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Gamma-alumina (γ-Al 2 O 3 ), one of the most common materials, is commercially used in many catalytic applications, including the active catalyst and support. However, the problem of fast deactivation makes the utilization of the γ-Al 2 O 3 challenging. This work elucidates the mechanism of coke formation consisting of coke deposition and evolution on γ-Al 2 O 3 (110) surfaces in differential conditions, including; clean and hydroxylation γ-Al 2 O 3 (110) in terms of partial and fully hydroxylation of OH/γ-Al 2 O 3 (110) and AlOOH(010), respectively. We demonstrated that the γ-Al 2 O 3 (110) surface is proper for atomic coke deposition and dimerization in the initial state, where the presence of OH species promotes the coke evolution to higher coke, C n (where n ≥ 3). Also, the higher coke formation thermodynamically preferred the cyclic form to the aliphatic one. The electron transfer from substrates to adsorbed coke illustrates the role of the electron donor of catalyst surfaces corresponding to the electron acceptor of adsorbed cokes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Coking is a substantial source of carbonaceous aerosols in China, but the emission characteristics and pollution levels of coking-produced organic carbon (OC) and elemental carbon (EC) remain unknown, causing considerable uncertainty in emission estimates. In this study, the emission factors of OC (EF OC ) and EC (EF EC ) of typical coking plants in Shanxi, China, were measured. The measured EF EC and EF OC from fugitive emissions (7.43 and 9.54 g/t) were significantly higher than those from flue gas (1.67 and 3.71 g/t). The technological conditions of coke production affect the emissions of OC and EC. For example, the total emissions from coke plants that use 3.2-m-high coke ovens were greater than those from plants that use 4.3- and 6-m-high ovens. The EF OC and EF EC for plants conducting stamp charging were considerably higher than those for plants using top charging. The stable carbon isotopes of total carbon (δ 13 C TC ), OC (δ 13 C OC ), and EC (δ 13 C EC ) for fly ash during coking were -23.74‰ to -24.17‰, -23.32‰ to -23.87‰, and -23.84‰ to -24.14‰, respectively, and no clear isotopic fractionation was found during coke production. Different EC/OC ratios from different emission pathways and the carbon isotope signature of coke production should be considered when investigating the sources of carbonaceous aerosols. The total estimated EC and OC emissions from coke production in China were 3.93 and 5.72 Gg in 2017, and Shanxi, Hebei, and Shaanxi made the largest contributions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Nickel catalysts are typically used for hydrogen production by reforming reactions. Reforming methane with carbon dioxide, called dry reforming of methane (DRM), is a good way to produce hydrogen or syngas (a mixture of hydrogen and carbon monoxide) from two notable greenhouse gases. However, Ni catalysts used for DRM suffer from severe coke deposition. It has been known that small Ni nanoparticles are advantageous to reduce coke formation, but the high reaction temperature of DRM (800 °C) inevitably induces aggregation of the nanoparticles, leading to severe coke formation and degraded activity. Here, we develop highly coke-resistant Ni catalysts by immobilizing premade Ni nanoparticles of 5.2 nm in size onto functionalized silica supports, and then coating the Ni/SiO2 catalyst with silica overlayers. The silica overlayers enable the transfer of reactants and products while preventing aggregation of the Ni nanoparticles. The silica-coated Ni catalysts operate stably for 170 h without any degradation in activity. No carbon deposition was observed by temperature programmed oxidation (TPO), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. The Ni catalysts without silica coating show severe sintering after DRM reaction, and the formation of filamentous carbon was observed. The coke-resistant Ni catalyst is potentially useful in various hydrocarbon transformations., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Various types of raw materials, including plant precursors, coal raw materials, solid fuel combustion residues, coal mining waste, coke fines, and others, are used for the production of porous carbon materials. One important type of porous carbon materials is microporous sorbents, which have a high volume of micropores. These pores provide carbon materials with the ability to effectively adsorb low-molecular-weight gases and possess molecular sieving properties, allowing their use in gas separation processes. The main method of increasing the porosity of sorbents and reducing pore sizes is the activation of sorbents at high temperatures using inert gases. This process increases the activity, capacity, and specific surface area of sorbents. The specific surface area of solid bodies plays a key role in their sorption properties at low and medium pressures. The use of activating agents, such as water vapor, in the thermal treatment processes of carbonaceous materials is a promising method for obtaining porous carbon materials. [ABSTRACT FROM AUTHOR]

A method is proposed for producing coke from distilled coal tar fractions. The influence of heat treatment of the tar fractions on the coke yield is investigated. The physicochemical characteristics of the coke produced from the tar fraction boiling above 280°C are investigated. [ABSTRACT FROM AUTHOR]

Given that coal may be oxidized and the yield of ammonia and hydrogen sulfide cannot be predicted from the volatile matters, mathematical formulas describing the yield of the basic coking products as a function of the elemental composition of the initial stamped coal batch are derived. It is found that, with increase in the content of gas coal (and hence in the volatile matter) in the stamped batch, the coke yield declines, but there is a higher yield of tar, benzene, carbon dioxide, pyrogenetic moisture, and coke-oven gas. The yield of the basic coking products is found to be additive. Hence, the total yield for the enterprise may be calculated, taking account of the characteristics and proportions of stamped and unstamped batch. [ABSTRACT FROM AUTHOR]

Potentially, the residues of solid municipal waste from the sorting station could be sent for disposal in coke batteries. A system is proposed for the preparation of such waste so as to permit its disposal in coke batteries. The maximum balance and composition of gas from waste pyrolysis are determined experimentally. The influence of the temperature and the heating rate of the product yield from waste pyrolysis is studied. The disposal of the residues of solid municipal waste in coke batteries is shown to be possible, after appropriate preparation of the waste. No change is expected in the yield and quality of coke and the coking byproducts. [ABSTRACT FROM AUTHOR]

The influence of the composition and preparation of the coal batch on the expansion pressure is a neglected aspect of coke production. A research coke oven is proposed for establishing the optimal composition of tamped and loose batch and determining the expansion pressure. This coke oven yields values of the expansion pressure for both loose batch and tamped batch. [ABSTRACT FROM AUTHOR]

The composition of distillates from shale resins produced by the semicoking of kukersite shale in a Kiviter gas generator is investigated by chromatography and mass spectrometry. It is enlightening to compare the coking products from the complete shale resins, light fuel-oil distillate, heavy fuel-oil distillate, and shale phenol fractions. The shale coke samples are investigated by electron microscopy and X-ray diffraction. [ABSTRACT FROM AUTHOR]

Analysis of the factors that significantly affect the moisture content of wet-quenched coke provides the basis for measures to stabilize the moisture content at all stages of the process: in the formulation, preparation, and coking of the coal batch and subsequent treatment of the coke. Those measures include the use of batch compositions, preparation techniques, and coking parameters such that uniformly conditioned coke with reasonable levels of porosity and specific surface is produced; uniform intake of coke in the charging car; sprayer configurations in the quenching tower such that the whole coke charge in the charging car is uniformly cooled; appropriate adjustment of the pumps, sprayers, and other equipment in the quenching tower; quenching by means of biochemically treated water without excessive organic pollutants; strict compliance with the quenching conditions (quenching time and residence time of the coke-filled car beneath the quenching tower); uniform distribution of the coke on the ramp; specified holding time of the coke on the ramp since shortening of that time is accompanied by exponential rise in moisture content; systematic identification of incompletely quenched coke on the ramp and its correction by manual quenching on the ramp and automatic quenching during coke transportation for sorting; and the use of air holes in the bunkers holding the blast-furnace coke so as to stabilize its moisture content. [ABSTRACT FROM AUTHOR]

Five different Colombian vacuum residues were thermally decomposed in a thermogravimetric analyzer. Three heating rates were employed to heat the sample up to 650°C. The kinetic analysis was performed by the Coats-Redfern method to describe the non-isothermal pyrolysis of the residua, a reaction model where the reaction order gradually increases from first to second order is proposed and an excellent agreement of the experimental with the calculated data is presented. The results also indicate that the pyrolysis of a vacuum residue cannot be modeled by a single reaction mechanism.

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ingeniería e Investigación is the property of Universidad Nacional de Colombia, Facultad de Ingenieraia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The characteristics of Kuznetsk Basin coal concentrates and their yield of coking products are determined. On that basis, experimental coal blends are formulated and analyzed. [ABSTRACT FROM AUTHOR]

In this work partial briquetting is employed as a means of biomass densification to allow for biomass inclusion in coking coal blends. The effect of increasing the bulk density was evaluated by comparison with direct addition. Two briquettes of different composition were studied. The influence of the briquettes on the Gieseler plasticity of the coals was determined. It was found that the effect of the binder was not enough to compensate for the decrease in plasticity produced by the inert components of the briquettes. Carbonizations were carried out in a movable wall oven of 17 kg capacity and the quality of the cokes produced was tested by evaluating their mechanical strength, coke reactivity to CO 2 and post-reaction strength. In addition, the porosity and ash chemistry of the cokes was determined and an attempt was made to establish a relation between these results and the quality of the cokes. Coke quality results suggest that 10–15 wt.% of briquettes containing biomass can be included in coking blends. [ABSTRACT FROM AUTHOR]

In the coking of pitch with different softening temperatures, coke particles of different type and structure are added. The coking temperature is 500 and 1200°C. The yield and quality of the pitch coke and compositions obtained are determined. In all cases, the introduction of coke particles is found to increase the yield and change the structure of the coke composition obtained. The microstructure of the composite coke may be regulated by introducing small coke particles of different structure in the high-temperature pitch prior to coking: particles of regular pitch coke increase the proportion of isotropic and finely fibrous structures; particles of acicular coke facilitate the appearance of fibrous and needle structures. [ABSTRACT FROM AUTHOR]

In order to expand the coking coal resources and reduce the cost of coal blending, taking the middle and high sulfur lean coal as the test sample, which is taken from No. 10 coal seam of western areas of Weibei coalfield in the southern of Erdos Basin. The middle and high sulfur lean coal contains low ash, its bond index and thickness of plastic layer is higher than that of generally lean coal, the inert and alive of petrography is close to 2, and the coking property is well. Through the coking test of middle and high sulfur lean coal, simulated coal blending of coal petrography, industrial coke oven coking test, verify the feasibility and determine the optimizations of middle and high sulfur lean coal blending coking. The results show that middle and high sulfur lean coal can be used in coal blending for coking, the blending content of middle and high sulfur lean coal should be controlled below 10%, and high content of strong caking index blending coal can enhance the thermal state index of coke. According to coal blending coking in industrial application of middle and high sulfur lean coal, show that using middle and high sulfur lean coal coking can produce quality qualified coke blending ratio of 3%~7%, expand coking coal resources and reduce the cost of blending coal using middle and high sulfur lean coal coking. [ABSTRACT FROM AUTHOR]

Copyright of Revista ION is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)