中国钢铁工业减污降碳协同控制技术发展与展望

As the largest steel-producing country,China’s steel industry has experienced rapid development in terms of production level and quality.Owing to the high consumption of coal in the iron and steel industry,air pollutants and carbon dioxide(CO_(2))show similar emission properties in flue gas.In view of the collaborative reduction of pollution and carbon emissions,the emission standards for pollutants and carbon were first analyzed,suggesting that carbon emission standards for the iron and steel industry should be accelerated.A collaborative technology system for the reduction of pollution and carbon emissions from the iron and steel industry in China is demonstrated,consisting of(1)optimization of present ultra-low emission technology,(2)low-carbon innovation for present production processes,(3)steel production process reengineering,and(4)carbon capture,utilization,and storage(CCUS).Finally,the technical prospect for collaborative reduction of pollution and carbon emissions from the iron and steel industry in China is suggested to support high-quality green development in this industry.

TOC estimation from logging data using principal component analysis

Total organic carbon(TOC)content is one of the most important parameters for characterizing the quality of source rocks and assessing the hydrocarbon-generating potential of shales.The Lucaogou Formation shale reservoirs in the Jimusaer Sag,Junggar Basin,NW China,is characterized by extremely complex lithology and a wide variety of mineral compositions with source rocks mainly consisting of carbonaceous mudstone and dolomitic mudstone.The logging responses of organic matter in the shale reservoirs is quite different from those in conventional reservoirs.Analyses show that the traditional△logR method is not suitable for evaluating the TOC content in the study area.Analysis of the sensitivity characteristics of TOC content to well logs reveals that the TOC content has good correlation with the separation degree of porosity logs.After a dimension reduction processing by the principal component analysis technology,the principal components are determined through correlation analysis of porosity logs.The results show that the TOC values obtained by the new method are in good agreement with that measured by core analysis.The average absolute error of the new method is only 0.555,much less when compared with 1.222 of using traditional△logR method.The proposed method can be used to produce more accurate TOC estimates,thus providing a reliable basis for source rock mapping.

In-situ constructed SnO_(2) gradient buffer layer as a tight and robust interphase toward Li metal anodes in LATP solid state batteries

Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP),of much interest owing to its high ionic conductivity,superior air stability,and low cost,has been regarded as one of the most promising solid-state electrolytes for next-generation solid-state lithium batteries(SSLBs).Unfortunately,the commercialization of SSLBs is still impeded by severe interfacial issues,such as high interfacial impedance and poor chemical stability.Herein,we proposed a simple and convenient in-situ approach to constructing a tight and robust interface between the Li anode and LATP electrolyte via a SnO_(2)gradient buffer layer.It is firmly attached to the surface of LATP pellets due to the volume expansion of SnO_(2)when in-situ reacting with Li metal,and thus effectively alleviates the physical contact loosening during cycling,as confirmed by the mitigated impedance rising.Meanwhile,the as-formed SnO_(2)/Sn/LixSn gradient buffer layer with low electronic conductivity successfully protects the LATP electrolyte surface from erosion by the Li metal anode.Additionally,the LixSn alloy formed at the Li surface can effectively regulate uniform lithium deposition and suppress Li dendrite growth.Therefore,this work paves a new way to simultaneously address the chemical instability and poor physical contact of LATP with Li metal in developing low-cost and highly stable SSLBs.

Process and challenges of stainless steel based bipolar plates for proton exchange membrane fuel cells

Proton exchange membrane fuel cell(PEMFC)powered automobiles have been recognized to be the ultimate solution to replace traditional fuel automobiles because of their advantages of PEMFCs such as no pollution,low temperature start-up,high energy density,and low noise.As one of the core components,the bipolar plates(BPs)play an important role in the PEMFC stack.Traditional graphite BPs and composite BPs have been criticized for their shortcomings such as low strength,high brittleness,and high processing cost.In contrast,stainless steel BPs(SSBPs)have recently attracted much attention of domestic and foreign researchers because of their excellent comprehensive performance,low cost,and diverse options for automobile applications.However,the SSBPs are prone to corrosion and passivation in the PEMFC working environment,which lead to reduced output power or premature failure.This review is aimed to summarize the corrosion and passivation mechanisms,characterizations and evaluation,and the surface modification technologies in the current SSBPs research.The non-coating and coating technical routes of SSBPs are demonstrated,such as substrate component regulation,thermal nitriding,electroplating,ion plating,chemical vapor deposition,and physical vapor deposition,etc.Alternative coating materials for SSBPs are metal coatings,metal nitride coatings,conductive polymer coatings,and polymer/carbon coatings,etc.Both the surface modification technologies can solve the corrosion resistance problem of stainless steel without affecting the contact resistance,however still facing restraints such as long-time stability,feasibility of low-cost,and mass production process.This paper is believed to enrich the knowledge of high-performance and long-life BPs applied for PEMFC automobiles.

Direct reduction swelling behavior of pellets in hydrogen-based shaft furnaces under typical atmospheres

Hydrogen-based shaft furnace process is gaining more and more attention due to its low carbon emission, and the reduction behavior of iron bearing burdens significantly affects its operation. In this work, the effects of reduction degree, temperature, and atmosphere on the swelling behavior of pellet has been studied thoroughly under typical hydrogen metallurgy conditions. The results show that the pellets swelled rapidly in the early reduction stage, then reached a maximum reduction swelling index (RSI) at approximately 40%reduction degree. The crystalline transformation of the iron oxides during the reduction process was the main reason of pellets swelling. The RSI increased significantly with increasing temperature in the range of 850-1050℃, the maximum RSI increased from 6.66%to 25.0%in the gas composition of 100%H_(2). With the temperature increased, the pellets suffered more thermal stress resulting in an increase of the volume. The maximum RSI decreased from 19.78%to 17.35%with the volume proportion of H_(2) in the atmosphere increased from 55%to 100%at the temperature of 950℃.The metallic iron tended to precipitate in a lamellar structure rather than whiskers. Consequently, the inside of the pellets became regular, so the RSI decreased. Overall, controlling a reasonable temperature and increasing the H_(2) proportion is an effective way to decrease the RSI of pellets.

Novel Au nanoparticles-inlaid titanium paper for PEM water electrolysis with enhanced interfacial electrical conductivity

Proton-exchange membrane water electrolysis(PEM WE)is a particularly promising technology for renewable hydrogen produc-tion.However,the excessive passivation of the gas diffusion layer(GDL)will seriously affect the high surface-contact resistance and result in energy losses.Thus,a mechanism for improving the conductivity and interface stability of the GDL is an urgent issue.In this work,we have prepared a hydrophilic and corrosion resistant conductive composite protective coating.The polydopamine(PDA)film on the Ti surface,which was obtained via the solution oxidation method,ensured that neither micropores nor pinholes existed in the final hybrid coatings.In-situ reduced gold nanoparticles(AuNPs)improved the conductivity to achieve the desired interfacial contact resistance and further enhanced the corrosion resistance.The surface composition of the treated samples was investigated using scanning electron microscopy(SEM),transmis-sion electron microscopy(TEM),X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FTIR).The results indicated that the optimized reaction conditions included a pH value of 3 of HAuCl_(4) solution with PDA deposition(48 h)on papers and revealed the lowest con-tact resistance(0.5 mΩ·cm^(2))and corrosion resistance(0.001μA·cm^(−2))in a 0.5 M H_(2)SO_(4)+2 ppm F−solution(1.7 V vs.RHE)among all the modified specimens,where RHE represents reversible hydrogen electrode.These findings indicated that the Au-PDA coating is very appropriate for the modification of Ti GDLs in PEM WE systems.

Hydrogen as a carrier of renewable energies toward carbon neutrality:State-of-the-art and challenging issues

Energy storage and conversion via a hydrogen chain is a recognized vision of future energy systems based on renewables and,therefore,a key to bridging the technological gap toward a net-zero CO_(2)emission society.This paper reviews the hydrogen technological chain in the framework of renewables,including water electrolysis,hydrogen storage,and fuel cell technologies.Water electrolysis is an energy conversion technology that can be scalable in megawatts and operational in a dynamic mode to match the intermittent generation of renewable power.Material concerns include a robust diaphragm for alkaline cells,catalysts and construction materials for proton exchange membrane(PEM)cells,and validation of the long-term durability for solid oxide cells.Hydrogen storage via compressed gas up to 70 MPa is optional for automobile applications.Fuel cells favor hydrogen fuel because of its superfast electrode kinetics.PEM fuel cells and solid oxide fuel cells are dominating technologies for automobile and stationary applications,respectively.Both technologies are at the threshold of their commercial markets with verified technical readiness and environmental merits;however,they still face restraints such as unavailable hydrogen fueling infrastructure,long-term durability,and costs to compete with the analog power technologies already on the market.

Dynamic modeling and simulation of deploying process for space solar power satellite receiver

To reveal some dynamic properties of the deploying process for the solar power satellite via an arbitrarily large phased array （SPS-ALPHA） solar receiver, the symplectic Runge-Kutta method is used to simulate the simplified model with the consideration of the Rayleigh damping effect. The system containing the Rayleigh damping can be separated and transformed into the equivalent nondamping system formally to insure the application condition of the symplectic Runge-Kutta method. First, the Lagrange equation with the Rayleigh damping governing the motion of the system is derived via the variational principle. Then, with some reasonable assumptions on the relations among the damping, mass, and stiffness matrices, the Rayleigh damping system is equivalently converted into the nondamping system formally, so that the symplectic Runge-Kutta method can be used to simulate the deploying process for the solar receiver. Finally, some numerical results of the symplectic Runge-Kutta method for the dynamic properties of the solar receiver are reported. The numerical results show that the proposed simplified model is valid for the deploying process for the SPS-ALPHA solar receiver, and the symplectic Runge-Kutta method can preserve the displacement constraints of the system well with excellent long-time numerical stability.

Editorial for special issue on advanced energy storage and materials for the 70th Anniversary of USTB

1. Foreword Energy storage plays a key role in the transition towards a carbon-neutral economy. By balancing power grids and saving surplus energy, it represents a concrete means of improving energy efficiency and integrating more renewable energy sources into electricity systems. A variety of technologies to store energy are developing at a fast pace and increasingly becomingmoremarketcompetitive,includingtraditional electric energy storage, thermal energy storage, and newly developed hydrogen energy storage, etc. The demand for energy storage system with high power and efficiency boosts the development in the advanced techniques and materials,such as batteries, super-capacitors, molten salts, and catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER).

New insight on correlation between the electrochemical stability and the thermal stability of high nickel cathode materials

Cycle stability and thermal safety are critical to the commercialization of nickel-rich layered materials,yet whether there is a potential correlation between these two factors is still controversial. Herein, the relationship between the cycle stability and thermal stability of nickel-rich cathode materials have been systematically studied through five different calcination temperatures of Li[NiCoMn]O(NCM83) cathode materials. The research results confirm that the cycle stability and thermal safety of nickel-rich cathode materials do not necessarily show a positive correlation. Actually, with the calcination temperature elevated, the thermal stability of the NCM83 is enhanced, while the cycle stability is degraded. This opposite correlation is not commonly reported in previous literatures. In this work, systematical characterizations demonstrate that under the experimental conditions, the capacity retention of NCM83 is mainly determined by the Li/Ni cation disorder and H2-H3 irreversible phase transition,which is optimal at lower calcination temperature. Meanwhile, the thermal stability is mainly impacted by thermal expansion characteristics and interfacial stability of cathode material, and it is dramatically improved by the mechanical strength of the secondary particles reinforced at high calcinated temperature. This study provides some new insights on understanding and designing of the high-energy cathode materials with long cycle-life and superior safety.

Investigation of the mechanism of adult-stage resistance to barley yellow dwarf virus associated with awheat-Thinopyrum intermedium translocation

Barley yellow dwarf virus(BYDV)can infect wheat(Triticum aestivum L.),leading to yield loss.Among four BYDV strains(GAV,GPV,PAV,and RMV)identified in China,BYDV-GAV is the prevailing isolate.YW642,a wheat–Thinopyrum intermedium translocation line,is resistant to BYDV isolates at both seedling and adult stages.Zhong 8601 is the wheat recurrent parent of YW642 and is susceptible to BYDV.In this study,we investigated the adult-stage resistance mechanism of YW642,measured BYDV titer and hydrogen peroxide(H_2O_2) in adult-stage leaves of YW642 and Zhong 8601 inoculated with BYDV-GAV,and identified transcriptional differences between YW642 and Zhong 8601 using microarray-based comparative transcriptomics.Enzyme-linked immunosorbent assay and H_2O_2assay showed that both BYDV titer and H_2O_2 content were markedly lower in YW642 than in Zhong 8601 at 21,28,35,and 40 days post-inoculation(dpi).The transcriptomic comparison revealed that many types of genes were significantly up-regulated at 35 dpi in adult-stage leaves of YW642 compared to Zhong 8601.The important up-regulated genes associated with the adult-stage resistance encoded 15 resistance-like proteins,pathogenesis-related proteins(such as defensin and lipid transfer proteins),protein kinase homologs,transcription factors,reactive oxygen species scavenging-related proteins,and jasmonic acid and gibberellic acid biosynthesis enzymes.These results suggest that precise expression regulation of these proteins plays a crucial role in adult-stage resistance of YW642 against BYDV infection.

Mechanism of Cathode Process of B(Ⅲ) in LiF-NaF-KBF_4 Meltby Electrochemical Titration Technique

The mechanism of cathode process of B(Ⅲ) at molybdenum and platinum electrodes in LiF-NaF-KBF4melt was studied and the transferred electron number of the reaction was calculated by means of cyclic voltammetry.The effect of adsorption of electroactive component on the electrochemical response (e. g., the voltammetric i─Ecurves) was analyzed and discussed. The 'electrochemical spectra' for linear sweep voltammetry was used to elucidate the electrode reaction accompanied by a following transform process. The results show that the reduction ofB(Ⅲ) to B(0) proceeds in reversible one step three-electron reaction and the cathode process of B(Ⅲ) is affected byproduct adsorbed strongly at the electrode surface. It is assumed that the reduction and deposition of B(Ⅲ) at molybdenum and platinum electrodes proceed in two kinds of mechanism： (1) B(Ⅲ)＋ 3e = Bads→ B (surface diffusiondeposition mechanism) and (2) B(Ⅲ) ＋ 3e = B (direct deposition mechanism).

Sulfation behavior of CuO/γ-Al_2O_3 sorbent for the removal of SO_2 from flue gas

CuO/γ-Al2O3 has been considered as a promising and recycling sorbent to remove sulfur dioxide from flue gas. In this study, a series of CuO/γ-Al2O3 sorbents with different CuO loadings were prepared by impregnation. The monolayer coverage of CuO supported on γ-Al2O3 determined by X-ray quantitative analysis was 0.275 g CuO/g （γ-Al2O3）. Below the monolayer coverage, CuO was found highly dispersed on γ-Al2O3. Thermogravimetric technique was used to study sulfation kinetics and sulfation recycling. It was found that the Langmuir kinetic adsorption model described well the experimental data at the rapid sulfation region of the CuO/γ-Al2O3 sorbent. The adsorption activation energy was 19.98 kJ/mol and the pre-exponential factor was 9.97× 10^-5 s^-1.Pa^-1. The CuO/γ-Al2O3 sorbent has shown good performance on regeneration, but long sulfation time might cause the deactivation of the CuO/γ-Al2O3 sorbent. It was also seen that the sulfated γ-Al2O3 support could not be reduced at 400℃.

How to Apply Data Mining Technology to the Study of Agricultural Information Data Resources?

This paper makes a brief description of the definition and methods of data mining.It describes the characteristics of agricultural data(value delivery,specialization,spatio-temporal bidimensionality)and the status of application of data mining technology in agriculture.

Demand and Development of New Generation of Migrant Workers in Hebei Province

A field investigation was conducted on the new generation of migrant workers in Hebei Province to understand their present situation and characteristics,based on which countermeasures and suggestions were put forward to improve the survival and development of the new generation of migrant workers.

高炉煤气脱硫技术研究进展

实施高炉煤气脱硫进行源头减排对推进钢铁行业全流程超低排放改造具有重要意义。高炉煤气含硫组分以有机硫为主,具有复杂组分共存的排放特征,本工作论述了含硫组分在不同赋存形态(SO_(2),H_(2)S和S)下的排放限值,通过硫平衡给出了排放限值间的转化关系。高炉煤气脱硫技术的瓶颈是有机硫(主要是羰基硫,COS)脱除,重点分析了用于COS水解的铝基催化剂和碳基催化剂,γ-Al_(2)O_(3)既是载体也是活性组分,而活性炭兼具催化剂和吸附剂功能;进一步阐述了煤气中复杂组分O_(2)和Cl-等对水解催化剂失活的作用机制在于生成了沉积产物。针对COS水解形成的气态H_(2)S脱除,详细对比了湿法脱除工艺中化学吸收法和催化氧化法在反应机理、脱硫剂、脱硫产物等方面的差异;在干法脱硫工艺中,对比了氧化锌、氧化铁和活性炭在反应机理、硫容、温度适应性等方面的区别。针对有机硫和无机硫的一体化吸附,简述了分子筛吸附剂的选择性吸附原理及其再生工艺。对目前已有探索应用的催化水解+湿法脱硫、催化水解+干法脱硫和一体化吸附工艺进行了初步的评价,提出了高炉煤气脱硫技术的研发重点在于如何提高水解催化剂的活性以及降低高炉煤气中复杂组分对催化剂活性的影响,提高技术的适用性。

Multi-process and multi-pollutant control technology for ultra-low emissions in the iron and steel industry

The iron and steel industry is not only an important foundation of the national economy,but also the largest source of industrial air pollution.Due to the current status of emissions in the iron and steel industry,ultra-low pollutant emission control technology has been researched and developed.Liquid-phase proportion control technology has been developed for magnesian fluxed pellets,and a blast furnace smelting demonstration project has been established to use a high proportion of fluxed pellets(80%)for the first time in China to realize source emission reduction of SO_(2)and NO_(x).Based on the characteristics of high NO_(x)concentrations and the coexistence of multiple pollutants in coke oven flue gas,low-NO_(x)combustion coupled with multi-pollutant cooperative control technology with activated carbon was developed to achieve efficient removal of multiple pollutants and resource utilization of sulfur.Based on the characteristics of co-existing multiple pollutants in pellet flue gas,selective non-catalytic reduction(SNCR)coupled with ozone oxidation and spray drying adsorption(SDA)was developed,which significantly reduces the operating cost of the system.In the light of the high humidity and high alkalinity in flue gas,filter materials with high humidity resistance and corrosion resistance were manufactured,and an integrated pre-charged bag dust collector device was developed,which realized ultralow emission of fine particles and reduced filtration resistance and energy consumption in the system.Through source emission reduction,process control and end-treatment technologies,five demonstration projects were built,providing a full set of technical solutions for ultra-low emissions of dust,SO_(2),NO_(x),SO_(3),mercury and other pollutants,and offering technical support for the green development of the iron and steel industry.

Biomimetic three-dimensional multilevel nanoarray electrodes with superaerophobicity as efficient bifunctional catalysts for electrochemical water splitting

The design and preparation of cost-effective and durable catalysts for electrochemical water splitting are significant for the development and application of hydrogen production.Herein,inspired by the underwater superaerophobicity of fish scales,a three-dimensional multilevel nanoarray electrode with superaerophobicity was designed and fabricated by the hydrothermal method to solve the bubble shielding effect in electrochemical reactions.Benefiting from the high specific surface area,superaerophobic properties,Al doping,the Al-CoS_(2)nanosheets(NSs)/nickel foam(NF)-30 exhibits outstanding electrocatalytic activity and superior durability for electrochemical water splitting in 1 M KOH.Significantly,the Al-CoS_(2)NSs/NF-30 only required extremely low overpotential of 176 mV for oxygen evolution reaction(OER)to reach a current density of 10 mA·cm^(-2).Al-CoS_(2)NSs/NF-30 was employed as bifunctional electrode for electrochemical water splitting with a cell voltage of 1.58 V at 10 mA·cm^(-2).Meanwhile,Al-CoS_(2) NSs/NF-30 exhibited excellent durability(250 h@10 mA·cm^(-2)and 50 h@100 mA·cm^(-2)).The cobalt-based catalyst(Al-CoS_(2) NSs/NF-30)with superaerophobicity exhibits excellent performance in activity and durability,therefore is a promising electrochemical water splitting catalyst.

亚熔盐高效提钒铬清洁生产技术产业化应用

在亚熔盐生产线达产达效期间,对钒渣液相氧化、液固分离、钒酸钠结晶、三效蒸发等工序进行了研究。结果表明,在纳微曝气氧化及规模放大效应共同作用下,亚熔盐示范工程可实现较低温度(140~180℃)和较低压力(0.6~1.0 MPa)下钒和铬的高效同步提取,钒和铬的转化率分别为93%和85%;对不同原料来源的钒渣,纳微曝气亚熔盐技术均体现出优异的浸出性能;全自动立式压滤机采用三级逆流洗涤方式,保证了尾渣含水率低于30wt%,钒含量低于0.15wt%,铬含量低于0.05wt%;选用OSLO冷却结晶器进行钒酸钠结晶,钒酸钠结晶率达到61.5%;通过在三效系统蒸汽接口处增设减温减压器,实现循环碱液浓度由试生产初期的45wt%提高至50wt%。利用亚熔盐产线对传统钠化焙烧工艺废水处理过程中产生的钒铬泥进行钒铬浸出,在反应温度175℃、反应压力0.65 MPa、进出料速度0.25 t/h的工作条件下实现了钒铬泥中钒和铬的高效浸出,钒和铬的浸出率分别为93.68%和96.76%。当溶液中铬浓度达到25~30 g/L后,铬酸钠结晶工序可保证将每次液相氧化反应溶出的铬全部结晶析出,铬酸钠的结晶率为17.65%。

钢铁行业烟气多污染物协同控制技术应用实践

本研究分析了钢铁企业焦化和烧结两个重点工序中烟气污染物排放现状和钢铁行业当前的环保政策。对焦化及烧结烟气污染物的排放特征进行了分析,并通过对比燃煤电厂烟气特点,提出可以综合电厂烟气治理模式和自身特点改进的技术路线。结合某大型国有钢铁企业的脱硫脱硝装备对其环保现状进行了分析。针对焦化和烧结工序的典型污染物硫、硝、尘现有的源头减排、过程控制及末端处理技术,分析其优缺点。进而提出了3条可实现烟气污染物超低排放的技术路线,即半干法脱硫耦合选择性催化还原脱硝、半干法/湿法耦合臭氧氧化脱硝、活性焦脱硫脱硝一体化技术,重点介绍了这些技术在某大型钢铁企业的应用实践及应用效果。并基于全过程耦合技术,分别在焦化和烧结工序中提出了多污染物协同去除技术及应用,即焦炉低氮燃烧技术耦合末端活性焦多污染物协同控制技术、烧结烟气循环技术耦合末端活性焦多污染物协同控制技术。最后结合几种技术路线的应用实践,对未来钢铁产业的烧结及焦化工序超低排放技术的选择提出合理化建议。要点:(1)对钢铁厂焦化和烧结工序的烟气污染物排放现状进行了分析。(2)综述了污染物硫、硝、尘现有的脱除技术,分析其优缺点并提出可超低排放的技术路线。(3)具体阐述了超低排放的技术路线在钢铁企业的应用状况。