracted from its downstream stigmatic features of fixed bed reactors might be overcome with a lucrative economical value and rate of return in a circular economy perspective.

Numerical simulation on biomass-pyrolysis and thermal cracking of condensable volatile component

We studied the physical and chemical properties of the condensable volatiles of biomass pyrolysis products. We redefine the liquid product and divide the condensable volatiles into two categories, biomass oil and tar, the latter of which comes from the secondary pyrolysis or cracking reaction of the former. We further establish a kinetic model of biomass pyrolysis and secondary cracking. The chemical reaction kinetics equation and heat transfer equation are coupled to simulate the biomass pyrolysis process. For biomass solid particles, the model not only considers the initial reaction of biomass and secondary cleavage reaction of condensable gas, but also introduces a reaction mode in which biomass oil is converted into tar. When the pyrolysis temperature is below 500 °C, the pyrolysis products are essentially biomass oil. However, when the pyrolysis temperature exceeds 500 °C, the biomass oil gradually converts into tar. The model also considers characteristics of the reaction medium (porosity, intrinsic permeability, thermal conductivity) and the unsteady gas phase process based on Darcy's law of velocity and pressure, heat convection, diffusion, and radiation transfer. We analyze the relationships among the internal temperature of the particles, particle size and position, mass fraction of the reactants and products, the gas mixture, the production share of tar and biomass oil, and the relationship between gas pressure and time. The results show that the effects of the secondary cracking reaction and internal convective flow in the biomass pyrolysis process are coupled because the flow field in the porous medium determines the volatile residence time and thus species that affect the secondary cracking reaction. The rate of volatile formation in the initial and secondary cracking reactions affects the pressure gradient and gas diffusion. Additionally, the endothermic effect influences the temperature field of the pyrolysis reaction but has no apparent effect on small particles whose chemical reaction is the control mechanism. For large particles, heat transfer inside the particles is the diffusion control mechanism and the chemical reaction on the particle surface is the speed control mechanism. Two peaks are observed in the pyrolysis gas mass proportion curve, which result from the consumption of biomass oil and tar as they flow toward hot surfaces. The first peak is the decomposition of biomass oil into non-condensable volatile matter and tar, and the second peak is the further cracking of tar into gas and coke at high temperature.

The influence of oil pollution and carriers of biological product on the agrophysical indicators of sod-podzolic soils

The article presents the results of the influence of various aerating agents, carriers of new generation oil-oxidizing biological product on the agrophysical parameters of sod-podzolic soil highly contaminated with oil (up to 10%), and on the rate of oil decomposition in it. The studies were carried out in a microfield experiment in the conditions of the Udmurt Republic. It was established that during the growing season of 2019 all studied carriers of the biological product had positive effect on these indicators, however, the parameters of the changes were determined by their types. Thus, the application of sawdust, barley straw and flax shive into the soil provided an increase in the structural coefficient by 0.83-0.99 units or 35-43 %. All studied carriers of the biological product statistically significantly reduced the density of the contaminated soil, the greatest effect on this indicator was exerted by flax shive (by 0.42 g/cm3 or 32 %) and sawdust (by 0.34 g/cm3 or by 26 %). The application of vermiculite increased the productive moisture content in the contaminated soil most significantly - by 115 m3 /ha or by 50.7 %. The improvement of agrophysical properties of oil-contaminated soil by carriers of the biological product increased drastically the effectiveness of the preparation for oil decomposition. The greatest effect on this indicator (by 9.9-10.9 mg/kg or 40.2- 44.3 %) was exerted by the biological product in combination with flax shive, lignin and straw. The application of organomineral fertilizers into the contaminated soil also improved the agrophysical properties of oil-contaminated soils significantly and reduced the residual oil content in it by 13.0 mg/kg or 52.8 %.

Bioremediation of oil-contaminated soil by combination of soil conditioner and microorganism

Oil hydrocarbons are widespread pollutants in soil which pose serious threats to ecological environment. Thus, this study carried out the bioremediation of oil-contaminated soil by using the efficient petroleum-degrading bacteria and soil conditioner, to investigate the changes of physicochemical properties of contaminated soil during bioremediation, reveal the relationship among the exogenous degradation strains and indigenous microbe, and finally illuminate the effects of soil conditioner and microbe on the bioremediation of oil-contaminated soil. A PAH-degrading strain named Stenotrophomonas maltophilia was used in this study, which was isolated from an e-waste dismantling area. The soil conditioner in this present study was developed previously by using agricultural wastes, which was in a powdered form and rich in N, P, and K. The simulated experiments were conducted under the control environmental conditions of greenhouse, to study the effects of inoculation and soil conditioner on bioremediation of oil-contaminated soil. Then, the physicochemical properties of soil and the degradation rates of oil were measured at different set times to evaluate the bioremediation effect. Adding 1% soil conditioner could significantly improve the soil conditions and offer microorganism enough N, P, and K, which would promote microbial growth and played a key role on bioremediation of oil-contaminated soil. Although in polluted soil, the microorganism could maintain metabolic activity and use the petroleum as carbon source. The soil indigenous microbe was more easily to adapt to the contaminated surrounding. However, when both of them co-existed in soil, they would restrain each other, and go against the oil decomposition. Thus, making two types of microorganisms work to achieve synergy was the key to gain much better remediation effect. Because the indigenous microbe was good at decomposing low molecular compounds and saturated hydrocarbons, while the oil-degrading strains can effectively decompose high molecular weight aromatics. The soil nutrient and microorganism, including the exogenous oil-degrading strains and the soil indigenous microbe, had an important effect on degradation of petroleum. The addition of soil conditioner, presence of indigenous microbe, and inoculation of oil-degrading strains all were conducive to bioremediation of oil-contaminated site, but the key was to control the proportion and relationship of the three.

Genomic Characterization and Expressional Profiles of Autophagy-Related Genes (ATGs) in Oilseed Crop Castor Bean (Ricinus communis L.).

Cellular autophagy is a widely-occurring conserved process for turning over damaged organelles or recycling cytoplasmic contents in cells. Although autophagy-related genes (ATGs) have been broadly identified from many plants, little is known about the potential function of autophagy in mediating plant growth and development, particularly in recycling cytoplasmic contents during seed development and germination. Castor bean (Ricinus communis) is one of the most important inedible oilseed crops. Its mature seed has a persistent and large endosperm with a hard and lignified seed coat, and is considered a model system for studying seed biology. Here, a total of 34 RcATG genes were identified in the castor bean genome and their sequence structures were characterized. The expressional profiles of these RcATGs were examined using RNA-seq and real-time PCR in a variety of tissues. In particular, we found that most RcATGs were significantly up-regulated in the later stage of seed coat development, tightly associated with the lignification of cell wall tissues. During seed germination, the expression patterns of most RcATGs were associated with the decomposition of storage oils. Furthermore, we observed by electron microscopy that the lipid droplets were directly swallowed by the vacuoles, suggesting that autophagy directly participates in mediating the decomposition of lipid droplets via the microlipophagy pathway in germinating castor bean seeds. This study provides novel insights into understanding the potential function of autophagy in mediating seed development and germination.

Efficient removal of oil pollutant via simultaneous adsorption and photocatalysis using La–N–TiO2–cellulose/SiO2 difunctional aerogel composite

Nano-TiO2 photocatalysts doped with La–N(La–N–TiO2) were prepared by solgel method. The La–N–TiO2 was loaded on the cellulose/SiO2 composite aerogel (La–N–TiO2–CSA). La–N–TiO2–CSA had both oil absorption and oil degradation functions under the sun. The static state water contact angle is up to 148° close to superhydrophobic surface. An apparent decomposition rate of oil is 92%, which is much higher than 26% of pure TiO2. Under the visible light irradiation, the photocurrent density has increased by 50%. Characterization results show that LaONO3 was uniformly distributed in TiO2 crystal. Compared with pure TiO2, the UV–Vis DRS data showed the absorption band of La–N–TiO2 had extended to 441 nm. The La increased the valence band position and N lowered the conduction band position, which reduced the band gap of TiO2 from 3.59 to 2.81 eV. The formation of LaONO3 reduced carrier transfer resistance, and the migration rate and electron–hole separation efficiency were improved. The possible oil decomposition pathways were proposed.

Effect of Surface Roughness on Tribochemical Decomposition of Synthetic Oils under High-Vacuum Conditions

Effect of Surface Roughness on Tribochemical Decomposition of Synthetic Oils under High-Vacuum Conditions

Physicochemical characterizations, antimicrobial activity and non-isothermal decomposition kinetics of Cinnamomum cassia essential oils

ABSTRACTThe extraction of essential oils from Cinnamomum cassia bark and leaf was carried out by hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD). Chemical compositions of volatile compounds were determined by GC/MS, 1H-NMR and infrared spectroscopy analysis. The dominant constituents found in the essential oils were aromatic compounds (> 90%) including (E)-cinnamaldehyde (CAL) and (E)-cinnamyl acetate (CAC) as the major components. The thermogravimetry (TG) method was used to study thermal stability and volatilization of the oils at room temperature. The bark essential oils exhibited inhibitory effects against a bacterial strain, S. aureus and a yeast strain, S. cerevisiae at MIC value 200 µg/mL. The decomposition kinetic of the essential oils was studied via the isoconversional kinetic models using the TG data. Two the isoconversional models, Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) were used to determine activation energies (Ea) for decomposition of the essential oils.

Temperature effect on thermal-diffusivity and heat-capacity and derived values of thermal-conductivity of reservoir rock materials

A laser flash method (micro-flash apparatus LFA 457) and differential scanning calorimeter (DSC 204 F1) were employed to study of the temperature effect on the thermophysical properties (thermal diffusivity $$a$$, heat capacity $$C_{\text{P}}$$ and thermal conductivity $$\lambda$$) of the natural reservoir rock sample. A relationship between the thermophysical properties behavior and the physical–chemical processes (thermal decomposition of pore heavy oil and volatilization of pore fluids) occurring in the rock’s pore fluids during heating in distinct temperature ranges was established. The measurements of the thermal-diffusivity have been made over the temperature range from 295 to 774 K. The isobaric heat capacities (CP) of the same sample were measured in the temperature range from 308 to 768 K. Uncertainties of the measurements are 3% and 1% for $$a$$ and $$C_{\text{P}}$$, respectively. The significant effect of thermal decomposition on the measured values of heat-capacity of reservoir rock sample at high temperatures (above 680 K) was experimentally found. We experimentally observed temperature anomaly of the heat capacity of rock sample in distinct temperature ranges, around 380 K (low-temperature range) and 680 K (high-temperature range).We attribute these anomalies to the dehydration (evolution of the volatile matter, VM, devolatilization) and aromatization of the carbon (thermal decomposition), which are known to occur under heat treatment. This leads to unusual increasing the heat capacity at high temperatures. Measured values of thermal diffusivity ($$a$$) and heat capacity ($$C_{\text{P}}$$) together with density data ($$\rho = { 2210}\;{\text{kg}}\;{\text{m}}^{ - 3}$$) were used to calculate the derived key properties, thermal conductivities ($$\lambda$$) of the rock sample, using very well-known relation, $$\lambda = a\rho C_{\text{P}}$$.