Showing papers on "Aromatic hydrocarbon published in 2020"
TL;DR: In this paper, the effect of biomass to catalyst loading ratio on aromatic hydrocarbon production was evaluated using pyrolysis of pinewood sawdust over acidic (ZSM-5) and basic (CaO) catalyst.
Abstract: A higher amount of oxygenates is the main constraint for higher yield and quality of aromatics in catalytic pyrolysis while a study of hydrocarbon production with a balance of reactive species lies importance in the catalytic upgrading of pyrolytic vapor. Catalytic pyrolysis of pinewood sawdust over acidic (ZSM-5) and basic (CaO) catalyst was conducted by means of Py-GC/MS to evaluate the effect of biomass to catalyst loading ratio on aromatic hydrocarbon production. Catalytic pyrolysis with four different biomass to catalyst ratios (0.25:1, 0.5:1, 1:1, and 2:1) and non-catalytic pyrolysis were conducted. It has been obtained that ZSM-5 showed better catalytic activity in terms of a high fraction of aromatic hydrocarbon. The ZSM-5 catalyst showed a potential on the aromatization as the yield of aromatic hydrocarbon was increased with a higher amount of ZSM-5 catalyst and the highest yield of aromatics (42.19 wt %) was observed for biomass to catalyst ratio of 0.25:1. On the other hand, basic CaO catalyst was not selective to aromatic hydrocarbon from pinewood sawdust but explored high deacidification reaction in pyrolytic vapor compared to ZSM-5 catalyst, whereas non-catalytic pyrolysis resulted in acidic species (13.45 wt %) and phenolics (46.5 wt %). Based on the results, ZSM-5 catalyst can only be suggested for catalytic pyrolysis of pinewood sawdust for aromatic hydrocarbon production.
61 citations
TL;DR: In this paper, a metal-modified HZSM-5 zeolite catalysts were used for light aromatic compounds (BTX: benzene, toluene and xylenes) in the catalytic cycle.
59 citations
TL;DR: In this article, three co-feeders, i.e., methanol, polyethylene terephthalate (PET) and calcium formate, were employed for comparative pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments to evaluate their hydrogen supply abilities.
Abstract: Catalytic fast pyrolysis of pine over HZSM-5 was conducted with different hydrogen-rich co-feeders aiming at increasing the production of monocyclic aromatic hydrocarbons (MAHs) while suppressing the formation of polycyclic aromatic hydrocarbons (PAHs). Three co-feeders, i.e., methanol, polyethylene terephthalate (PET) and calcium formate, were employed for comparative pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments to evaluate their hydrogen supply abilities. The results indicated that calcium formate exhibited the best ability to substantially promote the conversion of biomass into MAHs. Under the optimal conditions of a calcium formate : pine ratio of 3 : 1 at 650 °C, the yields of MAHs and PAHs were 10.65 wt% and 1.94 wt% respectively, compared with 9.23 wt% and 2.49 wt% without calcium formate, respectively. Moreover, laboratory-scale catalytic fast pyrolysis experiments were performed to examine the pyrolytic product and aromatic hydrocarbon distribution at different calcium formate to pine ratios and pyrolysis temperatures. The yields of MAHs and PAHs were 7.80 wt% and 1.70 wt% in the absence of calcium formate, which were then increased to 9.45 wt% and 1.14 wt% respectively under the optimal conditions of 650 °C and a calcium formate : pine ratio of 1 : 2. A catalyst stability test was also conducted to confirm that calcium formate helped maintain the catalyst activity. In addition, the possible hydrogen supply mechanism of calcium formate was speculated.
49 citations
TL;DR: Az-BN-1 and Az-BN -2 exhibit unexpected deboronization upon addition of trifluoroacetic acid, which distinguishes them from other reported BN-heteroaromatics and can be ascribed to the unique property of azulene unit.
Abstract: Azulene, a nonalternant bicyclic aromatic hydrocarbon, has unique chemical and physical properties and is considered to be a promising building block for constructing novel polycyclic aromatic hydrocarbons (PAHs) and heteroaromatics. We present here the first two azulene-based BN-heteroaromatics Az-BN-1 and Az-BN-2. The chemical structures and optical and electrochemical properties of both compounds have been investigated, as well as their sensing behavior in response to fluoride ion. Az-BN-1 and Az-BN-2 show different photophysical properties from other reported BN-embedded PAHs, such as lower band gaps and unusual fluorescence. In addition, Az-BN-1 and Az-BN-2 exhibit unexpected deboronization upon addition of trifluoroacetic acid, which distinguishes them from other reported BN-heteroaromatics and can be ascribed to the unique property of the azulene unit.
45 citations
TL;DR: Experimental results indicated that Fe-Ce@Al2O3 prepared by co-precipitation possessed superior catalytic activity due to its high content of weak acid sites, large pore volume, high surface area, and well dispersion, leading to a ~3-fold increase in targeted monocyclic aromatic hydrocarbons compared to that achieved non-catalytically.
Abstract: Converting polycarbonate (PC) plastic waste into value-added chemicals and/or fuel additives by catalytic pyrolysis is a promising approach to dispose of solid wastes. In this study, a series of Fe-Ce@Al2O3 metal oxides were prepared by coprecipitation, impregnation, and a direct mixing method. The synthesized catalysts were then employed to investigate the catalytic conversion of PC wastes to produce aromatic hydrocarbons. Experimental results indicated that Fe-Ce@Al2O3 prepared by coprecipitation possessed superior catalytic activity because of its high content of weak acid sites, large pore volume, high surface area, and well dispersion of Fe and Ce active species, leading to an ∼3-fold increase in targeted monocyclic aromatic hydrocarbons compared to that achieved noncatalytically. Moreover, an increase in the catalyst to feedstock (C/F) mass ratio was beneficial to the production of aromatic hydrocarbons at the expense of phenolic products, and elevating the C/F ratio from 1:1 to 3:1 considerably increased the benzene formation as the enhancement factor was increased from 2.3 to 8.8.
31 citations
TL;DR: In this article, poly(ethylene terephthalate) (PET) pyrolysis products and those produced from their subsequent catalytic reactions under various metal oxides (ZnO, MgO, TiO2, and ZrO2) were evaluated qualitatively.
Abstract: Poly(ethylene terephthalate) (PET) pyrolysis products and those produced from their subsequent catalytic reactions under various metal oxides (ZnO, MgO, TiO2, and ZrO2) were evaluated qualitatively...
30 citations
TL;DR: In this article, CaO and HZSM-5 was developed to convert xylan and LDPE to valuable hydrocarbons by thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and elucidate the reaction mechanism.
Abstract: The high concentration of oxygenated compounds in pyrolytic products prohibits the conversion of hemicellulose to important biofuels and chemicals via fast pyrolysis. Herein CaO and HZSM-5 was developed to convert xylan and LDPE to valuable hydrocarbons by thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and elucidate the reaction mechanism were also investigated in detail. The results indicated that xylan/LDPE copyrolysis was more complicated than pyrolysis of the individual components. LDPE hindered the thermal decomposition and aromatic hydrocarbon formation from xylan at temperatures under 350 °C and had a synergistic effect at high temperatures. 50% LDPE was proven to be more beneficial than other percentages for the formation of monocyclic aromatic hydrocarbons. Simultaneously, the addition of CaO/HZSM-5 significantly reduced the reaction Ea and increased the reaction rate. CaO can effectively improve the deoxygenation and aromatization reaction, enhancing the yield and selectivity of aromatics to a certain extent. The maximum yield of hydrocarbons (96.01%), mono-aromatic hydrocarbons (88.53%) and SBTXE (85.79%) were obtained at a CaO/HZSM-5 ratio of 1:2, a pyrolysis temperature of 450 °C, a catalytic temperature of 550 °C, a catalyst dose of 1:2 and a xylan-to-LDPE ratio of 1:1 via an ex situ process. The system was dominated by toluene, xylene and alkyl benzene. Diels-Alder reactions of furans and hydrocarbon pool mechanism of nonfuranic compounds improved aromatic formation. This study provides a fundamental for recovering energy and chemicals from pyrolysis of hemicellulose.
27 citations
TL;DR: The stable radical cation of large aromatic hydrocarbons remains a challenge, due to the recessive aromatic character and high reactivity as mentioned in this paper, and the design, synthesis, and characterization of large-scale large aromatic polycyclic compounds is a challenge.
Abstract: The stable radical cation of large aromatic hydrocarbons remains a challenge, due to the recessive aromatic character and high reactivity. Here we report the design, synthesis, and characterization...
22 citations
TL;DR: In this paper, the influence of Ni to cerium ratio on hydrogen exchanged Zeolite Socony Mobil-5 (HZSM-5) catalysts was investigated for catalytic upgrading of pine derived oxygenated pyrolysis vapours into aromatic hydrocarbon and phenol.
21 citations
TL;DR: In this paper, the effect of NaOH on the preparation of aromatic hydrocarbons by catalytic pyrolysis of lignin/HZSM-5 was investigated.
21 citations
TL;DR: In this article, the authors employ GC-MS experiments and theoretical calculations to demonstrate that a hydrogen-pretreated Ga species and a reductive environment are critical for upgrading pine pyrolysis vapors into high yields of alkenes and aromatic hydrocarbons at near atmospheric pressure.
TL;DR: In this paper, a comparative study on the pyrolysis of C8-C10 linear alkylbenzenes including ethylbenzene, n-propyl-2-propenyl and n-butylbenzinene was performed with highly diluted mixtures in argon containing respectively the three fuels under nearly identical conditions in a single-pulse shock tube, at a nominal pressure of 20 bar and over a temperature range of 950-1700 K.
TL;DR: The 3D hollow graphitic carbon framework (HGCF) as discussed by the authors combines π-richelectron nanospaces with a high surface area and a hierarchical pore volume, both of which are particularly beneficial as porous electrodes for selective detection of hazardous aromatic hydrocarbon vapors over their aliphatic analogues.
TL;DR: Aromatic hydrocarbon pollution was gradually decreased along piedmont-alluvial plain-coast line, owing to a decrease in aquifer vulnerability, and was positively correlated with the size of the aquifer's particles.
TL;DR: In this paper, a dual-stage hydrotreating-cracking process is developed for more stable operation, where the cracking catalyst HZSM-5 was modified by MOx (M = Ga, Mo, and Zn).
TL;DR: In this article, a bio-oil hydrotreating-cracking process cofed with methanol was investigated, and the modification of cracking catalyst for enhanced aromatic hydrocarbon generation was investigated.
TL;DR: In this paper, a micro-pyrolyzer equipped with gas chromatography-mass spectrometry/flame ionization detector (MPy-GC/MS/FID) was used to evaluate the catalytic co-conversion of Kraft lignin (KL) and linear low-density polyethylene (LLDPE) over mesostructured catalysts.
17 Sep 2020
TL;DR: The benzene, toluene, and xylene (BTX) compounds currently utilized in many building materials and paints have been linked to deleterious health effects, and thus, monitoring the presence of these compounds has been monitored.
Abstract: The benzene, toluene, and xylene (BTX) compounds currently utilized in many building materials and paints have been linked to deleterious health effects, and thus, monitoring the presence of these ...
TL;DR: A series of new bowl-shaped N -hydroxyimide derivatives has been designed and used as selective organoradical catalysts that exhibit excellent site-selectivity in the amination of benzylic C(sp 3 )-H bonds in aromatic hydrocarbon substrates.
Abstract: A series of new bowl-shaped N-hydroxyimide derivatives has been designed and used as selective organoradical catalysts. A number of these bowl-shaped N-hydroxyimide derivatives exhibit excellent site-selectivity in the amination of benzylic C(sp3 )-H bonds in aromatic hydrocarbon substrates.
TL;DR: The Rhodotorula strain, which is likely a new undescribed species, was capable of removing singled ringed aromatic compounds, but could not remove benzo[a] pyrene nor phenanthrene, and the Exophiala strain showed a different removal capacity, which could remove the polyaromatic hydrocarbons but performed poorly at removing toluene and xylene.
Abstract: Since Aromatic hydrocarbons are recalcitrant and toxic, strategies to remove them are needed. The aim of this work was to isolate fungi capable of using aromatic hydrocarbons as carbon sources. Two isolates from an oil polluted site in Mexico were identified through morphological and molecular markers as a novel Rhodotorula sp. and an Exophiala sp. Both strains were able to grow in a wide range of pH media, from 4 to 12, showing their optimal growth at alkaline pH's and are both halotolerant. The Exophiala strain switched from hyphae to yeast morphotype in high salinity conditions. To the best of our knowledge, this is the first report of salt triggering dimorphism. The Rhodotorula strain, which is likely a new undescribed species, was capable of removing singled ringed aromatic compounds such as benzene, xylene, and toluene, but could not remove benzo[a] pyrene nor phenanthrene. Nevertheless, these hydrocarbons did not impair its growth. The Exophiala strain showed a different removal capacity. It could remove the polyaromatic hydrocarbons but performed poorly at removing toluene and xylene. Nevertheless, it still could grow well in the presence of the aromatic compounds. These strains could have a potential for aromatic compounds removal.
TL;DR: In this article, the effect of different hydrocarbon structures on viscosity reduction of long-chain viscoelastic surfactant (VES) solution was determined at various temperatures.
TL;DR: Gold-tube pyrolysis experiments were performed on two Athabasca oil sand bitumens at 300°C to 525°C with 2°C/h rate and 25°C step under 50MPa as mentioned in this paper.
01 Jan 2020-Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering
TL;DR: Predicting the structure of proteins and determining their in-silico interaction with array of pollutants enables us to predict the range of pollutants possible to be detected using these regulatory protein-based biosensors.
Abstract: On-line detection of aromatic hydrocarbon pollutants in aqueous environments can be achieved by biosensing strains having fusion of gene responsible for pollutant sensing protein with a rep...
TL;DR: In this paper, trimetallic unsupported MMoW catalysts were synthetized and tested in the liquid-phase biphenyl (BP) hydrogenation at 300°C and 5.5MPa of H2 pressure.
TL;DR: In this paper, 27 hydrocarbon source rocks from the Proteacidites asperopolus, Malvacipollis diversus and Lygistepollenites balmei biozones, Palaeogene Latrobe Group in the Gippsland Basin were analysed using gas chromatography-mass spectrometry.
TL;DR: The in-situ/ex-Situ reaction mode, catalyst/feedstock, and cellulose/SCG ratio were optimized to improve the aromatic hydrocarbon yield and formed more aromatic hydrocarbons from CCP.
TL;DR: The efficiency of the PCR incorporation of modified dUMPs modified with the most hydrophilic of the studied aromatic hydrocarbon substituents, a 4-hydroxyphenyl residue, was 60-85% of the efficiency of dTMP incorporation and the yield of the modified PCR product was significantly increased with increasing hydrophilicity of the aromatic hydro carbon substituent.
TL;DR: In this article, two spirocyclic aromatic hydrocarbon derivatives were prepared to clarify the molecular geometry effects on the regulation of the crystalline morphologies and photophysical behaviors of organic nanocrystals.
Abstract: Two spirocyclic aromatic hydrocarbon derivatives were prepared to clarify the molecular geometry effects on the regulation of the crystalline morphologies and photophysical behaviors of organic nanocrystals. Due to the different structural symmetry of a spiro-center, distinguishing nanocrystal morphologies with unique crystallization-enhanced/quenched emission was achieved.
TL;DR: The findings indicate that Pintsch gas tar has higher invasive and higher flux properties than most coal tars due to its relatively low density, low viscosity and, high content of water-soluble compounds.
TL;DR: Genes related to biodegradation of aromatic hydrocarbons, chemotaxis and flagella were identified from the genome, which will advance the fundamental understanding of the molecular mechanism for degradation and metabolizing of aromatic Hydrocarbons.
Abstract: Achromobacter xylosoxidans DN002 is capable of utilizing numerous aromatic hydrocarbons as sole carbon and energy resource. In this study, the whole genome of strain DN002 was sequenced and analyzed, which consisted of one circular chromosome of 5,943,204 bp and a 278,917 bp plasmid with an average GC content of 65.46 mol%, 5694 protein-coding genes, 13 rRNA genes and 57 tRNA genes. Analysis of cluster of orthologous group (COG) demonstrated that strain DN002 had remarkable gene abundance foramino acid transport and metabolism, transcription, inorganic ion transport and metabolism, energy production and conversion, and carbohydrate transport and metabolism. Genes related to biodegradation of aromatic hydrocarbons, chemotaxis and flagella were identified from the genome, which will advance our fundamental understanding the molecular mechanism for degradation and metabolizing of aromatic hydrocarbons.