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Showing 1 to 20 of 52 for “"Oxygenates"”.
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Alcohols and other oxygenates in automotive fuels
… RON base fuel in the blend. Most individual oxygenates showed similar effects in similar concentrations when their oxygen content was comparable. Blends containing more than one oxygenate showed some variation with methanol/MTBE/3 methylbutan-2-one and methanol/MTBE/4 methyl pentan-2-one …
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Degradation of gasoline oxygenates in the subsurface
… are compounds with the potential for use as oxygenates in reformulated gasolines. Being relatively soluble in water, these organics, if accidentally discharged into the subsurface, may rapidly spread and pose threats to groundwater. The purpose of this work was to evaluate the biodegradation …
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The effects of higher oxygenates on methanol synthesis
… of the feed gas on the behaviour of the higher oxygenates were also investigated by varying the feed gas composition.
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Computational thermochemistry of hydrocarbons, oxygenates, cyclic alkanes, and furans
Fundamental thermochemical properties including enthalpies ([Delta]H _{f 298}), entropies (S (T)), heat capacities (C_p(T)), and bond dissociation energies (BDEs) for several common and complex hydrocarbon fuel species are determined using computational chemical methods. [Delta]H _{f 298} values …
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Aromatization over platinum/zeolite L catalysts : the effect of oxygenates
… sulphur free. However, a substantial amount of oxygenates are formed in the Fischdr-Tropsch process and as yet no study has been undertaken to determine the effect of these compounds on the activity and selectivity of the catalyst.
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Cooperative activation of biomass-derived oxygenates with Lewis acid zeolites
Zeolites containing Sn, Ti, Zr, or Hf heteroatoms are versatile catalysts for the activation and conversion of oxygenated molecules owing to the unique Lewis acid character of their tetrahedral metal sites. Through fluoride-mediated synthesis, hydrophobic Lewis acid zeolites can behave as …
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Oxygenates in iron Fischer-Tropsch synthesis : is copper a selectivity promoter?
… to copper, and finally the co-feeding of C8 oxygenates, over a pure iron, and an iron catalyst promoted with 50 wt% copper, to investigate the mechanism and pathways of interaction. Co-precipitated iron-copper catalysts were prepared from their nitrates andsubsequently promoted with …
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Reaction chemistry of C₁ hydrocarbon fragments and oxygenates on Cr₂O₃ (101̅2)
The reactions of iodomethane, diiodomethane, and formaldehyde over stoichiometric, O-terminated, and Cl-terminated α-Cr₂O₃ surfaces, were studied by thermal desorption spectroscopy. Adsorbed formaldehyde forms dioxymethylene species on the nearly-stoichiometric surface that react primarily above …
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Interactions of biomass derived oxygenates with heterogeneous catalysts in aqueous and vacuum environments
Biomass is one of the most promising replacements for fossil fuels as a feedstock for chemical and transportation fuel production. The combination of low vapor pressure and high polarity of most biomass derived molecules makes water the ideal solvent for biomass upgrading reaction schemes. Metal …
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The effect of oxygenates on the oligomerisation of propene over zeolite ZSM-5
… are often contaminated with small amounts of oxygenates such as acetic acid, ethanol, butanol, methyl-ethyl-ketone (MEK), acetone and water. Complex feeds can result in competitive reaction between the feed components and may result in observed selectivities that cannot be predicted from pure …
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The effects of Fe(III) reduction on biodegradation of fuel oxygenates and chlorinated ethenes
Fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA), and chlorinated ethenes (TCE, cis-DCE and VC) are two groups of contaminants prevalent in groundwater systems. Fe(III) reducing conditions are dominant in many sedimentary environments. However, the effects of Fe(III) …
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Effect of ammonia co-feeding on oxygenates over K-Mo2C in the Fischer-Tropsch synthesis
… alcohols, aldehydes and carboxylic acids, i.e. oxygenates. Increasing the oxygenate selectivity was investigated in numerous studies as no commercial FT based process exists which produces oxygenates at a significant yield. Typically, transition metals such as Fe, Co, Rh and Ni are active for …
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Biodegradation of Fuel Oxygenates in Northeastern United States Aquifers with an Analysis of Underground Storage Tank Leaks
<p>During the past decade the application of monitored natural attenuation has become one of the predominant technologies used in the remediation of gasoline spills impacting subsurface soils and groundwater. The success of this method has depended, for the most part, on the biodegradation of those …
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Selective production of nitrogen-containing compounds via a modified Fischer-Tropsch process
… the NFTS process is enhanced by the presence of oxygenates. The studies, therefore, suggested that oxygenates are the primary precursors of NCCs. However, due to the gap in knowledge related to the NFTS reactions mechanisms, the validity of this assumption is still unknown. In this thesis, the …
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The effect of hydrocarbon exposure and temperature on the behaviour of elastomeric seals
… and heterocyclic), cycloparaffins, aromatic oxygenates and other oxygenates. Aromatic species were blended at 8% (v/v) while all other species were blended at 15% (v/v). Within the class of aromatic hydrocarbon components, it was found that decreasing molecular size, increasing the number of …
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Catalytic Process for the Conversion of Synthesis gas to Ethanol for Use as an Alternative Fuel
… precursor catalyst, but selectivity towards oxygenates was lower. In-situ FTIR results showed that CO adsorption takes place relatively weakly on the acetate precursor catalyst, owing to its high dispersion, as compared to the nitrate precursor catalyst. The weakly adsorbed CO on the acetate …
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Rhodium as a promoter for an iron Fischer-Tropsch catalyst
… with the view to enhance the formation of oxygenates. The base catalyst 100 Fe / 8.7 Cu 506 K2O / 372 Al2O3 was prepared by impregnation. Three catalysts with varying mass ratios of rhodium to iron (1.3 Rh/100 Fe; 2.4 Rh/100 Fe; 3.9 Rh/100 Fe) were prepared by incipient wetness impregnation …
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Effects of oxygenated fuels on DI diesel combustion and emissions
… future emission levels. Previous research on oxygenates has suggested the presence of molecular oxygen within the fuel significantly reduces the formation of particulate matter (PM). The PM reduction is logarithmic and correlates with the weight percent of oxygen in the fuel and not with other …
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Nitrogen-containing compounds from ammonia co-feed to the Fischer-Tropsch synthesis
… well as valuable chemicals such as olefins and oxygenates. In an attempt to produce additional chemicals in the FT reaction, this work investigates the synthesis of nitrogen containing compounds via ammonia addition to a low temperature, low pressure, slurry reactor using an unsupported, …
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The effect of different chemical classes on the swelling of NBR O-rings in blends with synthetic paraffinic kerosene
… of n-, iso- and cyclic paraffins, aromatics and oxygenates. The paraffins were tested as neat components. With the aromatics and oxygenates, 8% (v/v) blends with coal-to-liquid (CTL) SPK were prepared to simulate fully synthetic jet fuels that meet the minimum 8% aromatic specification. The data …
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