Hydrodeoxygenation and hydrocracking of oxygenated compounds over CuPd/γ-Al2O3–ZSM-5 catalyst

2021 ◽  
Author(s):  
Mihai Marinescu ◽  
Daniela Roxana Popovici ◽  
Dorin Bombos ◽  
Gabriel Vasilievici ◽  
Paul Rosca ◽  
...  
Keyword(s):  
Oxygenated Compounds

Effects of Ultrasounds on Neat nitrobenzene

2019 ◽  
Vol 70 (8) ◽  
pp. 3085-3088
Author(s):  
Carmen Eugenia Stavarache ◽  
Yasuaki Maeda ◽  
Mircea Vinatoru
Keyword(s):  
Nitro Group ◽  
Radical Cation ◽  
Reaction Mechanisms ◽  
Diphenyl Ether ◽  
Argon Atmosphere ◽  
Phenyl Radical ◽  
Dissolved Gas ◽  
Decomposition Products ◽  
Oxygenated Compounds ◽  
Phenyl Cation

Neat nitrobenzene was continuously irradiated at two ultrasonic frequencies: 40 and 200 kHz, under air and argon atmosphere, respectively. Samples taken at intervals of 1, 5, 10 and 24 h were analyzed by GC-MS and decomposition products were identified. Possible reaction mechanisms are discussed. Presence of air as dissolved gas leads to oxygenated compounds such as 1,4-benzoquinone, 2,4-dinitrophenol, m-dinitrobenzene while argon inhibits the decomposition of nitrobenzene, especially at sonication times under 5 h. Based on the nature of the compounds identified we advanced a mechanism, involving a divergent splitting of unstable radical cation of NB in air and argon respectively. Thus, under air, the phenyl cation formation is preferred leading to 1,4-benzoquinone nitro-biphenyls and dinitrobenzene, while under argon, the phenyl radical formation seems to be favored, leading to phenol and diphenyl ether. The oxygenated compounds detected under argon clearly are a consequence of the nitro group splitting.

ChemInform Abstract: Synthesis of Oxygenated Compounds Derived from Caryophyllene.

ChemInform ◽  
2010 ◽  
Vol 27 (7) ◽  
pp. no-no
Author(s):  
I. BOMBARDA ◽  
E. M. GAYDOU ◽  
J. SMADJA ◽  
R. FAURE
Keyword(s):  
Oxygenated Compounds

The Effect of Adding Oxygenated Compounds to Gasoline on Automotive Exhaust Emissions

2002 ◽  
Vol 125 (1) ◽  
pp. 344-350 ◽  
Author(s):  
S. G. Poulopoulos ◽  
C. J. Philippopoulos
Keyword(s):  
Octane Number ◽  
Combustion Engine ◽  
Methyl Tertiary Butyl Ether ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Research Octane Number ◽  
Oxygenated Compounds ◽  
Reid Vapor Pressure ◽  
Three Way Catalyst ◽  
Unregulated Emissions

In the present work, the effect of adding ethanol or methyl tertiary butyl ether (MTBE) to gasoline on the regulated and unregulated emissions from an internal combustion engine with a typical three-way catalyst was studied. The addition of ethanol to fuel (10% w/w) increased both the research octane number and the Reid vapor pressure of the fuel, whereas adding 11% w/w MTBE caused an increase only in the research octane number of the fuel. When the fuel contained MTBE, less hydrocarbons, carbon monoxide, and acetaldehyde were emitted in the tailpipe. The increased emissions of acetaldehyde and ethanol were the main disadvantages of using ethanol.

Hydrotreatment of pyrolysis oils from biomass: reactivity of the various categories of oxygenated compounds and preliminary techno-economical study

1996 ◽  
Vol 29 (1-4) ◽  
pp. 297-301 ◽  
Author(s):  
P. Grange ◽  
E. Laurent ◽  
R. Maggi ◽  
A. Centeno ◽  
B. Delmon
Keyword(s):  
Oxygenated Compounds ◽  
Pyrolysis Oils

Investigation of the Essential Oil of Ormenis africana from Morocco: Revision of Chemical Composition and Antibacterial Activity

2021 ◽  
Vol 1 (30) ◽  
pp. 34-38
Author(s):  
El Hanbali F Barrero A.F
Keyword(s):  
Antibacterial Activity ◽  
Essential Oil ◽  
Essential Oil Composition ◽  
Proteus Vulgaris ◽  
Oil Composition ◽  
Gram Negative ◽  
Main Compound ◽  
Oxygenated Compounds ◽  
Aerial Parts

Abstract- The essential oil composition from the aerial parts of Ormenis africana (Asteraceae), an endemic species from Morocco, has been investigated by GC/MS. A total of 31 compounds were identified, representing 77%. After fractionation by column chromatography, the main compound was isolated and its structure elucidated by NMR spectroscopy. The essential oil was dominated by oxygenated compounds with spathulenol (45.8%) followed by camphor (7.1%), -cadinol (5.9%) and -bisabolol (5.9%) as the main compounds. This oil can be classified as spathulenol-type according to its spathulenol content. In vitro the antibacterial activity of the whole essential oil against three Gram positive (Bacillus cereus, Enterococcus faecalis, Streptococcus C) bacteria and three Gram negative (Proteus vulgaris, Escherichia coli, Pseudomonas aeroginosa) bacteria, showed significant results. Keywords: Asteraceae, Ormenis africana, Essential oil, Spathulenol, Antibacterial activity.

scholarly journals Crystal structure of human mARC1 reveals its exceptional position among eukaryotic molybdenum enzymes

2018 ◽  
Vol 115 (47) ◽  
pp. 11958-11963 ◽  
Author(s):  
Christian Kubitza ◽  
Florian Bittner ◽  
Carsten Ginsel ◽  
Antje Havemeyer ◽  
Bernd Clement ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Catalytic Mechanism ◽  
Full Range ◽  
3D Structure ◽  
Cytochrome P450 Enzymes ◽  
Oxygenated Compounds ◽  
Online Databases ◽  
Starting Point ◽  
Wide Range ◽  
Nitrogen Containing Compounds

Biotransformation enzymes ensure a viable homeostasis by regulating reversible cycles of oxidative and reductive reactions. The metabolism of nitrogen-containing compounds is of high pharmaceutical and toxicological relevance because N-oxygenated metabolites derived from reactions mediated by cytochrome P450 enzymes or flavin-dependent monooxygenases are in some cases highly toxic or mutagenic. The molybdenum-dependent mitochondrial amidoxime-reducing component (mARC) was found to be an extremely efficient counterpart, which is able to reduce the full range of N-oxygenated compounds and thereby mediates detoxification reactions. However, the 3D structure of this enzyme was unknown. Here we present the high-resolution crystal structure of human mARC. We give detailed insight into the coordination of its molybdenum cofactor (Moco), the catalytic mechanism, and its ability to reduce a wide range of N-oxygenated compounds. The identification of two key residues will allow future discrimination between mARC paralogs and ensure correct annotation. Since our structural findings contradict in silico predictions that are currently made by online databases, we propose domain definitions for members of the superfamily of Moco sulfurase C-terminal (MOSC) domain-containing proteins. Furthermore, we present evidence for an evolutionary role of mARC for the emergence of the xanthine oxidase protein superfamily. We anticipate the hereby presented crystal structure to be a starting point for future descriptions of MOSC proteins, which are currently poorly structurally characterized.

scholarly journals NiMo-sulfide supported on activated carbon to produce renewable diesel

2017 ◽  
Vol 22 (1) ◽  
pp. 71 ◽  
Author(s):  
Juan Tapia ◽  
Nancy Y Acelas ◽  
Diana López ◽  
Andrés Moreno
Keyword(s):  
Activated Carbon ◽  
Batch Reactor ◽  
Liquid Hydrocarbon ◽  
Product Distribution ◽  
Impregnation Method ◽  
Carbon Supports ◽  
Gaseous Products ◽  
Oxygenated Compounds ◽  
Metal Support Interaction ◽  
Metal Support

Due to their weak polarity and large surface area, activated carbon supports have the potential to enhance the dispersion of metal-sulfides. It is expected that the absence of a strong metal-support interaction can result in the formation of a very active and stable Ni-Mo-S phase. In this study, catalysts with different amounts of nickel and molybdenum supported on a commercial activated carbon were prepared by a co-impregnation method and characterized by BET, XRF, and SEM techniques. The catalytic activity for hydroprocessing of Jatropha oil was evaluated in a batch reactor, and the composition of the liquid and gaseous products were determined. Results showed that gaseous products are mainly composed of high amounts of propane and small amounts of other light hydrocarbons (C1 to C5). Liquid hydrocarbon products consisted of a mixture containing mainly n-paraffins of C15-C18 and some oxygenated compounds. The catalysts with a mass fraction<br />of 3 % Ni, 15 % Mo (Ni3Mo15/AC) presented the highest selectivity toward C17-C18 hydrocarbons, with a product distribution similar to a commercial<br />alumina-supported Ni-Mo-S catalyst.

scholarly journals PERBANDINGAN METODE MICROWAVE HYDRODISTILLATION (MH) DAN MICROWAVE HYDRODIFFUSION AND GRAVITY (MHG) UNTUK MENGEKSTRAK MINYAK ATSIRI DARI KULIT JERUK

2017 ◽  
Vol 2 (1) ◽  
pp. 82
Author(s):  
Ayu Chandra Kartika Fitri ◽  
Fikka Kartika Widyastuti
Keyword(s):  
Essential Oil ◽  
Microwave Power ◽  
Citrus Fruit ◽  
Orange Peel ◽  
Quality Standard ◽  
Extraction Methods ◽  
Oil Composition ◽  
Citrus Peel ◽  
Oxygenated Compounds ◽  
Earth Gravity

One source of essential oil that has long been popular is a citrus fruit (Citrus aurantium). Results waste citrus peel around 500,000 tonnes per year. So the prospects for the utilization of waste orange peel are big enough to extract the essential oil. However, conventional extraction methods have drawbacks in terms of product quality, so to find solutions to these shortcomings, it is necessary to use the extraction method by Microwave Hydrodiffusion and Gravity (MHG). This method combines the use of microwave heating and physical phenomena (hydrodiffusi and earth gravity) at atmospheric pressure, without addition of organic solvents or water. In this study used fresh orange peel material 400 and 500 grams, two variable microwave power of 100 and 300 Watt and the extraction time for 15, 30, 45 and 60 minutes. To know the processing time and the microwave power effective method of MHG, oil composition was analyzed by GCMS to determine the amount of the fraction of oxygenated compounds. The larger of installed microwave power, the higher of operating temperature, so the %yield increases in a shorter time. From the comparison of energy consumed, the MHG method is give 30% more energy efficient than the Microwave Hydrodistillation (MHD) method. The use of microwaves does not change the physical properties of oil. The oil produced from the MHG method has a good quality because it has specific gravity and refractive index values that meet the EOA quality standard and has a greater oxygenated compounds content than the MHD method

scholarly journals Simulating organic species with the global atmospheric chemistry general circulation model ECHAM5/MESSy1: a comparison of model results with observations

2007 ◽  
Vol 7 (1) ◽  
pp. 127-202 ◽  
Author(s):  
A. Pozzer ◽  
P. Jöckel ◽  
H. Tost ◽  
R. Sander ◽  
L. Ganzeveld ◽  
...  
Keyword(s):  
General Circulation Model ◽  
Atmospheric Chemistry ◽  
General Circulation ◽  
Circulation Model ◽  
Oxygenated Compounds ◽  
Reference Simulation ◽  
Sensitivity Studies ◽  
Systematic Biases ◽  
Using Data ◽  
Prior Analysis

Abstract. The atmospheric-chemistry general circulation model ECHAM5/MESSy1 is evaluated with observations of different organic ozone precursors. This study continues a prior analysis which focused primarily on the representation of atmospheric dynamics and ozone. We use the results of the same reference simulation and apply a statistical analysis using data from numerous field campaigns. The results serve as a basis for future improvements of the model system. ECHAM5/MESSy1 generally reproduces the spatial distribution and the seasonal cycle of carbon monoxide (CO) very well. However, for the background in the northern hemisphere we obtain a negative bias (mainly due to an underestimation of emissions from fossil fuel combustion), and in the high latitude southern hemisphere a yet unexplained positive bias. The model results agree well with observations of alkanes, whereas severe problems in the simulation of alkenes are present. For oxygenated compounds the results are ambiguous: The model results are in good agreement with observations of formaldehyde, but systematic biases are present for methanol and acetone. The discrepancies between the model results and the observations are explained (partly) by means of sensitivity studies.

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