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A >300°C distillation fraction (300F) from low-temperature coal tar was reacted with formaldehyde. Residual oil (RO) and residual solid (RS) were collected. RO was detected by gas chromatography-mass spectroscopy (GC-MS) and shows that it mainly contains alkanes and polycyclic aromatic hydrocarbons. The degradations under a nitrogen atmosphere of 300F and RO were investigated by Fourier transform infrared spectrometer. The result shows that 300F and RO consist of two degradation stages and five stages, respectively. CO has significant absorbency in the pyrolysis process of RO, not in 300DF. Modification of formaldehyde and compounds with carboxyl, short-chain fatty, and ester group in 300F generates polymers and fixes these compounds. [ABSTRACT FROM AUTHOR]

In this article, chlorosilane-modified ZSM-5 particles were incorporated into polydimethylsiloxane (PDMS) to form mixed matrix membranes (MMMs) for ethanol/water mixture separation via pervaporation (PV). The membranes were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and mechanical performance testing. The maximum loading and dispersion of ZSM-5 into PDMS were improved by chlorosilane modification. To evaluate the PV performance, the MMMs were used to separate an aqueous ethanol solution. The effect of zeolite loading and operational conditions on PV performance was investigated in detail. The separation factor of the composite membranes filled with modified ZSM-5 increased considerably versus unmodified membrane, while the total flux decreased to some degree. Of all the chlorosilane-modified membranes, dodecyltrichlorosilane modified ZSM-5 filled PDMS showed the best separation factor of 15.8 for ethanol. [ABSTRACT FROM AUTHOR]

The construction of three-dimensional hierarchical porous and hydrophobic-aerophilic interfaces facilitates mass transport and CO 2 enrichment by kinetically accelerating the CO 2 electrochemical reduction reaction (CO 2 RR). Inspired by the process of baking bread, in which pores that connect the interior of the bread to its exterior are created, we propose a template-free metal carbonate-porous metal oxide (MC-PMO) strategy to synthesize porous metal oxides with tunable pore size. Using this strategy, a series of porous metal oxides with different morphologies and different metals was successfully developed. Furthermore, the effect of catalyst mass transport on the CO 2 RR was explored. The porous catalysts with suitable pore size promoted mass transfer, which significantly enhanced the activation and transformation of CO 2. In addition, based on a hydrophobic group-modified metal oxide surface (HG-MO) strategy, a hydrophobic-aerophilic interface microenvironment was constructed to reduce the water dissociation activity and effectively inhibit the hydrogen evolution reaction (HER). HP-ZnO-500 @ 2-NTL was obtained by modifying hierarchical porous zinc oxide (HP-ZnO-500) with the hydrophobic 2-naphthalenethiol (2-NTL). The hydrophobic surface of HP-ZnO-500 @ 2-NTL was easily enriched with CO 2 gas under the influence of the "plastron effect", and the surface hydrophobic film stabilized the M–H bond. Thus, HER was suppressed. At − 1.0 V vs. RHE, HP-ZnO-500 @ 2-NTL achieved a faradaic efficiency of CO (FE CO) as high as 83.0%, and displayed high catalytic activity in a wide potential range. The "MC-PMO" strategy and "HG-MO" strategy reported herein are universal and are expected to guide the further preparation and modification of different metal-based porous metal oxides for sustainable CO 2 RR. [Display omitted] • Three-dimensional porous material synthesis strategy was developed. • Influence of mass transport capability of porous materials on CO 2 RR. • HER was inhibited in the hydrophobic-aerobic interface microenvironment. [ABSTRACT FROM AUTHOR]

Based on the three-link theory of the material balance, namely heat balance, momentum balance, and exergy balance, the reaction-regeneration system was calculated. Results showed that excessive fluidization air and burning dry gas would lead to high velocity, short residence time, low oxygen concentration and high partial pressure of steam in the coke-burning drum. Meanwhile, it would reduce catalyst activity, the burning heat and reutilization of exhaust-heat boiler, which caused the increasing of unit energy consumption. By decreasing the air flow, stopping burning the dry gas, reducing gasoline recycle ratio and increasing the ratio of catalyst to oil, the energy consumption can be reduced. The energy transforms efficiency was improved by reforming the waste heat boiler which could optimize the heat exchange, reduce the heat transfer exergy loss and so on. The energy-saving effect is obvious and the total energy consumption of devices reduced by about 31.04%. [ABSTRACT FROM AUTHOR]

The technology of coal pyrolysis and conversion of high value-added aromatic chemicals is one of the important ways of coal efficient and clean utilization. To obtain high yield aromatic compounds and tar from coal pyrolysis process with high yield, analyse the influencing factors including pyrolysis atmosphere, catalyst, solvent pretreatment technology as well as reactor type on pyrolysis product distribution. The results show that, the development of pyrolysis technology and catalyst help to improve the BTX yield, meanwhile some secondary causes also should be payed attention. [ABSTRACT FROM AUTHOR]

Incorporation of Ni active species with mesoporous carbon and the resulting composite materials have received much attention due to their nature of flexibility derived from a confluence of metallic and carbonic properties and numerous textural advantages inherited from mesoporous carbon substrates, contributing to their versatility in energy transformation. However, the efficient integration of such composite materials with complementary advantages in properties is still highly desired. Herein, confined growth of Ni(OH) 2 nanosheets within three dimensionally ordered mesoporous carbon (3DOMC) by steam-assisted crystallization is propose in this paper. High-crystalline Ni(OH) 2 species are found in two forms of confined extra-small nanosheets within the mesopores of 3DOMC and staggered nanosheets over the particles of 3DOMC, which can be reduced to the highly segregative Ni nanoparticles by sufficient reduction. By using as a catalyst for methane decomposition to produce CO x -free hydrogen, Ni/3DOMC contributes a maximum CH 4 conversion of 66.5% and H 2 output rate of 7.4 mmol. g cat −1·min−1 at 850 °C, more superior to the conventional Ni-incorporated active carbon (Ni/AC) catalyst. Moreover, the Ni/3DOMC catalyst also exhibits not only a higher initial reaction rate but also an improved catalytic stability attributed to the abundant homodispersed Ni active species by the highly hybrid structure. It is expected that the flexible component, well-defined structure, and superior CMD performance could promote a great application potential of Ni/3DOMC nanocomposites in catalysis. [Display omitted] • Efficient loading of Ni(OH) 2 nanosheets by using 3DOM carbon as a confined space provider. • High-crystalline Ni(OH) 2 with dual forms of confined extra-small nanosheets and staggered overgrown nanosheets. • Shorter unactivated period but higher initial reaction rate attributed to rapid mass transfer and well-dispersed Ni species. • NNi/3DOMC contributes a maximum CH 4 conversion of 66.5 % and a maximum H 2 output rate of 7.4 mmol.gcat-1•min-1 at 850 °C. [ABSTRACT FROM AUTHOR]

• CO 2 was hydrogenated to lower olefins and gasoline using EDTA-2Na-modified catalysts. • EDTA-2Na contributed to enhance the sintering resistance of catalysts. • EDTA-2Na modification is favorable for catalyst reduction. • Chemical adsorption of CO 2 is enhanced using EDTA-2Na-modified catalysts. • The catalysts prepared by this strategy are suitable for a low H 2 /CO 2 ratio. Capturing and utilization of carbon dioxide (CO 2) not only leads to effective use of carbon resources, but also alleviates environmental pollution caused by increasing concentration of CO 2 , thus making it a hot research topic in recent years. In this study, a series of highly dispersed iron-cobalt (Fe-Co) catalysts was prepared by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) modification, which could efficiently convert CO 2 into high value-added chemicals (C 2 -C 4 = and C 5 -C 11). X-ray diffraction (XRD) analysis showed that the addition of a small amount of Co and EDTA-2Na contributed to enhance the sintering resistance of Fe species. During the calcination process, EDTA4− can be decomposed into small organic molecules with reducibility, thus promoting the reduction of iron species. The CO temperature-programmed desorption (CO-TPD) results showed that cobalt enhanced the adsorption and activation of intermediate CO on Na x Fe-Co catalyst, thereby promoting the catalytic conversion of CO 2. The complexation of EDTA promotes the synergistic effect of Fe-Co bimetals, enhances the chemical adsorption of CO 2. Sodium in EDTA-2Na promotes the surface basicity of the catalysts, which is favored for improving the product distribution of hydrocarbons. At lower H 2 /CO 2 (1/1) ratio, the EDTA-2Na modified Fe-Co/Al 2 O 3 catalyst exhibited high conversion of CO 2 (32.8 %) and excellent selectivity toward high value-added chemicals. The selectivity of by-product CO was only 8.1 %; and C 2 -C 4 = (32.5 %) and C 5 -C 11 (46.3 %) accounted for ∼79 % selectivity among the hydrocarbons generated. [ABSTRACT FROM AUTHOR]

To investigate the effect of coordination features of Co(II)-glycine complex on the performance of Co/SiO2 for Fischer–Tropsch (FT) synthesis, Co(II)-glycine complex precursors were prepared by the conventional method, i.e., simply adding glycine to the solution of Co nitrate and novel route, i.e., reaction of glycine with cobalt hydroxide. The SiO2-supported Co catalysts were prepared by using the different Co(II)-glycine complexes. It is found that glycine is an effective chelating agent for improving the dispersion of Co and the mass-specific activity in FT synthesis when the molar ratio of glycine/Co2+ = 3, which is independent to the preparation method in this study. Significantly, the surface Co properties were significantly influenced by the coordination features of the Co2+ and the molar ratio of glycine to Co2+ in the Co(II)-glycine complex. Specifically, the Co(3gly)/SiO2 catalyst prepared by the novel route exhibits smaller and homogenous Co nanoparticles, which result in improved stability compared to Co-3gly/SiO2 prepared by the conventional method. Thus, the newly developed method is more controllable and promising for the synthesis of Co-based catalysts for FT synthesis. [ABSTRACT FROM AUTHOR]

Efficient activation and the conversion of methane to value‐added products have long attracted interest. Chemical looping reforming has become a competitive technology to transform methane into syngas that can act as raw material for various chemicals. In this paper, the methane chemical looping reforming reactivity of the Ce−Co composite oxygen carriers fabricated with different preparation methods, including solution combustion, ball‐milling, hydrothermal, and co‐precipitation method, are investigated on a fixed‐bed. Various bulk/surface characterizations (TEM, XRD, BET, XPS, Raman, etc.) were applied to reveal the effect of preparation methods on the properties of these oxygen carriers. The results indicate that the oxygen carrier prepared by the solution combustion method exhibits excellent methane conversion, high syngas yield, and desirable H2/CO ratio, as well as stable regenerability because of its relatively small crystal size, large specific surface area, high oxygen vacancy concentration and Ce3+/Ce4+ ratio. This work may be helpful in the preparation of highly active and stable oxygen carriers for chemical looping reforming reaction of methane. [ABSTRACT FROM AUTHOR]

It is very important to evaluate how coal tar asphaltenes (CTA) and corn cob (CB) could be used comprehensively in order to achieve zero waste. Catalytic co-pyrolysis is a feasible method to reduce CO 2 emissions, realizing the development and utilization of biomass energy, and the recycling of asphaltenes. In this study, the catalytic effect of K on co-pyrolysis was more obvious than that of Ca, Co, Ni, Cu and Zn based on the analysis of TG/DTG, FTIR and Py-GC/MS. The response surface design method and artificial neural network were introduced to comprehensively investigate the effects of mixing ratios, metal loads and heating rates on the catalytic co-pyrolysis. The results showed that K-catalysis co-pyrolysis effectively improved the yield of gas and char, and increased the content of phenolics. In particular, when the load of K was 5.3 wt%, the heating rate was 476 °C/min, and the proportion of CB was 38 wt%, the maximum solid yield was 35.16 wt%, and the solid product had good catalytic ability. Based on the above analysis, the mechanism of K-catalysis co-pyrolysis was proposed. Catalytic co-pyrolysis is a feasible method to reduce CO 2 emissions, realizing the development, utilization of biomass energy and the recycling of asphaltenes. In this study, the effects of K had more obvious catalytic effect than Ca, Co, Ni, Cu and Zn on the co-pyrolysis compared by TG/DTG, FTIR and Py-GC/MS. The response surface design method and artificial neural network were introduced to comprehensively investigate the effects of mixing ratios, metal loadings and heating rates on the catalytic co-pyrolysis. The results showed K-catalysis co-pyrolysis effectively improved the yield of gas and char, increased phenolic content, and the solid product had good catalytic ability. Based on the above analysis, the mechanism of K-catalyzed co-pyrolysis was proposed. [Display omitted] • Catalytic fast co-pyrolysis of corn cob and coal tar asphaltenes are investigated. • Metals, gas-liquid-solid products and influencing factors are analyzed. • K-catalysis increases phenols' content, and co-pyrolysis coke has catalytic ability. • Oxygenated compounds crack into small molecules such as ketones and aliphatics. • ANN model predicts product distribution by mixing ratio, heating rate and metal load. [ABSTRACT FROM AUTHOR]

• Gas-phase dehydrochlorination of 2‑chloro-3,3,3-trifluoropropene were investigated. • Catalytic performance of series of alkali halides were studied and compared. • HFY-2223tz was produced over CsF/AC-F catalyst with high yield and selectivity. • E1cB dehydrochlorination mechanism of HCFO-1233xf was revealed. • Catalyst deactivation resulting from F/Cl exchange reaction was revealed. 3,3,3-trifluoropropyne (HFY-2223tz) is a novel refrigerant with great physicochemical properties. Though preparation of HFY-2223tz from halogenated olefins is theoretically effective, it remains great challenges for dehydrohalogenation from halogenated olefins, limiting the detailed knowledge. Here, we established a facile investigation to explore the gas-phase dehydrochlorination reaction of 2‑chloro-3,3,3-trifluoropropene (HCFO-1233xf) over various halides (Na, K, Rb, Cs) supported active carbon (AC) catalysts. The CsF was concluded as the optimal active component with best dehydrochlorination selectivity and conversion of HCFO-1233xf. The CO 2 -TPD results illustrated that dehydrochlorination of HCFO-1233xf proceeded through E1cB mechanism. Mechanism study revealed the evolution of side-products including (Z / E)-1,3,3,3-tetrafluoropropylene, 2,3,3,3-tetrafluoropropylene, (Z / E)-1‑chloro‑3,3,3-trifluoroproene, and 3,3,3-trifluoroprop-1-ene, etc. However, observable deactivation of CsF catalyst was noticed, which, according to combined XRD and XPS results and density functional theory (DFT) calculations, was attributed to the F/Cl exchange between HCFO-1233xf and catalyst, leading to rapid fluorine consumption. This work thus provides basic knowledge about heterogeneous catalytic synthesis of HFY-2223tz from dehydrohalogenation of halogenated olefins. Synopsis: 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) can be highly selectively dehydrochlorinated over CsF/AC-F to generate 3,3,3-trifluoropropyne, however, the rapid deactivation of which resulting from the fluorine-chlorine exchange of HCFO-1233xf with CsF should be the most important issues need to be addressed in the future study. [Display omitted] [ABSTRACT FROM AUTHOR]