Analysis of Foreign Experience in Using Flue Gas Purification Systems at Waste-to-Energy Plants

Vestnik MEI ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 11-19
Author(s):  
Anton N. Efremov ◽  
◽  
Aleksey A. Dudolin ◽  

The existing method for selecting the structure of a power plant for thermally recycling municipal solid waste (MSW) in the Russian Federation does not address the matter of selecting all components of an energy complex operating on MSW, but places focus on determining the best accessible waste thermal neutralization technology. This generates the need to search for new methods and to select criteria of choosing the structure for each particular project. A comparative analysis of various structural schemes of waste-to-energy plants widely used outside of Russia will make it possible to reveal their main advantages and drawbacks, and to determine their application fields. The article describes the statistical indicators characterizing the operation of the flue gas purification system from acid gases, which can be applied in performing a feasibility study, intellectual property assessment, and in carrying out front-end engineering. For waste-to-energy plants constructed in an urban environment and aimed to operate with keeping to a minimum the gross emissions of acid gases into the atmospheric air, the use of a wet reactor system is recommended, which will ensure low emissions of HF, HCl, and SOx. The system with a wet reactor will make it possible to reduce gross emissions of harmful substances during the operation of large capacity waste-to-energy power plants and will be a justified choice in such case. In constructing medium capacity waste-to-energy plants (with a throughput of up to 350 000 t of MSW per annum), semi-dry and dry reactors can be used; for such plants, the technology involving the use of a semi-dry reactor is the most preferred one.

2020 ◽  
Vol 71 (4) ◽  
pp. 536-548 ◽  
Author(s):  
Wang Hui ◽  
Zhang Pu

In China, sintering flue gas has become the most important source of air pollution rather than burning coal-fired flue gas.The emission characteristics and removal efficiencies of various gaseous pollutants were studiedon a 180 m2 sintering equipped with a semi-dry oxidative desulfurization and denitrification system in Tangshang, Hebei province. The emission concentrations of particulate matter, fluoride,NOX and SO2were measured in the flue gas whilepolychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) were tested in both flue gas and dust ash at 100% and 60% loadconditions. The collections and analyses ofpollutantswere used by smoke sampler, TESTO350 and dioxin sampleraccording to national standards of China. The results shown that the average emission concentration of particulate matter, fluoride, NOX and SO2 in the inlet of the flue gas purification system were 47.4 mg/m3, 0.12 mg/m3, 150 mg/m3 and 521 mg/m3 while the emission concentrations in the outlet were 1.2 mg/m3, 0.07 mg/m3, 24 mg/m3 and 20 mg/m3,respectively. Through the flue gas purification system, the PCDD/Fs concentrations were reduced from 23.12 ng/m3to 1.14 ng/m3at100% load and from 12.25 ng/m3 to 0.84 ng/m3at60% load. The PCDD/Fs concentrations in the dust ash were about 178.56~197.21 ng/kg. Thedesulfurization and denitrification system significant reduced effect on the emission of particulate matter, fluoride, NOX, SO2 and PCDD/Fs with the value 97.5%, 41.7%, 84.0%, 96.2% and 95.1% at 100% load, respectively.The removal affects increases along the chlorination degree of PCDD/Fs. Meanwhile,the different load influenced the emission concentrations and removal rates of PCDD/Fs in the flue gas, the removal effects increases as the load increases. Although the desulfurization and denitrification system has good removal effects on various pollutants, the dioxins were enriched in the dust ashso as to cause secondary pollution.


Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 900
Author(s):  
Zhongjie Hu ◽  
Heng Zhou ◽  
Weili Zhang ◽  
Shengli Wu

This study investigated influences of the open/close states of pores and porosity distribution of activated coke on the mechanical strength of common activated coke for the purification of coal-fired flue gas by analyzing pore structure, abrasive resistance, and compression strengths of 9 types of desulfurization and denitration activated cokes. Research conclusions are conducive to disclosing the influences of porosity characteristics of activated coke for the purification of coal-fired flue gas on mechanical strength, decreasing the physical consumption of activated coke in the recycling of flue gas purification systems, and lowering the purification cost of coal-fired flue gas. According to research results, pores in the ranges of 0–2 nm and 2–500 nm of activated coke are further developed after recycling using the coal-fired flue gas purification system, and the average compression strength of activated coke is about 70% of the added fresh activated coke. However, the abrasive resistance of the recycled activated coke which has a smooth surface is higher than that of the fresh activated coke. Open pores are the main cause of reduced compression strength of activated coke. Open pores in the range of 2–500 nm can destroy the compression strength of activated coke the most. The open/close states of pores cause no significant impacts on the abrasive resistance of activated coke, but pores with diameters ranging from 0–2 nm can destroy the abrasive resistance of activated coke most significantly.


Author(s):  
S. V. Plashykhin ◽  
T. V. Bojko ◽  
D. N. Skladannyy ◽  
Ju. A. Zaporozhets ◽  
Artem S. Safiants

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2174
Author(s):  
Marta Marczak-Grzesik ◽  
Stanisław Budzyń ◽  
Barbara Tora ◽  
Szymon Szufa ◽  
Krzysztof Kogut ◽  
...  

The research presented by the authors in this paper focused on understanding the behavior of mercury during coal combustion and flue gas purification operations. The goal was to determine the flue gas temperature on the mercury emissions limits for the combustion of lignites in the energy sector. The authors examined the process of sorption of mercury from flue gases using fine-grained organic materials. The main objectives of this study were to recommend a low-cost organic adsorbent such as coke dust (CD), corn straw char (CS-400), brominated corn straw char (CS-400-Br), rubber char (RC-600) or granulated rubber char (GRC-600) to efficiently substitute expensive dust-sized activated carbon. The study covered combustion of lignite from a Polish field. The experiment was conducted at temperatures reflecting conditions inside a flue gas purification installation. One of the tested sorbents—tire-derived rubber char that was obtained by pyrolysis—exhibited good potential for Hg0 into Hg2+ oxidation, resulting in enhanced mercury removal from the flue. The char characterization increased elevated bromine content (mercury oxidizing agent) in comparison to the other selected adsorbents. This paper presents the results of laboratory tests of mercury sorption from the flue gases at temperatures of 95, 125, 155 and 185 °C. The average mercury content in Polish lignite was 465 μg·kg−1. The concentration of mercury in flue gases emitted into the atmosphere was 17.8 µg·m−3. The study analyzed five low-cost sorbents with the average achieved efficiency of mercury removal from 18.3% to 96.1% for lignite combustion depending on the flue gas temperature.


Sign in / Sign up

Export Citation Format

Share Document