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Abstract: China's chemical industry has greatly altered the processes that contribute to reactive nitrogen (Nr) creation and Nr emission. However, the fluxes, fates and environmental consequences of Nr produced by the chemical industry remain poorly understood and unquantified. We report here that Nr creation and Nr emission by the chemical industry increased 47- and 37-fold from 1963 to 2015, respectively. Nr fixation in the chemical industry mainly results from the production of N fertilizer, but Nr fixation by fossil fuel combustion and chemical N products (except N fertilizer) has rapidly increased over the past 15 years. Meanwhile, the manufacture of raw chemical materials and chemical products are the main contributors to waste Nr production. Driving force analysis of Nr creation and Nr emission shows that population growth has the largest positive effect, while urbanization also has varying degrees of impact. Additionally, we propose some policy suggestions to reduce the environmental impact of Nr emissions from the chemical industry based on a brief future perspective of Nr creation and Nr emission. These findings will provide policy makers with an integrated view of Nr metabolism and environmental damage to address the significant challenges associated with reducing emissions in the chemical industry. [ABSTRACT FROM AUTHOR]

Recently, many coal-to-olefin (CTO) plants have started up in China. It is important for China to answer the following question: between coal-based ethylene and oil-based ethylene, which is the better choice? To provide a reference for policy makers and investors, this paper analyses the economic performance and the impact of future environment policy of both the CTO project and the oil-based ethylene project by a cost-benefit analysis. Quantitative analysis shows that the CTO project has a slight advantage over the oil-based ethylene project in a basic scenario when the crude oil price is above $70/bbl. However, international oil prices have a greater impact on the CTO project than the oil-based ethylene project. Thus, the CTO project has less anti-risk ability to the international oil market fluctuation than the oil-based ethylene project. What's more important is the environmental policy impact. After taking carbon trading costs and wastewater surcharge into account, the CTO project no longer has any advantage over the oil-based ethylene project. It can be seen in the foreseeable future that the CTO project will soon lose competitiveness. This indicates that the CTO project may not be consistent with sustainable development. These results suggest that from an environment perspective, policy makers and investors should be prudent about developing the CTO project. [ABSTRACT FROM AUTHOR]

Circular economy plays an essential and useful role in China in considering economic and ecological sustainability. Individual firms, as the primary implements of a circular economy, are facing many obstacles at present in aspects of resource and ecological efficiency. Therefore, this study presents a set of tools to help decision makers better solve these problems and to guide resource-based chemical industries in sustainable development. First, this study describes resource efficiency based on the SFA of a selected P-chemistry firm and identifies the key potential opportunities for improvement using analysis tools and assessment tools. Furthermore, by applying eco-design and decision tools, a firm-level, P-chemical, circular economic system is designed and constructed. A phosphorus chemical optimization model is established, and relevant successive scenarios are generated. Finally, the corresponding feasible solutions and policy recommendations are proposed to improve economic benefit, resource efficiency, waste recycling rate, and eco-efficiency. After industry design, planning, and technological progress, the total economic benefit increases dramatically, and the recycling efficiencies of accompanying resources (F, Si, I, and S) improve by different degrees. The results demonstrate that the economic benefit of phosphorus products increases by 28.5%, and P utilization efficiency correspondingly increases from 81.1% to 94.7%. The comprehensive utilization efficiency of phosphor gypsum increases to 100%, and the eco-efficiency could be improved significantly by eliminating the phosphor gypsum stack. This study demonstrates that technological progress in mineral processing and the production of associated products is the endogenic motivation to increase economic benefit and improve resource efficiency. The method proposed in this paper can be applied, duplicated, and spread not only within the P-chemical industry but also in other resource-based chemical industries. [ABSTRACT FROM AUTHOR]

Abstract: Substance flow analysis was used to develop a stock and flow model that was applied to time-series data from 1984 to 2008 to explore the correlation between change traits of anthropogenic phosphorus (P) metabolism in China and socioeconomic variables, quantify the accumulation of P in natural reservoirs and search for man-made stocks with the greatest potential for recovering P resources. The results showed that a total of 154.5 Tg P was extracted in China, but 80.5% was lost to natural water and soil, indicating the unsustainability of societal P metabolism. Urbanization, improved standards of living and population growth are responsible for the rising magnitudes of the P flows related to ore extraction, use and waste generation and the declining ratio of recycled P wastes, while inefficient small mines and corresponding restrictive policies contributed to the large fluctuation in ore extraction and waste generation in 2001–2008. Financial and policy support, combined with technological advances, strongly promoted the progress of the phosphate fertilizer industry in China, which transformed the country from a net importer into a net exporter of P materials after 2000. Three anthropogenic stocks were formed: 38.3 Tg P in agricultural soil, 19.0 Tg P in natural water and 105.3 Tg in natural soil. The last stock included 41.4 Tg P in mining wastes abandoned by small mines, which will be valuable human-induced mines for the secondary recovery of P resources in the future. Model uncertainties are analyzed, and conclusions and suggestions are presented. [Copyright &y& Elsevier]

Abstract: It is important to analyze why phosphorus metabolism is unsustainable in China''s modern industrial society. In this paper, the Substance Flow Analysis (SFA) approach is used to build different models of phosphorus metabolism for the following three periods: the prehuman period, traditional agricultural period and modern industrial period. Based on these models, the evolution process of phosphorus metabolism in China is analyzed from the viewpoint of its metabolic structure and intensity. The indices of intensity analysis involve phosphorus input, phosphorus circulation and recycling efficiency, phosphorus production and production efficiency, water phosphorus emission and water emission proportion, solid waste phosphorus output and solid waste discharge proportion. Through the analysis of the evolution process, the key factors that cause the lack of sustainability of phosphorus metabolism in China are identified, which can be summarized by four aspects: the increase of soil phosphorus accumulation, the increase of water phosphorus emission, the decrease of recycling efficiency and the decrease of production efficiency in croplands. Furthermore, the specific unsustainable processes of phosphor resources utilization in China are discussed. For these unsustainable processes, the relevant solutions for the phosphor resources crisis are given. [Copyright &y& Elsevier]

Implementing industrial symbiosis has emerged as a pivotal strategy for establishing eco-industrial parks worldwide to promote sustainable development and optimize resource utilization within industrial parks. However, the present evaluation framework for industrial symbiosis is nascent, which may hinder the ecological development of industrial parks. Therefore, to gauge industrial symbiosis efficacy and infrastructure soundness, we propose a revolutionary evaluation system that amalgamates social network analysis and ecological network analysis methodologies. Our evaluation system is meticulously customized to cater to the distinctive features and analytical requirements of eco-industrial parks and encompasses three primary facets: impact dissemination, sustainability, and resource optimization. To demonstrate the effectiveness of the proposed evaluation system, we conducted a case study of Qinghai Salt Lake industrial park. The findings reveal that the industrial symbiosis level in Qinghai Salt Lake industrial park (QSLIP) improved during 2014–2018. Nevertheless, conventional indicators are unable to pinpoint certain issues, such as deterioration in waste reutilization quality, underscoring the significance and necessity of the indicator system proposed in this study. • This study presents a innovative assessment methodology for eco-industrial parks. • A detailed examination of the Qinghai Salt Lake Industrial Park was undertaken. • A fusion of social network analysis and ecological network analysis was introduced. [ABSTRACT FROM AUTHOR]

Abstract With the rapid development of the economy and society, the number of waste household appliances in China has increased. Although the scale of China's waste household appliance industry continues to expand, the recovery rate is relatively low compared with developed countries. As waste household appliances are important recycling resources that have potential environmental risks and a high resource value, the effective recovery, recycling and utilization of these appliances are necessary to build a circular economy system, ease environmental crises and realize sustainable development in China. An agent-based model of a waste household appliance recovery system was established in this study by using complex adaptive system theory and agent-based modeling method. The simulation of agents' behavior and scenario analysis were performed using this model, and the results were analyzed to study the evolutionary trends of the industry under different policy scenarios. Based on the exploration and interpretation of the optimal scenario, policy suggestions are proposed for different parts of the system. Highlights • An agent-based model of the waste appliance recovery system is established. • Simulation of agent behavior and development trends of the system are studied. • Scenario analyses are performed under different policy conditions. • Recovery rate, pollution and policy cost are considered and balanced in the model. • Practical policy implications are proposed according to simulation results. [ABSTRACT FROM AUTHOR]

In this paper, we propose ‘material utility’ as a new concept for analyzing the influencing factors of resource productivity (RP). We demonstrate the application of this concept by empirically analyzing direct and indirect factors influencing RP. Results indicate the following: (1) RP is essentially an aggregate of the efficiency of a material's major utility for different resource categories by weight of their respective utility coefficients. (2) The direct factors influencing RP are utility coefficient (C), intensity of utility use in economic sectors (T) and economic structure (S); whereby C, T and S respectively contribute 7%, 119%, and −26% to the decline of fossil energy intensity (the inverse of RP for fossil energy) in China during the period of 1980–2010. (3) The indirect factors influencing RP are resource quality, technology and economic structure. Specifically, RP can be increased by using higher quality resources, e.g., metal ore with higher ore grade. One unit (1%) increase in research and development (R&D) expenditure intensity and percentage of tertiary industry will result in 427 US$/ton and 40 US$/ton increase in RP, respectively. This research suggests new avenues for improving the accuracy of RP as an indicator and for policy measurement for increasing RP. [ABSTRACT FROM AUTHOR]

The depletion of traditional energy sources and severe environmental pollution are hindrances in meeting the increasing energy demands of the growing global population. Solar photovoltaic (PV) technology has been widely applied in China to replace traditional energy. The factors that affect the development of the PV industry in China are complex. This research sheds light on the development process of the PV industry in China by considering the PV installed capacity as an indicator of industrial development. A quantitative evaluation method was established to assess the PV industry and its influencing factors by developing a driving force model. This model combines the methods of factor quantification and multiple regression analysis by considering demand, market, policy, technology, and enterprise factors. The results show that from 2006 to 2008, policy factors played the most important role accounting for about 50% of the total impact, and since 2009, the impacts of technology and demand factors are more significant in the PV industry from the aspects of supply and demand accounting for 36% and 32%, respectively. The future trends of PV industry are predicted based on the evolution of the influencing factors. If guided by existing policies, the PV installed capacity will stabilize at 403 GW in 2025. The emphasis on energy storage technology in the future will also significantly promote the PV industry enabling it to reach 773 GW, and thereby, reduce about 0.87 billion tonnes of carbon dioxide emissions in that year compared to that with coal-based thermal power generation. This study provides a theoretical basis for multiple factor analysis in the photovoltaic industry and a deeper understanding for policy makers to coordinate the structure of energy generation in China in the future. • A driving force model of China's photovoltaic industry is established. • Factors influencing the annual photovoltaic install capacity and their contributions are determined. • Photovoltaic industry is a good form of industrial development. • Future trends in photovoltaic industry in different scenarios are explored. • Practical policy recommendations are proposed based on factor and trend analysis. [ABSTRACT FROM AUTHOR]

The continuously increasing amount of solid waste (SW) that is being generated in China calls for environmental assessment and management strategies. However, the pattern and magnitude of the reactive nitrogen (Nr) loss associated with SW have received negligible attention. Here, we established a systematic Nr flow assessment of the generation, treatment and emissions of SW in China from 1978 to 2015. The Nr flow of SW increased by 87% during this period, with the livestock sector being the largest contributor. Composting and animal feed were the two main methods of SW treatment, accounting for more than half, whereas the two fastest growing treatments were remanufacturing and sewage treatment, which increased 13- and 62-fold, respectively. Each SW treatment method would inevitably lead to Nr emissions. Our results showed that the total Nr emissions from SW treatment increased from 8.7 Tg N yr−1 in 1978 to 18.6 Tg N yr−1 in 2015. The development of sustainable SW management requires considering both economic and environmental impacts. We use an optimization model (Solid Waste Optimization Life-Cycle Framework) and provide evidence that recycling SW resources will be an option for economic and environmental trade-offs. Image 1 • Temporal evolution in Nr flow assessment of solid waste was quantified. • Total Nr emissions from solid waste treatment increased by 114% from 1978 to 2015. • The Solid Waste Optimization Life-Cycle Framework is applied for scenario analysis. • Solid waste recycling is an option for economic and environmental trade-offs. [ABSTRACT FROM AUTHOR]

Comprehensive assessments and mitigation potential of nitrous oxide (N 2 O) emissions are particularly important, especially in China. We report that the total N 2 O emissions in China increased by 140% from 1978 to 2015, with croplands being the major emitters accounting for 35–48% of the emissions. Over the last 15 years, N 2 O emissions from industry, aquaculture and waste management have grown rapidly, while those from cropland, livestock, grassland, and human consumption have grown slowly. The spatial differences in China make the assessments of N 2 O emission patterns complex. Compared with other greenhouse gas emissions (including carbon dioxide, methane, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride) reported by the World Bank, we found that N 2 O emissions contributed approximately 9–20% (carbon dioxide equivalent) of the major greenhouse gas emissions from 1978 to 2012 in China. The growth rate of N 2 O emissions in China was 1.8 times greater than that throughout the world between 1978 and 2012. Additionally, we assessed the mitigation potential for various measures from the perspectives of production and consumption. The results show that knowledge-based nitrogen management (including the application of controlled-release nitrogen fertilizer, nitrification inhibitor and urease inhibitor, and optimal nitrogen fertilizer rate based on soil nitrogen tests), large farm sizes, flue gas denitration and healthy diet habits are effective strategies to cope with the continued growth of N 2 O emissions. The results of these quantitative scenario simulations are critical for the formulation and implementation of corresponding policy measures. • Temporal and spatial variations in N 2 O emissions were quantified. • The total N 2 O emissions in China increased by 140% from 1978 to 2015. • The N 2 O emissions in China contribute 9–20% of the CO 2 -equivalent GHG emissions. • A quantitative N 2 O mitigation potential is proposed. • Knowledge-based N management is an effective scenario for mitigating N 2 O emissions. [ABSTRACT FROM AUTHOR]

Remanufacturing and direct reuse are considered important measures for promoting the circular economy and improving resource efficiency. Automotive production is a typical resource- and energy-intensive industrial sector, and is a prime market for remanufacturing and direct reuse. Assessing the effect of remanufacturing and direct reuse on the automotive production industry from the perspective of resource efficiency will provide an important reference for improving understandings of remanufacturing and guiding relevant policies in a broader context. A literature review reveals few studies focusing on the resource efficiency of remanufacturing and direct reuse, and the relative lack of a generally accepted indicator to assess the resource efficiency of industrial processes. This paper promotes a new indicator, resource productivity of industrial process , and constructs a material flow model to calculate the resource productivity of China’s automotive industry. Results suggest that the indicator and its analytical model are effective tools to assess resource efficiency. Results also suggest that compared to a case where remanufacturing and direct reuse are not employed, adding these processes in China’s automotive supply chain would increase resource productivity of industrial process by 7.1% in a high efficiency scenario. Based on these findings, policy recommendations for applying the indicator at industry level and encouraging remanufacturing and direct reuse are provided. [ABSTRACT FROM AUTHOR]

The expansion of motor vehicle fleet in China during the past decade has produced a cascade of challenges, including dealing with end-of-life passenger cars. To date, these cars have not been effectively collected or recycled. Policies must be deliberately devised and reformed to facilitate state-of-the-art vehicle recycling and minimize waste arising from end-of-life cars. In this study, dynamic modeling and cost-benefit analysis have been employed to investigate how polices, including government subsidies, a value added tax and a deposit-refund system, may affect recycling of end-of-life passenger cars. The results indicate that a combination of deposits and subsidies will surpass all of the other independent policies in terms of the recycling rate. This combination is expected to lead to a recycling rate of 80% of end-of-life passenger cars by 2050. However, the government will have to pay an annual 62 billion Chinese Yuan in the middle of the century for old-for-new replacement subsidies, posing a heavy burden on public finance. Comparatively, the deposit-only scenario will cost the government 4.7 billion Chinese Yuan and elevate the recycling rate to 46% in 2050. These policies may help curb the black market and promote the legitimate business of dismantling and recycling in the long run. Moreover, the prospect of vehicle remanufacturing will play another key role in diminishing the black market. The results in China are compared with policies and practices in Europe, Japan and South Korea to help decision-makers develop the most appropriate strategies for end-of-life vehicle management. [ABSTRACT FROM AUTHOR]