scholarly journals Sulphite measurement and its influence on Hg behaviour in wet-limestone flue-gas desulphurization

Clean Energy ◽  
2020 ◽  
Author(s):  
Ida Masoomi ◽  
Sophia Bruttel ◽  
Marc Oliver Schmid ◽  
Günter Scheffknecht
Keyword(s):  
Gas Phase ◽  
Gas Sensor ◽  
Measurement Technique ◽  
Flue Gas ◽  
Sulphur Dioxide ◽  
Reducing Agent ◽  
Characteristic Wavelength ◽  
Light Absorbance ◽  
Flue Gas Desulphurization

Abstract The most abundant and typical reducing agent for oxidized mercury in the slurry of wet flue-gas desulphurization (FGD) is the absorbed sulphur dioxide (SO2), which is present as different species of bisulphite or sulphite, depending on the pH of the slurry. In this study, two different measurement principles for continuous sulphite measurement in the slurry of lab-scale FGD were investigated to check their feasibility to be implemented in a wet FGD. The first method is based on light absorbance at the characteristic wavelength of sulphite measurement using a spectrophotometer and, in the second method, sulphite is measured as sulphur dioxide using a gas sensor. In addition, the correlation of sulphite concentration and mercury (Hg) in the slurry can be shown by measuring sulphite semi-continuously. It was concluded that using a spectrophotometer leads to distorted results. In contrast, measuring sulphite as SO2 in the gas phase proved to be more selective. The implementation of the measurement technique in the lab-scale FGD showed promising results for sulphite measurement. Thus, the correlation of Hg and sulphite concentration could be shown at different synthetic slurries containing different halides. Using a slurry without halides demonstrated the ambivalent influence of sulphite in reactions involving Hg, in which sulphite acts as a ligand for Hg complexes as well as a reducing agent, depending on the existing concentration. However, in the presence of halides, the role of sulphite was less significant.

scholarly journals Multimodel Anomaly Identification and Control in Wet Limestone-Gypsum Flue Gas Desulphurization System

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiaoli Li ◽  
Quanbo Liu ◽  
Kang Wang ◽  
Fuqiang Wang ◽  
Guimei Cui ◽  
...  
Keyword(s):  
Flue Gas ◽  
Sulphur Dioxide ◽  
High Performance ◽  
Power Plants ◽  
Control Method ◽  
Control Strategies ◽  
Air Pollutant ◽  
Process Data ◽  
Whole Process ◽  
Flue Gas Desulphurization

Sulphur dioxide, as one of the most common air pollutant gases, brings considerable numbers of hazards on human health and environment. For the purpose of reducing the detrimental effect it brings, it is of urgent necessity to control emissions of flue gas in power plants, since a substantial proportion of sulphur dioxide in the atmosphere stems from flue gas generated in the whole process of electricity generation. However, the complexity and nondeterminism of the environment increase the occurrences of anomalies in practical flue gas desulphurization system. Anomalies in industrial desulphurization system would induce severe consequences and pose challenges for high-performance control with classical control strategies. In this article, based on process data sampled from 1000 MW unit flue gas desulphurization system in a coal-fired power plant, a multimodel control strategy with multilayer parallel dynamic neural network (MPDNN) is utilized to address the control problem in the context of different anomalies. In addition, simulation results indicate the applicability and effectiveness of the proposed control method by comparing with different cases.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

scholarly journals The role of radiolysis in the modelling of C2H4O2 isomers and dimethyl ether in cold dark clouds

2020 ◽  
Vol 500 (3) ◽  
pp. 3414-3424
Author(s):  
Alec Paulive ◽  
Christopher N Shingledecker ◽  
Eric Herbst
Keyword(s):  
Gas Phase ◽  
Dimethyl Ether ◽  
Recent Observation ◽  
Cosmic Ray ◽  
Thermal Method ◽  
Dark Clouds ◽  
Ice Surface ◽  
Dust Grain ◽  
Complex Organic

ABSTRACT Complex organic molecules (COMs) have been detected in a variety of interstellar sources. The abundances of these COMs in warming sources can be explained by syntheses linked to increasing temperatures and densities, allowing quasi-thermal chemical reactions to occur rapidly enough to produce observable amounts of COMs, both in the gas phase, and upon dust grain ice mantles. The COMs produced on grains then become gaseous as the temperature increases sufficiently to allow their thermal desorption. The recent observation of gaseous COMs in cold sources has not been fully explained by these gas-phase and dust grain production routes. Radiolysis chemistry is a possible non-thermal method of producing COMs in cold dark clouds. This new method greatly increases the modelled abundance of selected COMs upon the ice surface and within the ice mantle due to excitation and ionization events from cosmic ray bombardment. We examine the effect of radiolysis on three C2H4O2 isomers – methyl formate (HCOOCH3), glycolaldehyde (HCOCH2OH), and acetic acid (CH3COOH) – and a chemically similar molecule, dimethyl ether (CH3OCH3), in cold dark clouds. We then compare our modelled gaseous abundances with observed abundances in TMC-1, L1689B, and B1-b.

The Properties of Flue Gas Desulphurization (FGD) Gypsum

2011 ◽  
Vol 105-107 ◽  
pp. 2204-2208 ◽  
Author(s):  
Run Xia Hao ◽  
Xiao Yan Guo
Keyword(s):  
Mechanical Properties ◽  
Flue Gas ◽  
Steel Slag ◽  
Optical Microscope ◽  
Cementitious Material ◽  
Fgd Gypsum ◽  
Technical Performance ◽  
Slag Powder ◽  
Steel Slag Powder ◽  
Flue Gas Desulphurization

The properties of flue gas desulphurization (FGD) gypsum were analysized by Thermo-gravimetry/differential scanning calorimetry (TG/DSC), technical performance analysis, optical microscope and Scanning electron microscope (SEM). Mechanical properties of FGD gypsum-steel slag powder cementitious material were researched. The results revealed that FGD gypsum have similar moisture content, major component CaSO4·2H2O with natural gypsum, and has better technical performance than natural gypsum. The results of optical microscope and SEM of the FGD gypsum hydration support this further. When the dosage of steel slag powder is 15%, containing activator ,better mechanical properties can be obtained. Key words: FGD gypsum, Property, Cementitious material

Tangxian Jidong Cement Co., Ltd. SNCR DeNOx Engineering Practice

2013 ◽  
Vol 726-731 ◽  
pp. 2342-2346 ◽  
Author(s):  
Shao Hua Ling ◽  
Chang Yong Jing ◽  
Jing Ma ◽  
Li Juan Zhang
Keyword(s):  
Flue Gas ◽  
Reducing Agent ◽  
Engineering Practice ◽  
System Configuration ◽  
Process Characteristics ◽  
Detailed Explanation ◽  
Actual Operating ◽  
Ammonia Slip ◽  
Flue Gas Denitrification

Tang xian in Hebei Jidong Cement Co., Ltd. flue gas denitrification treatment works, the project uses ammonia as a reducing agent SNCR DeNOx technology. A detailed explanation of the the SNCR process characteristics and system configuration, The analysis for actual operating results of the engineering. The results show: After treatment NOx concentration is less than 200 mg/Nm3, Denitrification efficiency reach 72.82%, Ammonia slip less than 0.9mg/Nm3, Engineering put into operation, About a year reduces emission NOx 1430 tons.

Study on Mechanism of Flue Gas Desulfuration by Using Liquid-Phase Biochemical Method

2011 ◽  
Vol 356-360 ◽  
pp. 1556-1560
Author(s):  
Zhi An Liu ◽  
Ying Chang ◽  
Peng Wang ◽  
Jlan Jun Jia ◽  
Qi Wang Liu
Keyword(s):  
Flue Gas ◽  
Rate Increase ◽  
The Self ◽  
Inlet Concentration ◽  
Critical Factors ◽  
Biochemical Method ◽  
Solution Ph ◽  
Flue Gas Desulfuration ◽  
Increasing Temperature ◽  
Flue Gas Desulphurization

Wet Biochemical Flue Gas Desulphurization technique (WB-FGD) is combined both catalyst of transition metal with microbial metabolize to achieve flue gas desulphurization. In the self-designed device of power plant flue gas desulphurization, study the desulphurization kinetics according to the absorption solution pH, Fe3+concentration, inlet concentration of SO2, temperature and other factors. The results show that: Concentration of Fe3+is the most critical factors in the desulphurization process, the desulphurization efficiency is decreased with the increasing of Fe3+concentration, which in the range of 0~0.01mol·L-1, and the desulphurization efficiency do not change significantly with the further increasing of the concentration of Fe3+.the desulphurization efficiency is decreased with the increasing concentration of H+when pH of the solution in the range of 1.5~3.5. The efficiency of desulphurization decrease with the increasing concentration of SO2, which in the range of 1145-3432mg·L-1. The oxidation rate increase with the increasing temperature at 20~40°C.The kinetic equation and controllable parameters of changes of Fe3+concentration are obtained according to the experimental data in WB-FGD.

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