Showing papers on "Aromatic hydrocarbon published in 2017"

Aromatic Hydrocarbon Production from Eucalyptus urophylla Pyrolysis over Several Metal‐Modified ZSM‐5 Catalysts

Abstract: Metal-modified HZSM-5 catalysts were prepared by the ion exchange of NH4ZSM-5 (SiO2/Al2O3=23) using Zn, Ga, Ni, and combinations thereof. The prepared catalysts were used to evaluate catalytic pyrolysis for the conversion of Eucalyptus urophylla to fuels and chemicals, specifically aromatic hydrocarbons, by using a micro-scale pyrolysis reactor coupled with GC–MS. Two different biomass-to-catalyst ratios (1:5 and 1:10 w/w) were studied. The catalyst prepared with Ga by total ion exchange (Ga-HZSM-5 B, ≈7 wt % Ga) yielded the highest amount of aromatic hydrocarbons, whereas the catalysts modified with Ni produced the lowest yield of aromatic hydrocarbons. A correlation between the methane yield and benzene and p-xylene selectivity was found for the catalysts, which was observed mainly for the Ni-, Zn-, and Ga-Ni-modified catalysts. The Ga-modified catalysts were the most selective for xylenes, whereas the Ni-based catalysts were the most selective for benzene production with a concurrent increase in methane production. The Zn-modified catalysts were the most selective for toluene production.

Symmetric or semi-symmetric compounds useful as immunomodulators

Abstract: A compound having Formula I:(I), or a pharmaceutical acceptable salt thereof. A is a bivalent arene or a bivalent heteroarene; Ring B and Ring B' are independently a 6-membered aromatic hydrocarbon ring, a 6-membered heterocyclic ring, a 8- to 10-membered aromatic hydrocarbon ring, or a 8- to 10-membered heterocyclic ring; Y and Y' are independently, null (direct bond), -CHR 1 -, -CH 2 -CH 2 -, -NR 1 -, -0-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -SOCH 2 -, -CH 2 SO-, or -SO 2 CH 2 -, and R 1 is H, C 1-6 alkyl, or C 3-6 cycloalkyl.

Tandem μ-reactor-GC/MS for online monitoring of aromatic hydrocarbon production via CaO-catalysed PET pyrolysis

Abstract: The present work demonstrates the online monitoring of aromatic hydrocarbon production via two-step CaO catalysed pyrolysis of poly(ethylene terephthalate) (PET), employing tandem μ-reactor-gas chromatography/mass spectrometry (TR-GC/MS). PET produces high-boiling terephthalic acid (TPA) during pyrolysis, which hinders the online monitoring of PET pyrolysis. In this work, TR allowed for independent control of the PET pyrolysis and CaO catalytic reaction with a very small sample loading (<1 mg) and split injection into the GC/MS (split ratio 100 : 1) system; thus, fatal line clogging by TPA could be avoided. Thus, we successfully demonstrated the effect of CaO basicity on the time- and temperature-dependent dynamic production of aromatic hydrocarbons. Strongly basic CaO accelerated the decarboxylation of PET pyrolysates to afford useful aromatic hydrocarbons such as benzene, toluene, and styrene with 99.7% selectivity in the oil. In contrast, weakly basic CaO enhanced benzophenone production in preference to benzene formation. The poor deoxygenation ability of the weakly basic CaO increased the concentration of oxygen-containing compounds in the oil. Finally, the time- and temperature-dependent dynamic pathways and the mechanism involving strongly basic/weakly basic CaO were established. These findings allow for a clearer understanding of the nature of PET catalytic pyrolysis, which will be helpful for advancing PET recycling. Furthermore, the novel methodology—online monitoring of a two-step pyrolysis–catalytic upgrading process involving high-boiling compounds—will gain the highest demand in the fields of green chemistry and reaction engineering.

2H-Dinaphthopentacene: A Polycyclic Aromatic Hydrocarbon Core for Metal-Free Organic Sensitizers in Efficient Dye-Sensitized Solar Cells.

Abstract: Continuous studies on the use of a polycyclic aromatic hydrocarbon as the central block of an organic photosensitizer have brought forth a new opportunity toward efficiency enhancement of dye-sensitized solar cells (DSCs). In this paper, a nonacyclic aromatic hydrocarbon 9,19-dihydrodinaphtho[3,2,1-de:3',2',1'-op]pentacene, tethered with four 4-hexylphenyl solubilizing groups is reported. The novel chromophore 9,9-19-19-tetrakis(4-hexylphenyl)-9,19-dihydrodinaphtho[3,2,1-de:3',2',1'-op]pentacene is further functionalized with diarylamines and 4-(7-ethynylbenzo[c][1,2,5]thiadiazol-4-yl)benzoic acid to produce two donor-acceptor (D-A) organic photosensitizers, achieving good power conversion efficiencies up to 10.2% in DSCs.

Aromatic Hydrocarbon Production and Catalyst Regeneration in Pyrolysis of Oily Sludge Using ZSM-5 Zeolites as Catalysts

Abstract: ZSM-5 zeolites were selected as catalysts to promote the aromatization during pyrolysis of oily sludge. The total aromatic yield and product distribution were investigated to evaluate the efficiency of the catalysts and the influence of operating condition. The fresh and used catalysts were characterized by means of scanning electron microscopy, inductively coupled plasma optical emission spectrometry, X-ray diffraction, and ammonia temperature-programmed desorption. Results show that the highest catalytic activity (93.37%) was achieved with ZSM-5-O [the silicon/aluminum ratio (SAR) is 19] at a retention time of 40 s. The total aromatic yield increases with a longer retention time and higher catalyst dosage. An increase in the SAR value of ZSM-5 zeolites will reduce its acid density and aromatization activity. The coke deposition leading to deactivation for zeolites was observed, and calcination was used to regenerate the original catalytic performance. After regeneration, crystallinity was not affected b...

Catalytic conversion of guaiacol as a model compound for aromatic hydrocarbon production

Abstract: Guaiacol, a mono-aromatic compound containing a hydroxyl and a methoxyl group, is one of the main products from lignin pyrolysis. In order to investigate the feasibility of aromatic hydrocarbons production from lignin, guaiacol was employed as the model compound for the catalytic conversion over HZSM-5 zeolites with different Si/Al ratios in a fixed-bed reactor under the temperatures from 500 °C to 800 °C. With the increased temperature, the yield of both aromatic hydrocarbons (such as benzene, toluene, styrene, naphthalene and 2-methylnaphtalene) and coke was increased from the mass fraction of 1.83%–24.27% and from 1.17% to 12.81%, respectively. At 600 °C, the yield of benzene was promoted by the HZSM-5 catalyst with high Si/Al ratio (200) by the mass fraction of 2.94% and up to 1.94% for that of toluene. The production of monocyclic aromatic hydrocarbons (especially for benzene and p-xylene) was favored with the loading of Ni on HZSM-5(25), while the formation of polycyclic aromatic hydrocarbons was notably inhabited. The coke deposition was slightly increased with the increased loading of Ni during the catalytic conversion of guaiacol. The demethoxylation and dehydroxylation reactions were considered to be promoted by the increase of Bronsted acid sites, while the methyl substitution reaction was slightly influenced by the total acidity of catalyst. The experimental results provided the conceptual and technical support for the catalytic pyrolysis of lignin to produce aromatic hydrocarbons.

A Perylene‐Based Polycyclic Aromatic Hydrocarbon Electron Donor for a Highly Efficient Solar Cell Dye

Abstract: The continuing efforts of creating novel polycyclic aromatic hydrocarbons (PAHs) and exploiting them as the crucial building-blocks of organic donor-acceptor (D-A) dyes with excellent excited state features, should bring an unprecedented chance for the improvement of power conversion efficiency (PCE) of dye-sensitized solar cells (DSCs). In this paper we report a nonacyclic aromatic hydrocarbon, N-annulated benzoindenopentaphene (NBIP), which can be tethered with multiple solubilizing groups including one 2-hexyldecyl, one 2-hexyldecyloxy, and four 4-hexylphenyl substituents. The side- and end-chain functionalized NBIP can be conveniently prepared at an excellent yield, and further cross-coupled with 4-(7-ethynylbenzo[c][1,2,5]thiadiazol-4-yl)benzoic acid to afford a metal-free D-A dye C293, achieving a high power conversion efficiency of 12.6% under the AM1.5G condition, in DSCs without use of any coadsorbent.

Group additive modeling of substituent effects in monocyclic aromatic hydrocarbon radicals

Abstract: The thermodynamic properties of the unsubstituted and substituted phenyl, phenoxy, anisyl, benzoyl, styryl and benzyl radicals with six substituents (hydroxy, methoxy, formyl, vinyl, methyl, and ethyl) are calculated with the bond additivity corrected (BAC) post-Hartree-Fock G4 method. Bond dissociation energies of monocyclic aromatic hydrocarbons are calculated and used to identify substituent interactions in these radicals. Benson's Group Additivity (GA) scheme is extended to aromatic radicals by defining 6 GAV and 29 NNI parameters through least squares regression to a database of thermodynamic properties of 369 radicals. Comparison between G4/BAC and GA calculated thermodynamic values shows that the standard enthalpies of formation generally agree within 4 kJ mol−1, whereas the entropies and the heat capacities deviate less than 4 J mol−1 K−1. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2089–2106, 2017

Investigation of aromatic hydrocarbon inclusion into cyclodextrins by Raman spectroscopy and thermal analysis

Abstract: Among various cavitand molecules, cyclodextrins are extensively studied due to their ability to form host-guest complexes with small hydrophobic molecules. Aiming to explore cyclodextrin implementation on the scopes related to the environmental pollution monitoring or remediation, extensive studies for understanding the cyclodextrin-based host-guest complex formation with selected targeted substances are conducted. In this context, two polycyclic aromatic hydrocarbons, naphthalene and fluoranthene as well as toluene as a member of volatile organic compounds, were studied regarding their ability to encapsulate into cyclodextrin cavities. Synthesised complexes were examined by thermogravimetric analysis combined with Raman spectroscopy. The obtained results demonstrated that the size between targeted molecules and the cyclodextrin cavities strongly correlates with its ability to engage in complexation. Thus, this latter parameter plays an important role in the inclusion complex formation as well as in the strength of the interaction between the molecules.

Recombination of aromatic radicals with molecular oxygen

Abstract: The addition of molecular oxygen to hydrocarbon radicals yields peroxy radicals (ROO), which are crucial species in both atmospheric and combustion chemistry. For aromatic radicals there is little known about the recombination kinetics, especially for the high temperatures of relevance to combustion. Here, we have employed direct CASPT2 based variable reaction coordinate transition state theory to predict the high pressure recombination rates for four prototypical aromatic hydrocarbon radicals: phenyl, benzyl, 1-naphthyl, and 2-naphthyl. The variation in the predicted rates is discussed in relation to their molecular structure. The predicted rate coefficients are in reasonably satisfactory agreement with the limited experimental data and are expected to find utility in chemical modeling studies of PAH growth and oxidation.

Room temperature magnetoresistance in an organic spin valve with an aromatic hydrocarbon macrocycle

Abstract: Aromatic hydrocarbon macrocycles, which have a conjugated π-electron system, are potentially useful for various organic device applications, although there have been no attempts to apply them to organic spin valves (OSVs). Here, we studied OSVs with [6]cyclo-2,7-naphthylene (CNAP), a type of aromatic hydrocarbon macrocycle. OSV stacking structures of Co/AlOx/CNAP/Ni80Fe20 with different CNAP thicknesses were fabricated, and the transport properties of the OSVs were measured from 300 to 5 K. A magnetoresistance of approximately 1%-2% at 300 K (4%-6% at 5 K) was observed for 15-nm-thick OSVs, showing the potential for organic spintronics based on aromatic hydrocarbon macrocycles.

A simple method to determine the surface energy of graphite

Abstract: Graphite is a material condensed from aromatic hydrocarbon that forms an infinite plane that exhibits an amphoteric feature. Structurally, a number of benzene rings form a solid planar sheet. A...

Catalyst for high-selectivity preparation of light aromatic hydrocarbon by using synthesis gas and preparation method thereof

Abstract: The invention provides a catalyst for high-selectivity preparation of light aromatic hydrocarbon by using synthesis gas and a preparation method thereof and belongs to the field of catalysts The catalyst is prepared from, by mass, 20%-60% of modified zeolite molecular sieve and 40%-80% of zirconium-containing composite oxide The preparation method comprises the steps that the zirconium-containing composite oxide is added to a solvent, and ultrasonic dispersion is performed to obtain a solution A; the modified zeolite molecular sieve is added into the solution A; the mixture obtained after ultrasonic dispersion is subjected to suction filtration, and the obtained filter cake after washing is dried; the sample obtained after drying is grinded into powder; the powdery sample is calcinated, and the obtained sample is the catalyst for high-selectivity preparation of the light aromatic hydrocarbon by using synthesis gas The light aromatic hydrocarbon can be prepared in a high-selectivity mode, and the stability is good The preparation method of the catalyst for high-selectivity preparation of the light aromatic hydrocarbon by using the synthesis gas is simple and low in cost and has good industrial application prospect

Deuterium Isotope Effects in Polymerization of Benzene under Pressure

Abstract: The enormous versatility in the properties of carbon materials depends on the content of the sp2 and sp3 covalent bonds. Under compression, if intermolecular distances cross a critical threshold, then unsaturated hydrocarbons gradually transform to saturated carbon polymers. However, the mechanism of polymerization, even for benzene, the simplest aromatic hydrocarbon, is still not understood. We used high-pressure synchrotron X-ray, neutron diffraction, and micro-Raman spectroscopy together with density functional calculations to investigate the isotope effects in benzene isotopologues C6H6 and C6D6 up to 46.0 GPa. Raman spectra of polymeric products recovered from comparable pressures show the progression of polymerization exhibiting a pronounced kinetic isotope effect. Kinetically retarded reactions in C6D6 shed light on the mechanism of polymerization of benzene. We find that C6D6-derived products recovered from P < 35 GPa actively react with moisture, forming polymers with higher sp3 hydrogen contents...

Microbial Degradation of Aromatic hydrocarbon: Naphthalene through Nocardiopsis alba RD3

Abstract: Polycyclic aromatic hydrocarbons (PAHs) contain two or more benzene rings in their structure, which are hydrophobic and have lower solubility than the mono aromatics. PAHs are generally contaminating the environment as a result of oil refinery discharge, accidental oil spill or weathering of creosote-impregnated pylons (Coates, 2004). Naphthalene is an organic compound with chemical formulaC10H8. It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odour that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene structure consists of a fused pair of benzene rings. It is best known as the main ingredient of traditional mothballs. Naphthalene is the most abundant single component of coal tar. Although the composition of coal tar varies with the coal from which it is produced, typical coal tar is about 10% naphthalene by weight. In industrial practice, distillation of coal tar yields oil containing about 50% naphthalene, International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 7 (2017) pp. 1174-1181 Journal homepage: http://www.ijcmas.com

Effect of Acidity and Manner of Addition of HZSM-5 Catalyst on the Aromatic Products during Catalytic Upgrading of Biomass Pyrolysis

Abstract: To investigate the effects of acidity on aromatic yield and selectivity during the catalytic pyrolysis of biomass, the silica to alumina ratio (SAR), as well as the amount and addition method of HZSM-5 catalyst were varied. The results showed that with an increase in the SAR, the pore volume was reduced, the average pore diameter of the HZSM-5 catalyst increased, and the total acidity and catalytic activity decreased. Meanwhile, the increase in acidity led to an increased non-condensable gases yield, which was associated with a decrease in the bio-oil yield. The calorific value and moisture content increased, and the ability of deoxygenation was enhanced. The single ring aromatic hydrocarbons (BTXE) content increased, and the polycyclic aromatic hydrocarbons (2-ring, 3-ring) content decreased noticeably. The selectivity of BTXE decreased substantially from 69 wt.% to 6.85 wt.%, while the selectivity of naphthalene and its derivatives increased remarkably, as the SAR increased. Additionally, the acidity increased the selectivity of unsubstituted aromatic compounds, but decreased the selectivity of substituted aromatic compounds. Moreover, ex situ catalytic pyrolysis more effectively enhanced the aromatic hydrocarbon yield and selectivity (69 wt.%) compared with in situ catalytic pyrolysis (27.51 wt.%), and in situ catalytic pyrolysis generated more polyaromatics and solid residue.

Electronic device material, organic electroluminescent element, display device, and illuminating device

Abstract: PROBLEM TO BE SOLVED: To provide an electronic device material high in thermodynamic stability.SOLUTION: An electronic device material has a structure represented by a general formula (1), of which the absolute value ΔEst of the difference between the lowest excited singlet energy level and the lowest excited triplet energy level is 0.90 eV or less. In the general formula (1), Xand Xindependently represent NR, an oxygen atom or a sulfur atom; Rrepresents a hydrogen atom, a chain alkyl group, a cyclic alkyl group, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group; Yrepresents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; and Rto Rindependently represent a hydrogen atom or a substituent group.SELECTED DRAWING: None

Antibiotic and Heavy Metal Tolerance of Some Indigenous Bacteria Isolated From Petroleum Contaminated Soil Sediments with A Study of Their Aromatic Hydrocarbon Degradation Potential

Abstract: Production, refinery, transportation or storage of crude oil and its derivatives, through accidental leakages may lead to contamination of soils with BTEX compounds (benzene, toluene, ethyl-benzene and xylenes), polycyclic aromatic hydrocarbons (PAHs), as well as aliphatic hydrocarbons. Oil wells, petroleum plants, distribution and storage devices, transportation equipments are the main sources of the contaminations (Wolicka et al., 2009). Because trace heavy metals are common constituents of crude oil (Osuji and Onojake, 2004) and of petroleum derivatives (Pb 2+ leaded gasoline, lubricating oils and greases; Zn 2+ , Cd 2+ compounds amended engine oil etc.) during an increased, long term pollution with hydrocarbons the heavy metal contamination of the respective areas should also be taken into account (John, 2007). Furthermore, within huge industrial areas (mining, metallurgical, oil distribution industry etc.) where hydrocarbon spills are very common the co-occurrence of hydrocarbon and heavy metal pollutants is observed (Abdullah et al., 2011).

Low eutectic solvent for aromatic hydrocarbon separation and application thereof to extractive distillation

Abstract: The invention discloses a low eutectic solvent for aromatic hydrocarbon separation. The low eutectic solvent is obtained by mixing hydrogen bond receptors and hydrogen bond donors according to a certain ratio (the molar ratio of 1: 1 to 1:10), and stirring till being in a uniform transparent state at 70-100 DEG C. The low eutectic solvent is low in toxicity, environment-friendly and high in efficiency, and can be applied to the process of separating aromatic hydrocarbons from non-aromatic hydrocarbons in coal tar and petroleum oil.

Method for producing high-octane petrol from catalytic cracking diesel oil

Abstract: The invention relates to the field of petroleum refining, and in particular relates to a method for producing high-octane petrol from catalytic cracking diesel oil. The method comprises the following steps: hydrofining and refining catalytic cracking diesel oil, separating the catalytic cracking diesel oil into a fraction less than 280 DEG C and a fraction greater than 280 DEG C, and performing aromatic extraction on the fraction greater than 280 DEG C so as to obtain extract oil rich in aromatic hydrocarbon and raffinate oil rich in alkane; performing catalytic cracking on the fraction less than 280 DEG C and the raffinate oil rich in alkane so as to obtain high-octane petrol rich in aromatic hydrocarbon; and performing aromatic hydrocarbon utilization on the extract oil rich in aromatic hydrocarbon. By adopting the method, side chains of mononuclear aromatics with side chains, mononuclear aromatics with relatively short side chains and bicyclo-aromatic hydrocarbon with side chains can be broken and are sufficiently utilized, and then the high-octane petrol can be produced.

Aromatic Hydrocarbon Generation from a Simulated Bio-oil Fraction by Dual-stage Hydrogenation-cracking: Hydrogen Supply and Transfer Behaviors

Abstract: The improvement of the hydrogen-poor composition of bio-oil is important for its cracking to produce aromatic hydrocarbons. In this work, a mild hydrogenation pre-treatment and methanol cocracking were combined to implement proper hydrogen supplementation for cracking. Acetic acid (HAc), hydroxypropanone (HPO), and cyclopentanone (CPO) were selected as model compounds and mixed to prepare a simulated distilled fraction (SDF) of bio-oil. The hydrogen supply and transfer behaviours in hydrogenation-cracking were investigated. For the conversion of individual components: HAc was difficult to be hydrogenated, and therefore in the cracking stage, the conversion and oil phase yield were low; ketones were successfully hydrogenated to alcohols, and thus high aromatic hydrocarbon yields were achieved. Hydrogenation-cracking of SDF showed that the inferior performance of HAc was improved by an internal hydrogen transfer, namely the alcohols produced from ketones supplied hydrogen for HAc conversion. However, because of the high HAc content in SDF, this hydrogen supplement was not sufficient. Therefore, methanol (MeOH) was used as the coreactant for secondary hydrogen supply. The integral efficient conversion of SDF and MeOH to aromatic hydrocarbons was achieved when the MeOH blending ratio was 30%. Finally, a reaction mechanism of hydrogenation-cocracking was proposed.

Ion liquid cross-linked polymer supported nanometer palladium metal catalytic material, preparation method and applications thereof

Abstract: The present invention discloses an ion liquid cross-linked polymer supported nanometer palladium metal catalytic material, which is short for P(DVB-DIIL)-Pd, and has the structure defined in the specification. The invention further discloses a preparation method of the catalytic material, and applications of the catalytic material in preparation of aromatic amine compounds through liquid phase catalytic hydrogenation of nitro aromatic hydrocarbons. According to the present invention, the ion liquid cross-linked polymer supported nanometer palladium metal catalytic material can provide high catalytic selectivity and high conversion rate for the liquid phase hydrogenation reactions of a variety of nitro aromatic hydrocarbon compounds, and can be recycled.

Process for Producing Paraxylene by Methylation of Benzene and/or Toluene

Abstract: A process is described for producing paraxylene, in which an aromatic hydrocarbon feedstock comprising benzene and/or toluene is contacted with an alkylating reagent comprising methanol and/or dimethyl ether in an alkylation reaction zone under alkylation conditions in the presence of an alkylation catalyst to produce an alkylated aromatic product comprising xylenes. The alkylation catalyst comprises a molecular sieve having a Constraint Index≤5, and the alkylation conditions comprise a temperature less than 500° C. Paraxylene may then be recovered from the alkylated aromatic product.