Decomposition Of Hexane Research Articles

Decomposition of hexane and benzene by dielectric barrier discharge plasma and reaction temperature: Comparison of performance of DC nano-second pulsed power supply and AC high voltage power supply

The VOC decomposition performance of a dielectric barrier discharge plasma powered by a DC nano-second pulsed power system was compared with that of an AC high voltage power system. Benzene and hexane were selected as a representative aromatic VOC and a chain-structured VOC, respectively, and the decomposition of each VOC was conducted at the same applied voltage in both systems. The energy of electrons released from the plasma was analyzed, and the ozone production ability was evaluated under a constant applied voltage at different temperatures. Compared with AC high voltage system, the DC nano-second pulsed power system had about 32 times, 26 times, and 30 times better performances for ozone production yield, benzene decomposition yield, and hexane decomposition yield, respectively. For benzene decomposition, the ring cleavage reaction was constant at all reaction temperatures. On the other hand, the mineralization of hexane was largely improved by higher temperatures, because the dehydrogenation reaction was accelerated. Consequently, benzene decomposition was easier than hexane decomposition at the same energy.

Oxidative removal of hexane from the gas stream by dielectric barrier discharge reactor and effect of gas environment

The removal of hexane from a gas stream using a dielectric barrier discharge (DBD) reactor was conducted at ambient temperature and atmospheric pressure. The role of N2, dry and humidified air carrier gases were investigated in terms of removal efficiency and product selectivity. The oxygen concentration was also varied over the range of 0 – 21% at constant power and residence time in an N2O2 mixture for further insight into oxygen's role. A semi-empirical model of NTP-decomposition in the presence of O2, N2 and H2O is proposed. It was observed that hexane removal efficiency and product selectivity increased with increasing plasma power, regardless of the carrier gas used. The maximum removal efficiency (hexane) was 94.4% in the humidified air carrier gas. The introduction of water vapour with a relative humidity of 25% at 20 °C in the plasma DBD system significantly increased the hexane removal efficiency and CO2 selectivity (84.7%) while eliminating the production of solid residue and O3. This was probably due to the action of OH radicals. Increasing O2 concentration from 0 to 21% increased the removal efficiency and CO2 selectivity due to the generation of oxygen radicals. The results imply that the decomposition of hexane by non-thermal plasma DBDs is dominated by the effect of OH and O radicals. A semi-empirical model shows that the non-thermal plasma decomposition of hexane is first order. The DBD reactor has been demonstrated to be an effective and promising technology for removing hexane emissions from air streams. The effects of N2, O2 and H2O have been quantified, and mechanisms for their action proposed.

Heterojunction-based two-dimensional N-doped TiO2/WO3 composite architectures for photocatalytic treatment of hazardous organic vapor

Two-dimensional nanosheet structures of N-doped TiO2/WO3 composites (WO3–N–TNSs) with varying WO3 loadings were synthesized by incorporating WO3 and N sources into sonochemically prepared TiO2 nanosheets (TNSs). These nanostructures were employed as photocatalysts, and their efficacy in the decomposition of hazardous hexane vapor was investigated. The photocatalytic efficiencies of the WO3–N–TNS composites were higher than those of N-doped TNS (N–TNS), which in turn were higher than the corresponding values for un-doped TNS. These variations were ascribed to the different light absorbance efficiencies, adsorption abilities, and charge carrier separations between the samples. An optimal WO3 loading for the performance of WO3–N–TNS was determined. Interestingly, the photocatalytic efficiency for hexane mixed with isopropyl alcohol (IPA) was lower than that for pure hexane, whereas the degradation efficiency for IPA did not vary with the feed method. Also investigated were the hexane conversion into CO2 over a representative WO3–N–TNS sample, the durability of the photocatalyst, and potential byproduct formation. Based on measurements of the hydroxyl radical population, a heterojunction-type mechanism was considered more plausible than a direct Z-scheme-type mechanism for the photocatalytic decomposition of hexane over the WO3–N–TNS photocatalysts.

Hexane decomposition without particle emission using a novel dielectric barrier discharge reactor filled with porous dielectric balls

This study investigated the decomposition of n-hexane in 15% O2 (N2 balance) in dielectric barrier discharge (DBD) reactors filled with three different kinds of dielectric balls, viz. quartz, less porous, and porous alumina balls. Products of n-hexane decomposition were analyzed by using a gas chromatograph (GC), gas chromatography–mass spectrometry (GC–MS), Fourier-transform infrared (FTIR) spectroscopy, and scanning mobility particle sizer (SMPS). The main products of n-hexane decomposition are CO, CO2, and liquid particles. The DBD reactor filled with porous alumina balls can completely adsorb the liquid particles and reduce particle emission. GC–MS and FTIR analysis results show that the liquid particles mainly compose 3-hexanone and 2-hexanone.

A green approach towards adoption of chemical reaction model on 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane decomposition by differential isoconversional kinetic analysis

This study investigated the thermal degradation products of 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexane (DBPH), by TG/GC/MS to identify runaway reaction and thermal safety parameters. It also included the determination of time to maximum rate under adiabatic conditions (TMRad) and self-accelerating decomposition temperature obtained through Advanced Kinetics and Technology Solutions. The apparent activation energy (Ea) was calculated from differential isoconversional kinetic analysis method using differential scanning calorimetry experiments. The Ea value obtained by Friedman analysis is in the range of 118.0–149.0kJmol−1. The TMRad was 24.0h with an apparent onset temperature of 82.4°C. This study has also established an efficient benchmark for a thermal hazard assessment of DBPH that can be applied to assure safer storage conditions.

Parameter Optimisation of Carbon Nanotubes Synthesis via Hexane Decomposition over Minerals Generated from Anadara granosa Shells as the Catalyst Support

The synthesis of carbon nanotubes (CNTs) by the chemical vapour deposition (CVD) method using natural calcite from Anadara granosa shells as the metal catalyst support was studied. Hexane and iron (Fe) were used as the carbon precursor and the active component of the catalyst, respectively. Response surface methodology (RSM) based on central composite design (CCD) was used to optimise the effect of total iron loading, the duration of reaction, and reaction temperature. The optimal conditions were total iron loading of 7.5%, a reaction time of 45 min, and a temperature of 850°C with a resulting carbon yield of 131.62%. Raman spectra, field‐emission‐scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses showed that the CNTs were of the multiwalled type (MWNTs).

Analysis of Catalytic Properties of Ni3Al Thin Foils for the Methanol and Hexane Decomposition

Intermetallic Ni3Al - based alloys belong to a group of advanced materials characterized by good chemical and physical properties (such as structural stability, corrosion resistance) which offer advenced technological applications. The paper presents the study of catalytic properties of Ni3Al foils (thickness approximately 50 &m) in the methanol and hexane decomposition. The egzamined material posses microcrystalline structure without any additional catalysts on the surface. The better catalytic activity of Ni3Al foils with respect to quartz plates in both methanol and hexane decomposition was confirmed. On thin Ni3Al foils the methanol conversion reaches approximately 100% above 480 o C while the hexane conversion reaches approximately 100% (98,5%) at 500 o C. Deposit formed during the methanol decomposition is built up of carbon nanofibers decorated with metal0like nanoparticles. Keywords—hexane decomposition, methanol decomposition, The choice of methanol as a substrate was caused by a possibility to produce hydrogen during its decomposition. Hexane is produced during the refining of crude oil. It is widely used in industry, but it is also one of the volatile organic compounds and can be decomposed by catalytic oxidation (10). The choice of hexane as a substrate was dictated by a possibility of using it as a method to purify the air.The aim of this study is to analyze the catalytic properties of Ni3Al thin foils for methanol and hexane decomposition. Ni3Al foil was used as a catalyst to produce hydrogen in methanol decomposition.

Synthesis and thermal stability of carbon-supported Ru–Ni core-and-shell nanoparticles

Binary nanoparticles of Ru–Ni supported on a carbon nanolayer and carbon-coated Ru–Ni core-and-shell nanoparticles were synthesized in a single step spray-pyrolysis process. A precursor containing ruthenium chloride and nickel chloride solution mixture was used to deposit Ru–Ni nanoparticles on a carbon nanolayer generated from hexane. Carbon-coated nanoparticles were produced by using ruthenium chloride and nickel chloride solution mixed with methanol and hexane as precursor in the spray-pyrolysis process. A carbon layer that was derived from the thermal decomposition of hexane and methanol forms a protective shell around the binary core-and-shell nanoparticles of Ru–Ni. TEM and EDS spectral graphs confirm the presence of carbon layers encapsulating the Ru–Ni nanoparticles. The encapsulating carbon layers are effective in reducing agglomeration of binary nanoparticles in the spray-pyrolysis process. The carbon-coated binary nanoparticles were subjected to heat treatment at temperatures up to 800 °C, the size and morphology of the nanoparticles before and after heat treatment were compared to examine the thermal stability of the nanoparticles. It was observed that the carbon-coated Ru–Ni nanoparticles exhibit unique thermal stability. EDS, SEM, and TEM data revealed that the morphology of the nanoparticles did not change during the heat treatment.

Study of Mechanism for Hexane Decomposition with Gliding Arc Gas Discharge

The mechanism of hexane decomposition under gliding arc gas discharge conditions is studied from both qualitative and quantitative analyses of its products for various hexane initial concentrations and different background atmospheres : nitrogen, argon, air (O2 21% N2 79% vol.) and N2–O2 mixtures. The decomposition rate, which decreases with increasing hexane initial concentration, can reach 94% when the carrier gas is air. Due to the electron energy consumed by the dissociation of nitrogen, the decomposition rate of hexane in nitrogen is lower than in argon. The radical channel plays a predominant role in the hexane decomposition process. With increasing oxygen concentration in the carrier gas, the hexane decomposition rate increases and promotes the conversion of CO– CO2, but it also leads to the formation of NO2.

Catalytic effect of Athabasca tar sand matrix on thermal decomposition of bitumen, hexene and hexane

The thermal decomposition of dichloromethane extracted Athabasca tar sand bitumen and Athabasca tar sand itself was studied in a stream of 30 ml/min helium at temperatures in the range 350–550°C. The volatile products obtained were analyzed by gas chromatography. It was observed that the products were mostly comprised of n-paraffins. Elemental analysis of the residues obtained from thermal decomposition indicated that decomposition was complete between 450°C and 500°C. The catalytic effect of sand, obtained by dichloromethane extraction of Athabasca tar sand, on the thermal decomposition of hexane and hexene was investigated at several temperatures. It was observed that the extracted sand had no catalytic effect on the decomposition of hexane and hexene up to 450°C, but catalyzed the thermal decomposition at 500°C or higher. The catalytic effect of the sand was fairly significant in the case of hexene. The products obtained from hexene decomposition were comprised of more than C 6 hydrocarbons. Hexane decomposition products contained C 6 or less than C 6 hydrocarbons.

Comparison studies of in situ loaded and impregnated silicalite-cobalt oxides

Data are presented which strongly indicate that cobalt has been incorporated into the framework of Silicalite. Experiments conducted to substantiate this claim are ion exchange, thermogravimetric, ammonia desorption, UV-visible spectrography, and catalytic activity for 2-propanol and hexane decomposition. Propylene is formed from 2-propanol for the hydrogen form of samples in situ loaded for cobalt compositions less than 4%. For hexane decomposition the reactions appear to be dehydrogenation of hexane to hexene and cracking of hexene to propylene followed by further decomposition to methane. The production of methane for samples with Co greater than 1% is high. However, the active sites for the in situ loaded catalyst are very difficult to reduce and appear to be different than the impregnated Co samples.

Hexane—carbon dioxide reaction catalyzed by alkaline earth metal oxides: II. Reaction network

The catalytic properties of alkaline earth metal oxides and the reaction sequences in the hexane-carbon dioxide reaction were investigated at 1173 K and atmospheric pressure. The catalytic activity for the decomposition of hexane to give deposited carbon increased with increase in the surface area of the catalyst, but the order of the activity for gasification of the deposited carbon was not parallel with either that for the decomposition of hexane or that for the hexane-carbon dioxide reaction. The catalytic activity for the hexane-carbon dioxide reaction was determined from the balance between the activity for the decomposition of hexane to produce the intermediate and that for the gasification of the deposited intermediate carbon. An oxygen transfer mechanism was applied to explain the gasification of carbon deposited on the catalyst surface. It was also confirmed that alkaline earth metal oxides catalyze the water-gas shift reaction under the gasification conditions. Based on these results, a network for the hexane-carbon dioxide reaction is proposed in order to understand comprehensively the catalysis of these oxides.

Gas-phase free radicals in the catalytic decomposition of hexane over tungsten. A modulated-beam mass spectrometric study

Desorption of alkyl and alkenyl (methyl, ethyl, allyl, and propyl) radicals from hot surfaces in the low-pressure (1 x 10^(12) - 8 x 10^(12) molecules cm^(-3) catalytic decomposition of hexane over W (1100-1800 K) and Pt (850-1400 K) has been studied by modulated-beam mass spectrometry. Time-of-flight analysis (phase spectrometry) of reaction products provided direct evidence about their identity. The effects of temperature, pressure, and surface treatment upon radical yields have also been investigated. Trapping of reactive species with iodine in a tandem reactor confirmed the presence of alkyl radicals. A mechanism is proposed in which free radicals, once formed, either desorb from the surface or decompose further into smaller fragments and olefins.

Low Temperature Steam Reforming Reaction of Hexane on Nickel Catalyst

The steam reforming of hexane was studied in the temperature range of 450∼500°C under the pressure of 1∼30atm by using nickel catalyst. The results obtained are summarized as follows:1) The equilibrium composition of products is determined by the following two reactions: i) CO+H2O_??_CO2+H2 ii) CO+3H2_??_CH4+H2O2) The rate determining step is involved in the decomposition of hexane by steam, and the reactions i) and ii) are fast.3) It is deduced that the reactant adsorbed on nickel is hexane and steam in gaseous phase or weakly adsorbed state reacts with the adsorbed hexane.

Strahlungschemie der Kohlenwasserstoffe. 7. Mitteilung. Jod in Hexan

AbstractThe radiolysis of hexane has been examined as a function of temperature and dose. Iodine has been used as scavenger to distinguish between radical and molecular reactions. The G‐values of the latter are independent of temperature, whereas the sum of the products derived from radical reactions increases with temperature. This means that the overall decomposition of hexane has a positive temperature coefficient. A temperature independent probability for primary bond fission forming either radicals or molecular products has been calculated.

A Comparison of the Decomposition of Hexane and Cyclohexane by Different Types of Radiation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA Comparison of the Decomposition of Hexane and Cyclohexane by Different Types of RadiationHarold A. Dewhurst and Robert H. SchulerCite this: J. Am. Chem. Soc. 1959, 81, 13, 3210–3212Publication Date (Print):July 1, 1959Publication History Published online1 May 2002Published inissue 1 July 1959https://doi.org/10.1021/ja01522a013RIGHTS & PERMISSIONSArticle Views47Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (281 KB) Get e-Alerts Get e-Alerts

The decomposition of n -hexane II. By reaction with atomic hydrogen

The reaction of hexane with hydrogen atoms produced by mercury photosensitization, has been studied in a flow system at 300° C. About one-third of the products had molecular weights greater than that of hexane, and dodecane was the main component of this product fraction. Hydrogen: hexane ratios up to 55:1 were employed and in these conditions virtually all the quenching of excited mercury atoms was brought about by hydrogen. The activation energy and steric factor of the reaction C 6 H 14 + H = C 6 H 13 + H 2 are estimated at 6 kcal and 10 -4 , respectively. These values are in accord with those recently obtained for the corresponding reactions involving other n -paraffins. The initial product distribution was similar to that obtained in the mercury photosensitized decomposition of hexane and the findings suggest that products of lower molecular weight than hexane derive almost completely from thermal decomposition of hexyl radicals. ‘Atomic cracking’ appears to be of little importance at these high temperatures.

The decomposition of n -hexane I. By mercury photosensitization

The mercury-photosensitized decomposition of hexane between 300 and 400° C has been studied in a flow system, the products being analyzed by gas chromatography. Under the experimental conditions employed, between one-third and one-half of the reacted hexane resulted in dodecane and other higher hydrocarbons. The yield of decomposition products per mole of hexane decomposed varied little with change of temperature, hexane pressure or time of reaction. The nature and distribution of these products can be accounted for by the decomposition scheme proposed by Kossiakoff & Rice, if radical addition and hydrogenation reactions are included.

Harry Walter Tyler

A pioneer in the history of science movement in the United States, H. W. TYLER devoted forty years of his life to the interests of the Massachusetts Institute of Technology, with which he was identified from his undergraduate days until he retired from active teaching. He was influential in promoting throughout the country improved methods of education in mathematics, and for many years he was engaged in organized effort to protect the freedom of academic thought and instruction. He was born April I6, 1863, of old New England rural stock in Ipswich, a small town of northern Massachusetts, to which his father, DAVID M. TYLER, had migrated from New Hampshire to engage in the business of watch-maker and jeweller. His mother, HARRIET WILLCOMB, was the daughter of a merchant of the town. At the age of seventeen, after preparation at the Ipswich High School and, it is said, reading Latin and Greek with the village minister, TYLER matriculated at the Massachusetts Institute of Technology, then in Boston. There he specialized in chenmistry, at the same time taking all the advanced courses that were offered in nmathematics, and serving on the editorial staff of a newspaper conducted by the undergraduates. Having presented a thesis on The Decomposition of Hexane at High Temperatures, he was graduated Bachelor of Science in i884; and, declining an assistantship in chemistry, was appointed Assistant in Mathematics. In I886 he was advanced to the grade of Instructor, and in 1887, having obtained leave of absence, he married a classmate, ALICE IRVING BROWN. They went abroad and he studied for a year at G6ttingen, where FELIX KLEIN was professor of mathematics, and then at Erlangen under PAUL GORDAN and MAX NOETHER. His dissertation was on Beziehungen zwischen der SYLVESTER'schen und der BizouT'schen Deternminante and he was admitted to the degree of Doctor of Philosophy in 1889. Returning to the Institute of Technology, TYLER served for a

Thermal Decomposition of Hexane at High Pressures

Thermal Decomposition of Hexane at High Pressures