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Preparation and Swelling Kinetic Analysis of Poly (HPMC-co.AA-co.AM) Super Absorbent Resin

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 790-799页

作者：马砺 WANG Xin LIU Xixi WEI Gaoming GUO Ying School of Safety Science and Engineering Xi’an University of Science and TechnologyXi'an 710054China Key Laboratory of coal Fire Disaster Prevention Xi’an University of Science and TechnologyXi'an 710054China School of Energy Engineering Xi’an Uni-versity of Science and TechnologyXi'an 710054China Yanzhou coal Mining co. Ltd.Zoucheng 237500China

Super absorbent resin(SAR)is prepared by aqueous high temperature polymerization using hydroxypropyl methylcellulose(HPMC)as monomer backbone material,acrylic acid(AA)and acrylamide(AM)as the graft co.olymer monomer,potassium persulfate(KPS)as the initiator to generate free radicals,and N,N`-methylenebisacrylamide(MBA)as cross-linking agent for cross-linking ***,the influence of individual factors on the water absorption is investigated,and these factors are mainly AA,AM,KPS,MBA,HPMC,and reaction *** optimized co.ditions are obtained by the experiment repeating for several *** water absorption multiplicity and salt absorption multiplicity under the co.ditions are 782.4 and 132.5 g/g,***,the effects of different temperatures and salt co.centrations on its water absorption,as well as the swelling kinetics of SAR are *** is indicated the water-absorbing swelling process is mainly caused by the difference in water osmotic pressure and Na+co.centration inside and outside the cross-linked molecular structure of the resin,which is not only co.sistent with the quasi-seco.dary kinetic model,but also with the Fick diffusion model.

关键词： super absorbent resin swelling kinetics water absorption graft co.olymerization hydroxypropyl methyl cellulose

Three-dimensional stability calculation method for high and large co.posite slopes formed by mining stope and inner dump in adjacent open pits

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International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao Liang Dong Wang Guanghe Li Guangyu Sun Mingyu Yu Dong Xia Chunjian Ding co.lege of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua coal industry co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability ***,with the advancement of dump engineering,co.posite slopes often exhibit significant 3D mechanical ***,it is of significant importance to develop an effective 3D stability calculation method for co.posite slopes to enhance the design and stability co.trol of open-pit slope *** the co.posite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of co.posite slopes and establishes spatial shape equations for the sliding *** integrating the shear resistance and sliding force of each row of microstrip co.umns onto the bottom surface of the strip co.responding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is ***,a co.prehensive 3D stability calculation method for co.posite slopes is developed,and the quantitative relationship between the co.rdinated development distance and its 3D stability co.fficients is *** analysis reveals that the failure mode of the co.posite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear *** spatial form equation of the sliding mass co.prises an ellipsoid and weak plane *** analysis revealed that when the co.rdinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the co.posite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for co.posite ***,the3D stability co.fficient of the co.posite slope exhibits an exponential co

关键词： co.posite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability co.rdinated development distance

co.aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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Science China Chemistry 2024年第3期67卷 1017-1027页

作者： Bei Liu Fan Wang Xiaomeng Dou Pengfei Li Hongwei Xiang Yong Yang Peng He State Key Laboratory of coal co.version Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Department of Chemistry Tsinghua UniversityBeijing 100084China National Energy R&D Center for coal to Liquid Fuels Synfuels China Technology Co.Ltd.Beijing 101407China University of Chinese Academy of Sciences Beijing 101408China Leibniz-Institut für Katalyse e.V.an der Universitat Rostock Rostock 18059Germany

The co.aromatization of methane with higher hydrocarbons represents a promising route to valorize methane, an abundant but underexploited carbon resource. In this study, we elucidate a novel approach to enhance the catalytic co.aromatization of hexane and methane by co.fining Pt within zeolite catalysts and modulating its electron density. Our findings show that encapsulating Pt within MFI structure is pivotal for activating the feedstock and fostering the formation of aromatic products. Interaction between K atoms and the silanol nest forms siloxy groups which are critical for the stabilization of Pt species. Tuning the K co.tent in PtSn@MFI catalysts adeptly alters the electronic co.figuration of Pt clusters. This modification is co.roborated by infrared and X-ray photoelectron spectrosco.y analysis, and density functional theory calculations. Remarkably, the catalyst with 0.8 wt% K exhibits an optimal Pt electron density, driving its superior efficacy in the co.aromatization reaction, co.verting 0.78 mol of methane for each mole of hexane processed. By employing ~(13)C isotopic labeling and solid-state NMR studies, we demonstrate the participation of methane in the adsorbed species inside the zeolite channel and its inco.poration to the benzyl site of the substitute group and phenyl rings in aromatic co.pounds, undersco.ing the importance of Pt encapsulation.

关键词： Pt encapsulation MFI zeolite methane activation co.aromatization ^(13)C solid-state NMR

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High-efficiency co.(2) sequestration through direct aqueous carbonation of carbide slag: determination of carbonation reaction and optimization of operation parameters

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Frontiers of Environmental Science & Engineering 2024年第1期18卷 157-167页

作者： Zhiqiang Wang Longpeng Cui Yanfang Liu Jili Hou Hongwei Li Liang Zou Fuxia Zhu Department of coal and Syngas co.version Sinopec Research Institute of Petroleum Processing Co.Ltd.Beijing 100083China

Under the dual-carbon target, co.(2) mineralization through solid wastes presents a mutually beneficial approach for permanent carbon emission reduction at a low material co.t, while also enabling the resource utilization of these wastes. However, despite its potential, a co.prehensive understanding about the effect of industrial solid waste properties and operating parameters on the carbonation process, and the mechanism of direct aqueous carbonation is still lacking. A series of experiments were co.ducted to co.pare the carbonation performance of fly ash, steel slag, and carbide slag. Subsequently, co.(2) mineralization by carbide slag was systematically studied under various operating parameters due to its high co.(2) sequestration capacity. Results showed the reactivity of CaO and Ca(OH)2 was higher than that of CaO·SiO_(2) and 2CaO·SiO_(2). Carbide slag demonstrated a sequestration capacity of 610.8 g co.(2)/kg and carbonation efficiency ζCa of 62.04% under the co.ditions of 65 ℃, 1.5 MPa initial co.(2) pressure, 15 mL/g liquid-to-solid ratio, and 200 r/min stirring speed. Moreover, the formation of carbonates was co.firmed through XRD, SEM-EDS, TG, and FTIR. A mechanism analysis revealed that initially, the rate of the carbonation process was primarily co.trolled by the mass transfer of co.(2) in the gas–liquid interface. However, the rate-determining step gradually shifted to the mass transfer of Ca2+ in the solid–liquid interface as the reaction time increased. This study lays the foundation for the large-scale implementation of co.(2) sequestration through carbide slag carbonation.

关键词： Industrial by-products Direct aqueous carbonation co.(2)sequestration Mass transfer

Flame Morphology and Characteristic of co.Firing Ammonia with Pulverized coal on a Flat Flame Burner

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Journal of Thermal Science 2024年第5期33卷 1935-1945页

作者： WANG Shengye CUI Mingshuang LIU Pengzhong DI Yi NIU Fang China coal Research Institute Beijing 100013China Beijing Tiandi Rongchuang Technology co.Ltd. Beijing 100013China National Energy Technology&Equipment Laboratory of coal Utilization and Emission co.trol Beijing 100013China

Ammonia as a new green carbon free fuel co.co.bustion with coal can effectively reduce co.(2)emission,but the research of flame morphology and characteristics of ammonia-coal co.co.bustion are not *** this work,we studied the co.co.bustion flame of NH_(3)and pulverized coal on flat flame burner under different oxygen mole fraction(X_(i,O_(2)))and NH_(3)co.firing energy ratios(E_(NH_(3))).We initially observed that the introduction of ammonia resulted in stratification within the ammonia-coal co.co.bustion flame,featuring a transparent flame at the root identified as the ammonia co.bustion *** to challenges in visually observing the ignition of coal particles in the ammonia-coal co.co.bustion flame,we utilized Matlab software to analyze flame images across varying E_(NH_(3))and X_(i,O_(2)).The analysis indicates that,co.pared to pure coal co.bustion,the addition of ammonia advances the ignition delay time by 4.21 ms to 5.94 *** E_(NH_(3))increases,the ignition delay time initially decreases and then ***,an increase in X_(i,O_(2))results in an earlier ignition delay *** burn-off time and the flame divergence angle of pulverized coal demonstrated linear decreases and increases,respectively,with the growing ammonia *** addition of ammonia facilitates the release of volatile matter from coal ***,in high-ammonia environments,oxygen co.sumption also impedes the surface reaction of coal ***,measurements of gas co.position in the ammonia-coal flame flow field unveiled that the generated water-rich atmosphere intensified coal particle gasification,resulting in an elevated co.centration of ***,nitrogen-co.taining substances and co.e produced during coal particle gasification underwent reduction reactions with NO_(x),leading to reduced NO_(x)emissions.

关键词： co.firing ammonia with coal flame characteristic gas co.ponent ignition delay time burn-off time flame divergence angle flat flame burner flame morphology

Machine learning predicts atomistic structures of multielement solid surfaces for heterogeneous catalysts in variable environments

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The Innovation 2024年第2期5卷 79-87页

作者： Huan Ma Yueyue Jiao Wenping Guo Xingchen Liu Yongwang Li Xiaodong Wen State Key Laboratory of coal co.version Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China University of Chinese Academy of Sciences Beijing 100049China National Energy Center for coal to Liquids Synfuels China Co.Ltd.Beijing 101400China Beijing Advanced Innovation Center for Materials Genome Engineering IndustryUniversity Cooperation Base between Beijing Information S&T University and Synfuels China Co.Ltd.Beijing 100101China

Solid surfaces usually reach thermodynamic equilibrium through particle exchange with their environment under reactive co.ditions.A prerequisite for understanding their functionalities is detailed knowledge of the surface co.position and atomistic geometry under working *** to the large number of possible Miller indices and terminations involved in multielement solids,extensive sampling of the co.positional and co.formational space needed for reliable surface energy estimation is beyond the sco.e of ab initio ***,we demonstrate,using the case of iron carbides in environments with varied carbon chemical potentials,that the stable surface co.position and geometry of multielement solids under reactive co.ditions,which involve large co.positional and co.formational spaces,can be predicted at ab initio accuracy using an approach that co.bines the bond valence model,Gaussian process regression,and ab initio *** the atomistic structure of surfaces under working co.ditions paves the way toward identifying the true active sites of multielement catalysts in heterogeneous catalysis.

关键词： surfaces solids environments

Mechanical properties and energy evolutions of burst-prone coal samples with holes and fillings

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International Journal of coal Science & Technology 2024年第3期11卷 176-189页

作者： Yukai Fu Yongzheng Wu Junchen Li Penghe Zhou Zhuoyue Sun Jie He CCTEG coal Mining Research Institute Beijing100013China coal Mining and Designing Department Tiandi Science and Technology Co.Ltd.Beijing100013China coal Mining and Designing Branch China Coal Research InstituteBeijing100013China Resource Engineering Department China University of Mining and TechnologyBeijing100083China

During the mining process of impact-prone coal seams,drilling pressure relief can reduce the impact propensity of the coal seam,but it also reduces the integrity and strength of the coal mass at the side of the ***,studying the mechanical properties and energy evolution rules of coal samples co.taining holes and filled structures has certain practical significance for achieving co.rdinated co.trol of coal mine rockburst disasters and the stability of roadway surrounding *** achieve this aim,seven types of burst-prone coal samples were prepared and subject to uniaxial co.pression experiments with the aid of a TAW-3000 electro-hydraulic servo testing ***,the stress–strain curves,aco.stic emission signals,DIC strain fields and other data were co.lected during the ***,the failure modes and energy evolutions of samples with varying drilled hole sizes and filling materials were *** results show that the indexes related to burst propensity of the drilled coal samples decline to some extent co.pared with those of the intact one,and the decline is positively co.elated to the diameter of the drilled *** hole filling,the strain co.centration degree around the drilled hole is lowered to a certain degree,and polyurethane filling has a more remarkable effect than cement ***,hole filling can enhance the strength and deformation resistance of *** drilling can accelerate the release of accumulated elastic strain energy,turning the aco.stic emission events from low-frequency and high-energy ones to high-frequency and low-energy ones,whereas hole filling can reduce the intensity of energy *** experimental results and theoretical derivation demonstrate that hole filling promotes coal deformability and strength mainly by weakening stress co.centration surrounding the drilled ***,the fillings can achieve a better filling effect if their elastic modulus and Poisson’s ratio are closer

关键词： Rock mechanics coal Mechanical properties Hole filling Energy evolution

Understanding the co.bustion behavior of electric bicycle batteries and unveiling its relationship with fire extinguishing

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Journal of Energy Chemistry 2024年第4期91卷 609-618页

作者： Zhanglong Yu Xueling Shen Ran Xu Zheng Wang Zengming Wan Mingyang Chen Yi Cui Yanyan Fang Xiaoli Ma China Automotive Battery Research Institute co. Ltd.Beijing 101407China China Grinm Group co. Ltd.Beijing 100088China Ministry of industry and Information Technology Equipment Industry Development CenterBeijing 100846China Hefei Guoxuan High-tech Power energy co. Ltd.Hefei 230000AnhuiChina

In this study,a detailed analysis of the co.bustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was *** research included quantitative measurements of the co.bustion duration,flame height,co.bustion temperature,heat release rate,and total heat *** results indicated that LMO batteries exhibited higher co.bustion temperatures of 600–700°C,flame heights of 70–75 cm,a significantly higher heat release rate of40.1 k W(12 Ah),and a total heat release of 1.04 MJ(12 Ah)co.pared to LFP batteries with the same *** on these experimental results,a normalized total heat release(NORTHR)parameter was proposed,demonstrating good universality for batteries with different *** this parameter,quantitative calculations and optimization of the extinguishing agent dosage were co.ducted for fires involving these two types of batteries,and the method was validated by extinguishing fires for these two types of battery packs with water-based extinguishing fluids.

关键词： co.bustion behavior Electric bicycle Lithium-ion battery Fire extinguishing Normalized total heat release

Energy mechanism of bolt supporting effect to fissured rock under static and dynamic loads in deep coal mines

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International Journal of Mining Science and Technology 2024年第3期34卷 371-384页

作者： Deyuan Fan Xuesheng Liu Yunliang Tan Xuebin Li Shenglong Yang co.lege of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Disaster Prevention and co.trol Shandong University of Science and TechnologyQingdao 266590China National Energy Group Ningxia coal industry co. Ltd.Yinchuan 753001China

The stability co.trol of fissured rock is difficult,especially under static and dynamic loads in deep coal *** this paper,the dynamic mechanical properties,strain rate evolution and energy dissipation of fissured and anchored rocks were respectively obtained by SHPB *** was found that bolt can provide supporting efficiency-improving effect for fissured rock against dynamic disturbance,and this effect increased quadratically with decrease in anchoring ***,the energy dissipation mechanism of anchored rock was obtained by slipping ***,bolt energy-absorbing mechanism by instantaneous tensile-shear deformation was expressed based on material mechanics,which was the larger the anchoring angle,the smaller the energy absorption,and the less the co.tribution to supporting efficiency *** this basis,the functional relationship between energy dissipation of anchored rock and energy absorption of bolt was *** the coal-gangue separation system of Longgu coal mine as an example,the optimal anchoring angle can be determined as 57.5°–67.5°.Field monitoring showed fissured rock with the optimal anchoring angle,can not only effectively co.trol the deformation,but also fully exert the energy-absorbing and efficiency-improving effect of bolt *** study provides guidance to the stability co.trol and supporting design for deep engineering under the same or similar co.ditions.

关键词： Static and dynamic loads Anchored rock Energy absorption Anchoring angle Engineering verification