97/02344 Flue gas desulfurization system for treating waste gases from combustion of fossil fuels or municipal refuse, especially in power plants

1997 ◽  
Vol 38 (3) ◽  
pp. 187
2018 ◽  
Vol 53 ◽  
pp. 04005 ◽  
Author(s):  
Ding Yang ◽  
Yi Luo ◽  
XingLian Ye ◽  
WeiXiang Chen ◽  
Jun Guo ◽  
...  

SO3 is one of the main precursors of atmospheric PM2.5, and its emission has attracted more and more attention in the industry. This paper briefly analyzes the harm of SO3 and the method of controlled condensation to test SO3. The effect of cooperative removal of SO3 by ultra-low emission technology in some coal-fired power plants has been tested by using the method of controlled condensation. The results show that the cooperative removal of SO3 by ultra-low emission technology in coal-fired power plants is effective. The removal rate of SO3 by low-low temperature electrostatic precipitators and electrostatic-fabric integrated precipitators can be exceeded 80%, while the removal rate of SO3 by wet flue gas desulfurization equipment displays lower than the above two facilities, and the wet electrostatic precipitator shows a better removal effect on SO3. With the use of ultra-low emission technology in coal-fired power plants, the SO3 emission concentration of the tail chimney reaches less than 1 mg / Nm3.


2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Ghulam Moeen Uddin ◽  
Syed Muhammad Arafat ◽  
Waqar Muhammad Ashraf ◽  
Muhammad Asim ◽  
Muhammad Mahmood Aslam Bhutta ◽  
...  

Abstract The emissions from coal power plants have serious implication on the environment protection, and there is an increasing effort around the globe to control these emissions by the flue gas cleaning technologies. This research was carried out on the limestone forced oxidation (LSFO) flue gas desulfurization (FGD) system installed at the 2*660 MW supercritical coal-fired power plant. Nine input variables of the FGD system: pH, inlet sulfur dioxide (SO2), inlet temperature, inlet nitrogen oxide (NOx), inlet O2, oxidation air, absorber slurry density, inlet humidity, and inlet dust were used for the development of effective neural network process models for a comprehensive emission analysis constituting outlet SO2, outlet Hg, outlet NOx, and outlet dust emissions from the LSFO FGD system. Monte Carlo experiments were conducted on the artificial neural network process models to investigate the relationships between the input control variables and output variables. Accordingly, optimum operating ranges of all input control variables were recommended. Operating the LSFO FGD system under optimum conditions, nearly 35% and 24% reduction in SO2 emissions are possible at inlet SO2 values of 1500 mg/m3 and 1800 mg/m3, respectively, as compared to general operating conditions. Similarly, nearly 42% and 28% reduction in Hg emissions are possible at inlet SO2 values of 1500 mg/m3 and 1800 mg/m3, respectively, as compared to general operating conditions. The findings are useful for minimizing the emissions from coal power plants and the development of optimum operating strategies for the LSFO FGD system.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4249
Author(s):  
Xuan Yao ◽  
Man Zhang ◽  
Hao Kong ◽  
Junfu Lyu ◽  
Hairui Yang

After the implementation of the ultra-low emissions regulation on the coal-fired power plants in China, the problem of the excessive ammonia-slipping from selective catalytic reduction (SCR) seems to be more severe. This paper analyzes the operating statistics of the coal-fired plants including 300 MW/600 MW/1000-MW units. Statistics data show that the phenomenon of the excessive ammonia-slipping is widespread. The average excessive rate is over 110%, while in the small units the value is even higher. A field test data of nine power plants showed that excessive ammonia-slipping at the outlet of SCR decreased following the flue-gas process. After most ammonia reduced by the dust collector and the wet flue-gas desulfurization (FGD), the ammonia emission at the stack was extremely low. At same time, a method based on probability distribution is proposed in this paper to describe the relationship between the NH3/NOX distribution deviation and the De–NOX efficiency/ammonia-slipping. This paper also did some original work to solve the ammonia-slipping problem. A real-time self-feedback ammonia injection technology using neural network algorithm to predict and moderate the ammonia distribution is proposed to decrease the NH3/NOX deviation and excessive ammonia-slipping. The technology is demonstrated in a 600-MW unit and works successfully. The excessive ammonia-slipping problem is well controlled after the implementation of the technology.


Author(s):  
Armin Main ◽  
Thomas Maghon

The efforts for reducing CO2 Emissions into atmosphere and increasing costs for fossil fuels concepts are the drivers for Energy from Waste (EfW) facilities with higher plant efficiency. In the past steam parameters for EfW were requested mainly at 40 bars and 400 °C (580 psi and 752 F). In case of coal fired power plants at the same location as the EfW facilities higher steam parameters at 90 bar, 520 °C (1305 psi, 968 F) have been used for the design of stoker and boiler. This long-term experience with higher steam parameters is the platform for the todays and future demand in higher plant efficiency. Increase in EfW plant efficiency is achievable by increasing temperature and pressure of live steam going along with optimized combustion conditions when using well proven grate technology for waste incineration. On the other hand higher steam parameters result in higher corrosion rates on the boiler tubes and the optimization of the combustion conditions are limited by the burn out quality requirements of slag and flue gas. Advantages and disadvantages have therefore to be balanced carefully. This paper will present different measures for optimized boiler and combustion conditions compared to an EfW plant with live steam at 40 bars and 400 °C (580 psi and 752 F) and 60% excess of combustion air. Plants operated at these conditions have very low maintenance costs created by corrosion of boiler tubes and show performance with very high availability. The following parameters and experiences will be evaluated: - reduction of excess air; - flue gas temperature at boiler outlet; - higher steam parameters (pressure and temperature); - heating surfaces for steam superheating in the radiation boiler section; - steam reheating; - external superheaters using auxiliary fuels. The comparison of the different methods for increasing the efficiency together with resulting technology challenges incorporates the experiences from modern EfW reference facilities built in Naples/Italy, Ruedersdorf (Berlin)/Germany and Heringen/Germany.


2008 ◽  
Vol 89 (11) ◽  
pp. 1025-1032 ◽  
Author(s):  
Yi Zhong ◽  
Xiang Gao ◽  
Wang Huo ◽  
Zhong-yang Luo ◽  
Ming-jiang Ni ◽  
...  

2012 ◽  
Vol 518-523 ◽  
pp. 2576-2579 ◽  
Author(s):  
Zhong Gen Li ◽  
Xin Bin Feng ◽  
Guang Hui Li ◽  
Run Sheng Yin ◽  
Ben Yu

Mercury distribution and stable isotope composition in solid samples of two coal-fired power plants in Guizhou province were determined. Results shown electrostatic precipitator (ESP) has mercury removal efficiency between 29.53% to 58.41%, and wet flue gas desulfurization (WFGD) between 12.29% to 58.60%, mercury removal efficiency of ESP and WFGD mainly depends on the coal properties. Most mercury (70% to 88%) in coal was captured by the combination of ESP+WFGD. Mercury in fly ash and gypsum were much heavier in isotope composition compared to the coal, hints mercury escaped into atmosphere was enriched in lighter mercury isotopes.


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