Contributions of cleaner production and end-of-pipe treatment to NOx emissions and intensity reductions in China, 1997-2018

Sustainable solid waste management system using technology-enabled end-of-pipe strategies

Ever Increasing accumulation of solid waste, attributed to population growth and rapid urbanization, is a serious issue for all nations. This creates hindrance in implementing sustainable solid waste management systems (SWMS), which contribute to socio-economic-environmental-operational (SEEO) benefits for the nations and their citizens. Limited understanding of various solid waste management (SWM) practices, their operational sequence, and other system constraints pose numerous challenges for the concerned authorities and policymakers. This paper provides a framework depicting three broad categories of strategies for managing solid waste: preventive, end-of-pipe (EOP), and environmental restoration. Among these, the research emphasizes on EOP strategies, being suitable alternative as per current requirements, to deal with massive amounts of generated waste. It further adopts Grey-DEMATEL approach to models the causal relationship among EOP strategies to identify the most influential strategy, which influences other ones. The model suggests waste segregation to be the major enabler for other EOP strategies, as it has maximum overall significance value (R + C) between 1.18 and 1.41 and it is the only one with positive value in "net-effect" computation (R-C), compared to other strategies with negative (R-C) values. This would enable concerned authorities to understand and follow the sequence of actions. Finally, a comprehensive framework is proposed for effective, efficient, and sustainable methods of handling different types of solid waste using technology-enabled EOP strategies. A case study is performed to demonstrate the significance of waste segregation towards SEEO benefits. It indicates that technology-based solutions at decentralized depots and establishment of biogas plant in the vicinity of garbage collection point leads to reduction in transportation cost and energy saving in efficient manner. The ground level implementation of our research in an Indian city resulted in the reduction of daily vehicle requirement from 25 to 20 vehicles, leading to approx. 25% savings in overall transportation costs thereby cutting exchequer's bill by up to $ 2820/month. It also reveals that mechanized and decentralized solutions were not effective for inert waste, its disposal to landfill was more suited alternative.

Mapping the heterogeneity of global methane footprint in China at the subnational level

Achieving the ambitious Global Methane Pledge announced in the Glasgow Climate Pact requires collaborative efforts from both the signatory countries and China which serves as the world's largest emitter. Considering the heterogeneity of economic structures within China and the relocation of emissions between regions via the global economic network, it is vital to investigate how China's methane emissions at the subnational level are linked to global final consumption. In this paper, we mapped global methane footprint in China from 2007 to2015 at the subnational level, by nesting China's interprovincial input-output tables into global multiregional input-output accounts and upscaling grid-level methane emission data of the Edgar database to the provincial level. Our results suggested that global methane footprint in China shifted westward, and the United States, European Union, Japan, and Hong Kong were the main drivers of China's local methane emissions. By illustrating the international and interprovincial trade flows of methane emissions, this study demonstrated that southeast coastal provinces were the hotspots for global methane footprint while middle inland provinces were the emission hotspots for China's domestic demands. We also showed how China's methane emissions were distributed through the nested global economic network to different economic agents. Moreover, emission trends of key exporting sectors for China's eight economic zones were detailed discussed. The outcome of this study may be fully supportive for identifying the heterogeneous effects of global methane footprint in China and implicative for interprovincial and international collaborations towards methane emission mitigation.

Common Driving Forces of Provincial-Level Greenhouse Gas and Air Pollutant Emissions in China

By developing a filtering framework and a sector-level multi-regional input-output structural decomposition model, this study identifies key common emission sources, motivation sources, and inter-provincial emission flows of both GHGs and air pollutants and reveals the key driving forces of changes in different emissions from 2012 to 2017. Results show that key common emission sources are electricity sector, non-metallic mineral products, and smelting and processing of metals in Shandong and Hebei. However, key common motivation sources are the construction sectors in Guangdong, Henan, Jiangsu, Zhejiang, and Shandong. The key inflow regions include Guangdong and Zhejiang and key outflow regions include Jiangsu and Hebei. The emission reductions are attributed to the emission intensity effect of the construction sector; contrastingly, the emission increase is from the investment scale of the construction sector. Here, Jiangsu could be a key target for future emission reduction because of its high absolute emissions and low past reduction. The scale of investment in construction might be a significant factor in reducing emissions in Shandong and Guangdong. Henan and Zhejiang could concentrate on sound new building planning and resource recycling.

Driving factors of NOX emission reduction in China's power industry: based on LMDI decomposition model

Under the policy background of "joint prevention and control" of global greenhouse gas emission reduction and regional air pollutants, the power industry, as an important target industry of energy conservation and emission reduction policies, has become an effective choice to release dual pressures. In this paper, the "bottom-up" emission factor method was used to measure the emission of CO₂ and NO_X from 2011 to 2019. Then, the contributions of six factors to NO_X emission reduction in China's power industry were identified using the Kaya identity and logarithmic mean divisia index (LMDI) decomposition methods. The research results show that (1) there is a significant synergistic emission reduction effect between CO₂ emission reduction and NO_X emission reduction; (2) the factor that inhibits the growth of NO_X emissions reduction in the power industry is economic development factor; and (3) the main factors that promote the reduction of NO_X emission from the power industry are synergy effect, energy intensity, power generation intensity, and power production structure factors. Several suggestions are proposed, which are the power industry should adjust its structure, improve energy intensity, focus on applying low-nitrogen combustion technology, and improve the air pollutant emission information disclosure system to reduce NO_X emissions.