Problems of Hazardous Waste Storage Facilities in Coal-fired Power Plants and Countermeasures

The hazardous waste produced by coal-fired power plants are large in quantity and variety. It is important for ecological environment protection to properly store hazardous waste in coal-fired power plants. The environmental management of hazardous waste in coal-fired power plants started late, and there are many problems in the construction and management of their storage facilities. In this paper, taking eight typical coal-fired power plants as examples, the present problems of hazardous waste storage facilities in coal-fired power plants are analyzed, and corresponding countermeasures are put forward to solve the main common problems.

Quantifying social costs of coal-fired power plant generation

Coal has been dominating the electricity supply in Indonesia,especially in long-term power generation from fossil energy.This dominance is due to lower production costs in coal-fired power plant generation.However,this low price is only based on monetary costs and ignores the social costs.Therefore,this study aims to quantify the social costs of coal-fired generation.Using QUERI-AirPacts modeling,the present study quantifies the social costs resulting from the Tenayan Raya coal-fired generation in Riau,Indonesia.It includes the levelized cost of electricity and health costs into the generation costs.After that,this study calculates the net present value,internal rate return,and project payback period.The study found that as much as$50.22/MWh was the levelized cost of electricity.While$15.978/MWh or$0.015978/kWh was the social cost that was not included in the generating cost.At the electricity production level of 1,380,171.69 MWh per year,there is an expected extra cost of$22,052,383.30 uncounted when externalities are included.For instance,the net present value(NPV)is lower and even negative when external costs are included(-$24,062,274.19)compared to$176,108,091.52 when externalities are not considered.The internal rate of return(IRR)is much higher when the social costs are not considered.The payback period is also shorter when the social costs are excluded than when the externalities are included.This global number indicates that the inclusion of external costs would impact NPV,IRR,and the payback period.This result implies that the government should internalize the external cost to stimulate the electricity producers to conduct cost-benefit analyses.The cost-benefit analysis mechanism would lead the producers to be more efficient.

Influence of flue gas cleaning system on characteristics of PM_(2.5)emission from coal-fired power plants

This study investigated the influence of precipitators and wet flue gas desulfurization equipment on characteristics of PM_(2.5)emission from coal-fired power stations.We measured size distribution and removal efficiencies,including hybrid electrostatic precipitator/bag filters(ESP/BAGs)which have rarely been studied.A bimodal distribution of particle concentrations was observed at the inlet of each precipitator.After the precipitators,particle concentrations were significantly reduced.Although a bimodal distribution was still observed,all peak positions shifted to the smaller end.The removal efficiencies of hybrid ESP/BAGs reached 99%for PM_(2.5),which is considerably higher than those for other types of precipitators.In particular,the influence of hybrid ESP/BAG operating conditions on the performance of dust removal was explored.The efficiency of hybrid ESP/BAGs decreased by 1.9%when the first electrostatic field was shut down.The concentrations and distributions of particulate matter were also measured in three coal-fired power plants before and after desulfurization devices.The results showed diverse removal efficiencies for different desulfurization towers.The reason for the difference requires further research.We estimated the influence of removal technology for particulate matter on total emissions in China.Substituting ESPs with hybrid ESP/BAGs could reduce the total emissions to 104.3 thousand tons,with 47.48 thousand tons of PM_(2.5).

Near-Zero Air Pollutant Emission Technologies and Applications for Clean Coal-Fired Power

Coal is the dominant energy source in China,and coal-fired power accounts for about half of coal consumption.However,air pollutant emissions from coal-fired power plants cause severe ecological and environmental problems.This paper focuses on near-zero emission technologies and applications for clean coal-fired power.The long-term operation states of near-zero emission units were evaluated,and synergistic and special mercury(Hg)control technologies were researched.The results show that the principle technical route of near-zero emission,which was applied to 101 of China’s coal-fired units,has good adaptability to coal properties.The emission concentrations of particulate matter(PM),SO2,and NOx were below the emission limits of gas-fired power plants and the compliance rates of the hourly average emission concentrations reaching near-zero emission in long-term operation exceeded 99%.With the application of near-zero emission technologies,the generating costs increased by about 0.01 CNY∙(kW∙h)-1.However,the total emissions of air pollutants decreased by about 90%,resulting in effective improvement of the ambient air quality.Furthermore,while the Hg emission concentrations of the near-zero emission units ranged from 0.51 to 2.89μg∙m^-3,after the modified fly ash(MFA)special Hg removal system was applied,Hg emission concentration reached as low as 0.29μg∙m^-3.The operating cost of this system was only 10%-15%of the cost of mainstream Hg removal technology using activated carbon injection.Based on experimental studies carried out in a 50000 m^3∙h^-1 coal-fired flue gas pollutant control pilot platform,the interaction relationships of multi-pollutant removal were obtained and solutions were developed for emissions reaching different limits.A combined demonstration application for clean coal-fired power,with the new“1123”eco-friendly emission limits of 1,10,20 mg∙m^-3,and 3μg∙m^-3,respectively,for PM,SO2,NOx,and Hg from near-zero emission coal-fired power were put forward and realized,providing engineering and technical support for the national enhanced pollution emission standards.

Formation and emission characteristics of VOCs from a coal-fired power plant

On-site measurements of volatile organic compounds(VOCs)in different streams of flue gas were carried out on a real coal-fired power plant using sampling bags and SUMMA canisters to collect gas samples,filters to collect particle samples.Gas chromatography-flame ionization detector/mass spectrometry and gas chromatography-mass spectrometry was the offline analysis method.We found that the total mass concentration of the tested 102 VOC species at the outlet of wet flue gas desulfuration device was(13456±47)μg·m^(-3),which contained aliphatic hydrocarbons(57.9%),aromatic hydrocarbons(26.8%),halogen-containing species(14.5%),and a small amount of oxygen-containing and nitrogencontaining species.The most abundant species were 1-hexene,n-hexane and 2-methylpentane.The top ten species in terms of mass fraction(with a total mass fraction of 75.3%)were mainly hydrocarbons with a carbon number of 6 or higher and halogenated hydrocarbons with a lower carbon number.The mass concentration of VOC species in the particle phase was significantly lower than that in the gas phase.The change of VOC mass concentrations along the air pollution control devices indicates that conventional pollutant control equipment had a limited effect on VOC reduction.Ozone formation potential calculations showed that aromatic hydrocarbons contributed the highest ozone formation(46.4%)due to their relatively high mass concentrations and MIR(maximum increment reactivity)values.

Field Studies on the Removal Characteristics of Particulate Matter and SO_(x) in Ultra-Low Emission Coal-Fired Power Plant

In order to reduce the environmental smog caused by coal combustion,air pollution control devices have been widely used in coal-fired power plants,especially of wet flue gas desulfurization(WFGD)and wet electrostatic precipitator(WESP).In this work,particulate matter with aerodynamic diameter less than 10μm(PM_(10))and sulfur oxides(SO_(x))have been studied in a coal-fired power plant.The plant is equipped with selective catalytic reduction,electrostatic precipitator,WFGD,WESP.The results show that the PM_(10)removal efficiencies in WFGD and WESP are 54.34%and 50.39%,respectively,and the overall removal efficiency is 77.35%.WFGD and WESP have effects on the particle size distribution.After WFGD,the peak of particles shifts from 1.62 to 0.95μm,and the mass concentration of fine particles with aerodynamic diameter less than 0.61μm increases.After WESP,the peak of particle size shifts from 0.95 to 1.61μm.The differences are due to the agglomeration and growth of small particles.The SO_(3)mass concentration increases after SCR,but WFGD has a great influence on SO_(x)with the efficiency of 96.56%.WESP can remove SO_(x),but the efficiency is 20.91%.The final emission factors of SO_(2),SO_(3),PM_(1),PM_(2.5)and PM_(10)are 0.1597,0.0450,0.0154,0.0267 and 0.0215(kg·t^(−1)),respectively.Compared with the research results without ultra-low emission retrofit,the emission factors are reduced by 1~2 orders of magnitude,and the emission control level of air pollutants is greatly improved.

Xiangfan Coal-fired Power Plant - a matched large power plant for Three Gorges Project starts to construct

Xiangfan Coal-fired Power Plant, a key energy construction project matched with Three Gorges Project, approved by the State Council. formally started to build in the suburb of Xiangfan City, Hubei Province on November 29, 1996.

Regulations and Practice on Flue Gas Denitrification for Coal-Fired Power Plants in China

In China, according to the relative up-to-date regulations and standards, the maincontrol measure for NOX emission of coal-fired power plants is, in principle, low NOXcombustion. However, in recent years, more and more newlyapproved coal-fired plantswere required to install flue gas denitrification equipment. This article expounds if fluegas denitrification is necessary from several aspects, including constitution of NOX, itsimpact to environment, operation ofdeNOXequipment in USA, as wellas the differencein ambient air quality standard between China and World Health Organization. It setsforth themes in urgent need of study and areas where deNOX equipment is necessaryfor new projects, besides a recommendation that the emission standards for thermalpowerplants should be revised as soon as possible in China.

Progress and prospects of innovative coal-fired power plants within the energy internet

The development of electrical engineering and electronic, communications, smart power grid, and ultra-high voltage transmission technologies have driven the energy system revolution to the next generation: the energy internet. Progressive penetration of intermittent renewable energy sources into the energy system has led to unprecedented challenges to the currently wide use of coal-fired power generation technologies. Here, the applications and prospects of advanced coal-fired power generation technologies are analyzed. These technologies can be summarized into three categories:(1) large-scale and higher parameters coal-fired power generation technologies, including 620/650/700 oC ultra-supercritical thermal power and double reheat ultra-supercritical coal-fired power generation technologies;(2) system innovation and specific, highefficiency thermal cycles, which consist of renewable energy-aided coal-fired power generation technologies, a supercritical CO_2 Brayton cycle for coal-fired power plants, large-scale air-cooling coal-fired power plant technologies, and innovative layouts for waste heat utilization and enhanced energy cascade utilization;(3) coal-fired power generation combined with poly-generation technologies, which are represented by integrated gasification combined cycle(IGCC) and integrated gasification fuel cell(IGFC) technologies. Concerning the existing coal-fired power units, which are responsible for peak shaving, possible strategies for enhancing flexibility and operational stability are discussed. Furthermore, future trends for coal-fired power plants coupled with cyber-physical system(CPS) technologies are introduced. The development of advanced, coal-fired power generation technologies demonstrates the progress of science and is suitable for the sustainable development of human society.

Optimization of an Existing Coal-fired Power Plant with CO²Capture

Nowadays, the worsening environmental issue caused by CO2 emission is greatly aggravated by human activity. Many CO2 reduction technologies are under fast development. Among these, monoethanolamine (MEA) based CO2 capture technology has been paid great attention. However, when connecting the CO2 capture process with a coal-fired power plant, the huge energy and efficiency penalty caused by CO2 capture has become a serious problem for its application. Thus, it is of great significance to reduce the related energy consumption. Based on an existing coal-fired power plant, this paper proposes a new way for the decarburized retrofitting of the coal-fired power plant, which helps to improve the overall efficiency of the power plant with less energy and efficiency penalty. The decarburized retrofitting scheme proposed will provide a new route for the CO2 capture process in China.

Cause Analysis and Countermeasure of Gypsum Rain in Coal-fired Power Plants

Focusing on the phenomenon of gypsum rain while wet desulphurization(WFGD) were adopted in coal fired power plant without GGH, the paper studied and put forward the solutions : (1) desulfurization facilities related equipment modification;(2) optimal operation of existing desulfurization facilities.

Development of Carbon Dioxide Capture Technologies in Coal-Fired Power Plants

With a particular reference to China Huaneng Group's practices in CO_2 capture, this article presents a brief ing on the current development of CO_2 capture technologies in coal-fired power plants both in China and abroad. Sooner or later, the integration of CO_2 capture and storage (CCS) facility with coal-fired power plant will be inevitably put on the agenda of developers.

Re-understanding and Thinking about Environmental Impact of Coal-fired Power Plants under Ultra-low Emission

From the perspective of development background,concepts and related policies of ultra-low emission,according to work practice,some issues and difficulties that need to be paid attention to in the environmental impact assessment of ultra-low-emission thermal power projects were discussed from the aspects of evaluation criteria,evaluation grade and scope,pollution control technical lines,environmental benefit accounting,and total emission control,and corresponding recommendations were put forward.

Demands for Coal-fired Power Will Reach New High

According to the new report released by the International Energy Agency,as the pandemic starts to mitigate and the global economy gradually recovers,demand for power has been rising.In 2021,the world’s coal-fired power generation increased by 9%over the previous year,while in 2020 power generation fell by 4%.The report shows that the rising demands for power,coupled with inadequate low-carbon power generation have made many developed economies more dependent on fossil fuel power.The rise of natural gas prices to a historical high has also stimulated demand for coal.

Evaluating the Technical and Economic Feasibility of Adding a Power Recovery System to the Steam Condenser of a Lignite Coal-Fired Power Plant

Steam is the typical working fluid to drive turbo-generators in coal-fired power plants. It is an effective working fluid, but some of its energy is extracted in an unusable form when condensed. A Power Recovery Cycle (PRC) using a more volatile Secondary Working Fluid (SWF) added to the steam cycle could improve energy efficiency. PRCs have been applied to the flue gas and for combined cycle systems but not to traditional plant steam cycles. This paper details an analysis of adding a steam cycle PRC to a 500 MW lignite coal-fired power plant. A validated model of the plant was developed and PRCs using the three most attractive SWFs, benzene, methanol and hydrazine, were then added to the model. Adding a benzene, methanol, or hydrazine steam cycle PRC will produce an additional 59, 34, and 49 MW, respectively. An AACE Class 4 factored broad capital cost estimate and comparable operating costs and revenue estimates were developed to evaluate PRC feasibility. The benzene, methanol, and hydrazine processes had 2019 Net Present Values (NPVs) @12% of -$32, -$59, and +$35 million ± 40%, respectively. Thus, a PRC may be profitable at current or modest increases to U.S. Upper Midwest electricity prices of around $0.0667/kWh.

Mercury Emission From Coal-fired Power Plants in China

燃煤是最大的人为汞排放源之一，燃煤电厂的汞排放控制问题也越来越为人们所关注。该文将目前公布的中国电厂的汞排放数据进行筛选汇总，得到18个电厂的汞排放数据，通过对比和分析，总结出了符合我国燃煤电厂特点的一般性汞排放规律。结果表明：与美国煤种相比，我国的燃煤具有低氯、高灰的特性，这不利于汞的排放控制；循环流化床燃烧可能会因燃尽率的不同而较煤粉炉燃烧易获得较高的Hgp；空气污染控制设备的使用能够有效地减少汞排放，选择性催化还原＋静电除尘器／布袋除尘器＋石灰石-石膏湿法脱硫（SCR＋ESP／FF＋WFGD）组合的平均脱汞率可达71．48％；SCR的大规模应用可能会将汞大量转移到飞灰和脱硫石膏中，带来二次污染的问题。