Carbon emissions in China's steel industry from a life cycle perspective: Carbon footprint insights.

China is the most important steel producer in the world, and its steel industry is one of the most carbon-intensive industries in China. Consequently, research on carbon emissions from the steel industry is crucial for China to achieve carbon neutrality and meet its sustainable global development goals. We constructed a carbon dioxide (CO2) emission model for China's iron and steel industry from a life cycle perspective, conducted an empirical analysis based on data from 2019, and calculated the CO2 emissions of the industry throughout its life cycle. Key emission reduction factors were identified using sensitivity analysis. The results demonstrated that the CO2 emission intensity of the steel industry was 2.33 ton CO2/ton, and the production and manufacturing stages were the main sources of CO2 emissions, accounting for 89.84% of the total steel life-cycle emissions. Notably, fossil fuel combustion had the highest sensitivity to steel CO2 emissions, with a sensitivity coefficient of 0.68, reducing the amount of fossil fuel combustion by 20% and carbon emissions by 13.60%. The sensitivities of power structure optimization and scrap consumption were similar, while that of the transportation structure adjustment was the lowest, with a sensitivity coefficient of less than 0.1. Given the current strategic goals of peak carbon and carbon neutrality, it is in the best interest of the Chinese government to actively promote energy-saving and low-carbon technologies, increase the ratio of scrap steel to steelmaking, and build a new power system.

Quantifying China's iron and steel industry's CO2 emissions and environmental health burdens: A pathway to sustainable transformation.

Assessing the iron and steel industry's (ISI) impact on climate change and environmental health is vital, particularly in China, where this sector significantly influences air quality and CO2 emissions. There is a lack of comprehensive analyses that consider the environmental and health burdens of manufacturing processes for ISI enterprises. Here, we present an integrated emission inventory that encompasses air pollutants and CO2 emissions from 811 ISI enterprises and five key manufacturing processes in 2020. Our analysis shows that sintering is the primary source of air pollution in the ISI. It contributes 71% of SO2, 73% of NO x , and 54% of PM2.5 emissions. On the other hand, 81% of total CO2 emissions come from blast furnaces. Significantly, the contributions of ISI have resulted in an increase of 3.6 µg m-3 in national population-weighted PM2.5 concentration, causing approximately 59,035 premature deaths in 2020. Emissions from Hebei, Jiangsu, Shandong, Shanxi, and Inner Mongolia provinces contributed to 48% of PM2.5-related deaths in China. Moreover, the transportation of air pollutants across provincial borders highlights a concerning trend of environmental health inequality. Based on the research findings, it is crucial for ISI manufacturers to prioritize the removal of outdated production capacities and adopt energy-efficient and advanced techniques, along with ultra-low emission technologies. This is particularly important for those manufacturers with substantial environmental footprints. These transformative actions are essential in mitigating the environmental and health impacts in the affected regions.

Spillover effects of structure-adjustment pollution reduction measures in China's iron and steel industry.

The iron and steel industry (ISI) is a significant source of sulfur dioxide and particulate matter pollution in China. Existing research on regional environmental regulation or ISI emission reduction strategies tends to overlook spillover effects and the enterprise perspective. During the heating season, production limitations in ISI are potential policy measures for achieving structural emission reductions in heavily polluted cities in China's Jing-Jin-Ji and surrounding regions. We adopt a bottom-up modeling approach, incorporating effective production time to describe enterprise behavior and establishing a quantitative trade model based on trade theory. By modeling three types of production restriction policies outlined in policy documents, we evaluate the emission reduction effects of structure-adjustment measures using the example of reduced effective production time for steel-producing enterprises in the air pollution transmission channel in the Beijing-Tianjin-Hebei area. The results indicate the following: (1) Reducing the effective production time of ISI enterprises can help decrease domestic production value and total factor productivity in pollution-intensive industries, including but not limited to ISI. It also leads to reduced emissions of various pollutants in the implementation regions. (2) Due to interprovincial trade and input-output linkages, structural reduction measures in certain regions have implications for almost all other provinces' industrial structures. Differences in initial industrial structures, factor endowments, and geographical locations contribute to varying directions and magnitudes of industrial structural changes. Pollution-intensive industries' share tends to increase higher in less developed regions. (3) Our estimated pollution reduction is smaller compared to the literature evaluating clean air policies in similar regions using top-down strategies. This discrepancy arises because we analyze a single policy tool rather than modeling industry-wide emission fluctuations from the top down. Additionally, our modeling approach allows us to examine dynamic changes in comparative advantages. The increase in production scale for certain industries in policy-affected regions partially offsets the decline in pollution emissions. These findings enhance our understanding of structure-adjustment reduction measures' role and highlight their potential advantages and limitations.

Analysis of the synergistic benefits of typical technologies for pollution reduction and carbon reduction in the iron and steel industry in the Beijing-Tianjin-Hebei region.

With its high energy consumption and pollutant emissions, the iron and steel industry is a significant source of air pollution and carbon emissions in the Beijing-Tianjin-Hebei (BTH) region. To improve air quality and reduce greenhouse gas emissions, a series of policies involving ultra-low emission, synergistic reduction of pollution, and carbon application have been implemented in the region. This study has assessed air pollutant and CO2 emission patterns in the iron and steel industry of the region by employing co-control effects coordinate system, marginal abatement cost curve, and numerical modeling, along with the synergistic benefits of typical technologies. The results have demonstrated that: (1) the intensive production activities pertinent to iron and steel enterprises has contributed greatly to the emission in Tangshan and Handan, where the sintering process is the main source of SO2, NOx, PM2.5, and CO, accounting for 64.86%, 55.15%, 29.98%, and 46.43% of the total emissions, respectively. (2) Among the typical pollution control and reduction measures, industrial restructuring and adjustment of the energy-resource structure have led to the greatest effects on emission reduction. Technologies exhibiting great potential in emission reduction and high-cost efficiency such as Blast Furnace Top Gas Recovery Turbine Unit (TRT) need to be promoted. (3) In Tangshan city with the highest level of steel production, the iron and steel production activities contributed to the concentration of 30.51% of PM2.5, 50.67% of SO2, and 42.54% of NO2 during the non-heating period. During the heating period, pollutants pertinent to the combustion of fossil energy for heating have increased, while iron and steel induced emissions have decreased to 23.7%, 34.32%, and 29.13%, respectively. By 2030, it is speculated that the contribution of the iron and steel industry to air quality will be significantly decreased as result of successful implementation of ultra-low emission policies and typical synergistic reduction technologies.

Decomposition of the site-level energy consumption and carbon dioxide emissions of the iron and steel industry.

Identifying the key factors influencing energy consumption and CO2 emissions is necessary for developing effective energy conservation and emission mitigation policies. Previous studies have focused mainly on decomposing changes in energy consumption and CO2 emissions at the national, regional, or sectoral levels, while the perspective of site-level decomposition has been neglected. To narrow this gap in research, a site-level decomposition of energy- and carbon-intensive iron and steel sites is discussed. In this work, the logarithmic mean Divisia index (LMDI) method is used to decompose the changes in the energy consumption and CO2 emissions of iron and steel sites. The results show that the production scale significantly contributes to the increase in both energy consumption and CO2 emissions, with cumulative contributions of 229.63 and 255.36%, respectively. Energy recovery and credit emissions are two key factors decreasing site-level energy consumption and CO2 emissions, with cumulative contributions to the changes in energy consumption and CO2 emissions of -158.30 and -160.45%, respectively. A decrease in energy, flux, and carbon-containing material consumption per ton of steel promotes direct emission reduction, and purchased electricity savings greatly contribute to indirect emission reduction. In addition, site products and byproducts promote an increase in credit emissions and ultimately inhibit an increase in the total CO2 emissions of iron and steel sites.

Iron and Steel Industry Emissions: A Global Analysis of Trends and Drivers.

The iron and steel industry (ISI) is important for socio-economic progress but emits greenhouse gases and air pollutants detrimental to climate and human health. Understanding its historical emission trends and drivers is crucial for future warming and pollution interventions. Here, we offer an exhaustive analysis of global ISI emissions over the past 60 years, forecasting up to 2050. We evaluate emissions of carbon dioxide and conventional and unconventional air pollutants, including heavy metals and polychlorinated dibenzodioxins and dibenzofurans. Based on this newly established inventory, we dissect the determinants of past emission trends and future trajectories. Results show varied trends for different pollutants. Specifically, PM2.5 emissions decreased consistently during the period 1970 to 2000, attributed to adoption of advanced production technologies. Conversely, NOx and SO2 began declining recently due to stringent controls in major contributors such as China, a trend expected to persist. Currently, end-of-pipe abatement technologies are key to PM2.5 reduction, whereas process modifications are central to CO2 mitigation. Projections suggest that by 2050, developing nations (excluding China) will contribute 52-54% of global ISI PM2.5 emissions, a rise from 29% in 2019. Long-term emission curtailment will necessitate the innovation and widespread adoption of new production and abatement technologies in emerging economies worldwide.

Identification of priority pollutants at an integrated iron and steel facility based on environmental and health impacts in the Yangtze River Delta region, China.

Emissions from the iron and steel industry are a major source of air pollution. To investigate the composition characteristics, estimate the secondary transformation potential, and assess the ecological risk and human health risks of air pollutants from iron and steel industry, field measurements of volatile organic compounds (VOCs) and trace metals (TMs) were conducted simultaneously from 2020 to 2022 in the Yangtze River Delta (YRD) region, China. The average mixing concentration of VOCs (Σ64VOCs) was 58.2 ppbv. Alkanes, alkenes and aromatics were the major components. Benzene and ethylene were the most abundant VOC species. In the O3 season, the calculated OH loss rates (LOH) and ozone formation potential (OFP) were 10.87 S-1 and 181.74 ppbv, respectively, which increased 39.54% and 21.51% compared to the non-O3 season. Furthermore, the O3-VOCs-NOx sensitivity indicated that O3 formation was under the VOCs-limited regime. The average concentration of total 10 trace metals (Σ10TMs) was 226.8 ng m-3, Zn, Pb and Mn were the top abundant TM species. The results also found that Se was extremely contaminated; Pb and Zn was heavily to extremely contaminated; Cu, As and Ni were moderately to heavily contaminated. For lifetime cancer risk, the cumulative carcinogenic risks were 1.84E-5 for children, 6.14E-5 for adults and 1.83E-5 for workers. The carcinogenic risks of individual chemicals cannot be ignored, especially for Cr, Ni, benzene and 1,3-butadiene. The hazard index values for workers and residents were 0.53 and 2.23, respectively, suggesting a high non-carcinogenic risks to the exposed population. These findings deepen the understanding of the pollutant character of the iron and steel industry, and provide theoretical support for policy development on O3 pollution treatment and human health in the YRD region, China. For the study area, we recommend utilizing high-quality raw coal, reducing the volatile hydrocarbon content in the sinter feed, and installing absorption device for highly reactive VOC components at the exhaust outlet.

A Facility-Level Phaseout Strategy for China's Blast Furnaces to Address Multiple Policy Objectives.

Given the urgency of addressing climate change and the declining demand for steel, it is imperative that China's iron and steel industry begin phasing out its primary production facility, the blast furnace. While there are various studies examining the decarbonization pathways for this sector and the resulting impacts, research exploring how to design decarbonization pathways that consider economic, environmental, and regional aspects equally is lacking. Moreover, it remains unclear how the individual heterogeneity of facilities affects the effectiveness of climate policies. In this study, we address the aforementioned research gaps by proposing a novel strategy that takes into account economic, carbon, water, and health factors in determining the priority for the closure of China's blast furnaces. We developed a bottom-up framework that incorporates a facility-level data set, a stock-driven dynamic material analysis, and retirement metrics with uncertain parameters to measure the multidimensional impacts of various phaseout pathways for China's blast furnaces. We have identified potential pathways that can improve environmental efficiency in multiple aspects compared with the cost-minimization pathway without impeding regional equality.

Target the neglected VOCs emission from iron and steel industry in China for air quality improvement.

Recent years have witnessed significant improvement in China's air quality. Strict environmental protection measures have led to significant decreases in sulfur dioxide (SO2), nitrogen oxides (NO x ), and particulate matter (PM) emissions since 2013. But there is no denying that the air quality in 135 cities is inferior to reaching the Ambient Air Quality Standards (GB 3095-2012) in 2020. In terms of temporal, geographic, and historical aspects, we have analyzed the potential connections between China's air quality and the iron and steel industry. The non-target volatile organic compounds (VOCs) emissions from iron and steel industry, especially from the iron ore sinter process, may be an underappreciated index imposing a negative effect on the surrounding areas of China. Therefore, we appeal the authorities to pay more attention on VOCs emission from the iron and steel industry and establish new environmental standards. And different iron steel flue gas pollutants will be eliminated concurrently with the promotion and application of new technology.

Red mud recycling by Fe and Al recovery through the hydrometallurgy method: a collaborative strategy for aluminum and iron industry.

In this work, a collaborative strategy for the aluminum and iron industry based on red mud recycling through the hydrometallurgy method was proposed. In this method, Fe3+ and Al3+ were firstly separated from the red mud by using H2SO4 as a leaching agent, which was by-produced from the sintering process of an iron and steel industry. Multiple influence factors on the leaching process were investigated, with the H2SO4 addition amount showing the strongest influence on the leaching rates of Al and Fe. The main components of the filter residue were CaSO4, TiO2, and SiO2, which could be reused as additives in the building materials. Subsequently, the final Fe recovery product was obtained through the co-precipitation, Fe/Al separation, and Fe(OH)3 calcination. In the final product, the content of Fe2O3 reached 82.87%, and the iron grade was 58.01%, meeting the requirement being raw materials for sinter production.

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 SO2 and NOx. Based on the characteristics of high NOx concentrations and the coexistence of multiple pollutants in coke oven flue gas, low-NOx 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 ultra-low 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, SO2, NOx, SO3, mercury and other pollutants, and offering technical support for the green development of the iron and steel industry.

Treatment technologies for sustainable management of wastewater from iron and steel industry - a review.

The iron and steel industries are a vital driving force for propelling the nation's economic growth. In 2019, to boost the economy and to achieve the target of five trillion economies by 2024, government of India entails investments in several steel-related sectors. However, since their inception, steel and iron industries have been coupled with extensive environmental pollution and vast water utilization. Discharged effluent from the different units of plant loaded with toxic, hazardous, and unused components which have various harmful environmental and health impacts and need treatment. In the present review, the pollutants treatment efficiency of various treatment techniques, effluent volume product quality, and various measures for sound management of wastewater are reviewed. As most conventional wastewater treatment methods are not sufficient for complete reclamation and remediation of effluent, the potential of more advanced treatment such as membrane separation and membrane bioreactors is relatively untouched. In the end, this paper concluded that the integrated system combining chemical treatment with membrane separation can ensure a worthy rate of pollutant removal. Reuse and effective management of wastewater with process intensification guarantee commercial viability and eco-friendliness.

[Pollution Characteristics and Emission Factors of PCDD/Fs from Iron and Steel Industry].

The pollution level, emission characteristics, and emission factors of PCDD/Fs from a number of steel plants were investigated in a particular province of China. The results showed that the concentration of PCDD/Fs was at a low level and decreased by 1-2 orders of magnitude compared with that in 2005-2019. In detail, the concentrations of PCDD/Fs ranged from 0.003-0.557 ng·m-3(I-TEQ), and the mean value was 0.165 ng·m-3 for the sintering process. Moreover, the concentrations of PCDD/Fs ranged from 0.006 to 0.057 ng·m-3, and the mean value was 0.025 ng·m-3 for the electric furnace process. In addition, the concentration of PCDD/Fs in the iron and steel industry from 2005 to 2020 increased first and then decreased, especially after the implementation of the new emission standard and the ultra-low emission control of conventional pollutants such as smoke, showing a significant decline. The results of fingerprint analysis showed that 2,3,7,8-TCDF was the largest congener contributing to the mass concentration, and lower chlorinated PCDFs were increased. This result differed from those of previous studies in which highly chlorinated PCDFs and PCDDs dominated, indicating that the generation source of PCDD/Fs had changed. The congener and isomer profiles of PCDD/Fs in flue gas from the sintering process were similar to those in the flue gas from the electric furnace process. Additionally, showing the characteristics of the typical high-temperature thermal process, the de novo synthesis may be the dominant mechanism of formation of PCDD/Fs in the sintering process and electric furnace process. The emission factor was 0.003-0.5 µg·t-1 (I-TEQ), and the average emission factor was (0.18±0.22) µg·t-1 for the sintering process. The emission factor was 0.04-0.5 µg·t-1, and the average emission factor was (0.27±0.23) µg·t-1 for the electric furnace process. These values were far lower than those of the standard toolkit for identification and quantification of dioxin and furan emissions released by UNEP in 2013 and the emission factors in the dioxin emission inventory of China in 2004. It is suggested that the emission factors of PCDD/Fs in the iron and steel industry of China should be studied and updated.

The impact of financial development on CO2 emissions of global iron and steel industry.

As carbon peaking and carbon neutrality have become a global consensus, more and more countries have introduced relevant policies to adapt to their own countries and formulated corresponding time roadmap. The industrial sector, especially the steel sector, which produces high levels of pollution and carbon emissions, is facing significant pressure to transform its operations to reduce CO2 emissions. Previous studies have shown the importance of financial development (FD) in environmental protection; however, the impact of FD on the CO2 emissions of the steel sector is ignored. This paper examines the impact of FD on the CO2 emissions of the iron and steel industry from a global perspective using comprehensive panel data from a total of 30 countries during the period from 1990 to 2018. Empirical results show that an improved level of FD in a given country reduces the CO2 emissions of the iron and steel industry. The mechanism analysis indicates that FD promotes the upgrading of the structure of the iron and steel industry and the reduction of the CO2 emissions by means of the three-stage least square method. Our results also show that the effect of FD on reducing the CO2 emissions of the iron and steel industry in developing countries is less than its effect in developed countries. Estimation results also show the existence of the environmental Kuznets curve hypothesis in the iron and steel industry. Finally, we discuss the policy implications of achieving carbon neutrality in the steel sector.

Industrial-environmental management in China's iron and steel industry under multiple objectives and uncertainties.

Industrial-environmental management is a multi-objective optimization problem plagued with multiple uncertainties. Most studies only optimize few objectives and often neglect these uncertainties. This study builds a 6-objective optimization problem to quantify energy conservation and emission reduction (ECER) potentials in China's iron and steel industry. First, uncertainties are simulated through 100,000-time random sampling, NSGA-II and the mean-effective objective mechanism are applied to calculate optimal solutions. Finally, a global sensitivity analysis is performed to classify uncertainty parameters based on their impacts on objectives' performance. Results show: (1) There exist significant discrepancies between objectives' performance under certainty and uncertainty. For example, the deterministic CO2 intensity is 1148 kg/t, which is 11.93% lower than its value under uncertainty. Therefore, neglecting uncertainty increases the risk of noncompliance with policy targets as they might be too strict; (2) Two critical uncertainty parameters (steel ratios and technology penetration rates) have the most severe impacts on objectives' performance, hence, reducing their fluctuation can minimize uncertainties when estimating ECER potentials; (3) By-product recycling and energy efficiency measures have good performance in all objectives, thus, should be prioritized. Moreover, from 77-strategies assessed, 11 are identified as key-strategies due to their large ECER effects, hence, should be strongly promoted.

The changes in spatial layout of steel industry in China and associated pollutant emissions: A case of SO2.

The spatial layout of the steel industry has an impact on the regional atmospheric environment. In this study, the steel industry evolution model and the driving force analysis model were combined to analyze the evolution of spatial layout of the steel industry in China and the driving factors of this evolution. In addition, the WRF-SMOKE-CMAQ model was used to analyze the spatial dynamics of SO2 emissions from the steel industry. Our analysis presents the evolution of the steel industry in China in four stages: policy-determining, resource-oriented, economic promotion and market-oriented stage. The change in the spatial layout of the Chinese steel industry resulted in a continuously decreasing trend of pollutants in temporal characteristics and a decreasing share of emissions in North China and a continuous growth in East China in spatial characteristics. Our simulation shows that, by 2025, the pollutant SO2 emission concentration will migrate to the southeast, subject to market-oriented factors.

Accidents and injuries in workers of iron and steel industry in West Bengal, India: Prevalence and associated risk factors.

This study estimates the prevalence and risk factors of accidents and injuries among iron and steel industry workers. A cross-sectional study (N = 505) was conducted from November 2019 to March 2020 in the Indian Iron and Steel Company (IISCO), Burnpur, West Bengal, India. The result shows that about 28% of workers experienced accidents and injuries in the last 12 months. The most frequent injuries reported were cuts from sharp objects (37.32%), followed by fractures and dislocation (30.28%) and burns (19.01%), upper head injury (23.24%) and arm/shoulder injury (14.08%). Non-technical education (adjusted odds ratio [AOR]: 2.52), higher exposure in risky and polluted areas (AOR: 2.85), alcohol consumption (AOR: 2.47), poor occupational health and safety knowledge (AOR: 0.65) were significantly associated with work-related injuries. Occupational health and safety knowledge and usage of safety measures must be propagated and monitored to curb accidents and injuries among iron and steel industry workers in India.

Technology innovation system analysis of decarbonisation options in the EU steel industry.

Decarbonisation of the iron and steel (I&S) industry is crucial in the efforts to meet the EU GHG emission reduction objectives in 2030 … 2050. Promoting decarbonisation in this sector will necessarily require the identification, development, and diffusion of breakthrough technologies for I&S production. This paper uses an approach inspired by the Technology Innovation System (TIS) to analyse the development of technology in the EU I&S industry and identify potential avenues of its decarbonisation. We have described key elements of the TIS, analyse the functioning of these elements and their interactions in a more general context of innovation dynamics and policy design; The focus has been put on the role of actors and the identification of the main specific blocking and inducement mechanism in the TIS to better explain its functioning. Risks and uncertainties have also been discussed. We argue that deep decarbonisation in the I&S industry is feasible but its TIS requires firm support, mostly political, to finance intensive R&D and reduce the business risk. To this end, all actors shall support more effectively the invention and implementation of new radical production technologies. The recommendations are mostly addressed to politicians although stressing the importance of collaboration of all actors.

Impact of VOCs emission from iron and steel industry on regional O3 and PM2.5 pollutions.

Iron and steel industry emission is an important industrial source of air pollution. However, little is known about the relationship between volatile organic compounds (VOCs) emitted and regional air pollution. In this study, VOCs emissions from a typical iron and steel plant in Yangtze River Delta (YRD, China) were monitored from April 2018 to March 2019. The ozone formation potential (OFP) and secondary organic aerosol (SOA) formation of VOCs were calculated to reveal the influence of VOCs emissions on regional ozone and particulate pollution, and the sensitivity analysis approach was performed to explore the qualitative and quantitative relationships between VOCs and O3, as well as VOCs and PM2.5. The VOCs concentration was 93.76 ± 266.97 ppbv during the study. The OFP was 760.08 ± 2391.90 µg m-3, and aromatics were the predominant precursors, contributing 54.05% of the total OFP. Furthermore, the SOA estimated by fractional aerosol coefficient (FAC) and time-resolved (TR) methods were 6.032 ± 13.347 µg m-3 and 0.971 ± 4.650 µg m-3, accounting for 8.65-26.39% (13.78 ± 7.46%) and 1.55-4.20% (2.22 ± 1.23%) of the PM2.5 concentrations, respectively. The results indicated that VOCs were more sensitive to O3 pollution in high pollution domains, whereas VOCs were more sensitive to PM2.5 pollution in low pollution domains. We concluded that reducing VOCs emissions might be effective in alleviating photochemical pollution episodes in areas around iron and steel industry, and the haze pollution occurred in these regions may be caused by the primary emission of PM, and the contribution of SOA was relatively small.

Environmental efficiency evaluation of China's iron and steel industry: A process-level data envelopment analysis.

To resolve the increasingly higher energy and environmental pressures, the evaluation of environmental efficiency in China's iron and steel industry is essential for identifying a precise energy conservation and emission reduction path. However, current studies have only focused on the efficiency evaluation in national, regional, or enterprise level, lacking the analysis of different processes. Therefore, the objective of this research is to conduct a process-level data envelopment analysis (DEA) to evaluate the environmental efficiency of China's iron and steel industry. Totally, 54 enterprises are contained, as the input-output structure of 5 processes: sintering, coking, ironmaking, steelmaking, and steel rolling are set specifically in this study. In addition, to compare the effects to the efficiency results of different DEA methods, Banker, Charnes & Cooper (BCC) model, Slack-based Measure (SBM) model, and Bootstrap-DEA methods are adopted. Finally, a regression model is used to investigate the key environmental protection strategies influencing the environmental efficiency. The results show that: (1) Within different methods, the average efficiency scores from SBM model are lower than the ones from BCC model, and the Bootstrap-DEA method also has a negative modification. (2) Regional efficiency difference exists, as the enterprises in South China perform best in sintering and coking processes but have the lowest overall efficiency scores. (3) Most enterprises have one or more short board processes. 12 enterprises are the enterprises with individual low environmental efficiency process, while other 25 are the enterprises with imbalanced environmental performances. (4) The coefficient factor between environmental protection investment and the efficiency scores are positive, but the factors of proportion of environmental protection staffs, and whether the enterprise has environmental protection research are negative. In sum, this study is hoped to contribute to formulating more precise environmental management measures in China's iron and steel industry.