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.

Exploration of Market Mechanism on Controlling Air Pollution and Carbon Emissions in China

Based on increasingly grim situation of carbon emissions in China,air pollution control and carbon emission reduction are very important. Therefore,combining with China’s specific national conditions,we should explore the market mechanisms to control air pollution and reduce carbon emissions in China. The achievement of the carbon emission reduction purpose needs to establish the carbon trade market based on intensity emission reduction and suitable for China’s national conditions. By setting the cross-industry,cross-region and cross-time carbon trade scenarios in China,this paper tries to study the market mechanism of carbon intensity trade among industries and regions and based on carbon finance mechanism.

Exploration and Practice of Precision Emission Reduction Monitoring System in Air Pollution Prevention and Control in a District of Tianjin

At present,China’s atmospheric environmental protection work has achieved initial results,but environmental protection is facing increasing pressure,and the environmental situation is still not optimistic.In response to the call of the state,efforts have been intensified in environmental protection and ecological civilization construction,and supply-side structural reform has been actively promoted,and the Implementation Plan for Tianjin’s Comprehensive Discharge of Industrial Pollution Sources to Meet Standards has been promoted.When the total amount of pollutants discharged in key areas far exceeds the environmental capacity,regional heavy pollution weather will still occur once adverse meteorological conditions are encountered.In accordance with the Law of the People’s Republic of China on the Prevention and Control of Atmospheric Pollution,when the deterioration of air quality to a certain extent,to protect public health,key gas related industries should carry out emergency emission reduction in accordance with the local emergency plan while the local government starts the emergency response of heavy pollution weather.Direct economic loss of emergency response to heavy pollution weather is enormous.On the basis of meeting the total amount of emissions required by the state,the project aims to achieve the effect of"emission reduction and production increase"by precise emission reduction according to local characteristics.

Energy Saving and Emission Reduction Estimations of Electrified Railways in China

Based on the annual production data collected by the Statistic Center of the Ministry of Railways of the People＇s Republic of China, we calculated the energy saving and direct emission reductions of CO2, soot, SO2, CO, NOx and CnHm of electrified railways, and analyzed their dynamic characteristics during the period of 1975 2007. The results show that during this period, the annual mean values of energy saving is 1.23×10^6 tce, and direct emission reduction of CO2, soot, SO2, CO, NOx and CnHm are 4.267×10^6 t, 20.5×10^3 t, 3.0×10^3 t, 9.6×10^3 t, 67.9×10^3 t, and 6.9×10^3 t per year, respectively. The annual average increasing rates of energy saving is 139×10^3 tce, and direct emission reduction of CO2, soot, SO2, CO, NOx and CnHm are 483×10^3 t, 2.3×10^3 t, 0.34×10^3 t, 1.1×10^3 t, 7.7 ×10^3 t and 0.78×10^3 t per year, respectively. The electrified railways have played an important role in decreasing the energy consumption and air pollutant emissions of China＇s railway system. The results of this study could provide some reference knowledge for future reductions of energy consumption and waste gas emission in China＇s railway transportation.

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.

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.

Emission of Combustible Gases at Traffic and Practising Waste Dumpsite in Freetown, Sierra Leone: A Pilot Study

An assessment of the emission of combustible gases in developing countries requires reliable analytical realtime monitors that can rapidly screen them with minimal handling. Considering the expensive nature of monitoring environmental pollutants, chemical sensors are expected to play a pivotal role in measuring and recording environmental data. The Drager X am 5000 was used to report emission levels of combustible gases in this study, namely;nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) at traffic and practising waste dumpsite in Freetown, the main city of Sierra Leone. Hourly average values for the three pollutants were recorded in the morning, afternoon and evening periods, respectively. The range of values were 18 - 76 ppb for NO2, 211 - 506 ppb for SO2 and 11 - 14 ppm for CO at traffic site;and 6 - 16 ppb for NO2, 118 - 276 ppb for SO2 and 8 - 15 ppm for CO at the dumpsite, respectively. There were significantly high hourly variations for NO2 and SO2 at the traffic site and for CO and SO2 at the dumpsite. Evidence of peak values showed emission levels that were considered dangerous for human exposure. This pilot study revealed that combustible gases released in certain areas of the capital city are a concern for both public health officials and environmental advocates.

Asthma Hospital Admissions and Ambient Air Pollutant Concentrations in New York City

Air pollution is considered a risk factor for asthma. In this paper, we analyze the association between daily hospital admissions for asthma and ambient air pollution concentrations in four New York City counties. Negative binomial regression is used to model the association between daily asthma hospital admissions and ambient air pollution concentrations. Potential confounding factors such as heat index, day of week, holidays, yearly population changes, and seasonal and long-term trends are controlled for in the models. Nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) show the most consistent statistically significant associations with daily hospitalizations for asthma during the entire period (1996-2000). The associations are stronger for children (0 - 17 years) than for adults (18 - 64 years). Relative risks (RR) for the inter-quartile range (IQR) of same day 24-hour average pollutant concentration and asthma hospitalizations for children for the four county hospitalization totals were: NO2 (IQR = 0.011 ppm, RR = 1.017, 95% CI = 1.001, 1.034), SO2 (IQR = 0.008 ppm, RR = 1.023, 95% CI = 1.004, 1.042), CO (IQR = 0.232 ppm, RR = 1.014, 95% CI = 1.003, 1.025). In the case of ozone (O3) and particulate matter (PM2.5) statistically significant associations were found for daily one-hour maxima values and children’s asthma hospitalization in models that used lagged values for air pollution concentrations. Five-day weighted average lag models resulted in these estimates: O3 (one-hour maxima) (IQR = 0.025 ppm, RR = 1.049, 95% CI = 1.002, 1.098), PM2.5 (one-hour maxima) (IQR = 16.679 μg/m3, RR = 1.055, 95% CI = 1.008, 1.103). In addition, seasonal variations were also explored for PM2.5 and statistically significant associations with daily hospital admissions for asthma were found during the colder months (November-March) of the year. Important differences in pollution effects were found across pollutants, counties, and age groups. The results for PM2.5 suggest that the composition of PM is important to this health outcome, since the major sources of NYC PM differ between winter and summer months.

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.

Elevated CO2 Effects on Lichen Frequencies and Diversity Distributions in Free-Air CO2 Enrichment (FACE) Station

Carbon dioxides (CO2) concentration has become much higher every year and this has already become the global issue. Lichen is a symbiotic organism that is best known as the air pollution indicator. Based on its frequency and diversity distribution, the level of pollution that has been made can be determined. This re-search was conducted in UKM Fernarium Free Air Carbon Dioxides Enrichment Station (FACE Station) with lichen frequencies and diversities observed and analyzed statistically and graphically. Seven species of li-chens were found at the sampling locations. Findings showed that there was significant relationship in lichen frequency and diversity distribution under elevated CO2 inside FACE Station with its surrounding.

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.

碳普惠制的实践检视与立法完善

碳普惠制是促进社会全面绿色转型的必要制度手段,属于生活消费端的自愿碳减排激励机制。从碳普惠的参与主体范围、行为类型、价值转化方式以及管理与监督等方面考察各省市实践发现,我国碳普惠制存在立法缺失、主体范围不清晰、行为缺乏界定标准、价值转化方式体系化不足等问题。对此,有必要构建央地协同的碳普惠法律规范体系,通过拓宽碳普惠的参与主体类型、厘清碳普惠行为的边界、建立多元互通的价值转化体系来完善碳普惠制的内部要件,并通过建立碳普惠技术研发鼓励与支持机制、拓展资金来源渠道、强化数据安全风险监控以及创新宣传推广机制等措施来健全碳普惠制的外部保障体系。

基于GTWR模型的长江经济带城市群减污降碳及其影响因素分析

以长江经济带三大城市群71个城市为研究对象,使用耦合协调度模型测度2011—2020年三大城市群减污降碳协调度,使用时空地理加权回归(GTWR)模型探究各城市群减污降碳影响因素的时空异质性。结果表明,研究期内长江经济带三大城市群减污降碳协调度整体呈上升趋势,截至2020年,三大城市群减污降碳均达到协调状态,其协调度由高到低依次为成渝城市群、长江中游城市群、长三角城市群;影响因素回归结果显示,城镇化、科技创新和环境规制能够促进减污降碳协同,人口集聚、产业结构则会抑制减污降碳,而经济发展水平、对外开放在三大城市群间表现出明显的时空异质性。基于此,从经济发展、社会进步、科技创新以及政策规制层面提出差异化的减污降碳协同治理策略,助力各城市群乃至长江经济带减污降碳目标的实现。

用于汽车行业高效泡沫的苯乙烯类热塑性弹性体

本文探讨了苯乙烯类热塑性弹性体(SEBS)在汽车行业中作为高效泡沫材料的应用。研究的起因是汽车行业对减轻车辆重量以降低温室气体排放的需求。文章通过实验分析了SEBS对聚丙烯(PP)泡沫配方的影响,以及不同SEBS结构、浓度和滑石粉浓度对泡沫机械性能的影响。研究结果表明,加入SEBS可以增强PP泡沫的抗冲击性和弹性,提高泡沫的柔韧性和降低脆性,即使在减重50%的情况下,SEBS配制的泡沫仍保持良好的机械和结构特性,有助于实现汽车轻量化,减少二氧化碳排放。

Relationship between Urban Industrial Land Use Size and Sulfur Dioxide Emissions:Evidence from 294 Cities in China

Although the relationship between the size of urban industrial land use and pollutant emissions has been widely discussed from different perspectives(e.g.,the scale and crowding effects),the results of various studies have revealed positive,negative,and combined impact relationships.However,how the expansion of urban industrial land use affects SO_(2) emissions remains unknown.We need to clarify this relationship in order to facilitate the realization of China’s pollution reduction and emission reduction goals.This study used the panel data from 294 cities spanning from 2011 to 2019 to construct a spatial econometric model.The objective was to explore the correlation between the scale of urban industrial land and sulfur dioxide emissions in China.The results show that a large scale of urban industrial land use corresponds to lower sulfur dioxide emissions per unit of industrial added value.By gaining a deeper understanding of the relationship between the scale of urban industrial land use and sulfur dioxide emissions,policymakers can further reduce pollutant emissions by rationalizing the planning of urban industrial land use and industrial layout.In addition to promoting industrial agglomeration and economies of scale in cities with extensive industrial land use,this strategy can support the development of efficient and environmentally friendly industries in areas with limited industrial land use.Optimizing the technology and encouraging the development of green industries can help reduce environmental pollution and promote sustainable urban development.

Interfacial engineering of graphitic carbon nitride(g-C_3N_4)-based metal sulfide heterojunction photocatalysts for energy conversion: A review

As one of the most appealing and attractive technologies, photocatalysis is widely used as a promising method to circumvent the environmental and energy problems. Due to its chemical stability and unique physicochemical, graphitic carbon nitride (g-C3N4) has become research hotspots in the community. However, g-C3N4 photocatalyst still suffers from many problems, resulting in unsatisfactory photocatalytic activity such as low specific surface area, high charge recombination and insufficient visible light utilization. Since 2009, g-C3N4-based heterostructures have attracted the attention of scientists worldwide for their greatly enhanced photocatalytic performance. Overall, this review summarizes the recent advances of g-C3N4-based nanocomposites modified with transition metal sulfide (TMS), including (1) preparation of pristine g-C3N4,(2) modification strategies of g-C3N4,(3) design principles of TMS-modified g-C3N4 heterostructured photocatalysts, and (4) applications in energy conversion. What is more, the characteristics and transfer mechanisms of each classification of the metal sulfide heterojunction system will be critically reviewed, spanning from the following categories:(1) Type I heterojunction,(2) Type II heterojunction,(3) p-n heterojunction,(4) Schottky junction and (5) Z-scheme heterojunction. Apart from that, the application of g-C3N4-based heterostructured photocatalysts in H2 evolution, CO2 reduction, N2 fixation and pollutant degradation will also be systematically presented. Last but not least, this review will conclude with invigorating perspectives, limitations and prospects for further advancing g-C3N4-based heterostructured photocatalysts toward practical benefits for a sustainable future.

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.

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.

Quantification of emission reduction potentials of primary air pollutants from residential solid fuel combustion by adopting cleaner fuels in China

Residential low efficient fuel burning is a major source of many air pollutants produced during incomplete combustions, and household air pollution has been identified as one of the top environmental risk factors. Here we compiled literature-reported emission factors of pollutants including carbon monoxide（CO）, total suspended particles（TSPs）, PM2.5, organic carbon（OC）,elemental carbon（EC） and polycyclic aromatic hydrocarbons（PAHs） for different household energy sources, and quantified the potential for emission reduction by clean fuel adoption. The burning of crop straws, firewood and coal chunks in residential stoves had high emissions per unit fuel mass but lower thermal efficiencies, resulting in high levels of pollution emissions per unit of useful energy, whereas pelletized biofuels and coal briquettes had lower pollutant emissions and higher thermal efficiencies. Briquetting coal may lead to 82%–88% CO, 74%–99%TSP, 73%–76% PM2.5, 64%–98% OC, 92%–99% EC and 80%–83% PAH reductions compared to raw chunk coal. Biomass pelletizing technology would achieve 88%–97% CO, 73%–87% TSP, 79%–88%PM2.5, 94%–96% OC, 91%–99% EC and 63%–96% PAH reduction compared to biomass burning. The adoption of gas fuels（i.e., liquid petroleum gas, natural gas） would achieve significant pollutant reduction, nearly 96% for targeted pollutants. The reduction is related not only to fuel change, but also to the usage of high efficiency stoves.