scholarly journals Research Progress on Control and Removal Technology of SO3 of Coal-fired Power Plants

2019 ◽  
Vol 118 ◽  
pp. 01036
Author(s):  
Xiuru Liu ◽  
Yiqing Sun ◽  
Fangming Xue ◽  
Jingcheng Su ◽  
jiangjiang Qu ◽  
...  

SO3 is one of pollutants in flue gas of coal power plants. It mainly derived from coal combustion in boiler and selective catalytic reduction denitrification system. The content of SO3 in flue gas were influenced by the combustion mode, sulfur content in fuel, composition of denitrification catalyst and fly ash. SO3 and water vapour generated H2SO4 droplets. Sulfate secondary particles in atmosphere could cause haze, acid rain and other disastrous weather. High concentration of SO3 could cause blockage and corrosion and affect the safe operation of the units. The generation mechanism of SO3 was discussed. The latest research progress on control and removal technology of SO3 was summarized. The study in this paper provides a reference for pollutant treatment in coal-fired power plants.

2020 ◽  
Vol 201 ◽  
pp. 106340 ◽  
Author(s):  
Ida Masoomi ◽  
Hiroyuki Kamata ◽  
Akinori Yukimura ◽  
Kiyohito Ohtsubo ◽  
Marc Oliver Schmid ◽  
...  

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.


2018 ◽  
Vol 245 ◽  
pp. 07014 ◽  
Author(s):  
Evgeny Ibragimov ◽  
Sergei Cherkasov

The article presents data on the calculated values of improving the efficiency of fuel use at the thermal power plant as a result of the introduction of a technical solution for cooling the flue gases of boilers to the lowest possible temperature under the conditions of safe operation of reinforced concrete and brick chimneys with a constant value of the flue gas temperature, when changing the operating mode of the boiler.


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.


Buildings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 225 ◽  
Author(s):  
Agnieszka Michalik ◽  
Joanna Babińska ◽  
Filip Chyliński ◽  
Artur Piekarczuk

The paper presents the results of research on the properties of fly ashes from the process of flue gas denitrification by selective non-catalytic reduction (SNCR), consisting of dosing urea into the coal combustion chamber. The research was carried out on two types of fly ash: Silica fly ash from flue gas denitrification and ash from a traditional boiler without the flue gas denitrification process. The scope of comparative studies included physicochemical and structural features of ashes, as well as slurries and mortars with the addition of ashes. Fly ash from denitrification, whose ammonia content at the time of sampling was 75 mg/kg at the maximum, was examined. Our own research has shown that fly ash from flue gas denitrification is characterized by a higher value of losses on ignition and ammonia content in comparison to ashes without denitrification. It was shown that the ammonia content in the analyzed range does not limit the use of fly ash as an additive to cement and concrete.


2017 ◽  
Vol 17 (7) ◽  
pp. 4477-4491 ◽  
Author(s):  
Qiao Ma ◽  
Siyi Cai ◽  
Shuxiao Wang ◽  
Bin Zhao ◽  
Randall V. Martin ◽  
...  

Abstract. High concentration of fine particles (PM2.5), the primary concern about air quality in China, is believed to closely relate to China's large consumption of coal. In order to quantitatively identify the contributions of coal combustion in different sectors to ambient PM2. 5, we developed an emission inventory for the year 2013 using up-to-date information on energy consumption and emission controls, and we conducted standard and sensitivity simulations using the chemical transport model GEOS-Chem. According to the simulation, coal combustion contributes 22 µg m−3 (40 %) to the total PM2. 5 concentration at national level (averaged in 74 major cities) and up to 37 µg m−3 (50 %) in the Sichuan Basin. Among major coal-burning sectors, industrial coal burning is the dominant contributor, with a national average contribution of 10 µg m−3 (17 %), followed by coal combustion in power plants and the domestic sector. The national average contribution due to coal combustion is estimated to be 18 µg m−3 (46 %) in summer and 28 µg m−3 (35 %) in winter. While the contribution of domestic coal burning shows an obvious reduction from winter to summer, contributions of coal combustion in power plants and the industrial sector remain at relatively constant levels throughout the year.


Author(s):  
Soumya Jyoti Chatterjee ◽  
Goutam Khankari ◽  
Sujit Karmakar

The comparative performance study is carried out for 500 MW Supercritical (SupC) Oxy-Coal Combustion (OCC) and Air-Coal Combustion (ACC) power plants with membrane-based CO2 capture at the fixed furnace temperature. The proposed configurations are modelled using a computer-based analysis software 'Cycle-Tempo' at different operating conditions, and the detailed thermodynamic study is done by considering Energy, Exergy, and Environmental (3-E) analysis. The result shows that the net energy and exergy efficiencies of ACC power plants with CO2 capture are about 35.07 % and 30.88 %, respectively, which are about 6.44 % and 5.77 % points, respectively higher than that of OCC power plant. Auxiliary power consumption of OCC based power plant is almost 1.97 times more than that of the ACC based plant due to huge energy utilization in the Air Separation Unit (ASU) of OCC plant which leads to performance reduction in OCC plant. However, environmental benefit of OCC based power plant is more than that of ACC based power plant with respect to CO2 emission. OCC plant emits about 0.164 kg/kWh of CO2 which is approximately 16.75 times lower than the CO2 emission in ACC based power plant. It is also analyzed that the performance of the CO2 Capture Unit (CCU) for the OCC based plant is about 3.65 times higher than the ACC based power plant due to higher concentration of CO2 (nearly 80.63%) in the flue gas emitting from OCC plant. The study also reveals that the auxiliary power consumption per kg of CO2 capture of the OCC based plant is about 0.142 kWh/kg, which is approximately 0.06 times lower than the ACC based plant. The higher performance of the OCC based power plant is found at lower value of flue gas recirculation due to the fact that reduction in exergy destruction at the mixing zone of the combustor is higher than the increase in exergy destruction of the heat exchangers at higher furnace exit temperature. But the metallurgical temperature limit of boiler tube materials restricts the use of the higher value of furnace temperature. OCC based power plant with CO2 capture can be preferred over ACC based plant with CO2 capture due to higher environmental benefits towards mitigating CO2, the key greenhouse gas on earth in spite of exhibiting lesser energy and exergy efficiencies.


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