An Integrated Analysis on the Synergistic Reduction of Carbon and Pollution Emissions from China’s Iron and Steel Industry

Decarbonization and decontamination of the iron and steel industry(ISI),which contributes up to 15%to anthropogenic CO_(2) emissions(or carbon emissions)and significant proportions of air and water pollutant emissions in China,are challenged by the huge demand for steel.Carbon and pollutants often share common emission sources,indicating that emission reduction could be achieved synergistically.Here,we explored the inherent potential of measures to adjust feedstock composition and technological structure and to control the size of the ISI to achieve carbon emission reduction(CER)and pollution emission reduction(PER).We investigated five typical pollutants in this study,namely,petroleum hydrocarbon pollutants and chemical oxygen demand in wastewater,particulate matter,SO_(2),and NO_(x) in off gases,and examined synergies between CER and PER by employing cross elasticity for the period between 2022 and 2035.The results suggest that a reduction of 8.7%-11.7%in carbon emissions and 20%-31%in pollution emissions(except for particulate matter emissions)could be achieved by 2025 under a high steel scrap ratio(SSR)scenario.Here,the SSR and electric arc furnace(EAF)ratio serve critical roles in enhancing synergies between CER and PER(which vary with the type of pollutant).However,subject to a limited volume of steel scrap,a focused increase in the EAF ratio with neglection of the available supply of steel scrap to EAF facilities would lead to an increase carbon and pollution emissions.Although CER can be achieved through SSR and EAF ratio optimization,only when the crude steel production growth rate remains below 2.2%can these optimization measures maintain the emissions in 2030 at a similar level to that in 2021.Therefore,the synergistic effects between PER and CER should be considered when formulating a development route for the ISI in the future.

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.

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.

Review on coal-based reduction and magnetic separation for refractory iron-bearing resources

The application of coal-based reduction in the efficient recovery of iron from refractory iron-bearing resources is comprehensively reviewed.Currently,the development and beneficiation of refractory iron-bearing resources have attracted increasing attention.However,the effect of iron recovery by traditional beneficiation methods is unacceptable.Coal-based reduction followed by magnetic separation is proposed,which adopts coal as the reductant to reduce iron oxides to metallic iron below the melting temperature.The metallic iron particles aggregate and grow,and the particle size continuously increases to be suitable for magnetic separation.The optimization and application of coal-based reduction have been abundantly researched.A detailed literature study on coal-based reduction is performed from the perspectives of thermodynamics,reduction kinetics,growth of metallic iron particles,additives,and application.The coal-based reduction industrial equipment can be developed based on the existing pyrometallurgical equipments,rotary hearth furnace and rotary kiln,which are introduced briefly.However,coal-based reduction currently mainly adopts coal as a reductant and fuel,which may result in high levels of carbon dioxide emissions,energy consumption,and pollution.Technological innovation aiming at decreasing carbon dioxide emissions is a new trend of green and sustainable development of the steel industry.Therefore,the substitution of coal with clean energy(hydrogen,biomass,etc.)for iron oxide reduction shows promise in the future.

Technical and Economic Index System for CO_2 Emission Reduction in China's Power Industry

The main technic and economic indices for carbon dioxide emission reduction of Chinese electric power industry are designed systematically in this paper.According to quantitative calculation and influential factor analysis on the carbon dioxide emission reduction of the industry from 1978 to 2009,the author estimates and calculates the relevant indices during the 12 th Five-Year Plan period and in 2020.Finally the author analyzes the relationship and difference between the conventional technical and economic indices for electric power planning and the new index system for the low carbon economy development.

Tracking Transfer of Carbon Dioxide Emissions to Countries along the Silk Roads Through Global Value Chains

The Belt and Road Initiative(BRI)has aroused rich discussions about the possible increase in carbon dioxide emission under the arduous global carbon dioxide emission reduction task.Adopting the methods of input-output technique and complex network ana-lysis,we first construct a fairer method to trace carbon dioxide emission transfer based on global value chains,then trace the source of carbon dioxide emission transfer to the Silk Roads countries with a long-term multiple regional input-output database.We find that,first,after the proposal of the BRI,the total direct carbon dioxide emissions of the Silk Roads countries and China’s proportion of carbon dioxide emission transfer to the other Silk Roads countries have both declined.Second,the Silk Roads countries are generally the net receivers of carbon dioxide emission transfer,and the inflow is mainly distributed in Southeast Asian countries and core countries in other sub-regions.Then,the transfer of carbon dioxide emission accepted by the Silk Roads countries comes mostly from large developing countries,such as China,Russia,and India,and developed countries,such as the United States,Japan,and Germany.The products are mainly concentrated in energy and chemical industries,as well as heavy industries,such as mining and quarrying,and metal products.We suggest that,due to the high degree of spatial and industrial concentrations of carbon dioxide emission transfer,it is necessary to make targeted policies for these countries and industries to reduce these transfers.

Enhanced electrocatalytic activity of iron amino porphyrins using a flow cell for reduction of CO_(2) to CO

The flexibility of molecular catalysts is highly coveted for the electrochemical reduction of carbon dioxide(CO_(2)) to carbon monoxide(CO) in both homogeneous and heterogeneous systems.While the electrocatalytic activity of molecular catalysts has been widely studied in H-cells;their less studied capabilities in more efficient flow cell reactors have the potential to rival that of heterogeneous catalysts.In this work,a comparative study of amino functionalized iron-tetraphenylporphyrins(amino-Fe-TPPs) immobilized onto carbonaceous materials in both H-cells and flow cells was conducted to selectively reduce CO_(2) to CO.In a flow cell set up operating in alkaline media,the resulting hybrid catalyst exhibits 87% faradaic efficiency(FE) with extraordinary current density(j) of 119 mA/cm^(2) and turnover frequency(TOF) of 14 s^(-1) at-1.0 V vs.RHE.This remarkable catalytic activity was achieved through thoughtful combination of molecular and flow cell design that provides an effective strategy for future immobilized heterogeneous approaches toward CO_(2) reduction reactions(CO_(2) RRs).

Investigating the Impact of Capacity Utilization on Carbon Dioxide Emission: Evidence from China's Iron and Steel Industry

In recent years, China’s industrialization and urbanization have deepened, and the economy has grown considerably. But at the same time, they have also brought about many environmental problems. As a pillar of the national economy, the iron and steel(IS) industry is one of the most emitting and energy-consuming sub-sectors of the industrial sector. It is also one of the industries with the most severe overcapacity problem in China. In this paper, we explore the impact of capacity utilization on carbon dioxide emission based on panel data of China’s iron and steel industry from 2005 to 2014. We also tested the heterogeneity in different regions and different sub-samples. Results show that capacity utilization and carbon dioxide emission are positively correlated. However, the impact of capacity utilization on carbon dioxide emission differs when considering regional heterogeneity. Results in all three regions show a positive relationship between capacity utilization and carbon dioxide emission,but the impact intensity is strongest in the western region, followed by the eastern and central regions.Moreover, capacity utilization impacts carbon dioxide emission by influencing firm numbers in the iron and steel industry and energy consumption. Further analysis shows that there exists a threshold effect in different stages of energy consumption and energy structure. Finally, some findings and practical policy recommendations are provided.

Carbon Dioxide Control-Technology for the Future

The world is experiencing global climate change, and most scientists attribute it to the accumulation in the atmosphere of carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons. Because of its enormous emission rate, carbon dioxide （CO2） is the main culprit. Almost all the anthropogenic CO2 emissions come from the burning of fossil fuels for electricity, heat, and transportation. Emissions of COg can be reduced by conservation, increased use of renewable energy sources, and increased efficiencies in both the production of electrical power and the transportation sector. Capture of CO2 can be accomplished with wet scrubbing, dry sorption, or biogenic fixation. After CO2 is captured, it must be transported either as a liquid or a supercritical fluid, which realistically can only be accomplished by pipeline or ship. Final disposal of CO2 will either be to underground reservoirs or to the ocean; at present, the underground option seems to be the only viable one. Various strategies and technologies involved with reduction of CO2 emissions and carbon capture and sequestration （CCS） are briefly reviewed in this paper.

Road life-cycle carbon dioxide emissions and emission reduction technologies:A review

Carbon dioxide(CO_(2))emissions from the road sector have attracted increasing attention in current years.This paper attempted to provide a systematic review of the existing research efforts on road life-cycle CO_(2)emissions by analyzing the system’s boundary division,identifying the CO_(2)emission contributions of each life-cycle phase,listing major emission contributors,exploring related emission reduction technologies,and giving directions for future development.The research showed that the road life cycle is usually divided into five phases:material production,construction,use,maintenance and end-of-life(EOL)phases.The use phase and the initial construction stage(including material production and construction phases)contributed the most CO_(2)emissions during the road life cycle.In detail,the production of cement,asphalt and steel were the three main emission contributors in the material production phase.The pavement roughness,albedo,and concrete carbonation were the main factors affecting emissions in the use phase.In addition,emission reduction technologies such as using recycled materials and recycling techniques,lowering mixing temperature,and equipment energy substitution were commonly used to reduce emissions from material production and construction phases.The application of emerging technologies such as carbon capture and storage,carbon sink,and the use of hydrogen,solar and photovoltaic in the road sector may have emission reduction potentials and should be highlighted more in future studies.

The role of new energy in carbon neutral

Carbon dioxide is an important medium of the global carbon cycle,and has the dual properties of realizing the conversion of organic matter in the ecosystem and causing the greenhouse effect.The fixed or available carbon dioxide in the atmosphere is defined as"gray carbon",while the carbon dioxide that cannot be fixed or used and remains in the atmosphere is called"black carbon".Carbon neutral is the consensus of human development,but its implementation still faces many challenges in politics,resources,technology,market,and energy structure,etc.It is proposed that carbon replacement,carbon emission reduction,carbon sequestration,and carbon cycle are the four main approaches to achieve carbon neutral,among which carbon replacement is the backbone.New energy has become the leading role of the third energy conversion and will dominate carbon neutral in the future.Nowadays,solar energy,wind energy,hydropower,nuclear energy and hydrogen energy are the main forces of new energy,helping the power sector to achieve low carbon emissions."Green hydrogen"is the reserve force of new energy,helping further reduce carbon emissions in industrial and transportation fields.Artificial carbon conversion technology is a bridge connecting new energy and fossil energy,effectively reducing the carbon emissions of fossil energy.It is predicted that the peak value of China’s carbon dioxide emissions will reach 110×10^(8) t in 2030.The study predicts that China’s carbon emissions will drop to 22×10^(8) t,33×10^(8) t and 44×10^(8) t,respectively,in 2060 according to three scenarios of high,medium,and low levels.To realize carbon neutral in China,seven implementation suggestions have been put forward to build a new"three small and one large"energy structure in China and promote the realization of China’s energy independence strategy.

Low-carbon transition of iron and steel industry in China:Carbon intensity, economic growth and policy intervention

As the biggest iron and steel producer in the world and one of the highest CO2 emission sectors, China’s iron and steel industry is undergoing a low-carbon transition accompanied by remarkable technological progress and investment adjustment, in response to the macroeconomic climate and policy intervention. Many drivers of the CO2 emissions of the iron and steel industry have been explored, but the relationships between CO2 abatement,investment and technological expenditure, and their connections with the economic growth and governmental policies in China, have not been conjointly and empirically examined. We proposed a concise conceptual model and an econometric model to investigate this crucial question. The results of regression, Granger causality test and impulse response analysis indicated that technological expenditure can significantly reduce CO2 emissions, and that investment expansion showed a negative impact on CO2 emission reduction. It was also argued with empirical evidence that a good economic situation favored CO2 abatement in China’s iron and steel industry, while achieving CO2 emission reduction in this industrial sector did not necessarily threaten economic growth.This shed light on the dispute over balancing emission cutting and economic growth.Regarding the policy aspects, the year 2000 was found to be an important turning point for policy evolution and the development of the iron and steel industry in China. The subsequent command and control policies had a significant, positive effect on CO2 abatement.

Mechanism of protective film formation during CO_2 corrosion of X65 pipeline steel

Electrochemical techniques, X-ray diffraction （XRD）, and scanning electron microscopy （SEM） were applied to study the corrosion behaviors of X65 steel in static solution with carbon dioxide （CO2） at 65℃. The results show that iron carbonate （FeCO3） deposits on the steel surface as a corrosion product scale. This iron carbonate scale acts as a barrier to CO2 corrosion, and can reduce the general corrosion rate. The protection ability of the scale is closely related to the scale morphological characteristics.

Co-thermal in-situ reduction of inorganic carbonates to reduce carbon-dioxide emission

Thermal decomposition of inorganic metal carbonates is the main path to prepare metal oxides;nonetheless,it is always accompanied by the emission of large amounts of CO_(2) as one of the gas products.This study reports a concept of co-thermal insitu reduction of inorganic carbonates by using the energy released by carbonate decomposition under pure hydrogen atmosphere,which reduces the decarboxylation temperature and significantly inhibits the CO_(2) emissions.A combination of hydrogen–deuterium exchange,isotope experiment,and density functional theory calculations demonstrates that the CO results from the selective cleavage of Ca–O bonds at the surface of CaCO_(3) via the direct hydrogenation mechanism at relatively low temperature.However,it undergoes the reverse water–gas shift reaction path at high temperature,i.e.,CO being produced by the reduction of CO_(2) released by the decomposition of carbonates.This study sheds light on the potential of green hydrogen technology for inorganic carbonate valorization toward high value-added products,which can facilitate the large-scale industrial applications.

Wet Soil Redox Chemistry as Affected by Organic Matter and Nitrate

Wet soil microcosms were established to determine effects of organic matter and nitrate additions on microbial respiration and redox potentials. Organic matter (1%) and nitrate (100 ppm and 200 ppm) treatments were applied in factorial combination. Soil pH, redox potential, and CO2 emissions were measured. Data were analyzed by ANOVA for repeated measures and separately by sampling day. Addition of organic matter significantly (P 0.05) and consistently increased CO2 emissions and decreased redox potentials. On Day 42 nitrate significantly (P 0.05) increased redox values. This study indicates a tendency for organic matter to decrease soil redox potential both in absolute terms and relative to the suboxic-anoxic boundary. Our findings portend that additions of organic matter may quickly and markedly decrease soil redox potentials and increase CO2 emissions in wetlands, whereas additions of nitrate may have complex and sporadic effects on redox potentials.

长三角工业减污降碳时空演变及其影响因素研究

工业领域是我国推行减污降碳协同增效的重点领域,探究工业领域减污降碳的时空特征及影响因素,对实现减污降碳协同增效总目标具有重要现实意义.本文以长三角地区41个设区市为研究对象,综合运用耦合协调度模型、空间自相关、时空地理加权回归、地理探测器等方法,对2010−2020年长三角地区工业减污降碳协同效应的时空演变特征及影响因素展开分析,因地制宜地提出工业减污降碳协同推进建议.结果表明:①2010−2020年,长三角地区41个设区市的工业大气污染物排放量平均值大幅下降,工业二氧化碳排放量缓慢增长,长三角地区工业减污降碳协同效应总体处于上升优化态势,工业减污降碳协同效应等级由失调衰退类提至过渡发展类.②2010−2020年,长三角地区工业减污降碳协同效应在空间格局上呈中部高、南北低以及东部高、西部低的分布格局,时空变动上工业减污降碳协同效应高值范围由上海、苏州等长江入海口地区向西转移至南京、无锡、苏州等长江下游地区,其空间集聚特征呈现出集聚−离散−集聚的变化趋势.③规模以上工业总产值、规模以上工业增加值占GDP比重、人均GDP、城镇化率等是影响长三角地区工业减污降碳协同效应的主要因素,对大部分区域产生显著的正向影响,其影响程度存在时空异质性,双因子交叉具有显著的增强作用.研究显示,长三角地区工业减污降碳协同效应存在显著的优化趋势和空间差异,受产业规模结构影响较大,亟需从统筹优化减污降碳协同目标、加强重点区域协同控制、加快工业行业绿色发展等方面协同推进.

Industrial Feasiblity of Direct Methane Conversion to Hydrocarbons over Fe-Based Fischer Tropsch Catalyst

Recently, as a direct consequence of the dwindling world oil reserves and the growing awareness of the environmental problems associated with the use of coal as energy source, there is growing interest in cheaper, abundant and cleaner burning methane. The Gas-to-Liquid technology offers perhaps the most attractive routes for the exploitation of the world huge and growing natural gas resources. Using this process the erstwhile stranded gas is converted to premium grade liquid fuels and chemicals that are easily transported. However, a widespread application of the GTL process is being hampered by economical and technical challenges. The high cost of synthesis gas, for instance, weighs heavily on the economics and competitiveness of the process limiting its wider application. This work presented a modified Gas-to-Liquid process that eliminates the costly synthesis gas production step. The proposed process utilized an alternative pathway for methane activation via the production of chloromethane derivatives which are then converted to hydrocarbons. It established that hydrocarbons mainly olefins can be economically produced from di- and tri-chloro- methanes over a typical iron-based Fischer Tropsch catalysts in a moving bed reactor at industrially relevant conditions. Some of the attractions of the proposed process include a) the elimination of the costly air separation plant requirement b) high process selectivity and c) significant reduction of carbon dioxide emissions thereby saving on feedstock loss and the costly CO2 removal and isolation processes.

钢铁行业二氧化碳捕集技术研究及应用进展

钢铁行业碳减排对我国实现双碳目标具有重要意义,也是国家实现碳中和承诺的主战场之一。系统综述了钢铁行业碳捕集技术的研究及应用进展,总结了钢铁行业碳排放特征,其中高炉炼铁工序是钢铁行业碳排放量最高的工序,其CO_(2)直接排放主要来源于高炉热风炉,占比高达30%左右。钢铁行业的碳捕集技术主要包括有机胺吸收技术、氨水吸收技术、变压吸附技术和钢渣矿化技术,但目前应用案例较少且规模普遍偏小。此外,还对新型有机胺吸收剂、改性分子筛材料等碳捕集材料的研究进展进行了系统总结。未来的研究应重点关注高炉煤气以及高炉热风炉烟气中的CO_(2)捕集,加强对相变吸收体系和催化辅助再生体系的研究,以解决吸收剂分相性能和黏度之间的平衡问题及催化剂稳定性问题,促进两者耦合应用;加强CO_(2)捕集利用一体化技术的研究,重点关注烟气-钢渣直接矿化技术和吸收-矿化一体化技术。

我国大豆油脂加工业碳排放测算与减排分析——以某大豆油脂加工企业为例

为服务于碳减排国家战略,以某典型大豆油脂加工企业为研究对象,明确碳排放计算边界,梳理能耗指标变化,采用碳排放系数法确定该企业二氧化碳排放量,推算2015—2022年我国大豆油脂加工业二氧化碳排放量,并提出碳减排措施。结果表明:2020年前该企业二氧化碳排放量为0.111t/t(以大豆计),2020年后经工艺改进其二氧化碳排放量为0.097t/t(以大豆计);大豆油脂加工业二氧化碳排放量在2017年达到峰值,为1095万t;如加工能耗稳定下降,虽然2030年大豆消费量达到最大值(1.26亿t),大豆油脂加工业二氧化碳排放量仍在2017年达峰;蒸汽消耗和电耗是影响油脂加工碳排放的主要因素。为推动碳减排目标实现,大豆油脂加工业碳减排路径主要是通过持续管理和工艺改进,降低蒸汽用量和电耗。

钢铁行业大气污染治理科技发展分析与展望

钢铁行业是我国工业领域重要的大气污染排放源之一,钢铁行业的大气污染治理是降低重点行业污染排放、打好污染防治攻坚战的重中之重。近年来,我国在钢铁行业大气污染治理方面取得了显著成果。总结了我国“十一五”以来钢铁行业污染防治科技工作的部署,并梳理分析了钢铁行业大气污染治理技术发展的阶段。基于末端治理、源头减排和过程控制、全过程耦合控制三个方面技术发展现状,剖析了当前我国钢铁行业在多污染物协同深度减排和实现超低排放面临的形势和问题。最后,面向“十四五”时期,聚焦碳达峰碳中和目标,提出了相关建议,旨在深化大气污染防治科技工作,为建设“美丽中国”和实现“双碳”目标提供关键科技支撑。在未来的发展中,我们有理由相信,在全社会的共同努力下,钢铁行业将迎来更加清洁、高效和可持续的发展。