Showing papers on "Hydrocarbon published in 2015"
TL;DR: Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants, however, these compounds are slowly degraded by a large variety of microorganisms.
Abstract: Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants. However, these compounds are slowly degraded by a large variety of microorganisms. Bacteria are able to degrade aliphatic saturated and unsaturated hydrocarbons via both aerobic and anaerobic pathways. Branched hydrocarbons and cyclic hydrocarbons are also degraded by bacteria. The aerobic bacteria use different types of oxygenases, including monooxygenase, cytochrome-dependent oxygenase and dioxygenase, to insert one or two atoms of oxygen into their targets. Anaerobic bacteria, on the other hand, employ a variety of simple organic and inorganic molecules, including sulphate, nitrate, carbonate and metals, for hydrocarbon oxidation.
281 citations
TL;DR: In this article, a reduced toluene reference fuel (TRF, n -heptane, iso-octane, benzene (C 6 H 6 -A 1 ), polycyclic-aromatic hydrocarbon (PAH) chemistry mechanism was proposed for combustion, PAH and soot formation predictions.
159 citations
01 Jan 2015
TL;DR: In this article, the authors investigated the ignition propensity of two alkane-rich FACE (Fuels for Advanced Combustion Engines) gasoline test fuels and their corresponding PRF blend in fundamental combustion experiments.
Abstract: Petroleum derived gasoline is the most used transportation fuel for light-duty vehicles. In order to better understand gasoline combustion, this study investigated the ignition propensity of two alkane-rich FACE (Fuels for Advanced Combustion Engines) gasoline test fuels and their corresponding PRF (primary reference fuel) blend in fundamental combustion experiments. Shock tube ignition delay times were measured in two separate facilities at pressures of 10, 20, and 40 bar, temperatures from 715 to 1500 K, and two equivalence ratios. Rapid compression machine ignition delay times were measured for fuel/air mixtures at pressures of 20 and 40 bar, temperatures from 632 to 745 K, and two equivalence ratios. Detailed hydrocarbon analysis was also performed on the FACE gasoline fuels, and the results were used to formulate multi-component gasoline surrogate mixtures. Detailed chemical kinetic modeling results are presented herein to provide insights into the relevance of utilizing PRF and multi-component surrogate mixtures to reproduce the ignition behavior of the alkane-rich FACE gasoline fuels. The two FACE gasoline fuels and their corresponding PRF mixture displayed similar ignition behavior at intermediate and high temperatures, but differences were observed at low temperatures. These trends were mimicked by corresponding surrogate mixture models, except for the amount of heat release in the first stage of a two-stage ignition events, when observed.
151 citations
TL;DR: In this paper, the authors used the IRAM 30 m telescope to carry out a millimetre line survey towards the Orion Bar edge, complemented with ~2′ × 2′ maps of the C2 H and c -C3 H2 emission.
Abstract: Context. Carbon chemistry plays a pivotal role in the interstellar medium (ISM) but even the synthesis of the simplest hydrocarbons and how they relate to polycyclic aromatic hydrocarbons (PAHs) and grains is not well understood.Aims. We study the spatial distribution and chemistry of small hydrocarbons in the Orion Bar photodissociation region (PDR), a prototypical environment in which to investigate molecular gas irradiated by strong UV fields.Methods. We used the IRAM 30 m telescope to carry out a millimetre line survey towards the Orion Bar edge, complemented with ~2′ × 2′ maps of the C2 H and c -C3 H2 emission. We analyse the excitation of the detected hydrocarbons and constrain the physical conditions of the emitting regions with non-LTE radiative transfer models. We compare the inferred column densities with updated gas-phase photochemical models including 13 CCH and C13 CH isotopomer fractionation.Results. Approximately 40% of the lines in the survey arise from hydrocarbons (C2 H, C4 H, c -C3 H2 , c -C3 H, C13 CH, 13 CCH, l -C3 H, and l -H2 C3 in decreasing order of abundance). We detect new lines from l -C3 H+ and improve its rotational spectroscopic constants. Anions or deuterated hydrocarbons are not detected, but we provide accurate upper limit abundances: [C2 D]/[C2 H] H− ]/[C2 H] H− ]/[C4 H] Our models can reasonably match the observed column densities of most hydrocarbons (within factors of H and c -C3 H2 emission is similar but does not follow the PAH emission, we conclude that, in high UV-flux PDRs, photodestruction of PAHs is not a necessary requirement to explain the observed abundances of the smallest hydrocarbons. Instead, gas-phase endothermic reactions (or with barriers) between C+ , radicals, and H2 enhance the formation of simple hydrocarbons. Observations and models suggest that the [C2 H]/[c -C3 H2 ] ratio (~32 at the PDR edge) decreases with the UV field attenuation. The observed low cyclic-to-linear C3 H column density ratio (≤3) is consistent with a high electron abundance (x e ) PDR environment. In fact, the poorly constrained x e gradient influences much of the hydrocarbon chemistry in the more UV-shielded gas. The inferred hot rotational temperatures for C4 H and l -C3 H+ also suggest that radiative IR pumping affects their excitation. We propose that reactions of C2 H isotopologues with 13 C+ and H atoms can explain the observed [C13 CH]/[13 CCH] = 1.4 ± 0.1 fractionation level.
132 citations
TL;DR: In this article, the authors explored the decomposition of methane by iron catalyst to produce hydrogen and carbon using co-precipitation technique and showed the formation of multwalled nanotubes from alumina supported iron catalysts.
128 citations
TL;DR: In this paper, the effects of SiO2, NiO, and Fe3O4 nanoparticles on oil recovery and how they adsorb asphaltene and prevent its precipitation were investigated.
Abstract: Preventing asphaltene-related damage in hydrocarbon reservoirs is an important concern. Many investigations have been performed on asphaltene and its effects and how to reduce these effects during oil production. In the present work, some experiments were conducted to investigate the effects of SiO2, NiO, and Fe3O4 nanoparticles on oil recovery and to determine how they adsorb asphaltene and prevent its precipitation. Moreover, instead of crude oil, a synthetic solution with a given component concentration was used. The results of this study show that, in solutions without nanoparticles, an increase in the amount of n-heptane causes more asphaltene aggregation to take place; however, in the presence of nanoparticles, increasing the n-heptane content results in an increase in the asphaltene adsorption on the surface of nanoparticles. Furthermore, it is shown that the amount of oil recovery in the presence of different nanoparticles corresponds to the ordering SiO2 > NiO > Fe3O4.
124 citations
TL;DR: The operando spectroscopy results suggest that the nature of the active species also influences the olefin selectivity, and monoenylic and highly methylated benzene carbocations are more selective to the formation of propylene.
Abstract: The selectivity toward lower olefins during the methanol-to-olefins conversion over H-SAPO-34 at reaction temperatures between 573 and 773 K has been studied with a combination of operando UV–vis diffuse reflectance spectroscopy and online gas chromatography. It was found that the selectivity toward propylene increases in the temperature range of 573–623 K, while it decreases in the temperature range of 623–773 K. The high degree of incorporation of olefins, mainly propylene, into the hydrocarbon pool affects the product selectivity at lower reaction temperatures. The nature and dynamics of the active and deactivating hydrocarbon species with increasing reaction temperature were revealed by a non-negative matrix factorization of the time-resolved operando UV–vis diffuse reflectance spectra. The active hydrocarbon pool species consist of mainly highly methylated benzene carbocations at temperatures between 573 and 598 K, of both highly methylated benzene carbocations and methylated naphthalene carbocations...
105 citations
TL;DR: In this article, real-world mixed plastics and a simulated mixture of plastics were processed in a two-stage pyrolysis-catalysis fixed bed reactor in the presence of a zeolite HZSM-5 catalyst.
Abstract: Real-world postconsumer mixed plastics and a simulated mixture of plastics were processed in a two-stage pyrolysis–catalysis fixed bed reactor in the presence of a zeolite HZSM-5 catalyst. In addition, single plastic polyethylene, polypropylene, polystyrene, and polyethylene terephthalate were also processed in the two-stage reactor. The product yield, composition, and hydrocarbon distribution of the product oil was obtained in relation to plastic type. Noncatalytic pyrolysis of the plastics produced a high yield of an oil/wax product in the 81–97 wt % range. Addition of the catalyst reduced the yield of oil to between 44 and 51 wt %, with an increase in gas yield from cracking of the oil volatiles. However, the condensed oils produced from pyrolysis–catalysis were enriched with lower molecular weight (C5–C15) hydrocarbons and were markedly more aromatic in composition with a high proportion of single-ring aromatic hydrocarbons. Comparison of the results from pyrolysis and pyrolysis–catalysis of the simul...
104 citations
TL;DR: In this article, the effects of zeolite acid properties to the aromatization of glycerol were investigated over HZSM-5 with various SiO2/Al2O3 ratios, i.e., 23, 30, 50, 80, and 280.
98 citations
TL;DR: In this paper, the effect of non-catalyst and catalyst on the physicochemical properties and yield of products was discussed, and the results showed that the introduction of Zn did not change the zeolite crystalline structure and ZnO might deposit on the external surface and/or inside the pores of the support ZSM-5.
97 citations
TL;DR: Investigations suggest that in the hydrocarbon reactant, the vinyl-type group must be in conjugation with a -C≡CH or -HC=CH2 group to form a resonantly stabilized free radical intermediate, which eventually isomerizes to a cyclic intermediate followed by hydrogen loss and aromatization (PAH formation).
Abstract: Bimolecular reactions of phenyl-type radicals with the C4 and C5 hydrocarbons vinylacetylene and (methyl-substituted) 1,3-butadiene have been found to synthesize polycyclic aromatic hydrocarbons (PAHs) with naphthalene and 1,4-dihydronaphthalene cores in exoergic and entrance barrierless reactions under single-collision conditions. The reaction mechanism involves the initial formation of a van der Waals complex and addition of a phenyl-type radical to the C1 position of a vinyl-type group through a submerged barrier. Investigations suggest that in the hydrocarbon reactant, the vinyl-type group must be in conjugation with a –C≡CH or –HC=CH2 group to form a resonantly stabilized free radical intermediate, which eventually isomerizes to a cyclic intermediate followed by hydrogen loss and aromatization (PAH formation). The vinylacetylene-mediated formation of PAHs might be expanded to more complex PAHs, such as anthracene and phenanthrene, in cold molecular clouds via barrierless reactions involving phenyl-ty...
TL;DR: In this article, the effect of molybdenum on the activity of Ni-based catalysts in the hydrodeoxygenation of fatty acid esters was studied, and it was found that an increase in the Mo content (from 0.0% to 6.9%) in the Ni-Cu-Mo/Al 2 O 3 catalysts leads to an increased yield of normal alkanes.
Abstract: The effect of molybdenum on activity of Ni-based catalysts in the hydrodeoxygenation of fatty acid esters was studied. Catalysts Ni-Cu/Al 2 O 3 , Ni-Mo/Al 2 O 3 , Cu-Mo/Al 2 O 3 , Mo/Al 2 O 3 , and Ni-Cu-Mo/Al 2 O 3 with different ratios Ni/Mo were prepared and tested in the hydrodeoxygenation of methyl palmitate and ethyl caprate at 300 °С, 1 MPa. It was found that an increase in the Mo content (from 0.0% to 6.9%) in the Ni-Cu-Mo/Al 2 O 3 catalysts leads to an increase in the yield of normal alkanes. The catalysts were characterized by X-ray photoelectron spectroscopy (XPS), temperature programmed reduction and X-ray diffraction techniques. The XPS data showed that the increase in the conversion of fatty acid esters is related to changes in the ratio between different oxidation states of molybdenum (Mo 0 , Mo 4+ , and Mo 6+ ) on the surface of the Ni-Cu-Mo/Al 2 O 3 catalysts.
TL;DR: A dynamic multi-media model that includes temperature-dependency for partitioning and degradation was developed and predicted the behaviour of petroleum hydrocarbons during biopiling at low temperature, suggesting that relatively simple remediation techniques can be effective even in Antarctica.
TL;DR: In this paper, high-quality ZIF-8 membranes with a separation factor of ~90 for propylene/propane are successfully prepared via optimizing the activation processes, and single-component permeation data for hydrocarbons (C1-C4) through the improved zif-8 membrane are measured and analyzed by the Maxwell-Stefan (MS) model to get the transport diffusivities of these hydrocarains.
TL;DR: Strain gradients induced in the nanoconfined carbon shell result in the formation of a large number of active sites featuring a considerable catalytic activity for the combustion of a variety of hydrocarbons, and for methane combustion, the catalyst displays a unique activity being comparable or even superior to the palladium ones.
Abstract: Combustion catalysts have been extensively explored to reduce the emission of hydrocarbons that are capable of triggering photochemical smog and greenhouse effect. Palladium as the most active material is widely applied in exhaust catalytic converter and combustion units, but its high capital cost stimulates the tremendous research on non-noble metal candidates. Here we fabricate highly defective cobalt oxide nanocrystals via a controllable oxidation of carbon-encapsulated cobalt nanoparticles. Strain gradients induced in the nanoconfined carbon shell result in the formation of a large number of active sites featuring a considerable catalytic activity for the combustion of a variety of hydrocarbons (methane, propane and substituted benzenes). For methane combustion, the catalyst displays a unique activity being comparable or even superior to the palladium ones.
TL;DR: In this article, the authors review recent developments and technological advances in the field of electrochemical reduction of carbon dioxide to fuels, energy carriers and precursors and other interesting building blocks for industrial applications.
Abstract: Here we review recent developments and technological advances in the field of electrochemical reduction of carbon dioxide to fuels, energy carriers and precursors and other interesting building blocks for industrial applications Synthetic hydrocarbon fuels derived from CO2/H2O are proposed as alternatives to hydrogen as an energy carrier that enables a carbon-neutral energy cycle, given their inherent advantages of high H/C ratio and convenience of storage and transportation The electrochemical reduction of CO2 represents a feasible route for the direct generation of hydrocarbon fuels or their precursors (ie, synthesis gas) using CO2/H2O Such hydrocarbons fit well within the existing energy infrastructure because of their similarity to existing fossil fuels Recently significant efforts are being devoted to the development of prototype systems, such as low- or high- temperature electrolyzers that operate as part of environmentally sustainable energy networks
TL;DR: In this paper, the potential of HPAI without ignition for deep, high pressure, heavy oil reservoirs (Tahe oilfield, Tarim Basin, China) was evaluated.
Abstract: High pressure air injection (HPAI) without ignition has attracted extensive attention in the air injection based improved oil recovery (IOR) process for light oil reservoirs but was rarely proposed as an IOR process for heavy oil reservoirs. This study aims at evaluating the potential of HPAI without ignition for deep, high pressure, heavy oil reservoirs (Tahe oilfield, Tarim Basin, China). Many low-temperature oxidation (LTO) experiments were carried out to study the oxidation behavior of heavy oil under the reservoir conditions (120 °C, about 30–40 MPa) using an isothermal oxidation reactor. The produced gases were analyzed using gas chromatography for their content of O2, CO2, CO, and hydrocarbon gas (C1–C6) content. The apparent hydrogen/carbon (H/C) and molar ratio of the carbon oxides (m-ratio) were also calculated from effluent gases to analyze oxidation behavior. The effects of quartz, reservoir core (characterized by X-ray diffraction), formation water, and catalyst on LTO were analyzed. Thermogr...
TL;DR: The capabilities of the isolated bacterial strains to degrade alkanes and PAHs should be of great practical significance in bioremediation of oil-contaminated environments.
Abstract: Crude oil is a common environmental pollutant composed of a large number of both aromatic and aliphatic hydrocarbons. Biodegradation is carried out by microbial communities that are important in determining the fate of pollutants in the environment. The intrinsic biodegradability of the hydrocarbons and the distribution in the environment of competent degrading microorganisms are crucial information for the implementation of bioremediation processes. In the present study, the biodegradation capacities of various bacteria toward aliphatic and aromatic hydrocarbons were determined. The purpose of the study was to isolate and characterize hydrocarbon-degrading bacteria from contaminated soil of a refinery in Arzew, Algeria. A collection of 150 bacterial strains was obtained; the bacterial isolates were identified by 16S rRNA gene sequencing and their ability to degrade hydrocarbon compounds characterized. The isolated strains were mainly affiliated to the Gamma-Proteobacteria class. Among them, Pseudomonas spp. had the ability to metabolize high molecular weight hydrocarbon compounds such as pristane (C19) at 35.11 % by strain LGM22 and benzo[a] pyrene (C20) at 33.93 % by strain LGM11. Some strains were able to grow on all the hydrocarbons tested including octadecane, squalene, phenanthrene, and pyrene. Some strains were specialized degrading only few substrates. In contrast, the strain LGM2 designated as Pseudomonas sp. was found able to degrade both linear and branched alkanes as well as low and high poly-aromatic hydrocarbons (PAHs). The alkB gene involved in alkane degradation was detected in LGM2 and other Pseudomonas-related isolates. The capabilities of the isolated bacterial strains to degrade alkanes and PAHs should be of great practical significance in bioremediation of oil-contaminated environments.
TL;DR: In this paper, a new pyrolytic pathway for biomass conversion to hydrocarbon fuel precursors was proposed, which involved the conversion of multifunctional oxygenates generated from biomass pyrolyses over a metal oxide catalyst into ketonic-rich monofunctional molecules suitable for making gasoline, diesel, and jet fuel.
01 Jan 2015
TL;DR: In this paper, the laminar flame speeds of C 3 oxygenated fuels ( n -propanol, propanal and acetone) and hydrocarbon (propane) were measured in a combustion bomb to compare combustion characteristics of C3 alcohol, aldehyde, ketone, and alkane.
Abstract: The laminar flame speeds of C 3 oxygenated fuels ( n -propanol, propanal and acetone) and hydrocarbon (propane) were measured in a combustion bomb to compare combustion characteristics of C 3 alcohol, aldehyde, ketone, and alkane Propanal shows the highest flame speeds while acetone gives the lowest one The experimental observations are further interpreted with chemical kinetic models The effects of distinctive molecular structures on the fuel consumption pathways are clarified Propanal generates a large H atom pool that enhances the oxidation, leading to the highest flame speeds However, acetone forms methyl radical (CH 3 ) and has lower flame speeds as a consequence The calculated maximum concentrations of H, OH, and CH 3 confirm this analysis It is found that propanal yields the highest H and OH concentrations while acetone produces the lowest H and OH concentrations among all tested fuels Moreover, acetone presents higher CH 3 concentration, especially for fuel rich condition n -Propanol and propane show comparable flame speeds and similar radical concentrations, especially H and OH The different kinetics among hydrocarbon species with the same carbon numbers can provide a horizontal view in the hierarchical hydrocarbon chemistry
TL;DR: In this article, the authors describe the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London), which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20-30 % of the total hydrocarbon mixing ratio but comprise more than 50% of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols.
Abstract: . Hydrocarbons are key precursors to two priority air pollutants, ozone and particulate matter. Those with two to seven carbons have historically been straightforward to observe and have been successfully reduced in many developed cities through air quality policy interventions. Longer chain hydrocarbons released from diesel vehicles are not considered explicitly as part of air quality strategies and there are few direct measurements of their gaseous abundance in the atmosphere. This study describes the chemically comprehensive and continuous measurements of organic compounds in a developed megacity (London), which demonstrate that on a seasonal median basis, diesel-related hydrocarbons represent only 20–30 % of the total hydrocarbon mixing ratio but comprise more than 50 % of the atmospheric hydrocarbon mass and are a dominant local source of secondary organic aerosols. This study shows for the first time that 60 % of the winter primary hydrocarbon hydroxyl radical reactivity is from diesel-related hydrocarbons and using the maximum incremental reactivity scale, we predict that they contribute up to 50 % of the ozone production potential in London. Comparing real-world urban composition with regulatory emissions inventories in the UK and US highlights a previously unaccounted for, but very significant, under-reporting of diesel-related hydrocarbons; an underestimation of a factor ~4 for C9 species rising to a factor of over 70 for C12 during winter. These observations show that hydrocarbons from diesel vehicles can dominate gas phase reactive carbon in cities with high diesel fleet fractions. Future control of urban particulate matter and ozone in such locations requires a shift in policy focus onto gas phase hydrocarbons released from diesels as this vehicle type continues to displace gasoline world-wide.
TL;DR: In this paper, the nickel phosphides supported on the commercial HZSM-22 catalysts were used to convert palmitic acid to diesel-like hydrocarbons under ambient pressure in the absence of any solvents.
Abstract: We have synthesized the nickel phosphides supported on the commercial HZSM-22 catalysts, which were used to convert palmitic acid to diesel-like hydrocarbons under ambient pressure in the absence of any solvents. The deoxygenation reactions of palmitic acid were studied in a fixed-bed reactor over HZSM-22, Ni x P/HZSM-22, Ni 2 P/HZSM-22, the unsupported Ni x P and the unsupported Ni 12 P 5 catalysts. The conversion of palmitic acid and the hydrocarbon yield were found to be 99.6% and 42.9%, respectively, for the best catalyst, 40 Ni x P/HZSM-22. The heat value of the resulting hydrocarbons was 46.4 MJ kg −1 . Ketones and aldehydes were identified as reaction intermediates, which were subsequently converted into hydrocarbons. In addition, short-chain hydrocarbons and aromatic hydrocarbons were generated, suggesting the presence of cracking and isomerization reactions. Our mechanistic exploration and the NH 3 adsorption–desorption DRIFT spectra suggest that the decarbonylation and decarboxylation are facilitated by Ni x P, whereas Bronsted acid sites on HZSM-22 play a crucial role in the isomerization reactions and Lewis acids sites on catalysts are responsible for the cracking reactions. The present study demonstrates that the catalysts such as Ni x P supported on commercial HZSM-22 can serve as a practical modus with excellent catalytic activity to produce diesel-like hydrocarbons from biomass-based oil.
TL;DR: In this paper, product ion yields for a suite of hydrocarbons associated with motor vehicle exhaust including alkenes, alkanes, cycloalkanes, and aromatic compounds are reported for a PTR-MS instrument operated at an E/N ratio of 80 and 120 Td.
TL;DR: In this paper, a composite catalysts comprised of Cu-Zn-Al oxide catalyst and HB zeolite was examined for the synthesis of C 2+ hydrocarbons by the combination of methanol synthesis over Cu−Zn−Al oxide and concurrent conversion of methenol over HB Zeolite.
Abstract: Synthesis of C 2+ hydrocarbons such as LPG (liquefied petroleum gas) from CO 2 is expected to reduce CO 2 emission by the consumption of fossil fuels. In this study, CO 2 hydrogenation over composite catalysts comprised of Cu–Zn–Al oxide catalyst and HB zeolite was examined for the synthesis of C 2+ hydrocarbons by the combination of methanol synthesis over Cu–Zn–Al oxide and concurrent conversion of methanol over HB zeolite. When a non-modified zeolite was used for the composite catalyst, the yield of C 2+ hydrocarbons was poor ( 2+ hydrocarbons were seriously deactivated. The employment of zeolites modified with 1,4-bis(hydroxydimethylsilyl) benzene remarkably improved the catalytic activity of the corresponding composite catalysts to produce C 2+ hydrocarbons in yields of more than 7C-mol%. The best yield of C 2+ hydrocarbons became approximately 12.6C-mol% under a pressure of 0.98 MPa. The disilane modification produced hydrophobic zeolites showing water contact angles more than 130°. The disilane compound was converted to some condensed aromatics during CO 2 hydrogenation at 300 °C, and the hydrophobicity was maintained even after the reaction. The enhanced catalytic activity is caused by suppressing the deactivation of the strong acid sites of HB zeolite with the hydrophobic surface. This improved composite catalyst will promote the production of C 2+ hydrocarbons from CO 2 even under low pressure conditions.
TL;DR: The results showed that the reaction temperature affected the hydrocarbon fuel yield but had a minor influence on its properties, including dynamic viscosity, pH, moisture content, density, oxygen content and heating value.
TL;DR: A suite of onshore Gulf coast oils and condensates generated from and accumulating in Smackover carbonates was assembled to include samples that experienced varying levels of TSR alteration and in reservoir thermal cracking as mentioned in this paper.
TL;DR: In this paper, the stable hydrogen isotope ratios of 313 natural gas samples from six of China’s sedimentary basins are used to evaluate the factors that influence the hydrogen isotopic composition of methane, which is an important parameter in natural gas research and provides complementary information to that provided by carbon isotopes.
TL;DR: A novel method is reported to fabricate a nano-sponge which is composed of hydrophobic hydrocarbon and hydrophilic TiO2 nanoparticles for oil absorption or desorption that are responsive to UV irradiation that can be applied for oil-water separation, oil spill cleanup and reuse of spilled oil.
Abstract: Controlled surface wettability for oil has been intensively studied to remove industrial oil waste or oil spill pollution from seas or rivers In particular, external stimuli-induced special wetting materials, such as photo-responsive TiO2, have attracted considerable attention for oil-water separation In this study, a novel method is reported to fabricate a nano-sponge which is composed of hydrophobic hydrocarbon and hydrophilic TiO2 nanoparticles for oil absorption or desorption that are responsive to UV irradiation The hydrocarbon in the nano-sponge could selectively absorb oil from water, whereas the absorbed oil is released into the water by TiO2 in response to UV irradiation The nano-sponge functionalized porous polydimethylsiloxane released more than 98% of the absorbed crude oil with UV irradiation and air-bubbling It could be continuously reused while maintaining a high absorption capacity and desorption efficiency without incurring secondary air or water pollution This smart oil absorption/desorption methodology with excellent selectivity and recyclability with almost perfect removal of absorbed oil can be applied for oil-water separation, oil spill cleanup and reuse of spilled oil
TL;DR: In this paper, the kinetics of natural gas hydrate formation in the presence of dissolved salts (NaCl) and crude oil (a middle east crude with density 851.5 kg/m3) were investigated by using a standard rocking cell (RC-5) apparatus.
TL;DR: The results show that, at high temperatures, this olefinic fuel reacts rapidly, similar to related alkane fuels, but the pronounced thermal stability of the allylic pentenyl species inhibits low temperature reactivity, so 2M2B does not produce "cool flames" or negative temperature coefficient behavior.
Abstract: Two experimental studies have been carried out on the oxidation of 2-methyl-2-butene, one measuring ignition delay times behind reflected shock waves in a stainless steel shock tube, and the other measuring fuel, intermediate, and product species mole fractions in a jet-stirred reactor (JSR). The shock tube ignition experiments were carried out at three different pressures, approximately 1.7, 11.2, and 31 atm, and at each pressure, fuel-lean (ϕ = 0.5), stoichiometric (ϕ = 1.0), and fuel-rich (ϕ = 2.0) mixtures were examined, with each fuel/oxygen mixture diluted in 99% Ar, for initial postshock temperatures between 1330 and 1730 K. The JSR experiments were performed at nearly atmospheric pressure (800 Torr), with stoichiometric fuel/oxygen mixtures with 0.01 mole fraction of 2M2B fuel, a residence time in the reactor of 1.5 s, and mole fractions of 36 different chemical species were measured over a temperature range from 600 to 1150 K. These JSR experiments represent the first such study reporting detailed species measurements for an unsaturated, branched hydrocarbon fuel larger than iso-butene. A detailed chemical kinetic reaction mechanism was developed to study the important reaction pathways in these experiments, with particular attention on the role played by allylic C-H bonds and allylic pentenyl radicals. The results show that, at high temperatures, this olefinic fuel reacts rapidly, similar to related alkane fuels, but the pronounced thermal stability of the allylic pentenyl species inhibits low temperature reactivity, so 2M2B does not produce "cool flames" or negative temperature coefficient behavior. The connections between olefin hydrocarbon fuels, resulting allylic fuel radicals, the resulting lack of low-temperature reactivity, and the gasoline engine concept of octane sensitivity are discussed.