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Cage-typed sleeve control valve (CSCV) is the key basic equipment in direct coal liquefaction projects. The working condition of CSCV has the characteristics of high-pressure difference, high velocity, and high solid content. There is a general issue of liquid–solid two-phase erosion wear in CSCV, which can easily lead to the failure of the internal structure in the valve cage. Therefore, it is necessary to study erosion wear characteristics of internal structures in the valve cage. Considering the real conditions of erosion wear in the valve cage, a simplified T-shaped flow path is designed, and the precision of both the liquid–solid two-phase flow model and the erosion prediction model is validated. The flow characteristics and erosion wear characteristics in the T-shaped flow path under different working conditions are studied. Based on the simulation results of different structural parameters and boundary conditions, the erosion wear of the T-shaped flow path is predicted and calculated by the response surface method. Subsequently, the prediction formula for the maximum erosion rate is derived. The formula enables the swift determination of optimal structural parameters for the flow path, aiming to mitigate damage to the valve caused by erosion wear. This work can quickly predict the erosion wear rate of the key areas in the valve cage, which can provide a certain reference value for the life prediction and structural optimization of CSCV, and it can also benefit the safety and maintenance of the coal liquefaction system. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office 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.)

In order to study the effect of coal-based kerosene on physical and chemical properties of jet fuel, the coal-based kerosene has been added to jet fuel, and the more than 20 kinds of physical and chemical properties of jet fuel have been tested according to national standard«No.3 jet fuel» (GB 6537). The results show that the physical and chemical properties of jet fuel containing coal-based kerosene meet the requirements of national standard «No. 3 jet fuel» (GB 6537). When the volume content of coal-based kerosene increases, 11 kinds of properties of the jet fuel behave monotonic variation, 13 kinds of properties keep unchanged. It can be seen that jet fuel containing coal-based kerosene still meets the requirements of national standard «No. 3 jet fuel» (GB 6537), whereas the coal-based kerosene has different influence on properties of jet fuel. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office 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.)

In-situ catalytic generation of SiC coating on coal hydrogenation semi coke (SC, a new type of solid waste) was fabricated via the sol-gel coating, in-situ catalytic and subsequent high-temperature solid-phase reaction methods. The specific composition, microstructure, catalytic formation mechanism of SiC/C composite had been systematically investigated. The analysis results had proven that the loading Ni nanoparticles as catalyst favored the in-situ formation of SiC layer on SC, and significantly decreased the initial and complete reaction temperature of SiC. In particularly, the introduction of SiC had effectively improved the microwave absorption (MA) performances of composites. For the sample SiO 2 /SiC/C, its optimal reflection loss peak value (RL min = −20.4 dB) and effective absorption bandwidth (EAB max = 3.92 GHz) were achieved at the matched thickness of 2.0 mm. Whereas the RL min peak of −30.5 dB at the frequency of 4.06 GHz, and the EAB max of 3.68 GHz within the coating thickness of 2.0 mm had obtained for SiC/C samples. All results confirmed that the in-situ formation of SiC was beneficial for the regulation of impedance matching for the single carbon material, realizing the superior MA properties of SiC/C absorber. Furthermore, the successful fabrication of SiO 2 /SiC/C and SiC/C absorbers, in-situ ceramic phase loading low-cost carbon, provide the possibility for the large-scale application in the field of MA for SC, and expect to implement the environmental protection strategy of "waste in waste". [ABSTRACT FROM AUTHOR]

While RNA appears as a good candidate for the first autocatalytic systems preceding the emergence of modern life, the synthesis of RNA oligonucleotides without enzymes remains challenging. Because the uncatalyzed reaction is extremely slow, experimental studies bring limited and indirect information on the reaction mechanism, the nature of which remains debated. Here, we develop neural network potentials (NNPs) to study the phosphoester bond formation in water. While NNPs are becoming routinely applied to nonreactive systems or simple reactions, we demonstrate how they can systematically be trained to explore the reaction phase space for complex reactions involving several proton transfers and exchanges of heavy atoms. We then propagate at moderate computational cost hundreds of nanoseconds of a variety of enhanced sampling simulations with quantum accuracy in explicit solvent conditions. The thermodynamically preferred reaction pathway is a concerted, dissociative mechanism, with the transient formation of a metaphosphate transition state and direct participation of water solvent molecules that facilitate the exchange of protons through the nonbridging phosphate oxygens. Associative-dissociative pathways, characterized by a much tighter pentacoordinated phosphate, are higher in free energy. Our simulations also suggest that diprotonated phosphate, whose reactivity is never directly assessed in the experiments, is significantly less reactive than the monoprotonated species, suggesting that it is probably never the reactive species in normalpHconditions. These observations rationalize unexplained experimental results and the temperature dependence of the reaction rate, and they pave the way for the design of more efficient abiotic catalysts and activating groups. [ABSTRACT FROM AUTHOR]

A method for producing a liquid organic hydrogen carrier (LOHC) from coal tar is proposed. The carrier, a narrow fraction (T 10%/ T 90% = 199/224 °C) with a naphthenic content of ≈99.9 wt%, was obtained through deep hydrogenation of the corresponding fraction of coal tar recovered by vacuum distillation. As a result of hydrogenation, deep purification from sulfur compounds (<5 ppm) was achieved. The composition of the produced carrier was characterized in detail by GCxGC/MS to identify the main components. Further data processing allowed for the calculation of the theoretic hydrogen capacity (6.3 wt %) and hydrogen mass fraction (13.16 wt %). Dehydrogenation in a batch reactor produced a dehydrogenated form of the carrier with a dehydrogenation degree of about ≈82–85%. The main physical properties (density, boiling range, viscosity, and flash/freezing/pour points) were described. The resulting carrier was dehydrogenated in a flow reactor using a Pt/C catalyst, demonstrating stable operation for 108 h. Moreover, the LOHC derived from coal tar exhibited stability in its properties across three consecutive hydrogenation-dehydrogenation cycles conducted over a Pt/C catalyst at 360–370 °C. • A naphthene-rich fraction (CT-H 1) was obtained via hydrogenation of a coal tar cut and studied as a potential LOHC. • The hydrocarbon composition of CT-H 1 was studied in detail by GCxGC/MS. • The main properties of the H 2 -rich and H 2 -lean forms of the LOHC prototype were described. • Stable operation of a dehydrogenation flow reactor (Pt/C) was observed for 108 h. • The CT-H 1 LOHC prototype underwent 3 cycles of (de)hydrogenation with no significant loss of hydrogen yield. [ABSTRACT FROM AUTHOR]

The organic component of biomass pyrolysis oils is composed of a light fraction (C2–C4 volatiles, sugar- and lignin-derived monomers) and a less polar heavy fraction (pyrolytic lignin/humins, greater than approximately 200 g/mol). Importantly, this heavy fraction can account for roughly one-third to one-half of the total pyrolysis oil. While the composition and characteristics of the light fraction are generally well understood, research is still needed for the characterization of the heavy fraction. Some important thermodynamic fuel properties of this fraction are the heat of combustion, normal boiling point, heat of vaporization, and flash point, which are (computationally) estimated in this work with regularized regression and empirical correlations. The quantification of these properties has implications on downstream utilization, particularly in the context of co-processing bio-oils with plastic and coal liquefaction products and/or crude petroleum. Finally, challenges and opportunities for (experimental) work are discussed for the advancement of sustainable valorization of biomass pyrolysis oils. [ABSTRACT FROM AUTHOR]

Rates of microbial processes are fundamental to understanding the significance of microbial impacts on environmental chemical cycling. However, it is often difficult to quantify rates or to link processes to specific taxa or individual cells, especially in environments where there are few cultured representatives with known physiology. Here, we describe the use of the redox-enzyme-sensitive molecular probe RedoxSensor™ Green to measure rates of anaerobic electron transfer physiology (i.e., sulfate reduction and methanogenesis) in individual cells and link those measurements to genomic sequencing of the same single cells. We used this method to investigate microbial activity in hot, anoxic, low-biomass (~10³ cells mL-1) groundwater of the Death Valley Regional Flow System, California. Combining this method with electron donor amendment experiments and metatranscriptomics confirmed that the abundant spore formers including Candidatus Desulforudis audaxviator were actively reducing sulfate in this environment, most likely with acetate and hydrogen as electron donors. Using this approach, we measured environmental sulfate reduction rates at 0.14 to 26.9 fmol cell-1 h-1. Scaled to volume, this equates to a bulk environmental rate of ~103 pmol sulfate L-1 d-1, similar to potential rates determined with radiotracer methods. Despite methane in the system, there was no evidence for active microbial methanogenesis at the time of sampling. Overall, this method is a powerful tool for estimating species-resolved, single-cell rates of anaerobic metabolism in low-biomass environments while simultaneously linking genomes to phenomes at the single-cell level. We reveal active elemental cycling conducted by several species, with a large portion attributable to Ca. Desulforudis audaxviator. [ABSTRACT FROM AUTHOR]

The cyclic hydrogenation technology in a direct coal liquefaction process relies on the dissolved hydrogen of the solvent or oil participating in the hydrogenation reaction. Thus, a theoretical basis for process optimization and reactor design can be established by analyzing the solubility of hydrogen in liquefaction solvents. Experimental studies of hydrogen solubility in liquefaction solvents are challenging due to harsh reaction conditions and complex solvent compositions. In this study, the composition and content of liquefied solvents were analyzed. As model compounds, hexadecane, toluene, naphthalene, tetrahydronaphthalene, and phenanthrene were chosen to represent the liquefied solvents in chain alkanes and monocyclic, bicyclic, and tricyclic aromatic hydrocarbons. The solubility of hydrogen X (mol/mol) in pure solvent components and mixed solvents (alkanes and aromatics mixed in proportion to the chain alkanes + bicyclic aromatic hydrocarbons, bicyclic saturated aromatic hydrocarbons + bicyclic aromatic hydrocarbons, and bicyclic aromatic hydrocarbons + compounds containing heteroatoms composed of mixed components) are determined using Aspen simulation at temperature and pressure conditions of 373–523 K and 2–10 MPa. The results demonstrated that at high temperatures and pressures, the solubility of hydrogen in the solvent increases with the increase in temperature and pressure, with the pressure having a greater impact. Furthermore, the results revealed that hydrogen is more soluble in straight-chain alkanes than in other solvents, and the solubility of eicosanoids reaches a maximum of 0.296. The hydrogen solubility in aromatic ring compounds decreased gradually with an increase in the aromatic ring number. The influence of chain alkanes on the solubility of hydrogen predominates in a mixture of solvents with different mixing ratios of chain alkanes and aromatic hydrocarbons. The solubility of hydrogen in mixed aromatic solvents is less than that in the corresponding single solvents. Hydrogen is less soluble in solvent compounds containing heteroatoms than in compounds without heteroatoms. [ABSTRACT FROM AUTHOR]

Autotrophic theories for the origin of metabolism posit that the first cells satisfied their carbon needs from CO2 and were chemolithoautotrophs that obtained their energy and electrons from H2. The acetyl-CoA pathway of CO2 fixation is central to that view because of its antiquity: Among known CO2 fixing pathways it is the only one that is i) exergonic, ii) occurs in both bacteria and archaea, and iii) can be functionally replaced in full by single transition metal catalysts in vitro. In order to operate in cells at a pH close to 7, however, the acetyl-CoA pathway requires complex multi-enzyme systems capable of flavin-based electron bifurcation that reduce low potential ferredoxin--the physiological donor of electrons in the acetyl-CoA pathway--with electrons from H2. How can the acetyl-CoA pathway be primordial if it requires flavin-based electron bifurcation? Here, we show that native iron (Fe0), but not ni0, Co0, Mo0, NiFe, Ni2Fe, Ni3Fe, or Fe3O4, promotes the H2-dependent reduction of aqueous Clostridium pasteurianum ferredoxin at pH 8.5 or higher within a few hours at 40 °C, providing the physiological function of flavin-based electron bifurcation, but without the help of enzymes or organic redox cofactors. H2-dependent ferredoxin reduction by iron ties primordial ferredoxin reduction and early metabolic evolution to a chemical process in the Earth's crust promoted by solid-state iron, a metal that is still deposited in serpentinizing hydrothermal vents today. [ABSTRACT FROM AUTHOR]

Coal liquefaction and heavy oil processing have become the urgent need for national energy strategic technology reserves in China. However, the inactivation of solid catalysts in these processes is an inevitable problem. Therefore, a self-catalysed method was proposed. The properties of raw oil could be changed by adding a modifier, as it has the function of self-catalysis, and the additional catalyst is no longer needed. The effect of 200 ppm modifier on the hydrogenation of heavy oil and 500 ppm on the hydrogenation of coal and oil were investigated. The results showed that modifiers could be miscible with heavy oil at 50~100 °C and could change the properties of oil. When the temperature exceeded 250 °C, the sulfur element in the heavy oil combined with the metal element brought in by the modifier to form a particle with the size of 2–8 nm, which could interact with the hydrogen molecule to activate the hydrogen molecule. Activated hydrogen atoms further formed the complexes with nickel, vanadium, calcium, iron, and other elements in heavy oil to achieve the purpose of purifying and lightening the oil phase. Therefore, the self-catalysed method could be widely used in oil refining and would greatly promote the development of the oil refining and catalysis industry.

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.)

High-valent iron-oxo species (FeIV=O) has been a long-sought-after oxygen transfer reagent in biological and catalytic chemistry but suffers from a giant challenge in its gentle and selective synthesis. Herein, we propose a new strategy to synthesize surface FeIV=O (=FeIV=O) on nanoscale zero-valent iron (nZVI) using chlorite (ClO2 -) as the oxidant, which possesses an impressive =FeIV=O selectivity of 99%. =FeIV=O can be energetically formed from the ferrous (FeII) sites on nZVI through heterolytic Cl-O bond dissociation of ClO2 - via a synergistic effect between electron-donating surface =FeII and proximal electron-withdrawing H2O, where H2O serves as a hydrogen-bond donor to the terminal O atom of the adsorbed ClO2 - thereby prompting the polarization and cleavage of Cl-O bond for the oxidation of =FeII toward the final formation of =FeIV=O. With methyl phenyl sulfoxide (PMS16O) as the probe molecule, the isotopic labeling experiment manifests an exclusive 18O transfer from Cl18O2 - to PMS16O18O mediated by =FeIV=18O. We then showcase the versatility of =FeIV=O as the oxygen transfer reagent in activating the C-H bond of methane for methanol production and facilitating selective triphenylphosphine oxide synthesis with triphenylphosphine. We believe that this new =FeIV=O synthesis strategy possesses great potential to drive oxygen transfer for efficient high-value-added chemical synthesis. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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 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.)

Liquefaction of low-rank coal has been done to optimize the utilization of low-rank coal, which is less economical for obtaining alternative fuel oil. Coal samples were taken from the Bukit Pinang coal mine, Samarinda Ulu, East Kalimantan. Coal was liquefied using the NEDOL procedure at PUSPITEK, Serpong, South Tangerang, Indonesia. This Bukit Pinang coal liquefaction produces five fractions consisting of Naphta, Light Oil (LO), Middle Oil (MO), Heavy Oil (HO), and Coal Liquid Bottom (CLB) fractions. The liquefaction yield was dominated by the HO and CLB fractions (> 50% by weight). The naphtha, MO and LO fractions were fractionated using SiO2 GF254 Thin Layer Chromatography (TLC) plate. It produced aliphatic and aromatic hydrocarbon fractions. Aliphatic hydrocarbon fractions were analyzed using a Gas Chromatography-Mass Spectrometer (GC-MS), while the aromatic hydrocarbon fractions were not analyzed. Mass spectrum studies showed that the components consisted of n-alkanes, isoalkanes (branched alkanes), cycloalkanes and alkyl cycloalkanes. The aliphatic hydrocarbon components resulting from the liquefaction of low-rank coal showed its equivalence with the components that make up fuel oil. Therefore, this coal liquefaction can be suggested as an optimization for low-rank coal, which is less economical.

Maritime and maritime transport is a vital component of the global economy and transport network. The number of people, firms and organizations using shipping is growing worldwide. As with other transport systems, safety is critical in maritime transport. Because ship emergency processes are very different from emergency evacuation processes from buildings and other vehicles and are more complex, many researchers have published a wide range of documents relevant to this specific area of research. In recent decades, marine accidents have attracted a lot of attention due to huge material damage, accidents and serious environmental pollution. Maritime transport can include unforeseen events resulting in catastrophic casualties as well as fatal injuries at sea. About 63% of shipping accidents in the world are recurring. In other words, they arise with courts that have already survived at least one previous accident. In this case, emergency management plans are recognized as a priority for prompt consideration, taking into account the potential consequences of natural disasters in the marine industry. The article discusses the issues of coal transportation by sea and requirements regarding the safe laying and transportation of coal. Unsafe transportation can lead to appropriate risks on board, such as structural damage iz-za improper distribution of coal, chemical reaction leading to spontaneous combustion, release of explosive gases and liquefaction. Since coal is subject to liquefaction, a number of precautions and procedures without precautions and follow procedures for safe loading and transportation. Purpose. The goal is to analyze coal as a dangerous cargo, and the risks associated with its transportation. Methodology the article used statistical methods of analysis and factor method of coal liquefaction. Results: parameters of comparison of coal particles, for its safe transportation. Practical implications it is advisable to apply the obtained results when transporting general goods by sea.

Porous carbon nanofibers are commonly used for adsorption processes owing to their high specific surface area and rich pore structure. However, the poor mechanical properties of polyacrylonitrile (PAN)-based porous carbon nanofibers have limited their applications. Herein, we introduced solid waste-derived oxidized coal liquefaction residue (OCLR) into PAN-based nanofibers to obtain activated reinforced porous carbon nanofibers (ARCNF) with enhanced mechanical properties and regeneration for efficient adsorption of organic dyes in wastewater. This study examined the effects of contact time, concentration, temperature, pH, and salinity on the adsorption capacity. The adsorption processes of the dyes in ARCNF are appropriately described by the pseudo-second-order kinetic model. The maximum adsorption capacity for malachite green (MG) on ARCNF is 2712.84 mg g−1 according to the fitted parameters of the Langmuir model. Adsorption thermodynamics indicated that the adsorptions of the five dyes are spontaneous and endothermic processes. In addition, ARCNF have good regenerative performance, and the adsorption capacity of MG is still higher than 76% after 5 adsorption-desorption cycles. Our prepared ARCNF can efficiently adsorb organic dyes in wastewater, reducing the pollution to the environment and providing a new idea for solid waste recycling and water treatment. [ABSTRACT FROM AUTHOR]

Methanol, which produced in large quantities from low-quality coal and the hydrogenation of CO2, is a potentially renewable one-carbon (C1) feedstock for biomanufacturing. The methylotrophic yeast Pichia pastoris is an ideal host for methanol biotransformation given its natural capacity as a methanol assimilation system. However, the utilization efficiency of methanol for biochemical production is limited by the toxicity of formaldehyde. Therefore, reducing the toxicity of formaldehyde to cells remains a challenge to the engineering design of a methanol metabolism. Based on genome-scale metabolic models (GSMM) calculations, we speculated that reducing alcohol oxidase (AOX) activity would re-construct the carbon metabolic flow and promote balance between the assimilation and dissimilation of formaldehyde metabolism processes, thereby increasing the biomass formation of P. pastoris. According to experimental verification, we proved that the accumulation of intracellular formaldehyde can be decreased by reducing AOX activity. The reduced formaldehyde formation upregulated methanol dissimilation and assimilation and the central carbon metabolism, which provided more energy for the cells to grow, ultimately leading to an increased conversion of methanol to biomass, as evidenced by phenotypic and transcriptome analysis. Significantly, the methanol conversion rate of AOX-attenuated strain PC110-AOX1-464 reached 0.364 g DCW/g, representing a 14% increase compared to the control strain PC110. In addition, we also proved that adding a co-substrate of sodium citrate could further improve the conversion of methanol to biomass in the AOX-attenuated strain. It was found that the methanol conversion rate of the PC110-AOX1-464 strain with the addition of 6 g/L sodium citrate reached 0.442 g DCW/g, representing 20% and 39% increases compared to AOX-attenuated strain PC110-AOX1-464 and control strain PC110 without sodium citrate addition, respectively. The study described here provides insight into the molecular mechanism of efficient methanol utilization by regulating AOX. Reducing AOX activity and adding sodium citrate as a co-substrate are potential engineering strategies to regulate the production of chemicals from methanol in P. pastoris. [ABSTRACT FROM AUTHOR]

Objective The second-generation biodiesel is produced through technological transformation of idle hydrogenation units to increase the application proportion of green, low-carbon and clean fuels, and practice the national strategy of carbon peaking and carbon neutralization. Methods According to the current situation of the existing idle 0.3 Mt/a coal tar hydrogenation unit in a petrochemical company, the original key equipment and high-pressure equipment are maintained as much as possible to avoid problems such as long-term manufacturing and procurement of equipment. After comprehensive consideration of multiple factors, it was decided to transform reactor 1 into expanded-bed reactor, reactor 2 was still a fixed-bed reactor, and the reactor internals and process flow were adaptively transformed. After the transformation of the unit, the process flow was the combined process flow of expanded-bed/fixed-bed hydrogenation. Results After the implementation of the transformation, the unit produced qualified second-generation biodiesel, the temperature rise of the expanded-bed reactor was gentle, the pressure drop in the reactor bed was stable, which effectively protected the fixed-bed reactor, reduced the severity of the unit operation and prolonged the unit operation cycle. Conclusions The second-generation biodiesel produced by transforming the idle fixed-bed hydrogenation unit into the expanded-bed/fixed-bed hydrogenation combined process meets the requirements of product standards. The unit transformation has the advantages of small quantities, short transformation cycle, less investment and quick effect. It has good industrial promotion value for the transformation of similar units at home and abroad. [ABSTRACT FROM AUTHOR]

The occurrence of sulfur in coal direct liquefaction residue affects its further high quality and high value utilization. Electrochemical desulfurization is characterized by mild reaction conditions, simple operation, easy separation of sulfur conversion products and little influence on the properties of the liquefied residue. An anodic electrolytic oxidation desulphurization experiment was carried out on the liquefaction residue of the by-product of a coal-to-liquid enterprise in the slurry state. An electrochemical test and material characterization of raw materials before and after electrolysis showed that electrolytic oxidation can desulfurize the liquefaction residue under an alkaline condition. Linear sweep voltammetry (LSV) was used for the electrolysis experiments to obtain the optimal slurry concentration of 60 g/L. On this basis, the reaction kinetics were calculated, and the minimum activation energy in the interval at 0.9 (V vs. Hg/HgO) was 19.71 kJ/mol. The relationship between the electrolytic desulfurization of the liquefied residue and energy consumption was studied by the potentiostatic method. The influence of anodic potential and electrolytic temperature on the current density, cell voltage, desulfurization rate and energy consumption was investigated. The experimental results showed that the desulfurization rate and total energy consumption increase positively with the increase in reaction temperature and electrolytic potential in a certain range. The influence of the reaction temperature on the desulfurization rate and total energy consumption is more prominent than that of electrolytic potential, but the energy consumption of sulfur removal per unit mass does not show a positive correlation. Therefore, with the energy consumption per unit mass of sulfur removal as the efficiency index, the optimal experimental results were obtained: under the conditions of 0.8 (V vs. Hg/HgO) anode potential, 50 °C electrolytic temperature, 60 g/L slurry concentration and 14,400 s electrolytic time, the desulfurization rate was 18.85%, and the power consumption per unit mass of sulfur removal was 5585.74 W·s/g. The results of XPS, SEM, BET and IC showed that both inorganic and organic sulfur were removed by electrolytic oxidation, and the morphology, pore structure and chemical bond of the liquefied residue were affected by electrolytic oxidation. The research method provides a new idea and reference for the efficiency evaluation of desulfurization and hydrogen production from coal liquefaction residue. [ABSTRACT FROM AUTHOR]

• The impact of ageing on carbon emissions in the whole economic system is explored. • Household consumption pattern of different age groups is depicted in detail. • The change of population age structure had led to a decline in carbon emissions. • The impact of ageing on carbon emissions had obvious regional heterogeneity. Ageing can have a considerable ripple effect on carbon emission by affecting production and consumption of economic system. Based on an input-output structural decomposition analysis, this study analyses the impact of ageing on urban residents' carbon emissions in China from 2002 to 2007 and 2007 to 2012, and explores the regional heterogeneity and temporal uncertainty of the impact. At the national level, older adults slowed the growth of direct carbon emissions in both periods, because their per capita energy consumption fell more in the first period, then switched from coal to gas and electricity consumption. They contributed less to the growth of indirect carbon emissions in both periods due to the minimum increase in their per capita consumption among all age groups. Moreover, the impact of ageing on carbon emissions had clear regional heterogeneity. This study is beneficial to provide suggestions regarding carbon emission reduction and adapting to demographic changes. Ageing; Household consumption; Carbon emissions; Input-output; Structural decomposition analysis. [ABSTRACT FROM AUTHOR]

Coal chemical industry is a pathway for cleaner and more efficient consumption of coal. The modern coal chemical industry in China also acts as a national strategic technology reserve. However, high water demand by this industry and the high volume of outflow, often containing high levels of recalcitrant organic and inorganic pollutants, are some of the major environmental issues that need to be addressed. The implementation of new water treatment systems and the retrofit of existing water treatment facilities are of interest to both academia and the industry. This review selected coal gasification, coal liquefaction， and coking as three of the representative techniques, and briefly introduced the background, conversion processes， and then pinpointed the main wastewater discharge steps and the basic characteristics of the wastewater. At last， the review compiled representative research studies that apply electrochemical techniques in treating wastewater from the coal chemical industry and summarized the treatment mechanisms and performances. Recommendations for future study are provided accordingly. [ABSTRACT FROM AUTHOR]

ABSTRACT. A method for direct liquefaction of coal is presented. After separating the coal from waste rock gravitationally in an aqueous salt solution, drying and grinding, the purified separated coal is mixed with a paste-forming reagent. The paste is ground until a colloidal particle size and hydrogenated for 2 hours at temperature of 405°C and 11 MPa hydrogen pressure. Artificial oil was obtained with over 95 % yield with respect to the initial amount of purified coal when the contact of excavated coal with air was avoided. Based on findings, a technology is proposed for underground coal liquefaction with significantly reduced energy consumption of the process, removed environmental hazards and higher efficiency with respect to existing technologies.

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Development of inexpensive and environmentally friendly chemical sensors can help improve the global ecological environment and reduce pollutant emissions. In this work, asphaltene of coal liquefaction by-product was employed as the carbon source to fabricate carbon dots (CDs) by straightforward microwave radiation. The asphaltene-based CDs gave out blue emission under UV light excitation. Interestingly, the CDs are highly lipophilic because of its carbonized structure and insufficient hydrophilic groups. Based on these findings, an outstanding fluorescent sensor for 2,4,6-trinitrophenol (TNP) was developed by loading asphaltene-based CDs into polymeric micelles. The micelle formed by nonionic tri-block copolymers exhibited a hydrophobic inner cavity and hydrophilic surface. Due to the protection of the micelles, the emission of asphaltene-based CDs was enhanced by 2.89 times. But the fluorescence was significantly quenched by TNP through energy transfer and electron transfer mechanism, showing high sensitivity to TNP with a detection limit of 0.21 μM. The findings presented here provide a green method to synthesize fluorescent CDs and a promising strategy to design fluorescent probes. [ABSTRACT FROM AUTHOR]

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.)

This paper introduces the application background of plate-fin heat exchanger and summarizes the research process of plate-fin heat exchanger at domestic and abroad. Furthermore, this paper summarizes the main research direction and existing problems in plate-fin heat exchanger in FLNG. The analysis results show that plate-fin heat exchanger is the main heat exchangers during the natural gas liquefaction process in FLNG, which has a broad application prospect with the extraction of the offshore natural gas in China. [ABSTRACT FROM AUTHOR]

Coal-derived liquid fuels (CDLs) are petroleum diesel's (PD) alternatives produced by coal liquefaction. The injection and non-evaporating spray characteristics of CDLs, including diesel from direct coal liquefaction (DDCL), diesel from indirect coal liquefaction (DICL), and their blends (DBCL), were discussed. The high-pressure common rail test bench was used to evaluate the injection delay, injection rate, injection quantity, single injection heat value, and injector inlet pressure. A constant volume chamber along with high-speed camera was used to visualize the spray, then measuring the spray tip penetration distance, spray cone angle, and spray area. Besides, injection tests were conducted using injectors removed from engines that had finished durability tests fueled with DBCL and PD. The results revealed that DDCL had shorter injection delays and more mass injection quantity than PD, with an injection heat value 7 % higher at a rail pressure of 140 MPa. Regarding the spray, PD had a longer spray tip penetration distance and smaller cone angle than CDLs. On test conditions, the spray Sauter mean diameters of DDCL and DICL were over 30 % less than that of PD. Inferring from the reduction in injection rate and quantity, PD generated more clog in the injector hole than DBCL. • Injection and spray characteristics of CDLs and PD were investigated. • Single injection heat values of CDLs were higher than that of PD. • Injector hole clogging of engines fueled with DBCL and PD were reported. [ABSTRACT FROM AUTHOR]

To obtain the proper catalyst activity for direct coal liquefaction, the iron-oxides, as a precursor of iron-based catalysts, were sulfurized in the liquid medium before use. The hydrogen-donating solvent, a promising liquid medium, benefited the process design. However, it was found to be not conducive to the catalyst activity. Herein, the influence on catalysts from aromatics was investigated. Synthetic iron-oxides were sulfurized under H 2 S flow in the mixtures of decalin and selected aromatics including xylene, naphthalene, phenanthrene and pyrene. The catalyst activity was evaluated based on its performance in the catalytic hydrogenation of naphthalene. It was found that pyrene had a significant negative effect on catalyst activity, which was mainly related to the condensation of pyrene on the catalyst. The fact was that the amount and condensation degree of carbon deposits on the tested catalysts were inversely proportional to their activities. The condensation of pyrene was related to both elemental sulfur and iron species. The effect from the two factors separately on pyrene condensation was limited, while the synergetic effect when they worked together made the condensation extent increased significantly. The elemental sulfur reacted with pyrene at elevated temperatures and induced the condensation of pyrene. Besides, density-functional-theory calculation results revealed that the chemical bonds of both elemental sulfur and pyrene were weakened by iron-sulfides. • Pyrene inhibit the activity of obtained catalyst during sulfurization of iron-oxides. • Carbon deposits on catalyst is found to be responsible for the low activity. • Elemental sulfur produced from H 2 S during sulfurization induce pyrene condensation. • Iron sulfides promote condensation by activating chemical bonds of sulfur and pyrene. [ABSTRACT FROM AUTHOR]

• The molecular weights of components in SESs and TESs are generally below 2000 amu. • As increasing TET, more PAHs are dissolved, so H/C of TESs also declines. • MN is more conducive to the dissolution of large aromatic ring structures. The direct coal liquefaction (DCL) process is accompanied by the dissolution of the soluble fractions during the preheating stage. These soluble fractions remain in the system after dissolution and involve subsequent high-temperature hydro-liquefaction process, and their effect and role on the distributions and properties of products cannot be ignored. In this paper, soxhlet extraction (SE) with tetrahydrofuran (THF) and pyridine (PY) and in-situ thermal extraction (TE) in tetralin (THN) and 1-methyl naphthalene (MN) at 260–360 °C of Hami lignite (HM) and Bulianta sub-bituminous coal (BLT) were carried out to obtain SE soluble fractions (SESs) and TE soluble fractions (TESs), respectively. The effects of temperature and solvent on extraction behaviors of two coals were investigated and the structure and property characteristics of SESs and TESs were compared. The results indicate that the extraction yields of HM are higher than that of BLT, and TE significantly enhances the extraction yields, reaching 41.06 % and 36.40 % at 360 °C with THN and MN for HM, respectively. The TE yields (TEYs) increase with the raising of TE temperature (TET). The high TEYs received at 360 °C may be ascribed to the partial pyrolysis reactions of weak covalent bonds like side chain and bridge bond breaking in two coals. The main body of HM and BLT is a macromolecular network structure that is crosslinked by chemical bonds, and some low molecular weight compounds that are bound through non-covalent bond interactions constitute the guest. The SESs and TESs are mainly composed of aliphatics with high H/C, low condensation degree aromatics and oxygen-containing compounds containing C=O and C-O, with low heteroatom content and almost all of the mineral matters in raw coals are transformed to residues. There are significant differences in structures between SESs and TESs. As increasing the TET, the content of monocyclic aromatics in TESs decreases, and more polycyclic aromatics are dissolved, so H/C also declines. The weight-average molecular weights and molecular weight size distribution of TESs measured by the GPC method are generally larger than those estimated by MALDI-TOF-MS, which is correlated to the association structure formed between TESs and solvent or in TESs. [ABSTRACT FROM AUTHOR]

The enrichment of vitrinite can enhance the oil yield and conversion rate in low-rank coal liquefaction. The work evaluated the effects of surface modification on the rotary triboelectric separation of macerals. Permittivity and charge–mass ratio analysis of vitrinite and inertinite under various modified conditions demonstrated that kerosene and diesel were excellent modifiers since they keep the permittivity of macerals at a low level. The largest difference in triboelectric charge of vitrinite and inertinite was obtained when 3.0 kg/t kerosene was adopted as modifier. Rotary triboelectric separation of untreated low-rank coal indicated that the optimal separation, i.e., a vitrinite content of 65.45% and a recovery of 69.89%, was obtained at a feed rate of 1.5 g/s, a friction wheel speed of 3000 rpm, and a separation voltage of 30 kV. Under the optimum operating conditions, the optimal rotary triboelectric separation under surface modification, i.e., a vitrinite content of 69.78% and a recovery of 73.52%, was achieved when the coal was treated by 3.0 kg/t kerosene. The results demonstrated that surface modification significantly improved the rotary triboelectric separation by changing the surface electrical properties of macerals, while the excessive dosage of the modified reagent was unfavorable to achieving optimal separation. [ABSTRACT FROM AUTHOR]

Coal liquefaction residue (CLR) has a high content of carbon and organic substances. However, sulfur and inorganics pose a challenge for the high-value-added utilization of CLR. In this work, general-purpose carbon fiber was successfully prepared by the new method of chlorination–dechlorination using CLR as raw material and benzyl chloride as chlorinating agent. The effect of benzyl chloride addition amount on the property of isotropic pitch precursor and the performance of general-purpose carbon fiber were investigated. The results showed that the as-prepared pitch precursors were dominated by carbon elements and contained small numbers of hydrogen, oxygen, nitrogen, and sulfur. The characteristic peaks generated from chlorine elements were observed in both FTIR and XPS spectra. The peaks at the wavenumbers of 1490 cm−1 and 696 cm−1 corresponded to the vibration of C–Cl bond, and a tiny Cl 2p peak located at 200.0 eV was observed by reducing the noise of XPS spectra. It indicates that the trace chlorine remains in the as-synthesized isotropic pitch precursor even after undergoing dechlorination. The molecular compositions of isotropic pitches were mainly polyaromatic hydrocarbons, and the chlorination–dechlorination promotes the oligomerization of polyaromatic hydrocarbons to form dimers and trimers. Therefore, the polycondensed degree and carbon aromaticity were improved. It is known from 13C NMR analysis that the effect of chlorine–dechlorination makes the molecular structure of pitches transform more linear, thus enhancing their spinnability. In addition, the higher the amount of benzyl chloride added, the better the property of isotropic pitch was. The pitch of BC-30 and BC-40 showed excellent spinnability, stabilized property, and carbonized property compared to other pitches. The morphology of obtained carbon fiber was homogeneous and smooth without defects in surface and section. The as-prepared general-purpose carbon fiber demonstrated good tensile strength up to 1220 MPa with an average diameter of 8.5 μm. [ABSTRACT FROM AUTHOR]

The first unit in domestic that using the combination technology of ebullated bed hydrogenation + fixed bed hydrocracking to produce diesel oil and naphtha with medium and low temperature full distillate coal tar as feedstocks was successfully put into operation in a factory in Shaanxi province in August 2020. The STRONG ebullated bed hydrogenation technology independently developed by SINOPEC was used for the first time in the ebullated bed hydrogenation unit. This paper introduces the general situation of the unit and the main technological characteristics, and analyzes and summarizes the operation problems of the unit based on the first shutdown and maintenance. Through the comparison of design and operation data, the operation parameters of the unit have reached or exceeded the design value. The naphtha product yield is up to 33%, which can be used as the feedstock of reforming unit. The diesel product yield reaches 60%, which is a high quality diesel blending component. The energy consumption of the unit is 74.48 kilograms of oil equivalent per ton feedstock, which is lower than the design energy consumption. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & 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.)

A regulating valve is a key control element in the coal liquefaction industry, whose flow field distribution is related to the entropy production. In order to make a quantitative evaluation of the energy loss in the cavitation flow and calculate the magnitude and location of the hydraulic loss in the flow field more accurately, entropy production theory is employed to analyze the flow field in the regulating valve numerically. The entropy production under cavitation condition and its influence on steady-state flow force are also discussed. When the opening of the valve increases, the entropy production and energy loss change dramatically. The entropy production rate (EPR) is mainly distributed at the orifice and downstream of the regulating valve, the entropy production rate (EPR) reaches the maximum value at the orifice, and turbulent pulsation entropy production (TPEP) is the main part of the total entropy production for flow. When the valve's opening increases from 40% to 70%, the total entropy production (TEP) increases from 467.14 W/K to 630.04 W/K. The entropy production by cavitation (EPC) increases firstly and then decreases. The smallest value of EPC is 0.103 W/K at the 40% opening, while the maximum value is 0.119 W/K at 60% opening. Furthermore, the relationship between total entropy production (TEP) and steady-state flow force can be approximated by an exponential distribution. When the steady-state flow force increases, the total entropy production for flow also increases. Cavitation effect on the steady-state flow force is strengthened firstly and then weakened with increasing the valve's opening. Finally, a discriminant method based on the change of the steady-state flow force is proposed to detect whether cavitation occurs in the valve or not. The results in this paper could provided a directional and quantitative evaluation of energy loss in the regulating valve, which is help for the structural shape optimization and service life extension combining with external characteristics of the valve and internal flow field. [ABSTRACT FROM AUTHOR]

In this paper, the extraction residue of direct coal liquefaction residue-DCLR(ER) was used as raw material. The high-temperature reaction mechanism of Mo compound in DCLR(ER) was investigated using a synchronous thermal analyzer and the Factsage database. The high temperature reaction of DCLR(ER)-MoO3 in an oxygen atmosphere consists of pyrolysis of organic components at 400–600 °C, molybdenum trioxide sublimation at 747–1200 °C, and a stable stage at 600–747 °C. The thermal reaction process of the DCLR(ER)-MoS2 system in the oxygen atmosphere involves the pyrolysis of unreacted coal and asphaltene, the oxidation of molybdenum sulfide at 349–606/666 °C, the diffusion of MoO3 at 606/666–85 °C, and the sublimation reaction process of MoO3 at 854–1200 °C. The results show that the lower heating rate can promote the oxidation of the Mo compound and the sublimation of molybdenum trioxide. On the other hand, the oxides of aluminum, calcium, and iron in DCLR(ER) can inhibit the oxidative pyrolysis efficiency of the DCLR(ER)-MoS2 system. [ABSTRACT FROM AUTHOR]

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.)

Coal ash is a geomaterial with a metastable structure. This type of geomaterial is significantly susceptible to liquefaction as a result of seismic loads. An investigation of ash that is susceptible to liquefaction due to a seismic load can use the CPT penetration test. This method of investigating liquefaction was developed based on numerous penetration tests of sandy or silty–sandy soils and was developed at the Workshop on the Evaluation of Soil Liquefaction Resistance, NCEER, Salk Lake City, Utah, USA, 1996. In the present article, the results of the CPT penetration test conducted at the Rosina ash tailings pond in Žilina in Slovakia, are analyzed using the NCEER methodology. The safety factor for ash liquefaction was expressed based on the penetration resistance values measured in the CPT tests using the 'LiquefyPro' software. The safety factor in the liquefaction of the ash sediment was expressed by changing the level of seeping water in the body of the tailings pond, the unit weight of coal ash, and the seismic acceleration. [ABSTRACT FROM AUTHOR]

Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 6 Raymond N. School of Paris; the painters and the artistic climate of Paris since 1910. The evidence for a causal relationship is such that the International Agency for Research on Cancer (IARC) has classified benzo[a]pyrene as a Group 1 carcinogen; one that IARC considers to be a known cause of cancer in humans [[10]]. [Extracted from the article]

The study evaluates the feasibility of using coal liquefaction residue (DCLR) as a substitute for mineral powder and DCLR-based polymers as a substitute for cement in emulsified asphalt mixtures containing 100 % recycled asphalt pavement (RAP). This research examines the impact of various curing regimes on the functional attributes of the modified emulsified asphalt mixtures by evaluating road performance, compressive strength, and elastic modulus. The findings indicate that DCLR can effectively substitute mineral powder, maintaining the mixture's stability and durability. The "three-stage double compaction" curing technique significantly enhances mechanical properties. Furthermore, the incorporation of DCLR-based geopolymers augments the dynamic stability of the mixture, albeit slightly affecting bending strain and residual stability. The integration of DCLR-based geopolymers substantially boosts the shear resistance of cold-recycled mixtures. During the enhancement of mixture performance, DCLR primarily serves a physical filling role, whereas DCLR-based geopolymers contribute to performance improvement through physicochemical interactions. This study validates the practicality of employing DCLR in emulsified asphalt mixtures for high-temperature applications, suggesting a sustainable pathway for asphalt mixture design. • DCLR powder has the potential to substitute for natural mineral powder. • DCLR-based geopolymers boost high-temp performance in emulsified asphalt mixtures. • DCLR-based geopolymers enhance shear resistance in emulsified asphalt mixtures. • DCLR-based geopolymers and DCLR powder are suitable for use in high-temp regions. [ABSTRACT FROM AUTHOR]

• A DGC method is used to enrich the exinite and vitrinite in the exinite-rich coal. • A matrix computation is proposed to represent the exinite-rich coal bonding structure model. • Interaction between exinite and vitrinite in DCL inhibits radical's condensation. • Two stages with different linearity in X c and Y oil with Q H increased is studied. • The optimum temperature for exinite-rich coal in DCL should not exceed 440 °C. The contents of maceral components in coal are one of the key factors influencing the coal conversion in direct liquefaction. The relatively low exinite content in coal has led to a lack of study in the literature regarding its liquefaction behavior. In this study, an isopycnic density gradient centrifugation (DGC) technique was used to obtain four components of an exinite-rich coal. Eight covalent bonds concentrations of the raw coal and four components were calculated based on the results of 13C NMR, elemental analysis, and FTIR, and a matrix computation was proposed to represent the bonding structure model of exinite-rich coal. Based on the typical bonding structure model of exinite-rich coal, the liquefaction of exinite and vitrinite components was studied in a hydrogen donor solvent medium, and the interaction between exinite and vitrinite in direct liquefaction was also explored. The effect of interaction on products composition and hydrogen donation quantity were studied by comparing the experimental and theoretical values. The average aromatic ring of exinite-rich coal is three rings with approximately a quarter of substitutive degree, and the oxygen-containing functional groups in substituents are more than carbon-containing functional groups. The content of weak bonds in exinite-rich coal is 42.5 %, and with an increase in the exinite content, the alkyl side-chain and methylene bridge-chain become longer. Although the interaction between exinite and vitrinite inhibits the condensation reaction during direct liquefaction, it also occurs significantly at 455 °C, so the optimum temperature for direct liquefaction of exinite-rich coal can reach up to 440 °C. The interaction between exinite and vitrinite promotes coal conversion, reduces hydrogen consumption, and increases hydrocarbon gases, such as CH 4 and C 2 -C 3 hydrocarbons, as well as inorganic gases, such as CO and CO 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of Fe- or Ni-based catalyst on the pathway of hydrogen transfer is examined. • Fe-based catalyst minimize H-shuttle effect of solvent, while Ni catalyst enhances it. • DHA exhibits lower capacity of hydrogen donor than THN as liquefied solvent. • THN more effectively transfers gaseous H 2 to radicals from coal pyrolysis than DHA. The H-donating solvent plays a crucial role in both oil yield and products distribution during direct coal liquefaction. Meanwhile, liquefaction catalyst significantly influences the H-donating behavior of the solvent and the pathways of hydrogen transfer. In view of insufficient understanding on the impact of catalysts on H-donating behavior of solvent and hydrogen transfer pathways in direct liquefaction, in this study, non-H-donating solvents including naphthalene, 1-methylnaphthalene and pyrene (Py) and H-donating solvents including tetralin (THN) and 9,10-dihydroanthracene (DHA) were chosen as the solvents. The Shenhua nano-sized Fe-based and the prepared Ni/Al 2 O 3 catalysts were used to investigate their effect on H-donating behavior of the solvent and H-shuttling mechanism. Results show that liquefaction solvent obviously affects coal conversion and products distribution no matter Fe-based or Ni-based catalyst was used. When non-H-donating solvent is used as liquefaction solvent, coal conversion is lower than that with THN or DHA as solvent. The addition of Py to THN as solvent improves the utilization of effective hydrogen in non-catalytic liquefaction, which is ascribed to hydrogen transfer effect of Py; however, hydrogen transfer mainly occurs through direct combination of gaseous H 2 with radicals generated from coal pyrolysis in presence of Fe-based catalyst, with minimal shuttle action of solvent hydrogen. On the contrary, the Ni-based catalyst aids in enhancing the hydrogen shuttle effect of the solvent, and the hydrogen transfer path primarily involves H 2 to solvent and then to coal, which is ascribed to good hydrogenation ability of Ni-based catalyst. Under the action of Fe-based catalyst, DHA as liquefaction solvent exhibits lower H-donating capability compared to THN, and approximately 65% of total hydrogen consumption is effectively utilized for coal liquefaction, along with about 35% of total hydrogen consumption for the hydrogenation, ring opening, and side-chain scission reactions of DHA. However, about 96% of total hydrogen consumption is effectively utilized for coal liquefaction when THN used as solvent, indicating that THN as liquefication solvent is more conducive to the transfer of gaseous hydrogen to free radical fragments from coal pyrolysis compared to DHA. [ABSTRACT FROM AUTHOR]

Direct coal liquefaction residue (DCLR) is an industrial by-product from the direct coal liquefaction process. It has the unique characteristics of high carbon, high sulfur and high ash content, strong cohesiveness and low softening point, which makes DLCR a potential raw material. However, direct discharge of untreated DCLR can cause severe damage to environment and human body. Thus it is of great importance to utilize DCLR properly. In this study, solvothermal extraction of direct coal liquefaction residue (DCLR)was treated with N-methyl-2-pyrrolidone (NMP) and 1-methyl naphthalene (1-MN). In addition, molecular models of DCLR and two hypercoals (HPC: NMP-HPC, MN-HPC) were built to clarify the extraction mechanism, aiming to provide a technically feasible route to utilize DCLR and investigate the adaptation between extractant and raw materials. The structural parameters were obtained by means of industrial and elemental analysis, 13C NMR, XPS and FTIR. Subsequently, macromolecular structure models were constructed, with simulated molecular formulas C 153 H 108 N 2 O 10 S, C 206 H 168 N 6 O 7 and C 278 H 202 N 2 O 13 S, respectively. After modifying the macromolecular models by Materials Studio for geometric optimization, annealing dynamics calculation, density simulation and analysis of chemical bonds and charge layout, these models reflected the macromolecular structural characteristics precisely. On the other hand, DCLR model underwent significant changes in functional groups, branched chain length and quantity pre and post solvothermal extraction, indicating that the thermal extraction process was mainly affected by swelling behavior and pyrolysis. Meanwhile the principles of the two extractants were also different.1-MN extraction was a heat-induced relaxation, while NMP extraction was heat & solvent-induced relaxation process. This study will be helpful in expanding the utilization of DCLR and understanding of mechanism of solvothermal extraction on the macromolecular level based on modeling. [ABSTRACT FROM AUTHOR]

Schematic illustration of the preparation of porous carbons. [Display omitted] • The porous carbons with controllable architecture were fabricated by a dual-role KCl-assisted activation method. • KCl not only serves as an auxiliary template but also contributes to an enhancement in the melting of K 2 CO 3. • The prepared porous carbons possess well-developed pore structure and excellent electrochemical performance. • This work paves a path to prepare porous carbons via an environment-friendly and cost-effective route for supercapacitors. Preparation of high-performance electrode materials in a low-cost and simple way is of great significance for the application and development of supercapacitors. Herein, a dual-role KCl-assisted KOH activation method with low KOH consumption was employed to fabricate porous carbons with controllable architecture, using the coal liquefaction residue (CLR) as the raw material. It is indicated that KCl not only serves as an auxiliary template for pore-forming but also contributes to an enhancement in the melting of K 2 CO 3 , an intermediate of KOH activation, resulting in an improvement in the efficiency of KOH activation. As a consequence, the prepared samples possess highly developed pore structure even at a low KOH consumption, which endow them with excellent capacitive performance. The as-fabricated optimal porous carbon (LR-KPC-4) displays a maximum specific capacitance of 375 F g−1 at 0.5 A/g and superior rate capacity, which are much better than those of the porous carbon prepared without KCl. The fabricated symmetric supercapacitor shows a high specific capacitance of 256 F g−1 at 0.5 A/g, energy density of 8.9 Wh kg−1 at 125 W kg−1 and great cycling stability. This work demonstrates a facile strategy to efficiently convert CLR into porous carbons for high-performance supercapacitors. Meanwhile, it paves a promising way for value-added utilization of CLR. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of compatibilization methods on the compatibility between asphalt and direct coal liquefaction residue (DCLR) components to identify the key components in DCLR and asphalt that affect their compatibility. In this article, three types of compatibilizers, including benzyl alcohol (BA), dioctyl phthalate (DOP), and BA/DOP, were selected and acted on asphalt's components and DCLR's components, respectively. The molecular models of asphalt components, asphalt components with compatibilizers, DCLR components, and DCLR components with compatibilizers were established. The compatibility between DCLR and asphalt's four components, as well as between asphalt and DCLR's three components, were evaluated by solubility parameter difference (SPD) and interaction energy (IE). The compatibility between DCLR and asphalt was analyzed by Segregation test and Scanning Electron Microscope. Results indicate that the SPD and IE values between DCLR and asphalt components declined after adding compatibilizers, which implies that the repulsion decreased and the attraction increased between asphalt components and DCLR and the compatibility between asphalt components and DCLR improved. The IE values between DCLR components and asphalt increased after adding compatibilizers, which indicates that the compatibility was reduced between DCLR components and asphalt. The SPD values between DCLR components and asphalt increased after adding the BA/DOP. The SPD values between pre-asphaltene and asphalt decreased after adding the BA and DOP. The SPD value between asphaltene in DCLR and asphalt increased after adding the BA and decreased after adding the DOP. Moreover, the storage stability and homogeneity of DCLR-modified asphalt improved after adding compatibilizers, indicating that the compatibilizers enhanced compatibility between DCLR and asphalt. Finally, comparing the results of the tests, it could be found that compatibilizers preferentially acted on the asphalt components and mainly affected the aromatics in asphalt, thereby improving the compatibility between asphalt and DCLR. The effect of BA/DOP on improving the compatibility between asphalt and DCLR was better than that of BA and DOP. • The compatibility between DCLR and asphalt with four/three components was studied by SPD and IE. • Compatibilizers preferentially act on the aromatics in asphalt components. • BA/DOP is better than BA and DOP for improving the compatibility between DCLR and asphalt. [ABSTRACT FROM AUTHOR]

The excellent mechanical properties and thermal conductivity of mesophase pitch-based carbon fibers are intricately linked to the rheological properties and molecular structure of mesophase pitch (MP). In this study, spinnable mesophase pitch was prepared through hydrogenation and thermal condensation, and the impact of refined coal tar pitch (RCTP) hydrogenation on the rheological properties and molecular structure of MP was investigated. Molecular structure characterization results of hydrogenated pitch (HP) showed a significant increase in aliphatic chain structure, naphthenic structure, and methylene structure, along with an elevated H/C atomic ratio ranging from 0.602 to 0.700 with an increase in hydrogenation degree. The rheological and spinning properties of MP were assessed using a capillary rheometer, high-temperature rotational rheometer, melt spinning machine and other equipment. Results indicated a lower viscosity and softening point of MP, improved fluidity, and enhanced spinning stability with increasing hydrogenation degree. Polarizing microscope, X-ray diffraction， and Raman spectroscopy were used to characterize the molecular structure of MP. Findings emphasized that an optimal degree of hydrogenation facilitated the formation of a large domain structure and orderly stacking of MP molecules, maintaining molecular planarity to a certain extent. Excessive hydrogenation of RCTP, however, led to a reduction in the degree of order in the molecular arrangement of MP. When the H/C atomic ratio of HP ranged from 0.648 to 0.669, a notable reduction in MP system viscosity, improved spinning stability, and maintained molecular planarity were observed. During the spinning process, favorable rheology and planarity promoted the orderly arrangement of MP aromatic planar molecules along the tensile direction. This holds significant implications for preparing mesophase pitch-based carbon fiber with excellent mechanical properties and thermal conductivity. [Display omitted] • Increasing the degree of hydrogenation enhances the spinning stability of mesophase pitch (MP). • Excessive hydrogenation of refined coal tar pitch reduces the molecular flatness of MP. • Optimal hydrogenation degree facilitates the formation of a large domain structure and orderly stacking of MP molecules. [ABSTRACT FROM AUTHOR]

The co-hydroprocessing of lignite and heavy residue generates a substantial amount of tail oil, compromising the technical efficiency and posing significant environmental hazards. We proposed a cascade utilization scheme via the combination of tail-oil cycling and tail-oil co-hydrocracking, to maximize the utilization of catalytic components and enhance the conversion of heavy feedstock. At a cycling ratio of 50 wt %, the conversion efficiency of carbonaceous solids increased from 88 % to over 95 % after 5 cycles. The effluent tail oil also represented a favorable hydrocracking performance when mixed with Merey atmospheric residue. The spent catalysts and iron-containing minerals gradually accumulated in solid residues, which provided additional catalytic components for hydrogenation and coke inhibition in the co-hydroprocessing and co-hydrocracking systems. Moreover, the cycling process improved the colloidal stability and enhanced the hydrogenolysis of heavy components, effectively curbing the degradation tendency within the reaction system and producing more light oils. [Display omitted] • Tail-oil circulation promoted the conversion of heavy feedstock. • Co-hydrocracking of effluent tail oil and MRAR produced less cokes. • Enriched metal sulfides in solid residues provided sufficient catalytic components. • Improved oil property was found during the cycling process. [ABSTRACT FROM AUTHOR]