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SCR denitrification technology and its application in our country
This paper describes selective catalytic reduction (SCR) for NOx control that removes NOx from flue gas and has been used by developed countries in the world.Its principle,craft process and applications are also introduced.And the discussion about taking the technology into practice in our native coal-fired power plants has been made.
Research progress on recycling technology of waste lithium iron phosphate battery
CAO Chali;ZENG Fanle;YANG Hao;WANG Xueying;LIU Zhaomeng;GAO Xuanwen;[Objective] The recycling technology of waste lithium iron phosphate batteries not only extracts valuable metals and reduces resource waste but also alleviates dependence on imported lithium resources, promoting industrial transformation and technological advancement. However, in the face of the explosive growth of waste lithium electronic batteries, how to recycle waste lithium iron phosphate batteries more efficiently has become a crucial issue,necessitating more in-depth research on recycling mechanisms and technologies. [Methods] In this paper, the latest research progress in the recycling of cathode materials for waste lithium iron phosphate batteries is systematically reviewed and summarized. The principle, advantages and disadvantages and application prospects of pretreatment technology(discharge, crushing and separation) and valuable metal recovery technology(pyrometallurgy, wet process,electrochemistry and mechanochemistry) of waste lithium iron phosphate batteries are analyzed. The solid phase and liquid phase process characteristics of in-situ regeneration of lithium iron phosphate cathode materials are analyzed, and the problems and challenges of the process are discussed. [Results] Existing research shows that for the recycling technology of waste lithium iron phosphate batteries, various methods have their own advantages and disadvantages. In the recycling process, pyrometallurgy is simple to operate but has high energy consumption; hydrometallurgy has high recovery efficiency but consumes a lot of reagents; electrochemical methods are environmentally friendly and efficient but have high equipment costs; mechanochemical methods are relatively simple to operate but require high equipment performance. In addition, in-situ regeneration technology can directly restore the electrochemical performance of waste battery materials, but there are still certain challenges in cost control and process efficiency. The combination of different pretreatment technologies and recovery processes further increases costs, efficiency, and technical complexity.[Conclusion] Therefore, to achieve efficient, low-cost, and environmentally friendly recycling of waste lithium iron phosphate batteries, it is necessary to optimize existing processes or develop new green, low-cost processes to improve the recovery rate of valuable metals and the performance of regenerated materials. Additionally, promoting the scaling and industrial application of recycling technologies, as well as formulating and improving relevant policies and regulations, are also urgent issues to be addressed. This paper summarizes the latest progress in recycling technology,providing a reference for the sustainable development of the battery industry.
Progress in new energy storage based on compressed carbon dioxide
ZHAI Xuan;WANG Song;FAN Xiaoping;ZHOU Jia;QIN Xiaowen;YAN Xuewen;LIU Junwei;ZHANG Yilun;LIU Zhan;DEC Dongfang Turbine Co., Ltd.;College of Electromechanical Engineering, Qingdao University of Science and Technology;Accelerating the deployment of renewable energy and building a new type of power system are important measures to address energy and environmental issues. Energy storage technology is an important equipment foundation of the novel power system. It can not only realize the transfer of energy over time and smooth the power output of renewable energy, but also balance the energy management at the supply side and the user side. First, the technical principles and application status of compressed carbon dioxide energy storage is summarized in this study.Subsequently, the storage configuration of the system is divided into seven categories based on the storage state of carbon dioxide. The performance characteristics and research progress of different storage configuration systems are summarized. Finally, the development direction of the compressed carbon dioxide energy storage system is predicted.(1) Compressed carbon dioxide energy storage is a new type of physical energy storage technology. Compared with compressed air energy storage, it has the advantages of large energy density and compact system, and has been widely concerned by scholars in recent years. Carbon dioxide has a critical point of 7.38 MPa/31.3 ℃ and is more easily liquefied than air. In addition, carbon dioxide has the characteristics of low viscosity and high density, so compressed carbon dioxide energy storage systems are more compact compared to compressed air energy storage systems at the same power level. At present, carbon dioxide energy storage verification projects have been completed and put into operation both domestically and internationally.(2) According to the different carbon dioxide states in the low/high pressure storage device, the storage scheme of compressed carbon dioxide energy storage technology can be divided into seven types: gas-supercritical carbon dioxide storage, gas-liquid carbon dioxide storage, supercritical-supercritical carbon dioxide storage, liquid-supercritical carbon dioxide storage, liquid-liquid carbon dioxide storage, adsorption-liquid carbon dioxide storage and adsorption-supercritical carbon dioxide storage.(3) In the future technology development of compressed carbon dioxide energy storage, mainly focus on gas-liquid carbon dioxide storage compressed carbon dioxide energy storage technology and liquid-liquid carbon dioxide energy storage technology. Fully utilize the advantages of high cycle efficiency, simple system structure of compressed carbon dioxide energy storage technology with gas-liquid carbon dioxide storage and high energy density of compressed carbon dioxide energy storage technology with liquid-liquid carbon dioxide storage.(4) In terms of the diversified development of compressed carbon dioxide energy storage technology, the first is to implement the "renewable energy + compressed carbon dioxide energy storage" model to achieve sustainable and stable power supply of renewable energy, assist the operation of the grid,and reduce the phenomenon of abandoned light and power. The second is to conduct in-depth research on integrated systems based on compressed carbon dioxide energy storage technology, improving system performance and energy utilization rate by coupling ejector refrigeration cycles, organic Rankine cycles, etc., which can achieve carbon dioxide condensation and waste heat reuse. At present, only a few compressed carbon dioxide energy storage verification projects have been completed, and the development of carbon dioxide energy storage technology should be accelerated at home and abroad to realize the promotion of compressed carbon dioxide energy storage technology from theory to practice, from concept research and development to project demonstration and ultimately achieving widespread application of compressed carbon dioxide energy storage technology.
Numerical simulation of different guide plates in selective catalytic reduction denitrification reactor of 600MW power plant
The research was based on guide plates in selective catalytic reduction denitrification reactor of 600 MW power plant.Three different shapes of guide plates were simulated by using Fluent.The appropriate shapes of guide plates and reasonable flow in SCR reactor were obtained.The flow straightener was added in SCR reactor in order to improve the flow.
Processes and prospects of air pollutant control in coal-fired power plants in China
ZHU Fahua;XU Jingxin;WANG Sheng;ZHANG Qian;XU Yueyang;LI Xiaolong;The transformation of ultra-low emissions in Chinese coal-fired power plants has been widely completed,leading to a significant improvement in environmental air quality.In order to determine whether further need to tighten the pollutant emission standards and continue to develop new flue gas control technologies for coal-fired power plants,this study presented an outlook on emission standards and flue gas control technologies.This outlook is based on a systematic systematic review of the development history of Chinese coal-fired power plants and the history of atmospheric pollutant control,considering the fact of still high proportion of the atmospheric pollutant emissions in the thermal power industry and urgent need for continuous improvement of air quality.(1) The Chinese power industry has undergone four distinct phases since its inception in 1882:a tentative start,challenging entrepreneurship,vigorous growth,and remarkable achievements.In comparison to the early days of China,national installed capacity and electricity generation have increased by 1383 and 1950 times,respectively.Since 2013,China has consistently ranked first in the world in terms of installed capacity and electricity generation,surpassing the combined total of the G7 countries in 2022.Over the past century,coal-fired power generation,characterized primarily by coal-based facilities,has dominated China's installed capacity and electricity generation.Individual plant capacities have gradually increased,with the construction of the world's largest single-unit,lowest coal consumption coal-fired power generation unit with a capacity of 1.35 million kW completed in 2021.While the installed capacity of thermal power generation continues to grow,its proportion has declined from83.3%in 2006 to 53.0%in 2022.(2) Prior to 1991,Chinese coal-fired power plants had no emission concentration standards for dust,sulfur dioxide (SO2),or nitrogen oxides (NOx).Over the past three decades,emission standards for atmospheric pollutants in coal-fired power plants have undergone three revisions,transitioning from the world's most lenient limits to the strictest limits,driving the achievement of ultra-low emissions in Chinese coal-fired power plants.Simultaneously,significant advancements have been made in the technologies for controlling dust,SO2,and NO_xemissions,setting global benchmarks.In 2007,China began implementing desulfurization electricity pricing policies,followed by denitrification electricity pricing policies in 2011,the addition of dust removal electricity pricing in 2014,and the introduction of ultra-low emission electricity pricing policies in 2016.These policies have played a crucial role in ensuring the efficient operation of flue gas control facilities.Under the guidance of China's environmental protection authorities,a comprehensive technical standard system for flue gas control has been gradually established,covering the entire process from emission standards to technical guidelines,engineering specifications,acceptance testing,and operational management.In comparison to the peak emissions of dust and SO_2in the thermal power industry in 2006,emissions in 2022 decreased by 97.3%and 96.4%,respectively.Furthermore,compared to the peak NO_xemissions in the thermal power industry in 2011,NO_xemissions in 2022 decreased by 93.1%.(3) China's annual average concentration of PM2.5in environmental air quality standards is seven times higher than the World Health Organization's guideline values and 2.3times higher than the value of U.S.1997 standard.The actual level of PM2.5in China's environmental air is more than four times that of the U.S.and more than three times that of countries like Russia and Brazil.To align with the goals of creating a"Beautiful China"and a"Healthy China,"China's annual average PM2.5concentration in environmental air quality standards needs to decrease by at least 50%.In 2020,emissions of SO_2and NO_xfrom the thermal power industry accounted for 30.8%and 20.9%of the total emissions from industrial sources,respectively.Drawing on the experiences of developed countries in improving air quality and considering the continuous growth in China's coal consumption,it is imperative for the thermal power industry to reduce its atmospheric pollutant emissions by at least 70%or more.Achieving this requires breakthroughs in integrated dust,sulfur,and nitrogen control technologies,as well as costeffective,energy-efficient retrofit technologies,to enable coal-fired power plants to achieve ultra-clean emissions.
Study on countermeasures and defense of electromagnetic pollution
Electromagnetic pollution has become the chief physical pollution. Classification, spread and key point factors of electromagnetic pollution and resource of electromagnetic radiation are reviewed. Harm, effect and interfence of electronic equipment radiation on electronic equipment are pointed out. Finally, some defensive measures and suggestions are presented.
Technical and economic analysis and outlook of hydrogen energy industry
WANG Fei;YU Mengyi;CHEN Liangyong;Productivity Center Of Jiangsu Province;Under carbon peaking and carbon neutrality goals, hydrogen energy assists the power production system,it's great significance for carbon peak and carbon neutralization. This paper introduces the development status, significance and application prospect of the hydrogen energy industry; summarizes the current economic and technological development of hydrogen industry in hydrogen production, storage and transportation, and hydrogen energy application,and focuses on the analysis of the technical and economic problems in the storage and transportation process of the hydrogen industry chain, and compares the levelized cost of the different ways of storage and transportation, including the gas-hydrogen long-tube trailer, tanker transportation, pipeline transportation, and marine transportation, and the results of this analysis show that the gas-hydrogen transportation by pipeline has the lowest storage and transportation cost, and is suitable for long-distance, large-scale and large-scale transportation. The analysis results show that pipeline hydrogen transportation has the lowest storage and transportation costs and is suitable for long-distance, large-scale and stable hydrogen demand scenarios; small-scale liquid hydrogen has the highest storage and transportation costs and is mainly used in aerospace and less for civilian use; high-pressure cylinder hydrogen storage and high-pressure gas-hydrogen long-tube trailer technology is mature and is the mainstream storage and transportation mode at home and abroad, which is not suitable for large-scale and long-distance transportation. Hydrogen industry still has various challenges such as high cost, safety risk and conversion efficiency in hydrogen production, storage and transportation,and hydrogen application. The future development of hydrogen energy needs to be improved in terms of no breakthroughs in key technologies, reduction of operating costs, development of related technical standards, and government subsidies. It is of great significance to predict the cost of hydrogen production, storage, transmission,distribution and application in the era of large-scale hydrogen energy, and the trend of marketization.
Ways to reduce the emission of CO_2
Under the stress of Kyoto Protocol, the emission of CO2 must be controlled in near future in China. According to the actual condition of energy consumption in China, the roles of CCT, IGCC, renewable energy development and forest coverage upgrading in the reduction of CO2 are discussed. It indicates that CDM items cooperated with developed countries are the main countermeasure to solve the problems of laggard technology and capital deficiency.
Research progress on dry desulfurization in coal-fired power plant
CHEN Kuaixu;BIE Xuan;LIU Yuanyuan;SO2 is one of the main pollution sources of air pollution in China. The most mature desulfurization method is removed by wet limestone gypsum,which has the high SO2 removal efficiency. Howeve,it also brought a lot of drawbacks at the same time,such as desulfurization wastewater treatment,high humidity flue gas discharge and so on. The new pollution came up with the SO2 removal. The basic method to solve this problem is to change the desulfurization technology. Due to its avoidance of corrosion and avoid the water participation,dry FGD process has attracted people's attention. It introduces several typical desulfurization methods to provide reference.