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The battery electric vehicle (BEV) industry, commanding over half of the global market share in China, has garnered significant attention in response to escalating concerns about climate change. NCM (LiNi x Co y Mn z O 2) batteries, prized for their high energy density, are pivotal in this industry. However, their production relies on critical metals, posing environmental challenges. Recycling processes aim to address this issue by recovering critical metals from end-of-life batteries. The industry is updating from NCM 111 to NCM 811 batteries to enhance energy density and reduce costs, but the key factors influencing the material flows and environmental impacts remain uncertain. This paper aims to identify the key factors contributing to the potential differences in material flows and environmental impacts introduced by the NCM battery upgrading in China. Following the new energy vehicle sales projections in China until 2035, a dynamic material flow analysis was employed to calculate material demands, recovered amounts, and substitution rates for various upgrading scenarios. The study reveals that the majority of retired batteries until 2035 were sold between 2022 and 2029. Material substitution rates prove to be more sensitive to the upgrading scenario than the lifetime and growth rate of BEVs. Faster NCM 811 penetration results in over 2.5 times more saved cobalt demand compared to additional nickel demand. A life cycle assessment of NCM batteries reveals a 39% lower global warming impact for NCM 811 compared to NCM 111, highlighting environmental benefits from increased energy density and reduced cobalt consumption. The energy density improvement contributed 85%, while the alteration in material composition contributed 15% to the global warming reduction in NCM 811. Recycling emerges as a crucial strategy in mitigating environmental impacts across all categories, particularly addressing eutrophication, previously deemed challenging due to the difficulty in recovering Li 2 CO 3. [ABSTRACT FROM AUTHOR]

The increasing contribution of refrigeration systems to global warming has led to widespread demand for low global warming potential (GWP) refrigerants as alternatives. This paper proposed a comprehensive environmental assessment method for evaluating the carbon footprint of units charged with low-GWP refrigeration. Experimental and numerical studies were used to investigate the carbon footprint impact of using alternative refrigerants at different ambient temperatures in China. Initially, the model was validated through experimental case studies on the use stage of cold storage units. Subsequently, a comparison was made between the cooling capacity (CC) and energy efficiency ratio (EER) of cold storage units charged with different refrigerants. Additionally, the impact of alternative refrigerants in the use stage was analyzed by numerical calculations, and the adaptability of the cold storage unit to the ambient temperature and the national energy structure was also studied. The results indicate that among the four stages of the cold storage unit, the use stage is the hotspot of carbon footprint due to the large amount of energy consumption and the existence of refrigerant leakage and other behaviors. Utilizing low-GWP alternative refrigerants could significantly reduce the carbon footprint of the cold storage units' use stage by 10.56%–16.39%, thereby lowering the whole stage carbon footprint. Furthermore, the ambient temperature and national energy structure could also effectively reduce the carbon footprint of cold storage units' whole stage by 1%–27.17%. Furthermore, after adopting low GWP refrigerants, the life-cycle cost (LCC) of the units have also decreased by 6.1%–12%. Taking into account both environmental impact and economic considerations, it is recommended to directly replace R404A with R448A in the units in regions where the average ambient temperature is above 15 °C. • A carbon footprint evaluation model for the units was established. • Influencing factors of carbon footprint are studied numerically and experimentally. • By GHG assessments, the optimal refrigerant and external conditions were determined. • Alternative refrigerants reduce carbon emissions for cold storage units by 8.8%–24.92%. [ABSTRACT FROM AUTHOR]

The surge in energy consumption and CO 2 (carbon dioxide) emissions is exacerbating global warming. The Chinese government has promised to reduce CO 2 emission by 60%–65% per unit of GDP over the 2005 level by around 2030. Analyzing the factors influencing CO 2 emissions is one of the key aspects involved in effectively reducing greenhouse gas emissions. In this paper, we add climatic factors based on socio-economic factors, and adopt the extended STIRPAT model to investigate the mechanism driving emissions by the co-action of natural and socio-economic factors. The results show that the 1995–2014 emissions in China's Zhejiang province had an upward trend with growth rates varying between intermediate periods. The order of the factors' elasticity coefficients is urbanization rate (0.181) > GDP per capita (0.180) > population (0.177) > energy intensity (0.170) > trade openness (0.170) > cooling degree days (0.127) > mean temperature anomaly (0.116). Economic development and urbanization were the main factors promoting CO 2 emissions in 1996–1999, while economic development and foreign trade were the main factors in 2000–2014. Policy makers should pay more attention to keeping a healthy pace of economic development, introducing more low energy consumption and low pollution enterprises and encouraging technological innovation. Improving the quality of urbanization, guiding a sustainable lifestyle, adjusting the structure of foreign trade and curbing energy intensity are also expected to reduce emissions. [ABSTRACT FROM AUTHOR]

Recently, comprehensive attention has been attracted to global warming. Meanwhile, China is a country with huge energy consumption and greenhouse gas emission. Therefore, it is urgent for China to reduce the air pollutants embodied in each unit of a good for a less greenhouse gas earth. In this paper, air pollutants embodied in goods consumption as well as import-export trade in China was accounted in 1995–2009. Besides, we checked the structural decomposition analysis of emissions' variation. The results showed: (1) in 1995–2009, air pollutants embodied in goods for consumption and import-export trade in China displayed a rising trend. Emission of carbon dioxide was the largest and methane, carbon monoxide, sulphur oxides, non-methane volatile organic compounds, nitrogen oxides, ammonia, nitrous oxide were in proper sequence based at the average level. (2) Air pollutants embodied in goods exported were larger than those in imported and difference among nations existed. (3) The percentages of carbon dioxide, methane, nitrogen oxides, sulphur oxides, carbon monoxide, non-methane volatile organic compounds embodied in Construction were larger than in other departments on the consumption side, while percentages of carbon dioxide, nitrogen oxides, sulphur oxides, carbon monoxide, non-methane volatile organic compounds embodied in Electrical and Optical Equipment was bigger on the trade side. (4) Emission reduction techniques reduced air pollutants embodied in goods consumption and import and export trade in China. Consequently, China ought to pay attention to emission reduction of carbon dioxide and raise awareness of air pollutants controlling, especially in Construction, Electrical and Optical Equipment and other departments. More importantly, China ought to strengthen cooperation with other nations in emission reduction and developing technologies so as to cut down air pollutants, not only for China but also for the earth. [ABSTRACT FROM AUTHOR]

To mitigate global warming, CO 2 emission reduction has become an urgent issue in the energy sector. In China, coal-to-gas, carbon capture and renewable energy utilization are important measures available among various low-carbon plans. However, inadequate gas supply, unclear utilization methods of captured CO 2 , and curtailment of excessive wind and solar power have hampered the effective implementation of the above measures. To solve this issue, this paper presents a coupling model considering power to gas (P2G) technology and carbon capture power plants (CCPP), and extends it into an integrated energy system (IES) including electricity, thermal and gas, then proposes an economic and environment-friendly scheduling model at a high wind power penetration level. Through the coupling of CCPP and P2G in IES, most of CO 2 emitted by the system can be captured and sent to the P2G facility to produce synthesized gas, which provides a new idea of utilizing CO 2 rather than storage. The synthetic gas can be provided to the system to reduce the external gas dependency. In addition, the simulation results also show that the ability of the system to absorb renewable energy is significantly enhanced with the presence of CCPP and P2G. [ABSTRACT FROM AUTHOR]