Prospects for green steelmaking technology with low carbon emissions in China

The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this sector.In this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is discussed.Additionally,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment strategies.Furthermore,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”relationship.Overall,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is discussed.In conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.

Current situation of carbon emissions and countermeasures in China's ironmaking industry

The iron and steel industry(ISI) involves high energy consumption and high pollution. ISI in China, a leading country in the ISI,consumed 15% of the country’s total energy and produced more than 50% of the global ISI’s carbon emissions. Therefore, in the context of global low-carbon economy and emission reduction requirements, low-carbon smelting technology in the ISI has attracted increasingly more attention in China. This review summarizes the current status of carbon emissions and energy consumption in China’s ISI and discusses the development status and prospects of low-carbon ironmaking technology. The main route to effectively reducing carbon emissions is to develop a gas-based direct reduction process and replace sintering with pelletizing, both of which focus on developing pelletizing technology. However,the challenge of pelletizing process development is to obtain high-quality iron concentrates. Consequently, the present paper also summarizes the development status of China’s mineral processing technology, including fine-grained mineral processing technology, magnetization roasting technology, and flotation collector application. This paper aims to provide a theoretical basis for the low-carbon development of China’s ISI in terms of a dressing–smelting combination.

Carbon dioxide emissions reduction technology and its application prospects in the steel industry

Fossil-fuel burning greenhouse gas induced global warming has been recognized as global environmental problems,reduce and ultimately control the energy production in the use of CO_2 emissions, global energy production will be a major challenge.As a highly intensive materials and energy,iron and steel enterprises,need to be invested to produce one ton of steel about two tons of material and 0.7 t of standard coal energy,and while producing two tons of CO_2.Therefore,reducing CO_2 emissions from iron and steel industry has become the focus of the global steel industry.This paper describes an integrated domestic and international measures to control carbon dioxide emissions research progress and future technology trends, with emphasis on the domestic steel industry emissions of carbon dioxide status of technology development and industrialization of implementation of the proposed on this basis,including dry quenching technology, gas,power generation,coal moisture control technology,blast furnace injection plastics technology,the use of coking process for treating municipal waste plastics technology,sintering heat generation,low pressure saturated steam for power generation,metallurgical slag heat recovery technology,coke oven gas hydrogen technology and the other key technologies energy saving technologies,including the development,promotion and popularization of the steel industry in China will be the CO_2 emission reduction technology direction and focus.At this stage,the Chinese steel industry can be improved the energy efficiency and recycling of waste heat and energy,reduce unit GDP,CO_2 emissions;but in the long run,should increase CO_2 capture and storage on the input of technology can possible effective control of the adverse effects of CO_2 emissions.

Does enterprise digitization reduce carbon emissions? Evidence from China

The digital transformation and expansion of businesses will provide China’s low-carbon economic develop‐ment strategy with fresh impetus in the backdrop of the emerging digital economy and environmentally friendly growth.This article measures the level of enterprise digitization using two methods:the enterprise digitization index and text analysis word frequency statistics.Additionally,carbon emissions are obtained by measuring various types of emissions according to the carbon emission classification range standard.To ac‐count for endogeneity and unobservable variables,relative indicators,such as the rate of increase for company emissions of carbon,are utilized.Using microdata from Chinese listed firms from 2011 to 2021,this study ex‐amines the implications of corporate digitization on enterprise carbon emissions.This study further analyzes the transmission mechanism and investigates the function of green finance in controlling corporate digitiza‐tion and reducing corporate carbon emissions by distinguishing between two types of green patents.Research shows that businesses’carbon emissions are greatly reduced as a consequence of getting digital.Even after performing several robustness and endogeneity tests,the conclusion still remains valid.According to mecha‐nism analysis,which demonstrates that the main strategy for reducing corporate emissions of carbon through the digitalization of enterprises is to promote innovation in green technology.The regulation of green finance in enterprise digitalization will further reduce corporate carbon emissions.According to the analysis of hetero‐geneity,state-owned businesses and those situated in areas with stringent environmental regulations are more significantly impacted by enterprise digitization on corporate carbon emissions.This article discusses the mechanism of promoting corporate carbon emissions through digitalization,expands on relevant research on corporate digitalization,and analyzes the achievable paths of corporate digitalization and low-carbon develop‐ment strategies.

Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

The formulae for parameters of a negative electron affinity semiconductor(NEAS)with large mean escape depth of secondary electrons A(NEASLD)are deduced.The methods for obtaining parameters such asλ,B,E_(pom)and the maximumδandδat 100.0 keV≥E_(po)≥1.0 keV of a NEASLD with the deduced formulae are presented(B is the probability that an internal secondary electron escapes into the vacuum upon reaching the emission surface of the emitter,δis the secondary electron yield,E_(po)is the incident energy of primary electrons and E_(pom)is the E_(po)corresponding to the maximumδ).The parameters obtained here are analyzed,and it can be concluded that several parameters of NEASLDs obtained by the methods presented here agree with those obtained by other authors.The relation between the secondary electron emission and photoemission from a NEAS with large mean escape depth of excited electrons is investigated,and it is concluded that the presented method of obtaining A is more accurate than that of obtaining the corresponding parameter for a NEAS with largeλ_(ph)(λ_(ph)being the mean escape depth of photoelectrons),and that the presented method of calculating B at E_(po)>10.0 keV is more widely applicable for obtaining the corresponding parameters for a NEAS with largeλ_(ph).

Research on Electromagnetic Acoustic Emission Signal Recognition Based on Local Mean Decomposition and Least Squares Support Vector Machine

Electromagnetic acoustic emission technology is one of nondestructive testing, which can be used for defect detection of metal specimens. In this study, round and cracked metal specimens, round metal specimens, and intact metal specimens were prepared. And the electromagnetic acoustic emission signals of the three specimens were collected. In addition, the local mean decomposition(LMD), Autoregressive model(AR model) and least squares support vector machine (LSSVM) algorithms were combined to identify the eletromagnetic acoustic emission signals of round and cracked, round, and intact specimens. According to the algorithm recognition results, the recognition accuracy of can reach above 97.5%, which has a higher recognition rate compared with SVM and BP neural network. The results of the study show that the algorithm is able to identify quickly and accurately crack defect in metal specimens.

BIM技术在建筑碳排放计算领域研究进展

结合国内外相关文献,对BIM技术在建筑碳排放计算领域的研究进展进行综述。通过对研究进程的归纳,以及对建筑碳排放计算政策、计算方法、BIM技术适用性等影响因素的分析,总结BIM技术在建筑碳排放计算领域的研究现状。基于当前研究成果,将BIM技术在建筑碳排放计算领域的研究内容划分为理论方法、工具平台、应用价值三个层面。理论方法主要关注计算边界和计算方法的确定、BIM模型的数据提取方式以及BIM模型的参数扩展内容;工具平台主要探讨BIM建模工具、人工处理及算法程序、BIM软件插件、BIM平台系统的具体应用;应用价值主要体现基于BIM技术的建筑碳排放计算在建筑设计、物化、运营等各阶段的成果效益。三个层面虽已取得许多研究成果但也存在问题和难点。未来的研究可以在数字技术融合和信息管理完善两个方面深入发展。

高质量发展下中国工业企业碳减排路径选择

管理改进与技术创新是工业企业实现高质量减排的两大关键路径。运用Shapley值分解方法实证测度了技术创新与管理改进对工业企业碳减排技术进步效率的贡献作用。结果发现,整体上技术创新与管理改进的贡献率分别为28.45%和71.55%,并且二者贡献率在不同类型特征企业之间存在明显差异。随着企业技术进步水平、雇佣规模和能耗水平的提升,技术创新的贡献率逐步递减,而管理创新的贡献率则呈现递增趋势。首次对企业管理改进与技术创新对碳排放效率的贡献进行测度,为优化“双碳”目标政策与指导企业减排行动提供有益参考。

绿色技术创新对城市碳减排影响的区域差异和收敛性——来自地级市层面的经验证据

运用我国299个城市的面板数据构建空间杜宾模型,实证研究绿色技术创新对城市碳排放影响的区域差异性和收敛性。结果表明:我国绿色技术创新可以降低碳排放水平,且存在空间关联效应。横向来看,不同区域的绿色技术创新对碳排放的影响具有明显的区域差异性,东部、长三角、珠三角等经济发达地区的影响效应更强,中西部、京津冀等地区相对较弱。纵向来看,2015年以来绿色技术创新对碳排放影响的区域差异持续收敛,根源在于区域经济发展差距的缩小。未来持续推进绿色技术创新、缩小区域发展差距是实现“双碳”目标的必由之路。

数字经济与新型城镇化:作用机制和门槛效应

随着新一代信息技术蓬勃发展,数字经济无疑是实现新型城镇化的必然选择。本文基于2013~2022年30个省(区、市)的面板数据,通过构造数字经济发展水平指数与新型城镇化水平指数研究数字经济对新型城镇化的影响,并引入技术创新和碳减排分析数字经济驱动新型城镇化的作用机制。研究发现,数字经济对我国新型城镇化的建设具有明显的推动作用,在新型城镇化水平低的省(区、市)与中部地区提升效果更明显;机制分析表明,技术创新和碳减排是数字经济促进新型城镇化的重要传导机制;通过进一步的门槛检验发现,数字经济对新型城镇化的推动作用因产业结构的不断升级呈现出先正后负的特征。研究结论可为加速释放数字经济红利,推动新型城镇化发展提供经验证据和政策启示。

智慧降碳:金融科技发展的城市碳减排效应研究

深入研究金融科技发展对城市碳排放量的影响及作用机制,对精准制定碳减排政策、发展低碳经济、推动城市智慧降碳具有重要的理论和现实意义。区别于以往区域内单一维度的研究,本文测算了中国城市的金融科技发展指数,基于2011~2019年中国264个城市的面板数据,从区域内和区域间两个方面检验了金融科技发展对城市碳排放量的影响效应及作用机制。结果显示:区域内金融科技发展能够显著降低城市二氧化碳的排放量,这一结论在使用工具变量缓解内生性以及替换金融科技发展指标等一系列稳健性检验后仍然成立;机制分析表明金融科技能够通过提高技术创新水平和资源配置效率两个途径降低城市碳排放量;区域间金融科技发展水平和二氧化碳排放量具有显著的空间关联性,金融科技虽然能降低本地城市二氧化碳的排放量,但会促进周边城市二氧化碳排放量,呈现出“以邻为壑”的现象。基于区域内和区域间金融科技碳减排效应的不同表现进行进一步研究,发现金融科技的碳减排效应在北部城市显著强于南部城市、在非城市群城市显著强于城市群城市、在其他城市显著强于中心城市。

碳交易下驱动企业碳减排的碳配额机制

碳配额是碳交易的基础,有效的碳配额不是为了抑制生产,而是驱动企业实施低碳技术。针对碳配额有效性设定问题,设计优化了驱动企业降低单位产品的碳排放水平的碳配额机制,得到了碳配额机制有效区间,重点分析了影响碳配额有效性的关键因素。碳配额有效性表明,单位产品初始碳排放量和减排成本系数均是影响碳配额机制有效性的关键因素,合理降低碳交易价格、提高非减排成本和价格敏感性能增大产量碳配额机制的有效性。当减排技术得到改进与提升后,减排成本系数减小,政府单位产品免费碳配额量紧缩,但制造商和零售商利润都降低,此时政府应积极引导消费者购买低碳产品,提高市场需求量。

绿色技术创新对碳排放的影响效应——非线性中介效应与调节效应分析

绿色技术创新是解决环境污染和实现碳减排目标的重要手段。基于2011—2021年中国内地271个地级及以上城市面板数据,使用参数与非参数方法检验绿色技术创新对碳排放的非线性影响,分析能源消费结构及产业结构的中介作用,同时探讨环境规制、科创支持、市场化程度和公众关注的调节作用。研究发现:①基准回归结果表明,绿色技术创新与碳排放呈显著倒“U”型关系;②异质性检验结果表明,倒“U”型关系仅在非资源型城市、低碳试点城市和高质量绿色技术创新体现明显;③中介效应检验结果表明,绿色技术创新既能通过优化能源消费结构降低碳排放,又会通过阻碍产业结构升级增加碳排放;④调节效应分析结果表明,公众关注、科创支持和市场化程度对绿色技术创新与碳排放倒“U”型关系起正向调节作用,使倒“U”型曲线更陡峭,而环境规制对绿色技术创新与碳排放倒“U”型关系起负向调节作用,使倒“U”型曲线更平缓。据此,提出提升绿色技术创新能力、推动清洁能源发展、加强政策配套支持、完善市场机制、构建政府公众共治体系等建议。

温室气体管控纳入化工园区规划环评的技术方法探索和实证研究

《中共中央国务院关于深入打好污染防治攻坚战的意见》中明确提出“将温室气体管控纳入环评管理”,温室气体管控纳入环评已成为深入推进碳达峰行动的重要举措。产业园区是控制污染物和温室气体排放增量的重要载体,是推进减污降碳源头防控的重要抓手。该研究重点围绕协同减污降碳优化规划方案这一关键问题,探索产业园区规划环评中开展温室气体评价的技术方法,并以某石化园区为例开展了实践探索。为了在环评中科学、合理地分析和评价温室气体减排潜力,从两方面探索评价技术方法:一是温室气体与大气耦合评价方法,开展温室气体评价重点排放设施能效分析,结合大气评价中空气质量目标改善要求和初步模拟预测结果,联合提出淘汰高耗低效热源设施、分阶段推进清洁能源替代的规划调整建议;二是研究创新温室气体评价和循环经济分析紧密结合的环评方法,遵循化工园区协同、合作、共享的一体化设计理念和循环经济理念,以资源循环降碳、能效提升降碳为目标,充分发挥化工园区碳固定、碳消纳的天然优势,促进园区内产业链协同。实证研究表明:①通过全面识别园区减污和降碳的关键环节,以“提效-控煤”为主线,温室气体评价与大气评价联合提出热源点整合方案;聚焦园区CO_(2)资源化利用、能源梯级利用,推动两家企业6套装置实施CO_(2)回收,并实施聚碳酸酯、碳酸乙烯酯等CO_(2)产业链利用项目,将零散企业余热资源统一纳网,实现余热余压利用,很好地验证了前述技术方法的可行性,以及温室气体评价对能源规划方案和产业循环经济方案的优化调整作用。②基于现行产业园区环评的评价技术流程,采用全过程纳入模式,提出了温室气体全过程评价技术框架,即现状评价“挖潜力”、规划分析“融理念”、影响识别“定目标”、影响评价“评趋势”、方案论证“明措施”、调整建议“优方案”。此外,对未来研究提出展望,一是增强污染防治与气候治理的协同性,二是关注难以量化的新排放源和非二氧化碳温室气体,三是结合不同园区面临的能源转型和环境目标压力,形成差异化的温室气体减排方案。该研究提出的技术框架和评价方法为优化化工园区环评源头管控作用起到有力支撑,具有重要的现实意义。

国有资本入驻是否有助于民营企业减排

国有资本是推动经济绿色转型的重要引擎,国有资本入驻民营企业,不仅可以有效规范民营企业污染排放行为,还可以通过打破民营企业发展桎梏以赋予企业创新活力,对于实现“双碳目标”和推动中国式现代化发展具有重要意义。本文运用工业企业与绿色发展数据库的匹配数据,考察国有资本入驻对民营企业减排行为的影响。研究发现,国有资本入驻后可有效减少民营企业污染排放,并且该减排效应在大规模企业、非战略性行业与财政分权水平较高的样本中表现更为突出。机制检验发现,国有资本入驻既可以通过放松企业融资约束与提高企业风险承担能力的方式促进民营企业技术创新,还可以通过将自身所承担的政策性社会目标融入民营企业中,以强化民企的社会责任意识,最终在“技术创新效应”和“社会责任效应”共同驱动下实现污染减排。特别的,虽然国有资本入驻不利于提升企业生产率,但国有资本入驻引致的“技术创新效应”有助于推动民企实现生产效率与绿色化的兼容发展。本研究为完善企业创新激励机制、优化环境治理与实现发展方式绿色转型提供新的视角和动力。

“双碳”目标下低碳农业技术发展应用条件评价及路径研究

“双碳”目标下,科学评估筛选适宜不同地域的农业减排固碳技术,并因地制宜制定低碳农业技术路径具有重要的现实意义.综合采取德尔菲法、层次分析法、多因素综合评价模型进行评价表明,种植、养殖、能源消耗3个方面42项技术中发展应用条件综合水平位于3≥Z≥2.5、 2.5>Z≥2、 2>Z≥1等3个区间的比重分别为16.67%,61.90%,21.43%,大部分技术在重庆具有较好的综合推广应用条件,其中种植方面最好;重庆低碳农业发展可采取分区分级思路,根据农业生产特点按粮食主产区、养殖集中区、生态脆弱区分区推进“双增双减”“稳能减排”“提能固碳”综合技术路径,根据技术发展应用条件水平分级优先推广位于3≥Z≥2.5区间的7项技术,以及位于2.5>Z≥2区间的26项技术.最后提出加快低碳农业技术的创新步伐、推广应用、发展环境建设等对策建议.

绿色技术创新对我国碳减排的影响——基于省级区域面板数据的实证分析

为了早日实现“碳达峰碳中和目标”,我国提出要建立健全绿色低碳循环发展的经济体系,而绿色技术创新是推动绿色高质量发展的关键核心,也是解决我国现实生态环境问题的重要支撑。为了研究绿色技术创新对地区碳减排的影响机制,文章基于我国30个省份2011-2020年的面板数据构建固定效应模型,并检验了能源利用率的中介机制和地方政府竞争的调节作用。研究发现,绿色技术创新可以显著促进碳减排,但这一促进作用在我国东部地区最显著,而在中部地区和西部地区不显著;进一步研究发现,绿色技术创新可以通过提高能源利用率促进碳减排,但地方政府竞争对绿色技术创新的促进作用起到负向调节作用。本研究为提高我国绿色技术创新能力、助力“双碳目标”的实现以及促进地方政府有序竞争提供了理论支撑和对策建议。

低碳技术发展产业链风险评估

“双碳”目标下,低碳技术将迎来大规模发展,传统技术被加速替代,会对产业链相关行业原材料、资金、劳动力需求以及污染物排放等产生直接影响。因此,亟须提前评估低碳技术发展可能引发的关键要素失衡以及部分行业环境影响攀升风险,以避免威胁产业链安全,制约“双碳”目标实现。为此,选取未来有望大规模普及的电解水制氢、电化学储能、低碳发电技术、电弧炉炼钢技术及多通道燃煤等10类低碳技术作为研究对象,评估2024—2030年各项技术大规模普及对产业链相关行业原材料、资金、劳动力需求和污染物排放的综合影响,识别潜在风险。结果表明:钴、铜、镍、锂、锰等关键矿产资源对外依存度高且未来需求增长快,面临短缺风险相对更大;发展光伏发电技术对资金的需求最大;电化学储能技术普及引致的劳动力需求增长最快;关键低碳技术产业链上游的电气机械和器材制造业将面临严峻的资金和劳动力供给不足风险;煤炭采选业将面临一定的劳动力过剩风险;金属矿采选业将面临较大的环境污染上升风险。并进一步针对技术、组件、上中下游行业可能面临的风险提出了应对策略。

基于声发射和DIC的金属材料氢脆性能测试实验

该实验针对天然气掺氢管道混输过程中产生的临氢金属氢脆问题,以X80管线钢为对象,采用声发射与数字图像相关(DIC)技术相结合的方法实现氢脆性能的动态测试。实验设计为对材料进行充氢后拉伸,采用电化学充氢法充氢,并设置4种不同充氢时间。拉伸过程中通过DIC技术测量并计算静态氢脆性能参数和氢脆敏感系数,同时利用等效应变云图和声发射计数峰值时域分布的变化规律作为氢脆性能的动态参量,进而建立一套完整的金属氢脆性能动态测试系统。该实验适合作为学生研究型教学实验,有助于培养学生的科研能力和创新意识。

人工智能技术创新对区域碳排放的影响——机制识别与回弹效应

基于2011—2021年中国省份面板数据,多维度实证检验人工智能技术创新对区域碳排放的影响。结果显示,人工智能技术创新显著降低了碳排放强度,这一结论在进行一系列内生性、稳健性检验后仍然成立。机制分析表明,人工智能技术创新主要通过改进能源效率间接促进碳减排,产业结构高级化、市场化水平与要素资源错配水平是影响人工智能技术创新能效提升的关键因素。区域异质性分析表明,人工智能技术创新仅在东部地区对碳排放产生了显著的抑制作用,中西部地区并未产生明显的碳减排效应,反而加速了西部地区的碳排放。空间计量分析表明,人工智能技术创新不仅可以降低本地碳排放强度,还可以降低邻近地区的碳排放强度,有助于形成区域绿色创新协调发展的空间格局。另外,人工智能技术创新对碳排放的影响也存在着明显的回弹效应。研究结论为助力“双碳”目标提供可行路径,也为各地政府部门积极谋划推进人工智能技术创新方案提供新的经验证据。