• Energy Research

Abstract As an energy storage device, battery has been rapid developed in recent years with the typical environmental problems such as consumption of resources and heavy metal pollution. Therefore, it is urgent to conduct a comprehensive analysis and in-depth interpretation of the environmental impact of the battery industry to reduce environmental pollution. Life cycle assessment is applied to analyze and compare the environmental impact of lead acid battery (LAB), lithium manganese battery (LMB) and lithium iron phosphate battery (LIPB) within the system boundary of “cradle-to-gate”. The key processes and the key substances of environmental impact are identified by the traceability. The results showed that the overall impact of LIPB production on environment is the smallest. The key substances that cause the environmental impact of LAB production process are refined lead and tin. Lithium manganate and aluminum shell are the key substances that cause the environmental impact of lithium manganese oxide production process. The key substances that cause the environmental impact of lithium iron phosphate production process are lithium iron phosphate and aluminum shell. According to the position of each key substance in the process, the Reduce-Reuse-Recycle principle of circular economy theory is adopted to suggest the corresponding optimization. This research can provide useful reference for government decision-making and the sustainable development of battery industry.

Micro-energy networks have been widely used in power distribution systems. Previous studies have not addressed how to avoid these networks being dependent on the grid, due to the instability of distributed energy sources, or the lack of specific quantification of environmental and economic benefits. To understand the overall potential of the micro-energy network system for reducing environmental impacts, a life cycle assessment was conducted for the industrial park in Jinan. The analysis used a “cradle to gate” system boundary and a 1-year operation of the micro-energy network as the functional unit. The HOMER software was applied to build the research object’s micro-energy network model and to carry out load analysis. The environmental impact and financial costs of the micro-energy network system have been estimated for different combinations of gas turbine units and water chilling units. The results show that all optimized scenarios could achieve an environmental impact reduction of more than 50% when compared to the initial scenario, regardless of the benefits of exporting surplus electricity. A reduction in environmental impacts as high as 71% could be achieved in optimized scenarios, although total costs would be 13% higher. The categories of freshwater ecotoxicity, marine ecotoxicity, human carcinogenic toxicity, and human noncarcinogenic toxicity were determined as the key impact categories. The impact of different electricity generation and the environmental benefits of exporting electricity are discussed. We concluded that micro-energy networks integrating natural gas and renewable energy technologies could bring about significant environmental benefits.

Abstract Increasingly stringent pollutant emission standards pose a new challenge to the control of air pollutants in China's iron and steel industry (ISI). This study quantified and compared the environmental and economic effects of three typical sintering flue gas ultra-low emission treatment technologies in China's ISI, namely, semi-dry flue gas desulfurization + semi-dry flue gas denitration with O3 + bag filter (SSOB), wet flue gas desulfurization + wet electrostatic precipitator + selective catalytic reduction denitration (WWS), and semi-dry flue gas desulfurization + bag filter + selective catalytic reduction denitration (SBS) by conducting a life cycle assessment coupled with life cycle costing method. Using 1 ton of sinter as the functional unit and “cradle to gate” as the system boundary, the environmental impact of the three treatment technologies is 0.1822, 0.1298, and 0.117, respectively and the total economic cost is 11.622, 10.353, and 10.435 RMB, respectively. The ozone oxidation, semi-dry flue gas desulfurization (FGD), and semi-dry flue gas denitration processes are the key processes of SSOB with electricity, liquid oxygen, and sodium sulfite as key substances. Wet flue gas desulfurization process and selective catalytic reduction (SCR) denitration process are the key processes in WWS while electricity is the key substance. Semi-dry FGD and SCR denitration are the key processes in SBS, with electricity and lime as the key substances. SBS has optimal environmental performance, while WWS has lowest economic costs. Optimization suggestions for each technology are presented based on the influence degree of key processes. The research findings will be valuable for the selection and optimization of ultra-low emission technologies of ISI.

China's economy has risen to the second place since 2010, accompanied by the largest energy consumption in the world. As one of the major air pollutants from the fossil fuel, excessive SO2 emissions have severe negative impacts on eco-environments. In order to achieve the balance between economic growth and environmental protection, many efforts have been made on the reduction of SO2. The route map for the reduction of SO2 in China includes policy setting, economic and energy structure adjustment, and the construction of desulphurization facilities. These initiatives and efforts together had resulted in the significant reduction of SO2 emissions along with fast economic development. This study provides a useful reference for other developing countries in coping SO2 control. The findings also provide implications for reducing the other two air pollutants with binding control targets in the Twelfth Five-Year Plan period in China, i.e. NOx and CO2.

Abstract Straw pulp in China, which is the world's largest producer of this material, suffers from water and energy shortages during its entire life cycle. However, limited systematic studies have focused on these issues, and decision makers need be provided with improvement methods for the environmental performance. Thus, an impact-oriented energy and carbon coupled water footprint analysis was conducted in this study based on ISO standards. Results showed that the impact of energy consumption and carbon emissions exceeded that of water footprint. Carcinogens, non-carcinogens, and freshwater ecotoxicity also played effective roles in improving the environmental performance. Optimizing key indirect processes, including chemicals production, steam preparation, electricity generation, wood pulping, and fertilizer recovery, dominated the reduction in environmental burdens. Direct freshwater consumption and wastewater disposal played additional effective roles in controlling water footprint. The water network was thus optimized by a water pinch analysis to decrease the freshwater consumption and pollutant emissions by maximum values of 91.5% and 99.7% after optimization, respectively. Meanwhile, carbon dioxide, methane, chromium, arsenic, mercury, titanium, copper, strontium, total nitrogen, total phosphorus, BOD5, and COD were the main pollutants. Overall, the environmental impact can be further reduced by diminishing coal power ratio in national energy structure, adopting recovered steam, and considering multistage regeneration water network to cope with different water use demands.

The Yellow River is an important ecological shelter zone and economic belt in China. However, rapid urbanization and industrialization has produced a fragile ecological environment conditions and unbalanced economic development in the Yellow River Basin (YRB). Ecological protection and high-quality development of the YRB has been China's national strategy since 2019. As the only coastal province with the largest economy and population in the YRB, the sustainable development of Shandong Province is of great importance in the region. This study evaluated the dynamic trend of sustainability levels of the nine cities in Shandong Province in the YRB through emergy analysis. Emergy-based indicators were established and analyzed from 2010 to 2019, taking account of the ecological service emergy (ESE) needed to dilute pollutants and emergy equivalent loss (EEL) on ecosystem quality and human health damage. Results showed that emergy sustainable indicators (ESI) in Tai'an, Heze, Dezhou, and Liaocheng ranged from 1 to 10, which had the potential for sustainable development. The ESI value of Jinan, Jining, Zibo, Dongying, and Binzhou was less than 1, which indicated that these cities were under great ecological pressure. The value of emergy indicators for sustainable development (EISD) of the nine cities all declined from 2010 to 2016, but remained stable from 2017 to 2019. Based on findings from the emergy analysis regarding policy implications and local conditions, the study concludes by providing proposals to improve regional sustainability.

System fluctuations of eco-industrial symbiosis network (EISN) organization due to disturbance are very similar to the controller adjustment in the automatic control theory. Thus, a methodology is proposed in this study to assess the vulnerability of EISN based on the automatic control theory. The results show that the regulator plays a key role to enhance the resilience of the network system to vulnerability. Therefore, it is imperative to strengthen the real-time regulation and control of EISN so that the system stability is improved. In order to further explore the impact of various regulations on the system vulnerability, the influence of system stability is simulated by means of proportional, differential, and integral control. A case study with Guigang eco-industrial park (EIP) was undertaken to test this model. The results showed that when the system was disturbed at different positions, the key nodes which had great influence on system vulnerability could be selected according to the magnitude of simulation curve. By changing the ratio coefficient of proportional, differential, and integral units to adjust the ecological chain network, the system's resilience to vulnerability can be enhanced. Firstly, if basic conditions of EISN organization remain unchanged, the integral control of the policy support and infrastructure sharing should be strengthened. Secondly, the differential regulation should be improved continuously for the technological innovation capability of key node enterprises. Finally, the key chain filling projects should be introduced for proportional control so that the chain network design can be optimized from the source.