Oxygen-containing Organic Compounds Research Articles

Characterizing carbonaceous aerosols in residential coal combustion: Insights from thermal/spectral carbon analyzer coupled with photoionization mass spectrometry analysis

This study aims to identify unique signatures from residential coal combustion in China across various combustion conditions and coal types. Using a Thermal/Spectral Carbon Analyzer with a Photoionization Time-of-Flight Mass Spectrometer (TSCA-PI-TOF-MS), we focus on the optical properties and organic mass spectra of the emissions. Bituminous coal emerged as the primary emitter of total carbon, releasing 729 μg C/mg PM2.5 under smoldering and 894 μg C/mg PM2.5 under flaming. Carbon fractions mainly comprised OC1 and OC2, except for anthracite's dominance of EC1 under smoldering. Pyrolysis carbon absorption shifted from 405, 445 and 532 nm during smoldering to near-infrared bands (635–980 nm) during flaming for both bituminous and anthracite coal. Conversely, clean coal exhibited an inverse trend, attributed to additives enhancing oxygen-containing organic compounds and long-chain hydrocarbons released in charring process. Sample of bituminous coal began charring at OC3 step, while anthracite began earlier at OC2 step, particularly pronounced under flaming. Clean coal displayed unconventional charring at OC1 step under smoldering condition, producing signature compounds like butenal, methylfuran, furanylalcohol, and naphthol. The mass spectra of bituminous coal featured characteristic peaks, including m/z 192 (methylphenanthrene), 206, 220 (alkylated phenanthrenes), and 234 (retene). Anthracite coal showed a potential tracer at m/z 223, shifting from OC1 in smoldering to OC2 in flaming. Clean coal under flaming condition exhibited elevated levels of aromatic compounds, indicating potential toxicity, with peaks at m/z 178 (phenanthrene), 228 (chrysene/benz[a]anthracene), 234 (retene), 242 (methylchrysene), and 252 (benzo[a]pyrene, benzo[k]fluoranthene). Results also showed that the broader mass spectra range in the OC3 and OC4 steps across all coal types suggests that high-temperature pyrolysis promotes diversity. These findings contribute to refined source apportionment of carbon emissions from residential coal combustion and provide the scientific basis for the formulation of air pollution prevention strategies, crucial for coal-dependent regions.

Slow pyrolysis experimental investigation on the tar formation and its pyrolysis behavior characteristics

The problems of safety, environment and cost caused by biomass tar hinder the development of biomass-to-syngas technology. In this paper, the characteristics of biomass tar formation and pyrolysis behavior were studied by using a tubular furnace and a thermogravimetric analyzer. The activation energy and pyrolysis mechanism function of different pyrolysis tar samples were determined. Results indicated that phenols, furan-containing structures, ketones and other oxygen-containing organic compounds were the main components. The tar yield reached its maximum at 700 °C. Before 500 °C, the change of tar composition was mainly related to the decomposition of biomass structure. After 500 °C, the tar underwent homogeneous transformation, and after 700 °C, the secondary reaction of tar intensified. Among the three stages of tar pyrolysis, the first stage had the largest mass loss. And the pyrolysis mechanism functions followed by first stage of the two different tar were obviously different. 600 °C pyrolysis tar followed the Diffusion model, while 800 °C pyrolysis tar followed the Order of reaction model.

Solar oil refinery: Solar-driven hybrid chemical cracking of residual oil towards efficiently upgrading fuel and abundantly generating hydrogen

There is an urgent need to shift away from the present heavy dependence on fossil fuels and embrace renewable energy sources, particularly in the context of the energy-intensive oil refining process. Built on the Solar Reactive Utilization framework, this study presents an innovative concept called the Solar Oil Refinery, applying solar energy in the energy-demanding oil refining. Herein, a solar multi-energies-driven hybrid chemical oil refining system, exemplified by residual oil cracking, has been successfully developed and formulated in solar-driven thermo-electrochemical cracking of residual oil. This integrated solar oil refining system, coupled with solar pyrolysis and electrolysis - synergistic thermo- and electrochemistry, can greatly promote the “cracking” of residual oil. Owing to the simultaneous applications of solar heat, solar electricity, and the relevant chemical reactions, the system can significantly improve solar utilization efficiency, the cracking rate and the hydrogen yield. In the operation, solar energy, co-functioning with oil, is converted into light hydrocarbon fuel with the advantage of excess hydrogen energy storage. Notably, the temperature required for solar oil cracking is considerably reduced compared with that of conventional pyrolysis, with a cracking rate of 11.2% at the initial temperature of 230 ℃. As the temperature rises, the cracking rate is elevated, reaching 45.22% at 275 ℃ and an impressive 89.85% at the typical temperature of 425 ℃, in contrast to the 44.25% achieved in conventional pyrolysis. In the conventional pyrolysis, the gas, liquid, solid products and unreacted residual oil are accounted for 3.98%, 24.57%, 15.57%, and 55.75%, respectively, but, in the solar oil cracking, the gas, liquid, solid products and residual oil improve to 13.2%, 75.1%, 1.65%, and 10.05%, respectively. This process is characterized by a substantial increase of gas and liquid phase products, coupled with a significant reduction of solid phase products and unreacted residual oil. At 425 ℃, a noteworthy increase of 10.7% in gasoline, 21.7% in diesel, and 18.13% in vacuum gas oil occurs in solar oil cracking compared to conventional pyrolysis. The presence of light hydrocarbons and oxygen-containing organic compounds are detected in both gas-phase and liquid-phase products. In solar oil cracking, the hydrogen yield has been significantly boosted to 63.0% in the combined action of the hydrolysis and electrolysis, surpassing the hydrogen yield achieved through the conventional pyrolysis. The simultaneous utilization of both solar heat and solar electricity which substantially enhances total solar utilization efficiency and the oil conversion rate, can effectively reduce the consumption of the fossil energy in petroleum industry.

Catalytic ethanolysis of Hanglaiwan long flame coal to organic small-molecular compounds under mild conditions over SAPO-34-supported nickel nanoparticle catalyst

SAPO-34-supported nickel nanoparticle catalyst Ni/SAPO-34 was prepared by a modified deposition-precipitation method and nickel nanoparticles were uniformly dispersed onto the SAPO-34 crystal surface. Hanglaiwan long flame coal (HLFC) was subjected to the catalytic ethanolysis (CE) over Ni10%/SAPO-34 at 300 °C under 1 MPa of initial nitrogen pressure for 4 h to obtain more soluble organic small-molecule compounds (SOSMCs). Ni10%/SAPO-34 can effectively activate ethanol to release H+, +CH2CH3, and H-, and then precisely cleave >CH-O- and >Car-O- bridged bonds in HLFC. As a result, the total yield of soluble portion (SP) increases from 43.2 to 60.5 wt%. Arenes and oxygen-containing organic compounds are the main SOSMCs detected in SPCE from the CE and SPNCE from the ethanolysis, and the yields of arenes, hydroarenes, and phenols in SPCE are higher than those in SPNCE. In addition, compared to SPNCE, the condensation degree of aromatic rings in SPCE is higher. This investigation provides a promising alternative to the clean and value-added utilization of low-rank coals.

Investigation on the catalytic performance of magnetic copper ferrite nanoparticles in the catalytic hydroconversion of Hanglaiwan long flame coal

Magnetic copper ferrite (CuFe2O4) was prepared by hydrothermal synthesis method and used for the catalytic hydroconversion (CHC) of Hanglaiwan long flame coal (HLFC) in cyclohexane under 1 MPa of initial hydrogen pressure (IHP) at 300 °C for 4 h. The total yield of soluble portion (SP) from the CHC is 33.7 wt%, significantly being higher than that (10.5 wt%) from the non-CHC (NCHC) under the same conditions. The main compounds detected in SPCHC (for CHC) are arenes and oxygen-containing organic compounds (OCOCs). Benzyloxybenzene (BOB), 2-(benzyloxy)naphthalene (BON), oxybis(methylene)dibenzene (OBMDB), oxydibenzene (ODB), and 2,2′-oxydinaphthalene (ODN) were used as HLFC-related model compounds to investigate the catalytic activity of CuFe2O4 and understand the CHC mechanism of HLFC. According to the model reactions, CuFe2O4 activates H2 to biatomic active hydrogen (H…H) and splits H…H to mobile H+ and immobile H-. H+ addition to oxygen atoms (OAs) in >C-O- bridged bonds (BBs) cleaves the BBs and releases SP during the CHC of HLFC.

Release and evolution mechanism of oxygen-containing compounds and aromatics during the co-pyrolysis of waste tire and bamboo sawdust/rice husk by Py-GC/MS

Using the measurement technique pyrolysis gas-chromatography/mass spectrometry, the release characteristics of oxygen-containing compounds and aromatics during the pyrolysis of waste tire (WT) and the co-pyrolysis of WT and bamboo sawdust (BS)/rice hull (RH) were analyzed at low temperature (350 °C), medium temperature (550 °C) and high temperature (750 °C). The oxygen-containing compounds from the WT pyrolysis contained acids, phenols, alcohols, esters, peroxides and oxygen-containing heterocycles. Especially, the acids such as palmitic acid and stearic acid presented the highest proportion of 8.68% at 350 °C. The oxygen-containing compounds proportion showed a sharply decreasing trend with the increase of temperature. The aromatics proportion was extremely low at 350 °C and 550 °C, while aromatics proportion was as high as 44.64%, including benzene, alkyl substituted benzene, indene, naphthalene and alkyl substituted naphthalene at 750 °C. The proportion of benzene, toluene and xylene was 17.05%, and that of naphthalene and its derivatives was 7.86%. After adding BS or RH, the aromatics proportion increased at 550 °C. The aromatics proportion decreased by more than 16% with the addition of BS, while the aromatics proportion increased with the addition of RH, such as benzene, indene and naphthalene derivatives. It was also found that the relative oxygen-containing components and aromatics proportion showed an opposite trend along the temperature. At 750 °C, oxygen-containing compounds could be converted into aromatics through a series of free radical reactions. For the WT pyrolysis, N-containing organic compounds proportion in gas product as the temperature increased. While the S-containing organic compounds were released into gas phase only at 550 °C. Adding BS could reduce the formation of N- and S- containing organic compounds. However, adding RH inhabited the N-containing organic compounds formation only at 350 °C. Adding RH also inhabited the formation of S-containing organic compounds formation, while this while this positive effect was weaker than that of adding BS. Finally, according to the obtained results from Py-GC/MS at different temperatures, it was found that the active oxygen-containing free radicals released from BS could promote the chain breaking of rubber components and release hydrogen free radicals. With the aggravation of hydrogen transfer reaction, the oxygen-containing organic compounds were continuously transformed into hydrocarbon products. Co-pyrolysis promoted decarboxylation and decarbonylation reaction, resulting in the formation of H2 and free radicals, thus promoting the generation of alicyclic hydrocarbons, aliphatic chain hydrocarbons and benzene. This work provided the in-depth comparison and investigation the waste tire pyrolysis and products evolution.

Mesoporous zeolite Beta supported Ni nanoparticles for the catalytic hydroconversion of extraction portion from Jinjitan subbituminous coal to cycloalkanes

The catalytic hydroconversion (CHC) of heavy carbon organic species (HCOSs) to cycloalkanes represents an importantly used chemical industry process due to the wide applicability of the resulting products in energy and fine chemistry. Despite the existing conventional catalysts applied to the CHC of HCOSs, the development of highly active bifunctional Ni-based heterogeneous catalysts for this process is still a challenge. Therefore, we show that the modified deposition–precipitation of nickel (II) nitrate on hydrothermally synthesized mesoporous zeolite Beta (MZB) prepares a Ni/MZB catalyst with a through-crosslinking mesopore structure and uniformly disperse Ni nanoparticles (NPs) at rough MZB crystal surface. The 10%Ni/MZB (10% Ni loading), in the presence of exposing on amount of accessible Lewis acid sites (LASs) and attaching Ni NPs by chemical bonding from the silica matrix of MZB skeleton, exhibits excellent activity to promote the CHC of all kind of aromatic rings and heteroatom-containing species, including chain alkanes, arenes, oxygen-containing organic compounds (OCOCs), nitrogen-containing organic compounds (NCOCs), and sulfur-containing organic compounds (SCOCs), to produce cycloalkanes and hydroarenes under mild conditions. Interestingly, density functional theory (DFT) calculations indicate that the transfer of biatomic active hydrogen (H…H) and heterogenous H+ from 10%Ni/MZB plays important roles during the CHC of diphenoxybenzene (DPOB). After being recycled 4 times, 10%Ni/MZB is still maintains high activity for CHC of DPOB under mild conditions.

ETHOXYCARBONYLATION OF PENTENE-1 IN THE PRESENCE OF PdCl2(PPh3)2-PPh3-AlCl3SYSTEM

Reactions based on CO allow the synthesis of almost all oxygen-containing organic compounds, which are important raw materials for obtaining practically valuable products of wide consumption. Alkoxycarbonylation of olefins with CO and various alcohols in the presence of metal complex catalysts synthesizes esters of carboxylic acids in one step. The purpose:In accordance with previously synthesized ethyl esters of enanthic and 2-methylcapronic acids in the reaction of ethoxycarbonylation of hexene-1 with СОin the presence of the catalytic system PdCl2(PPh3)2-PPh3-AlCl3in this work we planned to synthesize ethyl esters of capronic and 2-methylvalerian acids by hydroethoxycarbonylation of pentene-1 with CO in the presence of the same catalytic system. Methodology: The autoclave was sealedand then filled with CO to 1.5 MPa pressure. The pressure of CO was brought to 2.0 MPa, the temperature was raised to 1000C for 1 hour and at this pressure and temperature the reaction mixture was stirred for 5 h. Results and discussion: Experimental results show that the reaction proceeds with the formation of two isomeric products of linear (EECA) and branched structure (EE-2-MVA). Optimal reaction conditions have been found, at which the yield of the target products (sum of isomeric esters of EECA and EE-2-MVA) reaches 74.72 %. Conclusion:The catalytic activity of the three-component system PdCl2(PPh3)2-PPh3-AlCl3 containing AlCl3as a promoter in the reaction of ethoxycarbonylation of pentene-1 has been established. The reaction proceeds with the formation of two isomeric products of linear (EECA) and branched structure (EE-2-MVA).

Catalytic hydroconversion of an organic waster oil to cyclanes over Ni/SiO2

An organic waster oil (OWO) was ultrasonically extracted with isometric acetone/carbon disulfide mixed solvent at room temperature to obtain extractable portion (EP) with the yield of 99.1%. Ni/SiO2 was prepared by a deposition–precipitation method. EP consist of arenes (34.1%), oxygen-containing organic compounds (OCOCs, 62.4%), and nitrogen-containing aromatics (NCAs, 3.5%) determined with a gas chromatograph/mass spectrometer (GC/MS). It was subjected to catalytic hydroconversion (CHC) over Ni/SiO2 in n-hexane under initial hydrogen pressure (IHP) of 4 MPa at 220 °C for different periods of time to obtain catalytically hydroconverted EPs (CHCEPs). All the organic species detected in EP were completely converted into cyclanes in CHCEP6 and the heat value increased from 28.52 to 37.04 MJ kg−1 by the CHC. In Ni/SiO2, highly dispersed nickel nanoparticles and mesoporous support with suitable acid sites play significant roles in hydrogenating aromatic rings and removing heteroatoms, respectively. To understand the mechanism for the CHC of EP, the catalytic activity of Ni/SiO2 was investigated using 4-cumylphenol (CP) and 1,3,5-triphenylbenzene (TPB) as the OWO-related model compounds. As a result, CP and TPB were completely converted over Ni/SiO2 in n-hexane at 220 °C or 200 °C under 4 MPa of IHP for 2 h, proving that Ni/SiO2 exhibits favorable CHC reactivity under mild conditions. Moreover, Ni/SiO2 has excellent cyclability after 4 runs and can be recovered by reduction with H2 at 500 °C for 4 h.

Complex mixture toxicology: Evaluation of toxicity to freshwater aquatic receptors from biodegradation metabolites in groundwater at a crude oil release site, recent analogous results from other authors, and implications for risk management

Aquatic toxicity posed by the complex mixture of biodegradation metabolites and related oxygen-containing organic compounds (OCOCs) in groundwater at typical petroleum release sites is of concern to regulatory agencies; several are using results from laboratory studies in older literature that are not appropriate analogs for risk management. Recent field studies from typical sites and natural groundwater should be utilized. In this study, OCOCs downgradient of the biodegrading crude oil release at the USGS Bemidji site were tested for freshwater aquatic toxicity using unaltered whole groundwater samples. This type of testing is optimal because the entire mixture of OCOCs present is tested directly and assessment is not affected by analytical limitations. Ceriodaphnia dubia and Pimephales promelas were tested for toxicity using USEPA Methods 1002 and 1000, which estimate chronic toxicity. OCOCs in representative samples up to the maximum concentration tested of 1710 ug/L Total Petroleum Hydrocarbons (TPH) (nC10 to nC40; without silica gel cleanup) did not result in effects relative to the lab control for C. dubia survival, or for P. promelas survival or growth; and did not result in effects above background for C. dubia reproduction. This is consistent with findings using the same testing methods and species on samples from 14 biodegrading fuel release sites: OCOCs did not cause increased toxicity relative to background at a maximum tested concentration of 1800 ug/L TPH (nC10 to nC28). Based on their toxicity testing using the same species and USEPA methods on groundwater from a biodegrading diesel release site, Washington Department of Ecology recently set a freshwater screening level for OCOCs at 3000 ug/L TPH (“Weathered DRO”). These studies indicate that, in the absence of dissolved hydrocarbons, OCOCs in groundwater from typical biodegrading fuel or crude oil releases are not toxic to C. dubia or P. promelas at typical concentrations.

The use of augmented reality in chemistry lessons in the study of “Oxygen-containing organic compounds” using the mobile application Blippar

A training kit has been created to study the topic of “Oxygen-containing organic compounds” using augmented reality. We chose the Blippar platform to work, it is quite simple and relatively free. The kit contains markers we have developed, on which, with the camera from the Blippar application, students will be able to observe thematic experiments and molecules of individual substances with the help of augmented reality. There was also a study on the effectiveness of our developments to implement augmented reality in the course of chemistry. The study results showed an increase in pupils’ motivation to study chemistry and their level of interest, facilitating the perception of the theoretical foundations of organic chemistry related to the spatial structure of molecules. Also, the use of augmented reality technologies creates the conditions for improving the level of digital and technological competencies of students, provides support for high quality teaching of chemistry in distance learning.

Comprehensive investigation of the mechanisms for pyrolyzing macromolecular networks in Hecaogou subbituminous coal by comparing the ethanolysis and flash pyrolysis

The organic macromolecular networks (MMNs) from Hecaogou subbituminous coal (HSBC) were investigated by multiple technical strategies, including SEM, 1H and 13C NMR, FTIR, XPS, TG/DTG, and flash pyrolysis (FP) technology. The pyrolysis mechanisms of MMNs were effectively investigated to release organic volatile species between ethanolyzed (E) inextractable portion (IEPE) and FP of IEP (IEPFP) at molecular level. In detail, solid-state 13C NMR analysis shows that carbon skeleton of IEP mainly consists of aliphatic (59.6%) and aromatic carbons (39.3%). XPS analysis shows that the >C–OH groups, pyrrolic, and sulfonic sulfurs in IEP surface are the most abundant O-, N-, and S-containing species. FTIR analysis proves that the weak- and medium >Cal-X (X denotes Cal<, H, O-, N<, and S-) in IEP could be cleaved during ethanolysis. Based on the destructive analysis with TG/DTG, the structure of MMNs in IEP features dissociating small molecular groups with different types >Cal-X bridge bonds, which facilitates the release of organic volatile species and then prevents the thermal condensation during pyrolysis process. Additionally, the relative content (RC) in IEPE of various organic species are as follows: chain alkanes (CAs, 18.5%), alkenes (0.9%), arenes (11.9%), and oxygen-containing organic compounds (OCOCs, 58.4%), while the RC of CAs (46.8%), alkenes (17.5%), arenes (16.8%), and OCOCs (13.8%) in IEPFP. Comprehensive investigation and detailed analysis the distribution of organic species further prove that the active hydrogen (H‧) cleave the >Cal-X of MMNs at different positions during the pyrolysis process to obtain more CAs, alkenes, alkanols, and phenols at molecular level.

Facile and continuous synthesis of graphene nanoflakes in RF thermal plasma

The aim of this work was to test the oxygen-containing organic compounds as prospective precursors of graphene flakes in a radiofrequency thermal plasma jet. The research covered the plasma processing of nine compounds, including alcohols, carboxylic acids, etc. Herein, the influence of the operating parameters, namely pressure, applied power, precursor feeding rate, and addition of hydrogen, on the efficiency of the product formation rate and yield was thoroughly studied. The morphology of the obtained materials was investigated by electron microscopy. The graphitization was evaluated via Raman spectroscopy. The thermal stability of products was studied utilizing thermogravimetry. Finally, the chemical composition was determined using X-ray photoelectron spectroscopy. Five compounds (ethanol, butyric acid, propionic acid, acetic anhydride, acetaldehyde) were found to be suitable precursors for continuous synthesis of graphene flakes, while ethyl acetate gave the mixture of graphene flakes and quasi-spherical byproduct. The plasma processing of methanol, formic acid, and acetic acid did not form any solid product.

Identification, distribution and geochemical significance of dinaphthofurans in coals

All six dinaphthofuran (DNF) isomers have been unequivocally identified in sedimentary organic matter through the co-injection with commercially available standards for the first time. The elution order and retention indices (I) of dinaphthofurans (DNFs) were obtained by GC–MS analysis. Quantum chemical computations were carried out to determine the thermodynamic stability sequence of DNF isomers, which is as follows: dinaphtho[1,2-b;2′,1′-d]furan > dinaphtho[1,2-b;1′,2′-d]furan > dinaphtho[1,2-b;2′,3′-d]furan > dinaphtho[2,1-b;2′,3′-d]furan > dinaphtho[2,3-b;2′,3′-d]furan > dinaphtho[2,1-b;1′,2′-d]furan. The DNF isomers are ubiquitous in coal samples in this study. The effects of maturity on the distribution patterns of DNFs in the coals were investigated and the relative abundance of dinaphtho[1,2-b;2′,1′-d]furan (1221DNF) to dinaphtho[1,2-b;2′,3′-d]furan (1223DNF) is significantly controlled by maturation. Based on theoretical calculations and geochemical data, a dinaphthofuran maturity indicator, defined as DNFR (1221DNF/1223DNF), is proposed. A preliminary calibration of DNFR against the vitrinite reflectance (%Ro) was established with the following relationship: %Rc = 1.27 × DNFR – 1.12 (for %Ro values > 1.00). DNFR is a useful indicator in evaluating the maturity for sediments with Type II–III organic matter. DNFs in coals may be produced during diagenesis and catagenesis and oxic environment contributes to their generation. This study helps us better understand the occurrence and significance of complex oxygen-containing organic compounds in sedimentary organic matter.

The Potential of Oxygenates to Increase the Risk of Exposure to Polycyclic Aromatic Hydrocarbons through Groundwater Contamination

The Clean Air Act (42 U.S. Code § 7401) is one of the United States of America’s most influential environmental laws. Under the Clean Air Act Amendments of 1990, oxygen-containing organic compounds must be added to some fossil fuels with the goal of combating CO2 and particulate emissions. However, one major implication is the effect of co-solvency on the leaching potentials of polycyclic aromatic hydrocarbons (PAHs) into groundwater. Our research investigated this effect on three groups of recalcitrant PAHs that are present in diesel fuel. Our results reveal that ethanol addition enhances the leaching potentials of these otherwise hydrophobic contaminants, with 10% ethanol (E10) resulting in elution of all the PAHs studied. While 5% ethanol addition to diesel fuel resulted in the elution of an average of 2.5% of all the trimethylnaphthalenes and 6.0% of the C2 alkylphenanthrenes present in diesel fuel, 10% ethanol addition led to the elution of more than 80% of each of the studied trimethylnaphthalene peaks and more than 70% of each of the studied C2 alkylphenanthrene peaks present in diesel fuel. In view of the known mutagenic and carcinogenic risks associated with exposure to PAHs through groundwater contamination, our study highlights the need for energy scientists to carefully consider the environmental and health implications of ethanol-blended innovations holistically. It is not enough to save the atmosphere but ruin the hydrosphere and most importantly, human health.

Selective catalytic hydroconversion of organic waster oil to cyclanes over a coal fly ash-derived zeolite-supported nickel catalyst: Waster to energy

An organic waster oil (OWO) from petroleum processing was extracted with petroleum ether (PE) to PE-extractable portion (PEEP) and extraction residue 1 (ER1), which was extracted with isometric acetone/carbon disulfide mixed solvent (MS) to MS-extractable portion (MSEP) and extraction residue 2 (ER2). A zeolite topology molecular sieve (ZTMS) was prepared from coal fly ash. Ni/ZTMS was prepared by loading Ni into ZTMS. Both PEEP and MSEP were subjected to catalytic hydroconversion (CHC) over Ni/ZTMS in n-hexane under 4 MPa of initial hydrogen pressure (IHP) at 240 °C for 2 h. The results show that most of arenes, hydroarenes, and oxygen-containing organic compounds (OCOCs) and all the nitrogen-containing aromatics (NCAs) in PEEP and all the arenes and NCAs together with most of OCOCs in MSEP were converted to cyclanes. To understand the mechanism for the CHC of PEEP and MSPE from the OWO, 2-phenylphenol (PP) was used as the OWO-related model compound. As a result, PP was completely converted and the yield of target product bicyclohexane (BCH) reached to 97.7% over Ni/ZTMS in n-hexane under 4 MPa of IHP at 240 °C for 2 h. The characterizations of Ni/ZTMS and time profiles of the products from the CHC of PP reveal that Ni/ZTMS can activate H2 to H⋯H and heterolytically cleave H2 to relatively mobile H+ and immobile H-; H⋯H addition to benzene ring in PP causes PP hydrogenation, while H+ addition to the oxygen in the resulting 2-phenylcyclohexanol (PCH) and 2-cyclohexylcyclohexanol (2-CHCH) induces the dehydroxylation of PCH and CHCH.

Catalytic hydroconversion of the light residue from Yinggemajianfeng lignite over a solid superacid

TFMSA/ATA was prepared by impregnating trifluoromethanesulfonic acid (TFMSA) onto the acid-treated attapulgite (ATA). Yinggemajianfeng lignite was extracted ultrasonically with a mixed solvent obtain the extract and extraction residue (ER), and then ER was separated by density difference to obtain the light residue (LR). The non-catalytic hydroconversion (NCHC) and TFMSA/ATA-catalyzed hydroconversion of LR were investigated in cyclohexane at 160 °C under 4 MPa of initial hydrogen pressure for 12 h. The soluble portions from NCHC (SPNCHC) and catalytic hydroconversion (SPCHC) were analyzed with a Fourier transform infrared spectrometer and gas chromatograph/mass spectrometer. As a result, the yield of SPCHC (60.0%) is significantly higher than that of SPNCHC (1.8%), suggesting that the thermal dissolution of LR at 160 °C is negligible and TFMSA/ATA significantly catalyzed the hydrocracking of LR to release SPCHC. Oxygen-containing organic compounds, especially 4-methylpent-3-en-2-one and 4-hydroxy-4-methylpentan-2-one, are predominant produced from the CHC of LR, suggesting that the cleavage of > Cα-Oβ- and > Cβ-Oα- bonds in LR significantly proceeded during the CHC of LR over TFMSA/ATA. Such a mechanism was proved by the CHC of oxybis(methylene)dibenzene.

THERMODESTRUCTION OF Lа(III) COORDINATION COMPOUNDS WITH ALIPHATIC β-KETO­ESTERS

Mono- and mixed-ligand complexes of La (III) with aliphatic β-ketoesters were synthesized in the solid state. The complexes have the general formulas LаL2OH·H2O (L=meacac, etacac, alacac) and La(meacac)2X·nCH3OH(X = NO3, CH3COO; n = 1, 2). Their composition, structure, and thermal properties were established by chemical and thermal analysis, IR spectroscopy. It is shown that β-ketoesters are coordinated to the La (III) ion bidentate-cyclically into monoligand hydroxocomp­lexes. Ligand complexes with methylacetoacetate have an oligomeric structure. They consist of cationic fragments [La(meacac)2]+ with bridged connection of the nitrate or acetate anions.&#x0D; The thermal destructions of LaL2OH·H2O (L = meacac, etacac, alacac), La(meacac)2NO3· 2CH3OH and La(meacac)2(CH3COO)·CH3OH were studied for the first time in the helium dynamic atmosphere by TGA-MS in the temperature range of 25–900 °C. Depending on the ligand, dehydratation of the hydroxo-complexes takes place in the 120–180 (meacac), 120–190 (etacac) or 110–160 °C (alacac) temperature range, and the mass loss corresponds with the detachment of one water molecule. Decomposition of mixed-ligand complexes starts with the detachment of methanol in the 60–100 °C range. For La(meacac)2NO3·2CH3OH the decomposition process is attended with oxidation of methanol to carbon dioxide due to reduction of the nitrate-ion to nitrogen dioxide. Further heating to 300–400 °C leads to destruction of organic parts of the complexes attended with the release of low-molecular oxygen-containing organic compounds (aldehydes, ketones, alcohols), carbon dioxide and water. At ~500 °C all the La(III) complexes under study totally decompose, yielding the oxycarbonate La2O2CO3, which was fixed by IR spectroscopy. Under further heating to 850 °С oxycarbonate gradually decomposes to La2O3 liberating CO2.

Deep hydroconversion of ethanol-soluble portion from the ethanolysis of Hecaogou subbituminous coal to ultra-clean liquid fuel over hierarchical porous zeolite Y supported Ni–Co nanoparticles

A hierarchical porous zeolite Y (HPZY) supported Ni–Co catalyst was prepared by pyrolyzing nickel tetracarbonyl and using modified deposition-precipitation to highly disperse Ni–Co nanoparticles onto HPZY. Hecaogou subbituminous coal was effectively ethanolyzed to obtain ethanol-soluble portion (ESPE) in a high yield (21.2%). Sequentially, ESPE was subjected to the deep hydroconversion (DHC) over prepared Ni10%-Co3%/HPZY at 150 °C under 4 MPa of initial hydrogen pressure for 24 h in n-heptane to produce deeply hydroconverted ethanol-soluble portion (ESPDHC). All the group components in ESPE, including arenes (53.3%), oxygen-containing organic compounds (24.4%), and nitrogen-containing aromatics (2.3%) were completely converted to chain alkanes (CAs, 36.8%), cyclanes (39.2%), and hydroarenes (24.0%). In addition, the hydroisomerization of CAs and hydroreforming of aromatic rings (ARs) in ESPDHC are predominant over Ni10%-Co3%/HPZY with more accessibility of active sites under mild conditions. Ni10%-Co3%/HPZY with suitable acidity and highly dispersed Ni–Co nanoparticles can effectively activate H2 to H⋯H and further heterogeneously split H⋯H to H+ and H−. H⋯H and H+ transfer plays crucial roles in the DHC of ESPE. Correspondingly, the related mechanisms are evidenced by the DHC of 2,2′-oxydinaphthalene (ODN) over Ni–Co/HPZY. Ni10%-Co3%/HPZY maintains high activity for the DHC of ODN under mild conditions after 4 recycles.

Molecular characterization of a middle/low-temperature coal tar by multiple mass spectrometries

A middle/low-temperature coal tar from Northern Shaanxi Province (M/LTCTNSP) was extracted with petroleum ether, and the resulting extract was analyzed by three mass spectrometers. The main group components detected by gas chromatograph/mass spectrometer (GC/MS) are aliphatics, arenes, oxygen-containing organic compounds (OCOCs), and nitrogen-containing organic compounds (NCOCs). In total, nearly 1000 aliphatics, arenes, OCOCs (mainly O1 and O2), NCOCs and sulfur-containing organnic compouds (SCOCs) were detected by the two-dimensional gas chromatography/time-of-flight mass spectrometer (GC×GC/TOF-MS). The relative abundances (RAs) of NCOCs, OCOCs, and SCOCs detected by ESI Orbitrap-mass spectrometry in the positive ion mode are 80.8%, 16.1%, and 3.1%, While in the negative ion mode, the RAs of OCOCs and NCOCs are 85.6%, and 14.4%, respectively. The condensation degree of aromatics and existing forms of heteroatoms were also examined.