The Chemical Principle of Green Coal Power

Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP （green coal power） is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG （simulated flue gases）. It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.

Tolerance Comparison Among Selected Spirulina Strains Cultured Under High Carbon Dioxide and Coal Power Plant Flue Gas Supplements

In order to explore the changes in the growth and protein contents of Spirulina and obtain a proper strain for the fixation of carbon dioxide(CO2 from flue gas,the strains isolated from the Spirulina farms and the strain 208 were cultured under different aeration conditions including no CO2,10%CO2 and coal power plant flue gas supplements.The physiological indexes including filament length,biomass yield and chlorophyll a,soluble protein and phycocyanin contents were determined,respectively.When cultured without CO2 supplement,the strain 4-5 exhibited the highest biomass yield(1.880 g L^(−1)and a specific growth rate(0.367 d−1.However,the specific growth rate of all strains decreased significantly when they were cultured under 10%CO2 and unfiltered coal power plant flue gas supplements.Considerable differences were noted in the performance of the experimental microalgal strains under different contemporaneous conditions.The strain 7-8 achieved the highest biomass yield(1.603 g L^(−1)and relatively high phycocyanin content(7.1%)under 10%CO2 supplement.We noted that strain 4-5 had the highest specific growth rate(0.182 d−1 and biomass yield(0.43 g L^(−1)under coal power plant flue gas supplement.Strain 6-10 displayed the highest soluble protein content(66.02%),and strain 7-8 showed the highest phycocyanin content(9.28%)under coal power plant flue gas supplement.

Approach to reducing the effect of bone-coal power station on radiation environment

The effect of two bone-coal power stations(6MWe) on environment was investigated within the scope of the dose contribution caused by various radionucildes in different ways.It is found that the best measures to reduce the effect of bone-coal power station on radiation environment include to select a fine boiler system and a comprehensive utilization of the bone-coal cinder(BCC),soot and ash in the catchers.

The collective dose equivalent in evaluated region of bone-coal power stations and bone-coal shafts

During 1991-1993, the radioactivity levels of the bone-coal mines were investigated in Hubei, Hunan, Ji-angxi, Zhejiang and Anhui Provinces, respectively, where the reserve of bone-coal is about 90% of our country’s total reserve. The annual additional collective dose equivalent within 80km evaluated region of bone-coal power stations in Nijiangkou and Anren is 1.7 and 1.9 man·mSv, respectively, and that of Zhuantanyan bone-coal shaft is 1.4 man·mSv. The collective dose equivalent caused by bone-coal cinder brick produced for 25 years in the five prov-inces is 1.6×105 man Sv.

Radioactivity level of the ambient environment of Anren bone-coal power station

The radioactivity level of the ambient environment of Anren Bone-coal Power Station (BCPS) was investigated systematically. The γ radiation dose rate level in the environment, the content of 238U and 226Ra in the ambient soil and the farmland in the direction of downwind, the concentrations of 238U. 232Th. 226Ra 40K and 222Rn as well as α potential energy in air, and the concentrations of natural U and Th in effluent are all higher than the corresponding values of the reference site. The additional annual effective dose equivalent to the residents living in the houses made of bone-coal cinder brick is 2.7 mSv.

Data-driven modeling of power generation for a coal power plant under cycling

Increased penetration of renewables for power generation has negatively impacted the dynamics of conventional fossil fuel-based power plants.The power plants operating on the base load are forced to cycle,to adjust to the fluctuating power demands.This results in an inefficient operation of the coal power plants,which leads up to higher operating losses.To overcome such operational challenge associated with cycling and to develop an optimal process control,this work analyzes a set of models for predicting power generation.Moreover,the power generation is intrinsically affected by the state of the power plant components,and therefore our model development also incorporates additional power plant process variables while forecasting the power generation.We present and compare multiple state-of-the-art forecasting data-driven methods for power generation to determine the most adequate and accurate model.We also develop an interpretable attention-based transformer model to explain the importance of process variables during training and forecasting.The trained deep neural network(DNN)LSTM model has good accuracy in predicting gross power generation under various prediction horizons with/without cycling events and outperforms the other models for long-term forecasting.The DNN memory-based models show significant superiority over other state-of-the-art machine learning models for short,medium and long range predictions.The transformer-based model with attention enhances the selection of historical data for multi-horizon forecasting,and also allows to interpret the significance of internal power plant components on the power generation.This newly gained insights can be used by operation engineers to anticipate and monitor the health of power plant equipment during high cycling periods.

Impact of coal power generation on the characteristics and risk of heavy metal pollution in nearby soil

Introduction:The development of coal power base(CPB)poses a severe challenge to the soil.We conducted a soil survey in Xilinhot CPB,to evaluate and analyze the pollution characteristics,potential ecological risk,and sources of six heavy metals(As,Pb,Cu,Zn,Mn,and Cd)in soil by using Geo-accumulation index,revised Nemerow integrated pollution index(RNIPI),and potential ecological risk index(RI).Outcomes/other:The results showed that the pollution of Cd and As were dramatic.The mean of Cd and As were 1.11 mg·kg^(-1) and 25.13 mg·kg^(-1),which were 42.55 times and 4.41 times higher than its local background value.The Geo-accumulation indices showed the contamination degree of Cd was strong and As was moderate,and the status of Cu,Pb,Zn,and Mn were uncontaminated.Xilinhot was strongly contaminated based on its RNIPI and RI values.Discussion:The accumulations of As,Pb,and Cd were mainly associated with anthropogenic sources,including coal mining and combustion,and industrial exhaust emissions.Cu,Mn,and Zn were primarily originated from the parent material(natural sources).Conclusion:This study provides scientific basis and effective countermeasures for the prevention and control of soil pollution in surrounding areas of CPB.

A U.S.‒China coal power transition and the global 1.5℃ pathway

As the world seeks to increase ambition rapidly to limit global warming to 1.5℃,joint leadership from the world's largest greenhouse gas(GHG)emitters-the United States(U.S.)and China-will be critical to deliver significant emissions reductions from their own countries as well as to catalyze increased international action.After a period of uncertainty in international climate policy,these countries now both have current leadership that supports ambitious climate action.In this context,a feasible,high-impact,and potentially globally catalytic agreement by the U.S.and China to transition away from coal to clean energy would be a major contribution toward this global effort.We undertake a plant-by-plant assessment in the power sector to identify practical coal retirement pathways for each country that are in line with national priorities and the global 1.5℃ target.Our plant-by-plant analysis shows that the 1.5℃-compatible pathways may result in an average retirement age of 47 years for the U.S.coal plants and 22 years for Chinese coal plants,raising important questions of how to compare broader economic,employment,and social impacts.We also demonstrate that such pathways would also lead to significant emissions reductions,lowering overall global energy-related CO_(2) emissions by about 9%in 2030 relative to 2020.A catalytic effect from the possibility of other countries taking compatible actions is estimated to reduce global emissions by 5.1 Gt CO_(2) in 2030 and by 10.1 Gt CO_(2) in 2045.

Sliding Mode Predictive Control of Main Steam Pressure in Coal-fired Power Plant Boiler

Since the combustion system of coal-fired boiler in thermal power plant is characterized as time varying, strongly coupled, and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional integral derivative (PID) control scheme. For the characteristics of the main steam pressure in coal-fired power plant boiler, the sliding mode control system with Smith predictive structure is proposed to look for performance and robustness improvement. First, internal model control (IMC) and Smith predictor (SP) is used to deal with the time delay, and sliding mode controller (SMCr) is designed to overcome the model mismatch. Simulation results show the effectiveness of the proposed controller compared with conventional ones.

Estimate of arsenic emission amount from the coal power stations in China

To study the amount of arsenic emission from the coal power stations (mainly Permo-Carboniferous coal) in China in different combustion conditions, the arsenic con-tent of the coal, the fly ash and the cinder in high- tempera-ture power stations as well as mid-low temperature power stations have been analyzed. This note provides a rough es-timate of the total amount of arsenic emission as well as emission ratio from steam coal combustion in China. The results show that by combustion of 1 t of Permo-Carbonif- erous coal (containing roughly 5 mg/kg arsenic), high-tem- perature power stations emit roughly 0.40 g arsenic into the atmosphere and the arsenic emission rate is about 7.70%; mid-low power stations emit roughly 0.15 g arsenic into the atmosphere and the arsenic emission rate is about 2.97%. A total of 600 million tons coal is burnt annually in China power stations, and the coal comes mainly from Permo- Carboniferous depositing in the North China Plate and northwest China coal mines. Taking the average arsenic con-tent of the coal used at the value of 5 mg/kg, the total annual arsenic emission from steam coal combustion into the at-mosphere is about 195.0 t. Most of the arsenic in coal can be released in the process of coal combustion, and the most of the released arsenic can be seized by the fly ash and then both of them are seized by the dust catcher of power station, so the arsenic emission ratio to the atmosphere is declined; in addition, research on the arsenic emission amount and emis-sion rules from the coal power stations in China should go on the coal power stations with the dry-process dust catchers by the experiments results. In the wet process of dust catcher, 20% of the arsenic in the fly ash is dissolved in the water of sedimentation tank in high-temperature power station; in the mid-low temperature power station there are 70% of the arsenic in the fly ash dissolved in the water of sedimentation tank, this is an important source of arsenic pollution in envi-ronment and should not be overlooked. The arsenic emission rate in the process of coal cineration in the laboratory is higher than the actual arsenic emission rate of power station.

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。

Improve power quality of coal mine power network based on gray system theory

Unified Power Quality Controller（UPQC） was proposed to comprehensively improve power quality of coal mine power network and its basic structure and operation principle was introduced. In order to overcome time lag of Active Power Filter（APF） in compensating harmonic and reactive current, a novel method based on gray system theory was proposed to predict harmonic current and other distortion component. The mathematical model of component to be compensated was constructed by data sequence of distortion component, which could exactly forecast compensation signal of next period. The optimal control strategy was selected according to the principle of output signal approaching component to be compensated as near as possible. Before predicating each time the oldest data was eliminated while the latest data was added to data sequence. Then new predication model was established once again. The results show that the method can always construct mathematical model with variation of system parameters, reflect the latest state of system and not increase calculation quantity. The feasible and effective control strategy can improve power quality of coal mine power network.

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.

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.

Chatter free sliding mode control of a chaotic coal mine power grid with small energy inputs

An augmented proportional-integral sliding surface was designed for a sliding mode controller. A chatter free sliding mode control strategy for a chaotic coal mine power grid was developed. The stability of the control strategy was proven by Lyapunov stability theorem. The proposed sliding mode control strategy eliminated the chattering phenomenon by replacing the sign function with a saturation function, and by replacing the constant coefficients in the reaching law with adaptive ones. An immune genetic algorithm was used to optimize the parameters in the improved reaching law. The cut-in time of the controllers was optimized to reduce the peak energy of their output. Simulations showed that the proposed sliding mode controller has good, chatter flee performance.

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.

Ultimate Composition of Main Chinese Power Coals

Calculations and analyses are made for the ultimate composition of 158 Chinese power coals. The results reveal that the carbon content on as received basis, Cr, increases linearly with the increase of the low heating value Qnot,a, on as received basis; the hydrogen content on as received basis, Hr, first increases with the increase of the volatile content on dry ash free basis Vdaf （Vdaf 〈 33.0%） and then decreases （Vdaf 〉 33.0%）; the oxygen content on as received basis, Oar, increases linearly with the increase of Vau, ranging between 2.0% and 12.5%. By comparison, the nitrogen content on as received basis N of bituminous and lean coal is higher, while the sulfur content on as received basis Sar Of anthracite is higher than bituminous coal, lean coal and lignite. The hydrogen on as received basis Hr is important for the conversion between low heating value and high heating value on as received basis for Chinese power coals, and Sr is important for the calculation of high heating value from the oxygen bomb heat value for Chinese power coals.

Supply Chain Cooperation between Coal Enterprise and Electric Power Enterprise in China

Based on the two-stage Stackelberg game method, value creation of supply chain cooperation between coal enterprise and power utilities is studied by formulating profit functions of coal and power enterprises and calculating the maximum profit. According to the analysis, it is found that the profit from supply chain cooperation between coal and power enterprises is more than that of non- cooperation. The cooperation is validated to be beneficial for both units; however, the profit is mainly taken by the power enterprise. Thus, it is necessary to set up the incentive mechanism to distribute cooperation value between coal and power enterprises to promote their continual cooperation.

The Way to Relieve Tense Supply Situation of Power and Coal in China

This paper introduces the situation of coal and power production, the tense supply of powercoal and deteriorated coal quality in 2004, analyzes the causes of tense supply of power and coal, one ofwhich is due to the government regulated power tariff against rapid escalation of coal price that powerenterprises can hardly afford. It also presents some policy proposals to relieve the contradiction betweencoal and power, including to intensify macroscopic regulation between industries and regions, solve theproblem of power coal transportation and reduction or exemption of tax on coal industry and circulationlinks, through secondary distribution to regulate profit difference among industries.